| abstract |
A process is disclosed through which vias (50) can be formed by the reaction of an etchant species (52) with a mercury cadmium telluride (HgCdTe) or zinc sulfide (ZnS) layer (42). The activating gases (20) are preferably a hydrogen gas or a methane gas which is excited in a diode plasma reactor (100) which has an RF power source (13) applied to one of two parallel electrodes. The etching occurs in selected areas in a photoresist pattern (44) residing over the ZnS or HgCdTe layer (42). Wet etching the layer (42) with a wet etchant (54) following the dry etching, improves the via (50) by making the walls (48) smoother, and allowing for expansion of the vias (50) to a dimension necessary for proper operation of a HgCdTe-based infrared detector. |