Material selection methodology for gate dielectric material in metal-oxide-semiconductor devices

摘要

Due to the continuous scaling of metal-oxide-semiconductor (MOS) devices, SiO_2 can no longer be used as a gate dielectric, so it has to be replaced by some suitable high-κ dielectrics. As there are variety of high-κ dielectrics available to designer, so there is a need for a proper technique to select the best possible material. In this paper, we present a materials selection based on the Ashby's methodology to optimise the choice of gate dielectric material in MOS devices. In this work, performance indices and material indices have been developed for gate material in MOS devices and thereafter material selection chart is plotted. The selection chart shows that La_2O_3 is the most suitable materials followed by HfO_2 and ZrO_2 for being used as gate dielectric in MOS devices.