CN103208571A - GaN-based LED (light emitting diode) epitaxial wafer and production method thereof - Google Patents
GaN-based LED (light emitting diode) epitaxial wafer and production method thereof Download PDFInfo
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- CN103208571A CN103208571A CN2013101184953A CN201310118495A CN103208571A CN 103208571 A CN103208571 A CN 103208571A CN 2013101184953 A CN2013101184953 A CN 2013101184953A CN 201310118495 A CN201310118495 A CN 201310118495A CN 103208571 A CN103208571 A CN 103208571A
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Abstract
The invention provides a GaN-based LED epitaxial wafer and a production method thereof. The GaN-based LED epitaxial wafer structurally comprises a substrate, a low-temperature GaN buffer layer, an undoped GaN layer, an N-type GaN layer, a multi-quantum well layer, a multi-quantum active layer, a low-temperature P-type AlGaN layer, a high-temperature P-type GaN layer and a P-type contact layer from bottom to top. The invention also relates to a production method of the structure of the GaN-based LED epitaxial wafer. The production method includes the following steps of: purifying the substrate under a high-purity nitrogen condition; and sequentially growing the low-temperature GaN buffer layer, the undoped GaN layer, the N-type GaN layer, the multi-quantum well layer, the multi-quantum active layer, the low-temperature P-type AlGaN layer, the high-temperature P-type GaN layer and the P-type contact layer on the purified substrate. The GaN-based LED epitaxial wafer is simple in structure, the production method of the GaN-based LED epitaxial wafer is easy to achieve and obvious in effect, and the exterior surface of a product produced by the production method is of an island structure and a coarse distribution.
Description
Technical field
The invention belongs to technical field of semiconductors, particularly, relate to a kind of GaN-based LED epitaxial wafer and production method thereof.
Background technology
Light-emitting diode (LED, Light Emitting Diode) is a kind of semiconductor solid luminescence device, and it utilizes semiconductor PN as luminescent material, can directly electricity be converted to light.After the two ends of semiconductor PN add forward voltage, inject the minority carrier of PN junction and majority carrier and take place compoundly, emit superfluous energy and cause photo emissions, directly send versicolor light.
The III group-III nitride that with the gallium nitride is representative is the semiconductor material with wide forbidden band of direct band gap, has electronics drift saturated velocity height, and thermal conductivity is good, strong chemical bond, premium properties such as high temperature resistant and anticorrosive.Its ternary alloy three-partalloy indium gallium nitrogen (InGaN) band gap is adjustable continuously to 3.4eV gallium nitride (GaN) from 0.7eV indium nitride (InN), and emission wavelength has covered the whole zone of visible light and black light.
The LED luminous efficiency is to weigh one of vital index of LED device quality, and the extraction efficiency of raising LED device has become the principal element that improves luminous efficiency.When light is mapped in the process of air by the LED active area, owing to the very high reason of gallium nitride material refractive index, total reflection can take place at the interface, the cirtical angle of total reflection is very little, the light that active area produces has only minority to escape out outside the material bodies, the exitance of gallium nitride material only is 4% simultaneously, so the light extraction efficiency of LED also has very big room for promotion.
Summary of the invention
At defective of the prior art, the purpose of this invention is to provide a kind of GaN-based LED epitaxial wafer and production method thereof.
First aspect, the invention provides a kind of GaN-based LED epitaxial wafer, described epitaxial wafer is followed successively by substrate, low temperature gallium nitride resilient coating, non-doped gallium nitride layer, n type gallium nitride layer, multiple quantum well layer, the sub-active layer of volume, low temperature P type gallium nitride layer, P type gallium aluminium nitrogen layer, high temperature P type gallium nitride layer and P type contact layer from bottom to top.
Preferably, described high temperature P type gallium nitride layer is made of the first high temperature P type gallium nitride layer and the second high temperature P type gallium nitride layer.
Preferably, the thickness of the described first high temperature P type gallium nitride layer is 100～400nm, and the thickness of the described second high temperature P type gallium nitride layer is 100～400nm.
