阅读说明：本技术 一种在位生长介质层作为帽层的hemt结构及其制作方法 (HEMT structure with in-situ grown dielectric layer as cap layer and manufacturing method thereof ) 是由 王晓亮 李百泉 肖红领 于 2019-10-28 设计创作，主要内容包括：本发明公开了一种在位生长介质层作为帽层的HEMT结构,该HEMT结构从下至上依次包括：SiC衬底、成核层、缓冲层、沟道层、插入层、势垒层、盖帽层和介质层；其中,所述介质层为SiN层,其厚度不超过300μm；本发明还公开了该HEMT结构的制作方法。本发明则采用在位生长的方式制作SiN介质层,在高真空度的MOCVD腔室内,直接在HEMT结构材料的表面生长介质层,可以有效地避免因为分布沉积介质层所引入的颗粒玷污。(The invention discloses a HEMT structure with an in-situ growth dielectric layer as a cap layer, which sequentially comprises the following components from bottom to top: the device comprises a SiC substrate, a nucleating layer, a buffer layer, a channel layer, an insertion layer, a barrier layer, a cap layer and a dielectric layer; the dielectric layer is an SiN layer, and the thickness of the dielectric layer is not more than 300 mu m; the invention also discloses a manufacturing method of the HEMT structure. The SiN dielectric layer is manufactured in an in-situ growth mode, and the dielectric layer is directly grown on the surface of the HEMT structural material in the MOCVD chamber with high vacuum degree, so that particle contamination caused by distributed deposition of the dielectric layer can be effectively avoided.)

1. The HEMT structure with the in-situ grown dielectric layer as the cap layer is characterized by sequentially comprising the following components from bottom to top: the device comprises a SiC substrate, a nucleating layer, a buffer layer, a channel layer, an insertion layer, a barrier layer, a cap layer and a dielectric layer; wherein the dielectric layer is an SiN layer, and the thickness of the dielectric layer is not more than 300 mu m.

2. The HEMT structure of claim 1, wherein said nucleation layer is GaN or AlN or AlGaN with a thickness of 0.01-0.50 μm.

3. The method of claim 1The HEMT structure with in-situ grown dielectric layer as cap layer is characterized in that the buffer layer is Al_xGa_1-xN, wherein x is more than or equal to 0 and less than or equal to 0.1, and the thickness is 100nm-3000 nm.

4. The HEMT structure of claim 1, wherein said channel layer is GaN and has a thickness of 10nm-100 nm.

5. The HEMT structure of claim 1, wherein said plug-in layer is AlN and has a thickness of 1nm to 10 nm.

6. The HEMT structure with an in-situ grown dielectric layer as a cap layer according to claim 1, wherein the barrier layer is Al_xGa_1-xN, wherein x is more than or equal to 0 and less than or equal to 0.3, and the thickness is 5nm-30 nm.

7. The HEMT structure of claim 1, wherein said cap layer is GaN and has a thickness of 1nm-10 nm.

8. The HEMT structure of claim 1, wherein said SiN layer is deposited directly by MOCVD in-situ growth.

9. A method of fabricating a HEMT structure according to any one of claims 1-8 with a dielectric layer grown in-situ as a cap layer, said method comprising the steps of:

step 1: selecting a substrate, wherein the substrate is made of SiC material;

step 2: growing a nucleation layer on the substrate, wherein the nucleation layer is GaN or AlN or AlGaN and has the thickness of 0.01-0.50 mu m;

and step 3: growing a buffer layer on the nucleation layer, wherein the material is Al_xGa_1-xX is more than or equal to 0 and less than or equal to 0.20, the thickness is 100nm to 3000nm, the growth temperature is 950 ℃ to 1150 ℃, and the growth is carried outThe pressure is 5.33 kPa to 26.67 kPa;

and 4, step 4: growing a channel layer on the buffer layer, wherein the channel layer is GaN and has the thickness of 10nm-100 nm;

and 5: growing an insertion layer on the channel layer, wherein the growth thickness of the insertion layer is 1nm-10 nm;

step 6: growing a barrier layer on the insertion layer, wherein the barrier layer is made of Al_xGa_1-xN, wherein x is more than or equal to 0 and less than or equal to 0.3, and the thickness is 5nm-30 nm;

and 7: growing a cap layer on the barrier layer, wherein the cap layer is GaN and has the thickness of 1nm-10 nm;

and 8: and growing a dielectric layer on the cap layer, wherein the dielectric layer is SiN and has a thickness not more than 300 mu m.

