Patent ID: 8729558
Filing Date: 2014-05-20
Classification: H01L

Abstract:
1. A nitride semiconductor device comprising: a semiconductor layer including a nitride semiconductor; a source electrode provided on a major surface of the semiconductor layer and forming ohmic contact with the semiconductor layer; a drain electrode provided on the major surface, forming ohmic contact with the semiconductor layer and separated from the source electrode; a first gate electrode provided on the major surface between the source electrode and the drain electrode; a second gate electrode provided on the major surface between the source electrode and the first gate electrode; and an insulating layer provided between the major surface of the semiconductor layer and the first gate electrode and between the major surface of the semiconductor layer and the second gate electrode, wherein when a potential difference between the source electrode and the first gate electrode is 0 volts, a portion of the semiconductor layer under the first gate electrode is conductive, the second gate electrode is configured to receive a DC applied voltage to generate a constant DC current, the first gate electrode is configured to switch a constant current according to a voltage applied to the second gate electrode, a gate length of the second gate electrode is less than a gate length of the first gate electrode, a transconductance of the second gate electrode is more than a transconductance of the first gate electrode, and a distance between the first gate electrode and the second gate electrode is shorter than a distance between the drain electrode and the first gate electrode.