CN-122028457-A - Gallium nitride device

Abstract

The invention provides a gallium nitride device which comprises a substrate layer, a GaN channel layer, a barrier layer, source metal, drain metal, a P-GaN region and a gate metal, wherein the GaN channel layer is arranged on the surface of the substrate 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, and the gate metal is arranged on the top layer P-GaN layer of the P-GaN region.

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 (9)

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; And the gate metal is positioned on the top P-GaN layer of the P-GaN region.
2. 2. The gallium nitride device of claim 1, wherein the material of the first etch stop layer is AlGaN or AlN.
3. 3. The gallium nitride device of claim 1, further comprising a second etch stop layer between the P-GaN region and the barrier layer.
4. 4. A gallium nitride device according to claim 3, wherein the material of the second etch stop layer is AlGaN or AlN.
5. 5. The gallium nitride device of claim 1, wherein the gate metal extends to one side of the drain metal over a bottom-most P-GaN layer of the P-GaN region.
6. 6. The gallium nitride device according to claim 5, wherein a dielectric layer is provided between the gate metal and a bottom-most P-GaN layer of the P-GaN region.
7. 7. The gallium nitride device of claim 6, wherein the dielectric layer is of silicon nitride or aluminum oxide.
8. 8. The gallium nitride device of claim 1, wherein adjacent P-GaN layers are stepped on a side proximate to the source metal.
9. 9. The gallium nitride device of claim 8, wherein the gate metal extends 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; And the gate metal is positioned on the top P-GaN layer of the P-GaN region. 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 gate metal extends to one side of the drain metal to above the bottommost P-GaN layer of the P-GaN region. Further, a dielectric layer is arranged between the gate metal and the bottom-most P-GaN layer of the P-GaN region. Further, the dielectric layer is made of silicon nitride or aluminum oxide. Further, the adjacent P-GaN layers are stepped on a side close to the source metal. Further, the gate metal extends to one side of the source metal to 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 dielectric layer, a gate metal, a dielectric layer and a dielectric layer, 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 the adjacent P-GaN layers, the thickness of each layer of P-GaN layer can be accurately controlled, the formed step shape can be accurately controlled, the gate metal extends to one side of a drain metal to be used as a gate field plate above the bottommost P-GaN layer of the P-GaN region, the peak electric field at the edge of the P-GaN region, which is close to one side of the drain metal, can be reduced, the withstand voltage of the gallium nitride device is improved, the gate metal extends to one side of the source metal to be above the bottommost P-GaN layer of the P-GaN region, and finally, the dielectric layer is arranged between the gate metal and the bottommost P-GaN layer of the P-GaN region, which is close to one side of the drain metal, and the gate leakage current of the gallium nitride device can be reduced, and the gate breakdown voltage can be increased. 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-sectional structure of a fourth embodiment of the gallium nitride device according to the invention. Detailed Description In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present