CN107564999B

CN107564999B - A kind of LED epitaxial growth method of improving luminous efficiency

Info

Publication number: CN107564999B
Application number: CN201710756340.0A
Authority: CN
Inventors: 徐平
Original assignee: Xiangneng Hualei Optoelectrical Co Ltd
Current assignee: Xiangneng Hualei Optoelectrical Co Ltd
Priority date: 2017-08-29
Filing date: 2017-08-29
Publication date: 2019-05-10
Anticipated expiration: 2037-08-29
Also published as: CN107564999A

Abstract

This application discloses a kind of LED epitaxial growth methods of improving luminous efficiency, it successively include: to handle substrate, growing low temperature buffer layer GaN, grow the GaN layer that undopes, the N-type GaN layer of growth doping Si, the thin barrier layer of growth InAlN:Mg, alternating growth InxGa (1-x) N/GaN luminescent layer, the thin barrier layer InGaAlN superlattices electronic barrier layer of growth AlGaN:Mg, growing P-type AlGaN layer, the p-type GaN layer for growing doping Mg, cooling down.Through the invention, luminous efficiency decaying (efficiency droop) under Bulk current injection present in existing LED epitaxial growth is solved the problems, such as.

Description

A kind of LED epitaxial growth method of improving luminous efficiency

Technical field

This application involves LED growth technology fields, specifically, being related to a kind of LED extension of improving luminous efficiency Growing method.

Background technique

LED is as lighting source with low energy consumption, the service life is long, small in size, shine effect compared with existing conventional illumination source The advantages that rate is high, pollution-free and rich in color.The scale of domestic production LED gradually expands at present, need of the market to LED It asks and the demand of LED light effect is all growing day by day.

That there are current densities is higher by LED at present, the luminous efficiency of LED chip lower " decaying (droop) phenomenon ", therefore Energy loss can become larger, and influence the energy-saving effect of LED.Inhibiting the luminous efficiency of this relaxation phenomenon, promotion LED becomes industry most The problem of to pay close attention to.

Therefore, it in view of the above-mentioned problems, the present invention provides a kind of LED epitaxial growth method of improving luminous efficiency, solves existing There is luminous efficiency decaying (efficiency droop) problem under Bulk current injection present in LED epitaxial growth.

Summary of the invention

In view of this, the technical problem to be solved by the application is to provide a kind of lifes of the LED extension of improving luminous efficiency Long method solves the luminous efficiency decaying (efficiency under Bulk current injection present in existing LED epitaxial growth Droop) problem.

In order to solve the above-mentioned technical problem, the application has following technical solution: a kind of LED extension of improving luminous efficiency is raw Long method successively includes: the N-type GaN for handling substrate, growing low temperature buffer layer GaN, growing the GaN layer that undopes, growth doping Si Layer, the thin barrier layer of growth InAlN:Mg, alternating growth In_xGa_(1-x)N/GaN luminescent layer, growth InGaAlN superlattices electronic blocking Layer, growing P-type AlGaN layer, the p-type GaN layer of growth doping Mg, cooling down,

The thin barrier layer of the growth InAlN:Mg, further are as follows:

It keeps reaction cavity pressure 400mbar-600mbar, kept for 800 DEG C -900 DEG C of temperature, being passed through flow is The NH of 30000sccm-60000sccm₃, 100sccm-200sccm TMAl, 80L/min-110L/min N₂、800sccm- The CP of the TMIn and 1200sccm-1500sccm of 1000sccm₂Mg, the InAIN layer for the doping Mg that growth thickness is 5nm-12nm, Form the thin barrier layer of InAlN:Mg, wherein Mg doping concentration is 5E17atoms/cm³-8E17atoms/cm³；

The growth InGaAlN superlattices electronic barrier layer, further are as follows:

Reaction cavity pressure 850mbar-950mbar is kept, is kept for 750 DEG C -900 DEG C of temperature, being passed through flow is The NH of 50000sccm-55000sccm₃, 70sccm-90sccm TMGa, 110L/min-150L/min H₂、1400sccm- The TMIn of the TMAl and 1000sccm-1400sccm of 1700sccm grow the InGaAlN superlattices electronic blocking of 12nm-25nm Layer.

Preferably, the processing substrate, further are as follows:

In 1000 DEG C -1100 DEG C of H₂Under atmosphere, it is passed through the H of 100L/min-130L/min₂, keep reaction cavity pressure 100mbar-300mbar handles Sapphire Substrate 5min-10min.

