Method and system for determining in-plane distortions in a substrate

Patent metadata

Field	Value
Publication number	US-10024654-B2
Application number	US-201615091021-A
Country	US
Kind code	B2
Filing date	Apr 5, 2016
Priority date	Apr 6, 2015
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

The determination of in-plane distortions of a substrate includes measuring one or more out-of-plane distortions of the substrate in an unchucked state, determining an effective film stress of a film on the substrate in the unchucked state based on the measured out-of-plane distortions of the substrate in the unchucked state, determining in-plane distortions of the substrate in a chucked state based on the effective film stress of the film on the substrate in the unchucked state and adjusting at least one of a process tool or an overlay tool based on at least one of the measured out-of-plane distortions or the determined in-plane distortions.

First claim

What is claimed:

1. A system for determining in-plane distortions of a substrate comprising:
a substrate geometry measurement tool configured to measure out-of-plane distortions of the substrate in an unchucked state; and
a controller communicatively coupled to the measurement tool, the controller including one or more processors configured to execute a set of program instructions, the program instructions configured to cause the one or more processors to:
receive one or more measurement results indicative of out-of-plane distortions of the substrate in the unchucked state from the measurement tool;
determine an effective surface film stress of the substrate in the unchucked state based on the measured out-of-plane distortions of the substrate in the unchucked state with a two-dimensional plate model;
determine in-plane distortions of the substrate in a chucked state based on the effective surface film stress of the substrate in the unchucked state with the two-dimensional plate model; and
provide the at least one of the measured out-of-plane distortions or the determined in-plane distortions to at least one of a process tool or a metrology tool to adjust the at least one of the process tool or the metrology tool based on the at least one of the measured out-of-plane distortions or the determined in-plane distortions.

2. The system of claim 1 , wherein the substrate geometry measurement tool comprises:
a dual Fizeau interferometer.

3. The system of claim 1 , wherein the determining an effective film stress of the substrate in the unchucked state based on the measured out-of-plane distortions of the substrate in the unchucked state with a two-dimensional plate model comprises:
applying a fitting function to the measured out-of-plane distortions; and
determining the effective film stress of the substrate in the unchucked state based on the fitted function with the two-dimensional plate model.

4. The system of claim 3 , wherein the fitting function comprises:
a Zernike polynomial.

5. The system of claim 1 , wherein the determining an effective film stress of the substrate in the unchucked state based on the measured out-of-plane distortions of the substrate in the unchucked state with a two-dimensional plate model comprises:
applying a finite difference approximation to determine the effective film stress of the substrate in the unchucked state with the two-dimensional plate model.

6. The system of claim 1 , wherein the determining an effective film stress of the substrate in the unchucked state based on the measured out-of-plane distortions of the substrate in the unchucked state with a two-dimensional plate model comprises:
applying a finite element approximation to determine the effective film stress of the substrate in the unchucked state with the two-dimensional plate model.

7. The system of claim 1 , wherein the determining an effective film stress of the substrate in the unchucked state based on the measured out-of-plane distortions of the substrate in the unchucked state with a two-dimensional plate model comprises:
applying a finite volume approximation to determine the effective film stress of the substrate in the unchucked state with the two-dimensional plate model.

8. The system of claim 1 , wherein the determining in-plane distortions of the substrate in a chucked state based on the effective film stress of the substrate in the unchucked state with the two-dimensional plate model comprises:
applying a finite difference approximation to determine the in-plane distortions of the substrate in a chucked state based on the effective film stress of the substrate in the unchucked state with the two-dimensional plate model.

9. The system of claim 1 , wherein the determining in-plane distortions of the substrate in a chucked state based on the effective film stress of the substrate in the unchucked state with the two-dimensional plate model comprises:
applying a finite element approximation to determine the in-plane distortions of the substrate in a chucked state based on the effective film stress of the substrate in the unchucked state with the two-dimensional plate model.

10. The system of claim 1 , wherein the determining in-plane distortions of the substrate in a chucked state based on the effective film stress of the substrate in the unchucked state with the two-dimensional plate model comprises:
applying a finite volume approximation to determine the in-plane distortions of the substrate in a chucked state based on the effective film stress of the substrate in the unchucked state with the two-dimensional plate model.

11. The system of claim 1 , wherein the determining in-plane distortions of the substrate in a chucked state based on the effective film stress of the substrate in the unchucked state with the two-dimensional plate model comprises:
applying a method of moments approximation to determine the in-plane distortions of the substrate in a chucked state based on the effective film stress of the substrate in the unchucked state with the two-dimensional plate model.

12. The system of claim 1 , wherein the metrology tool comprises:
an overlay metrology tool.

13. The system of claim 1 , wherein the substrate comprises:
a semiconductor wafer.

14. A system for determining in-plane distortions of a substrate comprising:
a substrate geometry measurement tool configured to measure out-of-plane distortions of the substrate in an unchucked state; and
a controller communicatively coupled to the measurement tool, the controller including one or more processors configured to execute a set of program instructions, the program instructions configured to cause the one or more processors to:
receive one or more measurement results indicative of out-of-plane distortions of the substrate in the unchucked state from the measurement tool;
apply a two-dimensional plate model to determine in-plane distortions of the substrate in a chucked state based on the out-of-plane distortions of the substrate in the unchucked state; and
provide the at least one of the measured out-of-plane distortions or the determined in-plane distortions to at least one of a process tool or an overlay tool to adjust the at least one of the process tool or the overlay tool based on the at least one of the measured out-of-plane distortions or the determined in-plane distortions.

15. A system for determining in-plane distortions of a substrate comprising:
a substrate geometry measurement tool configured to measure out-of-plane distortions of the substrate in an unchucked state; and
a controller communicatively coupled to the measurement tool, the controller including one or more processors configured to execute a set of program instructions, the program instructions configured to cause the one or more processors to:
receive one or more measurement results indicative of out-of-plane distortions of the substrate in the unchucked state from the measurement tool;
apply an Euler-Lagrange plate model to determine in-plane distortions of the substrate in a chucked state based on the out-of-plane distortions of the substrate in the unchucked state; and

provide the at least one of the measured out-of-plane distortions or the determined in-plane distortions to at least one of a process tool or an overlay tool to adjust the at least one of the process tool or the overlay tool based on the at least one of the measured out-of-plane distortions or the determined in-plane distortions.

16. A method for determining in-plane distortions of a substrate comprising:
measuring one or more out-of-plane distortions

Assignees

• Kla Tencor Corp

Inventors

• Smith Mark D
• Solomon Jose
• Sherwin Stuart
• Mieher Walter
• Levy Ady

Classifications

• H10P74/203 Primary

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• G01B2210/56

  Measuring geometric parameters of semiconductor structures, e.g. profile, critical dimensions or trench depth · CPC title

• G01B11/161 Primary

  by interferometric means · CPC title

• G01B11/2441

  using interferometry · CPC title

• G01B9/02027

  Two or more interferometric channels or interferometers · CPC title