LOW-TEMPERATURE SURFACE CLEANING OF GAAS USING TRISDIMETHYLAMINOARSINE

We applied trisdimethylaminoarsine (TDMAAs) to the surface cleaning of GaAs (111)B substrates in a high-vacuum environment in order to lower the treatment temperature. The native oxide formed on the substrate was removed at substrate temperatures as low as 400-degrees-C under TDMAAs pressure. Characterizations by atomic force microscopy and secondary ion mass spectrometry showed that TDMAAs cleaning markedly improves the surface smoothness and reduces residual impurities (carbon and oxygen) compared to conventional thermal cleaning using As4. The photoluminescence spectra (77 K) of GaAs/AlGaAs quantum wells grown by molecular beam epitaxy directly (without a GaAs buffer layer) on a TDMAAs-cleaned substrate were comparable to those on a 500-nm-thick GaAs buffer layer after thermal cleaning.