Preferably, the growing low temperature buffer layer GaN, further are as follows:

500 DEG C -600 DEG C are cooled to, reaction cavity pressure 300mbar-600mbar is kept, being passed through flow is 10000sccm- The NH of 20000sccm₃, 50sccm-100sccm TMGa and 100L/min-130L/min H₂, grow on a sapphire substrate With a thickness of the low temperature buffer layer GaN of 20nm-40nm；

1000 DEG C -1100 DEG C are increased the temperature to, keeps reaction cavity pressure 300mbar-600mbar, being passed through flow is The NH of 30000sccm-40000sccm₃, 100L/min-130L/min H₂, 300s-500s is kept the temperature, low temperature buffer layer GaN is rotten Lose into irregular island shape.

Preferably, described to grow the GaN layer that undopes, further are as follows:

1000 DEG C -1200 DEG C are increased the temperature to, keeps reaction cavity pressure 300mbar-600mbar, being passed through flow is The NH of 30000sccm-40000sccm₃, 200sccm-400sccm TMGa and 100L/min-130L/min H₂, continued propagation 2 μm -4 μm of the GaN layer that undopes.

Preferably, the N-type GaN layer of the growth doping Si, further are as follows:

Reaction cavity pressure 300mbar-600mbar is kept, is kept for 1000 DEG C -1200 DEG C of temperature, being passed through flow is The NH of 30000sccm-60000sccm₃, 200sccm-400sccm TMGa, 100L/min-130L/min H₂And 20sccm- The SiH of 50sccm₄, the N-type GaN of 3 μm of -4 μm of doping Si of continued propagation, wherein Si doping concentration 5E18atoms/cm³- 1E19atoms/cm³；

Reaction cavity pressure, temperature-resistant is kept, the NH that flow is 30000sccm-60000sccm is passed through₃、200sccm- The H of TMGa, 100L/min-130L/min of 400sccm₂And the SiH of 2sccm-10sccm₄, continued propagation 200nm-400nm mixes The N-type GaN of miscellaneous Si, wherein Si doping concentration 5E17atoms/cm³-1E18atoms/cm³。

Preferably, the alternating growth In_xGa_(1-x)N/GaN luminescent layer, further are as follows:

It keeps reaction cavity pressure 300mbar-400mbar, kept for 700 DEG C -750 DEG C of temperature, being passed through flow is The NH of 50000sccm-70000sccm₃, 20sccm-40sccm TMGa, 1500sccm-2000sccm TMIn and 100L/ The N of min-130L/min₂, the In of the 2.5nm-3.5nm of growth doping In_xGa_(1-x)N layers, wherein x=0.20-0.25 shines Wavelength is 450nm-455nm；

Temperature is increased to 750 DEG C -850 DEG C, keeps reaction cavity pressure 300mbar-400mbar, being passed through flow is The NH of 50000sccm-70000sccm₃, 20sccm-100sccm TMGa and 100L/min-130L/min N₂, grow 8nm- The GaN layer of 15nm；

Repeat alternating growth In_xGa_(1-x)N layers and GaN layer, obtain In_xGa_(1-x)N/GaN luminescent layer, wherein In_xGa_(1-x)N Layer and the alternating growth periodicity of GaN layer are 7-15.

Preferably, the growing P-type AlGaN layer, further are as follows:

Reaction cavity pressure 200mbar-400mbar, 900 DEG C -950 DEG C of temperature are kept, being passed through flow is 50000sccm- The NH of 70000sccm₃, 30sccm-60sccm TMGa, 100L/min-130L/min H₂, 100sccm-130sccm TMAl And the Cp of 1000sccm-1300sccm₂The p-type AlGaN layer of Mg, continued propagation 50nm-100nm, wherein Al doping concentration 1E20atoms/cm³-3E20atoms/cm³, Mg doping concentration 1E19atoms/cm³-1E20atoms/cm³。

Preferably, described to grow the p-type GaN layer for mixing Mg, further are as follows:

Reaction cavity pressure 400mbar-900mbar, 950 DEG C -1000 DEG C of temperature are kept, being passed through flow is 50000sccm- The NH of 70000sccm₃, 20sccm-100sccm TMGa, 100L/min-130L/min H₂And 1000sccm-3000sccm Cp₂The p-type GaN layer for mixing Mg of Mg, continued propagation 50nm-200nm, wherein Mg doping concentration 1E19atoms/cm³- 1E20atoms/cm³。

Preferably, the cooling down, further are as follows:

650 DEG C -680 DEG C are cooled to, 20min-30min is kept the temperature, heating system is closed, closes and give gas system, furnace cooling.

