Gate Stack Engineering and Thermal Treatment on Electrical and Interfacial Properties of Ti/Pt/HfO2/InAspMOS Capacitors

[摘要] Effects of gate stack engineering and thermal treatment on electrical and interfacial properties of Ti/Pt/HfO2/InAs metal insulator semiconductor (MIS) capacitors were systematically evaluated in terms of transmission electron microscopy, energy dispersive X-ray spectroscopy, current-voltage, and capacitance-voltage characterizations. A 10 nm thick Pt metal effectively suppresses the formation of interfacial oxide, TiO2, between the Ti gate and HfO2gate dielectric layer, enhancing the gate modulation on the surface potential of InAs. Anin situHfO2deposition onto then-InAs channel with an interfacial layer (IL) of one-monolayer InP followed by a 300°C post-metal-anneal produces a high-quality HfO2/InAs interface and thus unravels the annoying Fermi-level pinning, which is evidenced by the distinct capacitance dips in the high-/low-frequencyC-Vcharacteristics. The interface trap states could be further suppressed by replacing the InP IL by an As-rich InAs, which is substantiated by a gate leakage reduction and a steep voltage-dependent depletion capacitance.

[学科分类] 电子、光学、磁材料