10. The method of claim 9 wherein the steps of growing layers on the substrate include, but are not limited to, metal-organic chemical vapor deposition, molecular beam epitaxy, vapor phase epitaxy, and plasma enhanced chemical vapor deposition.

Technical Field

The invention belongs to the technical field of semiconductors, and particularly relates to a HEMT structure with an in-situ grown dielectric layer as a cap layer and a manufacturing method thereof.

Background

Gallium nitride is used as a typical representative of third-generation wide bandgap semiconductors, has excellent physical and chemical properties, is very suitable for developing high-frequency, high-voltage and high-power devices and circuits, adopts a High Electron Mobility Transistor (HEMT) developed by gallium nitride, has high current density, high power density, low noise and good frequency property, and has wide application prospect in the field of military and civil microwave power.

In the process of manufacturing GaN-based HEMT, in order to reduce the electric leakage of the device and improve the gate characteristics, SiN materials are generally adopted as passivation layers and dielectric layers under the gate, the SiN dielectric layers are mainly manufactured by adopting a PECVD or LPCVD method at present, epitaxial materials are cleaned and then placed in a PECVD or LPCVD chamber for growth, and the device is possibly polluted by particles in the cleaning process and the air exposure process, so that the performance of the device is influenced.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a HEMT structure with an in-situ growth dielectric layer as a cap layer, wherein an SiN dielectric layer is directly deposited on the surface of the traditional HEMT structure in an MOCVD in-situ growth mode. The invention also aims to provide a method for manufacturing the HEMT structure by taking the in-situ growth dielectric layer as the cap layer.

In order to achieve the purpose, the invention adopts the following technical scheme:

the HEMT structure with the in-situ grown dielectric layer as the cap layer sequentially comprises the following components from bottom to top: the device comprises a SiC substrate, a nucleating layer, a buffer layer, a channel layer, an insertion layer, a barrier layer, a cap layer and a dielectric layer; wherein the dielectric layer is an SiN layer, and the thickness of the dielectric layer is not more than 300 mu m.

Further, the nucleation layer is GaN or AlN or AlGaN and has a thickness of 0.01-0.50 μm.

Further, the buffer layer is Al_xGa_1-xN, wherein x is more than or equal to 0 and less than or equal to 0.1, and the thickness is 100nm-3000 nm.

Furthermore, the channel layer is made of GaN and has a thickness of 10nm-100 nm.

Furthermore, the insertion layer is AlN and has the thickness of 1nm-10 nm.

Further, the barrier layer is Al_xGa_1-xN, wherein x is more than or equal to 0 and less than or equal to 0.3, and the thickness is 5nm-30 nm.

Further, the cap layer is GaN and the thickness is 1nm-10 nm.

Further, the SiN layer is directly deposited by MOCVD in-situ growth.

A method for manufacturing a HEMT structure with an in-situ grown dielectric layer as a cap layer comprises the following steps:

step 1: selecting a substrate, wherein the substrate is made of SiC material;

step 2: growing a nucleation layer on the substrate, wherein the nucleation layer is GaN or AlN or AlGaN and has the thickness of 0.01-0.50 mu m;

and step 3: growing a buffer layer on the nucleation layer, wherein the material is Al_xGa_1-xN, x is more than or equal to 0 and less than or equal to 0.20, the thickness is 100nm to 3000nm, the growth temperature is 950 ℃ to 1150 ℃, and the growth pressure is 5.33 kPa to 26.67 kPa;

and 4, step 4: growing a channel layer on the buffer layer, wherein the channel layer is GaN and has the thickness of 10nm-100 nm;

and 5: growing an insertion layer on the channel layer, wherein the growth thickness of the insertion layer is 1nm-10 nm;

step 6: growing a barrier layer on the insertion layer, wherein the barrier layer is made of Al_xGa_1-xN, wherein x is more than or equal to 0 and less than or equal to 0.3, and the thickness is 5nm-30 nm;

and 7: growing a cap layer on the barrier layer, wherein the cap layer is GaN and has the thickness of 1nm-10 nm;

and 8: and growing a dielectric layer on the cap layer, wherein the dielectric layer is SiN and has a thickness not more than 300 mu m.