Preferably, the thickness of described low temperature gallium nitride resilient coating is that the thickness of 20～30nm, non-doped gallium nitride layer is that the thickness of 0.5～2um, n type gallium nitride layer is that the thickness of 1.2～4.2um, multiple quantum well layer is that the thickness of 2～5nm, the sub-active layer of volume is that the thickness of 2～5nm, low temperature P type gallium nitride layer is that the thickness of 10～100nm, P type gallium aluminium nitrogen layer is that the thickness of 10～50nm, high temperature P type gallium nitride layer is that the thickness of 200～800nm, P type contact layer is 5～20nm.
Second aspect the invention still further relates to a kind of production method of aforesaid GaN-based LED epitaxial wafer, and described production method comprises the steps:
Step 1, under the condition of hydrogen or nitrogen, the purified treatment substrate;
Step 2, growing low temperature gallium nitride resilient coating on the substrate after the purification;
Step 3, the non-doped gallium nitride layer of growing;
Step 4, growth n type gallium nitride layer;
Step 5, the growth multiple quantum well layer;
Step 6, the sub-active layer of growth volume;
Step 7, growing low temperature P type gallium nitride layer;
Step 8, growing P-type gallium aluminium nitrogen layer;
Step 9, growth high temperature P type gallium nitride layer;
Step 10, the growing P-type contact layer;
Preferably, in the step 1, described purified treatment is specially: 1000～1200 ℃ of clean, the time is 5-20min, and described substrate is for being fit to the material of GaN base semiconductor epitaxial material growth, as sapphire, GaN and carborundum (SiC) monocrystalline.
Preferably, in the step 2, the temperature of described growth is 500～650 ℃, and growth pressure is 300～760Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 10:1200.
Preferably, in the step 3, the temperature of described growth is 1000～1200 ℃, and growth pressure is 100～500Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 150:2000.
Preferably, in the step 4, the temperature of described growth is 1000～1200 ℃, and growth pressure is 100～600Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 100:2500.
Preferably, in the step 5, described growth temperature is 720～920 ℃, and growth pressure is between 100～600Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 200:5000, and wherein said multiple quantum well layer is the In in 2～15 cycles
xGa
1-xN/GaN (0＜x＜0.4) Multiple Quantum Well is formed, the In in 1 cycle
xGa
1-xN/GaN quantum well thickness is 2～5nm.
Preferably, in the step 6, described growth temperature is at 820～920 ℃, growth pressure is 100～500 Torr, wherein in the production process, the mol ratio of group-v element and group iii elements is 300:5000, and the molar constituent content of the In in the sub-active layer of described volume is identical with multiple quantum well layer, between 10%-50%; Barrier layer thickness is constant.
Preferably, in the step 7, described growth temperature is at 620～820 ℃, and growth time is 5～35min, and growth pressure is 100～500Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 300:4800.
Preferably, in the step 8, described growth temperature is at 900～1100 ℃, and growth time is 5～15min, and pressure is at 50～500Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 5:800, molar constituent content Russia's day 10%～30% of Al.
Preferably, in the step 9, described growth temperature is at 850～950 ℃, growth time is 3～15min, growth pressure is between 100～500Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 200:600, the flow of ammonia is 10～60 liters of every/min, and the molar flow of trimethyl gallium is 2.31 * 10
-4～5.20 * 10
-3Mole/min, the molar flow of two luxuriant magnesium is 2.7 * 10
-4～7.72 * 10
-3Mole/min.
Preferably, in the step 10, described growth temperature is at 850～1050 ℃, growth time is 1～10min, and pressure is at 100～500Torr, wherein in the production process, the mol ratio of group-v element and group iii elements is 1000:4000, and the flow of ammonia is 10～40 liters/min.
Compared with prior art, the present invention has following beneficial effect: the present invention is by adopting light face coarsening technique in the epitaxial structure growth course, the product that makes has the appearance surfaces of variation, can reduce light in the total reflection of light output surface, increase the meeting of photon escape machine, can improve escape out the probability of LED device of photon greatly, effectively improve the luminous efficiency of device.
Embodiment
The present invention is described in detail below in conjunction with specific embodiment.Following examples will help those skilled in the art further to understand the present invention, but not limit the present invention in any form.Should be pointed out that to those skilled in the art, without departing from the inventive concept of the premise, can also make some distortion and improvement.These all belong to protection scope of the present invention.
