QUATERNARY NITRIDE SEMICONDUCTOR POWER DEVICE AND MANUFACTURING METHOD THEREOF

摘要

A quaternary nitride power semiconductor device according to the present invention comprises: a gallium nitride buffer layer formed on a substrate; a quaternary nitride layer formed on the gallium nitride buffer layer; and a gallium nitride cap layer formed on the quaternary nitride layer. By controlling a composition ratio of the quaternary nitride layer, a polarization direction is formed to face an upper surface of the quaternary nitride layer such that secondary electron gas is formed on an upper end of the quaternary nitride layer. The quaternary nitride consists of four kinds of elements such as In, Al, Ga, and N, wherein In and Al has a predetermined composition ratio, whereby a compressive stress is applied to the quaternary nitride layer such that a polarization of the quaternary nitride layer is controlled to face an upper direction.