Design and Development of High Performance Radiation Hardened Anti-Reflection Coatings for LWIR HgCdTe Focal Plane Arrays

摘要

High Performance LWIR Focal Plane Arrays are critical for many space applications. Reliable LWIR focal plane arrays are needed for these applications that can operate in space environment without any degradation. In this paper, we present various LWIR detector array architectures currently being evaluated for LWIR applications. These include backside-illuminated configurations for HgCdTe fabricated on CdZnTe and Silicon substrates. To optimize the LWIR device performance, minimize the anti-reflection losses, and significant reduction in the effects of solarization in space, innovative Anti-reflection coatings are needed, that will enhance the performance of the LWIR detector / focal plane arrays. We also present AR Coating models and experimental results on several promising multilayer AR coatings that includes CdTe, Si_3N_4 and diamond like Carbon, that have the necessary spectral response in the 8-14 microns and are hard materials with excellent bond strength. A combination of these materials offers the potential of developing anti-reflection coatings with high optical quality with controlled physical properties.