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 (Al)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 Al_xGa_1-xAs (x≥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 Al_xGa_1-xAs (x≤0.35) junctions is also successfully demonstrated when the GaAs cap layer is preferentially etched first by TDMAAs before regrowth of Al_xGa_1-xAs.© 1997 American Institute of Physics.