METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device capable of improving reliability.SOLUTION: A method of manufacturing a semiconductor device comprises the steps of: forming a source electrode 20 and a drain electrode 22 on a surface of a nitride semiconductor layer containing gallium; applying oxygen plasma treatment having power density of 0.2 to 0.3 W/cmto a surface of a nitride semiconductor layer 18 (cap layer) between the source electrode 20 and the drain electrode 22, after forming the source electrode 20 and the drain electrode 22, and thereby forming a conductive layer 26 having a gallium composition larger than that of the nitride semiconductor layer 18 before the oxygen plasma treatment; forming an insulating film on the upper surface of the nitride semiconductor layer after the conductive layer 26 is formed; exposing the nitride semiconductor layer 18 by removing a part of the insulating film on the conductive layer 26; and forming a gate electrode 24 on the exposed surface of the nitride semiconductor layer 18.