Fermi-level unpinning in Pt/Al2O3/GaSb PMOS capacitors by sulphurization and rapid thermal annealing of GaSb surfaces

A facile route to mitigate the Fermi-level pinning between a p-type GaSb semiconductor and an Al2O3 dielectric is proposed. Combination of the sulphurization of the GaSb surface and the subsequent rapid thermal annealing allowed for high quality GaSb/Al2O3 interfacial characteristics; the interfacial trap density value was <= 2.0 x 10(12) cm(-2) eV(-1) in an energy range of 0.05 <= E-T - E-v <= 0.45 eV for the PMOS capacitor via rapid thermal annealing at 575 degrees C. A physical rationale was given on the basis of the thermo-chemical conversion of Ga2O into Ga2O3 and the conformal elimination of Sb related elements and oxides on the GaSb surface. Published by AIP Publishing.This study was supported by the National Research Foundation of Korea (NRF) grant funded the Korean government (NRF-2015R1A2A2A01003848) and the research fund of Hanyang University (HY-2015)