Fermi Level Pinning and Schottky Barrier Height Control at Metal-Semiconductor Interfaces of InP and Related Materials

The present status of the various approaches to understand and control Schottky barrier heights (SBHs) on InP and related materials is reviewed. First, a brief survey on the models of Fermi level pinning is given. Then, approaches of SBH control by (1) formation of insulator interlayers, (2) formation of semiconductor interlayers, (3) sulphur and selenium surface treatments, (4) low-temperature metal deposition, (5) plasma surface treatments, and (6) electrochemical deposition are discussed from the viewpoints of the mechanism of SBH increase, the SBH values achieved, the controllability and reproducibility of the process, and the barrier reliability. A particular emphasis is placed on the in-situ electrochemical process recently developed by the author's group where Fermi level pinning seems to be removed.