HgCdTe third-generation infrared focal plane arrays such as avalanche photodiodes, two-color detectors and multi-color detectors usually have mesa microstructures, which bring on huge challenge in device technology, especially coating resist process and exposing process. Using conventional spinning coater technology, the thickness of different position in the structure usually is incoordinate, the resist in the bottom of trench is often very thick, but the resist on the top corner of trench is often very thin, sometimes may be nothing. Spray coater technology is a new resist coating technology, which can make the resist equably distribute. The equipment we used is spin module Delta Alta Spray coater (AK 995023) produced by Suss Micro Tec. Through adjusting the parameters of the equipment, such as flux of resist, flux of nitrogen, chuck temperature, arm speed, scan times and so on, we have obtained multifarious resist figure with diverse thickness in order to satisfy different requirements. Now, we have already experimented three different mesa microstructures, the resist thickness we have obtained can change from zero point five micrometer to five micrometers. The pictures gained by scanning electronic microscope show that the resist have good uniformity, which increase the maneuverability of exposure process which we will do next.

Date Published: 8 September 2011
PDF: 7 pages
Proc. SPIE 8193, International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, 819347 (8 September 2011); doi: 10.1117/12.901034

Published in SPIE Proceedings Vol. 8193:
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications
Jeffery J. Puschell; Junhao Chu; Haimei Gong; Jin Lu, Editor(s)