Embodiment
Present embodiment relates to a kind of GaN-based LED epitaxial wafer, and described epitaxial wafer is followed successively by substrate, low temperature gallium nitride resilient coating, non-doped gallium nitride layer, n type gallium nitride layer, multiple quantum well layer, the sub-active layer of volume, low temperature P type gallium nitride layer, P type gallium aluminium nitrogen layer, high temperature P type gallium nitride layer and P type contact layer from bottom to top.
Further, described high temperature P type gallium nitride layer is made of the first high temperature P type gallium nitride layer and the second high temperature P type gallium nitride layer.
Further, the thickness of the described first high temperature P type gallium nitride layer is 100～400nm, and the thickness of the described second high temperature P type gallium nitride layer is 100～400nm.
Further, the thickness of described low temperature gallium nitride resilient coating is that the thickness of 20～30nm, non-doped gallium nitride layer is that the thickness of 0.5～2um, n type gallium nitride layer is that the thickness of 1.2～4.2um, multiple quantum well layer is that the thickness of 2～5nm, the sub-active layer of volume is that the thickness of 2～5nm, low temperature P type gallium nitride layer is that the thickness of 10～100nm, P type gallium aluminium nitrogen layer is that the thickness of 10～50nm, high temperature P type gallium nitride layer is that the thickness of 200～800nm, P type contact layer is 5～20nm.
Present embodiment also relates to a kind of production method of aforesaid GaN-based LED epitaxial wafer, and described production method comprises the steps:
Step 1 is under the condition of hydrogen or nitrogen, 1000～1200 ℃ of clean, time is 5～20min, and then reach the purpose of purified treatment substrate, wherein substrate is elected the material that is fit to the growth of GaN base semiconductor epitaxial material as, as sapphire, GaN and carborundum (SiC) monocrystalline etc.
Step 2, on the substrate after the purification, the temperature in growth is 500～650 ℃ simultaneously, and growth pressure is 300～760Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is under the condition of 10:1200, growing low temperature gallium nitride resilient coating;
Step 3 is 500～650 ℃ in the temperature of growing, and growth pressure is 300～760Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is under the condition of 10:1200, the non-doped gallium nitride layer of growing;
Step 4 is 1000～1200 ℃ in the temperature of growing, and growth pressure is 100～600Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is under the condition of 100:2500, growth n type gallium nitride layer;
Step 5 is 720～920 ℃ in described growth temperature, and growth pressure is between 100～600Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is under the condition of 200:5000, the growth multiple quantum well layer;
Step 6, at 820～920 ℃, growth pressure is 100～500 Torr in described growth temperature, wherein in the production process, the mol ratio of group-v element and group iii elements is under the condition of 300:5000, the sub-active layer of growth volume;
Step 7, at 620～820 ℃, growth time is 5～35min in growth temperature, and growth pressure is 100～500Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is under the condition of 300:4800, growing low temperature P type gallium nitride layer;
Step 8, at 900～1100 ℃, growth time is 5～15min in growth temperature, and pressure is at 50～500Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is under the condition of 5:800, growing P-type gallium aluminium nitrogen layer;
Step 9, in growth temperature at 850～950 ℃, growth time is 3～15min, growth pressure is between 100～500Torr, wherein in the production process, the mol ratio of group-v element and group iii elements is 200:600, and the flow of ammonia is 10～60 liters/min, and the molar flow of trimethyl gallium is 2.31 * 10
-4～5.20 * 10
-3The mole per minute, the molar flow of two luxuriant magnesium is 2.7 * 10
-4～7.72 * 10
-3Under the condition of mole per minute,
Growth high temperature P type gallium nitride layer;
Step 10, at 850～1050 ℃, growth time is 1～10min in growth temperature, pressure is at 100～500Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 1000:4000, the flow of ammonia is under the condition of 10～40 liters/min, the growing P-type contact layer;
In sum, the present invention is by adopting light face coarsening technique in the epitaxial structure growth course, the product that makes has the appearance surfaces of variation, can reduce light in the total reflection of light output surface, increase the meeting of photon escape machine, can improve escape out the probability of LED device of photon greatly, effectively improve the luminous efficiency of device.
