Effect of Thermal Treatments on HfO₂/In_0.7Ga_0.3As Metal-Oxide-Semiconductor Capacitor Characteristics

Abstract

Post deposition annealing is a critical process for the quality improvement of gate oxides on Ⅲ-Ⅴ MOS capacitors. Though high temperature annealing would effectively repair defects, it could also induce undesired electrical characteristics due to the crystallization of the gate oxide. In this work, we investigate the novel two steps annealing technique to improve the HfO 2 /In 0.7 Ga 0.3 As MOSCAP properties. The two steps process takes advantage of 1 st high temperature annealing (550 0 C) to improve the interface quality and 2 nd low temperature annealing (450 0 C) for curing bulk oxide without oxide crystallization. The two steps annealing technique greatly improves the HfO 2 /In 0.7 Ga 0.3 As properties as compared to single step process and is expected to be helpful for future Ⅲ-Ⅴ MOSFET development. IntroductionThe IC performance improves rapidly in the past decade due to the continuous scaling of metal-oxide-semiconductor field effect transistors (MOSFET). However, as channel lengths are down to the 22nm node, conventional Si-based technology comes to the serious scaling limits. The high mobility Ⅲ-Ⅴ channel materials have attracted much attention. Among the choices of several alternative channels, In-rich InGaAs exhibits superior characteristics of high electron mobility, high saturation drift velocity, and high transconductance when used as n-channel materials (1).The lack of native oxides for Ⅲ-Ⅴ channel materials is a limitation for Ⅲ-Ⅴ MOSFET development.