Passivation of GaSb using molecular beam epitaxy Y2O3 to achieve low interfacial trap density and high-performance self-aligned inversion-channel p-metal-oxide-semiconductor field-effect-transistors

Abstract

Molecular beam epitaxy deposited rare-earth oxide of Y2O3 has effectively passivated GaSb, leading to low interfacial trap densities of (1–4) × 1012 cm−2 eV−1 across the energy bandgap of GaSb. A high saturation drain current density of 130 μA/μm, a peak transconductance of 90 μS/μm, a low subthreshold slope of 147 mV/decade, and a peak field-effect hole mobility of 200 cm2/V-s were obtained in 1 μm-gate-length self-aligned inversion-channel GaSb p-Metal-Oxide-Semiconductor Field-Effect-Transistors (MOSFETs). In this work, high-κ/GaSb interfacial properties were better in samples with a high substrate temperature of 200 °C than in those with high κ's deposited at room temperature, in terms of the interfacial electrical properties, particularly, the reduction of interfacial trap densities near the conduction band and the MOSFET device performance.