Sapphire-based heterojunction half-bridge device with high heat dissipation

Abstract

The invention discloses a high-heat-dissipation sapphire-based heterojunction half-bridge device, which comprises a substrate, a low measurement region, a high measurement region, a high measurement region and a high measurement region, wherein the low measurement region consists of a first buffer layer, a first channel layer, a first heterojunction channel, a first barrier layer, a first metal source electrode, a first metal drain electrode and a first metal gate electrode; the height measurement region consists of a second buffer layer, a second channel layer, a second heterojunction channel, a second barrier layer, a second metal source electrode, a second metal drain electrode and a second metal gate electrode; the groove region consists of an insulating dielectric layer and a heat-conducting dielectric layer; according to the invention, heat in the device body is conducted out through the groove region, so that the heat dissipation performance of the device can be improved.

Description

Technical Field

[0001] The invention relates to the field of semiconductor power devices, and in particular to a sapphire-based heterojunction half-bridge device with high heat dissipation. Background Art

[0002] As one of the representatives of the third-generation wide bandgap semiconductor materials, gallium nitride has the advantages of wide bandgap, high critical breakdown electric field, high electron mobility, and high saturation electron velocity. This makes gallium nitride transistors have the characteristics of low on-resistance, high operating frequency, and fast switching speed. It has broad development prospects in the fields of high temperature, high frequency and high power, and has been widely used in the field of power devices.

[0003] At present, GaN devices mainly use sapphire, silicon and silicon carbide as substrate materials for growing epitaxial layers. Sapphire substrates are suitable for large-scale industrial production due to their high crystal quality and low cost, and are mainly used in the LED field. However, sapphire has poor thermal conductivity, and for high-power devices, the heat dissipation performance of the device is a key factor affecting the performance and reliability of the device. Therefore, improving heat dissipation capacity is an important direction for the future development of sapphire-based GaN devices. Summary of the invention

[0004] Technical problem: In response to the above problems of traditional sapphire-based gallium nitride devices, the present invention provides a sapphire-based heterojunction half-bridge device with high heat dissipation, which can effectively improve the heat dissipation performance of sapphire-based gallium nitride half-bridge devices.

[0005] Technical solution: The technical method adopted by the high heat dissipation sapphire-based heterojunction half-bridge device of the present invention is:

[0006] A substrate, a low-test region and a high-test region are provided on the upper surface of the substrate, and a groove region is provided between the low-test region and the high-test region;

[0007] The low-test region includes a first buffer layer, a first channel layer and a first barrier layer stacked from bottom to top, a first heterojunction channel with high electron mobility is generated between the first channel layer and the first barrier layer due to a polarization effect, a first metal source electrode, a first p-GaN layer and a first metal drain electrode are provided on the upper surface of the first barrier layer, and a first metal gate electrode is provided on the upper surface of the first p-GaN layer.

[0008] The high-sensing region includes a second buffer layer, a second channel layer and a second barrier layer stacked from bottom to top, a second heterojunction channel with high electron mobility is generated between the second channel layer and the second barrier layer due to a polarization effect, a second metal source electrode, a second p-GaN layer and a second metal drain electrode are arranged on the upper surface of the second barrier layer, and a second metal gate electrode is arranged on the upper surface of the second p-GaN layer.

[0009] The trench region includes an insulating medium layer and a heat conducting medium layer.

[0010] The thermal conductive medium layer in the groove region is a material with high thermal conductivity, which may be Cu, Ag, SiC or diamond.

[0011] The structure of the heat-conducting medium layer in the groove area can be a straight stripe structure, an edge groove structure, or an S-shaped structure.

[0012] The heat-conducting medium layer in the groove area is located between the low-sense area and the high-sense area.

[0013] The heat-conducting medium layer in the groove area is located between the insulating medium layer and the low-sense area and the high-sense area.

[0014] The insulating dielectric layer in the trench region is an insulating material, which may be SiO 2 、Si 3 N 4 .

[0015] Beneficial effects: Compared with the prior art, the present invention has the following beneficial effects:

[0016] Improve heat dissipation performance. The device of the present invention conducts away the heat accumulated in the channel through the heat-conducting medium layer, thereby improving the heat dissipation performance of the sapphire-based gallium nitride half-bridge device.

[0017] Improve integration. The present invention grows the upper and lower half-bridge devices of gallium nitride on the same substrate, and avoids leakage between the upper and lower half-bridges by isolating deep grooves, so that the area occupied by the half-bridge circuit is smaller, the structure is more compact, and the integration of the device is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the three-dimensional structure of a sapphire-based heterojunction half-bridge device with high heat dissipation proposed by the present invention;

[0019] Figure 2 is a two-dimensional cross-sectional schematic diagram of the sapphire-based heterojunction half-bridge device;

[0020] Figure 3 It is a schematic diagram of the three-dimensional structure of another sapphire-based heterojunction half-bridge device proposed in an embodiment of the present invention.

[0021] Figure 4 It is a schematic diagram of the three-dimensional structure of another sapphire-based heterojunction half-bridge device proposed in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation plans. It should be understood that the implementation cases described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0023] Embodiment 1:

[0024] The structure comprises: a substrate 1, a low-detection area A and a high-detection area B are arranged on the upper surface of the substrate 1, and a groove area C is arranged between the low-detection area A and the high-detection area B.

