The drive for higher magnetic storage density is correspondingly pushing to minimize the lithographic critical dimensions of the read/write components of thin film magnetic recording heads while maximizing the aspect ratio. Electron beam lithography can provide adequate resolution for research and development of magnetic heads. In this work, we present the experimental results of high aspect ratio trench patterning in 1.0-4.0 μm thick single-layer CAR resists with Leica VB6 operating at 50 keV. Although the maximum achievable aspect ratio in thick resist is limited by the forward scattering of the primary electron beam as it passes through the resist towards the resist-substrate interface, a sub-50 nm isolated top pole trench structure with an aspect ratio about 20:1 has been achieved by using e-beam SAFIER shrink process. To better understand the electron beam proximity effect on the resist profile in thick resists, electron beam simulation has been implemented. The theoretical limit of resist profiles has been predicted by simulation.

Date Published: 24 March 2006
PDF: 11 pages
Proc. SPIE 6151, Emerging Lithographic Technologies X, 61513E (24 March 2006); doi: 10.1117/12.656516

Published in SPIE Proceedings Vol. 6151:
Emerging Lithographic Technologies X
Michael J. Lercel, Editor(s)