Polishing with measurement prior to deposition of outer layer

Patent metadata

Field	Value
Publication number	US-2016284615-A1
Application number	US-201615173584-A
Country	US
Kind code	A1
Filing date	Jun 3, 2016
Priority date	Jul 16, 2014
Publication date	Sep 29, 2016
Grant date	—

Abstract

A method of controlling polishing includes storing a base measurement, the base measurement being a measurement of a substrate after deposition of at least one layer overlying a semiconductor wafer and before deposition of an outer layer over the at least one layer, after deposition of the outer layer over the at least one layer and during polishing of the outer layer on substrate, receiving a sequence of raw measurements of the substrate from an in-situ monitoring system, normalizing each raw measurement in the sequence of raw measurement to generate a sequence of normalized measurements using the raw measurement and the base measurement, and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on at least the sequence of normalized measurements.

First claim

1 - 20 . (canceled)

21 . A computer program product, encoded on one or more non-transitory computer storage media, comprising instructions that when executed by one or more computers cause the one or more computers to perform operations comprising:
storing a base measurement, the base measurement being a measurement of a substrate after deposition of at least one layer overlying a semiconductor wafer and before deposition of an outer layer over the at least one layer; after deposition of the outer layer over the at least one layer and during polishing of the outer layer on substrate, receiving a sequence of raw measurements of the substrate from an in-situ monitoring system; normalizing each raw measurement in the sequence of raw measurement to generate a sequence of normalized measurements using the raw measurement and the base measurement; and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on at least the sequence of normalized measurements.

22 . The computer program product of claim 21 , wherein the raw measurement comprises a raw spectrum and the base measurement comprises a base spectrum received from an optical monitoring system.

23 . The computer program product of claim 21 , wherein the raw measurement comprises a raw eddy current measurement and the base measurement comprises a base eddy current value from an eddy current monitoring system.

23 . The computer program product of claim 21 , wherein normalizing includes a division operation in which the raw measurement is in the numerator and the base measurement is in the denominator.

24 . The computer program product of claim 23 , wherein the division operation comprises calculating

R
=

A
-

D
A

B
-

D
B

where R is the normalized measurement, A is the raw measurement, B is the base measurement and DA and DB are measurements made by the in-situ monitoring system when no substrate is being measured by the in-situ monitoring system.

25 . The computer program product of claim 21 , wherein the base measurement comprises a measurement of the substrate after deposition of the at least one layer but before an etching process of the at least one layer.

26 . The computer program product of claim 21 , wherein the base measurement comprises a measurement of the substrate after an etching process of the at least one layer but before deposition of an intermediate layer over the at least one layer.

27 . The computer program product of claim 21 , wherein the base measurement comprises a measurement of the substrate after deposition of an intermediate layer over the at least one layer but before depositing the outer layer to undergo polishing.

28 . The computer program product of claim 21 , wherein the operations further comprise generating a sequence of values from the sequence of measurements, fitting a function to the sequence of values, determining a projected time at which the function reaches a target value, and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on the projected time.

29 . A method of fabricating a substrate comprising:
depositing a plurality of layers on a substrate, the plurality of layers including at least one underlying layer and at least one outer layer; making a base measurement of a substrate, the base measurement being a measurement of a substrate after deposition of the at least one underlying layer and before deposition of the outer layer; after depositing the overlying layer, polishing the overlying layer; during polishing of the overlying conductive layer, making a sequence of raw measurements of the substrate with an in-situ monitoring system; normalizing each raw measurement in the sequence of raw measurements to generate a sequence of normalized measurements using the raw measurement and the base measurement; and determining at least one of a polishing endpoint or an adjustment for a polishing rate based on at least one normalized predetermined spectrum from the sequence of normalized measurements.

30 . The method of claim 29 , wherein the at least one underlying layer comprises a dielectric layer and the outer layer comprises a conductive layer.

31 . The method of claim 30 , wherein the sequence of raw measurements comprises a sequence of eddy current values measured by an eddy current monitoring system and the base measurement comprises a base eddy current value.

32 . The method of claim 29 , wherein the at least one underlying layer comprises a conductive layer and the outer layer comprises a dielectric layer.

33 . The method of claim 32 , wherein the sequence of raw measurements comprises a sequence of spectra measured by an optical monitoring system and the base measurement comprises a base spectrum.

34 . The method of claim 29 , wherein the base measurement is made after deposition of the at least one layer but before an etching process of the at least one layer.

35 . The method of claim 29 , wherein the base measurement is made after an etching process of the at least one layer but before deposition of an intermediate layer over the at least one layer.

36 . The method of claim 29 , wherein the base measurement is made after deposition of an intermediate layer over the at least one layer but before depositing the outer layer to undergo polishing.

37 . An integrated circuit fabrication system, comprising:
a deposition system configured to receive a substrate, and deposit a stack of layers on a substrate, the stack of layers including an outer layer to undergo polishing and at least one layer underlying the outer layer; a metrology system configured to generate a measurement of the substrate after deposition of the at least one layer and before deposition of the outer layer; and a polishing system configured to receive the substrate after deposition of the outer layer on the substrate and polish the outer layer, wherein the polishing system includes an in-situ monitoring system and a controller configured to perform operations comprising:
receiving the measurement from the metrology system and storing the measurement as a base measurement,
receiving a sequence of raw measurements of the substrate during polishing from the in-situ monitoring system,
normalizing each raw measurement in the sequence of raw measurements to generate a sequence of normalized measurements using the raw measurement and the base measurement, and
determining at least one of a polishing endpoint or an adjustment for a polishing rate based on at least one normalized predetermined measurement from the sequence of normalized measurement.

38 . The system of claim 37 , wherein the in-situ monitoring system comprises an optical monitoring system and the metrology system comprises an optical metrology system.

39 . The system of claim 37 , wherein the in-situ monitoring system comprises an eddy current monitoring system and the metrology system comprises an eddy current metrology system.

40 . The system of claim 37 , wherein the metrolo

Assignees

• Applied Materials Inc

Inventors

• Kitajima Tomohiko
• David Jeffrey Drue
• Qian Jun
• Sekine Taketo
• Leung Garlen C
• Huey Sidney P

Classifications

• H10P95/062

  involving a dielectric removal step · CPC title

• H10P74/277

  Circuits for electrically characterising or monitoring manufacturing processes, e.g. circuits in tested chips or circuits in testing wafers · CPC title

• H10P74/207

  Electrical properties, e.g. testing or measuring of resistance, deep levels or capacitance-voltage characteristics · CPC title

• H10P74/23

  characterised by multiple measurements, corrections, marking or sorting processes · CPC title

• H10P72/0604

  Process monitoring, e.g. flow or thickness monitoring · CPC title