A kind of LED structure of Si bases GaN and preparation method thereof
Technical field
The present invention relates to LED (Light Emitting Diode, light emitting diode) manufactures field, in particular relate to
And a kind of Si (silicon) underlayer nitriding gallium GaN base LED structure and preparation method thereof.
Background technology
This emerging concept of energy-conserving and environment-protective is also in LED (Light Emitting Diode, hair since with entrance 21 century
Optical diode) industry starts to warm up.And the White light LED technology of device has also been obtained rapidly based on GaN (gallium nitride) bases LED
Development.Reached more than 130 lumens/watts using GaN blue-light LED chips as the white light LEDs list light source efficiency of excitaton source, much
The light efficiency of common energy-saving lamp is exceeded, LED technology has started to enter general illumination market comprehensively.With GaN base LED ranges of application
Further expansion, requirement to LED component luminous efficiency also more and more higher, various new epitaxy methods, new chip manufacturing
Technique, new device architecture are constantly weeded out the old and bring forth the new, or lift the utilization ratio of existing structure, and constantly lifting is reached with this
GaN LED light extraction efficiencies and the purpose for going out light characteristic.
At present, in the prior art, a kind of method of main raising light extraction efficiency is to prepare one layer of hair in LED most surfaces
The surface of change is reducing the total reflection of GaN material and Air Interface.However it is necessary that extra recipe step.For vertical junction
The LED of structure, processing step is just more cumbersome.
The content of the invention
In view of this, the invention provides a kind of Si (silicon) substrate GaN-based LED structure and preparation method thereof, served as a contrast using Si
The crackle of big lattice mismatch and thermal mismatching formed in cushion between bottom and GaN, as the diffusing reflection area of LED light extractions,
To reach the purpose of the luminous efficiency for improving gallium nitride based light emitting diode.
To achieve the above object, the present invention provides following technical scheme, a kind of silicon substrate gallium nitride based light emitting diode LED
Structure, its epitaxial structure includes Si substrates 1, the first high-temperature AlN 2, content gradually variational AlGaN or AlN/GaN superlattices 3, the successively
Two high-temperature AlNs 4, GaN non-doped layers 5, p-type contact layer 6, high temperature p-type GaN layer 7, P-type electron barrier layer 8, multiple quantum well layer 9, N
Type GaN layer 10;First high-temperature AlN 2, content gradually variational AlGaN or AlN/GaN superlattices 3, the three of the composition of the second high-temperature AlN 4
Mingzhi's textured buffer layers.
A kind of silicon substrate gallium nitride based light emitting diode LED structure preparation method, its epitaxial structure genesis sequence includes Si
Substrate 1, the first high-temperature AlN 2, content gradually variational AlGaN or AlN/GaN superlattices 3, the second high-temperature AlN 4, GaN non-doped layers 5, P
Type contact layer 6, high temperature p-type GaN layer 7, P-type electron barrier layer 8, multiple quantum well layer 9, N-type GaN layer 10;First high temperature
AlN2, content gradually variational AlGaN or AlN/GaN superlattices 3, the sandwich structure cushion of the composition of the second high-temperature AlN 4.
The growth thickness of first high-temperature AlN 2 is 60-100nm, and growth temperature is 1050-1150 DEG C, growth pressure 50-
200torr。
Two growth conditions up and down in sandwich structure are consistent.The Al groups of the graded component AlGaN of sandwich layer
Dividing has 1 gradual change to 0, or AlN/GaN superlattices parameter is 2nm/2nm, 20-30 cycle.Sandwich of layers gross thickness 1um with
It is interior.
The described thickness of GaN non-doped layers 5 is 1-1.2 μm, and between 1000-1200 DEG C, pressure is in 100- for growth temperature
Between 600Torr, V/III than being 100-3000.
The described thickness of p-type contact layer 6 is 5-20nm, and between 850-1050 DEG C, growth time is 1- to growth temperature
10min, between 100-500Torr, V/III than being 1000-20000 for pressure.
Between 850-950 DEG C, growth time is 5-30min to the described growth temperature of high temperature p-type GaN layer 7, and pressure exists
Between 100-500Torr, V/III than being 300-5000.
The described growth thickness of P-type electron barrier layer 8 is p-type AlGaInN layer of 20-70nm, and growth temperature is in 700-
Between 1100 DEG C, between 100-600Torr, V/III than being 100-3000 for pressure;
Described multiple quantum well layer 9 includes the successively overlapping quantum well structures of 3-15, the quantum well structure by
InxGa1-xN(0<x<1) potential well layer and GaN barrier layers grow form successively, and the growth temperature of the InxGa1-xN potential well layers exists
Between 720-820 DEG C, between 100-500Torr, V/III than being 300-5000, and thickness is between 2-5nm for pressure.
The described thickness of N-type GaN layer 10 is 1.2-1.5 μm, and between 1000-1200 DEG C, pressure is in 100- for growth temperature
Between 600Torr, V/III than being 100-3000;Sandwich buffer layer structure needs stress relaxation to form crackle last.
The gallium nitride based light emitting diode LED of the Si substrates 1 and growing method are with high-purity hydrogen (H2) or nitrogen (N2) conduct
Carrier gas, with trimethyl gallium (TMGa), triethyl-gallium (TEGa) and ammonia (NH3) respectively as Ga and N sources, with silane (SiH4) and
Two luxuriant magnesium (CP2Mg) respectively as N, P-type dopant.
