Chemical modification and characterization of Te-doped n-GaSb (111) single crystals for device application

Ru+3 and Pt+4 modification showed considerable improvement in the surface properties of Te-doped n-GaSb (111) single crystals. The surface carrier concentration (Ns) decreased from 1.24×1017 to 0.42×1017 cm−3 after modification and the surface mobility (μs) increased from 510.86 to 734.56 cm2 V−1 s−1. Au/n-GaSb Schottky diodes prepared after Ru+3 and Pt+4 treatment of GaSb surface showed considerable increase in barrier height (Vs) from 0.55 to 0.68 eV. The dark current density (Jo) decreased from 3.2×10−3 to 8×10−4 A/cm2, and the ideality factor (n) decreased from 3 to 1.54. Although Pt+4 treatment also improved the GaSb surface, treatment with Ru+3 produced superior results. Ru+3 and Pt+4 treatment effectively decreased the etch pit density considerably.