Ion implantation for isolation of III-V semiconductors

The use of ion bombardment for the creation of resistive layers in III-V semiconductors is reviewed. There are two complementary methods to achieve the removal of free carriers in these materials. The first is to create damage-related deep levels by ion bombardment. These levels trap the charge carriers, and are not significantly thermally ionized at room temperature. The resultant high-resistivity material is stable to the temperatures at which the damage-related levels anneal out. The second method relies on implanting a species that creates a chemical deep-level state in the particular semiconductor. Thermally stable high-resistivity material is achieved at temperatures at which the implanted ion becomes electrically active. We also review the device applications in which implant isolation provides significant advantages over other techniques such as the etching of mesas.