Moore, Carter (Boise, ID, US)
Folkes, Elon (Boise, ID, US)
Castor, Terry (Boise, ID, US)

Plaque It! Sponsored by: Flash of Genius

11/471975

08/19/2008

06/21/2006

Images are available in PDF form when logged in. To view PDFs, Login  or  Create Account (Free!)

View patents that cite this patent

Click for automatic bibliography generation

Micron Technology, Inc. (Boise, ID, US)

451/8

451/6, 438/5, 451/41, 451/10, 451/5

B24B1/00; B24B49/00; B24B51/00

438/5-18, 451/8, 451/6, 451/4, 451/41, 451/10, 700/299, 451/63, 451/59, 451/36, 451/57, 340/680

4498345	Method for measuring saw blade flexure	February, 1985	Dyer et al.
4501258	Kerf loss reduction in internal diameter sawing	February, 1985	Dyer et al.
4502459	Control of internal diameter saw blade tension in situ	March, 1985	Dyer
4971021	Apparatus for cutting semiconductor crystal	November, 1990	Kubotera et al.
5036015	Method of endpoint detection during chemical/mechanical planarization of semiconductor wafers	July, 1991	Sandhu et al.
5069002	Apparatus for endpoint detection during mechanical planarization of semiconductor wafers	December, 1991	Sandhu et al.
5081796	Method and apparatus for mechanical planarization and endpoint detection of a semiconductor wafer	January, 1992	Schultz
5163334	Circular saw testing technique	November, 1992	Li et al.
5222329	Acoustical method and system for detecting and controlling chemical-mechanical polishing (CMP) depths into layers of conductors, semiconductors, and dielectric materials	June, 1993	Yu
5232875	Method and apparatus for improving planarity of chemical-mechanical planarization operations	August, 1993	Tuttle et al.
5234867	Method for planarizing semiconductor wafers with a non-circular polishing pad	August, 1993	Schultz et al.
5240552	Chemical mechanical planarization (CMP) of a semiconductor wafer using acoustical waves for in-situ end point detection	August, 1993	Yu et al.
5244534	Two-step chemical mechanical polishing process for producing flush and protruding tungsten plugs	September, 1993	Yu et al.
5245790	Ultrasonic energy enhanced chemi-mechanical polishing of silicon wafers	September, 1993	Jerbic
5245796	Slurry polisher using ultrasonic agitation	September, 1993	Miller et al.
RE34425	Method and apparatus for mechanical planarization and endpoint detection of a semiconductor wafer	November, 1993	Schultz
5413941	Optical end point detection methods in semiconductor planarizing polishing processes	May, 1995	Koos et al.
5421769	Apparatus for planarizing semiconductor wafers, and a polishing pad for a planarization apparatus	June, 1995	Schultz et al.
5433649	Blade position detection apparatus	July, 1995	Nishida et al.
5433651	In-situ endpoint detection and process monitoring method and apparatus for chemical-mechanical polishing	July, 1995	Lustig et al.
5439551	Chemical-mechanical polishing techniques and methods of end point detection in chemical-mechanical polishing processes	August, 1995	Meikle et al.
5449314	Method of chimical mechanical polishing for dielectric layers	September, 1995	Meikle et al.
5486129	System and method for real-time control of semiconductor a wafer polishing, and a polishing head	January, 1996	Sandhu et al.
5514245	Method for chemical planarization (CMP) of a semiconductor wafer to provide a planar surface free of microscratches	May, 1996	Doan et al.
5533924	Polishing apparatus, a polishing wafer carrier apparatus, a replacable component for a particular polishing apparatus and a process of polishing wafers	July, 1996	Stroupe et al.
5540810	IC mechanical planarization process incorporating two slurry compositions for faster material removal times	July, 1996	Sandhu et al.
5573442	Apparatus for measuring a cutting blade width in a cutting apparatus	November, 1996	Morita et al.
5609718	Method and apparatus for measuring a change in the thickness of polishing pads used in chemical-mechanical planarization of semiconductor wafers	March, 1997	Meikle
5618381	Multiple step method of chemical-mechanical polishing which minimizes dishing	April, 1997	Doan et al.
5618447	Polishing pad counter meter and method for real-time control of the polishing rate in chemical-mechanical polishing of semiconductor wafers	April, 1997	Sandhu
5624303	Polishing pad and a method for making a polishing pad with covalently bonded particles	April, 1997	Robinson
5632666	Method and apparatus for automated quality control in wafer slicing	May, 1997	Peratello et al.
5643048	Endpoint regulator and method for regulating a change in wafer thickness in chemical-mechanical planarization of semiconductor wafers	July, 1997	Iyer
5643060	System for real-time control of semiconductor wafer polishing including heater	July, 1997	Sandhu et al.
5645471	Method of texturing a substrate using an abrasive article having multiple abrasive natures	July, 1997	Strecker
5658183	System for real-time control of semiconductor wafer polishing including optical monitoring	August, 1997	Sandhu et al.
5658190	Apparatus for separating wafers from polishing pads used in chemical-mechanical planarization of semiconductor wafers	August, 1997	Wright et al.
5663797	Method and apparatus for detecting the endpoint in chemical-mechanical polishing of semiconductor wafers	September, 1997	Sandhu
5664988	Process of polishing a semiconductor wafer having an orientation edge discontinuity shape	September, 1997	Stroupe et al.
5668061	Method of back cutting silicon wafers during a dicing procedure	September, 1997	Herko et al.
5679065	Wafer carrier having carrier ring adapted for uniform chemical-mechanical planarization of semiconductor wafers	October, 1997	Henderson
5681204	Device for detecting a displacement of a blade member of a slicing apparatus	October, 1997	Kawaguchi et al.
5700180	System for real-time control of semiconductor wafer polishing	December, 1997	Sandhu et al.
5702292	Apparatus and method for loading and unloading substrates to a chemical-mechanical planarization machine	December, 1997	Brunelli et al.
5730642	System for real-time control of semiconductor wafer polishing including optical montoring	March, 1998	Sandhu et al.
5738562	Apparatus and method for planar end-point detection during chemical-mechanical polishing	April, 1998	Doan et al.
5747386	Rotary coupling	May, 1998	Moore
5777739	Endpoint detector and method for measuring a change in wafer thickness in chemical-mechanical polishing of semiconductor wafers	July, 1998	Sandhu et al.
5792709	High-speed planarizing apparatus and method for chemical mechanical planarization of semiconductor wafers	August, 1998	Robinson et al.
5795495	Method of chemical mechanical polishing for dielectric layers	August, 1998	Meikle
5798302	Low friction polish-stop stratum for endpointing chemical-mechanical planarization processing of semiconductor wafers	August, 1998	Hudson et al.
5807165	Method of electrochemical mechanical planarization	September, 1998	Uzoh et al.
5830806	Wafer backing member for mechanical and chemical-mechanical planarization of substrates	November, 1998	Hudson et al.
5842909	System for real-time control of semiconductor wafer polishing including heater	December, 1998	Sandhu et al.
5851135	System for real-time control of semiconductor wafer polishing	December, 1998	Sandhu et al.
5855804	Method and apparatus for stopping mechanical and chemical-mechanical planarization of substrates at desired endpoints	January, 1999	Walker
5868896	Chemical-mechanical planarization machine and method for uniformly planarizing semiconductor wafers	February, 1999	Robinson et al.
5879222	Abrasive polishing pad with covalently bonded abrasive particles	March, 1999	Robinson
5882248	Apparatus for separating wafers from polishing pads used in chemical-mechanical planarization of semiconductor wafers	March, 1999	Wright et al.
5893754	Method for chemical-mechanical planarization of stop-on-feature semiconductor wafers	April, 1999	Robinson et al.
5895550	Ultrasonic processing of chemical mechanical polishing slurries	April, 1999	Andreas
5910846	Method and apparatus for detecting the endpoint in chemical-mechanical polishing of semiconductor wafers	June, 1999	Sandhu
5934973	Semiconductor wafer dicing saw	August, 1999	Boucher et al.
5934980	Method of chemical mechanical polishing	August, 1999	Koos et al.
5936733	Endpoint detector and method for measuring a change in wafer thickness in chemical-mechanical polishing of semiconductor wafers	August, 1999	Sandhu et al.
5945347	Apparatus and method for polishing a semiconductor wafer in an overhanging position	August, 1999	Wright
5954912	Rotary coupling	September, 1999	Moore
5967030	Global planarization method and apparatus	October, 1999	Blalock
