CN103560187B - LED structure epitaxial growth method containing superlattices barrier layer and structure thereof - Google Patents

Abstract

The invention provides a kind of LED structure epitaxial growth method containing superlattices barrier layer and structure thereof, the step growing GaN:Si/GaN superlattices barrier layer in growth luminescent layer mqw layer is: stop being passed through In ion, and liter high-temperature, to 800 850 DEG C, is passed through SiH₄, InxGa in reative cell_{(1 x)}Grow GaN:Si layer on N shell, stop being passed through SiH₄, in reative cell, on GaN:Si layer, grow GaN layer, GaN layer and GaN:Si layer interlaced formation GaN:Si/GaN superlattices barrier layer；SiH₄The time scale being passed through and stop being passed through is 6:1 1:6.The superlattice layer of the luminescent layer GaN barrier layer GaN/GaN:Si of the Si that originally undopes is replaced by the present invention, on the premise of not affecting electric leakage and the luminous intensity of device, the resistance of luminescent layer is reduced so that the driving voltage of device declines.

Description

Epitaxial growth method and structure of LED structure containing superlattice barrier layer

technical field

The invention relates to the technical field of LED epitaxial design, in particular to an epitaxial growth method and structure of an LED structure containing a superlattice barrier layer.

Background technique

At present, when domestic MOCVD manufacturers grow LED epitaxial layers, the traditional structure includes N layer, light emitting layer, and P layer. The N layer uses SiH ₄ as the dopant, and the P layer uses Cp ₂ Mg as the dopant. The light emitting layer is made of Composed of InGaN/GaN superlattice materials, the impedances of these three parts are: R _{light-emitting layer} >R _{P layer} >R _{N layer} . Since the InGaN and GaN materials of the light-emitting layer do not add dopants, and the total thickness is generally 200-300nm, the resistance of this layer is higher than that of the doped N and P layers.

The LED device is driven by cross-current, and the negative effect brought by the high impedance of the light-emitting layer is the increase of the LED driving voltage. If the light-emitting layer is changed to N-type or P-type, the impedance of the light-emitting layer can be reduced, but it will affect the recombination efficiency of electrons and holes in the light-emitting layer, and the high doping concentration of the light-emitting layer will cause the device to fail to work. In order to reduce the impedance of the light-emitting layer, the traditional method is to reduce the thickness of the light-emitting layer, but the luminous efficiency of the device is lost; or a part of the light-emitting layer is doped with Si or Mg to reduce the impedance. The negative effect is the recombination of electrons and holes. low efficiency.

Contents of the invention

The purpose of the present invention is to provide an LED structure epitaxial growth method and its structure containing a superlattice barrier layer, so as to solve the technical problem of high impedance of the light-emitting layer.

In order to achieve the above object, a method for epitaxial growth of an LED structure containing a superlattice barrier layer provided by the present invention sequentially includes processing the substrate, growing a low-temperature buffer GaN layer, growing an undoped GaN layer, growing a Si-doped GaN layer, The steps of growing the light-emitting layer MQW, growing the P-type AlGaN layer, and growing the P-type GaN layer,

The steps of growing the light-emitting layer MQW layer are:

In a reaction chamber with a temperature of 750-850°C and a pressure of 200mbar to 400mbar, H ₂ and/or N ₂ are used as carrier gas, and In ions, NH ₃ and Ga ions are introduced to grow In-doped 3-3.5nm thick In _x Ga _(1-x) N layer, wherein x=0.15-0.25, In doping concentration 2E+20-3E+20/cm ³ ,

Among them, the steps of growing GaN: Si/GaN superlattice barrier layer are:

Stop feeding In ions, raise the temperature to 800-850°C, feed SiH ₄ , grow GaN: Si layer on the In _x Ga _(1-x) N layer in the reaction chamber, stop feeding SiH ₄ , GaN: Si in the reaction chamber GaN layer is grown on the layer;

Repeatedly feed SiH ₄ and stop feeding SiH ₄ , the GaN layer and GaN: Si layer are interlaced to form a GaN: Si/GaN superlattice barrier layer; the time ratio of SiH ₄ feeding and stopping feeding is 6:1- 1:6, Si doping concentration 1E+17-6E+17/cm ³ , GaN: Si/GaN superlattice barrier layer period number is 1-7;

In _x Ga _(1-x) N/(GaN: Si/GaN) period number is 14-15.

