Improved characteristics for Au∕n-GaSb Schottky contacts through the use of a nonaqueous sulfide-based passivation

Abstract

The influence of nonaqueous sulfide passivation (using Na2S in the inert solvent benzene) on Au∕n-GaSb Schottky junction behavior was studied. The junction parameters, Schottky barrier height and ideality factor, were derived and compared with those of as-received GaSb surfaces as well as surfaces treated with aqueous sulfide solutions. The Schottky junction made on as-received GaSb is highly nonideal, while S-based passivation treatment of the GaSb surface before contact formation improves the rectifying behavior, and markedly reduces the reverse current. A benzene-based nonaqueous sulfide treatment results in GaSb surfaces with lower oxide and elemental antimony content than does the aqueous sulfide treatment. The produced Schottky barrier height increases to 0.61eV and the Au∕n-GaSb contact is close to an ideal Schottky junction.