Lithography factors that determine the aspect ratio of electron cyclotron resonance plasma etched HgCdTe trenches

Factors that affect width and aspect ratio in electron cyclotron resonance (ECR) etched HgCdTe trenches are investigated. The ECR etch bias and anisotropy are determined by photoresist feature erosion rate. The physical characteristics of the trenches are attributed to a combination of photoresist feature geometry and ECR plasma etch chemistry. This knowledge has led to production of trenches suitable for two-color, 20 µm pitch detectors.