Compared with prior art, method described herein, reached it is following the utility model has the advantages that

(1) in the LED epitaxial growth method of improving luminous efficiency of the present invention, the two of InGaN/GaN mqw light emitting layer Side grows the thin barrier layer of InAlN:Mg and InGaAlN superlattices electronic barrier layer, so that the InGaN and GaN of luminescent layer reach respectively The defects of state of complete relaxation, lattice mismatch bring stress are substantially achieved elimination, the dislocation that when crystal growth generates is significantly It reduces, Wave function overlap degree of the electrons and holes in the space K (k-space is dual spaces of the ordinary space under fourier conversion) Increase, the photon number of compound generation increases in the unit time, so that the luminous efficiency of LED is improved, antistatic energy Power enhancing.

(2) in the LED epitaxial growth method of improving luminous efficiency of the present invention, by conventional LED epitaxial growth method Before growing InGaN/GaN mqw light emitting layer, the thin barrier layer of InAlN:Mg is first grown, can be provided compared with the sub- trap of multi-hole inlet Hole mobility is improved in region, pushes the sub- trap luminous zone of hole injection fluence, improves the hole injection water of entire quantum well region It is flat, the luminous combined efficiency in hole and electronics is improved, and then improve the luminous efficiency of LED.

(3) in the LED epitaxial growth method of improving luminous efficiency of the present invention, by conventional LED epitaxial growth method After growing InGaN/GaN mqw light emitting layer, InGaAlN superlattices electronic barrier layer is grown, due to InGaAlN superlattices electricity Sub- barrier layer has biggish forbidden bandwidth, so that the effective barrier height that quantum is built is improved, can effectively fetter simultaneously Stop electronics to overflow out of Quantum Well, inhibit the generation of electron leak electric current, and then promotes note of the electrons and holes in Quantum Well Enter efficiency, improves the luminous efficiency of LED.In addition, the electronic barrier layer also can effectively solve electrons and holes congestion effect, improve Voltage, luminous efficiency decaying (efficiency droop) problem by promoting brightness and improving voltage, under Bulk current injection It is well solved.

Certainly, implementing any of the products of the present invention specific needs while must not reach all the above technical effect.

By referring to the drawings to the detailed description of exemplary embodiment of the present invention, other feature of the invention and its Advantage will become apparent.

Detailed description of the invention

It is combined in the description and the attached drawing for constituting part of specification shows the embodiment of the present invention, and even With its explanation together principle for explaining the present invention.

Fig. 1 is the structural schematic diagram of the LED epitaxial layer of improving luminous efficiency described in the embodiment of the present invention 1；

Fig. 2 is the structural schematic diagram of the LED epitaxial layer of improving luminous efficiency described in the embodiment of the present invention 2；

Fig. 3 is the structural schematic diagram of routine LED epitaxial layer.

Specific embodiment

Carry out the various exemplary embodiments of detailed description of the present invention now with reference to attached drawing.It should also be noted that unless in addition having Body explanation, the unlimited system of component and the positioned opposite of step, numerical expression and the numerical value otherwise illustrated in these embodiments is originally The range of invention.

Be to the description only actually of at least one exemplary embodiment below it is illustrative, never as to the present invention And its application or any restrictions used.

Technology, method and apparatus known to person of ordinary skill in the relevant may be not discussed in detail, but suitable In the case of, the technology, method and apparatus should be considered as part of specification.

It is shown here and discuss all examples in, any occurrence should be construed as merely illustratively, without It is as limitation.Therefore, other examples of exemplary embodiment can have different values.

It should also be noted that similar label and letter indicate similar terms in following attached drawing, therefore, once a certain Xiang Yi It is defined in a attached drawing, then in subsequent attached drawing does not need that it is further discussed.

The present invention grows high brightness GaN-based LED epitaxial wafer with MOCVD.Using high-purity H₂Or high-purity N₂Or high-purity H₂With High-purity N₂Mixed gas as carrier gas, high-purity N H₃As the source N, metal organic source trimethyl gallium (TMGa) is used as gallium source, front three Base indium (TMIn) is used as indium source, and N type dopant is silane (SiH₄), trimethyl aluminium (TMAl) is used as silicon source, P-type dopant two Luxuriant magnesium (CP₂Mg), substrate be (0001) surface sapphire, reaction pressure 70mbar to 900mbar (mbar is the barometric millimeter of mercury) it Between.The present invention solves the decaying of the luminous efficiency under Bulk current injection present in existing LED epitaxial growth (efficiency Droop) problem.

