CN-122028459-A - Gallium nitride device

Abstract

The invention provides a gallium nitride device which comprises a basal layer, a GaN channel layer, a barrier layer, source metal, drain metal, a P-GaN region and gate metal, wherein the GaN channel layer is arranged on the surface of the basal layer, the barrier layer is arranged on the surface of the GaN channel layer, the source metal and the drain metal are respectively arranged at two ends of the barrier layer, the P-GaN region is arranged above the barrier layer and between the source metal and the drain metal and is formed by stacking at least two layers of P-GaN layers, a first etching barrier layer is arranged between every two adjacent P-GaN layers, the adjacent P-GaN layers are in a step shape at one side close to the drain metal, the high-resistance layer is arranged on the topmost P-GaN layer of the P-GaN region, and the gate metal is arranged above the high-resistance layer.

Inventors

• WANG PENGFEI
• LIU LEI
• LIU WEI

Assignees

• 苏州东微半导体股份有限公司

Dates

Publication Date

20260512

Application Date

20241112

Claims (10)

1. 1. A gallium nitride device, comprising: A base layer; A GaN channel layer over the base layer; a barrier layer over the GaN channel layer; Source electrode metal and drain electrode metal located at two ends of the barrier layer respectively; The P-GaN region is positioned above the barrier layer and between the source metal and the drain metal, the P-GaN region is formed by stacking at least two layers of P-GaN layers, a first etching barrier layer is arranged between every two adjacent P-GaN layers, and the adjacent P-GaN layers are in a step shape at one side close to the drain metal; The high-resistance layer is positioned on the top-most P-GaN layer of the P-GaN region; And gate metal over the high resistance layer.
2. 2. Gallium nitride device according to claim 1, wherein the material of the high-resistance layer is AlGaN or AlN, and the high-resistance layer has carbon or iron ion doping.
3. 3. The gallium nitride device of claim 1, wherein the material of the first etch stop layer is AlGaN or AlN.
4. 4. The gallium nitride device of claim 1, further comprising a second etch stop layer between the P-GaN region and the barrier layer.
5. 5. The gallium nitride device of claim 4, wherein the material of the second etch stop layer is AlGaN or AlN.
6. 6. The gallium nitride device of claim 1, wherein the high-resistance layer and the gate metal each extend to one side of the drain metal over a bottom-most P-GaN layer of the P-GaN region.
7. 7. The gallium nitride device of claim 1, further comprising a field plate between the P-GaN region and the drain metal, the field plate being located above the barrier layer and extending above a bottom-most P-GaN layer of the P-GaN region, the field plate being isolated from the P-GaN region and the barrier layer by a dielectric layer.
8. 8. The gallium nitride device of claim 7, wherein the material of the dielectric layer is silicon nitride.
9. 9. The gallium nitride device of claim 1, wherein adjacent P-GaN layers are stepped on a side proximate to the source metal.
10. 10. The gallium nitride device of claim 9, wherein the high-resistance layer and the gate metal each extend to one side of the source metal over a bottom-most P-GaN layer of the P-GaN region.

Description

Gallium nitride device Technical Field The invention belongs to the technical field of gallium nitride devices, and particularly relates to a gallium nitride device. Background With the continuous development of semiconductor process technology, gallium nitride HEMTs (High Electron Mobility Transistor, high electron mobility transistors) have made significant progress in microwave high power. Gallium nitride HEMTs are typically depletion mode devices, i.e., when the threshold voltage Vth <0V, gate voltage vg=0v, the device is in an on state. In order to ensure circuit safety and simplify the circuit, normally off devices, i.e. enhancement devices, are preferred in practical circuit applications. The threshold voltage of the gallium nitride device adopting the P-GaN cap layer technology is easy to control, the breakdown characteristic is good, the device stability is high, and the gallium nitride device becomes the main stream technology of the enhancement type gallium nitride device on the market. However, the gallium nitride device adopting the conventional P-GaN cap layer technology still has the problems of concentrated electric lines on one side of the gate electrode, higher electric field peaks at the channel, influence on breakdown characteristics of the device, current collapse and the like. Disclosure of Invention In view of the above, an object of the present invention is to provide a gallium nitride device for improving withstand voltage of the gallium nitride device. The present invention provides a gallium nitride device comprising: A base layer; A GaN channel layer over the base layer; a barrier layer over the GaN channel layer; Source electrode metal and drain electrode metal located at two ends of the barrier layer respectively; The P-GaN region is positioned above the barrier layer and between the source metal and the drain metal, the P-GaN region is formed by stacking at least two layers of P-GaN layers, a first etching barrier layer is arranged between every two adjacent P-GaN layers, and the adjacent P-GaN layers are in a step shape at one side close to the drain metal; The high-resistance layer is positioned on the top-most P-GaN layer of the P-GaN region; And gate metal over the high resistance layer. Further, the high-resistance layer is made of AlGaN or AlN, and is doped with carbon or iron ions. Further, the material of the first etching barrier layer is AlGaN or AlN. Further, a second etch stop layer is included between the P-GaN region and the barrier layer. Further, the material of the second etching barrier layer is AlGaN or AlN. Further, the high-resistance layer and the gate metal extend to one side of the drain metal to above the bottommost P-GaN layer of the P-GaN region. Further, the semiconductor device further comprises a field plate positioned between the P-GaN region and the drain metal, the field plate is positioned on the barrier layer and extends to the bottommost P-GaN layer of the P-GaN region, and the field plate is isolated from the P-GaN region and the barrier layer by a dielectric layer. Further, the dielectric layer is made of silicon nitride. Further, the adjacent P-GaN layers are stepped on a side close to the source metal. Further, the high-resistance layer and the gate metal extend to one side of the source metal to be above the bottommost P-GaN layer of the P-GaN region. The gallium nitride device comprises a P-GaN region, a first etching blocking layer, a gate Metal, a Metal-Insulator-Semiconductor (MIS) structure, a field plate structure, a high-resistance layer, a gate Metal, a high-resistance layer and a Metal-Insulator-Semiconductor (MIS) structure, wherein the P-GaN region is formed by stacking at least two layers of P-GaN layers, the first etching blocking layer is arranged between every two adjacent P-GaN layers, the thickness of each P-GaN layer can be accurately controlled, the formed step shape can be accurately controlled, the gate Metal extends to one side of a source Metal to be above the bottommost P-GaN layer of the P-GaN region, the threshold voltage of a channel below the gate Metal can be reduced, the on-resistance of the gallium nitride device is further reduced, the field plate structure can reduce the peak electric field at the edge of the P-GaN region, which is close to one side of a drain Metal, the voltage resistance of the gallium nitride device is improved, and finally, the high-resistance layer is arranged between the gate Metal, the high-resistance layer and the MIS structure formed by the P-Insulator-Semiconductor. Drawings Fig. 1 is a schematic cross-sectional view of a first embodiment of a gallium nitride device according to the present invention; Fig. 2 is a schematic cross-sectional structure of a second embodiment of the gallium nitride device provided by the invention; Fig. 3 is a schematic cross-sectional structure of a third embodiment of a gallium nitride device according to the invention; fig. 4 is a schematic cross