TYPE CONVERSION OF P-(HGCD)TE USING H-2 CH4 AND AR REACTIVE ION ETCHING/

Hydrogen/methane gas mixtures and pure argon were used for reactive io n etching (RIE) of p-Hg1-xCdxTe (x approximate to 0.21 and 0.28). The effect of the H-2/CH4 ratio on the depth of the etched surface and the depth of the pn junction created under the etched surface were studie d for the H-2/CH4 RIE process. It was found that the etch depth reache s a maximum at an H-2/CH4 ratio approximate to 0.8 and the depth of th e pn junction decreases with increasing CH4 fraction in the mixture. T he roughness of the etched surface is smallest using a gas mixture wit h a small amount of H-2 (20-30%). For the pure Ar RIE process the etch and pn junction depths were studied as functions of etch time, Ar pre ssure and rf power. Clear evidence for the creation of p-n junctions u sing various kinds of Ar RIE processes is found.