CN206422088U - The LED of growth on a glass substrate - Google Patents

Abstract

The utility model discloses an LED epitaxial wafer grown on a glass substrate, comprising an aluminum metal layer grown on the glass substrate, a silver metal layer grown on the aluminum metal layer, an AlN buffer layer grown on the silver metal layer, GaN buffer layer grown on AlN buffer layer, undoped GaN layer grown on GaN buffer layer, n-type doped GaN thin film grown on undoped GaN layer, n-type doped GaN thin film grown on n-type doped GaN thin film InGaN/GaN multiple quantum wells, p-type doped GaN films grown on InGaN/GaN multiple quantum wells. The LED epitaxial wafer grown on the glass substrate of the utility model has the advantages of low defect density, good crystal quality and excellent luminous performance.

Description

LED Epitaxial Wafers Grown on Glass Substrates

technical field

The utility model relates to an LED epitaxial sheet, in particular to an LED epitaxial sheet grown on a glass substrate.

Background technique

Light-emitting diode (LED), as a new type of solid-state lighting source and green light source, has outstanding features such as small size, low power consumption, environmental protection, long service life, high brightness, low heat and colorful, and is widely used in outdoor lighting, commercial lighting and decoration Engineering and other fields have a wide range of applications. At present, under the background of the increasingly serious problem of global warming, saving energy and reducing greenhouse gas emissions has become an important issue faced by the whole world. A low-carbon economy based on low energy consumption, low pollution, and low emissions will become an important direction of economic development. In the field of lighting, the application of LED light-emitting products is attracting the attention of the world. As a new type of green light source product, LED must be the trend of future development. However, at this stage, the application cost of LED is high, and the luminous efficiency is low. These factors will greatly limit the development of LED in the direction of high efficiency, energy saving and environmental protection.

Group III nitride GaN has extremely excellent properties in electricity, optics and acoustics, and has attracted extensive attention in recent years. GaN is a direct bandgap material with fast acoustic wave transmission, good chemical and thermal stability, high thermal conductivity, low thermal expansion coefficient, and high breakdown dielectric strength. It is an ideal material for manufacturing high-efficiency LED devices. At present, the luminous efficiency of GaN-based LEDs has reached 28% and is still increasing, which is much higher than that of incandescent lamps (about 2%) or fluorescent lamps (about 10%) and other lighting methods commonly used today. Luminous efficiency.

If LEDs are to be widely used on a large scale, it is necessary to further improve the luminous efficiency of LED chips and reduce the price of LED chips at the same time. Although the luminous efficiency of LED has surpassed that of fluorescent lamps and incandescent lamps, the luminous efficiency of commercial LEDs is still lower than that of sodium lamps (150lm/W), and the price per lumen/watt is relatively high. At present, most GaN-based LEDs are epitaxially grown on sapphire and SiC substrates. Large-sized sapphire and SiC substrates are expensive, resulting in high LED manufacturing costs. Therefore, it is urgent to find a low-cost substrate material for epitaxial growth of GaN-based LED epitaxial wafers.

Utility model content

In order to overcome the above shortcomings and deficiencies of the prior art, the purpose of this utility model is to provide an LED epitaxial wafer grown on a glass substrate, which has the advantages of low defect density, good crystal quality and excellent luminous performance.

The purpose of this utility model is achieved through the following technical solutions:

LED epitaxial wafer grown on glass substrate, including aluminum metal layer grown on glass substrate, silver metal layer grown on aluminum metal layer, AlN buffer layer grown on silver metal layer, AlN buffer layer grown on GaN buffer layer on GaN buffer layer, non-doped GaN layer grown on GaN buffer layer, n-type doped GaN thin film grown on undoped GaN layer, InGaN/GaN multiquantum grown on n-type doped GaN thin film Well, a p-type doped GaN thin film grown on InGaN/GaN multiple quantum wells.

The thickness of the aluminum metal layer is 150-200 μm.

The thickness of the silver metal layer is 100-300nm.

The thickness of the AlN buffer layer is 5-50 nm.

