A new figure fracturing algorithm for variable-shaped EB exposure-data generation
✍ Scribed by Hiroomi Nakao; Masayuki Terai; Koichi Moriizumi
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 392 KB
- Volume
- 83
- Category
- Article
- ISSN
- 1042-0967
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✦ Synopsis
This paper discusses a new figure fracturing algorithm to be used in input data generation for the variableshaped EB (electron beam) exposure system. In the input data generation of this kind of system, processing is required in which the individual polygons composing the mask pattern are represented as a set of trapezoids (figure fracturing). The figure fracturing considered in this paper differs from those in the conventional methods, in that the generation of a narrow trapezoid as well as the partitioning of the critical part is suppressed, in order to improve the accuracy of LSI mask fabrication. In this paper, the problem is solved as the fracturing of the composite rectangle into a set of rectangles by removing slant edges from the polygon. The relation graph is introduced to represent the relation among the partitioning line candidates. A graph-based algorithm is presented that efficiently selects the adequate partition lines from all possible candidates. The proposed method is applied to the mask fabrication for 64 M and 256 M DRAM, and a satisfactory fractured result is obtained in a practical execution time.