EFFECT OF REVERSE-BIAS ANNEALING AND ZERO-BIAS ANNEALING ON A HYDROGEN-CONTAINING AU (N-TYPE GAAS) SCHOTTKY-BARRIER/

After exposure to hydrogen plasma and chemical etching to remove layer s of different thicknesses, n-type GaAs wafers with (100) and (110) or ientation were deposited with Au to form Au/(n-GaAs) Schottky barriers (SB's). After zero-bias annealing (ZBA), the Schottky barrier height (SBH) of the Au/(n-GaAs) SB's containing hydrogen falls; after reverse -bias annealing (RBA), the SBH rises; and the SBH is reversible within experimental precision in at least three ZBA-RBA processes. Furthermo re, the control effect of zero-bias annealing and reverse-bias anneali ng on the Schottky barrier height depends quantitatively on the orient ation of the GaAs wafer and the thickness of the layer removed by chem ical etching before deposition of Au. But the Schottky-barrier height of a control Schottky-barrier that is not subject to hydrogen exposure changes little during zero-bias annealing or reverse-bias annealing p rocesses. It is also found that besides the SBH the effective Richards on coefficient of the SB containing hydrogen has a one-to-one correlat ion with the reverse bias of the RBA (100 degrees C, 2 h). Experiments strongly support the fact that the hydrogen contained in the SB is es sential for the above ZBA-RBA effect. We have suggested a physical mod el to explain why hydrogen can reduce the Schottky-barrier heights and result in the ZBA-RBA effect of Au/(n-GaAs) Schottky barriers.