CN218039207U - HEMT and blue light LED monolithic integrated chip - Google Patents

Abstract

The utility model belongs to the technical field of semiconductor manufacturing, and discloses a HEMT and blue light LED monolithic integrated chip, which comprises a HEMT epitaxial layer and a LED epitaxial layer which are grown on a substrate; etching the structure to obtain a HEMT region and an LED region; preparing a source electrode, a drain electrode and a grid electrode in the HEMT region; preparing a transparent conducting layer, a current blocking layer, a mirror reflection layer, an N-type electrode and a P-type electrode in an LED area, and connecting the HEMT and the LED through a metal bridge; the utility model discloses a HEMT's control carries out the drive to LED, changes voltage control into by current control, and monolithic integration through sharing same material platform can greatly reduced lighting system's manufacturing cost and size, reduces parasitic effect, establishes the basis for the research of functional and the two excellent integrated chip of stability.

Description

HEMT and blue light LED monolithic integrated chip

Technical Field

The utility model relates to a semiconductor manufacturing technology field especially relates to a HEMT and blue light LED monolithic integrated chip.

Background

The GaN material has the advantages of large forbidden bandwidth, high breakdown field intensity, large heat conductivity, high electron saturation velocity and the like, the electronic device especially mainly takes a GaN/AlGaN heterojunction HEMT device as a main part, and due to spontaneous polarization and piezoelectric polarization effect, a nitride heterostructure can form high-concentration two-dimensional electron gas at an interface, and is very suitable for a high-frequency power device due to large electron mobility. The SiC substrate with good heat dissipation characteristics can be grown, and the Si substrate with low price and mature process can also be grown. Besides high-frequency devices, nitrides are also remarkably applied to photoelectric devices, the forbidden band width range covers the whole spectrum, blue LEDs are mainly used, the illumination efficiency is greatly improved, and the working time is longer compared with that of the traditional fluorescent lamp and incandescent lamp. With the recent proliferation of smart lighting applications, the need for monolithic integration of Light Emitting Diodes (LEDs) with Field Effect Transistors (FETs) has increased, which typically involves external circuit design. By sharing monolithic integration of the same material platform, the manufacturing cost and size of the illumination system can be greatly reduced, providing strong functionality and stability for a wide range of applications.

The current methods for monolithic integration of GaNHEMT-LED mainly include two methods: 1. non-metal contact, alGaN/GaNHEMT structures are grown on sapphire substrates by MOCVD, and after LED growth and characterization, siO is deposited by PECVD ₂ And a layer patterned by photolithography and BOE etching of the buffer oxide for selectively growing the HEMT structure. The 2DEG of the HEMT is laterally connected to the N-type GaN electrode of the LED by intimate contact of the epitaxial layers without the need for external metal interconnects. 2. And (3) metal contact, wherein the LED directly grows on the surface of the HEMT during epitaxial growth, etching is subsequently performed to expose the HEMT, and the HEMT drain electrode is connected with the LEDN type electrode through a metal bridge. The method can reduce the consumption and defect formation caused by secondary epitaxy.

However, when the HEMT epitaxial structure is grown at a higher temperature than the LED and secondary epitaxy is performed, defects generated at a high temperature may lower the light emission efficiency of the quantum well. And the secondary epitaxy is performed on the basis of LED epitaxial structure etching, and damage generated by etching has a large influence on the growth quality of the HEMT interface, so that the on-resistance is increased. Therefore, development of an integrated chip with simple preparation process and excellent conductivity is urgently needed in the field.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a HEMT and blue light LED monolithic integrated chip has solved the defect that secondary epitaxy that current monolithic integrated chip's synthetic method exists produced under the high temperature can reduce the luminous efficacy of quantum well, and the damage that the sculpture produced has great influence to HEMT interface department growth quality, arouses on-resistance grow scheduling problem.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides a HEMT and blue light LED monolithic integrated chip, integrated chip includes that HEMT is regional and LED is regional, HEMT is regional from bottom to top including DBR reflection stratum, substrate, alN buffer layer, gaN channel layer, alGaN barrier layer, gaN cap layer, siO ₂ A passivation layer and an HEMT electrode layer; the HEMT electrode layer comprises a source electrode, a drain electrode and a gate electrode; the LED region comprises a DBR reflecting layer, a substrate, an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer, a GaN cap layer, an N-GaN layer, an InGaN/GaN multi-quantum well layer, a P-GaN layer, a current blocking layer, a transparent conducting layer, a passivation layer, an N electrode and a P electrode from bottom to top; and the drain electrode of the HEMT area is connected with the N electrode of the LED area through the metal bridge so as to realize the electrical conduction between the HEMT area and the LED area.

