Nitride semiconductor device
A nitride semiconductor device comprises: a substrate body including a conductive substrate portion and a high resistance portion; a first semiconductor layer of a nitride semiconductor provided on the substrate body; a second semiconductor layer provided on the first semiconductor layer; a first main electrode provided on the second semiconductor layer; a second main electrode provided on the second semiconductor layer; and a control electrode provided on the second semiconductor layer between the first main electrode and the second main electrode. The second semiconductor layer is made of a nondoped or n-type nitride semiconductor having a wider bandgap than the first semiconductor layer. The first main electrode is provided above the conductive portion and the second main electrode is provided above the high resistance portion.
1. A nitride semiconductor device comprising:
a substrate body including a conductive substrate portion and a high resistance portion;
a first semiconductor layer of a nitride semiconductor provided on the substrate body;
a second semiconductor layer of a nondoped or n-type nitride semiconductor having a wider bandgap than the first semiconductor layer, the second semiconductor layer being provided on the first semiconductor layer;
a first main electrode provided on the second semiconductor layer above the conductive portion;
a second main electrode provided on the second semiconductor layer above the high resistance portion; and
a control electrode provided on the second semiconductor layer between the first main electrode and the second main electrode,
wherein a distance between the control electrode and the second main electrode is larger than a sum of a thickness of the first semiconductor layer and a thickness of the second semiconductor layer.
2. A nitride semiconductor device according to claim 1 , wherein the conductive substrate portion is electrically connected to the first main electrode.
3. A nitride semiconductor device according to claim 1 , wherein the high resistance portion is filled with an insulator.
4. A nitride semiconductor device according to claim 3 , wherein the high resistance portion is made of SiO2.
5. A nitride semiconductor device according to claim 1 , wherein the conductive substrate portion is made of silicon.
6. A nitride semiconductor device according to claim 1 , wherein the high resistance portion is a cavity.
7. A nitride semiconductor device according to claim 1 , wherein the control electrode is provided above the high resistance portion.
8. A nitride semiconductor device according to claim 1 , wherein a distance between the conductive substrate portion and the second main electrode is larger than a distance between the control electrode and the second main electrode.
9. A nitride semiconductor device according to claim 8 , wherein a distance between the control electrode and the second main electrode is larger than a distance between the control electrode and the first main electrode.
10. A nitride semiconductor device comprising:
a conductive substrate portion;
a first semiconductor layer provided on the conductive substrate portion, the first semiconductor layer being made of a nitride semiconductor and having a first region into which a high resistance portion is inserted;
a second semiconductor layer of a nondoped or n-type nitride semiconductor having a larger bandgap than the first semiconductor layer, the second semiconductor layer being provided on the first semiconductor layer;
a first main electrode provided on the second semiconductor layer above a region outside the first region;
a second main electrode provided on the second semiconductor layer above the first region; and
a control electrode provided on the second semiconductor layer between the first main electrode and the second main electrode.
11. A nitride semiconductor device according to claim 10 , wherein the conductive substrate portion is electrically connected to the first main electrode.
12. A nitride semiconductor device according to claim 10 , wherein the high resistance portion is filled with an insulator.
13. A nitride semiconductor device according to claim 10 , wherein the conductive substrate portion is made of silicon.
14. A nitride semiconductor device according to claim 10 , wherein the high resistance portion is a cavity.
15. A nitride semiconductor device comprising:
a conductive substrate having a missing part;
a first semiconductor layer of a nitride semiconductor provided on the conductive substrate;
a second semiconductor layer of a nondoped or n-type nitride semiconductor having a wider bandgap than the first semiconductor layer, the second semiconductor layer being provided on the first semiconductor layer;
a first main electrode provided on the second semiconductor layer;
a second main electrode provided on the second semiconductor layer above the missing part; and
a control electrode provided on the second semiconductor layer between the first main electrode and the second main electrode.
16. A nitride semiconductor device according to claim 15 , wherein the conductive substrate is electrically connected to the first main electrode.
17. A nitride semiconductor device according to claim 15 , wherein a distance between the control electrode and the second main electrode is larger than a sum of a thickness of the first semiconductor layer and a thickness of the second semiconductor layer.
18. A nitride semiconductor device according to claim 17 , wherein a distance between the conductive substrate and the second main electrode is larger than a distance between the control electrode and the second main electrode.
19. A nitride semiconductor device according to claim 18 , wherein a distance between the control electrode and the second main electrode is larger than a distance between the control electrode and the first main electrode.