CN111900140A - High-efficiency heat-dissipation gallium nitride transistor based on diamond passivation structure and manufacturing method thereof - Google Patents

Abstract

The invention discloses a high-efficiency heat-dissipation gallium nitride transistor based on a diamond passivation structure and a manufacturing method thereof, wherein the high-efficiency heat-dissipation gallium nitride transistor sequentially comprises the diamond passivation layer, a gate source drain functional layer, a barrier layer, a buffer layer and a substrate from top to bottom; the diamond passivation layer is of a multilayer structure, comprises a potential barrier protection layer, a seed layer and a heat conduction layer, has a high heat conduction effect, and effectively reduces the junction temperature of the gallium nitride transistor; the method for realizing the high-efficiency heat dissipation gallium nitride transistor based on the diamond passivation structure adopts a low-temperature diamond growth passivation technology to solve the compatibility with the traditional process of devices. The gallium nitride-based device with the diamond passivation structure has the advantage of high-efficiency heat dissipation capability, and can be used for ultrahigh-power microwave power devices.

Description

High-efficiency heat dissipation gallium nitride transistor based on diamond passivation structure and its manufacturing method

technical field

The invention belongs to the research field of thermal management technology of novel semiconductor devices, in particular to a high-efficiency heat dissipation gallium nitride transistor based on a diamond passivation structure and a manufacturing method thereof.

Background technique

The third-generation semiconductor power devices represented by gallium nitride have shown their excellent high-power application characteristics. The power density of gallium nitride devices in practical applications only reaches 3-8W/mm, which is far lower than its theoretical The high-power characteristic advantage of GaN is far from being brought into play. This is mainly because gallium nitride devices will generate a lot of heat accumulation while outputting high power. The greater the power, the more serious the heat accumulation will be. The heat accumulation will lead to an increase in the junction temperature of the gallium nitride transistor core, which will sharply increase the performance and reliability of the device. attenuation. At present, the thermal conductivity of GaN-based power devices cannot meet the development of high-power devices due to the thermal conductivity of their own materials, and the heat dissipation problem severely limits the performance of GaN-based devices. The main technical bottleneck of power application. Therefore, exploring the thermal management method for the integration of high thermal conductivity materials and GaN devices near the junction region will be the main way and research hotspot to solve the heat accumulation of GaN devices and adapt to its high power.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a high-efficiency heat dissipation gallium nitride transistor based on a diamond passivation structure and a manufacturing method thereof, to solve the problem of heat accumulation in the active area of gallium nitride power device chips, to develop chip-level thermal management technology, and to improve nitrogen output characteristics and reliability of GaN devices.

The technical solution to achieve the purpose of the present invention is: a high-efficiency heat dissipation gallium nitride transistor based on a diamond passivation structure, the structure design includes a diamond passivation layer, a gate-source-drain functional layer, a potential barrier layer, a buffer layer from top to bottom in order Layer and substrate, the diamond passivation layer is a multi-layer structure, including a barrier protection layer, a seed layer and a heat conduction layer.

Further, the material of the barrier protection layer is SiN or AlN medium with a thickness of 10-30 nanometers, the material of the seed layer is a carbon-based medium with a thickness of 10-50 nanometers, and the thermal conductive layer is a diamond medium with a thickness of 400-600 nanometers.

Further, the diamond passivation layer adopts a step-by-step, low-temperature growth process, firstly growing the barrier protective layer medium, then growing the seed layer material, and finally growing the thermal conductive layer material.

A method for manufacturing a high-efficiency heat dissipation gallium nitride transistor based on a diamond passivation structure, comprising the following steps:

1) Preparation of source and drain functional regions: the growth of source and drain functional regions;

2) Diamond passivation preparation: First, the CVD process is used to grow the barrier protective layer, the thickness of the potential protective layer is 10-30 nanometers, and the material is SiN or AlN medium; secondly, the seed layer is grown, and the thickness of the seed layer is 10-50 nm. Nanometer carbon-based medium; finally, CVD technology is used to grow the diamond thermal conductive layer, the thickness of the thermal conductive layer is 400-600 nanometers, and the growth temperature is not higher than 750 °C;

3) gate area diamond etching: carry out the etching of the diamond passivation layer to realize the preparation of the gate area of the gallium nitride functional layer;

4) Gate metal growth: The gate metal is grown by the gate process to prepare the gate metal of the gallium nitride functional layer. The thickness of the gate metal is 50-100 nanometers larger than that of the diamond passivation layer;

5) Diamond etching in the source and drain regions: etching the diamond passivation layer to realize the preparation of the source-drain thickening interconnection region of the gallium nitride functional layer;

6) Interconnection preparation of source and drain functional regions: The thickening interconnection of source and drain functional regions is carried out by using gold evaporation growth process, and the total thickness of source and drain diamond passivation layer is 50-100 nanometers thick; Thermal GaN transistor fabrication.