Embodiment 1

The LED epitaxial growth method for enhancing luminous radiation efficiency described in the present embodiment, includes the following steps:

Step 101, processing Sapphire Substrate.

Step 102, growing low temperature buffer layer GaN.

Step 103 grows the GaN layer that undopes.

The N-type GaN layer of step 104, growth doping Si.

Step 105, the growth thin barrier layer of InAlN:Mg, further are as follows:

It keeps reaction cavity pressure 400mbar-600mbar, kept for 800 DEG C -900 DEG C of temperature, being passed through flow is The NH of 30000sccm-60000sccm₃, 100sccm-200sccm TMAl, 80L/min-110L/min N₂、800sccm- The CP of the TMIn and 1200sccm-1500sccm of 1000sccm₂Mg, the InAIN layer for the doping Mg that growth thickness is 5nm-12nm, Form the thin barrier layer of InAlN:Mg, wherein Mg doping concentration is 5E17atoms/cm³-8E17atoms/cm³(1E17 represents 10 17 powers, that is, 10¹⁷, 5E17 represents 5 × 10¹⁷, atoms/cm³For concentration unit, following presentation mode and so on).

Step 106, alternating growth In_xGa_(1-x)N/GaN luminescent layer.

In_xGa_(1-x)N/GaN luminescent layer, as InGaN/GaN Quantum Well.

Step 107, growth InGaAlN superlattices electronic barrier layer, further are as follows:

Step 108, growing P-type AlGaN layer.

The p-type GaN layer of step 109, growth doping Mg.

Step 110, cooling down.

Luminous efficiency at present using the LED of routine LED epitaxial growth technology preparation is not still high, increases with driving current Add, luminous efficiency relaxation phenomenon is more serious.In the LED epitaxial growth method of improving luminous efficiency of the present invention, in InGaN/GaN The two sides of mqw light emitting layer grow the thin barrier layer of InAlN:Mg and InGaAlN superlattices electronic barrier layer, so that luminescent layer respectively InGaN and GaN reach the state of complete relaxation, lattice mismatch bring stress is substantially achieved elimination, and when crystal growth generates Dislocation the defects of greatly reduce, electrons and holes are in the space the K (dual-space that k-space is ordinary space under fourier conversion Between) Wave function overlap degree increase, the photon number of compound generation increases in the unit time, so that the luminous efficiency of LED It is improved, antistatic effect enhancing；Pass through the growth InGaN/GaN mqw light emitting layer in conventional LED epitaxial growth method Before, the thin barrier layer of InAlN:Mg is first grown, can provide compared with the sub- well area of multi-hole inlet, improve hole mobility, push The sub- trap luminous zone of hole injection fluence, improves the hole Injection Level of entire quantum well region, improves the luminous multiple of hole and electronics Efficiency is closed, and then improves the luminous efficiency of LED；Pass through the growth InGaN/GaN Quantum Well hair in conventional LED epitaxial growth method After photosphere, InGaAlN superlattices electronic barrier layer is grown, since InGaAlN superlattices electronic barrier layer has biggish taboo Bandwidth can be fettered effectively so that the effective barrier height that quantum is built is improved and electronics is stopped to overflow out of Quantum Well Out, inhibit the generation of electron leak electric current, and then promote injection efficiency of the electrons and holes in Quantum Well, improve shining for LED Efficiency.In addition, the electronic barrier layer also can effectively solve electrons and holes congestion effect, improve voltage, by promoted brightness and Improve voltage, luminous efficiency decaying (efficiency droop) problem under Bulk current injection is well solved.

As shown in Figure 1, be prepared for the LED epitaxial growth method using improving luminous efficiency described in the present embodiment The structural schematic diagram of LED epitaxial layer, the LED are comprised the following structure: substrate 101, low temperature buffer layer GaN102, undope GaN layer 103, N-type GaN layer 104, the thin barrier layer 105 of InAlN:Mg, In of Si are adulterated_xGa_(1-x)N/GaN luminescent layer 106 (wherein, including is handed over Folded: In_xGa_(1-x)N layer 161 and GaN layer 162), InGaAlN superlattices electronic barrier layer 107, AlGaN layer 108 and doping Mg P-type GaN layer 109.

