Rule and lithographic process co-optimization

• US 9,489,479 B2
• Filed: 04/16/2013
• Issued: 11/08/2016
• Est. Priority Date: 05/04/2012
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Liu, Xiaofeng
• Primary Examiner(s): Whitmore, Stacy
• Application Number:
  US14/398,416
• Publication Number:
  US 20150089459A1
• Time in Patent Office: 1,302 Days
• Field of Search: 716 50- 52
• US Class Current: 1/1
• 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 7/70525 Controlling normal operating mode, e.g. matching different apparatus, remote control or prediction of failure
• CPC Class Codes: G03F 7/7065 Defects, e.g. optical inspection of patterned layer for defects
• CPC Class Codes: G06F 2119/18 Manufacturability analysis or optimisation for manufacturability
• CPC Class Codes: G06F 30/30 Circuit design
• 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
• CPC Class Codes: H05K 2203/05 Patterning and lithography; Masks; Details of resist
• CPC Class Codes: H05K 3/0005 for designing circuits by computer

Abstract

A computer-implemented method for obtaining values of one or more design variables of one or more design rules for a pattern transfer process comprising a lithographic projection apparatus, the method comprising: simultaneously optimizing one or more design variables of the pattern transfer process and the one or more design variables of the one or more design rules. The optimizing comprises evaluating a cost function that measures a metric characteristic of the pattern transfer process, the cost function being a function of one or more design variables of the pattern transfer process and one or more design variables of the one or more design rules.

Claims

1. A method comprising:

optimizing, by a hardware computer system, a design variable of a pattern transfer process, involving a lithographic apparatus, for manufacturing devices and optimizing a design variable of a design rule for the pattern transfer process based on the optimizing of the design variable of the pattern transfer process, to determine a value of the design variable of the design rule; and

using the design rule with the determined value to configure the pattern transfer process.

2. The method of claim 1, wherein the optimizing comprises deriving values of the design variable of the pattern transfer process and the design variable of the design rule that yield a favorable value of a metric characteristic of the pattern transfer process.

3. The method of claim 2, wherein the metric characteristic of the pattern transfer process is a process window of the pattern transfer process.

4. The method of claim 1, wherein the optimizing comprises evaluating a cost function that measures a metric characteristic of the pattern transfer process, the cost function being a function of the design variable of the pattern transfer process and the design variable of the design rule.

5. The method of claim 4, wherein the cost function is a function of one or more selected from:

focus, critical dimension, image shift, image distortion, image rotation, edge placement error, resist contour distance, critical dimension uniformity, dose variation, focus variation, process condition variation, mask error (MEEF), mask complexity defect size, and/or focus shift.

6. The method of claim 4 , wherein the optimizing comprises changing values of the design variable of the pattern transfer process and the design variable of the design rule, until a termination condition is satisfied.

7. The method of claim 6, further comprising reevaluating the cost function.

8. The method of claim 6, wherein the termination condition includes one or more selected from:

minimization of the cost function;

maximization of the cost function;

reaching a preset number of iterations;

reaching a value of the cost function equal to or beyond a preset threshold value;

reaching a predefined computation time;

reaching a preset number of iterations; and

/or

reaching a value of the cost function within a preset error limit.

9. The method of claim 1, wherein the design variable of the pattern transfer process is selected from a group consisting of a parameter of the lithographic apparatus, a parameter of a pre-exposure procedure and a parameter of a post-exposure procedure.

10. The method of claim 9, wherein the parameter comprises a parameter of a pre-exposure procedure or post-exposure procedure and the parameter of the pre-exposure or post-exposure procedure comprises one or more selected from:

a pre-exposure or post-exposure baking parameter, a post-exposure etching parameter, a resist coating parameter, and/or a resist development parameter.

11. The method of claim 9, wherein the parameter comprises a parameter of the lithographic apparatus and the parameter of the lithographic apparatus comprises one or more selected from:

dose, mask bias, a projection optics parameter and/or illumination source shape parameter.

12. The method of claim 1, wherein the design variable of the design rule comprises a constraint on a parameter of a pattern configured for being imaged via the pattern transfer process.

13. The method of claim 12, wherein the parameter of the pattern is selected from a group consisting of an edge-to-edge distance between two patterns, a height of a pattern, a width of a pattern, an absolute position of an edge of a pattern, a distance between an edge of a pattern to an extended line of another edge of the same pattern or of a different pattern, a corner-to-corner distance, a dimension of an overlap between two patterns, a distance between an edge of a pattern to a fixed point on a reticle, an aspect ratio of a pattern, and a pitch of an array of patterns.

14. The method of claim 1, wherein the optimizing is performed under a constraint of the design variable of the pattern transfer process and/or the design variable of the design rule.

15. A computer program product comprising a non-transitory computer readable medium having instructions recorded thereon, the instructions when executed by a computer implementing the method of claim 1.

16. The method of claim 1, wherein using the design rule comprises using the design rule with the determined value to generate a pattern layout for a physical patterning device and outputting an electronic data structure of the generated pattern layout for the manufacture or control of the physical patterning device.

17. The method of claim 1, wherein the optimizing comprises simultaneously optimizing the design variable of the pattern transfer process and the design variable of the design rule for the pattern transfer process.

18. The method of claim 17, wherein using the design rule comprises using the design rule with the value of the design variable of the design rule at the termination condition to generate a pattern layout for a physical patterning device and outputting an electronic data structure of the generated pattern layout for the manufacture or control of the physical patterning device.

19. A method comprising:

evaluating, by a hardware computer system, a cost function that assesses a metric characteristic of a pattern transfer process, involving a lithographic apparatus and physical patterning device, for manufacturing devices, the cost function being a function of a design variable of the pattern transfer process and a design variable of a design rule for the pattern transfer process;

changing a value of the design variable of the pattern transfer process and/or the design variable of the design rule and re-evaluating, by the hardware computer system, the cost function based on the changed value, until a termination condition is satisfied; and

using the design rule with the value of the design variable of the design rule at the termination condition, to configure the pattern transfer process.

20. A computer program product comprising a non-transitory computer readable medium having instructions recorded thereon, the instructions, when executed by a computer, configured to cause the computer to:

optimize a design variable of a pattern transfer process, involving a lithographic apparatus, for manufacturing devices and optimize a design variable of a design rule for the pattern transfer process based on the optimizing of the design variable of the pattern transfer process, to determine a value of the design variable of the design rule; and

use the design rule with the determined value to configure the pattern transfer process.

21. A computer program product comprising a non-transitory computer readable medium having instructions recorded thereon, the instructions, when executed by a computer, configured to cause the computer to:

evaluate a cost function that assesses a metric characteristic of a pattern transfer process, involving a lithographic apparatus and physical patterning device, for manufacturing devices, the cost function being a function of a design variable of the pattern transfer process and a design variable of a design rule for the pattern transfer process;

change a value of the design variable of the pattern transfer process and/or the design variable of the design rule and re-evaluate, by the hardware computer system, the cost function based on the changed value, until a termination condition is satisfied; and

use the design rule with the value of the design variable of the design rule at the termination condition, to configure the pattern transfer process.