InGaAs MOS Gate Stack Formation and the MOS Interface Properties

Abstract

InGaAs MOS gate stack formation and the MOS interface control technologies, which are mandatory for realizing high performance InGaAs MOSFETs, are addressed with an emphasis on our recent achievements. Al₂O₃/InGaAs MOS gate stacks formed by Atomic Layer Deposition (ALD) are known as one of the most superior InGaAs MOS interfaces. The experimental results of Al₂O₃/InGaAs, HfO₂/InGaAs and HfO₂/Al₂O₃/InGaAs interfaces are presented. It is found that 1-nm-capaciatance equivalent thickness can be realized by HfO₂/Al₂O₃/InGaAs gate stacks. Also, semiconductor inteface buffer layers inserted between InGaAs channels and gate oxides are shown to be effective in further improving the channel mobility.