Inductively Coupled Plasma Etching of III‐V Nitrides in CH 4 / H 2 / Ar and CH 4 / H 2 / N 2 Chemistries

TLDR: In this article, inductively coupled plasma (ICP) etching of GaN, AlN, InN, N, InGaN, and InAlN was investigated in CH{sub 4/H{sub 2}/Ar and Ch{sub 3/N{sub 1/N} plasmas as a function of dc bias and ICP power.

Abstract: Inductively coupled plasma (ICP) etching of GaN, AlN, InN, InGaN, and InAlN was investigated in CH{sub 4}/H{sub 2}/Ar and Ch{sub 4}/H{sub 2}/N{sub 2} plasmas as a function of dc bias, ICP power, and pressure. The etch rates were generally quite low, as is common for III-nitrides in CH{sub 4}-based chemistries. In CH{sub 4}/H{sub 2}/Ar plasmas, the etch rates increased with increasing dc bias. At low radio frequency power (150 W), the etch rates increased with increasing ICP power, while at 350 W radio frequency power, a peak was found between 500 and 750 W ICP power. The dc bias was found to increase with increasing pressure. The etch rates in the CH{sub 4}/H{sub 2}/N{sub 2} chemistry were significantly lower, with a peak at 500 W ICP power. The etched surfaces were smooth, while selectivities of etch were {le} 6 for InN over GaN, AlN, InGaN, and InAlN under all conditions.