5972792	Method for chemical-mechanical planarization of a substrate on a fixed-abrasive polishing pad	October, 1999	Hudson
5980363	Under-pad for chemical-mechanical planarization of semiconductor wafers	November, 1999	Meikle et al.
5981396	Method for chemical-mechanical planarization of stop-on-feature semiconductor wafers	November, 1999	Robinson et al.
5994224	IC mechanical planarization process incorporating two slurry compositions for faster material removal times	November, 1999	Sandhu et al.
5997384	Method and apparatus for controlling planarizing characteristics in mechanical and chemical-mechanical planarization of microelectronic substrates	December, 1999	Blalock
6006739	Method for sawing wafers employing multiple indexing techniques for multiple die dimensions	December, 1999	Akram et al.
6007408	Method and apparatus for endpointing mechanical and chemical-mechanical polishing of substrates	December, 1999	Sandhu
6039633	Method and apparatus for mechanical and chemical-mechanical planarization of microelectronic-device substrate assemblies	March, 2000	Chopra
6040245	IC mechanical planarization process incorporating two slurry compositions for faster material removal times	March, 2000	Sandhu et al.
6046111	Method and apparatus for endpointing mechanical and chemical-mechanical planarization of microelectronic substrates	April, 2000	Robinson
6054015	Apparatus for loading and unloading substrates to a chemical-mechanical planarization machine	April, 2000	Brunelli et al.
6057602	Low friction polish-stop stratum for endpointing chemical-mechanical planarization processing of semiconductor wafers	May, 2000	Hudson et al.
6066030	Electroetch and chemical mechanical polishing equipment	May, 2000	Uzoh
6074286	Wafer processing apparatus and method of processing a wafer utilizing a processing slurry	June, 2000	Ball
6083085	Method and apparatus for planarizing microelectronic substrates and conditioning planarizing media	July, 2000	Lankford
6108092	Method and apparatus for detecting the endpoint in chemical-mechanical polishing of semiconductor wafers	August, 2000	Sandhu
6110820	Low scratch density chemical mechanical planarization process	August, 2000	Sandhu et al.
6116988	Method of processing a wafer utilizing a processing slurry	September, 2000	Ball
6120354	Method of chemical mechanical polishing	September, 2000	Koos et al.
6125255	Magnet assembly with inserts and method of manufacturing	September, 2000	Litman
6135856	Apparatus and method for semiconductor planarization	October, 2000	Tjaden et al.
6139402	Method and apparatus for mechanical and chemical-mechanical planarization of microelectronic substrates	October, 2000	Moore
6143123	Chemical-mechanical planarization machine and method for uniformly planarizing semiconductor wafers	November, 2000	Robinson et al.
6143155	Method for simultaneous non-contact electrochemical plating and planarizing of semiconductor wafers using a bipiolar electrode assembly	November, 2000	Adams et al.
6152803	Substrate dicing method	November, 2000	Boucher et al.
6152808	Microelectronic substrate polishing systems, semiconductor wafer polishing systems, methods of polishing microelectronic substrates, and methods of polishing wafers	November, 2000	Moore
6176992	Method and apparatus for electro-chemical mechanical deposition	January, 2001	Talieh
6183345	Polishing apparatus and method	February, 2001	Kamono et al.
6184571	Method and apparatus for endpointing planarization of a microelectronic substrate	February, 2001	Moore
6187681	Method and apparatus for planarization of a substrate	February, 2001	Moore
6190494	Method and apparatus for electrically endpointing a chemical-mechanical planarization process	February, 2001	Dow
6191037	Methods, apparatuses and substrate assembly structures for fabricating microelectronic components using mechanical and chemical-mechanical planarization processes	February, 2001	Robinson
6191864	Method and apparatus for detecting the endpoint in chemical-mechanical polishing of semiconductor wafers	February, 2001	Sandhu
6193588	Method and apparatus for planarizing and cleaning microelectronic substrates	February, 2001	Carlson et al.
6193923	Selective deposition modeling method and apparatus for forming three-dimensional objects and supports	February, 2001	Leyden et al.
6200901	Polishing polymer surfaces on non-porous CMP pads	March, 2001	Hudson et al.
6203404	Chemical mechanical polishing methods	March, 2001	Joslyn et al.
6203407	Method and apparatus for increasing-chemical-polishing selectivity	March, 2001	Robinson
6203413	Apparatus and methods for conditioning polishing pads in mechanical and/or chemical-mechanical planarization of microelectronic-device substrate assemblies	March, 2001	Skrovan
6206754	Endpoint detection apparatus, planarizing machines with endpointing apparatus, and endpointing methods for mechanical or chemical-mechanical planarization of microelectronic substrate assemblies	March, 2001	Moore
6206756	Tungsten chemical-mechanical polishing process using a fixed abrasive polishing pad and a tungsten layer chemical-mechanical polishing solution specifically adapted for chemical-mechanical polishing with a fixed abrasive pad	March, 2001	Chopra et al.
6206769	Method and apparatus for stopping mechanical and chemical mechanical planarization of substrates at desired endpoints	March, 2001	Walker
6208425	Endpoint detector and method for measuring a change in wafer thickness in chemical-mechanical polishing of semiconductor wafers	March, 2001	Sandhu et al.
6210257	Web-format polishing pads and methods for manufacturing and using web-format polishing pads in mechanical and chemical-mechanical planarization of microelectronic substrates	April, 2001	Carlson
6211094	Thickness control method in fabrication of thin-film layers in semiconductor devices	April, 2001	Jun et al.
6213845	Apparatus for in-situ optical endpointing on web-format planarizing machines in mechanical or chemical-mechanical planarization of microelectronic-device substrate assemblies and methods for making and using same	April, 2001	Elledge
6218316	Planarization of non-planar surfaces in device fabrication	April, 2001	Marsh
6224466	Methods of polishing materials, methods of slowing a rate of material removal of a polishing process	May, 2001	Walker et al.
6227955	Carrier heads, planarizing machines and methods for mechanical or chemical-mechanical planarization of microelectronic-device substrate assemblies	May, 2001	Custer et al.
6230069	System and method for controlling the manufacture of discrete parts in semiconductor fabrication using model predictive control	May, 2001	Campbell et al.
6234874	Wafer processing apparatus	May, 2001	Ball
6234877	Method of chemical mechanical polishing	May, 2001	Koos et al.
6234878	Endpoint detection apparatus, planarizing machines with endpointing apparatus, and endpointing methods for mechanical or chemical-mechanical planarization of microelectronic substrate assemblies	May, 2001	Moore
6237483	Global planarization method and apparatus	May, 2001	Blalock
6250994	Methods and apparatuses for mechanical and chemical-mechanical planarization of microelectronic-device substrate assemblies on planarizing pads	June, 2001	Chopra et al.
6251785	Apparatus and method for polishing a semiconductor wafer in an overhanging position	June, 2001	Wright
6261151	System for real-time control of semiconductor wafer polishing	July, 2001	Sandhu et al.
6261163	Web-format planarizing machines and methods for planarizing microelectronic substrate assemblies	July, 2001	Walker et al.
6267650	Apparatus and methods for substantial planarization of solder bumps	July, 2001	Hembree
6273786	Tungsten chemical-mechanical polishing process using a fixed abrasive polishing pad and a tungsten layer chemical-mechanical polishing solution specifically adapted for chemical-mechanical polishing with a fixed abrasive pad	August, 2001	Chopra et al.
6273796	Method and apparatus for planarizing a microelectronic substrate with a tilted planarizing surface	August, 2001	Moore
6276996	Copper chemical-mechanical polishing process using a fixed abrasive polishing pad and a copper layer chemical-mechanical polishing solution specifically adapted for chemical-mechanical polishing with a fixed abrasive pad	August, 2001	Chopra
6287879	Endpoint stabilization for polishing process	September, 2001	Gonzales et al.
6290572	Devices and methods for in-situ control of mechanical or chemical-mechanical planarization of microelectronic-device substrate assemblies	September, 2001	Hofmann
6301006	Endpoint detector and method for measuring a change in wafer thickness	October, 2001	Doan
6306012	Methods and apparatuses for planarizing microelectronic substrate assemblies	October, 2001	Sabde