Embodiment 2

The particular content of whole growth LED epitaxial layer has been described in detail in the present embodiment, promotes the effect that shines described in the present embodiment The LED epitaxial growth method of rate, includes the following steps:

Step 201, processing Sapphire Substrate: to the reaction chamber for the Metallo-Organic Chemical Vapor depositing system for being placed with substrate It is interior, in 1000 DEG C -1100 DEG C of H₂Under atmosphere, it is passed through the H of 100L/min-130L/min₂, keep reaction cavity pressure 100mbar- 300mbar handles Sapphire Substrate 5min-10min.

Step 202, growing low temperature buffer layer GaN: being cooled to 500 DEG C -600 DEG C, keeps reaction cavity pressure 300mbar- 600mbar is passed through the NH that flow is 10000sccm-20000sccm₃, 50sccm-100sccm TMGa and 100L/min- The H of 130L/min₂, growth thickness is the low temperature buffer layer GaN of 20nm-40nm on a sapphire substrate.

Step 203 grows the GaN layer that undopes: increasing the temperature to 1000 DEG C -1200 DEG C, keeps reaction cavity pressure 300mbar-600mbar is passed through the NH that flow is 30000sccm-40000sccm₃, 200sccm-400sccm TMGa and The H of 100L/min-130L/min₂, 2 μm -4 μm of continued propagation of the GaN layer that undopes.

The N-type GaN layer of step 204, growth doping Si: reaction cavity pressure 300mbar-600mbar is kept, temperature is kept 1000 DEG C -1200 DEG C, it is passed through the NH that flow is 30000sccm-60000sccm₃, 200sccm-400sccm TMGa, 100L/ The H of min-130L/min₂And the SiH of 20sccm-50sccm₄, the N-type GaN of 3 μm of -4 μm of doping Si of continued propagation, wherein Si mixes Miscellaneous concentration 5E18atoms/cm³-1E19atoms/cm³；

Step 205, the growth thin barrier layer of InAlN:Mg: it keeps reaction cavity pressure 400mbar-600mbar, keep temperature 800 DEG C -900 DEG C, it is passed through the NH that flow is 30000sccm-60000sccm₃, 100sccm-200sccm TMAl, 80L/min- The N of 110L/min₂, 800sccm-1000sccm TMIn and 1200sccm-1500sccm CP₂Mg, growth thickness 5nm- The InAIN layer of the doping Mg of 12nm, forms the thin barrier layer of InAlN:Mg, wherein Mg doping concentration is 5E17atoms/cm³- 8E17atoms/cm³。

Step 206, alternating growth In_xGa_(1-x)N/GaN luminescent layer: it keeps reaction cavity pressure 300mbar-400mbar, protect 700 DEG C -750 DEG C of temperature are held, the NH that flow is 50000sccm-70000sccm is passed through₃, 20sccm-40sccm TMGa, The N of the TMIn and 100L/min-130L/min of 1500sccm-2000sccm₂, the 2.5nm-3.5nm's of growth doping In In_xGa_(1-x)N layers, wherein x=0.20-0.25, emission wavelength 450nm-455nm.

Temperature is increased to 750 DEG C -850 DEG C, keeps reaction cavity pressure 300mbar-400mbar, being passed through flow is The NH of 50000sccm-70000sccm₃, 20sccm-100sccm TMGa and 100L/min-130L/min N₂, grow 8nm- The GaN layer of 15nm.Repeat alternating growth In_xGa_(1-x)N layers and GaN layer, obtain In_xGa_(1-x)N/GaN luminescent layer, wherein In_xGa_(1-x)N layers a for 7-15 with the alternating growth periodicity of GaN layer.

Step 207, the growth InGaAlN superlattices electronic barrier layer: reaction cavity pressure 850mbar- is kept 950mbar is kept for 750 DEG C -900 DEG C of temperature, is passed through the NH that flow is 50000sccm-55000sccm₃、70sccm-90sccm TMGa, 110L/min-150L/min H₂, 1400sccm-1700sccm TMAl and 1000sccm-1400sccm TMIn grows the InGaAlN superlattices electronic barrier layer of 12nm-25nm.

