III-nitride power device

1. A monolithic integrated III-Nitride power device comprising:

a heterojunction III-nitride body including a first III-nitride layer, and a second III-nitride layer having a band gap different from that of said first III-nitride layer disposed over said first III-nitride layer;

a first power electrode electrically connected to said second III-nitride layer;

a second power electrode electrically connected to said second III-nitride layer;

a gate structure; and

a schottky electrode in schottky contact with said second III-nitride layer and surrounding one of said first and second power electrodes, said schottky electrode disposed between said gate structure and said one of said first and second power electrodes; and

wherein said gate structure is narrower than said schottky electrode.

2. A power device according to claim 1 , said gate structure surrounding said schottky electrode.

3. A power device according to claim 2 , wherein said gate structure includes a gate electrode and a gate insulation interposed between said heterojunction and said gate electrode.

4. A power device according to claim 3 , wherein said gate insulation is comprised of silicon dioxide.

5. A power device according to claim 3 , wherein said gate insulation is comprised of silicon nitride.

6. A power device according to claim 1 , wherein said first III-nitride layer is comprised of GaN and said second III-nitride layer is comprised of AlGaN.

7. A power device according to claim 1 , wherein said first III-nitride layer is comprised of one alloy of from the InAlGaN system and said second III-nitride layer is comprised of another alloy from the InAlGaN system having a band gap that is different from that of said one alloy.

8. A power device according to claim 1 , wherein said first power electrode and said second power electrode make ohmic contact with said second III-nitride layer.

9. A power device according to claim 1 , wherein said electrode surrounded by said schottky electrode is the drain electrode.

10. A power device according to claim 1 , wherein said schottky electrode is biased to a voltage.

11. A power device according to claim 1 , further comprising at least one field plate ring disposed around said one of said electrodes and between said one of said electrodes and said schottky electrode.

12. A power device according to claim 1 , wherein said schottky electrode is surrounding and spaced from said one of said first and second power electrodes.

13. A III-Nitride device comprising:

a heterojunction III-nitride body including a first III-nitride layer, and a second III-nitride layer having a band gap different from that of said first III-nitride layer disposed over said first III-nitride layer;

a source electrode electrically connected to said second III-nitride layer;

a drain electrode electrically connected to said second III-nitride layer;

a gate structure; and

a schottky electrode in schottky contact with said second III-nitride layer and surrounding and spaced from said drain electrode, said schottky electrode disposed between said gate structure and said drain electrode; and

wherein said gate structure is narrower than said schottky electrode.

14. A device according to claim 13 , said gate structure surrounding said schottky electrode.

15. A device according to claim 14 , wherein said gate structure includes a gate electrode and a gate insulation interposed between said heterojunction and said gate electrode.

16. A device according to claim 13 , wherein said first III-nitride layer is comprised of one alloy of from the InAlGaN system and said second III-nitride layer is comprised of another alloy from the InAlGaN system having a band gap that is different from that of said one alloy.

17. A device according to claim 13 , wherein said source electrode and said drain electrode make ohmic contact with said second III-nitride layer.

18. A device according to claim 13 , wherein said schottky electrode is biased to a voltage.

19. A device according to claim 13 , wherein said schottky electrode is shorted to said source electrode.

20. A device according to claim 13 , further comprising at least one field plate ring disposed around said drain electrode and between said drain electrode and said schottky electrode.