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Title:An Algorithm for Stencil Planning in E-Beam Lithography
Author(s):Guo, Daifeng
Contributor(s):Wong, Martin D.F.
electron beam lithography
circuit design
circuit fabrication
stencil planning
Abstract:Electronic Beam Lithography (EBL) is an emerging nanolithography technology which directly writes the circuit pattern into wafer by e-beam. As an improved EBL technology, character projection (CP) has shorter manufacturing time, because it can complete a complex pattern with one electron shot by placing a stencil with pre-designed characters. On the other hand, the number of predesigned characters is limited by the area constraint of the stencil. In order to reduce the time of manufacture, it is desirable that more characters can be placed in the stencil such that fewer patterns would be written by conventional EBL. Because some blanking area around each character can be shared, we are able to arrange the characters in different orders, providing us with opportunities to reduce the total area occupied by a certain number of characters. In other words, there is an optimization problem: finding an optimal character order with smallest area given a certain blanking area and total stencil area. Previous work has shown that this problem is NP-hard, which means that it is highly unlikely to be solved by an algorithm with polynomial computational complexity. On the other hand, due to the complexity of the design, algorithms have to be executable in polynomial time. In this thesis, we focus on the one-dimensional order of characters which are basically standard cells, and give an algorithm to solve the optimal arrangement in polynomial time.
Issue Date:2012-05
Publication Status:unpublished
Peer Reviewed:not peer reviewed
Date Available in IDEALS:2014-01-09

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