The thickness of the GaN buffer layer is 50-80nm.

The thickness of the non-doped GaN layer is 200-300nm.

The thickness of the n-type doped GaN thin film is 3-5 μm.

The InGaN/GaN quantum well is 7-10 periods of InGaN well layer/GaN barrier layer, wherein the thickness of the InGaN well layer is 2-3 nm; the thickness of the GaN barrier layer is 10-13 nm.

The thickness of the p-type doped GaN thin film is 300-350 nm.

The preparation method of the LED epitaxial wafer grown on the glass substrate comprises the following steps:

(1) Polishing and cleaning the surface of the glass substrate;

(2) Growth of the aluminum metal layer: in the molecular beam epitaxy system, the aluminum metal layer is deposited under the condition that the substrate temperature is 400-600°C;

(3) Growth of the silver metal layer: in the molecular beam epitaxy system, the electron beam evaporation function in the molecular beam epitaxy system is used, and the silver metal layer is deposited under the condition of the substrate temperature of 400-600 °C;

(4) Growth of AlN buffer layer: the substrate temperature is adjusted to 450-550°C, the pressure of the reaction chamber is 4.0-7.2×10 ^-5 Pa, and the growth rate is 0.2-0.8ML/s to deposit metal aluminum film , and then nitriding the metal aluminum thin film by using a nitrogen plasma ion source, the power of the plasma ion source is 300-450W, the flow rate of nitrogen gas is 1-5 sccm, and the nitriding time is 10-50 minutes to obtain an AlN thin film;

(5) GaN buffer layer epitaxial growth: the substrate temperature is adjusted to 450-550°C, the pressure in the reaction chamber is 6.0-7.2×10 ^-5 Pa, the beam current ratio V/III is 50-60, and the growth rate is 0.4 Growth of GaN buffer layer under the condition of ~0.6ML/s;

(6) Epitaxial growth of non-doped GaN layer: the molecular beam epitaxy growth process is adopted, the substrate temperature is 500-600°C, the pressure in the reaction chamber is 4.0-5.0×10 ^-5 Pa, and the beam current ratio V/III value growing non-doped GaN on the GaN buffer layer obtained in step (4) under the conditions of 30 to 40 and a growth rate of 0.6 to 0.8 ML/s;

(7) Epitaxial growth of n-type doped GaN film: using molecular beam epitaxy growth process, the substrate temperature is raised to 650-750°C, the pressure in the reaction chamber is 5.0-6.0×10 ^-5 Pa, the beam current ratio V/ Under the conditions of III value of 40-50 and growth rate of 0.6-0.8ML/s, n-type doped GaN film is grown on the non-doped GaN layer;

(8) Epitaxial growth of InGaN/GaN multiple quantum wells: molecular beam epitaxy growth process is adopted, the growth temperature is 750-850°C, the pressure in the reaction chamber is 4.0-5.0×10 ^-5 Pa, and the beam current ratio V/III value InGaN/GaN multiple quantum wells are grown on n-type doped GaN films under the conditions of 30-40 and growth rate of 0.4-0.6ML/s;

(9) Epitaxial growth of p-type doped GaN film: use molecular beam epitaxy growth process, adjust the substrate temperature to 650-750°C, the pressure of the reaction chamber is 5.0-6.0×10 ^-5 Pa, and the beam current ratio is V/III The p-type doped GaN thin film is grown on the InGaN/GaN multi-quantum well under the condition of the value of 30-40 and the growth rate of 0.6-0.8ML/s.

Compared with the prior art, the utility model has the following advantages and beneficial effects:

(1) The LED epitaxial wafer grown on the glass substrate of the utility model can effectively reduce the formation of dislocations, prepare high-quality LED epitaxial wafers, and improve the radiation recombination efficiency of carriers, which can greatly improve Luminous efficiency of LEDs.

(2) For the LED epitaxial wafer grown on the glass substrate of the present invention, after the glass substrate is removed, the aluminum metal layer has the functions of being a support layer, conducting electricity and heat conduction; the silver metal layer has the function of light emission. The growth of GaN film on the pre-deposited aluminum and silver metal layers lays the foundation for the preparation of low-cost, high thermal conductivity, high electrical conductivity, and high luminous performance LEDs.

