PHOTOEMISSION-STUDIES OF MG DEPOSITION ON SULFURIZED GASB(100) SURFACE

Synchrotron Radiation Photoemission Spectroscopy (SRPES) has been used to investigate the chemical states and electronic states of a [NH4]S- 2(x) treated GaSb(100) surface. We have found that the oxides of Ga an d Sb are removed and the sulfides of Ga and Sb are formed on the surfa ce. After sulfurized GaSb(100) was annealed, the Sb-S bond is broken t o form elemental Sb, while the Ga-S bonds terminate the surface, these results imply that ammonia sulfide has a passivating role for GaSb. A t room temperature (RT), deposited Mg on passivated surface has been a lso investigated. It is found that Ga atoms can be exchanged by Mg ato ms and diffuse into Mg overlayer. Moreover, the Schottky barrier heigh t of the Mg overlayer on the sulfurized GaSb surface was determined to be about 0.3 eV.