Step 208, growing P-type AlGaN layer: keeping reaction cavity pressure 200mbar-400mbar, 900 DEG C -950 DEG C of temperature, It is passed through the NH that flow is 50000sccm-70000sccm₃, 30sccm-60sccm TMGa, 100L/min-130L/min H₂、 The Cp of the TMAl and 1000sccm-1300sccm of 100sccm-130sccm₂The p-type AlGaN of Mg, continued propagation 50nm-100nm Layer, wherein Al doping concentration 1E20atoms/cm³-3E20atoms/cm³, Mg doping concentration 1E19atoms/cm³- 1E20atoms/cm³。

The p-type GaN layer of step 209, growth doping Mg: reaction cavity pressure 400mbar-900mbar, 950 DEG C of temperature-are kept 1000 DEG C, it is passed through the NH that flow is 50000sccm-70000sccm₃, 20sccm-100sccm TMGa, 100L/min-130L/ The H of min₂And the Cp of 1000sccm-3000sccm₂The p-type GaN layer for mixing Mg of Mg, continued propagation 50nm-200nm, wherein Mg mixes Miscellaneous concentration 1E19atoms/cm³-1E20atoms/cm³。

Step 210, cooling down: being cooled to 650 DEG C -680 DEG C, keeps the temperature 20min-30min, closes heating system, closes Gas system is given, furnace cooling obtains light emitting diode.

As shown in Fig. 2, be prepared for the LED epitaxial growth method using improving luminous efficiency described in the present embodiment The structural schematic diagram of LED epitaxial layer, the LED are comprised the following structure: substrate 201, low temperature buffer layer GaN202, undope GaN layer 203, N-type GaN layer 204, the thin barrier layer 205 of InAlN:Mg, In of Si are adulterated_xGa_(1-x)N/GaN luminescent layer 206 (wherein, including is handed over Folded: In_xGa_(1-x)N layer 261 and GaN layer 262), InGaAlN superlattices electronic barrier layer 207, p-type AlGaN layer 208 and doping The p-type GaN layer 209 of Mg.

The LED epitaxial growth method of improving luminous efficiency described in the present embodiment, the two of InGaN/GaN quantum well structure Side, grows the thin barrier layer of the thin barrier layer of InAlN:Mg and InGaAlN superlattices electronic barrier layer respectively, the luminous efficiency of Lai Tisheng LED, Solve the problems, such as the luminous efficiency decaying (efficiency droop) under Bulk current injection present in existing LED epitaxial growth.

Embodiment 3

A kind of routine LED epitaxial growth method presented below is as comparative example of the invention.

Conventional LED epitaxial growth method, includes the following steps:

Step 301, processing Sapphire Substrate: to the reaction chamber for the Metallo-Organic Chemical Vapor depositing system for being placed with substrate It is interior, in 1000 DEG C -1100 DEG C of H₂Under atmosphere, it is passed through the H of 100L/min-130L/min₂, keep reaction cavity pressure 100mbar- 300mbar handles Sapphire Substrate 5min-10min.

Step 302, growing low temperature buffer layer GaN: being cooled to 500 DEG C -600 DEG C, keeps reaction cavity pressure 300mbar- 600mbar is passed through the NH that flow is 10000sccm-20000sccm₃, 50sccm-100sccm TMGa and 100L/min- The H of 130L/min₂, growth thickness is the low temperature buffer layer GaN of 20nm-40nm on a sapphire substrate.

Step 303 grows the GaN layer that undopes: increasing the temperature to 1000 DEG C -1200 DEG C, keeps reaction cavity pressure 300mbar-600mbar is passed through the NH that flow is 30000sccm-40000sccm₃, 200sccm-400sccm TMGa and The H of 100L/min-130L/min₂, 2 μm -4 μm of continued propagation of the GaN layer that undopes.

The N-type GaN layer of step 304, growth doping Si: reaction cavity pressure 300mbar-600mbar is kept, temperature is kept 1000 DEG C -1200 DEG C, it is passed through the NH that flow is 30000sccm-60000sccm₃, 200sccm-400sccm TMGa, 100L/ The H of min-130L/min₂And the SiH of 20sccm-50sccm₄, the N-type GaN of 3 μm of -4 μm of doping Si of continued propagation, wherein Si mixes Miscellaneous concentration 5E18atoms/cm³-1E19atoms/cm³；

Step 305, alternating growth In_xGa_(1-x)N/GaN luminescent layer: it keeps reaction cavity pressure 300mbar-400mbar, protect 700 DEG C -750 DEG C of temperature are held, the NH that flow is 50000sccm-70000sccm is passed through₃, 20sccm-40sccm TMGa, The N of the TMIn and 100L/min-130L/min of 1500sccm-2000sccm₂, the 2.5nm-3.5nm's of growth doping In In_xGa_(1-x)N layers, wherein x=0.20-0.25, emission wavelength 450nm-455nm.