Further, methods for growing the layers on the substrate include, but are not limited to, metal organic chemical vapor deposition, molecular beam epitaxy, vapor phase epitaxy, and plasma enhanced chemical vapor deposition.

The invention has the following beneficial technical effects:

the SiN dielectric layer is manufactured in an in-situ growth mode, and the dielectric layer is directly grown on the surface of the HEMT structural material in the MOCVD chamber with high vacuum degree, so that particle contamination caused by distributed deposition of the dielectric layer can be effectively avoided.

Drawings

FIG. 1 is a schematic structural diagram of a HEMT structure with an in-situ grown dielectric layer as a cap layer according to the present invention;

FIG. 2 is a flow chart of a method for fabricating a HEMT structure with an in-situ grown dielectric layer as a cap layer according to the present invention.

Detailed Description

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

As shown in fig. 1, the present invention provides a HEMT structure with an in-situ grown dielectric layer as a cap layer, the HEMT structure sequentially comprises, from bottom to top: the device comprises a SiC substrate, a nucleating layer, a buffer layer, a channel layer, an insertion layer, a barrier layer, a cap layer and a dielectric layer; wherein the dielectric layer is a SiN layer with a thickness not more than 300 μm.

The nucleation layer is GaN or AlN or AlGaN, and the thickness is 0.01-0.50 μm; the buffer layer is Al_xGa_1-xN, wherein x is more than or equal to 0 and less than or equal to 0.1, and the thickness is 100nm-3000 nm; the channel layer is GaN and has a thickness of 10nm-100 nm; the insertion layer is AlN and has the thickness of 1nm-10 nm; the barrier layer is Al_xGa_1-xN, wherein x is more than or equal to 0 and less than or equal to 0.3, and the thickness is 5nm-30 nm; the cap layer is GaN with the thickness of 1nm-10 nm; the SiN layer is directly deposited by MOCVD in-situ growth.

As shown in fig. 2, the present invention provides a method for fabricating a HEMT structure with an in-situ grown dielectric layer as a cap layer, the method comprises the following steps:

step 1: selecting a substrate, wherein the substrate is made of SiC material;

step 2: growing a nucleation layer on the substrate, wherein the nucleation layer is GaN or AlN or AlGaN and has the thickness of 0.01-0.50 mu m;

and step 3: growing a buffer layer on the nucleation layer, wherein the material is Al_xGa_1-xN, x is more than or equal to 0 and less than or equal to 0.20, the thickness is 100nm to 3000nm, the growth temperature is 950 ℃ to 1150 ℃, and the growth pressure is 5.33 kPa to 26.67 kPa;

and 4, step 4: growing a channel layer on the buffer layer, wherein the channel layer is GaN and has the thickness of 10nm-100 nm;

and 5: growing an insertion layer on the channel layer, wherein the growth thickness of the insertion layer is 1nm-10 nm;

step 6: growing barrier layer on the insertion layer, wherein the barrier layer is made of Al_xGa_1-xN, wherein x is more than or equal to 0 and less than or equal to 0.3, and the thickness is 5nm-30 nm;

and 7: growing a cap layer on the barrier layer, wherein the cap layer is GaN and has the thickness of 1nm-10 nm;

and 8: and growing a dielectric layer on the cap layer, wherein the dielectric layer is SiN and has a thickness of no more than 300 mu m.

Methods for growing layers on a substrate include, but are not limited to, metal organic chemical vapor deposition, molecular beam epitaxy, vapor phase epitaxy, and plasma enhanced chemical vapor deposition; the metal organic chemical vapor deposition method is preferably used.

The above description is only for the purpose of illustrating the present invention, and it should be understood that the present invention is not limited to the above embodiments, and various modifications conforming to the spirit of the present invention are within the scope of the present invention.