Semiconductor device

Abstract

In this junction element, when a forward voltage is applied, a depletion layer is formed in a semiconductor layer, prohibiting electrons present in an electrode layerto move into the semiconductor layer. For this reason, a majority of holes in a semiconductor layerdo not disappear by recombination with conduction electrons in the semiconductor layer, but reach the electrode layerwhile diffusing into the semiconductor layer. Accordingly, the junction elementcan serve as a good conductor for holes, while avoiding the influence of a resistance value, and allows a current to flow therethrough at a level equal to or more than that achieved by a semiconductor element formed of a Si or SiC semiconductor. The present invention is applicable to any semiconductor material in which at least one of a donor level and an acceptor level is located at a sufficiently deep position beyond a thermal excitation energy at an operating temperature, such as diamond, zinc oxide (ZnO), aluminum nitride (AlN), or boron nitride (BN). The present invention is also applicable to even a material having a shallow impurity level at room temperature, such as silicon (Si), silicon carbide (SiC), gallium nitride (GaN), gallium arsenide (GaAs), or germanium (Ge), as long as operation is performed at such a low temperature that the thermal excitation energy can be sufficiently small.