Method for predicting resist deformation

Patent metadata

Field	Value
Publication number	US-11914942-B2
Application number	US-202318206029-A
Country	US
Kind code	B2
Filing date	Jun 5, 2023
Priority date	Dec 31, 2018
Publication date	Feb 27, 2024
Grant date	Feb 27, 2024

Abstract

A method for determining a deformation of a resist in a patterning process. The method involves obtaining a resist deformation model of a resist having a pattern, the resist deformation model configured to simulate a fluid flow of the resist due to capillary forces acting on a contour of at least one feature of the pattern; and determining, via the resist deformation model, a deformation of a resist pattern to be developed based on an input pattern to the resist deformation model.

First claim

The invention claimed is:

1. A method comprising:
inputting, into a resist deformation model, pattern information relating to a pattern to be formed in a patterning process, the model configured to simulate deformation of a portion of a resist, the portion comprising a boundary liquid layer located at a boundary between a developed or open region in the resist and a region of the resist at least partly surrounding the developed or open region, wherein the model is configured to determine a first deformation component of the boundary liquid layer caused by fluid flow of the boundary liquid layer and a second deformation component of the boundary liquid layer caused by the fluid flow of the boundary liquid layer; and
evaluating, by a hardware processor system, the resist deformation model with the inputted pattern information to determine a deformation of the pattern to be formed in the resist, wherein the deformation comprises a combination of the first deformation component and the second deformation component of the boundary liquid layer.

2. The method of claim 1 , wherein the boundary liquid layer has a thickness smaller than a length of the developed or open region in the resist at the boundary.

3. The method of claim 1 , wherein the first deformation component is determined in a horizontal plane based on a horizontal component of a flow rate of the boundary liquid layer and the second deformation is determined in the horizontal plane based on a vertical component of the flow rate of the boundary liquid layer.

4. The method of claim 1 , wherein the model has defined therein, a boundary condition comprising a velocity gradient approximately equal to zero at a surface of the boundary liquid layer, the surface being opposite of the developed or open region.

5. The method of claim 1 , wherein the model has defined therein, a boundary condition comprising a velocity approximately equal to zero at a surface of the boundary liquid layer at the developed or open region.

6. The method of claim 1 , wherein the model has defined therein, a velocity as a function of thickness of the boundary liquid layer and a pressure gradient across a thickness of the boundary liquid layer.

7. The method of claim 6 , wherein the model has defined therein, the flow rate of the boundary liquid layer as a function of an integration of the velocity over the thickness of the boundary liquid layer.

8. The method of claim 1 , wherein the model has defined therein, the deformation as a function of the flow rate of the boundary liquid layer.

9. The method of claim 1 , wherein the evaluating comprises:
determination of the first deformation component in a first plane caused by a horizontal component of a flow rate of the boundary liquid layer; and
determination of a final deformation in the first plane by adjusting the first deformation component based on a vertical component of the flow rate of the boundary liquid layer in a second plane, the second plane perpendicular to the first plane.

10. The method of claim 1 , wherein the evaluating further comprises:
definition of a plurality of vertices along a contour of the developed or open region in the resist;
determination of a capillary force at a given vertex along the contour; and
redistribution of the vertices such that (i) a volume of the developed or open region in the resist is conserved, and (ii) a volume of the boundary liquid layer is conserved.

11. The method of claim 10 , wherein the redistribution of the vertices comprises:
determination of a time scale based on a horizontal component of a flow rate of the boundary liquid layer; and
movement, based on the time scale and the flow rate of the boundary layer, the plurality of vertices.

12. The method of claim 10 , further comprising:
determining a rate of change of a thickness of the boundary liquid layer based on the flow rate of the boundary layer; and
adjusting, based on the redistributed vertices, another plurality of vertices along a surface of the boundary liquid layer based on the rate of change of thickness of the boundary liquid layer.

13. The method of claim 1 , wherein the model is a thin-film model simplified based on a lubrication approximation, wherein the lubrication approximation comprises a vertical shear stress value of zero.

14. A non-transitory computer program product comprising machine-readable instructions stored therein, the instructions, when executed by one or more processors, configured to cause the one or more processors to at least perform the method of claim 1 .

15. A method comprising:
inputting, into a resist deformation model, pattern information relating to a pattern to be formed in a patterning process, the model configured to simulate deformation of a portion of a resist, the portion comprising a boundary liquid layer located at a boundary between a developed or open region in the resist and a region of the resist at least partly surrounding the developed or open region, wherein the model is configured to determine a deformation of the boundary liquid layer caused by a horizontal fluid flow of the boundary liquid layer; and
determining, by a hardware computer system, a deformation of the pattern to be formed in the resist by simulation using the resist deformation model based on the input pattern information.

16. The method of claim 15 , wherein the model is further configured to determine a deformation of the boundary liquid layer caused by a vertical fluid flow of the boundary liquid layer.

17. The method of claim 15 , wherein the boundary liquid layer has a thickness smaller than a length of the developed or open region in the resist at the boundary.

18. The method of claim 15 , wherein the model has defined therein, a boundary condition comprising a velocity gradient approximately equal to zero at a surface of the boundary liquid layer, the surface being opposite of the developed or open region.

19. The method of claim 15 , wherein the model has defined therein, a boundary condition comprising a velocity approximately equal to zero at a surface of the boundary liquid layer at the developed or open region.

20. A non-transitory computer program product comprising machine-readable instructions stored therein, the instructions, when executed by one or more processors, configured to cause the one or more processors to at least perform the method of claim 15 .

Assignees

• Asml Netherlands Bv

Inventors

• Batistakis Chrysostomos
• Jeurissen Roger Josef Maria
• Winkels Koen Gerhardus

Classifications

• G06F2119/18

  Manufacturability analysis or optimisation for manufacturability · CPC title

• G06F2111/10

  Numerical modelling · CPC title

• G06F30/398 Primary

  Design verification or optimisation, e.g. using design rule check [DRC], layout versus schematics [LVS] or finite element methods [FEM] (optical proximity correction [OPC] design processes G03F1/36) · CPC title

• G06F30/3308

  using simulation · CPC title

• G06F30/28

  using fluid dynamics, e.g. using Navier-Stokes equations or computational fluid dynamics [CFD] · CPC title