Further, in step 3) and step 5), photolithography and ICP process are used to etch the diamond passivation layer.

Compared with the prior art, the present invention has significant advantages as follows: the present invention utilizes CVD technology to conduct diamond passivation growth on gallium nitride transistors, and realizes the preparation of diamond gate regions by multi-step etching technology. A high thermal conductivity diamond heat dissipation layer is formed on the upper surface of the gallium nitride transistor, so as to realize the development of new technology of chip-level thermal management of gallium nitride transistors, improve the heat dissipation capability of the near junction area of gallium nitride transistors, and solve the problem of heat accumulation; (2) the present invention will The high thermal conductivity diamond material is integrated into the gallium nitride chip, which improves the heat dissipation capability of the near-junction area on the chip. Compared with the traditional gallium nitride device, the thermal resistance of the device can be reduced by more than 20%, which solves the problem of the active area of the gallium nitride device. The heat accumulation greatly improves the reliability of the device.

Description of drawings

FIG. 1 is a schematic structural diagram of a high-efficiency heat dissipation gallium nitride transistor device based on a diamond passivation structure of the present invention.

2 includes FIG. 2a, FIG. 2b, FIG. 2c, FIG. 2d, FIG. 2e, and FIG. 2f, and is a schematic diagram of the process flow of the design and manufacturing method of a high-efficiency heat dissipation gallium nitride transistor based on a diamond passivation structure proposed by the present invention.

Detailed ways

The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

Referring to FIG. 1 , a high-efficiency heat-dissipating gallium nitride transistor based on a diamond passivation structure and a manufacturing method proposed by the present invention, the high-efficiency heat-dissipating gallium nitride transistor structure design includes a diamond passivation layer 3, a source-drain gate sequentially from top to bottom Functional layers 1 , 2 , 4 , barrier layer 5 , buffer layer 6 and substrate 7 . The diamond passivation layer 3 is a multi-layer structure, including a potential barrier protection layer, a seed layer and a thermal conduction layer, which has a high thermal conductivity and effectively reduces the junction temperature of the gallium nitride transistor. The material of the barrier protection layer is SiN or AlN medium with a thickness of 10-30 nanometers, the material of the seed layer is a carbon-based medium with a thickness of 10-50 nanometers, and the thermal conductive layer is a diamond medium with a thickness of 400-600 nanometers. The high-efficiency heat dissipation gallium nitride transistor substrate 7 is any one of Si, sapphire and SiC materials, the buffer layer 6 is a GaN material, and the potential barrier layer is an AlGaN material;

Referring to FIG. 2 , a method for manufacturing a high-efficiency heat-dissipating gallium nitride transistor based on a diamond passivation structure of the present invention, the compatibility between the traditional process of the transistor and the diamond passivation growth is solved by the following steps:

1) Preparation of source-drain functional regions: The functional regions of source 1-1 and drain 2-1 are grown using traditional processes, as shown in Figure 2a;

2) Diamond passivation preparation: firstly, the CVD process is used to grow the barrier protection layer 3-1, the thickness of the potential protection layer is 10-30 nanometers, and the material is SiN or AlN medium; secondly, the seed layer 3-2 is grown, and the seed layer is A carbon-based medium with a thickness of 10-50 nanometers; finally, CVD technology is used to grow the diamond thermal conductive layer 3-3, the thermal conductive layer thickness is 400-600 nanometers, and the growth temperature is not higher than 750 °C; as shown in Figure 2b;

3) gate area diamond etching: use photolithography, ICP and other processes to etch the diamond passivation layer to realize the preparation of the gate area 4-1 of the gallium nitride functional layer, as shown in Figure 2c;

4) Gate metal growth: The traditional gate process is used to grow, and the gate metal 4 of the gallium nitride functional layer is prepared. The thickness of the gate metal is 50-100 nanometers larger than that of the diamond passivation layer, as shown in Figure 2d;

5) Diamond etching in the source and drain regions: The diamond passivation layer is etched by photolithography and ICP processes to realize the preparation of the source-drain thickening interconnection regions 1-2 and 2-2 of the gallium nitride functional layer, such as As shown in Figure 2e;

6) Interconnection preparation of source and drain functional regions: The traditional gold evaporation growth process is used to thicken the interconnection of source 1 and drain 2 functional regions, and the total thickness of source and drain diamond passivation layer thickness is 50-100 nanometers, as shown in Figure 2f ; Complete the manufacture of high-efficiency heat dissipation GaN transistors based on diamond passivation structure.

The present invention will be described in detail below with reference to the embodiments.

