DESIGN RULE AND LITHOGRAPHIC PROCESS CO-OPTIMIZATION

• US 20150089459A1
• Filed: 04/16/2013
• Published: 03/26/2015
• 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
• Granted Patent: US 9,489,479 B2
• Time in Patent Office: Days
• US Class Current: 716/53
• 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 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.

2. The method of claim 1, wherein the optimizing comprises deriving values of the one or more design variables of the pattern transfer process and the one or more design variables of the one or more design rules that yield a favorable value of a metric characteristic of the pattern transfer process.

3. 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 one or more design variables of the pattern transfer process and one or more design variables of the one or more design rules.

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

5. The method of claim 1, wherein the one or more design variables of the pattern transfer process are selected from a group consisting of parameters of the lithographic projection apparatus and parameters of pre-exposure or post-exposure procedures.

6. The method of claim 1, wherein the one or more design variables of the one or more design rules comprise one or more constraints on parameters of patterns configured for being imaged via the pattern transfer process.

7. The method of claim 6, wherein the parameters of the patterns are 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 the one or more reticles, an aspect ratio of a pattern, and pitches of an array of patterns.

8. The method of claim 2, wherein the optimizing comprises changing one or more values of the one or more design variables of the pattern transfer process and the one or more design variables of the one or more design rules, until a termination condition is satisfied.

9. The method of claim 8, further comprising reevaluating the cost function.

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

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 iteration, and reaching a value of the cost function within a preset error limit,

11. The method of claim 1, wherein the optimizing is performed under constraints of at least one of the one or more design variables of the pattern transfer process and the one or more design variables of the one or more design rules.

12. The method of claim 3, wherein the cost function is a function of one or more of focus, CD, 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 focus shift.

13. The method of claim 5, wherein the pre-exposure or post-exposure procedures comprise one or more of pre-exposure or post-exposure baking (e.g., temperature and duration), postexposure etching (e.g., etchant composition, etching duration), resist coating, and resist development.

14. The method of claim 5, wherein the parameters of the lithographic projection apparatus comprise parameters of one or more of dose, mask bias, projection optics and illumination source shape.

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