Microsystem Technologies

, Volume 12, Issue 10, pp 935–939

Defect-free wet etching through pyrex glass using Cr/Au mask

Authors

  • Francis E. H. Tay
    • Department of Mechanical EngineeringNational University of Singapore
    • Institute of Bioengineering and Nanotechnology
    • Institute of Bioengineering and Nanotechnology
  • Ji Jing
    • Department of Mechanical EngineeringNational University of Singapore
  • Jianmin Miao
    • Micromachines Center, School of Mechanical and Production EngineeringNanyang Technological University
Technical paper

DOI: 10.1007/s00542-006-0116-0

Cite this article as:
Tay, F.E.H., Iliescu, C., Jing, J. et al. Microsyst Technol (2006) 12: 935. doi:10.1007/s00542-006-0116-0

Abstract

This paper reports the highest etch depth of annealed Pyrex glass achieved by wet etching in highly concentrated HF solution, using a low stress chromium–gold with assistance of photoresist as masking layer. The strategies to achieve that are: increasing the etch rate of glass and simultaneously increasing the resistance of Cr/Au mask in the etchant. By annealing the Pyrex glass and using a highly concentrated HF acid, a high etch rate can be obtained. Furthermore, a method to achieve a good resistance of the Cr/Au masking layer in the etching solution is to control the residual stress and to increase the thickness of Au deposition up to 1 μm. In addition, the presence of a hard baked photoresist can improve the etching performance. As a result, a 500-μm thick Pyrex glass wafer was etched through.

Copyright information

© Springer-Verlag 2006