(3) The utility model uses glass as a substrate, and the glass substrate is easy to obtain and cheap, which is conducive to reducing production costs.

(4) The utility model adopts a glass substrate, which has the advantage of being easy to remove, and then makes an n-type electrode on the LED epitaxial wafer after removing the glass substrate, which can be beneficial to the preparation of a vertically structured LED.

Description of drawings

FIG. 1 is a schematic cross-sectional view of the LED epitaxial wafer prepared in Example 1.

FIG. 2 is an electroluminescence (EL) spectrum of the LED epitaxial wafer prepared in Example 1. FIG.

detailed description

The utility model will be described in further detail below in conjunction with the examples, but the implementation of the utility model is not limited thereto.

Example 1

As shown in Figure 1, the LED epitaxial wafer grown on the glass substrate prepared in this embodiment includes an aluminum metal layer 11 grown on a glass substrate 10, a silver metal layer 12 grown on the aluminum metal layer 11, and a growth The AlN buffer layer 13 on the silver metal layer 12, the GaN buffer layer 14 grown on the AlN buffer layer 13, the undoped GaN layer 15 grown on the GaN buffer layer 14, the undoped GaN layer 15 grown on the undoped GaN layer 15 An n-type doped GaN thin film 16, an InGaN/GaN quantum well 17 grown on the n-type doped GaN thin film 16, and a p-type doped GaN thin film 18 grown on the InGaN/GaN quantum well 17.

The preparation method of the LED epitaxial wafer grown on the glass substrate of the present embodiment comprises the following steps:

(1) Selection of substrate: use ordinary glass substrate;

(2) Substrate surface polishing and cleaning treatment;

The surface polishing of the substrate is specifically:

First, the surface of the glass substrate is polished with diamond slurry, and the surface of the substrate is observed with an optical microscope until there are no scratches, and then the chemical mechanical polishing method is used for polishing;

The cleaning is specifically:

Put the glass substrate into deionized water and ultrasonically clean it at room temperature for 3 minutes to remove the dirt particles on the surface of the glass substrate, then wash it with acetone and ethanol in order to remove the surface organic matter, and dry it with high-purity dry nitrogen;

(3) Growth of the aluminum metal layer: in the molecular beam epitaxy system, the aluminum metal layer with a thickness of 150 μm is deposited under the condition of the substrate temperature of 400 ° C;

(4) Growth of the silver metal layer: in the molecular beam epitaxy system, the electron beam evaporation function in the molecular beam epitaxy system is used, and the silver metal layer with a thickness of 100nm is deposited under the condition that the substrate temperature is 400°C;

(5) Growth of AlN buffer layer: adjust the substrate temperature to 500°C, deposit a metal aluminum film with a thickness of 10nm under the conditions of a reaction chamber pressure of 4.0×10 ^-5 Pa and a growth rate of 0.2ML/s, and then The aluminum layer was nitrided by a nitrogen plasma source, the power of the nitrogen plasma source was 300 W, the flow rate of nitrogen gas was 1.5 sccm, and the nitriding time was 10 minutes to obtain an AlN film.

(6) GaN buffer layer epitaxial growth: the substrate temperature is adjusted to 500°C, the pressure of the reaction chamber is 6.0×10 ^-5 Pa, the beam current ratio V/III is 50, and the growth rate is 0.4ML/s. Grow a GaN buffer layer with a thickness of 50nm;

(7) Epitaxial growth of non-doped GaN layer: using molecular beam epitaxy growth process, the substrate temperature is 500°C, the pressure in the reaction chamber is 4.0×10 ^-5 Pa, the beam current ratio V/III is 30, and the growth Under the condition of a speed of 0.6ML/s, a non-doped GaN thin film with a thickness of 200nm is grown on the GaN buffer layer obtained in step (4).