Preferably, the steps of growing a low-temperature buffer GaN layer, growing an undoped GaN layer, and growing a Si-doped GaN layer are:

Growth of low-temperature buffer GaN layer: grow a low-temperature buffer GaN layer with a thickness of 30-40nm on the substrate in a reaction chamber at 600-650°C;

Growth of undoped GaN layer: raise the temperature to 1100-1200°C, and continue to grow an undoped GaN layer with a thickness of 2-3um;

Growth of Si-doped GaN layer: Continuous growth of Si-doped N-type GaN, the doping concentration of Si is 9E+18-1E+19/cm ³ , and the total thickness is controlled at 2-3μm.

Preferably, the steps of growing a P-type AlGaN layer and growing a P-type GaN layer are:

Growth of P-type AlGaN layer: Continuously grow a P-type AlGaN layer with a thickness of 30-40nm in a reaction chamber at 930-980°C. The doping concentration of Al is 2E+20-3E+20/cm ³ , and the doping concentration of Mg 5E+19-6E+19 pieces/cm ³ ;

Growth of P-type GaN layer: raise the temperature to 930-950°C and continue to grow a magnesium-doped P-type GaN layer with a thickness of 100-150nm, and the doping concentration of Mg is 1E+19-1E+20/cm ³ .

The present invention also provides an LED epitaxial structure containing a superlattice barrier layer, including an In _x Ga _(1-x) N layer and a GaN:Si/GaN superlattice barrier layer in the light-emitting layer MQW:

Each GaN:Si/GaN superlattice barrier layer contains 1-7 double-layer combination units, each combination unit contains a GaN:Si layer and a GaN layer, and the thickness ratio of GaN:Si layer and GaN layer is 6 :1-1:6, the doping concentration of Si is 1E+17-6E+17 pieces/cm ³ ;

In the first GaN:Si/GaN superlattice barrier double-layer combination unit, the GaN layer is on top of the GaN:Si layer;

The period number of In _x Ga _(1-x) N/(GaN:Si/GaN) is 14-15.

Preferably, the thickness of the InGaN layer in the light-emitting layer MQW is 2.5-3 nm, and the thickness of the GaN:Si/GaN superlattice barrier layer is 11-13 nm.

Preferably, below the light-emitting layer MQW layer, from bottom to top include:

Substrate;

Low temperature buffer GaN layer: thickness is 30-40nm;

Undoped GaN layer: thickness is 2-3um;

Si-doped GaN layer: the doping concentration of Si is 9E+18-1E+19/cm ³ , and the total thickness is controlled at 2-3 μm.

Preferably, on the light-emitting layer MQW layer, from bottom to top include:

P-type AlGaN layer: thickness is 30-40nm, Al doping concentration is 2E+20-3E+20 pieces/cm ³ , Mg doping concentration is 5E+19-6E+19 pieces/cm ³ ;

P-type GaN layer: the thickness is 100-150 nm, and the doping concentration of Mg is 1E+19-1E+20 pieces/cm ³ .

Preferably, in each of the double-layer combined units: the GaN:Si layer is under the GaN layer.

The present invention has the following beneficial effects:

In the present invention, the original non-doped Si-doped GaN barrier layer is replaced by a GaN/GaN:Si superlattice layer, and the resistance of the light-emitting layer is reduced, so that the driving voltage of the device is reduced, but at the same time, the leakage of the device is not affected and luminous intensity.

GaN/GaN: The advantage of Si interlaced double-layer structure superlattice layer is that some layers contain Si and some layers do not contain Si, which avoids the problem of device leakage caused by the entire barrier being doped with Si, and also avoids the excessive resistance of the light-emitting layer. The disadvantage of high impact device drive voltage.