Step 306, growing P-type AlGaN layer: keeping reaction cavity pressure 200mbar-400mbar, 900 DEG C -950 DEG C of temperature, It is passed through the NH that flow is 50000sccm-70000sccm₃, 30sccm-60sccm TMGa, 100L/min-130L/min H₂、 The Cp of the TMAl and 1000sccm-1300sccm of 100sccm-130sccm₂The p-type AlGaN of Mg, continued propagation 50nm-100nm Layer, wherein Al doping concentration 1E20atoms/cm³-3E20atoms/cm³, Mg doping concentration 1E19atoms/cm³- 1E20atoms/cm³。

The p-type GaN layer of step 307, growth doping Mg: reaction cavity pressure 400mbar-900mbar, 950 DEG C of temperature-are kept 1000 DEG C, it is passed through the NH that flow is 50000sccm-70000sccm₃, 20sccm-100sccm TMGa, 100L/min-130L/ The H of min₂And the Cp of 1000sccm-3000sccm₂The p-type GaN layer for mixing Mg of Mg, continued propagation 50nm-200nm, wherein Mg mixes Miscellaneous concentration 1E19atoms/cm³-1E20atoms/cm³。

Step 308, cooling down: being cooled to 650 DEG C -680 DEG C, keeps the temperature 20min-30min, closes heating system, closes Gas system is given, furnace cooling obtains light emitting diode.

As shown in figure 3, the LED epitaxial layer being prepared using routine techniques epitaxial growth method, includes such as from the bottom to top Flowering structure: substrate 301, low temperature buffer layer GaN302, the GaN layer that undopes 303, the N-type GaN layer 304 for adulterating Si, In_xGa_(1-x)N/ GaN luminescent layer 305 is (wherein, including overlapping: In_xGa_(1-x)N layer 351 and GaN layer 352), p-type AlGaN layer 306 and doping Mg P-type GaN layer 307.

Sample 1 is prepared according to conventional LED epitaxial growth method (method of comparative example 3), is described according to this patent Method prepare sample 2；The difference of 2 epitaxial growth method of sample 1 and sample is: the growth of sample 2 has the thin base InAlN:Mg Layer and InGaAlN superlattices electronic barrier layer, other outer layer growth conditions are just the same；Sample 1 and sample 2 are before identical ITO layer about 150nm is plated under process conditions, plates Cr/Pt/Au electrode about 1500nm under the same conditions, and plating is protected under the same conditions Sheath SiO₂About 100nm, then at identical conditions by sample grinding and cutting at 635 μm * 635 μm (25mil*25mil) Chip particle, then sample 1 and sample 2 respectively select 100 crystal grain in same position, under identical packaging technology, encapsulation At white light LEDs.Then the photoelectric properties of integrating sphere test sample 1 and sample 2 under the conditions of driving current 350mA are used.Below Table 1 is the comparison sheet of sample 1,2 product electrical parameters.

The comparison sheet of 1 sample 1 of table, 2 product electrical parameters

It can be concluded that by the data of table 1

The data that integrating sphere obtains are subjected to analysis comparison, please refer to table 1, from table 1 it follows that

The growing method LED luminous efficiency that this patent provides is obviously improved, and antistatic property gets a promotion, other Every LED electrical parameter becomes excellent, and experimental data, which demonstrates this patent scheme, can promote the feasibility of LED product luminous efficiency.

As can be seen from the above embodiments beneficial effect existing for the application is:

It should be understood by those skilled in the art that, the embodiment of the present invention can provide as method, apparatus or computer program Product.Therefore, complete hardware embodiment, complete software embodiment or reality combining software and hardware aspects can be used in the present invention Apply the form of example.Moreover, it wherein includes the computer of computer usable program code that the present invention, which can be used in one or more, The computer program implemented in usable storage medium (including but not limited to magnetic disk storage, CD-ROM, optical memory etc.) produces The form of product.

The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, for the skill of this field For art personnel, the invention may be variously modified and varied.All within the spirits and principles of the present invention, made any to repair Change, equivalent replacement, improvement etc., should all be included in the protection scope of the present invention.

