In situ selective etching of GaAs for improving (Al)GaAs interfaces using tris-dimethylaminoarsenic

We have investigated the in situ chemical beam etching (CBET) process of (AI)GaAs using tris-dimethylaminoarsenic (TDMAAs) within a chemical beam epitaxy chamber. The optimal CBET condition of (Al)GaAs is established, according to the analysis of atomic force microscopy, capacitance-voltage carrier profiles, and current-voltage (I-V) measurements. This CBET process using TDMAAs is shown to provide a good etching selectivity (>20) of GaAs over AlxGa1-xAs (x greater than or equal to 0.35) with a very smooth etched surface at the nanometer scale and a clean etched/regrown interface for regrowth applications. Improved I-V characteristics of etched/regrown p-n AlxGa1-xAs (x less than or equal to 0.35) junctions is also successfully demonstrated when the GaAs cap layer is preferentially etched first by TDMAAs before regrowth of AlxGa1-xAs. (C) 1997 American Institute of Physics.