More than specific embodiments of the invention are described.It will be appreciated that the present invention is not limited to above-mentioned specific implementations, those skilled in the art can make various distortion or modification within the scope of the claims, and this does not influence flesh and blood of the present invention.
Claims (10)
1. GaN-based LED epitaxial wafer, it is characterized in that described epitaxial wafer is followed successively by substrate, low temperature gallium nitride resilient coating, non-doped gallium nitride layer, n type gallium nitride layer, multiple quantum well layer, the sub-active layer of volume, low temperature P type gallium nitride layer, P type gallium aluminium nitrogen layer, high temperature P type gallium nitride layer and P type contact layer from bottom to top.
2. GaN-based LED epitaxial wafer according to claim 1 is characterized in that, described high temperature P type gallium nitride layer is made of the first high temperature P type gallium nitride layer and the second high temperature P type gallium nitride layer.
3. GaN-based LED epitaxial wafer according to claim 1, it is characterized in that the thickness of described low temperature gallium nitride resilient coating is that the thickness of 20～30nm, non-doped gallium nitride layer is that the thickness of 0.5～2um, n type gallium nitride layer is that the thickness of 1.2～4.2um, multiple quantum well layer is that the thickness of 2～5nm, the sub-active layer of volume is that the thickness of 2～5nm, low temperature P type gallium nitride layer is that the thickness of 10～100nm, P type gallium aluminium nitrogen layer is that the thickness of 10～50nm, high temperature P type gallium nitride layer is that the thickness of 200～800nm, P type contact layer is 5～20nm.
4. the production method of a GaN-based LED epitaxial wafer as claimed in claim 1 is characterized in that, described production method comprises the steps:
Step 1, under the condition of hydrogen or nitrogen, the purified treatment substrate;
Step 2, growing low temperature gallium nitride resilient coating on the substrate after the purification;
Step 3, the non-doped gallium nitride layer of growing;
Step 4, growth n type gallium nitride layer;
Step 5, the growth multiple quantum well layer;
Step 6, the sub-active layer of growth volume;
Step 7, growing low temperature P type gallium nitride layer;
Step 8, growing P-type gallium aluminium nitrogen layer;
Step 9, growth high temperature P type gallium nitride layer;
Step 10, the growing P-type contact layer.
5. the production method of GaN-based LED epitaxial wafer according to claim 4 is characterized in that, in the step 1, described purified treatment is specially: 1000～1200 ℃ of clean, the time is 5-20min.
6. the production method of GaN-based LED epitaxial wafer according to claim 4 is characterized in that, in the step 2, the temperature of described growth is 500～650 ℃, growth pressure is 300～760Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 10:1200.
7. the production method of GaN-based LED epitaxial wafer according to claim 4 is characterized in that, in the step 3, the temperature of described growth is 1000～1200 ℃, growth pressure is 100～500Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 150:2000.
8. the production method of GaN-based LED epitaxial wafer according to claim 4 is characterized in that, in the step 4, the temperature of described growth is 1000～1200 ℃, growth pressure is 100～600Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 100:2500.
9. the production method of GaN-based LED epitaxial wafer according to claim 4 is characterized in that, in the step 5, described growth temperature is 720～920 ℃, growth pressure is between 100～600Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 200:5000.
10. the production method of GaN-based LED epitaxial wafer according to claim 4 is characterized in that, in the step 6, described growth temperature is at 820～920 ℃, growth pressure is 100～500 Torr, and wherein in the production process, the mol ratio of group-v element and group iii elements is 300:5000.
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| CN103811601A (en) * | 2014-03-12 | 2014-05-21 | 合肥彩虹蓝光科技有限公司 | Method for GaN base LED multi-stage buffer layer growth with sapphire substrate serving as substrate |
| CN105336825A (en) * | 2015-11-03 | 2016-02-17 | 湘能华磊光电股份有限公司 | LED epitaxial growth method |
| CN113421952A (en) * | 2021-06-23 | 2021-09-21 | 南方科技大学 | Micro LED chip and preparation method thereof |
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Application publication date: 20130717 |