Preferably, the substrate is independently a sapphire substrate; the AlN buffer layer is in contact with the substrate, and the AlN buffer layer has a thickness of 14 to 16nm.

Preferably, the GaN channel layer is independently an unintentionally doped GaN layer and has a thickness of 200 to 300nm.

Preferably, the AlGaN barrier layer has an Al doping concentration of 0.2 to 0.3wt%, the AlGaN barrier layer has a thickness of 20 to 30nm, and the GaN cap layer has a thickness of 2nm.

Preferably, the N-GaN layer is a Si-doped GaN layer having a thickness of 1.5 to 2.5 μm and a Si doping concentration of 2.2X 10 ¹⁹ wt%; the InGaN/GaN multi-quantum well layer is an InGaN/GaN layer which is overlapped periodically, and the thickness of the InGaN/GaN multi-quantum well layer is 130-140 nm.

Preferably, the P-GaN layer is a Mg-doped GaN layer with a thickness of 580-620nm and a Mg doping concentration of 1.5 × 10 ¹⁹ wt％。

Preferably, the source electrode, the drain electrode, the N electrode, and the P electrode are independently in ohmic contact, and the source electrode, the drain electrode, the N electrode, and the P electrode are each an alloy of at least two metals selected from Cr, al, ti, pt, and Au.

Preferably, the metal bridge is an alloy consisting of at least two metals of Cr, al, ti, pt and Au; the gate electrode is in Schottky contact and is an alloy of Ni and Au.

Preferably, the area ratio of the HEMT region to the LED region is 1 to 3:1 to 2.

Known through foretell technical scheme, compare with prior art, the utility model discloses beneficial effect as follows:

the utility model discloses a disposable epitaxy has reduced the production of consumption and defect, plates the DBR reflector behind the attenuate substrate, has improved the light output of device. Meanwhile, the contact area of the metal electrode is increased, the heat dissipation effect is increased, and the luminous efficiency and the reliability are effectively improved. The existence of the metal bridge enables the LED to be controlled by the HEMT, voltage drive is formed, and the integrated system is miniaturized. Compared with secondary metal evaporation, the system has the advantages that the light output power is improved by 5% and the output power is reduced by 3% under the condition that the test current is unchanged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a structural diagram of a HEMT and blue LED monolithic integrated chip obtained in embodiment 1 of the present invention, wherein 0 — sapphire substrate; 1-DBR reflective layer; 2-an AlN buffer layer; 3-a GaN channel layer; 4-AlGaN barrier layer; 5-a GaN cap layer; 6-N-GaN layer; 7-InGaN/GaN multi-quantum well layer; 8-P-GaN layer; 9-a transparent conductive layer; 10-a current blocking layer; 11-a P electrode; 12-drain electrode/N-pole (metal bridge); 13-electrode bridge; 14-a gate electrode; 15-a passivation layer; 16-a source electrode;

fig. 2 is a top view structure diagram of the HEMT and blue light LED monolithic integrated chip obtained in embodiment 1 of the present invention;

fig. 3 is a structural diagram of the HEMT and blue LED monolithic integrated chip epitaxy obtained in embodiment 1 of the present invention;

fig. 4 is a structural diagram of the source electrode, the drain electrode, the gate electrode, the N electrode, the P electrode, and the metal bridge in the structure of the HEMT and blue LED monolithic integrated chip according to embodiment 1 of the present invention.

Detailed Description

The utility model provides a HEMT and blue light LED monolithic integrated chip, integrated chip includes that HEMT is regional and LED is regional, HEMT is regional from bottom to top including DBR reflection stratum, substrate, alN buffer layer, gaN channel layer, alGaN barrier layer, gaN cap layer, siO ₂ A passivation layer and an HEMT electrode layer; the HEMT electrode layer comprises a source electrode, a drain electrode and a gate electrode; the LED region comprises a DBR reflecting layer, a substrate, an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer, a GaN cap layer, an N-GaN layer, an InGaN/GaN multi-quantum well layer, a P-GaN layer, a current blocking layer, a transparent conducting layer, a passivation layer, an N electrode and a P electrode from bottom to top; and the drain electrode of the HEMT area is connected with the N electrode of the LED area through the metal bridge so as to realize the electrical conduction between the HEMT area and the LED area.

