US-12617057-B2 - Method of creating correlation relational formula for determining polishing condition, method of determining polishing condition, and semiconductor wafer manufacturing method

US12617057B2US 12617057 B2US12617057 B2US 12617057B2US-12617057-B2

Abstract

A method of creating a correlation relational formula for determining a polishing condition, the method including polishing semiconductor wafers under a plurality of polishing conditions including a plurality of polishing parameters, and acquiring, by actual measurement, in-plane polishing amount distribution information on the semiconductor wafers in polishing under the plurality of polishing conditions; polishing semiconductor wafers under a plurality of polishing conditions including a plurality of polishing parameters, and acquiring, by actual measurement, in-plane temperature distribution information during semiconductor wafer polishing in polishing under the plurality of polishing conditions, or creating in-plane temperature distribution information during semiconductor wafer polishing under polishing conditions including a plurality of polishing parameters by heat transfer analysis, and correlating relational formulas between a semiconductor wafer in-plane temperature distribution parameter and a plurality of polishing parameters.

Inventors

Yuki Nakano

Assignees

SUMCO CORPORATION

Dates

Publication Date: 20260505
Application Date: 20220228
Priority Date: 20210510

Claims (10)

1 . A method of creating a correlation relational formula for determining a polishing condition, the method comprising: polishing semiconductor wafers under a plurality of polishing conditions including a plurality of polishing parameters, and acquiring, by actual measurement, in-plane polishing amount distribution information on the semiconductor wafers in polishing under the plurality of polishing conditions; polishing semiconductor wafers under a plurality of polishing conditions including a plurality of polishing parameters, and acquiring, by actual measurement, in-plane temperature distribution information during semiconductor wafer polishing in polishing under the plurality of polishing conditions, or creating in-plane temperature distribution information during semiconductor wafer polishing under polishing conditions including a plurality of polishing parameters by heat transfer analysis; creating correlation relational formula 1 between a semiconductor wafer in-plane temperature distribution parameter and a plurality of polishing parameters on the basis of the in-plane temperature distribution information during polishing; creating correlation relational formula 2 between a semiconductor wafer in-plane polishing amount distribution parameter and a plurality of polishing parameters on the basis of the in-plane polishing amount distribution information; and creating correlation relational formula 3 between a semiconductor wafer in-plane polishing amount distribution parameter and a plurality of polishing parameters on the basis of the correlation relational formula 1 and the correlation relational formula 2, wherein the correlation relational formula 3 is a correlation relational formula to be used to determine a polishing condition in semiconductor wafer actual polishing.
2 . The method of creating according to claim 1 , wherein the in-plane temperature distribution parameter is a difference (Tmax−Tmin) between an in-plane maximum temperature Tmax and an in-plane minimum temperature Tmin.
3 . The method of creating according to claim 1 , wherein the in-plane polishing amount distribution parameter is a difference (Qmax−Qmin) between an in-plane maximum polishing amount Qmax and an in-plane minimum polishing amount Qmin.
4 . The method of creating according to claim 1 , wherein the polishing parameters are selected from the group consisting of polishing time τ, polishing slurry flow rate f, polishing pressure P, and surface plate/polishing head rotation speed ω.
5 . The method of creating according to claim 1 , wherein the correlation relational formula 1 is Δ ⁢ T = X 1 + X 2 ⁢ τ + X 3 ⁢ P + X 4 ⁢ ω + X 5 ⁢ f ΔT is a difference between an in-plane maximum temperature Tmax and an in-plane minimum temperature Tmin, τ is a polishing time, f is a polishing slurry flow rate, P is a polishing pressure, and ω is a surface plate/polishing head rotation speed, and X 1 , X 2 , X 3 , X 4 and X 5 are constants determined by correlation analysis.
6 . The method of creating according to claim 5 , wherein the correlation relational formula 2 is Δ ⁢ Q / Δ ⁢ T = Y 1 + Y 2 ⁢ τ + Y 3 ⁢ P + Y 4 ⁢ ω + Y 5 ⁢ f ΔQ is a difference between an in-plane maximum polishing amount Qmax and an in-plane minimum polishing amount Qmin, τ is the polishing time, f is the polishing slurry flow rate, P is the polishing pressure, ω is the surface plate/polishing head rotation speed, and Y 1 , Y 2 , Y 3 , Y 4 and Y 5 are constants determined by correlation analysis.
7 . The method of creating according to claim 6 , wherein the correlation relational formula 3 is Δ ⁢ Q = ( X 1 + X 2 ⁢ τ + X 3 ⁢ P + X 4 ⁢ ω + X 5 ⁢ f ) × ( Y 1 + Y 2 ⁢ τ + Y 3 ⁢ P + Y 4 ⁢ ω + Y 5 ⁢ f ) .
8 . A method of determining a polishing condition, the method comprising: creating a correlation relational formula for determining a polishing condition by method of creating according to claim 1 ; setting a target value or target range for in-plane polishing amount distribution of a semiconductor wafer to be polished; and determining, by the correlation relational formula, a polishing condition under which the set target value or target range can be expected to be achieved.