(8) Epitaxial growth of n-type doped GaN film: using molecular beam epitaxy growth process, the substrate temperature is 650°C, the pressure in the reaction chamber is 5.0×10 ^-5 Pa, the beam current ratio V/III is 40, and the growth Under the condition of a speed of 0.6ML/s, grow an n-type doped GaN film with a thickness of 3 μm on the non-doped GaN layer obtained in step (5);

(9) Epitaxial growth of InGaN/GaN multiple quantum wells: using molecular beam epitaxy growth process, the growth temperature is 750°C, the pressure in the reaction chamber is 4.0×10 ^-5 Pa, the beam current ratio V/III is 30, the growth Under the condition of a speed of 0.4ML/s, grow InGaN/GaN multiple quantum wells on the n-type doped GaN film obtained in step (6); the InGaN/GaN quantum wells are 7 cycles of InGaN well layers/GaN barrier layers , wherein the thickness of the InGaN well layer is 2nm, and the thickness of the GaN barrier layer is 10nm;

(10) Epitaxial growth of p-type doped GaN film: using molecular beam epitaxy growth process, the substrate temperature is 650°C, the pressure in the reaction chamber is 5.0×10 ^-5 Pa, the beam current ratio V/III is 30, Under the condition of a growth rate of 0.6ML/s, a p-type doped GaN film with a thickness of 300nm grown on the InGaN/GaN multi-quantum well obtained in step (7) was measured, and the p-type doped GaN film prepared in this embodiment The roughness RMS value of the film is lower than 1.6nm; indicating that a smooth high-quality p-type doped GaN film is obtained.

Fig. 2 is the EL spectrum of the LED epitaxial wafer prepared by the utility model, and its electroluminescence peak is 455.6nm, and the half-maximum width is 22.2nm, reaches the current lighting requirement level, has shown the excellent performance of the LED device prepared by the utility model electrical properties.

Example 2

The preparation method of the LED epitaxial wafer grown on the glass substrate of the present embodiment comprises the following steps:

(1) Selection of substrate: use ordinary glass substrate;

(2) Substrate surface polishing and cleaning treatment;

The surface polishing of the substrate is specifically:

First, the surface of the glass substrate is polished with diamond slurry, and the surface of the substrate is observed with an optical microscope until there are no scratches, and then the chemical mechanical polishing method is used for polishing;

The cleaning is specifically:

Put the glass substrate into deionized water and ultrasonically clean it at room temperature for 5 minutes to remove the dirt particles on the surface of the glass substrate, then wash it with acetone and ethanol in sequence to remove the surface organic matter, and dry it with high-purity dry nitrogen;

(3) Growth of the aluminum metal layer: in the molecular beam epitaxy system, the aluminum metal layer with a thickness of 200 μm is deposited under the condition of the substrate temperature of 600 ° C;

(4) Growth of the silver metal layer: in the molecular beam epitaxy system, the electron beam evaporation function in the molecular beam epitaxy system is used, and the silver metal layer with a thickness of 300nm is deposited under the condition that the substrate temperature is 600°C;

(5) Growth of AlN buffer layer: the substrate temperature is 550°C, the pressure of the reaction chamber is 7.2×10 ^-5 Pa, and the growth rate is 0.2ML/s. A metal aluminum film with a thickness of 20nm is deposited, and then A nitrogen plasma source was used to nitride the aluminum layer. The power of the nitrogen plasma source was 300 W, the flow rate of nitrogen gas was 1.5 sccm, and the nitriding time was 20 minutes to obtain an AlN film.

(6) Epitaxial growth of GaN buffer layer: the substrate temperature is 550°C, the pressure of the reaction chamber is 6.0×10 ^-5 Pa, the beam current ratio V/III is 50, and the growth rate is 0.4ML/s. A GaN buffer layer with a thickness of 50nm;

(7) Epitaxial growth of non-doped GaN layer: using molecular beam epitaxy growth process, the substrate temperature is 600°C, the pressure in the reaction chamber is 4.0×10 ^-5 Pa, the beam current ratio V/III is 30, and the growth Under the condition of a speed of 0.6ML/s, a non-doped GaN thin film with a thickness of 200nm is grown on the GaN buffer layer obtained in step (4).

