Share Email Print

Proceedings Paper

Aberration correction for charged particle lithography
Author(s): Eric Munro; Xieqing Zhu; John A. Rouse; Haoning Liu
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

At present, the throughput of projection-type charge particle lithography systems, such as PREVAIL and SCALPEL, is limited primarily by the combined effects of field curvature in the projection lenses and Coulomb interaction in the particle beam. These are fundamental physical limitations, inherent in charged particle optics, so there seems little scope for significantly improving the design of such systems, using conventional rotationally symmetric electron lenses. This paper explores the possibility of overcoming the field aberrations of round electron lense, by using a novel aberration corrector, proposed by Professor H. Rose of University of Darmstadt, called a hexapole planator. In this scheme, a set of round lenses is first used to simultaneously correct distortion and coma. The hexapole planator is then used to correct the field curvature and astigmatism, and to create a negative spherical aberration. The size of the transfer lenses around the planator can then be adjusted to zero the residual spherical aberration. In a way, an electron optical projection system is obtained that is free of all primary geometrical aberrations. In this paper, the feasibility of this concept has been studied with a computer simulation. The simulations verify that this scheme can indeed work, for both electrostatic and magnetic projection systems. Two design studies have been carried out. The first is for an electrostatic system that could be used for ion beam lithography, and the second is for a magnetic projection system for electron beam lithography. In both cases, designs have been achieved in which all primary third-order geometrical aberrations are totally eliminated.

Paper Details

Date Published: 21 December 2001
PDF: 7 pages
Proc. SPIE 4510, Charged Particle Detection, Diagnostics, and Imaging, (21 December 2001); doi: 10.1117/12.451284
Show Author Affiliations
Eric Munro, Munro's Electron Beam Software Ltd. (United Kingdom)
Xieqing Zhu, Munro's Electron Beam Software Ltd. (United Kingdom)
John A. Rouse, Munro's Electron Beam Software Ltd. (United Kingdom)
Haoning Liu, Munro's Electron Beam Software Ltd. (United Kingdom)

Published in SPIE Proceedings Vol. 4510:
Charged Particle Detection, Diagnostics, and Imaging
Eric Munro; John A. Rouse, Editor(s)

© SPIE. Terms of Use
Back to Top