Silane and Ammonia Surface Passivation Technology for High-Mobility $\hbox {In}_{0.53}\hbox {Ga}_{0.47}\hbox {As}$ MOSFETs

We report the integration of silane and ammonia (SiH₄ + NH₃) surface passivation technology to realize high-quality gate stack on a high-mobility In_0.53Ga_0.47As compound semiconductor. Vacuum anneal at 520°C desorbs the native oxide while preserving the surface morphology and material composition of In_0.53Ga_0.47As. By incorporating SiH₄ + NH₃ passivation, a thin silicon oxynitride (SiO_xN_y) interfacial layer was formed during high-k dielectric deposition. In_0.53Ga_0.47As n-MOSFETs with SiH₄ + NH₃ passivation demonstrate significantly reduced subthreshold swing and off-state leakage current I _off in comparison with control In_0.53Ga_0.47As n-MOSFETs without passivation. This is due to significant reduction of interface state density D _it. Improvement in carrier mobility over the control In_0.53Ga_0.47As n-MOSFETs was also achieved with SiH₄ + NH₃ passivation.