The effect of electron cyclotron resonance plasma parameters on the aspect ratio of trenches in HgCdTe

Values of the aspect ratio for trenches etched into HgCdTe by an electron cyclotron resonance (ECR) plasma containing hydrogen and argon are limited by the phenomenon of etch lag. Modeling this plasma as an ion assisted, reactive-etching process leads to a set of conditions that greatly reduces etch lag. Use of these new process conditions produces trenches with aspect ratios greater than 3, widths less than 3 µm, and depths in excess of 15 µm.