6306014	Web-format planarizing machines and methods for planarizing microelectronic substrate assemblies	October, 2001	Walker et al.
6306768	Method for planarizing microelectronic substrates having apertures	October, 2001	Klein
6312558	Method and apparatus for planarization of a substrate	November, 2001	Moore
6313038	Method and apparatus for controlling chemical interactions during planarization of microelectronic substrates	November, 2001	Chopra et al.
6319420	Method and apparatus for electrically endpointing a chemical-mechanical planarization process	November, 2001	Dow
6323046	Method and apparatus for endpointing a chemical-mechanical planarization process	November, 2001	Agarwal
6328632	Polishing pads and planarizing machines for mechanical and/or chemical-mechanical planarization of microelectronic substrate assemblies	December, 2001	Chopra
6331488	Planarization process for semiconductor substrates	December, 2001	Doan et al.
6338667	System for real-time control of semiconductor wafer polishing	January, 2002	Sandhu et al.
6350180	Methods for predicting polishing parameters of polishing pads, and methods and machines for planarizing microelectronic substrate assemblies in mechanical or chemical-mechanical planarization	February, 2002	Southwick
6350691	Method and apparatus for planarizing microelectronic substrates and conditioning planarizing media	February, 2002	Lankford
6352466	Method and apparatus for wireless transfer of chemical-mechanical planarization measurements	March, 2002	Moore
6354923	Apparatus for planarizing microelectronic substrates and conditioning planarizing media	March, 2002	Lankford
6354930	Method and apparatus for mechanical and chemical-mechanical planarization of microelectronic substrates	March, 2002	Moore
6358122	Method and apparatus for mechanical and chemical-mechanical planarization of microelectronic substrates with metal compound abrasives	March, 2002	Sabde et al.
6358127	Method and apparatus for planarizing and cleaning microelectronic substrates	March, 2002	Carlson et al.
6358129	Backing members and planarizing machines for mechanical and chemical-mechanical planarization of microelectronic-device substrate assemblies, and methods of making and using such backing members	March, 2002	Dow
6361417	Method and apparatus for supporting a polishing pad during chemical-mechanical planarization of microelectronic substrates	March, 2002	Walker et al.
6362105	Method and apparatus for endpointing planarization of a microelectronic substrate	March, 2002	Moore
6364746	Endpoint detection apparatus, planarizing machines with endpointing apparatus, and endpointing methods for mechanical or chemical-mechanical planarization of microelectronic-substrate assemblies	April, 2002	Moore
6364757	Method and apparatus for mechanical and chemical-mechanical planarization of microelectronic substrates	April, 2002	Moore
6368190	Electrochemical mechanical planarization apparatus and method	April, 2002	Easter et al.
6368193	Method and apparatus for planarizing and cleaning microelectronic substrates	April, 2002	Carlson et al.
6368194	Apparatus for controlling PH during planarization and cleaning of microelectronic substrates	April, 2002	Sharples et al.
6368197	Method and apparatus for supporting and cleaning a polishing pad for chemical-mechanical planarization of microelectronic substrates	April, 2002	Elledge
6376381	Planarizing solutions, planarizing machines, and methods for mechanical and/or chemical-mechanical planarization of microelectronic substrate assemblies	April, 2002	Sabde
6383934	Method and apparatus for chemical-mechanical planarization of microelectronic substrates with selected planarizing liquids	May, 2002	Sabde et al.
6387289	Planarizing machines and methods for mechanical and/or chemical-mechanical planarization of microelectronic-device substrate assemblies	May, 2002	Wright
6395620	Method for forming a planar surface over low density field areas on a semiconductor wafer	May, 2002	Pan et al.
6402884	Planarizing solutions, planarizing machines and methods for mechanical or chemical-mechanical planarization of microelectronic-device substrate assemblies	June, 2002	Robinson et al.
6428386	Planarizing pads, planarizing machines, and methods for mechanical and/or chemical-mechanical planarization of microelectronic-device substrate assemblies	August, 2002	Bartlett
6444481	Method and apparatus for controlling a plating process	September, 2002	Pasadyn
6447369	Planarizing machines and alignment systems for mechanical and/or chemical-mechanical planarization of microelectronic substrates	September, 2002	Moore
6492273	Methods and apparatuses for monitoring and controlling mechanical or chemical-mechanical planarization of microelectronic substrate assemblies	December, 2002	Hofmann et al.
6498101	Planarizing pads, planarizing machines and methods for making and using planarizing pads in mechanical and chemical-mechanical planarization of microelectronic device substrate assemblies	December, 2002	Wang
6505090	Semiconductor device manufacturing method, manufacturing system, support system and recording medium storing program of and data for the manufacture method	January, 2003	Harakawa
6511576	System for planarizing microelectronic substrates having apertures	January, 2003	Klein
6514865	Method of reducing interlayer dielectric thickness variation feeding into a planarization process	February, 2003	Evans
6517412	Method of controlling wafer polishing time using sample-skip algorithm and wafer polishing using the same	February, 2003	Lee et al.
6520834	Methods and apparatuses for analyzing and controlling performance parameters in mechanical and chemical-mechanical planarization of microelectronic substrates	February, 2003	Marshall
6533893	Method and apparatus for chemical-mechanical planarization of microelectronic substrates with selected planarizing liquids	March, 2003	Sabde et al.
6537133	Method for in-situ endpoint detection for chemical mechanical polishing operations	March, 2003	Birang et al.
6546306	Method for adjusting incoming film thickness uniformity such that variations across the film after polishing minimized	April, 2003	Bushman et al.
6547640	Devices and methods for in-situ control of mechanical or chemical-mechanical planarization of microelectronic-device substrate assemblies	April, 2003	Hofmann
6548407	Method and apparatus for controlling chemical interactions during planarization of microelectronic substrates	April, 2003	Chopra et al.
6579799	Method and apparatus for controlling chemical interactions during planarization of microelectronic substrates	June, 2003	Chopra et al.
6586261	Method for determining a preceding wafer group	July, 2003	Ishizuka et al.
6592443	Method and apparatus for forming and using planarizing pads for mechanical and chemical-mechanical planarization of microelectronic substrates	July, 2003	Kramer et al.
6602117	Slurry for use with fixed-abrasive polishing pads in polishing semiconductor device conductive structures that include copper and tungsten and polishing methods	August, 2003	Chopra et al.
6609947	Planarizing machines and control systems for mechanical and/or chemical-mechanical planarization of micro electronic substrates	August, 2003	Moore
6612901	Apparatus for in-situ optical endpointing of web-format planarizing machines in mechanical or chemical-mechanical planarization of microelectronic-device substrate assemblies	September, 2003	Agarwal
6623329	Method and apparatus for supporting a microelectronic substrate relative to a planarization pad	September, 2003	Moore
6628410	Endpoint detector and method for measuring a change in wafer thickness in chemical-mechanical polishing of semiconductor wafers and other microelectronic substrates	September, 2003	Doan
6633084	Semiconductor wafer for improved chemical-mechanical polishing over large area features	October, 2003	Sandhu et al.
6652764	Methods and apparatuses for making and using planarizing pads for mechanical and chemical-mechanical planarization of microelectronic substrates	November, 2003	Blalock
6666749	Apparatus and method for enhanced processing of microelectronic workpieces	December, 2003	Taylor
6794200	Method for determining a preceding wafer, method for determining a measuring wafer, and method for adjusting the number of wafers	September, 2004	Ishizuka et al.
6827629	Method of and apparatus for controlling the chemical mechanical polishing of multiple layers on a substrate	December, 2004	Kim et al.
6857938	Lot-to-lot feed forward CMP process	February, 2005	Smith et al.
7086927	Methods and systems for planarizing workpieces, e.g., microelectronic workpieces	August, 2006	Moore et al.

