ECR etching of GaP, GaAs, InP, and InGaAs in Cl(sub 2)/Ar, Cl(sub 2)/N(sub 2), BCl(sub 3)/Ar, and BCl(sub 3)/N(sub 2)

摘要

Electron cyclotron resonance (ECR) etching GaP, GaAs, InP, and InGaAs are reported as a function of percent chlorine-containing gas for Cl(sub 2)/Ar, Cl(sub 2)/N(sub 2), BCl(sub 3)/Ar, and BCl(sub 3)N(sub 2) plasma chemistries. GaAs and GaP etch rates were faster than InP and InGaAs, independent of plasma chemistry due to the low volatility of the InCl(sub x) etch products. GaAs and GaP etch rates increased as %Cl(sub 2) was increased for Cl(sub 2)/Ar and Cl(sub 2)/N(sub 2) plasmas. The GaAs and GaP etch rates were much slower in BCl(sub 3)-based plasmas due to lower concentrations of reactive Cl, however enhanced etch rates were observed in BCl(sub 3)/N(sub 2) at 75% BCl(sub 3). Smooth etched surfaces were obtained over a wide range of plasma chemistries.