In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. Hereinafter, the present invention will be described in further detail with reference to the drawings.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the attached picture:

FIG. 1 is a schematic diagram of an existing LED epitaxial structure;

Fig. 2 is a schematic diagram of the LED epitaxial structure of a preferred embodiment of the present invention;

3 is a schematic diagram of the energy band structure of an existing light-emitting layer and an electron blocking layer;

Fig. 4 is a schematic diagram of the energy band structure of the light-emitting layer and the electron blocking layer of the preferred embodiment of the present invention;

Fig. 5 is a schematic diagram of chip luminance comparison between the preferred embodiment of the present invention and the comparative embodiment;

Fig. 6 is a schematic diagram of a comparison of chip leakage conditions between the preferred embodiment of the present invention and the comparative embodiment;

Fig. 7 is a schematic diagram of the driving voltage comparison between the preferred embodiment of the present invention and the comparative embodiment;

Among them, 1. substrate, 2. low-temperature buffer GaN layer, 3. undoped GaN layer, 4. Si-doped GaN layer, 5. light-emitting layer MQW layer, 6. In _x Ga _(1-x) N layer; 7. GaN: Si/GaN superlattice barrier layer, 8. P-type AlGaN layer, 9. P-type GaN layer.

detailed description

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in various ways defined and covered by the claims.

Referring to Fig. 2, the present invention provides a method for epitaxial growth of an LED structure containing a superlattice barrier layer, which sequentially includes processing the substrate, growing a low-temperature buffer GaN layer, growing an undoped GaN layer, growing a Si-doped GaN layer, The steps of growing the light-emitting layer MQW, growing the P-type AlGaN layer, and growing the P-type GaN layer,

The steps of growing the light-emitting layer MQW layer are:

In a reaction chamber with a temperature of 750-850°C and a pressure of 200mbar to 400mbar, H ₂ and/or N ₂ are used as carrier gas, and In ions, NH ₃ and Ga ions are introduced to grow In-doped 3-3.5nm thick In _x Ga _(1-x) N layer, wherein x=0.15-0.25, In doping concentration 2E+20-3E+20/cm ³ ,

Among them, the steps of growing GaN: Si/GaN superlattice barrier layer are:

Stop feeding In ions, raise the temperature to 800-850°C, feed SiH ₄ , grow GaN: Si layer on the In _x Ga _(1-x) N layer in the reaction chamber, stop feeding SiH ₄ , GaN: Si in the reaction chamber GaN layer is grown on the layer.

Repeatedly feed SiH ₄ and stop feeding SiH ₄ , the GaN layer and GaN: Si layer are interlaced to form a GaN: Si/GaN superlattice barrier layer; the time ratio of SiH ₄ feeding and stopping feeding is 6:1- 1:6, Si doping concentration 1E+17-6E+17/cm ³ , GaN: Si/GaN superlattice barrier layer period number is 1-7;

In _x Ga _(1-x) N/(GaN: Si/GaN) period number is 14-15.

In the present invention, GaN/GaN: Si superlattice layer is used to replace the traditional non-doped Si light-emitting layer GaN barrier layer, which reduces the resistance of the light-emitting layer and reduces the driving voltage of the device, but at the same time does not affect the leakage of the device and luminous intensity.

The following describes the comparative example 1 of sample 1 prepared by the existing traditional method, and the example 1 of sample 2 prepared by the growth method of the present invention, and then compares the performance of sample 1 and sample 2 obtained by the two methods.

Comparative example one,

1. Treat the sapphire substrate at high temperature for 5-6 minutes in a hydrogen atmosphere at 1100-1200°C;

2. Lower the temperature to 600-650°C, and grow a low-temperature buffer layer GaN with a thickness of 30-40nm on the sapphire substrate;

3. Raise the temperature to 1100-1200℃, and continue to grow 2-3um undoped GaN;

4. Then continue to grow N-type GaN doped with Si, the doping concentration of Si is 9E+18-1E+19/cm ³ , and the total thickness is controlled at 2-3μm;

5. Periodically grow the light-emitting layer MQW, grow an In _x Ga _(1-x) N (x=0.15-0.25) layer with a thickness of 3-3.5nm doped with In at a low temperature of 700-750°C, and the doping concentration of In is 2E +20-3E+20 pieces/cm ³ , grow a GaN layer with a thickness of 10-14nm at a high temperature of 800-850°C, and the number of In _x Ga _(1-x) N/GaN cycles is 14-15;

