US5964643A — Apparatus and method for in-situ monitoring of ch…

Claim 1

Independent Claim 78 words

A substrate polishing system comprising: a platen which during processing holds a polishing pad; a polishing head which during processing holds the substrate against the polishing pad on the platen; an interferometer capable of generating a collimated light beam which during processing is directed at and impinges on a side of said substrate that is being polished, said interferometer generating an interference signal; and a data processor programmed to compute a measure of uniformity from said interference signal.

Claim 2

Dependent Claim 78 words

A substrate polishing system comprising: a platen which during processing holds a polishing pad; a polishing head which during processing holds the substrate against the polishing pad on the platen; an interferometer capable of generating a collimated light beam which during processing is directed at and impinges on a side of said substrate that is being polished, said interferometer generating an interference signal; and a data processor programmed to compute a measure of uniformity from said interference signal.

Claim 3

Dependent Claim 18 words

The polishing system of claim 1 wherein said polishing head is rotatable so that it rotates during processing.

Claim 4

Dependent Claim 17 words

The polishing system of claim 2 wherein said platen is rotatable so that it rotates during processing.

Claim 5

Dependent Claim 13 words

The polishing system of claim 3 wherein said interferometer is a laser interferometer.

Claim 6

Dependent Claim 32 words

The polishing system of claim 3 wherein said data processor is further programmed to: extract feature information from said interference signal; and compute said measure of uniformity from said extracted feature information.

Claim 7

Dependent Claim 41 words

The polishing system of claim 5 wherein said data processor is further programmed to: compare said measure of uniformity to a reference; and generate an alert when said measure of uniformity diverges from the reference by more than a predetermined amount.

Claim 8

Dependent Claim 45 words

The polishing system of claim 6 wherein said interference signal includes a low frequency component and wherein said data processor is programmed to extract feature information by: measuring a first characteristic of said low frequency component; and deriving said extracted information from said first characteristic.

Claim 9

Dependent Claim 47 words

The polishing system of claim 7 wherein said interference signal includes a high frequency component and wherein said data processor is programmed to extract feature information by: measuring a second characteristic of said high frequency signal; and deriving said extracted information from said first and second characteristics.

Claim 10

Dependent Claim 56 words

The polishing system of claim 8 wherein said first characteristic is an amplitude of said high frequency signal and said second characteristic is an amplitude of said low frequency signal, and wherein said data processor is programmed to derive said extracted information by computing a ratio of the amplitudes of said high and low frequency signals.

Claim 11

Independent Claim 109 words

An apparatus for polishing a substrate, said apparatus comprising: a platen which during processing holds a polishing pad, said platen including a passage therethrough; a polishing head which during processing holds the substrate against the polishing pad on the platen; and an interferometer capable of generating a collimated light beam, said interferometer arranged to direct said light beam at least during part of the polishing operation through said passage so that it impinges on said substrate; a window aligned with said passage and through which the light beam passes on its way to the substrate, said window having a diffuse surface receiving the arriving light beam from the interferometer.

Claim 12

Independent Claim 109 words

An apparatus for polishing a substrate, said apparatus comprising: a platen which during processing holds a polishing pad, said platen including a passage therethrough; a polishing head which during processing holds the substrate against the polishing pad on the platen; and an interferometer capable of generating a collimated light beam, said interferometer arranged to direct said light beam at least during part of the polishing operation through said passage so that it impinges on said substrate; a window aligned with said passage and through which the light beam passes on its way to the substrate, said window having a diffuse surface receiving the arriving light beam from the interferometer.

Claim 13

Dependent Claim 30 words

The apparatus of claim 10 further comprising the polishing pad mounted on said platen and wherein said window is formed in said polishing pad and is aligned with said passage.

Claim 14

Dependent Claim 156 words

A substrate polishing system comprising: a platen which during a polishing operation holds a polishing pad; a polishing head which during the polishing operation holds the substrate against the polishing pad on the platen; an interferometer capable of generating a collimated light beam which during the polishing operation is directed at and impinges on a side of said substrate that is being polished, said interferometer generating an interference signal, wherein the interference signal at least for some part of the polishing operation has an amplitude that is cyclical in nature; a display device; and a processor which during the polishing operation receives the interference signal and is programmed to generate therefrom a characterizing waveform which characterizes the polishing operation, said processor further programmed to display the characterizing waveform on the display device for an operator to see, said characterizing waveform presenting data for a period of time that extends over multiple cycles of the interference signal.

Claim 15

Dependent Claim 156 words

A substrate polishing system comprising: a platen which during a polishing operation holds a polishing pad; a polishing head which during the polishing operation holds the substrate against the polishing pad on the platen; an interferometer capable of generating a collimated light beam which during the polishing operation is directed at and impinges on a side of said substrate that is being polished, said interferometer generating an interference signal, wherein the interference signal at least for some part of the polishing operation has an amplitude that is cyclical in nature; a display device; and a processor which during the polishing operation receives the interference signal and is programmed to generate therefrom a characterizing waveform which characterizes the polishing operation, said processor further programmed to display the characterizing waveform on the display device for an operator to see, said characterizing waveform presenting data for a period of time that extends over multiple cycles of the interference signal.

Claim 16

Dependent Claim 18 words

The polishing system of claim 12 wherein said polishing head is rotatable so that it rotates during processing.

Claim 17

Dependent Claim 17 words

The polishing system of claim 13 wherein said platen is rotatable so that it rotates during processing.

Claim 18

Dependent Claim 13 words

The polishing system of claim 14 wherein said interferometer is a laser interferometer.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2002-10-11	2003-04-12	2003-10-12	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2006-10-11	2007-04-12	2007-10-12	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2010-10-11	2011-04-12	2011-10-12	$7700.00	Window Closed / Lapsed

Apparatus and method for in-situ monitoring of chemical mechanical polishing operations

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