A FABRICATION OF NITRIDE SEMICONDUCTOR

PURPOSE: A method for manufacturing a nitride semiconductor device is provided to control a threshold voltage or a breakdown voltage by controlling the thickness and density of a low density n-type GaN layer and a p-type GaN layer. CONSTITUTION: A high density n-type GaN layer(20), a low density n-type GaN layer(30), a p-type GaN layer(40), and an n-type GaN layer(50) are successively formed on a substrate(10). A 3D structure vertically protruding from the surface of the substrate is formed by vertically etching a part of the n-type GaN layer, the p-type GaN layer, and the low density GaN layer. The upper side of the high density n-type GaN layer is exposed by etching a part of the low density n-type GaN layer. An oxide layer(60) is deposited to surround the 3D structure. A source contact(70) in contact with the upper side of the n-type GaN layer and a drain contact(80) in contact with the high density n-type GaN layer are formed.