METALORGANIC MOLECULAR-BEAM EPITAXY AND ETCHING OF GAAS AND GASB USING TRISDIMETHYLAMINOARSENIC AND TRISDIMETHYLAMINOANTIMONY

Metalorganic molecular beam epitaxy and etching of GaAs and GaSb using trisdimethylaminoarsenic (TDMAAs) and trisdimethylaminoantimony (TDMASb) are studied. The GaAs growth rate (GR) variation with substrate temperature (T-sub) is similar to that in the GaAs growth with TEGa (triethylgallium) and elemental As (As-4). However, the GR shows about 15% reduced values at T-sub of 500-600 degrees C and a rapid decrease above 600 degrees C. Furthermore, the etching of GaAs is observed when only the TDMAAs is supplied to the (001) GaAs surface at T-sub above 500 degrees C. On the other hand, in the case of (001) GaSb the etching of GaSb is only observed when TDMASb is supplied to the GaSb surface without precracking in spite of the simultaneous supply of TEGa, although the GaSb layers can be grown when the TDMASb is precracked at high temperatures (i.e. 620 degrees C) in the gas cracker cell. The etching effect is the common effect of both TDMAAs and TDMASb and is considered to be caused by the formation of the volatile Ga species due to the reaction of surface Ga atoms and the amine products from the TDMAAs and TDMASb.