Semiconductor devices and methods for manufacturing semiconductor devices

Abstract

The objective of this invention is to provide a semiconductor device with improved yield and a method for manufacturing the semiconductor device. The semiconductor device of this invention comprises: a substrate having a first surface and a second surface opposite to the first surface; a first nitride semiconductor layer having a third surface in contact with the second surface and a fourth surface opposite to the third surface, and a recess formed on the fourth surface; and a second nitride semiconductor layer disposed in the recess; and an opening formed in the substrate and the first nitride semiconductor layer, the opening penetrating the substrate and the first nitride semiconductor layer to reach the second nitride semiconductor layer, the second nitride semiconductor layer having a bottom surface; the semiconductor device having a first metal layer covering the inner wall of the first surface and the opening and contacting the second nitride semiconductor layer on the bottom surface; the second nitride semiconductor layer containing impurity atoms at a concentration of 1.0 × 10¹⁸ cm⁻³ or higher.