Impact of metal gate electrodes on electrical properties of InGaAs MOS gate stacks

Abstract

Electrical properties of Al2O3 and HfO2/InGaAs metal–oxide–semiconductor (MOS) capacitors with Al, Au and Pd gate electrodes have been evaluated in order to study the impact of metal gate electrodes on gate dielectrics and interface properties. It is found that MOS capacitors with Pd gate electrode can provide thinnest capacitance-equivalent-thickness (CET) and better HfO2/InGaAs MOS interfaces than those with Al and Au. However, the Al2O3/InGaAs interface properties are better in Au and Al gate electrodes than in Pd. Thus, the combination of high-k and gate metals must be carefully examined for realizing optimum gate stacks.