Patent ID: 9685338
Date: 2017-06-20
CPC Classifications: H01L,H02M

Claim:
1. A method of manufacturing a compound semiconductor device, comprising: forming a compound semiconductor layered structure; forming an electrode above the compound semiconductor layered structure, the electrode having a top surface opposite the compound semiconductor layered structure, the top surface extending from a first side surface of the electrode to a second side surface of the electrode; and forming a first protective insulating film over a surface of the compound semiconductor layered structure and is made of silicon nitride as a material; wherein a recess is formed through the first protective insulating film, and a portion of the electrode is in the recess; a first portion of the electrode is formed on the first protective insulating film, the first portion including the first side surface of the electrode; the first protective insulating film includes a first region which is beneath the first portion of the electrode, the first region having a first thickness; and the first protective insulating film includes a second region where the first portion of the electrode is not over the first protective insulating film, the second region having a second thickness, wherein an upper surface of the first protective insulating film includes a step having a side surface that is coplanar to the first side surface of the electrode, and wherein the first thickness is larger than the second thickness.