U.S. Appl. No. 11/471,975, filed Jun. 21, 2006, Moore et al.
Applied Materials, Inc., Mirra Mesa Advanced Integrated CMP, 2 pages, retrieved from the Internet on Jun. 22, 2003, .
Zhang, J. et al., “Automated Process Control of Within-Wafer and Wafer-to-Wafer Uniformity in Oxide CMP,” 6 pages, Mar. 2002, .

Eley, Timothy V.

Perkins Coie LLP

This application is a continuation of U.S. patent application Ser. No. 10/796,257 filed Mar. 9, 2004, now U.S. Pat. No. 7,086,927 issued Aug. 8, 2006, which is incorporated herein by reference in its entirety.

We claim:

1. A method for processing microfeature workpieces, comprising: subjecting a first microfeature workpiece to a first process for a first process time, the first process changing a thickness of the first microfeature workpiece at a first rate; subjecting the first microfeature workpiece to a second process, the second process changing the thickness of the first microfeature workpiece at a second rate that differs from the first rate; determining a thickness change of the first microfeature workpiece attributable to both the first process and the second process; calculating an offset thickness change by offsetting the thickness change by a thickness offset associated with the second process; determining a thickness change factor for the first microfeature workpiece as a ratio of the offset thickness change and the first processing time; determining a target thickness change for a second microfeature workpiece by comparing a second pre-processing thickness of the second microfeature workpiece with a target thickness of the second microfeature workpiece; determining a target processing time as a function of the target thickness change and the thickness change factor; subjecting the second microfeature workpiece to the first process for the target processing time; and subjecting the second microfeature workpiece to the second process.

2. The method of claim 1 wherein the first process and the second process each comprise a planarizing process in which material is removed from a surface of a microfeature workpiece.

3. The method of claim 1 wherein the first process and the second process each comprise a deposition process in which material is deposited on a surface of a microfeature workpiece.

4. The method of claim 3 wherein the first microfeature workpiece is subjected to the second process after it is subjected to the first process.

5. The method of claim 1 wherein the first microfeature workpiece is subjected to a first segment of the second process before it is subjected to the first process and is subjected to a second segment of the second process after it is subjected to the first process.

6. The method of claim 1 wherein determining the thickness change factor comprises dividing the offset thickness change by the first processing time.

7. The method of claim 1 wherein determining the thickness change factor comprises dividing the offset thickness change by the first processing time and determining the target processing time comprises dividing the target thickness change by the thickness change factor.

8. The method of claim 1 wherein determining the target processing time comprises: determining an adjusted target by reducing the target thickness change by the thickness offset; and dividing the adjusted target by the thickness change factor.

9. The method of claim 1 wherein the thickness offset is a constant value for a plurality of microfeature workpieces.

10. The method of claim 1 wherein the thickness offset is a constant value determined as an average thickness change for the second process.

11. The method of claim 1 wherein the thickness offset varies over time.

12. The method of claim 1 wherein the thickness offset varies over time as a function of anticipated change in a rate at which the second process changes the microfeature workpiece thickness.

13. The method of claim 1 wherein determining the thickness change factor further comprises averaging the thickness change factor for the first microfeature workpiece with the thickness change factor determined for at least one previously-processed microfeature workpiece.

14. The method of claim 1 wherein the second process changes the thickness of the first microfeature workpiece at a rate that is independent of the thickness change factor.

15. The method of claim 1 wherein the thickness change of the first microfeature workpiece is determined by measuring a pre-processing thickness of the first microfeature workpiece before subjecting the first microfeature workpiece to the first and second processes; measuring a post-processing thickness of the first microfeature workpiece after subjecting the first microfeature workpiece to the first and second processes; and comparing the pre-processing thickness and the post-processing thickness.

TECHNICAL FIELD

The present invention provides certain improvements in processing microfeature workpieces. The invention has particular utility in connection with planarizing microfeature workpieces, e.g., semiconductor wafers.

BACKGROUND

Mechanical and chemical-mechanical planarizing processes (collectively “CMP processes”) remove material from the surface of semiconductor wafers, field emission displays, or other microfeature workpieces in the production of microelectronic devices and other products. FIG. 1 schematically illustrates a CMP machine 10 with a platen 20 , a carrier assembly 30 , and a planarizing pad 40 . The CMP machine 10 may also have an under-pad 25 attached to an upper surface 22 of the platen 20 and the lower surface of the planarizing pad 40 . A drive assembly 26 rotates the platen 20 (indicated by arrow F), or it reciprocates the platen 20 back and forth (indicated by arrow G). Since the planarizing pad 40 is attached to the under-pad 25 , the planarizing pad 40 moves with the platen 20 during planarization.

The carrier assembly 30 has a head 32 to which a microfeature workpiece 12 may be attached, or the microfeature workpiece 12 may be attached to a resilient pad 34 in the head 32 . The head 32 may be a free-floating wafer carrier, or an actuator assembly 36 may be coupled to the head 32 to impart axial and/or rotational motion to the workpiece 12 (indicated by arrows H and 1 , respectively).

The planarizing pad 40 and a planarizing solution 44 on the pad 40 collectively define a planarizing medium that mechanically and/or chemically removes material from the surface of the workpiece 12 . The planarizing pad 40 can be a soft pad or a hard pad. The planarizing pad 40 can also be a fixed-abrasive planarizing pad in which abrasive particles are fixedly bonded to a suspension material. In fixed-abrasive applications, the planarizing solution 44 is typically a non-abrasive “clean solution” without abrasive particles. In other applications, the planarizing pad 40 can be a non-abrasive pad composed of a polymeric material (e.g., polyurethane), resin, felt, or other suitable materials. The planarizing solutions 44 used with the non-abrasive planarizing pads are typically abrasive slurries with abrasive particles suspended in a liquid. The planarizing solution may be replenished from a planarizing solution supply 46 .

In chemical-mechanical planarization (as opposed to solely mechanical planarization), the planarizing solution 44 will typically chemically interact with the surface of the workpiece 12 to control the removal rate or otherwise optimize the removal of material from the surface of the workpiece. Increasingly, microfeature device circuitry (i.e., trenches, vias, and the like) is being formed from copper. When planarizing a copper layer using a CMP process, the planarizing solution 44 is typically neutral to acidic and includes an oxidizer (e.g., hydrogen peroxide) to oxidize the copper and increase the copper removal rate. One particular slurry useful for polishing a copper layer is disclosed in International Publication Number WO 02/18099, the entirety of which is incorporated herein by reference.