In the present invention, the substrate is independently a sapphire substrate; the AlN buffer layer is in contact with the substrate, and the AlN buffer layer has a thickness of preferably 14 to 16nm, more preferably 15nm, independently.

In the present invention, the GaN channel layer is independently an unintentionally doped GaN layer, and the thickness thereof is independently preferably 200 to 300nm, and more preferably 230 to 280nm.

In the present invention, the Al doping concentration of the AlGaN barrier layer is preferably 0.2 to 0.3wt%, and more preferably 0.22 to 0.28wt%; the AlGaN barrier layer is independently preferably 20 to 30nm, more preferably 25nm in thickness; the thickness of the GaN cap layer is independently 2nm.

In the present invention, the N-GaN layer is a Si-doped GaN layer, and the thickness is preferably 1.5 to 2.5 μm, and more preferably 1.8 to 2 μm; the doping concentration of Si is 2.2X 10 ¹⁹ wt%; the InGaN/GaN multi-quantum well layer is a periodically overlapped InGaN/GaN layer, and the thickness of the InGaN/GaN multi-quantum well layer is preferably 130-140 nm, and more preferably 132-138 nm.

In the present invention, the P-GaN layer is a Mg-doped GaN layer, and the thickness is preferably 580 to 620nm, and more preferably 600 to 610nm; mg doping concentration of 1.5X 10 ¹⁹ wt％。

In the present invention, the source electrode, the drain electrode, the N electrode, and the P electrode are independently ohmic contacts, and the source electrode, the drain electrode, the N electrode, and the P electrode are preferably alloys composed of at least two metals of Cr, al, ti, pt, and Au, and are more preferably alloys composed of at least two metals of Cr, ti, and Au.

In the present invention, the metal bridge is preferably an alloy composed of at least two metals of Cr, al, ti, pt, and Au, and is more preferably an alloy composed of at least two metals of Cr, ti, and Pt; the gate electrode is in Schottky contact and is an alloy of Ni and Au.

The utility model discloses in, the area ratio of HEMT region and LED region is preferably 1 ~ 3:1 to 2, more preferably 1 to 2.

The utility model also provides a HEMT and blue light LED monolithic integrated chip preparation method, including following step:

s1: providing a sapphire substrate, and growing an HEMT epitaxial layer and an LED epitaxial layer on the substrate to form an HEMT-LED structure; the HEMT structure consists of a sapphire substrate, an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer and a GaN cap layer from bottom to top; the LED structure consists of an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer, a GaN cap layer, an N-GaN layer, an InGaN/GaN multi-quantum well layer and a P-GaN layer from bottom to top;

s2: cleaning, photoetching and ICP (inductively coupled plasma) etching are carried out on the HEMT-LED epitaxial structure to obtain an HEMT region and an LED region;

s3: deposition of SiO on LED regions by PECVD ₂ Forming a current blocking layer and a metal bridge step;

s4: performing ITO evaporation and annealing treatment on the LED area in sequence;

s5: cleaning, photoetching and ICP etching are carried out on the HEMT area, and a source electrode, a drain electrode/N electrode and a P electrode are prepared in the HEMT area and the LED area;

s6: preparation of a gate electrode on a HEMT region followed by deposition of SiO by PECVD ₂ Passivating to form a passivation layer to obtain the HEMT-LED epitaxial wafer;

s7: thinning the substrate of the HEMT-LED epitaxial wafer;

s8: and evaporating a DBR reflecting layer on the back surface to obtain the HEMT and blue light LED monolithic integrated chip.

In the present invention, in step S2, the ICP etching is performed to remove the P-GaN layer, the quantum well layer, and the N-GaN layer, which are 2230nm thick, until the GaN cap layer is exposed to allow the integrated device to be divided into the HEMT region and the LED region, and then the HEMT region and the LED region are cleaned with the cleaning solution;

the cleaning liquid is prepared from concentrated sulfuric acid, water and hydrogen peroxide according to the proportion of 5.

