Proximity correction for electron beam lithography
Proximity correction for electron beam lithography
复制标题
电子束光刻的邻近校正
DOI：
10.1117/1.600846
复制
发表时间：
1996
影响因子：
1.3
通讯作者：
M. Peckerar
中科院分区：
文献类型：
--
作者：
C. Marrian;Steven Chang;M. Peckerar
随着电子束光刻制作掩模和直接写入所需的关键尺寸越来越小，对接近效应的校正变得越来越重要。此外，这个问题还受到电子束只能施加正能量剂量这一事实的困扰。我们讨论了诸如斩波和剂量转移等技术，这些技术已被提出以满足正性要求。另一种方法是将邻近校正视为优化问题。比较了两种方法，局部剂量校正和使用与溶液信息熵成比例的正则器进行优化。正则化近距离校正的一个显著特征是能够通过产生从特征边缘向后设置的“防火墙”来校正前向散射。随着前向散射宽度的增加，防火墙被设置在离特征边缘更远的地方。正则化优化算法使用常规技术计算时间长。然而，该算法适合于微电子集成电路协处理器的实现，它可以比最快的工作站更快地执行优化。将电路扩展到更大的像素数，最好采用混合串行/并行数字架构，该架构可以在大约1小时内纠正超过108像素的接近效应。只需添加额外的协处理器即可减少此时间。©1996美国光学学会
As the critical dimensions required in mask making and direct write by electron beam lithography become ever smaller, correction for proximity effects becomes increasingly important. Furthermore, the prob- lem is beset by the fact that only a positive energy dose can be applied with an electron beam. We discuss techniques such as chopping and dose shifting, which have been proposed to meet the positivity require- ment. An alternative approach is to treat proximity correction as an opti- mization problem. Two such methods, local area dose correction and optimization using a regularizer proportional to the informational entropy of the solution, are compared. A notable feature of the regularized prox- imity correction is the ability to correct for forward scattering by the gen- eration of a ''firewall'' set back from the edge of a feature. As the forward scattering width increases, the firewall is set back farther from the fea- ture edge. The regularized optimization algorithm is computationally time consuming using conventional techniques. However, the algorithm lends itself to a microelectronics integrated circuit coprocessor implementation, which could perform the optimization faster than even the fastest work stations. Scaling the circuit to larger number of pixels is best approached with a hybrid serial/parallel digital architecture that would correct for proximity effects over 10 8 pixels in about 1 h. This time can be reduced by simply adding additional coprocessors. © 1996 Society of Photo-Optical