CN211789028U

CN211789028U - HEMT device

Info

Publication number: CN211789028U
Application number: CN202020181248.3U
Authority: CN
Inventors: 蔡仙清; 刘胜厚; 邹鹏辉; 卢益锋; 孙希国
Original assignee: Xiamen Sanan Integrated Circuit Co Ltd
Current assignee: Xiamen Sanan Integrated Circuit Co Ltd
Priority date: 2020-02-18
Filing date: 2020-02-18
Publication date: 2020-10-27
Anticipated expiration: 2030-02-18

Abstract

The utility model discloses a HEMT device, which at least comprises a substrate, a buffer layer, a barrier layer which are arranged in a stacking way, and a source electrode, a grid electrode and a drain electrode which are formed on the barrier layer; and a source electrode back hole extending to the source electrode is formed in the back surface of the substrate back buffer layer, a heat-conducting medium layer is filled in the source electrode back hole, and the heat-conducting medium layer does not relate to the back surface covering the substrate. It has the following advantages: effectively lower the working junction temperature of the device, reduce the thermal resistance, improve the power density of the device and improve the reliability of the device.

Description

HEMT device

Technical Field

The utility model relates to a semiconductor device especially relates to a HEMT device.

Background

Since the twenty-first century, the electronic fields such as aerospace and communication have been developed rapidly, and the first-generation semiconductor represented by Ge and Si materials and the second-generation semiconductor represented by GaAs and InSb materials have been exposed to defects and defects, and thus, the practical requirements of engineering cannot be met under special application conditions such as high power, high temperature and wide frequency band. Therefore, the third generation semiconductor materials represented by GaN-based High Electron Mobility Transistors (HEMTs) have attracted much attention due to their large forbidden bandwidth, strong breakdown electric field, high electron saturation velocity and good thermal conductivity. The thermal conductivity of GaN is second to that of SiC, and because the lattice constants of the GaN and SiC are close, the GaN material can be grown on the semi-insulating SiC material, so that the characteristic of high thermal conductivity of SiC can be fully utilized, and the temperature change caused by the self-heating effect on the power HEMT device is lower.

While the reliability and power characteristics of power HEMT devices strongly depend on the channel temperature of the device in operation. The reported single gate refers to the power density of the device which is up to 30W/mm. In multi-gate finger devices, the power density obtained is less than that of single-gate fingers. This is mainly because of thermal effects, high temperature affects output characteristics and transfer characteristics of the device, and on-resistance of the device increases with increasing temperature, degrading device performance. Device performance is strongly affected by self-heating effects. The maximum channel temperature allowed by the device determines the design of a refrigeration system, device packaging and maximum DC/RF power limitation, so that the effective reduction of the thermal resistance of the power HEMT device is particularly important.

SUMMERY OF THE UTILITY MODEL

The utility model provides a HEMT device, it has overcome in the background art the not enough of prior art, can effectively reduce the operating temperature of HEMT device.

The utility model provides a technical scheme that its technical problem adopted is:

a HEMT device at least comprises a substrate, a buffer layer, a barrier layer, a source electrode, a grid electrode and a drain electrode, wherein the substrate, the buffer layer and the barrier layer are arranged in a stacked mode; the source electrode back hole extending to the source electrode is formed in the back face of the substrate back buffer layer, metal layers are arranged in the substrate back face and the source electrode back hole, a heat conducting medium layer formed by insulating heat conducting materials is filled in the source electrode back hole, and the heat conducting medium layer does not cover the back face of the substrate.

In one embodiment: the insulating heat conduction material is a nitride material.

In one embodiment: the nitride material is aluminum nitride.

In one embodiment: the insulating heat conduction material is diamond.

In one embodiment: the HEMT device is a GaN-based HEMT device.

In one embodiment: the substrate is a SiC substrate.

In one embodiment: the buffer layer is a GaN buffer layer.

In one embodiment: the barrier layer is an AlGaN buffer layer.

