Comparison of interfacial and electrical characteristics of HfO₂and HfAlO high-k dielectrics on compressively strained Si[sub 1−x]Ge[sub x]

Abstract

Interfacial reactions and electrical properties of HfO₂and HfAlO high-k gate dielectric films on strained Si[sub 1−x]Ge[sub x](x = 17%) fabricated by pulsed-laser deposition were investigated. The dielectric films were characterized by x-ray photoelectron spectroscopy, transmission electron microscopy, and electrical measurements. We found that alloying of HfO₂with alumina can reduce the GeO[sub x] formation at the interfacial layer and thus reduce the Ge diffusion during the film post-thermal annealing process. Such suppression effect significantly improved the electrical properties of the dielectric films.