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

Docherty, K.E., Thoms, S. , Dobson, P. 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)

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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.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Docherty, Mr Kevin and Weaver, Professor Jonathan and Dobson, Dr Phil and Thoms, Dr Stephen
Authors: Docherty, K.E., Thoms, S., Dobson, P., 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
Published Online:02 February 2008

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