Patent ID: 9012958
Filing Date: 2015-04-21
Classification: H01L

Abstract:
1. A semiconductor device comprising: n-type gallium nitride layer provided on a substrate; a channel layer which is provided in contact with the upper surface of the n-type gallium nitride layer and is made from a nitride semiconductor; an electron supply layer which is provided on the channel layer and is made from a nitride semiconductor; and a gate electrode, a source electrode, and a drain electrode which are provided on the electron supply layer, wherein the gate electrode is in contact with an underlying layer made from a nitride semiconductor, and the semiconductor device has a ratio defined by the following equation: where: L is the width of the gate electrode in contact with the underlying layer in a direction between the source electrode and drain electrode; and d1 is the distance between a surface of the n-type gallium nitride layer and a boundary between the gate electrode and the underlying layer.