Improved interfacial and electrical properties of GaSb metal oxide semiconductor devices passivated with acidic (NH₄)₂S solution

Surface passivation with acidic (NH₄)₂S solution is shown to be effective in improving the interfacial and electrical properties of HfO₂/GaSb metal oxide semiconductor devices. Compared with control samples, the samples treated with acidic (NH₄)₂S solution show great improvements in gate leakage current, frequency dispersion, border trap density, and interface trap density. These improvements are attributed to the enhancing passivation of the substrates, according to analysis from the perspective of chemical mechanism, X-ray photoelectron spectroscopy, and high-resolution cross-sectional transmission electron microscopy.