Three-dimensional mask model for photolithography simulation

• US 9,372,957 B2
• Filed: 01/20/2015
• Issued: 06/21/2016
• Est. Priority Date: 08/14/2007
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Liu, Peng, Cao, Yu, Chen, Luoqi, Ye, Jun
• Primary Examiner(s): GARBOWSKI, LEIGH M
• Application Number:
  US14/600,337
• Publication Number:
  US 20150135146A1
• Time in Patent Office: 518 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G03F 1/36 Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes
• CPC Class Codes: G03F 1/50 Mask blanks not covered by G03F1/20 - G03F1/34; Preparation thereof
• CPC Class Codes: G03F 1/70 Adapting basic layout or design of masks to lithographic process requirements, e.g., second iteration correction of mask patterns for imaging
• CPC Class Codes: G03F 1/76 Patterning of masks by imaging
• CPC Class Codes: G03F 7/70441 Optical proximity correction [OPC]
• CPC Class Codes: G03F 7/705 Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions
• CPC Class Codes: G06F 2111/10 Numerical modelling
• CPC Class Codes: G06F 2119/18 Manufacturability analysis or optimisation for manufacturability
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30
• CPC Class Codes: G06F 30/30 Circuit design
• CPC Class Codes: G06F 30/33 Design verification, e.g. functional simulation or model checking
• CPC Class Codes: G06F 30/337 Design optimisation
• CPC Class Codes: G06F 30/39 Circuit design at the physical level physical level design for reconfigurable circuits G06F30/347
• CPC Class Codes: G06F 30/398 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

Abstract

A three-dimensional mask model of the invention provides a more realistic approximation of the three-dimensional effects of a photolithography mask with sub-wavelength features than a thin-mask model. In one embodiment, the three-dimensional mask model includes a set of filtering kernels in the spatial domain that are configured to be convolved with thin-mask transmission functions to produce a near-field image. In another embodiment, the three-dimensional mask model includes a set of correction factors in the frequency domain that are configured to be multiplied by the Fourier transform of thin-mask transmission functions to produce a near-field image.

Claims

1. A method comprising:

applying, by a computer, a thin mask model to a mask design layout to create a thin mask transmission;

obtaining a plurality of edge-based kernels to adapt the thin mask transmission to a mask 3D transmission; and

combining the thin mask transmission and the plurality of edge-based kernels to create a mask 3D transmission corresponding to the mask design layout.

2. The method of claim 1, wherein the plurality of edge-based kernels are for transverse electric (TE) polarization and transverse magnetic (TM) polarization.

3. The method of claim 1, wherein obtaining the plurality of edge-based kernels includes:

receiving a mask topography structure for the mask design layout;

performing a rigorous simulation to simulate a near-field; and

deriving the plurality of edge-based kernels from the near-field.

4. The method of claim 1, wherein the mask 3D transmission is in a spatial domain form.

5. The method of claim 1, wherein the mask 3D transmission is in a frequency domain form.

6. A non-transitory computer readable medium having instructions stored thereon which, when executed by a computer, cause the computer to perform a method comprising:

applying a thin mask model to a mask design layout to create a thin mask transmission;

obtaining a plurality of edge-based kernels to adapt the thin mask transmission to a mask 3D transmission; and

combining the thin mask transmission and the plurality of edge-based kernels to create a mask 3D transmission corresponding to the mask design layout.

7. The computer-readable medium of claim 6, wherein the plurality of edge-based kernels are for transverse electric (TE) polarization and transverse magnetic (TM) polarization.

8. The computer-readable medium of claim 6, wherein obtaining the plurality of edge-based kernels includes:

receiving a mask topography structure for the mask design layout;

performing a rigorous simulation to simulate a near-field; and

deriving the plurality of edge-based kernels from the near-field.

9. The computer-readable medium of claim 6, wherein the mask 3D transmission is in a spatial domain form.

10. The computer-readable medium of claim 6, wherein the mask 3D transmission is in a frequency domain form.

11. A method, implemented by a computer, of performing mask topography effect modeling on a mask design layout, the method comprising:

applying, using the computer, a thin mask model to the mask design layout to create a thin mask transmission;

applying a thick mask model to the mask design layout to generate a mask 3D residual, the thick mask model comprising a plurality of edge-based kernels; and

combining the thin mask transmission and the mask 3D residual to create a mask 3D transmission, wherein the mask topography effect modeling on the mask design layout is used to create an improved optical mask for creating an integrated circuit.