In the utility model, siO is deposited on the LED region by PECVD ₂ Firstly, etching a part of the P-GaN layer and the quantum well layer of the LED region at 1000nm by photoetching and ICP etching until the N-GaN layer is exposed; and further etching the region between the HEMT region and the LED region to 340nm and 10 μm in width.

In the present invention, in the step S3, the adhesion promoter is used on the LED region, and the PECVD technique is used to deposit SiO on the P-GaN left in the step S2 ₂ And the current blocking layer increases the recombination efficiency of the holes and the electrons, and the thickness of the current blocking layer is 200nm.

In the present invention, in step S3, the wet etching is performed on the current blocking layer by using the etching solution through the photolithography and the development, and the etching solution is HF and NH having a mass ratio of 1:6-10 ₄ And F, a mixed solution.

In the utility model, theIn step S4, the ITO evaporation comprises the specific steps of: ITO (1100A) deposition by electron beam evaporation technique to deposit In ₂ O ₃ And (3) plating an oxide on the surface to form a current diffusion layer, and then carrying out photoetching and developing, wherein the mass ratio of the current diffusion layer to the oxide is 1.6:1 HCl and FeCl ₃ The mixed solution of (2) and (3) adding excess In ₂ O ₃ Removing the oxide; the annealing treatment comprises the following specific steps: the inlet flow rate ratio is 9 multiplied by 10 ⁴ :2.5 of N ₂ And O ₂ And further oxidizing the suboxide at high temperature to improve the conductivity and light transmittance of the ITO film.

The utility model discloses in, in step S5, wash, photoetching, ICP sculpture to HEMT region, regional source electrode, drain electrode/N electrode, the specific step of P electrode of preparation in HEMT region and LED region is: etching off the GaN cap layer and the AlGaN barrier layer in the HEMT region through photoetching and ICP etching to expose a GaN channel layer, wherein the etching depth is 27nm; bonding SiO by PECVD technique using adhesion promoter ₂ Depositing the etching area between the HEMT and the LED to form a step for the connection of the metal bridge; forming an electrode by photoetching and developing, depositing one or more of Cr, al, ti, pt and Au by using an electron beam evaporation technology, annealing at 265 ℃ for 5min to form a source electrode, a drain/N (metal bridge) electrode and a P electrode of the chip, and then tearing gold from a blue film; and depositing Ni and Au by photoetching and developing by using an electron beam evaporation technology to form a gate electrode, and then carrying out blue film stripping.

In the present invention, in step S6, wet etching is performed on the passivation layer by using an etching solution to expose five electrodes, so as to obtain an HEMT-LED epitaxial wafer; the etching liquid is independently composed of 1: 6-1: 10 HF and NH ₄ F, and preparing a mixed solution.

In the present invention, in step S7, the thinning of the substrate of the HEMT-LED epitaxial wafer is performed by grinding, and the thickness of the substrate of the HEMT-LED epitaxial wafer after thinning is 150 μm.

The utility model discloses in, in step S8, the concrete step of coating by vaporization is: mixing SiO ₂ And TiO ₂ Alternately arranged to form a periodic structure, increasing light reflection, and having a vapor deposition layer number of 49 layers.

The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of the present invention.

Example 1

The embodiment provides a monolithic integrated chip of an HEMT and a blue light LED, which comprises an HEMT region and an LED region, wherein the HEMT region sequentially comprises a DBR reflecting layer, a substrate, an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer, a GaN cap layer, a passivation layer and an HEMT electrode layer from bottom to top; the LED region comprises a DBR reflecting layer, a substrate, an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer, a GaN cap layer, an N-GaN layer, an InGaN/GaN multi-quantum well layer, a P-GaN layer, a current blocking layer, a transparent conducting layer, a passivation layer, an N electrode and a P electrode from bottom to top, and a drain electrode of the HEMT region is connected with the P electrode of the LED through a metal bridge so as to realize the electrical conduction between the HEMT region and the LED region.

