METHOD AND SYSTEM FOR FORMING A PATTERN ON A SURFACE USING MULTI-BEAM CHARGED PARTICLE BEAM LITHOGRAPHY
A method for fracturing or mask data preparation is disclosed in which a plurality of single-beam charged particle beam shots is used to create a plurality of multi-beam shots, where multi-beam exposure information is determined for each of the single-beam shots, and then the resulting multi-beam exposure information is used to generate a set of multi-beam shots. Additionally, a method for fracturing or mask data preparation is disclosed in which a plurality of single-beam shots is used to generate a set of multi-beam shots by calculating an image which the single-beam shots would form on a surface.
1 . A method for fracturing or mask data preparation of a pattern to be formed on a surface using multi-beam charged particle beam lithography, the method comprising:
inputting a set of single-beam charged particle beam shots;
calculating a calculated image using the set of single-beam charged particle beam shots; and
generating a set of multi-beam shots based on the calculated image, to convert the set of single-beam charged particle beam shots to the set of multi-beam shots which will produce a surface image on the surface, wherein the surface image matches the calculated image, within a pre-determined tolerance, and wherein the generating is performed using a computing hardware processor.
2 . The method of claim 1 wherein the pattern comprises one or more patterns, and wherein the calculated image comprises contour information for the one or more patterns.
3 . The method of claim 2 wherein the calculated image comprises dose margin information for the one or more patterns.
4 . The method of claim 1 wherein the calculated image comprises an aerial image.
5 . The method of claim 1 wherein each multi-beam shot comprises a plurality of beamlets.
6 . The method of claim 1 wherein shots in the set of single-beam charged particle beam shots comprise assigned dosages.
7 . The method of claim 1 wherein shots in the set of single-beam charged particle beam shots have no assigned dosages.
8 . The method of claim 1 wherein shots in the set of single-beam charged particle beam shots overlap.
9 . The method of claim 1 wherein shots in the set of single-beam charged particle beam shots comprise variable shaped beam (VSB) shots.
10 . The method of claim 1 wherein the calculating comprises charged particle beam simulation.
11 . The method of claim 10 wherein the charged particle beam simulation includes at least one of a group consisting of forward scattering, backward scattering, resist diffusion, Coulomb effect, fogging, loading and resist charging.
12 . The method of claim 1 wherein the pattern comprises one or more patterns, wherein the multi-beam charged particle beam lithography comprises exposing a plurality of pixels or beamlets, and wherein the step of generating comprises:
determining pixel or beamlet dosage information for each of the patterns in the one or more patterns; and
generating the set of multi-beam shots from the pixel or beamlet dosage information for the one or more patterns.
13 . A method for fracturing or mask data preparation of a pattern to be formed on a surface using multi-beam charged particle beam lithography, the method comprising:
inputting a set of single-beam charged particle beam shots;
selecting a first single-beam shot in the set of single-beam charged particle beam shots;
determining, based on the first single-beam shot, a first multi-beam exposure information which will produce an exposure which matches the first single-beam shot, within a pre-determined tolerance;
selecting a second single-beam shot in the set of single-beam charged particle beam shots;
determining, based on the second single-beam shot, a second multi-beam exposure information which will produce an exposure which matches the second single-beam shot, within the pre-determined tolerance; and
generating a set of multi-beam shots using the first multi-beam exposure information and the second multi-beam exposure information, to convert the set of single-beam charged particle beam shots to the set of multi-beam shots, wherein the set of multi-beam shots is to be used to form the pattern on the surface, wherein the generating is performed using a computing hardware processor.
14 . The method of claim 13 , wherein the first multi-beam exposure information and the second multi-beam exposure information each comprise a dosage for each of a plurality of beamlets or pixels.
15 . The method of claim 13 wherein the generating comprises:
combining the first multi-beam exposure information and the second multi-beam exposure information to create a combined multi-beam exposure information; and
determining one or more multi-beam shots which together produce the combined multi-beam exposure information.
16 . The method of claim 15 wherein the first multi-beam exposure information and the second multi-beam exposure information each comprise a dosage for each of a plurality of beamlets or pixels, and wherein the combining comprises combining dosages on a pixel-by-pixel or beamlet-by-beamlet basis.
17 . The method of claim 16 wherein dosages are combined by addition.
18 . The method of claim 13 wherein each multi-beam shot comprises a plurality of beamlets.
19 . The method of claim 13 wherein shots in the set of single-beam charged particle beam shots comprise assigned dosages.
20 . The method of claim 13 wherein shots in the set of single-beam charged particle beam shots overlap.
21 . The method of claim 13 wherein shots in the set of single-beam charged particle beam shots comprise variable shaped beam (VSB) shots.