To planarize the workpiece 12 with the CMP machine 10 , the carrier assembly 30 presses the workpiece 12 face-downward against the planarizing medium. More specifically, the carrier assembly 30 generally presses the workpiece 12 against the planarizing solution 44 on a planarizing surface 42 of the planarizing pad 40 , and the platen 20 and/or the carrier assembly 30 move to rub the workpiece 12 against the planarizing surface 42 . As the workpiece 12 rubs against the planarizing surface 42 , material is removed from the face of the workpiece 12 . In some common CMP machines 10 , the pressure of the workpiece 12 against the planarizing medium may be gradually ramped up and/or ramped down over a period of time instead of immediately pressing the workpiece against the planarizing medium with full force and immediately terminating pressure when the planarizing step is complete.

CMP processes should consistently and accurately produce a uniformly planar surface on the workpiece to enable precise fabrication of circuits and photo-patterns. During the construction of transistors, contacts, interconnects and other features, many workpieces develop large “step heights” that create highly topographic surfaces. Such highly topographical surfaces can impair the accuracy of subsequent photolithographic procedures and other processes that are necessary for forming sub-micron features. For example, it is difficult to accurately focus photo patterns to meet tolerances approaching 0.1 micron on topographic surfaces because sub-micron photolithographic equipment generally has a very limited depth of field. Thus, CMP processes are often used to transform a topographical surface into a highly uniform, planar surface at various stages of manufacturing microfeature devices on a workpiece.

In the highly competitive semiconductor industry, it is also desirable to maximize the throughput of CMP processing by producing a planar surface on a substrate as quickly as possible. The throughput of CMP processing is a function, at least in part, of the ability to accurately stop CMP processing at a desired endpoint. In a typical CMP process, the desired endpoint is reached when the surface of the substrate is planar and/or when enough material has been removed from the substrate to form discrete components on the substrate (e.g., shallow trench isolation areas, contacts and damascene lines). Accurately stopping CMP processing at a desired endpoint is important for maintaining a high throughput because the substrate assembly may need to be re-polished if it is “under-planarized,” or components on the substrate may be destroyed if it is “over-polished.” Thus, it is highly desirable to stop CMP processing at the desired endpoint.

In one conventional method for determining the endpoint of CMP processing, the planarizing period of a particular substrate is determined using an estimated polishing rate based upon the polishing rate of identical substrates that were planarized under similar conditions. The estimated planarizing period for a particular substrate, however, may not be accurate because the polishing rate or other variables may change from one substrate to another.

To compensate for changes in planarizing conditions (e.g., degradation of the planarizing pad 40 , variations in the composition of the planarizing solution 44 , or temperature fluctuations), conventional CMP tools predict the estimated planarizing time for the next workpiece 12 using a calculated material removal rate from the preceding workpiece or several preceding workpieces. Typically, this will involve measuring the thickness of the workpiece in a pre-planarizing metrology tool, planarizing the workpiece on the CMP machine 10 , and measuring the thickness of the workpiece again in a post-planarizing metrology tool. Dividing the change in the measured thickness by the time spent planarizing a microfeature workpiece 12 can determine the material removal rate for that particular workpiece. The calculated removal rate may be used as an estimated removal rate for the next workpiece on the assumption that the planarizing conditions will not change too greatly between two sequentially processed workpieces.

To mask statistical variation from one workpiece to another, many CMP machines 10 use an exponentially weighted moving average of material removal rates from a series of microfeature workpieces to predict the material removal rate for the next workpiece. Aspects of such exponentially weighted moving average controllers, among other CMP controllers, are described in some detail in U.S. Pat. No. 6,230,069, the entirety of which is incorporated herein by reference.

Some commercially available CMP machines employ two different types of planarizing pads 40 , each mounted on a separate platen 20 . A first planarizing pad may remove material at a relatively fast rate and a second planarizing pad may be a finishing pad that removes material at a slower rate to yield a highly polished surface. Applied Materials Corporation of California, USA, sells one such CMP machine under the trade name MIRRA MESA. To increase throughput, the MIRRA MESA CMP tool includes two rough planarizing pads and one finishing pad. The material removal rate for the MIRRA MESA machine is calculated in much the same fashion as other conventional CMP machines, i.e., the total change in thickness as a result of processing on the CMP machine is divided by the combined primary planarizing time on the two rough planarizing pads, which tends to be the only planarizing time that is adjusted from one workpiece to the next.

To estimate the planarizing time necessary to planarize an incoming microfeature workpiece, the thickness of the top layer(s) on the incoming workpiece can be measured to determine the amount of material that needs to be removed. The estimated planarizing time may then be calculated using the formula:

$t_{in}=t+\frac{\mathrm{KE}+K_{in}\Delta T_{in}+\mathrm{rI}\left(E^{\prime }\right)}{\mathrm{RR}}$

wherein:

• • t _in is the estimated planarizing time of an incoming workpiece;
  • t is the actual planarizing time of the preceding workpiece;
  • K is an empirically determined constant;
  • E is the difference between the predicted final thickness of the preceding workpiece and the thickness actually measured by the post-planarizing metrology tool;
  • K _in is another empirically determined constant;
  • ΔT _in is the thickness of the material to be removed from the incoming workpiece;
  • r is another empirically determined constant;
  • I(E′) is an integral function (e.g., of the type commonly employed in PID control systems) of the difference between a predicted final thickness and the actually measured thickness for a series of preceding workpieces; and
  • RR is the calculated removal rate. This calculated removal rate may be the removal rate for the immediately preceding workpiece or may be an average, e.g., an exponentially weighted moving average, of a number of preceding workpieces.

The estimated planarizing time calculated in such a fashion can be a reasonably accurate estimate if the amount of material to be removed from the workpiece is relatively large, e.g., several thousand angstroms. With advances in the design of workpieces, the layers of material being removed in the CMP process is decreasing over time, with some CMP processes removing less than 1,000 Å. The conventional techniques outlined above for estimating the planarizing time for a given workpiece are proving less accurate at predicting material removal rate as the amount of material being removed is reduced. This greater variability in calculated removal time, together with the reduced amount of material being removed, can lead to materially under-planarizing or over-planarizing the workpieces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of a planarizing machine in accordance with the prior art.

FIG. 2 is a schematic overview of a planarizing system in accordance with an embodiment of the invention.

FIG. 2A is a schematic overview, similar to FIG. 2, of a planarizing system in accordance with an alternative embodiment of the invention.

FIG. 3 is a schematic cross-sectional view of a main planarizer of the planarizing system shown in FIG. 2.

FIG. 4 is a flow diagram schematically illustrating a planarizing process in accordance with another embodiment of the invention.

DETAILED DESCRIPTION

Various embodiments of the present invention provide methods and apparatus for processing microfeature workpieces. The term “microfeature workpiece” is used throughout to include substrates upon which and/or in which microelectronic devices, micromechanical devices, data storage elements, read/write components, and other features are fabricated. For example, microfeature workpieces can be semiconductor wafers such as silicon or gallium arsenide wafers, glass substrates, insulative substrates, and many other types of materials. The microfeature workpieces typically have submicron features with dimensions of 0.05 microns or greater. Many specific details of the invention are described below with reference to rotary planarizing machines; the present invention can also be practiced using other types of planarizing machines (e.g., web-format planarizing machines). The following description provides specific details of certain embodiments of the invention illustrated in the drawings to provide a thorough understanding of those embodiments. It should be recognized, however, that the present invention can be reflected in additional embodiments and the invention may be practiced without some of the details in the following description.

