Ill-nitride dry etching: Comparison of inductively coupled plasma chemistries

A systematic study of the etch characteristics of GaN, AlN, and InN has been performed with boron halide- (BI3 and. BBr3) and interhalogen- (ICl and IBr) based inductively coupled plasmas. Maximum etch selectivities of similar to 100:1 were achieved for InN over both GaN and AlN in the BI3 mixtures due to the relatively high volatility of the InIx etch products and-the lower bond strength of InN. Maximum selectivities of similar to 14 for InN over GaN and <25 for InN over AlN were Obtained with ICl and IBr chemistries. The etched surface morphologies of GaN in these four mixtures are similar or better that-those of the control sample. (C) 1999 American Vacuum Society. [S0734-2101(99)18504-X].