6. Then increase the temperature to 950-1000°C and continue to grow a P-type AlGaN layer with a thickness of 30-40nm. The doping concentration of Al is 2E+20-3E+20/cm ³ , and the doping concentration of Mg is 5E+19 -6E+19 pcs/cm ³ ;

7. Then raise the temperature to 930-950°C and continue to grow a 100-150nm Mg-doped P-type GaN layer, and the Mg doping concentration is 1E+19-1E+20 pieces/cm ³ ;

8. Finally, lower the temperature to 700-750°C, keep it warm for 20-30 minutes, and then cool in the furnace to obtain sample 1.

The structure of sample 1 can be seen in Figure 1, and its energy band diagram is shown in Figure 3. Among them, the upper curve is the GaN conduction band energy level, the middle dotted line is the GaN Fermi level; the lower curve is the GaN valence band energy level, and points A and B represent the GaN layer and the InGaN layer respectively.

Embodiment one,

The invention uses VEECO MOCVD to grow high-brightness GaN-based LED epitaxial wafers. Use high-purity _H2 or high-purity _N2 or the mixed gas of high-purity _H2 and high-purity _N2 as carrier gas, high-purity _NH3 as N source, metal-organic source trimethylgallium (TMGa), triethylgallium (TEGa) as gallium source, trimethylindium (TMIn) as indium source, N-type dopant as silane (SiH ₄ ), trimethylaluminum (TMAl) as aluminum source, and P-type dopant as magnesocene (CP ₂ Mg), the substrate is (0001) sapphire, and the reaction pressure is between 100mbar and 800mbar. The specific growth method is as follows (please refer to Figure 2 for the epitaxial structure, and Figure 4 for the energy band in step 5):

1. Treat the sapphire substrate at high temperature for 5-6 minutes in a hydrogen atmosphere at 1100-1200°C;

2. Lower the temperature to 600-650°C, and grow a low-temperature buffer layer GaN with a thickness of 30-40nm on the sapphire substrate;

3. Raise the temperature to 1100-1200℃, and continue to grow 2-3um undoped GaN;

4. Then continue to grow N-type GaN doped with Si, the doping concentration of Si is 9E+18-1E+19/cm ³ , and the total thickness is controlled at 2-3μm;

5. Periodically grow the light-emitting layer MQW, grow an In _x Ga _(1-x) N (x=0.15-0.25) layer with a thickness of 3-3.5nm doped with In at a low temperature of 700-750°C, and the doping concentration of In is 2E +20-3E+20 pieces/cm ³ ;

Grow GaN with a thickness of 10-14nm at a high temperature of 800-850°C: Si/GaN superlattice layer: Stop feeding In ions, raise the temperature to 800-850°C, feed SiH ₄ , In _x Ga _{(1-x )} grow a GaN:Si layer on the N layer, stop feeding SiH ₄ , and grow a GaN layer on the GaN:Si layer in the reaction chamber.

Repeatedly feed SiH ₄ and stop feeding SiH ₄ , the GaN layer and GaN: Si layer are interlaced to form a GaN: Si/GaN superlattice barrier layer; the time ratio of SiH ₄ feeding and stopping feeding is 6:1- 1:6, the thickness ratio of the grown GaN:Si layer to GaN layer is 6:1-1:6, the doping concentration of Si is 1E+17-6E+17/cm ³ , and the GaN:Si/GaN super The period number of the lattice barrier layer is 1-7;

The period number of In _x Ga _(1-x) N/(GaN: Si/GaN) is 14-15;

6. Then raise the temperature to 950-1000°C and continue to grow a P-type AlGaN layer of 30-40nm, the doping concentration of Al is

2E+20-3E+20 pieces/cm ³ , the doping concentration of Mg is 5E+19-6E+19 pieces/cm ³ ;

7. Then raise the temperature to 930-950°C and continue to grow a 100-150nm Mg-doped P-type GaN layer, and the Mg doping concentration is 1E+19-1E+20 pieces/cm ³ ;

8. Finally, lower the temperature to 700-750°C, keep it warm for 20-30 minutes, and then cool in the furnace; sample 2 is obtained.

