Interface Optimization and Transport Modulation of Sm₂O₃/InP Metal Oxide Semiconductor Capacitors with Atomic Layer...

In this paper, the effect of atomic layer deposition-derived laminated interlayer on the interface chemistry and transport characteristics of sputtering-deposited Sm₂O₃/InP gate stacks have been investigated systematically. Based on X-ray photoelectron spectroscopy (XPS) measurements, it can be noted that ALD-derived Al₂O₃ interface passivation layer significantly prevents the appearance of substrate diffusion oxides and substantially optimizes gate dielectric performance. The leakage current experimental results confirm that the Sm₂O₃/Al₂O₃/InP stacked gate dielectric structure exhibits a lower leakage current density than the other samples, reaching a value of 2.87 × 10^-6 A/cm². In addition, conductivity analysis shows that high-quality metal oxide semiconductor capacitors based on Sm₂O₃/Al₂O₃/InP gate stacks have the lowest interfacial density of states (D_it) value of 1.05 × 10¹³ cm^-2 eV^-1. The conduction mechanisms of the InP-based MOS capacitors at low temperatures are not yet known, and to further explore the electron transport in InP-based MOS capacitors with different stacked gate dielectric structures, we placed samples for leakage current measurements at low varying temperatures (77-227 K). Based on the measurement results, Sm₂O₃/Al₂O₃/InP stacked gate dielectric is a promising candidate for InP-based metal oxide semiconductor field-effect-transistor devices (MOSFET) in the future.