A. Overview

A microfeature workpiece planarizing system in accordance with one embodiment of the invention includes a carrier assembly, a first planarizer, a second planarizer, a microfeature workpiece transport, and a programmable controller. The first and second planarizers can be first and second planarizing stations of a single tool that are serviced by a single load/unload device, or the first and second planarizers can be separate planarizing tools with separate load/unload devices. The carrier assembly is adapted to hold a microfeature workpiece. The first planarizer includes a first planarizing medium comprising a first planarizing solution and a first planarizing pad, and the second planarizer includes a second planarizing medium comprising a second planarizing solution and a second planarizing pad. The second planarizing medium is different from the first planarizing medium. The microfeature workpiece transport is adapted to transfer a microfeature workpiece from the first planarizer to the second planarizer. The controller is programmed to:

• • receive thickness change information indicative of a change in thickness caused by planarizing a preceding microfeature workpiece in a first process with the first planarizer and in a second process with at least one of the first and second planarizers;
  • determine a modified thickness change by reducing the change in thickness by a thickness offset associated with material removal by the at least one second planarizer;
  • determine a material removal factor for the preceding microfeature workpiece as a function of the modified thickness change and a planarizing time of the preceding microfeature workpiece on the first planarizer;
  • receive initial thickness information indicative of a target thickness change for an incoming microfeature workpiece;
  • estimate a target planarizing time for the first process as a function of the target thickness change and the material removal factor; and
  • cause the first planarizer to planarize the incoming microfeature workpiece for the target planarizing time.

Another embodiment of the invention provides a method for processing a microfeature workpiece in which a first microfeature workpiece is subjected to a first process for a first process time. The first process changes a thickness of the first microfeature workpiece from the first pre-processing thickness at a first rate. The first microfeature workpiece is also subjected to a second process for a second process time, with the second process changing the thickness of the first microfeature workpiece at a second rate that differs from the first rate. A thickness change of the first microfeature workpiece attributable to both the first process and the second process is determined and this thickness change is offset by a thickness offset associated with the second process. A thickness change factor is determined for the first microfeature workpiece as a ratio of the offset thickness change and the first processing time. A second pre-processing thickness of a second microfeature workpiece is measured and a thickness change target is determined for the second microfeature workpiece by comparing the second pre-processing thickness with a target thickness of the second microfeature workpiece. A target processing time for the second microfeature workpiece is determined as a function of the thickness change target and the thickness change factor. The second microfeature workpiece is subjected to the first process for the target processing time and to the second process for a third planarizing time.

For ease of understanding, the following discussion is broken down into two areas of emphasis. The first section discusses various apparatus in accordance with embodiments of the invention. The second section outlines methods in accordance with other embodiments of the invention.

B. Apparatus

FIGS. 2 and 3 schematically illustrate aspects of a planarizing system 100 in accordance with one embodiment of the invention. FIG. 2 is an overview of the planarizing system 100 and FIG. 3 is a cross-sectional view of a planarizer 110 . Many features of the planarizing system 100 and planarizer 110 are shown schematically in these drawings.

The planarizing system 100 of FIG. 2 includes a planarizing machine 102 including a main planarizer 110 and a finishing planarizer 210 . The planarizing machine 102 may also include a second main planarizer 112 , similar to the arrangement of the MIRRA MESA CMP machine noted above. A workpiece transport 230 (shown schematically) may be used to move a microfeature workpiece between a load/unload unit 220 (e.g., a supply cassette or washing station) and the planarizers 110 , 112 , and 210 . The workpiece transport 230 can have a carrier assembly for each of the planarizers 110 , 112 , and 210 such that the planarizers can operate concurrently to simultaneously remove material from a plurality of different workpieces.

The planarizing system 100 of FIG. 2 also includes a pre-planarizing metrology station 250 a and a post-planarizing metrology station 250 b . Suitable metrology systems adapted to measure the thicknesses of microfeature workpieces are commercially available from a variety of sources. Although FIG. 2 illustrates two separate metrology stations 250 a and 250 b , a single metrology station could instead measure both the pre-planarizing thickness and the post-planarizing thickness of the microfeature workpieces.

The planarizing system 100 of FIG. 2 also includes a control system 170 comprising a controller 180 . The controller 180 may include a programmable processor 182 and a computer-readable program 184 that causes the controller 180 to control operation of other elements of the planarizing system 100 . The controller 180 may take the form of a single computer or a plurality of computers arranged in a network.

In the illustrated embodiment, the controller 180 is operatively connected to the pre- and post-planarizing metrology stations 250 a - b and is adapted to receive metrology information from the metrology stations 250 a - b . The metrology information is indicative of a change in thickness of the workpiece resulting from planarizing. In one embodiment, the metrology information received by the controller 180 may be the actual thickness change. In another embodiment, the metrology information includes a pre-planarizing thickness of a microfeature workpiece or layer(s) on a microfeature workpiece as measured by the pre-planarizing metrology station 250 a and/or a post-planarizing thickness for the microfeature workpiece as measured by the post-planarizing metrology station 250 b . The metrology stations 250 may provide thickness data for a particular workpiece as a single number, which may represent an average thickness across the workpiece surface, or as a set of data representing a plurality of thickness measurements from different locations on the workpiece surface.

The controller 180 may also be operatively coupled to one or more of the first main planarizer 110 , the second main planarizer 112 , and the finishing planarizer 210 . In some embodiments, the controller 180 need not be operatively coupled to the finishing planarizer 210 . In many anticipated embodiments, the controller 180 is operatively connected to at least one, if not both, of the first and second main planarizers 110 and 112 .

FIG. 2A schematically illustrates a planarizing system 101 in accordance with an alternative embodiment of the invention. Most of the elements of the planarizing system 101 may be directly analogous to elements of the planarizing system 100 of FIG. 2 and like reference numbers are used in FIGS. 2 and 2A to identify like elements. One difference between the planarizing systems 100 and 101 is that the planarizing machine 102 of FIG. 2 includes two main planarizers 110 and 112 and a single finishing planarizer 210 , but the planarizing machine 103 of FIG. 2A includes a single main planarizer 110 and first and second finishing planarizers 210 and 212 , respectively.

FIG. 3 shows the first planarizer 110 of the planarizing machine 102 in greater detail. In the illustrated embodiment, the first planarizer 110 includes a table or platen 120 coupled to a drive mechanism 121 that rotates the platen 120 . The platen 120 can include a support surface 124 . The planarizing machine 102 can also include a carrier assembly 130 having a workpiece holder 132 or head coupled to an actuator mechanism 136 . The workpiece holder 132 holds and controls a workpiece 12 during a planarizing cycle. The workpiece holder 132 can include a plurality of nozzles 133 through which a planarizing solution 135 can flow during a planarizing cycle. The carrier assembly 130 can be substantially the same as the carrier assembly 30 described above with reference to FIG. 1.

The planarizing machine 102 can also include a planarizing medium 150 comprising the planarizing solution 135 and a planarizing pad 140 having a planarizing body 142 . The planarizing body 142 can be formed of an abrasive or non-abrasive material having a planarizing surface 146 . For example, an abrasive planarizing body 142 can have a resin matrix (e.g., a polyurethane resin) and a plurality of abrasive particles fixedly attached to the resin matrix. Suitable abrasive planarizing bodies 142 are disclosed in U.S. Pat. Nos. 5,645,471; 5,879,222; 5,624,303; 6,039,633; and 6,139,402, each of which is incorporated herein in its entirety by reference.

The controller 180 of the control system 170 may be operatively coupled to the drive mechanism 121 of the platen 120 and to the actuator mechanism 136 of the carrier assembly 130 , as shown. The controller 180 may control a parameter of the drive mechanism 121 and/or the actuator mechanism 136 , e.g., by starting and stopping the drive mechanism in accordance with a calculated polishing time. In one embodiment, the controller 180 calculates this polishing time in accordance with one of the methods outlined below. The program 184 can be contained on a computer-readable medium stored in the controller 180 .