The preparation of the HEMT and blue light LED monolithic integrated chip comprises the following steps:

(1) Sequentially epitaxially growing a full structure on a sapphire substrate by using an MOCVD (metal organic chemical vapor deposition) technology, wherein the full structure comprises a 15nm AlN buffer layer, a 300nm GaN channel layer and a 25nm AlGaN barrier layer; the component concentration of the AlGaN barrier layer A1 is 0.2;2nm GaN cap layer, 1.5 μm N-GaN layer, 130nm quantum well layer, 600nm P-GaN layer;

(2) Etching a P-GaN layer, a quantum well layer and an N-GaN layer which are 2230nm thick in total by photoetching and developing on the epitaxial structure in the step (1) and etching by using ICP (inductively coupled plasma) until the GaN cap layer is exposed, so that the integrated device is divided into an HEMT (high electron mobility transistor) area and an LED (light emitting diode) area; the HEMT region comprises an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer and a GaN cap layer;

(3) Cleaning the epitaxial wafer in the step (2) by using a cleaning solution (prepared by concentrated sulfuric acid, water and hydrogen peroxide according to the proportion of 5;

(4) Etching partial P-GaN layer, quantum well layer and N-GaN layer in the LED region to expose N-GaN layer by photoetching and ICP etching, wherein the total thickness is 1000nm; further etching the area between the HEMT and the LED to the etching depth of 340nm;

(5) Depositing SiO on the P-GaN left in the step (4) by using a PECVD technology by using an adhesion promoter on the epitaxial layer ₂ The current blocking layer increases the recombination efficiency of holes and electrons, and the thickness of the current blocking layer is 100nm;

(6) Carrying out wet etching on the current barrier layer by using BOE through photoetching and developing, wherein the components are as follows: 10 HF, NH ₄ F, mixing the solution;

(7) ITO (1100A) deposition by electron beam evaporation technique to deposit In ₂ O ₃ Plating oxide on the surface to form a current diffusion layer, photoetching, developing, and using HCl or FeCl ₃ The mixed solution removes the redundant oxides such as InO, inO and the like; further performing RTA annealing treatment on the current diffusion layer with the flow rate ratio of 9 × 10 ⁴ :2.5 of N ₂ And O ₂ Further oxidizing the low-valence oxide at 510 ℃ to improve the conductivity and light transmittance of the ITO film;

(8) Etching off the GaN cap layer and the AlGaN barrier layer in the HEMT region through photoetching and ICP etching to expose a GaN channel layer, wherein the etching depth is 27nm;

(9) Using adhesion promoter, siO in step (8) by PECVD technique ₂ Depositing the etching area between the HEMT and the LED to form a step for the connection of the metal bridge;

(10) Depositing Cr (adopting a current of 25A), al (adopting a current of 1 kA), ti (adopting a current of 1 kA), pt (adopting a current of 650A), ti (adopting a current of 1 kA), pt (adopting a current of 1 kA) and Au (adopting a current of 20 kA) by photoetching and developing by using an electron beam evaporation technology, and carrying out annealing treatment at the temperature of 265 ℃ for 5min to form a source electrode, a drain/N (metal bridge) electrode and a P electrode of the chip, and then carrying out blue film gold tearing;

(11) Depositing Ni (adopting current of 1 kA) and Au (adopting current of 2 kA) by photoetching and developing by using an electron beam evaporation technology to form a gate electrode, and then carrying out blue film gold tearing;

(12) Forming a SiO2 passivation layer (100 nm) on the surface by PECVD techniquePhotoetching and developing, and carrying out wet etching on the passivation layer by using etching liquid, wherein the etching liquid comprises the following components in percentage by mass: HF, NH of 6 ₄ F, mixing the solution;

(13) Etching the SiO in the step (11) by photoetching and developing ₂ And performing wet etching to expose five electrodes, wherein the etching solution comprises the following components in percentage by mass of 1: HF, NH of 8 ₄ F, mixing the solution;

(14) Grinding the substrate and thinning the substrate until the thickness of the substrate is 150 mu m;

(15) Performing DBR evaporation on the back surface, and evaporating SiO ₂ And TiO 2 ₂ Alternately arranging to form a periodic structure, increasing the reflection of light, and obtaining a HEMT and blue light LED monolithic integrated chip with 49 layers;

example 2

The embodiment provides a HEMT and blue light LED monolithic integrated chip, which comprises an HEMT region and an LED region, wherein the HEMT region sequentially comprises a substrate, an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer, a GaN cap layer, a passivation layer and an HEMT electrode layer from bottom to top, and the HEMT electrode layer comprises a source electrode, a drain electrode and a gate electrode; the LED area comprises a substrate, an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer, a GaN cap layer, an N-GaN layer, an InGaN/GaN multi-quantum well layer, a P-GaN layer, a current blocking layer, a transparent conducting layer, a passivation layer, an N electrode and a P electrode from bottom to top. And the drain electrode of the HEMT area is connected with the P electrode of the LED through the metal bridge so as to realize the electrical conduction between the HEMT area and the LED area.