[0025] The low-test area A includes a first buffer layer 2a, a first channel layer 3a and a first barrier layer 5a stacked from bottom to top, a first heterojunction channel 4a with high electron mobility is generated between the first channel layer 3a and the first barrier layer 5a due to the polarization effect, a first metal source electrode 6a, a first p-GaN layer 7a and a first metal drain electrode 8a are provided on the upper surface of the first barrier layer 5a, and a first metal gate electrode 9a is provided on the upper surface of the first p-GaN layer 7a.

[0026] The high-sensing region B includes a second buffer layer 2b, a second channel layer 3b and a second barrier layer 5b stacked from bottom to top, a second heterojunction channel 4b with high electron mobility is generated between the second channel layer 3b and the second barrier layer 5b due to the polarization effect, a second metal source electrode 6b, a second p-GaN layer 7b and a second metal drain electrode 8b are provided on the upper surface of the second barrier layer 5b, and a second metal gate electrode 9b is provided on the upper surface of the second p-GaN layer 7b.

[0027] The trench region C includes an insulating dielectric layer 10 and a thermal conductive dielectric layer 11 .

[0028] The thermal conductive medium layer 11 in the groove region C is made of a material with high thermal conductivity, such as Cu, Ag, SiC or diamond.

[0029] The structure of the heat-conducting medium layer 11 in the groove area C is a straight strip structure.

[0030] The heat conducting medium layer 11 in the groove area C is located between the low-sensing area A and the high-sensing area B.

[0031] The heat conducting medium layer 11 in the groove area C is located between the insulating medium layer 10 and the low-sense area A and the high-sense area B.

[0032] The insulating dielectric layer 10 in the trench region C is made of insulating material, which may be SiO 2 、Si 3 N 4 .

[0033] Embodiment 2:

[0034] Based on the structure described in Example 1, in this embodiment, it is characterized in that: the heat conducting medium layer 11 is an edge groove structure, referring to Figure 3The edge of the heat-conducting medium layer is grooved to increase the surface area of ​​the heat-conducting medium layer and enhance its ability to conduct heat.

[0035] Embodiment 3:

[0036] Based on the structure described in Example 1, in this embodiment, it is characterized in that: the heat conducting medium layer 11 is an S-shaped structure, referring to Figure 3 . Increase the contact area between the thermal conductive medium layer and the insulating medium layer, and enhance its ability to conduct heat.

Claims

1. A sapphire-based heterojunction half-bridge device with high heat dissipation, the structure of which includes: A substrate (1), wherein a low-detection region (A) and a high-detection region (B) are provided on the upper surface of the substrate (1), and a groove region (C) is provided between the low-detection region (A) and the high-detection region (B). The low-sensing region (A) comprises a first buffer layer (2a), a first channel layer (3a) and a first barrier layer (5a) stacked from bottom to top; a first heterojunction channel (4a) with high electron mobility is generated between the first channel layer (3a) and the first barrier layer (5a) due to a polarization effect; a first metal source electrode (6a), a first p-GaN layer (7a) and a first metal drain electrode (8a) are provided on the upper surface of the first barrier layer (5a); and a first metal gate electrode (9a) is provided on the upper surface of the first p-GaN layer (7a). The high-sensing region (B) comprises a second buffer layer (2b), a second channel layer (3b) and a second barrier layer (5b) stacked from bottom to top; a second heterojunction channel (4b) with high electron mobility is generated between the second channel layer (3b) and the second barrier layer (5b) due to a polarization effect; a second metal source electrode (6b), a second p-GaN layer (7b) and a second metal drain electrode (8b) are provided on the upper surface of the second barrier layer (5b); and a second metal gate electrode (9b) is provided on the upper surface of the second p-GaN layer (7b). The groove area (C) comprises an insulating medium layer (10) and a heat conducting medium layer (11).

2. A sapphire-based heterojunction half-bridge device with high heat dissipation according to claim 1, characterized in that: The heat-conducting medium layer (11) in the groove area (C) is a material with high heat conductivity, which may be Cu, Ag, SiC or diamond.

3. The high heat dissipation sapphire-based heterojunction half-bridge device according to claim 1, characterized in that: The structure of the heat-conducting medium layer (11) in the groove area (C) can be a straight stripe structure, an edge groove structure, or an S-shaped structure.

4. The high heat dissipation sapphire-based heterojunction half-bridge device according to claim 1, characterized in that: The heat-conducting medium layer (11) in the groove area (C) is located between the low-sensing area (A) and the high-sensing area (B).

5. The high heat dissipation sapphire-based heterojunction half-bridge device according to claim 1, characterized in that: The heat-conducting medium layer (11) in the groove area (C) is located between the insulating medium layer (10) and the low-sensing area (A) and the high-sensing area (B).

6. The high heat dissipation sapphire-based heterojunction half-bridge device according to claim 1, characterized in that: The insulating dielectric layer (10) in the groove region (C) is made of insulating material, which may be SiO2 or Si3N4.

Images