SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To achieve a semiconductor device having the reduced contact resistance and reduced variations in characteristic value of a threshold voltage or the like by using a laminated film composed of an aluminum nitride gallium layer and a gallium nitride layer as a contact layer. SOLUTION: An active layer 13 composed of GaN and a barrier layer 14 composed of AlGaN are successively formed on a substrate 11 made of sapphire by interposing a buffer layer 12 composed of AlN. Subsequently, a mask film 15 composed of a silicon oxide or the like is formed to a region for forming a gate electrode in the upper face of the barrier layer 14. Then, the laminated film 16 is selectively formed by epitaxially growing an Al0.26Ga0.74N film with the thickness of 5.6 nm and a GaN film with the thickness of 1.4 nm alternately for seven periods by an MOCVD method. An ohmic electrode 17 is formed on the laminated film 16 after removing the mask film 15. After that, the gate electrode 18 is formed on the exposed barrier layer 14. COPYRIGHT: (C)2007,JPO&INPIT