Gated AlGaN/GaN heterojunction Schottky device
View Patent ↗Some exemplary embodiments of a semiconductor device using a III-nitride heterojunction and a novel Schottky structure and related method resulting in such a semiconductor device, suitable for high voltage circuit designs, have been disclosed. One exemplary structure comprises a first layer comprising a first III-nitride material, a second layer comprising a second III-nitride material forming a heterojunction with said first layer to generate a two dimensional electron gas ( 2 DEG) within said first layer, an anode comprising at least a first metal section forming a Schottky contact on a surface of said second layer, a cathode forming an ohmic contact on said surface of said second layer, a field dielectric layer on said surface of said second layer for isolating said anode and said cathode, and an insulating material on said surface of said second layer and in contact with said anode.
1. A semiconductor device comprising:
a first layer comprising a first III-nitride material;
a second layer comprising a second III-nitride material forming a heterojunction with said first layer to generate a two dimensional electron gas (2DEG) within said first layer;
an anode comprising at least a first metal section forming a Schottky contact on a surface of said second layer;
a cathode forming an ohmic contact on said surface of said second layer;
an insulating material on said surface of said second layer and in contact with said anode;
wherein in a reverse bias mode said insulating material acts to pinch off said 2DEG in a depletion region, said depletion region being laterally spaced from said first metal section within said 2DEG.
2. The semiconductor device of claim 1 further comprising a field dielectric layer on said surface of said second layer for isolating said anode and said cathode.
3. The semiconductor device of claim 2 , wherein said field dielectric layer extends above said insulating material.
4. The semiconductor device of claim 2 , wherein a portion of said field dielectric layer is disposed between said first metal section and said insulating material.
5. The semiconductor device of claim 2 , wherein said anode extends above said field dielectric layer.
6. The semiconductor device of claim 2 , wherein said field dielectric layer is selected from the group consisting of silicon nitride and silicon oxide.
7. The semiconductor device of claim 1 , wherein said first III-nitride material comprises GaN.
8. The semiconductor device of claim 1 , wherein said second III-nitride material comprises AlGaN.
9. The semiconductor device of claim 1 , wherein said anode further comprises at least one additional metal section.
10. The semiconductor device of claim 1 , wherein said insulating material is selected from the group consisting of silicon oxide, aluminum oxide, and silicon nitride.
11. The semiconductor device of claim 1 , wherein said first metal section is selected from the group consisting of gold and nickel.
12. A semiconductor device comprising:
a first layer comprising a first III-nitride material;
a second layer comprising a second III-nitride material forming a heterojunction with said first layer to generate a two dimensional electron gas (2DEG) within said first layer;
an anode forming a Schottky contact on a surface of said second layer, a portion of said anode disposed directly on said surface of said second layer;
a cathode forming an ohmic contact with second layer;
an insulating material disposed above said surface of said second layer and in contact with said anode;
wherein in a reverse bias mode said insulating material acts to pinch off said 2DEG in a depletion region, said depletion region being laterally spaced from said portion of said anode within said 2DEG.
13. The semiconductor device of claim 12 further comprising a field dielectric layer over said surface of said second layer for isolating said anode and said cathode.
14. The semiconductor device of claim 13 , wherein said field dielectric layer extends above said insulating material.
15. The semiconductor device of claim 13 , wherein a portion of said field dielectric layer is disposed between a first metal section of said anode and said insulating material.
16. The semiconductor device of claim 13 , wherein said anode extends above said field dielectric layer.
17. The semiconductor device of claim 12 , wherein said first III-nitride material comprises GaN.
18. The semiconductor device of claim 12 , wherein said second III-nitride material comprises AlGaN.
19. The semiconductor device of claim 12 , wherein said insulating material is selected from the group consisting of silicon oxide, aluminum oxide, and silicon nitride.
20. The semiconductor device of claim 12 , wherein said anode comprises gold or nickel.