Depinning of the Fermi level at the Ge Schottky interface through Se treatment

Depinning of the Fermi level at Al/Ge junctions was achieved through Se treatment. Al contacts to n- and p-type Ge with Se treatment exhibited ohmic and Schottky behaviors, respectively. During Se treatment, in addition to surface passivation by Se atoms, the chemical reaction between Se and Ge resulted in the formation of a partially ionic Se–Ge alloy film. This led to the reduction of surface states, which was responsible for the Fermi-level depinning of Ge.