Although FIG. 3 illustrates only the first main planarizer 110 , the structure and operation of the second main planarizer 112 (FIG. 2), the finishing planarizer 210 , and the second finishing planarizer 212 (FIG. 2A) may be similar to that of the main planarizer 110 shown in FIG. 3. The difference between the finishing planarizers ( 210 and 212 ) and the main planarizers ( 110 and 112 ) is that the finishing planarizers typically perform a less aggressive polishing process than the main planarizers. For example, the finishing planarizer 210 of FIG. 2 typically uses only mild abrasives and/or less downforce to smooth the finished surface by reducing or eliminating surface asparities caused by the more aggressive main planarizers 110 and 112 . The finishing planarizer accordingly often has a different planarizing pad 140 or a different planarizing solution 135 than the main planarizers 110 and 112 . This allows the removal rate of the finishing planarizer 210 to be independent from the removal rate of the main planarizer so that the main planarizers 110 and 112 have a higher removal rate and the finishing planarizer 210 provides a more polished surface.

C. Methods of Controlling Planarizing

As noted above, other embodiments of the invention provide methods of processing a microfeature workpiece 12 . In the following discussion, reference is made to the planarizing system 100 illustrated in FIGS. 2 and 3. It should be understood, though, that reference to this particular planarizing system is solely for purposes of illustration and that the methods outlined below are not limited to any particular planarizing system shown in the drawings or discussed in detail above.

FIG. 4 schematically illustrates a microfeature workpiece processing method 300 in accordance with one embodiment of the invention. At the outset, a material removal factor R may be initialized at a predetermined value R ₀ in a process 302 . As explained below, this material removal factor R may comprise an anticipated material removal rate for planarizing on the main planarizer 110 . The initial value R ₀ may be determined empirically for the type of microfeature workpiece 12 being processed and the nominal processing conditions (e.g., temperature, planarizing media characteristics, and downforce of the carrier 130 ). Alternatively, the initial value R ₀ may comprise a material removal factor calculated for the same system at the end of a previous batch of microfeature workpieces 12 .

In the particular method 300 shown in FIG. 4, a batch of microfeature workpieces 12 may be processed sequentially. If so desired, the number n of the workpiece within the batch of workpieces may be initialized at a value of one in process 304 .

The initial thickness of the first microfeature workpiece 12 in the batch of workpieces may be measured with the pre-planarizing metrology station 250 a in process 310 . As noted, this thickness measurement may be provided to the controller 180 as a single average number or as a set of data reflecting a series of measurements from different locations on a surface of the microfeature workpiece 12 . As is known in the art, the “thickness” measurements by the metrology station 250 a may be a measurement of the total thickness of the microfeature workpiece 12 or a thickness of select layer(s) on the microfeature workpiece 12 . Alternatively, the thickness may be measured as an offset from a known plane within the metrology system 250 a.

The controller 180 may then determine a target thickness change for the incoming first microfeature workpiece 12 in process 320 , which may include comparing the initial thickness measurement for the workpiece from process 310 to a target thickness for the microfeature workpiece 12 . For example, a nominal target thickness for all of the microfeature workpieces 12 may be programmed in the controller 180 and subtracted from the initial thickness measured in process 310 . In one particular embodiment, the target thickness change (ΔT _in ) may be reduced by a predetermined thickness offset T _offset , as discussed below. The resultant reduced target thickness change (ΔT _reduced =ΔT _in −T _offset ) may more accurately reflect the desired thickness change resulting from planarizing by the main planarizer 110 (or planarizers 110 and 112 ).

In process 330 , the controller 180 may calculate a target planarizing time t _in for the incoming microfeature workpiece 12 as a function of the target thickness change ΔT _in or ΔT _reduced and the material removal factor R. If the material removal factor R is correlated to a material removal rate (e.g., Å/sec), the target planarizing time t _in may comprise the target thickness change ΔT _in or ΔT _reduced divided by this material removal rate R. If the material removal rate is instead determined as a function of the time necessary to remove a given thickness (e.g., sec/ÅÅ), the target thickness change ΔT _in or ΔT _reduced may be multiplied by this material removal factor R.

The controller 180 may then control operation of the main planarizer 110 to planarize the microfeature workpiece 12 for the target planarizing time t _in . The controller 180 may terminate planarizing of the microfeature workpiece 12 at the end of the target planarizing time t _in by sending a stop signal to the actuator mechanism 136 of the carrier assembly 130 and/or to the drive mechanism 121 of the platen 120 .

As noted previously, planarizing the microfeature workpiece 112 generally comprises pressing the workpiece 112 against the planarizing medium 150 in a controlled manner. In one particular embodiment of the invention, the pressure is gradually ramped up and/or ramped down instead of suddenly applied at the beginning of the planarizing cycle and suddenly ended when the stop signal is generated. The controller 180 or another aspect of the planarizing system 100 in this embodiment may ramp up the pressure before the target planarizing time t _in begins and ramp down the pressure at the end of the target planarizing time t _in . Other ramp-up and ramp-down processes may employ a substantially constant pressure, but allow stabilization of other control parameters (e.g., temperature) before and/or after the target planarizing time t _in . The ramp-up and ramp-down processes may be substantially the same from one workpiece to the next. This ramp-up and ramp-down time, which may be considered a secondary planarizing on the main planarizer 110 , typically will remove material appreciably more slowly than in the main planarizing process 340 conducted at the full pressure for the target planarizing time t _in .

In addition to, or instead of, such ramp-up and ramp-down processes, the planarizing process may include a variety of other secondary planarizing processes. For example, microfeature workpieces 12 may be subjected to a main planarizing step and a separate edge planarizing step that is targeted to polish a peripheral region of the microfeature workpieces 12 . In one embodiment, such edge planarizing may be considered a secondary planarizing step carried out on the main planarizer 110 and the edge planarizing time is not included in the target planarizing time t _in . In an alternative embodiment, the edge planarizing process may be considered part of the main planarizing process 340 and the target planarizing time t _in may include the time spent on the main planarizer both in generally planarizing the microfeature workpiece 12 and in the edge planarizing process.

In some embodiments, the planarizing machine 102 includes both a first main planarizer 110 and a second main planarizer 112 . If each microfeature workpiece 12 is subjected to a main planarizing process only on one of these planarizers 110 and 112 , each microfeature workpiece 12 may remain on the main planarizer 110 or 112 for the full target planarizing time t _in . In other embodiments, each microfeature workpiece 12 may be planarized by both of the main planarizers 110 and 112 in sequence before being planarized by the finishing planarizer 210 . In such an embodiment, the target planarizing time t _in may be allocated between the two main planarizers 110 and 112 in any desired fashion, e.g., by planarizing microfeature workpieces 12 for an equal time on each of the main planarizers 110 and 112 . If microfeature workpieces 12 are to be planarized on both of the main planarizers 110 and 112 , a secondary planarizing may be employed to ramp up and ramp down the applied planarizing pressure on each of the main planarizers 110 and 112 .

After being planarized on the main planarizer(s) in the first planarizing process 340 , the microfeature workpiece 12 may be planarized on the finishing planarizer 210 in a second planarizing process 350 . In one embodiment, the planarizing time on the finishing planarizer 210 may remain substantially constant over the entire run of the batch of microfeature workpieces 12 . In other embodiments, this time may be varied from one microfeature workpiece to the next in accordance with a predetermined profile. If the planarizing machine includes a second finishing planarizer 212 (FIG. 2A), the time of the second planarizing process 350 may be divided between the two finishing planarizers 210 and 212 . In select embodiments, the second planarizing process 350 may include not only planarizing on the finishing planarizer(s) 210 and/or 212 , but also the secondary planarizing reflected by the ramp-up and ramp-down procedures noted above. In one embodiment, the second planarizing process 350 may be considered to include all planarizing, on any planarizer ( 110 , 112 , 210 , and/or 212 ), other than that reflected in the main planarizing process 340 .