Claims

1. a kind of LED epitaxial growth method of improving luminous efficiency, successively include: processing substrate, growing low temperature buffer layer GaN, Grow the GaN layer that undopes, the N-type GaN layer of growth doping Si, the thin barrier layer of growth InAlN:Mg, alternating growth In_xGa_(1-x)N/GaN Luminescent layer, growth InGaAlN superlattices electronic barrier layer, growing P-type AlGaN layer, the p-type GaN layer of growth doping Mg, cool down cold But, which is characterized in that

The thin barrier layer of the growth InAlN:Mg, further are as follows:

It keeps reaction cavity pressure 400mbar-600mbar, kept for 800 DEG C -900 DEG C of temperature, being passed through flow is 30000sccm- The NH of 60000sccm₃, 100sccm-200sccm TMAl, 80L/min-110L/min N₂, 800sccm-1000sccm The CP of TMIn and 1200sccm-1500sccm₂Mg, the InAIN layer for the doping Mg that growth thickness is 5nm-12nm, forms InAlN: The thin barrier layer of Mg, wherein Mg doping concentration is 5E17atoms/cm³-8E17atoms/cm³；

Reaction cavity pressure 850mbar-950mbar is kept, is kept for 750 DEG C -900 DEG C of temperature, being passed through flow is 50000sccm- The NH of 55000sccm₃, 70sccm-90sccm TMGa, 110L/min-150L/min H₂, 1400sccm-1700sccm The TMIn of TMAl and 1000sccm-1400sccm grows the InGaAlN superlattices electronic barrier layer of 12nm-25nm.

2. the LED epitaxial growth method of improving luminous efficiency according to claim 1, which is characterized in that the processing substrate, Further are as follows:

In 1000 DEG C -1100 DEG C of H₂Under atmosphere, it is passed through the H of 100L/min-130L/min₂, keep reaction cavity pressure 100mbar- 300mbar handles Sapphire Substrate 5min-10min.

3. the LED epitaxial growth method of improving luminous efficiency according to claim 1, which is characterized in that the growing low temperature Buffer layer GaN, further are as follows:

4. the LED epitaxial growth method of improving luminous efficiency according to claim 1, which is characterized in that the growth is not mixed Miscellaneous GaN layer, further are as follows:

5. the LED epitaxial growth method of improving luminous efficiency according to claim 1, which is characterized in that the growth doping The N-type GaN layer of Si, further are as follows:

Reaction cavity pressure 300mbar-600mbar is kept, is kept for 1000 DEG C -1200 DEG C of temperature, being passed through flow is 30000sccm- The NH of 60000sccm₃, 200sccm-400sccm TMGa, 100L/min-130L/min H₂And 20sccm-50sccm SiH₄, the N-type GaN of 3 μm of -4 μm of doping Si of continued propagation, wherein Si doping concentration 5E18atoms/cm³-1E19atoms/cm³；

Reaction cavity pressure, temperature-resistant is kept, the NH that flow is 30000sccm-60000sccm is passed through₃、200sccm-400sccm TMGa, 100L/min-130L/min H₂And the SiH of 2sccm-10sccm₄, the N of continued propagation 200nm-400nm doping Si Type GaN, wherein Si doping concentration 5E17atoms/cm³-1E18atoms/cm³。

6. the LED epitaxial growth method of improving luminous efficiency according to claim 1, which is characterized in that the alternating growth In_xGa_(1-x)N/GaN luminescent layer, further are as follows:

It keeps reaction cavity pressure 300mbar-400mbar, kept for 700 DEG C -750 DEG C of temperature, being passed through flow is 50000sccm- The NH of 70000sccm₃, 20sccm-40sccm TMGa, 1500sccm-2000sccm TMIn and 100L/min-130L/min N₂, the In of the 2.5nm-3.5nm of growth doping In_xGa_(1-x)N layers, wherein x=0.20-0.25, emission wavelength 450nm- 455nm；

Temperature is increased to 750 DEG C -850 DEG C, keeps reaction cavity pressure 300mbar-400mbar, being passed through flow is 50000sccm- The NH of 70000sccm₃, 20sccm-100sccm TMGa and 100L/min-130L/min N₂, grow the GaN of 8nm-15nm Layer；

Repeat alternating growth In_xGa_(1-x)N layers and GaN layer, obtain In_xGa_(1-x)N/GaN luminescent layer, wherein In_xGa_(1-x)N layers and The alternating growth periodicity of GaN layer is 7-15.

7. the LED epitaxial growth method of improving luminous efficiency according to claim 1, which is characterized in that the growing P-type AlGaN layer, further are as follows:

8. the LED epitaxial growth method of improving luminous efficiency according to claim 1, which is characterized in that Mg is mixed in the growth P-type GaN layer, further are as follows:

9. the LED epitaxial growth method of improving luminous efficiency according to claim 1, which is characterized in that the cooling down, Further are as follows: