Study of Multilayer TiNi Alloys as Gate Material for InGaAs NMOS Devices

• Main Authors: Tran, Duc Hoang, 陳德皇
• Other Authors: Chang, Edward Yi
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/7ytjsy

碩士 === 國立交通大學 === 材料科學與工程學系所 === 105 === For a recent year, the scaling down devices has been launched by new architecture or new materials. High efficiency and low power consumption are significantly important for electronics devices based on a new trend of electronic developments. Metal-Oxide-Semiconductor field effect transistors are concerned particularly because of its advanced properties and performance in terms of low power consumption applications. There are several considerations when studying about MOSFET such as leakage current, interface trap densities, effective work function, and interface fixed charges. This thesis focused intensely on researching the effective work function of metals. It was showed that the flat band voltage and effective work function are in a close relationship which also was inspired by previous reports on gate metals. The fact is that high effective work function metal and low effective work function metals are lead to the degradation of the oxide layer. Therefore, multilayer gate metal TiNi applied on HfO2/InGaAs MOSCAPs has been investigated. Based on electrical measurement results, the intercept of flat band voltage has increased about 0.21V from -0.1 to 0.1V after TiNi/HfO2/InGaAs MOSCAPs was annealed, and the calculated effective work function of TiNi was found approximately 4.62 eV which aligned close to the conduction band of InGaAs. This study also investigated that the amorphous phase of TiNi alloys is highly stable even in the further annealed condition at 400OC for 5 minutes and crystallized until annealed at 700OC in FG for 30 seconds. The formation of TiOxNi interfacial layer was found to prevent the further reaction of low effective work function metal Ti with O2 in HfO2 and further diffusion of high effective work function metal Ni into HfO2 layer. The study also showed that TiNi/HfO2 interface layer is much more stable than the interface layer formed by single metal.