High-resolution core-level photoemission study of CF4-treated Gd2O3(Ga2O3) gate dielectric on Ge probed by synchrotron radiation

High-resolution core-level photoemission analysis using synchrotron radiation was used to investigate the superior electrical performance of aGa 2 O 3 ( Gd 2 O 3 ) gate dielectric on Ge(001) after CF 4 treatment. Prior to the treatment, a thin germanate-like oxide layer that formed at the interface prevented Ge from diffusing to the surface. The Gesurface retained a small amount of buckled dimers from the as-grown sample. The buckled dimers were quickly removed by CF 4 plasma treatment followed by an annealing process, resulting in a more uniform interface than that of the as-grown sample. The detailed interfacial electronic structure for the untreated and treated samples are presented.