Systems and methods for predicting layer deformation

Patent metadata

Field	Value
Publication number	US-2020320238-A1
Application number	US-201816763376-A
Country	US
Kind code	A1
Filing date	Nov 29, 2018
Priority date	Dec 4, 2017
Publication date	Oct 8, 2020
Grant date	—

Abstract

A method involving obtaining a resist deformation model for simulating a deformation process of a pattern in resist, the resist deformation model being a fluid dynamics model configured to simulate an intrafluid force acting on the resist, performing, using the resist deformation model, a computer simulation of the deformation process to obtain a deformation of the developed resist pattern for an input pattern to the resist deformation model, and producing electronic data representing the deformation of the developed resist pattern for the input pattern.

First claim

1 . A method, comprising:
initializing a resist deformation model for simulating a deformation process of a portion of a pattern in resist, the resist deformation model including a fluid dynamics model configured to simulate an intrafluid force acting on the resist; and performing, by a hardware computer system, a computer simulation of the deformation process using the fluid dynamics model to obtain a deformation of a developed resist pattern corresponding to an input pattern, the simulation being performed for a plurality of iterations until a criteria is satisfied, wherein in each iteration at least one parameter associated with the fluid dynamics model is updated.

2 . The method of claim 1 , wherein the fluid dynamics model is based on Navier-Stokes flow equations.

3 . The method of claim 1 , wherein the intrafluid force relates at least to surface tension.

4 . The method of claim 1 , wherein the deformation is determined at a plurality of locations, each location corresponding to a point that lies on a boundary of a developed portion of the developed resist pattern for the input pattern.

5 . The method of claim 1 , wherein the deformation of the developed resist pattern is obtained at a location by computing at least a velocity vector corresponding to a pixel, at the location, of an image associated with the input pattern.

6 . The method of claim 1 , wherein the at least one parameter associated with the fluid dynamics model comprises or relates to density of the resist, viscosity of the resist, surface tension of the resist, and/or time.

7 . The method of claim 1 , wherein the at least one parameter modified at each iteration of the computer simulation is an Ohnesorge number or a capillary number of the resist.

8 . The method of claim 1 , further comprising:
computing, using the fluid dynamics model, a dimension between a pair of locations disposed on a boundary of the developed resist pattern; and calculating an error between the computed dimension and a measured dimension of an actual developed resist pattern.

9 . The method of claim 8 , wherein the criteria corresponds to the calculated error meeting or crossing a certain error threshold.

10 . The method of claim 1 , further comprising:
obtaining values of parameters of the fluid dynamics model upon the criteria being satisfied; receiving a layout of another input pattern; and creating electronic data regarding deformation of a developed resist pattern corresponding to the other input pattern using the fluid dynamics model based on the obtained values of the parameters of the fluid dynamics model.

11 . (canceled)

12 . The method of claim 1 , wherein the input pattern is in the form of a binary image.

13 . The method of claim 1 , wherein the initializing further comprises applying a set of boundary conditions to the fluid dynamics model.

14 . The method of claim 1 , wherein the resist deformation model is specified for at least two liquids in the resist pattern, wherein each of the at least two liquids has a different viscosity.

15 . (canceled)

16 . The method of claim 12 , further comprising generating the binary image, the generating comprising:
obtaining a patterning device pattern corresponding to the input pattern; producing an aerial image based on the patterning device pattern; and extracting boundaries of the pattern in the aerial image to generate the binary image.

17 . The method of claim 13 , wherein the set of boundary conditions comprises setting a pressure value of the resist at a boundary of the developed resist pattern to zero.

18 . The method of claim 1 , wherein the at least one parameter associated with the fluid dynamics model comprises or relates to an Ohnesorge number corresponding to the resist, wherein density of the resist, viscosity of the resist, and surface tension of the resist are related to each other by the Ohnesorge number corresponding to the resist or wherein the at least one parameter associated with the fluid dynamics model comprises or relates to a capillary number, wherein viscosity of the resist and surface tension of the resist are related to each other by the capillary number.

19 . A non-transitory computer program product comprising machine-readable instructions, the instructions, upon execution by a processing system, configured to cause the processor system to at least:
initialize a resist deformation model for simulating a deformation process of a portion of a pattern in resist, the resist deformation model including a fluid dynamics model configured to simulate an intrafluid force acting on the resist; and perform a computer simulation of the deformation process using the fluid dynamics model to obtain a deformation of a developed resist pattern corresponding to an input pattern, the simulation being performed for a plurality of iterations until a criteria is satisfied, wherein in each iteration at least one parameter associated with the fluid dynamics model is updated.

20 . The computer program product of claim 19 , wherein the deformation is determined at a plurality of locations, each location corresponding to a point that lies on a boundary of a developed portion of the developed resist pattern for the input pattern.

21 . The computer program product of claim 19 , wherein the deformation of the developed resist pattern is obtained at a location by computation of at least a velocity vector corresponding to a pixel, at the location, of an image associated with the input pattern.

22 . The computer program product of claim 19 , wherein the at least one parameter associated with the fluid dynamics model comprises or relates to density of the resist, viscosity of the resist, surface tension of the resist, and/or time.

Assignees

• Asml Netherlands Bv

Inventors

• Batistakis Chrysostomos
• Middlebrooks Scott Anderson
• Wuister Sander Frederik

Classifications

• G03F7/705

  Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions · CPC title

• G06F30/28 Primary

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

• G06F2119/14

  Force analysis or force optimisation, e.g. static or dynamic forces · CPC title

• G03F7/70608 Primary

  Monitoring the unpatterned workpiece, e.g. measuring thickness, reflectivity or effects of immersion liquid on resist · CPC title