The preparation of the HEMT and blue light LED monolithic integrated chip comprises the following steps:

(1) Sequentially epitaxially growing a full structure on a sapphire substrate by using an MOCVD (metal organic chemical vapor deposition) technology, wherein the full structure comprises a 15nm AlN buffer layer, a 300nm GaN channel layer and a 25nm AlGaN barrier layer; the component concentration of the AlGaN barrier layer A1 is 0.25wt%;2nm GaN cap layer, 2 μm N-GaN layer, 140nm quantum well layer, and 600nm P-GaN layer.

(2) Etching a P-GaN layer, a quantum well layer and an N-GaN layer which are 2740nm thick in total on the epitaxial structure in the step (1) by photoetching and developing and using ICP (inductively coupled plasma) etching until the GaN cap layer is exposed, so that the integrated device is divided into an HEMT (high electron mobility transistor) area and an LED (light emitting diode) area; the HEMT region comprises an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer and a GaN cap layer;

(3) Cleaning the epitaxial wafer in the step by using a cleaning solution (the cleaning solution is prepared from concentrated sulfuric acid, water and hydrogen peroxide according to the mass ratio of 5;

(4) Etching partial P-GaN layer, quantum well layer and N-GaN layer in the LED region to expose N-GaN layer by photoetching and ICP etching, wherein the total thickness is 1100nm; further etching the area between the HEMT and the LED, wherein the etching depth is 340nm;

(5) Depositing SiO on the P-GaN left in the step (4) by using a PECVD technology by using an adhesion promoter on the epitaxial layer ₂ The current blocking layer increases the recombination efficiency of holes and electrons, and the thickness of the current blocking layer is 200nm;

(6) And carrying out wet etching on the current barrier layer by using etching liquid through photoetching and developing, wherein the etching liquid comprises the following components in percentage by mass: HF, NH of 6 ₄ F, mixing the solution;

(7) ITO (1100A) deposition by electron beam evaporation technique to deposit In ₂ O ₃ Plating oxide to form current diffusion layer, photoetching, developing, and using HCl and FeCl ₃ The mixed solution of (2) and (3) adding excess In ₂ O ₃ Removing the oxide; further performing RTA annealing treatment on the current diffusion layer with the flow rate ratio of 9 × 10 ⁴ :2.5 of N ₂ And O ₂ Further oxidizing the low-valence oxide at high temperature to improve the conductivity and light transmittance of the ITO film;

(8) Etching the GaN cap layer and the AlGaN barrier layer in the HEMT region through photoetching and ICP etching to expose the GaN channel layer, wherein the etching depth is 27nm;

(9) Using adhesion promoter, siO in step (8) by PECVD technique ₂ Depositing in an etching area between the HEMT and the LED to form a step for the connection of the metal bridge;

(10) Depositing Cr (adopting a current of 25A), al (adopting a current of 1 kA), ti (adopting a current of 1 kA), pt (adopting a current of 650A), ti (adopting a current of 1 kA), pt (adopting a current of 1 kA) and Au (adopting a current of 20 kA) by photoetching and developing by using an electron beam evaporation technology, and carrying out annealing treatment at the temperature of 265 ℃ for 5miN to form a source electrode, a drain/N (metal bridge) electrode and a P electrode of the chip, and then carrying out blue film gold tearing;

(11) Depositing Ni (adopting current of 1 kA) and Au (adopting current of 2 kA) electrodes by photoetching and developing by using an electron beam evaporation technology to form a gate electrode, and then carrying out blue film gold tearing;

(12) Forming SiO on the surface by PECVD technology ₂ And carrying out wet etching on the passivation layer by etching and developing with etching liquid, wherein the etching liquid comprises the following components in percentage by mass of 1: HF, NH of 6 ₄ F mixed solution

(13) And (3) carrying out wet etching on the SiO2 in the step (11) by using etching liquid through photoetching and developing to expose five electrodes, wherein the etching liquid comprises the following components in percentage by mass of 1: HF, NH of 6 ₄ F, mixing the solution;

(14) Grinding the substrate, and reducing the thickness of the substrate to 150 mu m;

(15) Performing DBR evaporation on the back surface, and evaporating SiO ₂ And TiO ₂ And (3) alternately arranging to form a periodic structure, increasing the light reflection, and obtaining the HEMT and blue light LED monolithic integrated chip with 49 layers.

