MOVPE growth of uniform AlGaAs and InGaAs using organoarsine with inverted-horizontal atmospheric-pressure reactor

Abstract

We have studied the MOVPE growth of GaAs, AlGaAs and InGaAs on 3 inch GaAs substrates using tertiarybutylarsine (tBAs) with an inverted horizontal atmospheric pressure reactor. The inverted reactor eliminated buoyancy-induced flow, reducing source consumption due to wall deposition. The uniformity of AlGaAs films using tBAs across a 3 inch substrate was within ± 1.2% for the donor concentration and ±0.9% for the layer thickness. We obtained high-quality selectively doped AlGaAs/GaAs heterostructures with an electron mobility of 98,000 cm 2 V -1 s -1 at 77 K for a 7 nm spacer layer. Uniform In 0.15Ga 0.85As on GaAs was obtained, but raising the InAs mole fraction, growth temperature, and V/III ratio resulted in poor uniformity. PL spectrum at 4.2 K suggests that highly pure GaAs was obtained using monoethylarsine (EAs) as well as tBAs.