Electrical characteristics of MOSFETs with La2O3/Y2O3 gate stack

Abstract A metal oxide semiconductor field effect transistor (MOSFET) with ultra-thin La2O3/Y2O3 high-k gate dielectric was fabricated. The effects of thermal treatment process on both physical and electrical characteristics of the La2O3/Y2O3 stack were studied using XPS and electrical measurements. It was observed that the effective mobility of the fabricated MOSFETs with La2O3/Y2O3 gate stack was not degraded with increasing the annealing temperatures up to 600 °C. X-ray photoelectron spectroscopy (XPS) analysis also revealed that the formation of SiO2 and silicate layer at the interface was suppressed in La2O3/Y2O3 stack compare to that of in La2O3 single layer. Obtained results suggesting that La2O3/Y2O3 gate stack is one of the promising candidates for high-k gate insulator to be used in the future metal oxide field effect transistors.

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