Method and system for forming patterns with charged particle beam lithography

• US 9,465,297 B2
• Filed: 05/18/2015
• Issued: 10/11/2016
• Est. Priority Date: 06/25/2011
• Status: Active Grant

• Current Assignee: D2S, Inc.
• Original Assignee: D2S, Inc.
• Inventors: Fujimura, Akira, Bork, Ingo
• Primary Examiner(s): YOUNG, CHRISTOPHER G
• Application Number:
  US14/715,136
• Publication Number:
  US 20150261907A1
• Time in Patent Office: 512 Days
• Field of Search: 430/5, 430/30, 430/296, 430/942
• US Class Current: 1/1
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G03F 1/20 Masks or mask blanks for imaging by charged particle beam [CPB] radiation, e.g. by electron beam; Preparation thereof
• CPC Class Codes: G03F 1/78 by charged particle beam [CPB], e.g. electron beam patterning of masks
• CPC Class Codes: G03F 7/2037 Exposure with X-ray radiation or corpuscular radiation, through a mask with a pattern opaque to that radiation
• CPC Class Codes: G03F 7/2063 for the production of exposure masks or reticles
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30
• 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: H01J 2237/31764 Dividing into sub-patterns
• CPC Class Codes: H01J 2237/31771 using multiple exposure
• CPC Class Codes: H01J 2237/31776 Shaped beam
• CPC Class Codes: H01J 37/147 Arrangements for directing or deflecting the discharge along a desired path H01J37/045 take precedence; lenses H01J37/10
• CPC Class Codes: H01J 37/3174 Particle-beam lithography, e.g. electron beam lithography
• CPC Class Codes: H01J 37/3175 Projection methods, i.e. transfer substantially complete pattern to substrate
• CPC Class Codes: H01L 21/027 Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34 photographic masks or originals per se G03F1/00; registration or positioning of photographic masks or originals G03F9/00; photographic cameras G03B; control of position G05D3/00
• CPC Class Codes: Y10S 430/143 Electron beam

Abstract

In a method for fracturing or mask data preparation or mask process correction for charged particle beam lithography, a plurality of shots are determined that will form a pattern on a surface, where shots are determined so as to reduce sensitivity of the resulting pattern to changes in beam blur (β_f). In some embodiments, the sensitivity to changes in β_f is reduced by varying the charged particle surface dosage for a portion of the pattern. Methods for forming patterns on a surface, and for manufacturing an integrated circuit are also disclosed, in which pattern sensitivity to changes in β_f is reduced.

Claims

1. A method for use with a charged particle beam lithographic process comprising a beam blur (β

_f), the method comprising;

determining, during a fracturing or a mask data preparation or a mask process correction, a set of charged particle beam shots that will form a desired pattern on a surface by producing a charged particle dosage on the surface,

wherein the determining comprises calculating a pattern formed on the surface, and wherein the calculating includes variation of β

_f due to variation in Coulomb effect.

2. The method of claim 1 wherein the Coulomb effect for a shot in the set of charged particle beam shots depends on an area of the shot.

3. The method of claim 1 wherein shots in the set of charged particle beam shots comprise multi-beam shots, wherein each multi-beam shot comprises a number of beamlets, and wherein the Coulomb effect depends on the number of beamlets and the dosage of each of the beamlets.

4. The method of claim 1 wherein the determining comprises revising the set of charged particle beam shots such that a dose margin of the pattern formed on the surface is increased.

5. The method of claim 1 wherein a sensitivity to variation in β

_f is reduced, for the pattern formed on the surface.

6. The method of claim 1 wherein the calculating comprises charged particle beam simulation.

7. A method for manufacturing a surface using a charged particle beam lithographic process comprising a beam blur (β

_f), the method comprising;

determining a set of charged particle beam shots that will form a desired pattern on a surface by producing a charged particle dosage on the surface,

wherein the determining comprises calculating a pattern formed on the surface, and wherein the calculating includes variation of β

_f due to Coulomb effect; and

forming the pattern on the surface with the plurality of charged particle beam shots.

8. The method of claim 7 wherein the Coulomb effect for a shot in the set of charged particle beam shots depends on an area of the shot.

9. The method of claim 7 wherein shots in the set of charged particle beam shots comprise multi-beam shots, wherein each multi-beam shot comprises a number of beamlets, and wherein the Coulomb effect depends on the number of beamlets and the dosage of each of the beamlets.

10. The method of claim 7 wherein the determining comprises revising the set of charged particle beam shots such that a dose margin of the pattern formed on the surface is increased.

11. The method of claim 7 wherein a sensitivity to variation in β

_f is reduced, for the pattern formed on the surface.

12. The method of claim 7 wherein the calculating comprises charged particle beam simulation.