Addition of N-2 as a polymer deposition inhibitor in CH4/H-2 electrocyclotron resonance plasma etching of Hg1-xCdxTe

An approach is presented which eliminates the problems caused by hydrocarbon polymer deposition in etching compound semiconductor with CH4/H-2 based plasmas. We find that atomic nitrogen, created by the addition of N-2 to the plasma, inhibits polymer deposition in the chamber and on the sample. Atomic nitrogen has several beneficial effects; the elimination of polymer precursors, the reduction of the atomic hydrogen concentration, and a potential increase of methyl radical concentration. It is also demonstrated that the addition of N-2 to CH4/H-2 based electrocyclotron resonance plasmas used to etch HgCdTe eliminates the roughness normally formed during etching. (C) 1995 American Institute of Physics.