SCANNER MODEL REPRESENTATION WITH TRANSMISSION CROSS COEFFICIENTS

• US 20100141925A1
• Filed: 10/29/2009
• Published: 06/10/2010
• Est. Priority Date: 11/10/2008
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Hunsche, Slefan, Ye, Jun, CAO, Yu, Koonmen, James Patrick
• Granted Patent: US 9,645,509 B2
• Time in Patent Office: Days
• US Class Current: 355/77
• 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: G03F 7/70508 Data handling in all parts of the microlithographic apparatus, e.g. handling pattern data for addressable masks or data transfer to or from different components within the exposure apparatus
• CPC Class Codes: G03F 7/70666 Aerial image, i.e. measuring the image of the patterned exposure light at the image plane of the projection system

Abstract

The present invention relates to a method for simulating aspects of a lithographic process. According to certain aspects, the present invention uses transmission cross coefficients to represent the scanner data and models. According to other aspects, the present invention enables sensitive data regarding various scanner subsystems to be hidden from third party view, while providing data and models useful for accurate lithographic simulation.

Claims

1. A method for simulating aspects of a lithographic process, comprising:

securing data regarding characteristics of a lithographic apparatus;

generating mathematical models representing the secured data; and

providing the mathematical models to a simulation process while keeping the secured data hidden to the simulation process.

2. A method for simulating aspects of a lithographic process, comprising:

providing information on one or more optical components, one or more optical properties, or both of a lithographic apparatus;

encapsulating the information of the one or more optical components by using a transformation function, wherein the transformation function secures the information; and

providing the encapsulated information to a simulation process to simulate a lithographic process.

3. A method according to claim 2, wherein the transformation function includes computing one or more transmission cross coefficients.

4. A method according to claim 2, wherein the information that is secured by the transformation function is unavailable to a user of the simulation process.

5. A method according to claim 2, wherein the one or more optical components include a illumination system, a projection system or both of the lithographic apparatus.

6. A method according to claim 2, wherein the one or more optical properties include illuminator shape and polarization, Jones pupil, focus blur due to laser bandwidth, focus blur due to chromatic aberrations.

7. A method according to claim 3, wherein the computed transmission cross coefficients are applied to a source-mask simulation process to determine process quality metrics of predicted contours of a mask layout data file.

8. A method according to claim 7, wherein the process quality metrics include one or more of normalized image log slope, mask error factor, and process window.

9. A method for simulating aspects of a lithographic process, comprising:

generating a model for simulating the aspects of the lithographic process;

inputting information about a plurality of aspects of the lithographic process to the model; and

using the model to transform the information into transformed information with a transformation of which the inverse is indeterminate given the transformed information only,

wherein the model allows obtaining the simulated aspects based on the transformed information and further information about other aspects of the lithographic process.

10. A method according to claim 9, wherein the plurality of aspects comprises at least one of illuminator shape, illuminator polarization, Jones pupil and focus blur.

11. A method according to claim 9, wherein the further information comprises information on the layout of a pattern on a patterning means.

12. A method according to claim 9, wherein the simulated aspects comprise at least one of aerial image intensity, normalized image log slope, mask error factor and process window.

13. A method according to claim 9, wherein the transformed information comprises a plurality of eigenvectors and eigen values of transmission cross coefficients.

14. A method according to claim 9, wherein the transformation is independent of the further information.