CN-122028447-A - Manufacturing method of gallium nitride device

Abstract

The invention provides a manufacturing method of a gallium nitride device, which comprises the steps of sequentially forming a GaN channel layer and a barrier layer on a provided substrate layer, forming a first P-GaN layer by covering a formed structure, forming a first etching barrier layer on the first P-GaN layer, forming a second P-GaN layer on the first etching barrier layer, forming a grid metal layer by covering the formed structure, forming a pattern by a photoetching process, etching the grid metal layer to form a grid, continuing to etch downwards by taking the grid as a mask until the first etching barrier layer, forming a pattern by the photoetching process, etching the first etching barrier layer and the first P-GaN layer, forming source metal and drain metal on two sides of the rest of the first P-GaN layer, and forming a step shape between the second P-GaN layer and the first P-GaN layer on one side close to the drain metal.

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 (8)

1. 1. A method of manufacturing a gallium nitride device, comprising: s10, sequentially forming a GaN channel layer and a barrier layer on a provided substrate layer; S20, forming a first P-GaN layer by covering the formed structure, and forming a first etching barrier layer on the first P-GaN layer; s30, forming a second P-GaN layer on the first etching barrier layer; S40, forming a grid metal layer by covering the formed structure; s50, forming a pattern through a photoetching process, etching the gate metal layer to form a gate, and continuing to etch downwards by taking the gate as a mask until the first etching barrier layer; s60, forming patterns through a photoetching process, and then etching the first etching barrier layer and the first P-GaN layer, wherein the second P-GaN layer and the first P-GaN layer which remain after etching form a P-GaN region of a device; And S70, forming source electrode metal and drain electrode metal on two sides of the P-GaN region respectively, and forming a step shape between the second P-GaN layer and the first P-GaN layer on one side close to the drain electrode metal.
2. 2. The method of manufacturing a gallium nitride device according to claim 1, wherein the material of the first etching stopper layer is AlGaN or AlN.
3. 3. The method of manufacturing a gallium nitride device according to claim 1, wherein step S10 includes: Sequentially forming a GaN channel layer and a barrier layer on the provided substrate layer; And forming a second etching barrier layer on the barrier layer.
4. 4. A method of fabricating a gallium nitride device according to claim 3, wherein the material of the second etch stop layer is AlGaN or AlN.
5. 5. The method of manufacturing a gallium nitride device according to claim 1, wherein step S30 includes: Forming a second P-GaN layer on the first etching barrier layer; And forming a high-resistance layer on the second P-GaN layer.
6. 6. The method of manufacturing a gallium nitride device according to claim 5, wherein the material of the high-resistance layer is AlGaN or AlN, and the high-resistance layer has carbon or iron ion doping.
7. 7. The method of manufacturing a gallium nitride device according to claim 1, further comprising step S80: Covering the formed structure to form a first dielectric layer; A field plate is formed on the first dielectric layer between the P-GaN region and the drain metal, the field plate being located over the barrier layer and extending over the first P-GaN layer.
8. 8. The method of claim 7, wherein the first dielectric layer is silicon nitride.

Description

Manufacturing method of gallium nitride device Technical Field The invention relates to the technical field of gallium nitride devices, in particular to a manufacturing method of 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 method for manufacturing a gallium nitride device, so as to achieve an improvement in the withstand voltage level of the gallium nitride device. The invention provides a manufacturing method of a gallium nitride device, which comprises the following steps: s10, sequentially forming a GaN channel layer and a barrier layer on a provided substrate layer; S20, forming a first P-GaN layer by covering the formed structure, and forming a first etching barrier layer on the first P-GaN layer; s30, forming a second P-GaN layer on the first etching barrier layer; S40, forming a grid metal layer by covering the formed structure; s50, forming a pattern through a photoetching process, etching the gate metal layer to form a gate, and continuing to etch downwards by taking the gate as a mask until the first etching barrier layer; s60, forming patterns through a photoetching process, and then etching the first etching barrier layer and the first P-GaN layer, wherein the second P-GaN layer and the first P-GaN layer which remain after etching form a P-GaN region of a device; And S70, forming source electrode metal and drain electrode metal on two sides of the P-GaN region respectively, and forming a step shape between the second P-GaN layer and the first P-GaN layer on one side close to the drain electrode metal. Further, the material of the first etching barrier layer is AlGaN or AlN. Further, step S10 includes: Sequentially forming a GaN channel layer and a barrier layer on the provided substrate layer; And forming a second etching barrier layer on the barrier layer. Further, the material of the second etching barrier layer is AlGaN or AlN. Further, step S30 includes: Forming a second P-GaN layer on the first etching barrier layer; And forming a high-resistance layer on the second P-GaN layer. Further, the high-resistance layer is made of AlGaN or AlN, and is doped with carbon or iron ions. Further, the method further comprises step S80: Covering the formed structure to form a first dielectric layer; A field plate is formed on the first dielectric layer between the P-GaN region and the drain metal, the field plate being located over the barrier layer and extending over the first P-GaN layer. Further, the material of the first dielectric layer is silicon nitride. According to the manufacturing method of the gallium nitride device, the first etching blocking layer is arranged between the adjacent P-GaN layers, the thickness of each P-GaN layer can be accurately controlled through the growth process, and when the second P-GaN layer is etched, the second P-GaN layer is stopped when being etched until the first etching blocking layer is etched, the P-GaN layer below the second P-GaN layer can be protected from being etched, so that the formed step shape can be accurately controlled, and meanwhile, the first etching blocking layer is made of III-V group materials and is thinner, and the grid control capability of the gallium nitride device is not affected. Drawings Fig. 1-7 are schematic cross-sectional views of main process nodes of an embodiment of a method for fabricating a gallium nitride device according to the present 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 invention. It will be apparent that the