Example 3

The embodiment provides a HEMT and blue light LED monolithic integrated chip, which comprises an HEMT region and an LED region, wherein the HEMT region sequentially comprises a substrate, an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer, a GaN cap layer, a passivation layer and an HEMT electrode layer from bottom to top, and the HEMT electrode layer comprises a source electrode, a drain electrode and a gate electrode; the LED area comprises a substrate, an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer, a GaN cap layer, an N-GaN layer, an InGaN/GaN multi-quantum well layer, a P-GaN layer, a current blocking layer, a transparent conducting layer, a passivation layer, an N electrode and a P electrode from bottom to top. And the drain electrode of the HEMT area is connected with the P electrode of the LED through the metal bridge so as to realize the electrical conduction between the HEMT area and the LED area.

The preparation of the HEMT and blue light LED monolithic integrated chip comprises the following steps:

(1) Sequentially epitaxially growing a full structure on a sapphire substrate by using an MOCVD (metal organic chemical vapor deposition) technology, wherein the full structure comprises a 15nm AlN buffer layer, a 300nm GaN channel layer and a 25nm AlGaN barrier layer; the component concentration of the AlGaN barrier layer A1 is 0.3;2nm GaN cap layer, 2.5um N-GaN layer, 140nm quantum well layer and 600nm P-GaN layer.

(2) Etching off a P-GaN layer, a quantum well layer and an N-GaN layer which are 3240nm thick in total by photoetching and developing on the epitaxial structure in the step (1) and etching by using ICP (inductively coupled plasma) until the GaN cap layer is exposed, so that the integrated device is divided into an HEMT (high electron mobility transistor) area and an LED (light emitting diode) area; the HEMT region comprises an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer and a GaN cap layer;

(3) Cleaning the epitaxial wafer in the step (2) by using a cleaning solution (the cleaning solution is prepared from concentrated sulfuric acid, water and hydrogen peroxide according to the mass ratio of 5;

(4) Etching partial P-GaN layer, quantum well layer and N-GaN layer in the LED region to expose the N-GaN layer by photoetching and ICP etching, wherein the total thickness is 1200nm; further etching the area between the HEMT and the LED, wherein the etching depth is 340nm;

(5) Depositing SiO on the P-GaN left in the step (4) by using a PECVD technology by using an adhesion promoter on the epitaxial layer ₂ The current blocking layer increases the recombination efficiency of holes and electrons, and the thickness of the current blocking layer is 200nm;

(6) And carrying out wet etching on the current barrier layer by using etching liquid through photoetching and developing, wherein the etching liquid comprises the following components in percentage by mass: 9 HF, NH ₄ F, mixing the solution;

(7) ITO (1300A) was deposited by electron beam evaporation to deposit In ₂ O ₃ Plating oxide to form current diffusion layer, photoetching, developing, and using HCl and FeCl ₃ The mixed solution of (2) and (3) adding excess In ₂ O ₃ Removing the oxide; further performing RTA annealing treatment on the current diffusion layer with the flow rate ratio of 9 × 10 ⁴ :2.5 of N ₂ And O ₂ Further oxidizing the suboxide at 510 ℃ to improve the conductivity and light transmittance of the ITO film;

(8) Etching the GaN cap layer and the AlGaN barrier layer in the HEMT region through photoetching and ICP etching to expose the GaN channel layer, wherein the etching depth is 27nm;

(9) Using adhesion promoter, siO in step (8) by PECVD technique ₂ Depositing the etching area between the HEMT and the LED to form a step for the connection of the metal bridge;

(10) Depositing Cr (adopting a current of 25A), al (adopting a current of 1 kA), ti (adopting a current of 1 kA), pt (adopting a current of 650A), ti (adopting a current of 1 kA), pt (adopting a current of 1 kA) and Au (adopting a current of 20 kA) by photoetching and developing by using an electron beam evaporation technology, and carrying out annealing treatment at the temperature of 265 ℃ for 5miN to form a source electrode, a drain/N (metal bridge) electrode and a P electrode of the chip, and then carrying out blue film gold tearing;

