Improvements to the alignment process in a commercial vector scan electron beam lithography tool

Docherty, K.E., Thoms, S., Dobson, P.M. and Weaver, J.M.R. (2008) Improvements to the alignment process in a commercial vector scan electron beam lithography tool. Microelectronic Engineering, 85(5-6), pp. 761-763. (doi: 10.1016/j.mee.2008.01.081)

Abstract

This paper examines the desirable properties of marker patterns for use in correlation-based alignment systems and demonstrates alignment accuracies of better than 1 nm. A framework for evaluating different classes of marker patterns has been developed and a figure of merit for marker patterns used in correlation-based alignment has been defined. We show that Penrose tilings have many desirable properties for correlation-based alignment. An alignment system based on correlation and using marker patterns derived from Penrose tilings has been developed and implemented on a commercial Vistec VB6 UHR EWF electron beam lithography tool. A new method of measuring alignment at the sub-nm level using overlaid gratings and a Fourier Transform based analysis scheme is introduced. (C) 2008 Elsevier B.V. All rights reserved

• Item Type: Articles
• Additional Information: 33rd International Conference on Micro- and Nano-Engineering Copenhagen, DENMARK, SEP 23-26, 2007
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Dobson, Dr Phil
• Authors: Docherty, K.E., Thoms, S., Dobson, P.M., and Weaver, J.M.R.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Microelectronic Engineering
• ISSN: 0167-9317