Plasma Chemistry and Plasma Processing, Vol.14, No.2, 131-150, 1994
Temperature-Dependent Dry-Etching Characteristics of III-V Semiconductors in HBr-Based and HI-Based Discharges
Microwave discharges of HBr/H-2/Ar and HI/H-2/Ar with additional dc biasing of the sample were used to etch InP. GaAs, and AlGaAs at temperatures between 50-250-degrees-C The etch rates increase by factors of 3-50 and 5-9, respectively, for HBr- and HI-based discharges over this temperature range, but display non-Arrhenius behavior. The etched surfaces became very rough above approximately 100-degrees-C for InP with either discharge chemistry due to preferential loss of P, while GaAs and AlGaAs are tolerant of the elevated temperature etching. The near-surface electrical properties of InP are severely degraded by etch temperatures above approximately 100-degrees-C, while extensive hydrogen in-diffusion occurs in GaAs and AlGaAs under these conditions, leading to dopant passivation which can he reversed by annealing at approximately 400-degrees-C.