Study of surface passivation of strained indium gallium arsenide by vacuum annealing and silane treatment

Abstract

A study of the surface passivation of strained InGaAs using vacuum annealing and silane (SiH4) passivation was reported for the first time. X-ray photoelectron spectroscopy reveals the elimination of As–O bond after vacuum annealing and SiH4 surface passivation. Vacuum annealing eliminated poor quality native oxide on InGaAs surface, while a thin silicon interfacial layer was formed by SiH4 treatment, therefore effectively preventing the InGaAs surface from exposure to an oxidizing ambient during high-k dielectric deposition. Transmission electron micrograph confirmed the existence of a thin oxidized silicon layer between high-k dielectric and InGaAs. By incorporating this surface technology during gate stack formation, TaN/HfAlO/InGaAs metal-oxide-semiconductor capacitors demonstrate superior C-V characteristics with negligible frequency dispersion, small hysteresis, and interface state density as low as (3.5×1011)–(5.0×1011) cm−2 eV−1.