Effects of annealing temperature on the characteristics of $HfSixOy/HfO2$ high-k gate oxides Available to Purchase

We have investigated the effects of annealing temperature on the physical and electrical properties of the $HfSixOy/HfO2$ thin film for high-k gate oxides in a metal-oxide-semiconductor device. The oxidation and subsequent postoxidation $N2$ annealing at 500 °C of Hf deposited directly on the Si substrate results in the $HfSixOy/HfO2$ stack layer with excellent electrical properties. For instance, we observe a negligible hysteresis window, an excellent equivalent oxide thickness (1.2 nm), and a low leakage current density $(⩽4×10−5 A/cm2$ at 2 V after compensating the flatband voltage shift). However, the formation of an interfacial $SiOx$ layer enhances as annealing temperature increases. Based on current observation, we suggest that annealing temperature must be carefully controlled to obtain the excellent electrical properties of $HfO2/HfSixOy$ high-k gate oxides.