Effect of photoresist-feature geometry on electron-cyclotron resonance plasma-etch reticulation of HgCdTe diodes

The factors that affect the trench width and aspect ratio in electron-cyclotron resonance (ECR) etched HgCdTe and CdTe are investigated. The ECR etch bias and anisotropy are found to be predominately determined by the photoresist feature-erosion rate. The physical characteristics of the trenches are attributed to ECR plasma-etch chemistry. A method for fabricating high aspect-ratio, HgCdTe isolation trenches is demonstrated through a combination of advanced photolithography and ECR etching.