Example

A method for designing and manufacturing a high-efficiency heat-dissipating gallium nitride transistor based on a diamond passivation structure, specifically comprising:

1) Based on GaN epitaxial materials, the source and drain functional regions are grown by traditional source and drain evaporation processes, with a thickness of 200 nanometers;

2) First, the CVD process is used to grow the SiN barrier protection layer, and the thickness of SiN is 20 nanometers; secondly, the nanocarbon-based seed layer is grown with a thickness of 20 nanometers; finally, the CVD technology is used to grow the diamond thermal conductive layer, and the growth thickness is 460 nanometers. , the growth temperature is 740℃;

3) The designed gate length is 0.4 microns, and the diamond passivation layer is etched by photolithography and ICP, and the etching gas is oxygen and argon to complete the preparation of the gate region of the gallium nitride functional layer;

4) The traditional gate process is used to grow, and the gate metal of the gallium nitride functional layer is prepared, and the thickness of the gate metal is 550 nanometers;

5) The diamond passivation layer on the source and drain is etched by traditional lithography and ICP processes. The etching gas is oxygen and argon. The etching area is consistent with the size of the source and drain. Preparation of thick interconnect regions;

6) Finally, the traditional gold evaporation growth process is used to thicken the interconnection of the source and drain functional regions. The thickened metal thickness of the interconnection is 350 nanometers, and the total thickness of the source and drain is 550 nanometers; complete the high-efficiency heat dissipation nitrogen based on the diamond passivation structure GaN transistor fabrication.

The present invention has been verified by repeated tests, and a satisfactory trial effect has been obtained. The gallium nitride-based device of the diamond passivation structure of the present invention has the advantages of efficient heat dissipation capability, and can be used for ultra-high power microwave power devices.

Claims (8)

1. a high-efficiency heat dissipation gallium nitride transistor based on diamond passivation structure, is characterized in that, this structural design comprises diamond passivation layer, gate-source-drain function layer, barrier layer, buffer layer and substrate successively from top to bottom ; The diamond passivation layer is a multi-layer structure, including a barrier protection layer, a seed layer and a heat conduction layer. 2. The high-efficiency heat-dissipating gallium nitride transistor based on a diamond passivation structure according to claim 1, wherein the barrier protection layer material is SiN or AlN medium with a thickness of 10-30 nanometers, and the seed layer material is a thickness of 10-30 nanometers. The carbon-based dielectric is 50 nanometers, and the thermal conductive layer is a diamond dielectric with a thickness of 400-600 nanometers. 3. The high-efficiency heat dissipation gallium nitride transistor based on a diamond passivation structure according to claim 2, wherein the diamond passivation layer adopts a step-by-step growth process, firstly growing a barrier protective layer medium and regrowing a seed layer material, and finally grow the thermal conductive layer material. 4 . The high-efficiency heat dissipation gallium nitride transistor based on a diamond passivation structure according to claim 2 , wherein the substrate is made of Si, sapphire or SiC material. 5 . 5 . The high-efficiency heat dissipation gallium nitride transistor based on a diamond passivation structure according to claim 2 , wherein the buffer layer is made of GaN material. 6 . 6 . The high-efficiency heat dissipation gallium nitride transistor based on a diamond passivation structure according to claim 2 , wherein the barrier layer is made of AlGaN material. 7 . 7. A method for manufacturing a high-efficiency heat-dissipating gallium nitride transistor based on a diamond passivation structure as claimed in any one of claims 1-6, characterized in that, comprising the steps of: 1) Preparation of source and drain functional regions: the growth of source and drain functional regions; 2) Diamond passivation preparation: First, the CVD process is used to grow the barrier protective layer, the thickness of the potential protective layer is 10-30 nanometers, and the material is SiN or AlN medium; secondly, the seed layer is grown, and the thickness of the seed layer is 10-50 nm. Nanometer carbon-based medium; finally, CVD technology is used to grow the diamond thermal conductive layer, the thickness of the thermal conductive layer is 400-600 nanometers, and the growth temperature is not higher than 750 °C; 3) gate area diamond etching: carry out the etching of the diamond passivation layer to realize the preparation of the gate area of the gallium nitride functional layer; 4) Gate metal growth: The gate metal is grown by the gate process to prepare the gate metal of the gallium nitride functional layer. The thickness of the gate metal is 50-100 nanometers larger than that of the diamond passivation layer; 5) Diamond etching in the source and drain regions: etching the diamond passivation layer to realize the preparation of the source-drain thickening interconnection region of the gallium nitride functional layer; 6) Interconnection preparation of source and drain functional regions: The thickening interconnection of source and drain functional regions is carried out by using gold evaporation growth process, and the total thickness of source and drain diamond passivation layer is 50-100 nanometers thick; Thermal GaN transistor fabrication. 8. the manufacture method of the high-efficiency heat dissipation gallium nitride transistor based on the diamond passivation structure according to claim 7, is characterized in that, in step 3) and step 5), adopt photolithography and ICP process to carry out the etching of diamond passivation layer .

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