Method and system for dimensional uniformity using charged particle beam lithography

• US 10,431,422 B2
• Filed: 12/13/2017
• Issued: 10/01/2019
• Est. Priority Date: 04/18/2012
• Status: Active Grant

• Current Assignee: D2S, Inc.
• Original Assignee: D2S, Inc.
• Inventors: Fujimura, Akira, Hagiwara, Kazuyuki, Pack, Robert C.
• Primary Examiner(s): Ippolito, Nicole M
• Application Number:
  US15/841,167
• Publication Number:
  US 20180108513A1
• Time in Patent Office: 657 Days
• Field of Search: 250396 R, 250397, 2504921, 2504922, 25049221, 25049222, 25049223, 2504923
• 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 1/78 by charged particle beam [CPB], e.g. electron beam patterning of masks
• CPC Class Codes: G03F 7/2063 for the production of exposure masks or reticles
• CPC Class Codes: H01J 2237/31762 Computer and memory organisation
• CPC Class Codes: H01J 2237/31764 Dividing into sub-patterns
• CPC Class Codes: H01J 2237/31771 using multiple exposure
• CPC Class Codes: H01J 2237/31774 Multi-beam
• CPC Class Codes: H01J 2237/31776 Shaped beam
• CPC Class Codes: H01J 37/3023 Programme control
• CPC Class Codes: H01J 37/3026 Patterning strategy
• CPC Class Codes: H01J 37/3174 Particle-beam lithography, e.g. electron beam lithography
• CPC Class Codes: H01J 37/3177 Multi-beam, e.g. fly's eye, comb probe

Abstract

A method for mask process correction or forming a pattern on a reticle using charged particle beam lithography is disclosed, where the reticle is to be used in an optical lithographic process to form a pattern on a wafer, where sensitivity of the wafer pattern is calculated with respect to changes in dimension of the reticle pattern, and where pattern exposure information is modified to increase edge slope of the reticle pattern where sensitivity of the wafer pattern is high. A method for fracturing or mask data preparation is also disclosed, where pattern exposure information is determined that can form a pattern on a reticle using charged particle beam lithography, where the reticle is to be used in an optical lithographic process to form a pattern on a wafer, and where sensitivity of the wafer pattern is calculated with respect to changes in dimension of the reticle pattern.

Claims

1. A system for fracturing or mask data preparation, the system comprising:

a device configured to determine pattern exposure information that forms a reticle pattern on a resist-coated reticle with a charged particle beam writer;

wherein the reticle is to be used to form a wafer pattern on a substrate using optical lithography; and

wherein the device configured to determine calculates a sensitivity of the wafer pattern to changes in dimension of the reticle pattern.

2. The system of claim 1 wherein the charged particle beam writer is a shaped beam charged particle beam writer, and wherein the pattern exposure information comprises a plurality of shots for the shaped beam charged particle beam writer.

3. The system of claim 2 wherein a shot dosage of each shot in the plurality of shots is unspecified before proximity effect correction (PEC) is done.

4. The system of claim 1 wherein the charged particle beam writer is a multi-beam charged particle beam system, and wherein the pattern exposure information comprises exposure instructions for the multi-beam charged particle beam exposure system.

5. The system of claim 1 wherein the device configured to determine is configured to calculate a calculated reticle pattern from the pattern exposure information, and wherein the sensitivity of the wafer pattern is calculated with respect to changes in the calculated reticle pattern.

6. The system of claim 5 wherein the calculation of the calculated reticle pattern comprises charged particle beam simulation.

7. The system of claim 1 wherein calculating the sensitivity of the wafer pattern comprises calculating a change in dimension of a feature on the wafer pattern for a given change in dimension of a feature on the reticle pattern.

8. The system of claim 7 wherein the device configured to determine performs lithography simulation.

9. The system of claim 1 wherein the determining of pattern exposure information comprises providing a higher-than-normal dosage to the reticle near a perimeter of the reticle pattern in areas where the calculated sensitivity of the wafer pattern is higher than a predetermined threshold.

10. The system of claim 9 wherein the pattern exposure information comprises a plurality of shots for a shaped beam charged particle beam writer, and wherein the higher-than-normal dosage is provided using overlapping shots.

11. The system of claim 1 wherein the calculating is subdivided into a plurality of 2-dimensional geometric regions for one or more calculation-intensive steps, to support parallel processing.

12. The system of claim 1 wherein the device configured to determine comprises a graphics processing unit (GPU).

13. The system of claim 1 wherein the device configured to determine pattern exposure information performs an iterative processing of revising and recalculating possible solutions.

14. The system of claim 13 wherein the iterative processing minimizes a total number of shots.

15. The system of claim 13 wherein the iterative processing minimizes a total charged particle beam writing time.