Microsystem Technologies

, Volume 7, Issue 1, pp 11–16

SU-8 as resist material for deep X-ray lithography

  • C. Cremers
  • F. Bouamrane
  • L. Singleton
  • R. Schenk

DOI: 10.1007/s005420000054

Cite this article as:
Cremers, C., Bouamrane, F., Singleton, L. et al. Microsystem Technologies (2001) 7: 11. doi:10.1007/s005420000054

Abstract

 A new negative tone resist for deep X-ray lithography is presented. This resist is a nine parts to one mixture of the EPON SU-8 resin with 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)propane (Tetrachlorobisphenol A, TCBA), the latter acting as the photoinitiator.

The resist was irradiated at the synchrotron source of DCI at LURE. It was dried for 7 to 20 days beforehand over silica gel while under a light vacuum (20 mbar). Best results for a 150 μm high resist were obtained with a X-ray bottom dose of 3 kJ cm−3 and a post exposure bake at 33 °C.

Differential Scanning Calorimetry measurements (DSC) determined the glass transition temperature of the resist. The glass transition for the undried, loose resist was 34.7 °C, and it was 28.7 °C when the resist was pressed on a silicon substrate. For a sample of the dried resist, the glass transition was 33.4 °C for the loose resist and 29.8 °C when it was pressed on a Silicon substrate.

CD measurements were made on top surface of a set of 100 μm long columns structures, which were produced in 150 μm of this resist. These structures have a constant 100 μm pitch, and the structures themselves varied in width from 20 to 17 μm. For these structures, the CD was calculated to be 0.15 ± 0.03 μm.

Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • C. Cremers
    • 1
  • F. Bouamrane
    • 1
  • L. Singleton
    • 2
  • R. Schenk
    • 2
  1. 1.Laboratoire pour l'Utilisation du Rayonnement Electromagnétique, Bâtiment 209D, Centre Universitaire Paris-Sud, B.P. 34, F-91898 Orsay Cedex, FranceFR
  2. 2.Institut für Mikrotechnik Mainz GmbH, Carl-Zeiss-Straße 18-20, D 55129 Mainz, GermanyDE