CN-115602710-B - Gallium nitride-based diode device, preparation method and gallium nitride HEMT

Abstract

The application belongs to the technical field of semiconductors, and provides a gallium nitride-based diode device, a preparation method and a gallium nitride HEMT (high Electron mobility transistor), wherein in the gallium nitride-based diode device, a channel layer is in a convex structure, a barrier layer is arranged on a convex part of the channel layer, a first bottom dielectric layer and a second bottom dielectric layer with low dielectric constants are arranged on a base part of the channel layer and are in contact with convex parts of a cathode electrode layer and the channel layer, a first top dielectric layer and a second top dielectric layer with high dielectric constants are respectively arranged on the first bottom dielectric layer and the second bottom dielectric layer, an anode electrode layer covers the top dielectric layers and is in contact with the barrier layer, so that the electric charge quantity of the diode device is improved through the top dielectric layers, the electric field at the corners of the device is improved through the bottom dielectric layers, the breakdown voltage of a parasitic diode is improved, and the problem that the gallium nitride-based HEMT device is unstable in a high-sensitivity application scene due to the lack of a body diode is solved.

Inventors

• LIU TAO
• HUANG HUIQIN

Assignees

• 天狼芯半导体(成都)有限公司

Dates

Publication Date

20260505

Application Date

20221025

Claims (9)

1. 1. A gallium nitride-based diode device, the gallium nitride-based diode device comprising: a semiconductor substrate; the channel layer is arranged on the semiconductor substrate, and the channel layer is of a convex structure; A barrier layer provided on the raised portion of the channel layer; A first cathode electrode layer and a second cathode electrode layer, the first cathode electrode layer being provided on a left side base portion of the channel layer, the second cathode electrode layer being provided on a right side base portion of the channel layer; A first bottom dielectric layer and a second bottom dielectric layer, the first bottom dielectric layer being disposed on a left side base of the channel layer and in contact with the first cathode electrode layer and the raised portion of the channel layer, the second bottom dielectric layer being disposed on a right side base of the channel layer and in contact with the second cathode electrode layer and the raised portion of the channel layer; the first top dielectric layer is arranged on the first bottom dielectric layer and is in contact with the protruding portion of the channel layer and the barrier layer, and the second top dielectric layer is arranged on the second bottom dielectric layer and is in contact with the protruding portion of the channel layer and the barrier layer, wherein the dielectric constant of the first top dielectric layer is larger than that of the first bottom dielectric layer, and the dielectric constant of the second top dielectric layer is larger than that of the second bottom dielectric layer; The anode electrode layer is covered on the first top dielectric layer and the second top dielectric layer and is in contact with the barrier layer; The vertical part of the first top dielectric layer is arranged on the first bottom dielectric layer, and the horizontal part of the first top dielectric layer is arranged on the barrier layer; the vertical part of the second top dielectric layer is arranged on the second bottom dielectric layer, and the horizontal part of the second top dielectric layer is arranged on the barrier layer.
2. 2. A gallium nitride-based diode device according to claim 1, wherein the anode electrode layer has a T-shaped structure; the protruding portion of the anode electrode layer is arranged between the horizontal portion of the first top dielectric layer and the horizontal portion of the second top dielectric layer, and the protruding portion of the anode electrode layer is in contact with the barrier layer.
3. 3. The gallium nitride-based diode device of claim 1, wherein the horizontal portion of the first top dielectric layer is the same thickness as the horizontal portion of the second top dielectric layer.
4. 4. The gallium nitride-based diode device of claim 1, wherein a thickness of the horizontal portion of the first top dielectric layer and the horizontal portion of the second top dielectric layer is less than a thickness of the barrier layer.
5. 5. The gallium nitride-based diode device of any one of claims 1-4, wherein a thickness of the first top dielectric layer is equal to a thickness of the first bottom dielectric layer and a thickness of the second top dielectric layer is equal to a thickness of the second bottom dielectric layer.
6. 6. The gallium nitride-based diode device of any one of claims 1-4, wherein the first top dielectric layer and the second top dielectric layer are lanthanum oxide.
7. 7. A method of fabricating a gallium nitride-based diode device, comprising: sequentially forming a channel layer and a barrier layer on a semiconductor substrate; etching the channel layer and the barrier layer to enable the channel layer to be in a convex structure, wherein the barrier layer is arranged on a protruding part of the channel layer; Forming a first cathode electrode layer on a left side base portion of the channel layer and forming a second cathode electrode layer on a right side base portion of the channel layer; Forming a first bottom dielectric layer on a left side base of the channel layer and forming a second bottom dielectric layer on a right side base of the channel layer, wherein the first bottom dielectric layer is in contact with the first cathode electrode layer and the raised portion of the channel layer, and the second bottom dielectric layer is in contact with the second cathode electrode layer and the raised portion of the channel layer; forming a top dielectric layer on the first bottom dielectric layer, the second bottom dielectric layer and the barrier layer; carrying out slotting etching on the top dielectric layer to divide the top dielectric layer into a first top dielectric layer and a second top dielectric layer; Depositing an anode electrode material to cover the first top dielectric layer and the second top dielectric layer to form an anode electrode layer, wherein the anode electrode layer is in contact with the barrier layer; The vertical part of the first top dielectric layer is arranged on the first bottom dielectric layer, and the horizontal part of the first top dielectric layer is arranged on the barrier layer; the vertical part of the second top dielectric layer is arranged on the second bottom dielectric layer, and the horizontal part of the second top dielectric layer is arranged on the barrier layer.
8. 8. A gallium nitride HEMT, wherein the gallium nitride HEMT is integrated with a gallium nitride-based diode device according to any one of claims 1-6, or the gallium nitride HEMT is integrated with a gallium nitride-based diode device prepared by the preparation method according to claim 7.
9. 9. The gallium nitride HEMT of claim 8, wherein the gallium nitride-based diode device is disposed under a gate, a drain, or a source of the gallium nitride HEMT, and wherein the anode electrode layer is connected to the source of the gallium nitride HEMT and the cathode electrode layer is connected to the drain of the gallium nitride HEMT.

