In situ $H2S$ passivation of $In0.53Ga0.47As∕InP$ metal-oxide-semiconductor capacitors with atomic-layer deposited $HfO2$ gate dielectric

We have studied an in situ passivation of $In0.53Ga0.47As$⁠, based on $H2S$ exposure $(50–350°C)$ following metal organic vapor phase epitaxy growth, prior to atomic layer deposition of $HfO2$ using $Hf[N(CH3)2]4$ and $H2O$ precursors. X-ray photoelectron spectroscopy revealed the suppression of As oxide formation in air exposed InGaAs surfaces for all $H2S$ exposure temperatures. Transmission electron microscopy analysis demonstrates a reduction of the interface oxide between the $In0.53Ga0.47As$ epitaxial layer and the amorphous $HfO2$ resulting from the in situ $H2S$ passivation. The capacitance-voltage and current-voltage behavior of $Pd∕HfO2∕In0.53Ga0.47As∕InP$ structures demonstrates that the electrical characteristics of samples exposed to $50°C$ $H2S$ at the end of the metal-organic vapor-phase epitaxy $In0.53Ga0.47As$ growth are comparable to those obtained using an ex situ aqueous $(NH4)2S$ passivation.