Etch bias characterization and method of using the same

Patent metadata

Field	Value
Publication number	US-12468232-B2
Application number	US-202318207642-A
Country	US
Kind code	B2
Filing date	Jun 8, 2023
Priority date	Feb 24, 2017
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

A method involving determining an etch bias for a pattern to be etched using an etch step of a patterning process based on an etch bias model, the etch bias model including a formula having a variable associated with a spatial property of the pattern or with an etch plasma species concentration of the etch step, and including a mathematical term including a natural exponential function to the power of a parameter that is fitted or based on an etch time of the etch step; and adjusting the patterning process based on the determined etch bias.

First claim

The invention claimed is:

1 . A method, comprising:
determining, by a hardware computer, an etch bias for a pattern to be etched using an etch step of a patterning process based on an etch bias model, the etch bias model comprising a mathematical term comprising a natural exponential function to the power of a parameter that is fitted or based on an etch time of the etch step; and adjusting the patterning process based on the determined etch bias.

2 . The method of claim 1 , wherein the parameter of the exponential function is fitted or based on the etch time and a reaction constant for the etch step.

3 . The method of claim 1 , wherein the model further comprises a variable associated with a spatial property of the pattern and the spatial property of the pattern comprises an initial pattern element dimension.

4 . The method of claim 1 , wherein the model further comprises a variable associated with a spatial property of the pattern multiplied with the mathematical term.

5 . The method of claim 1 , wherein the model further comprises a variable associated with an etch plasma species concentration.

6 . The method of claim 1 , wherein the model further comprises a variable associated with an etch plasma species concentration multiplied with the mathematical term.

7 . The method of claim 1 , wherein the model incorporates a patterning material concentration in the power of the exponential function.

8 . The method of claim 1 , wherein adjusting the patterning process comprises adjusting a border of a region of the patterning device according to the calculated etch bias.

9 . A computer program product comprising a non-transitory computer readable medium having stored instructions, the instructions, when executed by a computer system, configured to cause the computer system to at least:
determine an etch bias for a pattern to be etched using an etch step of a patterning process based on an etch bias model, the etch bias model comprising a mathematical term comprising a natural exponential function to the power of a parameter that is fitted or based on an etch time of the etch step; and cause an adjustment of the patterning process based on the determined etch bias.

10 . The computer program product of claim 9 , wherein the model further comprises a variable associated with a spatial property of the pattern and the spatial property of the pattern comprises an initial pattern element dimension.

11 . The computer program product of claim 9 , wherein the model further comprises a variable associated with a spatial property of the pattern multiplied with the mathematical term.

12 . The computer program product of claim 9 , wherein the model comprises a formula comprising a form of CD 0 (e kt −1), where CD 0 is a variable associated with a spatial property of the pattern and kt is the parameter that is fitted for the etch time t of the etch step and a reaction constant k for the etch step.

13 . The computer program product of claim 9 , wherein the model further comprises a variable associated with an etch plasma species concentration.

14 . The computer program product of claim 9 , wherein the model further comprises a variable associated with an etch plasma species concentration multiplied with the mathematical term.

15 . The computer program product of claim 9 , wherein the model comprises a formula comprising a form of C T0 (e kt −1), wherein C T0 is a variable associated with an etch plasma species concentration, and kt is the parameter that is fitted for the etch time t of the etch step and a reaction constant k for the etch step.

16 . The computer program product of claim 9 , wherein the model incorporates a patterning material concentration in the power of the exponential function.

17 . The computer program product of claim 9 , wherein the model comprises a formula comprising a form comprising

C

T
⁢
0

(

e

At
⁢

e

-
CR

s

-
1

)

,

where C T0 is a variable associated with an etch plasma species concentration, C R is a variable associated with a patterning material concentration, At is the parameter that is fitted for the etch time t of the etch step and a frequency factor A for the reaction of the etch step, and s is a constant for the etch step.

18 . A computer program product comprising a non-transitory computer readable medium having stored instructions, the instructions, when executed by a computer system, configured to cause the computer system to at least:
determine an etch bias for a pattern to be etched using an etch step of a patterning process based on an etch bias model, the etch bias model comprising a product of a variable associated with an etch plasma species concentration and a variable associated with a patterning material concentration; and cause an adjustment of the patterning process based on the determined etch bias.

19 . The computer program product of claim 18 , wherein the variable associated with an etch plasma species concentration comprises a variable associated with an etch plasma species spatial concentration and/or wherein the variable associated with a patterning material concentration comprises a variable associated with a patterning material spatial concentration.

20 . The computer program product of claim 18 , wherein the model comprises a formula comprising a form comprising Σ 0 n c n C T (t n )C R (t n ), wherein C T corresponds to the variable associated with an etch plasma species concentration, wherein C R corresponds to the variable associated with a patterning material concentration, wherein C T and C R are evaluated at n time intervals in the etch time, and t n and c n are etch rate coefficients.

Assignees

• Asml Netherlands Bv

Inventors

• Fan Yongfa
• Zheng Leiwu
• Feng Mu
• Zhao Qian
• Wang Jen-Shiang

Classifications

• H10P74/203

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

• H10P50/242

  of Group IV materials · CPC title

• G03F7/70625 Primary

  Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness · CPC title

• G03F1/80 Primary

  Etching · CPC title