CN215869394U

CN215869394U - Gallium nitride HEMT device with electric field regulation between source and drain

Info

Publication number: CN215869394U
Application number: CN202123399769.XU
Authority: CN
Inventors: 刘毅; 何浩翔; 吴文杰; 唐璐; 蒋怡
Original assignee: Xinzhongxiang Chengdu Microelectronics Co ltd
Current assignee: Xinzhongxiang Chengdu Microelectronics Co ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2022-02-18
Anticipated expiration: 2031-12-31

Abstract

The utility model discloses a gallium nitride HEMT device with source-drain electric field regulation, which relates to the technical field of chip manufacturing and solves the technical problems that the manufacturing process of the traditional multilayer field plate structure is multiple and complicated, the cost is high, a medium needs to be deposited for multiple times, the thickness of each deposition is controlled, metal is deposited for multiple times, and the multilayer field plate structure is patterned by using a photoetching process for multiple times. The high-resistance circuit is utilized to realize voltage reference values between the source and the drain, different reference values are provided for field plates which are not electrically connected with each other, so that different electrode voltages and induced charges can be provided at different parts of the device according to requirements, and effective electric field regulation is provided for the high-voltage GaN HEMT device.

Description

Gallium nitride HEMT device with electric field regulation between source and drain

Technical Field

The utility model relates to the field of chip manufacturing, in particular to a gallium nitride HEMT device with a source-drain electric field regulation function.

Background

Gallium nitride is a novel compound semiconductor material, and a high-mobility transistor manufactured by taking gallium nitride as a basic material is suitable for high-frequency and high-power applications and has been successfully manufactured in the field of microwave radio frequency. Due to advances in materials technology, the technology also starts to enter the field of power electronics with higher requirements for power and reliability. The corresponding voltage-current-load grade in the field is higher, the processing power is higher, the corresponding device area is larger, and the defect density is difficult to keep lower in a consistent manner on a larger area due to the fact that the material maturity is slower to develop. In addition, the need to suppress local high electric fields is particularly low.

The applied voltage of the current industrial products of the gallium nitride power devices is about 650V, and the current is not large. Fig. 1 is a schematic diagram of a typical p-GaN HEMT power device, when a normal forward direct current high voltage is applied between a source and a drain, a gate and the source are short-circuited or a negative voltage is applied to the source, so that the device is turned off, and the normal forward direct current high voltage is applied between the source and the drain, a barrier layer and a channel layer in the whole area from a to B become depletion regions to bear an electric field, wherein the electric field intensity at a is the largest and becomes the weakest area of the device during voltage withstanding. Measures need to be taken to suppress the local peak electric field at the time of device structure design.

The most common way to suppress the local peak electric field in a semiconductor chip is the field plate structure. The mechanism is to change the local electric field distribution by utilizing the induced charges of the plate capacitor electrode. The electrode voltage of the device is conveniently utilized by the voltage of the device, and in the specific occasion of the gallium nitride HEMT device, the field plate is connected to one of a source, a drain and a grid of the device through metal, and the field plate is often called a source field plate, a drain field plate, a grid field plate and the like correspondingly.

In the device, the electric field intensity of each local part is different, and in order to make the electric field distribution uniform and not generate a peak value, local charges induced by the field plate are required to be continuously changed. But in the common field plate design, only one capacitor electrode voltage is needed, so that the thickness of the medium can be changed.

The multilayer field plate structure has the advantages of multiple and complicated manufacturing procedures, high cost, multiple times of medium deposition, control of the thickness of each deposition, multiple times of metal deposition and multiple times of patterning by using a photoetching process.

SUMMERY OF THE UTILITY MODEL

The utility model aims to: in order to solve the technical problem, the utility model provides a gallium nitride HEMT device with a regulation of an electric field between a source and a drain.

The utility model specifically adopts the following technical scheme for realizing the purpose:

a gallium nitride HEMT device with electric field regulation between a source and a drain sequentially comprises a basic epitaxial structure, a channel layer and a barrier layer from bottom to top, wherein a source region and a drain region are arranged on the upper surface of the channel layer, a gate region of p-GaN is sequentially arranged on the upper surface of the barrier layer between the source region and the drain region, a high-resistance path is arranged between the source region and the drain region, and a plurality of field plates which are separated from each other are connected on the high-resistance path.

Further, the source region is an ohmic contact.

Further, the drain region is an ohmic contact.

Further, the gate region is a schottky contact.

Furthermore, the preparation material of the high-resistance path is a high-resistance material, the high-resistance path is a step-variable path, and the thickness of the high-resistance path can be changed according to the addition and deletion of the high-resistance material.

