FLARE MAP CALCULATING METHOD AND RECORDING MEDIUM

• US 20130159944A1
• Filed: 09/14/2012
• Published: 06/20/2013
• Est. Priority Date: 12/15/2011
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Satoshi Tanaka, Taiga Uno, Toshiya Kotani
• Inventors: KOTANI, Toshiya, TANAKA, Satoshi, UNO, Taiga
• Granted Patent: US 8,527,914 B2
• Time in Patent Office: Days
• US Class Current: 716/52
• CPC Class Codes: G03F 1/70 Adapting basic layout or design of masks to lithographic process requirements, e.g., second iteration correction of mask patterns for imaging
• CPC Class Codes: G03F 7/70941 Stray fields and charges, e.g. stray light, scattered light, flare, transmission loss

Abstract

A flare map calculating method of an embodiment calculates an optical image intensity distribution in each division region set in a pattern region. Furthermore, an average value of the optical image intensity distribution is calculated in each division region. A pattern or plural patterns, which has a pattern density corresponding to the average value, is calculated as a corresponding density pattern in each division region. Furthermore, a density map, which represents a pattern density distribution within the pattern region, is generated based on the corresponding density pattern, and a flare map representing a flare intensity distribution within the pattern region is calculated by convolution integral of the density map and a point spread function.

Claims

1. A flare map calculating method comprising:

dividing a pattern region having a plurality of patterns to set a plurality of division regions in the pattern region;

performing a first exposure simulation in each of the division regions to calculate an optical image intensity distribution in each of the division regions;

calculating an average value of the optical image intensity distribution of the division regions as an average value of optical intensity distribution in each of the division regions;

generating a pattern or plural patterns, which has a pattern density corresponding to the average value of the optical intensity distribution, as a corresponding density pattern in each of the division regions;

generating a density map representing a pattern density distribution within the pattern region based on the corresponding density pattern; and

calculating a flare map representing a flare intensity distribution within the pattern region by convolution integral of the density map and a point spread function.

2. The flare map calculating method according to claim 1, wherein when generating the density map, the density map is generated in a region where the pattern region is equal to or larger than the division region.

3. The flare map calculating method according to claim 1, further comprising flare-correcting a mask pattern corresponding to the plurality of patterns by using the flare map.

4. The flare map calculating method according to claim 1, further comprising predicting an on-substrate pattern, which is formed on a substrate, by performing a second exposure simulation with respect to the plurality of patterns by using the flare map.

5. The flare map calculating method according to claim 1, wherein the plurality of patterns are design layout patterns or mask patterns.

6. The flare map calculating method according to claim 1, wherein when setting the division regions, the pattern region is divided in a mesh shape.

7. The flare map calculating method according to claim 1, wherein the first exposure simulation is performed with respect to the division regions, where patterns having a smaller size than a predetermined value are included, among the plurality of division regions, and a predefined average value of optical intensity distribution corresponding to a density value of the region is applied to the division regions, where patterns having a larger size than a predetermined value are included, among the plurality of division regions.

8. A flare map calculating method comprising:

dividing a pattern region having a plurality of patterns to set a plurality of division regions in the pattern region;

performing a first exposure simulation in each of the division regions to calculate an optical image intensity distribution in each of the division regions;

calculating an average value of the optical image intensity distribution of the division regions as an average value of optical intensity distribution in each of the division regions;

retaining correspondence information in which information indicating the average value of the optical intensity distribution is matched with each of the division regions which are two-dimensionally arrayed, as distribution information of an average value of optical intensity distribution within the pattern region; and

calculating a flare map representing a flare intensity distribution within the pattern region by convolution integral of the distribution information and a point spread function.

9. The flare map calculating method according to claim 8, wherein the distribution information of the average value of the optical intensity distribution is binary data.

10. The flare map calculating method according to claim 8, wherein the distribution information of the average value of the optical intensity distribution is pattern data defined by a GDS file or an OASIS file, and the information indicating the average value of the optical intensity distribution is retained such that the average value of the optical intensity distribution is derived from a single layer or a combination of a plurality of layers in each of the division regions.

11. The flare map calculating method according to claim 8, further comprising flare-correcting a mask pattern corresponding to the plurality of patterns by using the flare map.

12. The flare map calculating method according to claim 8, further comprising predicting an on-substrate pattern, which is formed on a substrate, by performing a second exposure simulation with respect to the plurality of patterns by using the flare map.

13. The flare map calculating method according to claim 8, wherein the plurality of patterns are design layout patterns or mask patterns.

14. The flare map calculating method according to claim 8, wherein when setting the division regions, the pattern region is divided in a mesh shape.

15. The flare map calculating method according to claim 8, wherein the first exposure simulation is performed with respect to the division regions, where patterns having a smaller size than a predetermined value are included, among the plurality of division regions, and a predefined average value of optical intensity distribution corresponding to a density value of the region is applied to the division regions, where patterns having a larger size than a predetermined value are included, among the plurality of division regions.

16. A non-transitory computer readable recording medium storing a flare map calculating program calculating a flare map on a computer, the flare map calculating program causing the computer to execute:

dividing a pattern region having a plurality of patterns to set a plurality of division regions in the pattern region;

performing an exposure simulation in each of the division regions to calculate an optical image intensity distribution in each of the division regions;

calculating an average value of the optical image intensity distribution of the division regions as an average value of optical intensity distribution in each of the division regions;

generating a pattern or plural patterns, which has a pattern density corresponding to the average value of the optical intensity distribution, as a corresponding density pattern in each of the division regions;

generating a density map representing a pattern density within the pattern region based on the corresponding density pattern; and

calculating the flare map of the pattern region by convolution integral of the density map and a point spread function.

17. The non-transitory computer readable recording medium according to claim 16, wherein when generating the density map, the density map is generated in a region where the pattern region is equal to or larger than the division region.

18. The non-transitory computer readable recording medium according to claim 16, wherein a mask pattern corresponding to the plurality of patterns is flare-corrected by using the flare map.

19. The non-transitory computer readable recording medium according to claim 16, wherein an on-substrate pattern, which is formed on a substrate, is predicted by performing a second exposure simulation with respect to the plurality of patterns by using the flare map.

20. The non-transitory computer readable recording medium according to claim 16, wherein the plurality of patterns are design layout patterns or mask patterns.