An improved method for Hg1−xCdxTe surface chemistry characterization

Hg1−xCdxTe surface chemistry has been studied extensively with well-known tools such as electron spectroscopy for chemical analysis (ESCA) and Auger electron spectroscopy (AES) in order to advance detector array operability, performance, and yield. Raytheon Vision Systems has pioneered the first application of time-of-flight secondary ion mass spectrometry (TOF-SIMS) as a Hg1−xCdxTe surface diagnostic tool to provide unprecedented analysis capability, including analyzing a 0.5-µm-diameter spot, high mass resolution, elemental and molecular composition scrutiny, applicability to insulators, and surface film sensitivity in the part per million range. In this study, data are presented illustrating surface chemistry geometry effects and photoresist redeposition due to common Hg1−xCdxTe processing steps including photolithography, bromine etching, and photoresist stripping.