Diode having trenches in a semiconductor region
An electrode structure is described in which conductive regions are recessed into a semiconductor region. Trenches may be formed in a semiconductor region, such that conductive regions can be formed in the trenches. The electrode structure may be used in semiconductor devices such as field effect transistors or diodes. Nitride-based power semiconductor devices are described including such an electrode structure, which can reduce leakage current and otherwise improve performance.
1. A diode, comprising:
a semiconductor region having trenches formed therein;
a conductive electrode forming an anode of the diode, the conductive electrode including conductive regions formed in the trenches of the semiconductor region; and
a cathode,
wherein the conductive electrode contacts the semiconductor region inside the trenches, outside the trenches, or both,
wherein the semiconductor region includes a III-N semiconductor material, and
wherein the semiconductor region is a first semiconductor region, the III-N semiconductor material is a first III-N semiconductor material, and the diode further comprises a second semiconductor region including a second III-N semiconductor material different from the first semiconductor material, wherein the first semiconductor region is between the second semiconductor region and the conductive electrode.
2. The diode of claim 1 , wherein the second III-N semiconductor material includes a GaN semiconductor material.
3. The diode of claim 1 , wherein the first semiconductor region and/or the second semiconductor region comprises a plurality of semiconductor layers.
4. The diode of claim 1 , wherein the conductive electrode includes a metal or a metal alloy.
5. The diode of claim 1 , wherein the diode further comprises an insulating region between the first semiconductor region and the conductive electrode, the insulating region extending at least partially across an interface between the first semiconductor region and the conductive electrode.
6. The diode of claim 1 , wherein the diode is a Schottky diode.
7. The diode of claim 6 , wherein a first portion of the first semiconductor region makes Schottky contact with the conductive electrode.
8. The diode of claim 7 , wherein a second portion of the first semiconductor region is separated from the conductive electrode by an insulating region.
9. The diode of claim 1 , wherein the trenches are spaced apart at periodic intervals.
10. The diode of claim 1 , wherein the conductive electrode contacts the first semiconductor region in the trenches.
11. The diode of claim 1 , wherein the conductive electrode contacts the first semiconductor region outside the trenches.
12. The diode of claim 1 , wherein the conductive electrode contacts the first semiconductor region both inside the trenches and outside the trenches.
13. The diode of claim 1 , wherein an electrode of the cathode forms an ohmic contact.
14. The diode of claim 1 , wherein the trenches extend into the second semiconductor region.
15. The diode of claim 1 , wherein the first III-N semiconductor material has a bandgap higher than that of the second III-N semiconductor material.