Method and system for dimensional uniformity using charged particle beam lithography

• US 9,343,267 B2
• Filed: 07/14/2014
• Issued: 05/17/2016
• 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): Memula, Suresh
• Application Number:
  US14/331,008
• Publication Number:
  US 20140359542A1
• Time in Patent Office: 673 Days
• Field of Search: 716/51, 716/52
• 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 1/78 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 method for fracturing or mask data preparation comprising:

determining pattern exposure information that is capable of forming 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 determining comprises calculating a sensitivity of the wafer pattern to changes in the reticle pattern, and wherein the determining is performed using a computing hardware device.

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

4. The method 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 method of claim 1 wherein the determining further comprises calculating 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 method of claim 5 wherein calculating the calculated reticle pattern comprises charged particle beam simulation.

7. The method of claim 6 wherein the charged particle beam simulation includes at least one of a group consisting of forward scattering, backward scattering, resist diffusion, Coulomb effect, etching, fogging, loading and resist charging.

8. The method 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.

9. The method of claim 8 wherein calculating the sensitivity of the wafer pattern to a given change in dimension of a feature on the reticle pattern comprises lithography simulation.

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

11. The method of claim 10 wherein the predetermined threshold is between 3.0-3.5.

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

13. The method of claim 1 wherein the calculating comprises calculating the sensitivity of the wafer pattern width to a width change in the reticle pattern, wherein the sensitivity is called the mask edge error factor (MEEF).