After the first and second planarizing processes 340 and 350 , the thickness of the planarized workpiece may be measured in a post-planarizing thickness measuring process 360 . This post-planarizing thickness may be compared to the pre-planarizing thickness measured in process 310 to determine the actual change in thickness ΔT _actual for the workpiece in process 370 . This actual change in thickness ΔT _actual may be determined, for example, by subtracting the post-planarizing thickness measurement from the pre-planarizing thickness measurement.

The actual thickness change ΔT _actual may be used to calculate the material removal factor R in process 380 . This material removal factor R may comprise a ratio of the actual thickness change ΔT _actual to the planarizing time t _in on the main planarizer 110 (or planarizers 110 and 112 ). For example, the material removal factor R may be calculated as a material removal rate by dividing the actual thickness change ΔT _actual by the planarizing time on the main planarizer 110 . Alternatively, the material removal factor R may be determined as a length of time necessary to remove a given thickness by dividing the planarizing time t _in by the actual thickness change ΔT _actual .

In at least one embodiment of the invention, the material removal factor R is adjusted by a thickness offset T _offset corresponding to the amount of material removed from the workpiece in the second planarizing process 350 . In particular, the actual thickness change ΔT _actual may be reduced by the thickness offset T _offset to provide an adjusted thickness change ΔT _adjusted before calculating the material removal factor R as a ratio of the adjusted thickness change ΔT _adjusted and the planarizing time t _in . For example, if the material removal factor R _main is an approximation of a material removal rate for the main planarizing stage, it may be calculated as follows:
R _main =(Δ T _actual −T _offset )/ t _in

The value of the thickness offset T _offset to compensate for material removed by the finishing planarizer may be determined empirically or in any other suitable fashion. In one embodiment, the thickness offset T _offset may remain constant over a significant period of time, e.g., over a plurality of planarizing cycles. For example, the thickness offset T _offset may be determined empirically as an average thickness removed from a number of like microfeature workpieces 12 by the second planarizing process 350 . In other embodiments, the thickness offset T _offset may vary over time. For example, the thickness offset T _offset may be determined as a function of anticipated change in the material removal rate in the second planarizing process 350 . This anticipated change also may be determined empirically and may be used to compensate for estimated changes in the material removal rate in the second planarizing process 350 , e.g., as the planarizing medium of the finishing planarizer 210 or second finishing planarizer 212 (FIG. 2A) changes with use.

The workpiece counter n may be indexed by one in process 390 and processes 310 - 390 may be performed on the next microfeature workpiece 12 . This series of processes may be repeated until all of the microfeature workpieces 12 in the batch of workpieces have been planarized.

The target planarizing time t _in for each microfeature workpiece 12 may be calculated in process 330 as a function of the material removal rate R determined in process 380 for at least one preceding microfeature workpiece 12 . In one embodiment, the material removal factor R is calculated in process 380 as an average of the material removal factor for two or more sequential workpieces 12 , e.g., using an exponential weighted moving average.

Embodiments of the invention provide material improvements in the precision with which the planarizing time for a given microfeature workpiece 12 may be estimated. As noted above, the precision of this estimate decreases significantly using conventional techniques when the thickness of the material to be removed is relatively thin, e.g., less than 1,000 Å. Embodiments of the present invention, however, more effectively isolate the effects of the finishing planarizer 210 (and second finishing planarizer 212 , if employed) on the estimated polishing time for main planarizers 110 and 112 by factoring in the thickness offset T _offset associated with the second planarizing process 350 .

To illustrate advantages of embodiments of the invention, consider an idealized example in which a first microfeature workpiece 12 is planarized on the main planarizers 110 and 112 for a total of 10 seconds. The actual thickness change ΔT _actual is determined to be about 600 Å.

Scenario 1 (employing conventional control processes): In a conventional control algorithm, the material removal rate would be calculated as the actual thickness change divided by the planarizing time, i.e., 600 Å/10 sec=60 Å/sec. Assume a second microfeature workpiece 12 is determined to require removal of 900 Å. Dividing 900 Å by the calculated removal rate of 60 Å/sec estimates a target planarizing time of 15 seconds. After planarizing the second microfeature workpiece on the planarizers 110 , 112 , and 210 , the actual thickness change ΔT _actual is determined to be only about 750 Å, leaving the second microfeature workpiece 12 significantly underplanarized. The removal rate for the second microfeature workpiece 12 would be calculated as 50 Å/sec (750 Å/15 sec). The planarizing time for next microfeature workpiece 12 may be estimated using either this 50 Å/sec rate or an average removal rate for the first and second microfeature workpieces 12 , e.g., 55 Å/sec.

Scenario 2 (employing an embodiment of the invention): Assume that the second planarizing process 350 (including ramp-up and ramp-down processes on the main planarizer 110 and planarizing on the finishing planarizer 210 ) was monitored over time and found to remove about 300 Å on average. Using this 300 Å average as the thickness offset T _offset the adjusted thickness change ΔT _adjusted for the first microfeature workpiece 12 can be calculated as 600 Å−300 Å=300 Å. Dividing the adjusted thickness change ΔT _adjusted by the 10-second planarizing time yields a material removal rate R of 30 Å/sec. In accordance with an embodiment of the invention, the thickness offset T _offset may be subtracted from the target thickness change ΔT _in of 900 Å for the second microfeature workpiece to yield a reduced target thickness change ΔT _seduced of 900 Å−300 Å=600 Å. Dividing this reduced target thickness change ΔT _reduced by the material removal rate R yields a target planarizing time t _in of 20 seconds. The actual thickness change ΔT _actual of the second microfeature workpiece 12 after completing the planarizing cycle on the three planarizers 110 , 112 and 210 is assumed to be 890 Å, a nominal deviation from the 900 Å target thickness change ΔT _in . Dividing adjusted thickness change ΔT _adjusted for the second microfeature workpiece 12 (890 Å−300 Å=590 Å) by the 20-second combined planarizing time t _in on the main planarizers yields a material removal rate R of 29.5 Å/sec.

Comparing these two scenarios, the planarizing time necessary to remove the desired thickness of material from the second microfeature workpiece 12 is estimated significantly more accurately in Scenario 2 employing an embodiment of the invention than in the more conventional Scenario 1. Whereas the second planarized microfeature workpiece 12 in Scenario 2 likely would fall within commercially acceptable tolerances, the second planarized workpiece in Scenario 1 likely would be rejected if planarizing relied solely on the estimated planarizing time. Scenario 2 is also more precise than Scenario 1 in calculating the pertinent material removal rate, with the anticipated standard deviation in Scenario 2 being substantially less than the standard deviation in Scenario 1.

The preceding discussion focuses on planarizing microfeature workpieces 12 , but aspects of the present invention may also be useful in other contexts. For instance, a method analogous to method 300 of FIG. 4 may be used to control a deposition process wherein microfeature workpieces are subjected to two deposition processes with different rates of material deposition. In a microfeature workpiece deposition process employing both chemical vapor deposition (CVD) and atomic layer deposition (ALD), for example, one or more parameters of the CVD process may be controlled on the basis of a deposition rate calculated using a thickness offset T _offset correlated to the amount of material deposited via ALD.

In general, the terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification unless the above-detailed description explicitly defines such terms. While certain aspects of the invention are presented below in certain claim forms, the inventors contemplate various aspects of the invention in any number of claim forms. Accordingly, the inventors reserve the right to add additional claims after filing the application to pursue such additional claim forms for other aspects of the invention.