Further, the high-resistance material comprises metal alloy and metal compound.

Furthermore, the field plate dielectric is made of silicon oxide or silicon nitride.

The utility model has the following beneficial effects:

1. according to the scheme, each voltage reference value between the source and the drain is realized by using the high-resistance circuit, different reference values are provided for each field plate which is in non-electric connection with each other, so that different electrode voltages and induced charges can be provided at different parts of the device according to requirements, and effective electric field regulation is provided for high-voltage (650V and above) GaN HEMT devices;

2. the scheme solves the problems of complicated steps of the multilayer field plate, multiple times of medium deposition, the need of controlling the thickness of each deposition and high cost. Setting the local voltage reference provides an effective electric field regulation for the field plate.

Drawings

FIG. 1 is a schematic diagram of a typical p-GaN HEMT power device of the prior art;

FIG. 2 is a schematic diagram of a gallium nitride HEMT device designed according to this invention;

fig. 3 is a schematic view of a field plate of a gallium nitride HEMT device designed in the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Examples are shown below:

as shown in fig. 1 to 3, the present embodiment provides a gallium nitride HEMT device with an electric field regulation between source and drain, which includes a basic epitaxial structure, a channel layer, and a barrier layer in sequence from bottom to top, wherein a source region and a drain region are disposed on an upper surface of the channel layer, and a gate region of p-GaN is disposed on an upper surface of the barrier layer between the source region and the drain region, wherein a high-resistance path is disposed between the source region and the drain region, and a plurality of field plates separated from each other are connected to the high-resistance path.

The working principle/working process of the utility model is as follows: after deposition of a thickness of field plate dielectric, a plurality of field plates separated from each other are formed directly by a metal deposition and photolithographic patterning process. And forming a high-resistance path between the source and the drain by depositing a high-resistance material and performing a photoetching patterning process. The current should not be significantly higher than the normal off-state source-drain leakage level to avoid significantly increasing the reverse loss. (the device reverse losses are generally very small and the ratio of conduction losses and switching losses is negligible). Different field plates are connected with different parts of the high-resistance loop to obtain different field plate electrode voltages.

Preferably, the field plate dielectric can adopt silicon dioxide or silicon nitride; the high-resistance material can adopt metal alloy or metal compound;

as shown in fig. 2, the thickness variation of the high-resistance path is the variation of the step-variable path, the thickness can be changed according to the increase and the deletion of the high-resistance material, and the voltage values at different positions are not necessarily proportional to the relative distance between the high-resistance material and the source and the drain. Can be adjusted by photolithographic patterning.

As shown in fig. 3, in order to achieve the same order of magnitude of the leakage current between the source and the drain as the previous power device, a high-resistance material such as TaN (resistivity of 128u Ω · cm, which can be effectively increased by doping AI) and Cr30Ni70 (resistivity of 1.18u Ω · m) are usually used. In order to make the resistance controllable, some semiconductor materials can be used, and polysilicon doping is used to make the resistance lower, so that the resistance is controllable.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the scope of the present invention, and any modifications, equivalents and improvements made by those skilled in the art within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The utility model provides a gallium nitride HEMT device with source leakage electric field regulation, from supreme basic epitaxial structure, channel layer and the barrier layer of including in proper order down, its characterized in that: and a source region and a drain region are arranged on the upper surface of the channel layer, and a p-GaN gate region is sequentially arranged on the upper surface of the barrier layer between the source region and the drain region, wherein a high-resistance path is arranged between the source region and the drain region, and a plurality of mutually separated field plates are connected on the high-resistance path.

2. The gallium nitride HEMT device with source-drain electric field regulation according to claim 1, wherein said source region is an ohmic contact.

3. The gallium nitride HEMT device with source-drain electric field regulation of claim 1, wherein the drain region is an ohmic contact.

4. The gallium nitride HEMT device with source-drain electric field regulation according to claim 1, wherein said gate region is a schottky contact.

5. The GaN HEMT device with the regulation of the electric field between the source and the drain according to claim 1, wherein the high resistance path is made of a high resistance material, the high resistance path is a step-change path, and the thickness of the high resistance path can be changed according to the increase and the deletion of the high resistance material.

6. The GaN HEMT device with source-drain electric field regulation as claimed in claim 5, wherein the high resistance material comprises a metal alloy or a metal compound.

7. The GaN HEMT device with source-drain electric field regulation as claimed in claim 1, wherein the field plate dielectric is made of silicon oxide or silicon nitride.