(11) Depositing Ni (adopting current of 1 kA) and Au (adopting current of 2 kA) by photoetching and developing by using an electron beam evaporation technology to form a gate electrode, and then carrying out blue film gold tearing;

(12) Forming SiO on the surface by PECVD technology ₂ (100 nm) carrying out photoetching and developing on a passivation layer, and carrying out wet etching on the passivation layer by using etching liquid, wherein the etching liquid comprises the following components in percentage by mass: HF, NH of 7 ₄ F, mixing the solution;

(13) And (3) carrying out wet etching on the SiO2 in the step (11) by using etching liquid through photoetching and developing to expose five electrodes, wherein the etching liquid comprises the following components in percentage by mass of 1: HF, NH of 9 ₄ F, mixing the solution;

(14) Grinding the substrate to reduce the thickness (150 um) of the substrate;

(15) Performing DBR evaporation on the back surface, and evaporating SiO ₂ And TiO 2 ₂ And (3) alternately arranging to form a periodic structure, increasing the light reflection, and obtaining the HEMT and blue light LED monolithic integrated chip with 49 layers.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (9)

1. The HEMT and blue light LED monolithic integrated chip is characterized by comprising an HEMT region and an LED region, wherein the HEMT region comprises a DBR reflecting layer, a substrate, an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer, a GaN cap layer and SiO from bottom to top ₂ A passivation layer and an HEMT electrode layer; the HEMT electrode layer comprises a source electrode, a drain electrode and a gate electrode; the LED region comprises a DBR reflecting layer, a substrate, an AlN buffer layer, a GaN channel layer, an AlGaN barrier layer, a GaN cap layer, an N-GaN layer, an InGaN/GaN multi-quantum well layer, a P-GaN layer, a current blocking layer, a transparent conducting layer, a passivation layer, an N electrode and a P electrode from bottom to top; and the drain electrode of the HEMT area is connected with the N electrode of the LED area through the metal bridge so as to realize the electrical conduction between the HEMT area and the LED area.

2. The HEMT and blue LED monolithic integrated chip of claim 1, wherein said substrate is independently a sapphire substrate; the AlN buffer layer is in contact with the substrate, and the AlN buffer layer has a thickness of 14 to 16nm.

3. The HEMT and blue LED monolithic integrated chip of claim 2, wherein the GaN channel layer is independently an unintentionally doped GaN layer with a thickness independently of 200-300 nm.

4. The HEMT and blue LED monolithic integrated chip of claim 3, wherein the AlGaN barrier layers independently have an Al doping concentration of 0.2 to 0.3wt%, the AlGaN barrier layers independently have a thickness of 20 to 30nm, and the GaN cap layers independently have a thickness of 2nm.

5. The monolithic integrated chip of HEMT and blue LED according to any one of claims 1 to 3, wherein the N-GaN layer is a Si-doped GaN layer with a thickness of 1.5 to 2.5 μm and a Si doping concentration of 2.2 x 10 ¹⁹ wt%; the InGaN/GaN multi-quantum well layer is a InGaN/GaN layer which is overlapped periodically, and the thickness of the InGaN/GaN multi-quantum well layer is 130-140 nm.

6. The HEMT and blue LED monolithic integrated chip of claim 5, wherein the P-GaN layer is a Mg-doped GaN layer with a thickness of 580-620nm and a Mg doping concentration of 1.5 x 10 ¹⁹ wt％。

7. The monolithic integrated chip for HEMT and blue LED according to claim 6, wherein the source, drain, N and P electrodes are independently ohmic contacts, and the source, drain, N and P electrodes are an alloy of at least two metals selected from Cr, al, ti, pt and Au.

8. The monolithic integrated chip of HEMT and blue LED as claimed in claim 7, wherein the metal bridge is an alloy of at least two metals selected from Cr, al, ti, pt and Au; the gate electrode is in Schottky contact and is an alloy of Ni and Au.

9. The HEMT and blue LED monolithic integrated chip of claim 7 or 8, wherein the area ratio of the HEMT region to the LED region is 1-3: 1 to 2.

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