NOVEL IN-SITU ELECTROCHEMICAL TECHNOLOGY FOR FORMATION OF OXIDE-FREE AND DEFECT-FREE SCHOTTKY CONTACT TO GAAS AND RELATED LOW-DIMENSIONAL STRUCTURES

The Pt/GaAs Schottky interfaces with excellent qualities were fabricat ed by a novel in situ electrochemical etching and plating technology u sing the electrical and photo pulses. The etched GaAs surface was very smooth, and no oxidized and disordered layer was produced at the inte rface. This technology also prevents formation of process-induced near -surface defect levels of GaAs. The Pt/GaAs diodes exhibited nearly id eal thermionic emission characteristics with a barrier height larger t han 1.0 eV and an ideality factor lower than 1.05. Selective depositio n of Schottky barriers to the edge of a two-dimensional electron gas i n a GaAs/AlGaAs quantum well structure was truly achieved by this proc ess, which is confirmed by the agreement of the experimental C-V resul ts with theoretical predictions, as well as the results of the electro n beam-induced current measurements.