Plasma-Nitrided Ga₂O₃(Gd₂O₃) as Interfacial Passivation Layer for InGaAs Metal–Oxide– Semiconductor Capacitor With HfTiON Gate Dielectric

Abstract

Plasma nitridation is used for nitrogen incorporation in Ga2O3(Gd2O3) (GGO) as interfacial passivation layer for an InGaAs metal-oxide-semiconductor capacitor with a HfTiON gate dielectric. The nitrided GGO (GGON) on InGaAs can improve the interface quality with a low interface-state density at midgap ( 1.0 × 10-12 cm-2 eV-1, and result in good electrical properties for the device, e.g., low gate leakage current ( 8.5 × 10-6 A/cm2 at Vg = 1 V), small capacitance equivalent thickness (1.60 nm), and large equivalent dielectric constant (24.9). The mechanisms involved lie in the fact that the GGON interlayer can effectively suppress the formation of the interfacial In/Ga/As oxides and remove excess As atoms on the InGaAs surface, thus unpinning the Femi level at the GGON/InGaAs interface and improving the interface quality and electrical properties of the device.