E-BLOW: E-Beam Lithography Overlapping aware Stencil Planning for MCC System

TL;DR

This paper introduces E-BLOW, a novel tool for stencil planning in multi-column cell electron beam lithography systems, addressing the NP-hard overlapping aware stencil planning problem with advanced algorithms to improve throughput.

Contribution

The paper presents E-BLOW, a new method with speedup techniques for efficient stencil planning in MCC systems, handling the NP-hard problem effectively.

Findings

E-BLOW outperforms previous methods in efficiency.

It effectively handles the NP-hard overlapping aware stencil planning problem.

Demonstrates improved throughput in MCC systems.

Abstract

Electron beam lithography (EBL) is a promising maskless solution for the technology beyond 14nm logic node. To overcome its throughput limitation, industry has proposed character projection (CP) technique, where some complex shapes (characters) can be printed in one shot. Recently the traditional EBL system is extended into multi-column cell (MCC) system to further improve the throughput. In MCC system, several independent CPs are used to further speed-up the writing process. Because of the area constraint of stencil, MCC system needs to be packed/planned carefully to take advantage of the characters. In this paper, we prove that the overlapping aware stencil planning (OSP) problem is NP-hard. To solve OSP problem in MCC system, we present a tool, E-BLOW, with several novel speedup techniques, such as successive relaxation, dynamic programming, and KD-Tree based clustering. Experimental results show that, compared with previous works, E-BLOW demonstrates better performance for both conventional EBL system and MCC system.