(8) Epitaxial growth of n-type doped GaN film: using molecular beam epitaxy growth process, the substrate temperature is 750°C, the pressure in the reaction chamber is 5.0×10 ^-5 Pa, the beam current ratio V/III is 40, and the growth Under the condition of a speed of 0.6ML/s, grow an n-type doped GaN film with a thickness of 3 μm on the non-doped GaN layer obtained in step (5);

(9) Epitaxial growth of InGaN/GaN multiple quantum wells: the molecular beam epitaxy growth process is adopted, the substrate temperature is 850°C, the pressure in the reaction chamber is 4.0×10 ^-5 Pa, and the beam current ratio V/III is 30, Under the condition that the growth rate is 0.4ML/s, grow InGaN/GaN multiple quantum wells on the n-type doped GaN film obtained in step (6); the InGaN/GaN quantum wells are 7 cycles of InGaN well layers/GaN barriers layer, wherein the thickness of the InGaN well layer is 2nm, and the thickness of the GaN barrier layer is 10nm;

(10) Epitaxial growth of p-type doped GaN film: molecular beam epitaxy growth process is adopted, the substrate temperature is 750°C, the pressure in the reaction chamber is 5.0×10 ^-5 Pa, and the beam current ratio V/III is 30, A p-type doped GaN thin film with a thickness of 300 nm is grown on the InGaN/GaN multiple quantum well obtained in step (7) under the condition of a growth rate of 0.6ML/s.

The LED epitaxial wafer on the glass substrate prepared in this embodiment has very good performance in terms of electrical properties, optical properties, defect density, and crystal quality. The test data is similar to that of Example 1, and will not be repeated here. .

The above-mentioned embodiment is a preferred implementation mode of the present utility model, but the implementation mode of the present utility model is not limited by the described embodiment, and any other changes, modifications, modifications, Substitution, combination, and simplification should all be equivalent replacement methods, and are all included in the protection scope of the present utility model.

Claims (9)

1. The LED epitaxial wafer grown on the glass substrate is characterized in that, comprising the aluminum metal layer grown on the glass substrate, the silver metal layer grown on the aluminum metal layer, the AlN buffer layer grown on the silver metal layer , a GaN buffer layer grown on an AlN buffer layer, an undoped GaN layer grown on a GaN buffer layer, an n-type doped GaN film grown on an undoped GaN layer, an n-type doped GaN film grown on InGaN/GaN multiple quantum wells, p-type doped GaN films grown on InGaN/GaN multiple quantum wells. 2 . The LED epitaxial wafer grown on a glass substrate according to claim 1 , wherein the thickness of the aluminum metal layer is 150-200 μm. 3 . The LED epitaxial wafer grown on a glass substrate according to claim 1 , wherein the silver metal layer has a thickness of 100-300 nm. 4 . 4 . The LED epitaxial wafer grown on a glass substrate according to claim 1 , wherein the thickness of the AlN buffer layer is 5-50 nm. 5 . The LED epitaxial wafer grown on a glass substrate according to claim 1 , wherein the thickness of the GaN buffer layer is 50-80 nm. 6 . The LED epitaxial wafer grown on a glass substrate according to claim 1 , wherein the thickness of the non-doped GaN layer is 200-300 nm. 7 . The LED epitaxial wafer grown on a glass substrate according to claim 1 , wherein the n-type doped GaN thin film has a thickness of 3-5 μm. 8. The LED epitaxial wafer grown on a glass substrate according to claim 1, wherein the InGaN/GaN quantum well is an InGaN well layer/GaN barrier layer with 7 to 10 cycles, wherein the InGaN well layer The thickness of the GaN barrier layer is 2-3nm; the thickness of the GaN barrier layer is 10-13nm. 9 . The LED epitaxial wafer grown on a glass substrate according to claim 1 , wherein the thickness of the p-type doped GaN thin film is 300-350 nm.