Influence of atomic-hydrogen treatment on the surface properties of n-n+ GaAs structures

Tunneling scanning electron microscopy (TSEM) has been used to study the properties of n-GaAs (100) epilayers treated in a flow of atomic hydrogen (AH). The results obtained demonstrate the effects of atomic-hydrogen treatment on the surface, which consist in etching out of the surface oxide layer, micropolishing, stabilization in relation to the alkaline environment (solution of dimethylformamide and monoethanolamine in the ratio 1:3) and oxidation, as well as a change in the surface structure due to dimer formation. It is found that treatment with atomic hydrogen leads to the formation of a thin (less than 0.05 mu m), poorly conducting surface layer, which probably greatly affects the static device parameters of Schottky-barrier diodes. (C) 1999 American Institute of Physics. [S1063-7826(99)01310-1].