Compared with disclosed technology, there is advantages below in the present invention:Sandwich buffer layer structure is with sandwich of layers in the present invention
The form for forming crackle alleviates the lattice mismatch and thermal mismatching between structural material and Si substrates, at the same substrate desquamation it
Afterwards, the diffusing reflection area of light is formed on p-type GaN surfaces so as to effectively improve the luminous efficiency of gallium nitride based light emitting diode.PN-
GaN structures are inverted growth, are conducive to the treatment of p-type GaN electrodes after transfer substrate upside-down mounting.
Brief description of the drawings
Fig. 1 is LED epitaxial structure schematic diagram of the invention.
Fig. 2 is inverted structure schematic diagram.
In figure:1st, Si substrates, 2, high-temperature AlN, 3, content gradually variational AlGaN or AlN/GaN superlattices, the 4, second high-temperature AlN,
5th, GaN non-doped layers, 6, p-type contact layer, 7, high temperature p-type GaN layer, 8, P-type electron barrier layer, 9, multiple quantum well layer, 10, N-type
GaN layer, 11, P electrode.
Specific embodiment
As shown in Figure 1-2, a kind of silicon substrate gallium nitride based light emitting diode LED structure, its epitaxial structure includes Si successively
Substrate 1, the first high-temperature AlN 2, content gradually variational AlGaN or AlN/GaN superlattices 3, the second high-temperature AlN 4, GaN non-doped layers 5, P
Type contact layer 6, high temperature p-type GaN layer 7, P-type electron barrier layer 8, multiple quantum well layer 9, N-type GaN layer 10;First high temperature
AlN2, content gradually variational AlGaN or AlN/GaN superlattices 3, the sandwich structure cushion of the composition of the second high-temperature AlN 4;
A kind of silicon substrate gallium nitride based light emitting diode LED structure preparation method, its epitaxial structure genesis sequence includes Si
Substrate 1, the first high-temperature AlN 2, content gradually variational AlGaN or AlN/GaN superlattices 3, the second high-temperature AlN 4, GaN non-doped layers 5, P
Type contact layer 6, high temperature p-type GaN layer 7, P-type electron barrier layer 8, multiple quantum well layer 9, N-type GaN layer 10;First high temperature
AlN2, content gradually variational AlGaN or AlN/GaN superlattices 3, the sandwich structure cushion of the composition of the second high-temperature AlN 4.
The growth thickness of first high-temperature AlN 2 is 60-100nm, and growth temperature is 1050-1150 DEG C, growth pressure 50-
200torr。
Two growth conditions up and down in sandwich structure are consistent.The Al groups of the graded component AlGaN of sandwich layer
Dividing has 1 gradual change to 0, or AlN/GaN superlattices parameter is 2nm/2nm, 20-30 cycle.Sandwich of layers gross thickness 1um with
It is interior.
The described thickness of GaN non-doped layers 5 is 1-1.2 μm, and between 1000-1200 DEG C, pressure is in 100- for growth temperature
Between 600Torr, V/III than being 100-3000.
The described thickness of p-type contact layer 6 is 5-20nm, and between 850-1050 DEG C, growth time is 1- to growth temperature
10min, between 100-500Torr, V/III than being 1000-20000 for pressure.
Between 850-950 DEG C, growth time is 5-30min to the described growth temperature of high temperature p-type GaN layer 7, and pressure exists
Between 100-500Torr, V/III than being 300-5000.
The described growth thickness of P-type electron barrier layer 8 is p-type AlGaInN layer of 20-70nm, and growth temperature is in 700-
Between 1100 DEG C, between 100-600Torr, V/III than being 100-3000 for pressure;
Described multiple quantum well layer 9 includes the successively overlapping quantum well structures of 3-15, the quantum well structure by
InxGa1-xN(0<x<1) potential well layer and GaN barrier layers grow form successively, and the growth temperature of the InxGa1-xN potential well layers exists
Between 720-820 DEG C, between 100-500Torr, V/III than being 300-5000, and thickness is between 2-5nm for pressure.
The described thickness of N-type GaN layer 10 is 1.2-1.5 μm, and between 1000-1200 DEG C, pressure is in 100- for growth temperature
Between 600Torr, V/III than being 100-3000;Sandwich buffer layer structure needs stress relaxation to form crackle last.
The gallium nitride based light emitting diode LED of the Si substrates 1 and growing method are with high-purity hydrogen (H2) or nitrogen (N2) conduct
Carrier gas, with trimethyl gallium (TMGa), triethyl-gallium (TEGa) and ammonia (NH3) respectively as Ga and N sources, with silane (SiH4) and
Two luxuriant magnesium (CP2Mg) respectively as N, P-type dopant.
Inverted growth structure is conducive to the treatment of P electrode 11 in inverted structure.
General principle of the invention, principal character and advantages of the present invention has been shown and described above.The technology of the industry
Personnel it should be appreciated that the present invention is not limited to the above embodiments, simply explanation described in above-described embodiment and specification this
The principle of invention, without departing from the spirit and scope of the present invention, various changes and modifications of the present invention are possible, these changes
Change and improvement all fall within the protetion scope of the claimed invention.Claimed scope of the invention by appending claims and
Its equivalent thereof.