Compared with the background technology, the technical scheme has the following advantages:

the heat-conducting medium layer is filled in the back hole of the source electrode of the HEMT device, so that the working temperature of the device can be favorably distributed by the heat-conducting medium layer, the working junction temperature of the device is effectively reduced, the thermal resistance is reduced, the power density of the device is improved, and the reliability of the device is improved.

Drawings

The present invention will be further explained with reference to the drawings and examples.

Fig. 1 is a schematic structural diagram of an HEMT device with improved heat dissipation performance according to this embodiment.

Detailed Description

Referring to fig. 1, an HEMT device with improved heat dissipation performance at least includes a substrate 1, a buffer layer 2, a barrier layer 3, and a source 4, a gate 5, a drain 6 and a passivation layer 7 formed on the barrier layer 3; the passivation layer is arranged among the source electrode 4, the grid electrode 5 and the drain electrode 6; a source electrode back hole 10 extending to the source electrode 4 is arranged on the back surface of the substrate 1, which faces away from the buffer layer 2, a metal layer 8 is arranged in the substrate back surface and the source electrode back hole, and two-dimensional electron gas 9 is generated between the buffer layer 2 and the barrier layer 3. The source back hole 10 is filled with a heat conducting medium layer 20, and the heat conducting medium layer 20 does not cover the back surface of the substrate 1, i.e. the back surface of the substrate 1 is free of the heat conducting medium 20. The heat conducting medium layer 20 can also play a role in flattening the source electrode back hole 10, and meanwhile, when in packaging, the solder cannot be in contact with metal in the hole, so that the influence on the metal conductivity after the solder is in contact with the metal in the hole is avoided.

The HEMT device comprises a GaN (gallium nitride) -based HEMT device, wherein a substrate 1 is a SiC (silicon carbide) substrate, a buffer layer is a GaN (gallium nitride) buffer layer, and a barrier layer is an AlGaN (gallium aluminum nitride) buffer layer.

The heat conductive medium layer 20 is formed of an insulating heat conductive material including a nitride material or diamond.

In a preferred embodiment, the thermal conductive medium layer 20 may be formed by aluminum nitride deposition. An Atomic Layer Deposition (ALD) tool may be used. AlN has high thermal conductivity, various electrical properties (dielectric constant, dielectric loss, bulk resistivity, dielectric strength and the like), good mechanical properties, can be sintered at normal pressure, and can be used for subsequent device surface mounting packaging.

The utility model discloses a pack heat-conducting medium layer 20 in the source electrode back of the body hole of HEMT device, be favorable to distributing away the operating temperature of device by heat-conducting medium layer to effective low device junction temperature of working reduces the thermal resistance, improves device power density, improves the device reliability.

The above description is only a preferred embodiment of the present invention, and therefore the scope of the present invention should not be limited by this description, and all equivalent changes and modifications made within the scope and the specification of the present invention should be covered by the present invention.

Claims

1. A HEMT device, characterized in that: the device at least comprises a substrate, a buffer layer, a barrier layer, and a source electrode, a gate electrode and a drain electrode which are stacked and formed on the barrier layer; the source electrode back hole extending to the source electrode is formed in the back face of the substrate back buffer layer, metal layers are arranged in the substrate back face and the source electrode back hole, a heat conducting medium layer formed by insulating heat conducting materials is filled in the source electrode back hole, and the heat conducting medium layer does not cover the back face of the substrate.

2. A HEMT device according to claim 1, wherein: the insulating heat conduction material is a nitride material.

3. A HEMT device according to claim 2, wherein: the nitride material is aluminum nitride.

4. A HEMT device according to claim 1, wherein: the insulating heat conduction material is diamond.

5. A HEMT device according to any one of claims 1 to 4, wherein: the HEMT device is a GaN-based HEMT device.

6. The HEMT device of claim 5, wherein: the substrate is a SiC substrate.

7. The HEMT device of claim 5, wherein: the buffer layer is a GaN buffer layer.

8. The HEMT device of claim 5, wherein: the barrier layer is an AlGaN buffer layer.