9 . A method of manufacturing a semiconductor wafer, the method comprising: determining a polishing condition by the method of determining according to claim 8 ; and polishing a semiconductor wafer under the determined polishing condition.
10 . The method of manufacturing according to claim 9 , wherein the semiconductor wafer is a silicon wafer.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to Japanese Patent Application No. 2021-079616 filed on May 10, 2021, which is expressly incorporated herein by reference in its entirety. TECHNICAL FIELD The present invention relates to a method of creating a correlation relational formula for determining a polishing condition, a method of determining a polishing condition, and a semiconductor wafer manufacturing method. BACKGROUND ART A semiconductor wafer manufacturing process usually includes a polishing step (see, for example, Japanese Patent Application Publication No. 2018-186118, which is expressly incorporated herein by reference in its entirety). SUMMARY OF INVENTION In a semiconductor wafer polishing step, a semiconductor wafer is polished under a predetermined polishing condition. However, the polishing condition to be determined usually includes a plurality of items. Conventionally, numerous trials and errors have to be repeated to determine these items. With the foregoing in view, an object of one aspect of the present invention is to provide novel means that makes it possible to determine a polishing condition for a semiconductor wafer without numerous trials and errors. One aspect of the present invention relates to a method of creating a correlation relational formula for determining a polishing condition (hereinafter, also referred to as “relational formula creation method”), the method including: polishing semiconductor wafers under a plurality of polishing conditions including a plurality of polishing parameters, and acquiring, by actual measurement, in-plane polishing amount distribution information on the semiconductor wafers in polishing under the plurality of polishing conditions;polishing semiconductor wafers under a plurality of polishing conditions including a plurality of polishing parameters, and acquiring, by actual measurement, in-plane temperature distribution information during semiconductor wafer polishing in polishing under the plurality of polishing conditions, or creating in-plane temperature distribution information during semiconductor wafer polishing under polishing conditions including a plurality of polishing parameters by heat transfer analysis;creating correlation relational formula 1 between a semiconductor wafer in-plane temperature distribution parameter and a plurality of polishing parameters on the basis of the in-plane temperature distribution information during polishing;creating correlation relational formula 2 between a semiconductor wafer in-plane polishing amount distribution parameter and a plurality of polishing parameters on the basis of the in-plane polishing amount distribution information; andcreating correlation relational formula 3 between a semiconductor wafer in-plane polishing amount distribution parameter and a plurality of polishing parameters on the basis of the correlation relational formula 1 and the correlation relational formula 2, whereinthe correlation relational formula 3 is a correlation relational formula to be used to determine a polishing condition in semiconductor wafer actual polishing. According to the above relational formula creation method, the correlation relational formula (correlation relational formula 3) used for determining the polishing conditions in actual polishing of the semiconductor wafer can be created by performing the various steps described above. That is, the correlation relational formula 3 can be determined without numerous trials and errors. Furthermore, the present inventor speculates, without placing limitation on the present invention, that the correlation relational formula 3 determined in such a way has been determined by taking into consideration the degree of influence of various polishing parameters on the basis of information acquired by actual measurement and/or information created by heat transfer analysis as described above, and therefore can be expected to contribute to the determination of the polishing condition under which semiconductor wafers can be polished with high accuracy. In one embodiment, the above temperature distribution parameter may be a difference (Tmax−Tmin) between the in-plane maximum temperature Tmax and the in-plane minimum temperature Tmin. In one embodiment, the above in-plane polishing amount distribution parameter may be a difference (Qmax−Qmin) between the in-plane maximum polishing amount Qmax and the in-plane minimum polishing amount Qmin. In one embodiment, the above polishing parameters may be selected from the group consisting of polishing time τ, polishing slurry flow rate f, polishing pressure P, and surface plate/polishing head rotation speed ω. In one embodiment, the above correlation relational formula 1 may be Δ⁢T=X1+X2 ⁢T+X3⁢P+X4⁢ω+X5⁢f ΔT is a difference between the in-plane maximum temperature Tmax and the in-plane minimum temperature Tmin, τ is a polishing time, f is a polishing slurry flow rate, P is a polishin