Group III alkyl source purity effect on the quality of GaAs grown with tertiarybutylarsine

We have grown unintentionally doped GaAs films using tertiarybutylarsine (tBAs) or arsine reacted with clean or silicon contaminated triethylgallium. Hall and SIMS data along with photoluminescence spectra show that the silicon contaminant level in GaAs MOCVD layers grown with tBAs is higher than for layers grown using arsine. Thus, high purity in the triethylgallium source is more critical for high purity GaAs films when using tBAs than when using arsine.