Description

Gallium nitride-based diode device, preparation method and gallium nitride HEMT Technical Field The application belongs to the technical field of semiconductors, and particularly relates to a gallium nitride-based diode device, a preparation method and a gallium nitride HEMT. Background Gallium nitride (GaN), as a representative of third generation semiconductor materials, has many excellent characteristics, for example, has a high critical breakdown electric field, high electron mobility, high two-dimensional electron gas concentration, good high temperature operation capability, and the like. However, in comparison to silicon-based metal oxide semiconductor field effect transistors (Si-MOSFETs), gallium nitride-based high electron mobility transistor (High Electron Mobility Transistor, HEMT) devices do not have body diodes, and the reverse current generated in high inductance application scenarios can cause device gate voltages to rise, resulting in device damage. Disclosure of Invention In order to solve the technical problems, the embodiment of the application provides a gallium nitride-based diode device, a preparation method and a gallium nitride HEMT, and aims to solve the problem that the gallium nitride-based HEMT device in the prior art is unstable in high-sensitivity application scenes due to the lack of a body diode. An embodiment of the present application provides, in a first aspect, a gallium nitride-based diode device, including: a semiconductor substrate; the channel layer is arranged on the semiconductor substrate, and the channel layer is of a convex structure; A barrier layer provided on the raised portion of the channel layer; A first cathode electrode layer and a second cathode electrode layer, the first cathode electrode layer being provided on a left side base portion of the channel layer, the second cathode electrode layer being provided on a right side base portion of the channel layer; A first bottom dielectric layer and a second bottom dielectric layer, the first bottom dielectric layer being disposed on a left side base of the channel layer and in contact with the first cathode electrode layer and the raised portion of the channel layer, the second bottom dielectric layer being disposed on a right side base of the channel layer and in contact with the second cathode electrode layer and the raised portion of the channel layer; the first top dielectric layer is arranged on the first bottom dielectric layer and is in contact with the protruding portion of the channel layer and the barrier layer, and the second top dielectric layer is arranged on the second bottom dielectric layer and is in contact with the protruding portion of the channel layer and the barrier layer, wherein the dielectric constant of the first top dielectric layer is larger than that of the first bottom dielectric layer, and the dielectric constant of the second top dielectric layer is larger than that of the second bottom dielectric layer; And the anode electrode layer is covered on the first top dielectric layer and the second top dielectric layer and is in contact with the barrier layer. In one embodiment, the first top dielectric layer and the second top dielectric layer are in an L-shaped structure; The vertical part of the first top dielectric layer is arranged on the first bottom dielectric layer, and the horizontal part of the first top dielectric layer is arranged on the barrier layer; the vertical part of the second top dielectric layer is arranged on the second bottom dielectric layer, and the horizontal part of the second top dielectric layer is arranged on the barrier layer. In one embodiment, the anode electrode layer has a T-shaped structure; the protruding portion of the anode electrode layer is arranged between the horizontal portion of the first top dielectric layer and the horizontal portion of the second top dielectric layer, and the protruding portion of the anode electrode layer is in contact with the barrier layer. In one embodiment, the horizontal portion of the first top dielectric layer is the same thickness as the horizontal portion of the second top dielectric layer. In one embodiment, the thickness of the horizontal portion of the first top dielectric layer and the horizontal portion of the second top dielectric layer is less than the thickness of the barrier layer. In one embodiment, the thickness of the first top dielectric layer is equal to the thickness of the first bottom dielectric layer, and the thickness of the second top dielectric layer is equal to the thickness of the second bottom dielectric layer. In one embodiment, the first top dielectric layer and the second top dielectric layer are lanthanum oxide. The second aspect of the embodiment of the application also provides a preparation method of the gallium nitride-based diode device, which comprises the following steps: sequentially forming a channel layer and a barrier layer on a semiconductor substrate; etching the chann