The structure of sample 2 can be seen in Figure 2, and its energy band diagram is shown in Figure 4. Among them, the upper curve is the GaN conduction band energy level, the middle dotted line is the GaN Fermi energy level; the lower curve is the GaN valence band energy level, D, E, and F points represent the GaN layer, InGaN layer, GaN:Si layer respectively; the GaN layer . The GaN:Si layer is a double-layer composite structure of the light-emitting layer GaN/GaN:Si superlattice layer.

Referring to the method of Example 1, continue to generate sample 3 and sample 4, and the differences in process conditions are shown in Table 1 to Table 3 below.

Table 1 Comparison of growth parameters between sample 1 and sample 2

Table 2 Comparison of growth parameters between sample 1 and sample 3

Table 3 Comparison of growth parameters

Sample 1 and samples 2, 3, and 4 were plated with an ITO layer of about 150nm under the same pre-process conditions, with a Cr/Pt/Au electrode of about 200nm under the same conditions, and with a protective layer of SiO ₂ about 50nm under the same conditions, and then in Under the same conditions, the sample was ground and cut into chip particles of 762μm*762μm (30mi*30mil), and then 150 grains of each of sample 1 and sample 2, 3, and 4 were selected at the same position, and packaged into White LEDs. Then the photoelectric properties of sample 1 and samples 2, 3, and 4 were tested using an integrating sphere under the condition of a driving current of 350 mA.

Referring to attached drawing 5, samples 2, 3, and 4 are not significantly improved compared with sample 1; referring to attached drawing 6, the leakage conditions of samples 2, 3, and 4 have little change compared with sample 1; referring to attached drawing 7, samples 2, The driving voltage of 3 and 4 is about 0.15-0.2v lower than that of sample 1, and the effect is outstanding.

The present invention also provides an LED epitaxial structure containing a superlattice barrier layer, referring to FIG. 2 , including an In _x Ga _(1-x) N layer 6 and a GaN:Si/GaN supercrystal in the light-emitting layer MQW layer 5 Lattice barrier layer 7:

Each GaN: Si/GaN superlattice barrier layer 7 contains 1-7 double-layer combination units, each combination unit comprises a GaN: Si layer and a GaN layer, and the thickness ratio of GaN: Si layer and GaN layer is 6:1-1:6, Si doping concentration 1E+17-6E+17/cm ³ ,

In the first GaN:Si/GaN superlattice barrier layer 7 double-layer combination unit, the GaN layer is located on top of the GaN:Si layer.

The period number of In _x Ga _(1-x) N/(GaN:Si/GaN) is 14-15.

Preferably, the thickness of the InGaN layer in the light-emitting layer MQW may be 2.5-3 nm, and the thickness of the GaN:Si/GaN superlattice barrier layer 7 is 11-13 nm.

Preferably, below the light-emitting layer MQW layer 5, it includes from bottom to top:

substrate1;

Low temperature buffer GaN layer 2: the thickness is 30-40nm;

Undoped GaN layer 3: the thickness is 2-3um;

Si-doped GaN layer 4: the doping concentration of Si is 9E+18-1E+19/cm ³ , and the total thickness is controlled at 2-3 μm.

Preferably, on the light-emitting layer MQW layer 5, from bottom to top include:

P-type AlGaN layer 8: the thickness is 30-40nm, the doping concentration of Al is 2E+20-3E+20 pieces/cm ³ , the doping concentration of Mg is 5E+19-6E+19 pieces/cm ³ ;

P-type GaN layer 9: the thickness is 100-150 nm, and the doping concentration of Mg is 1E+19-1E+20 pieces/cm ³ .

Preferably, in each of the double-layer combined units: the GaN:Si layer is under the GaN layer.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. the LED structure epitaxial growth method containing superlattices barrier layer, includes processing substrate, low temperature growth buffer successively GaN layer, growth undope GaN layer, growth mix Si GaN layer, growth luminescent layer MQW, growing P-type AlGaN layer, Growth P-type GaN layer step, it is characterised in that

Described luminescent layer MQW includes In_xGa_(1-x)N shell and GaN:Si/GaN superlattices barrier layer, grow luminescent layer MQW The step of layer is:

It is 750-850 DEG C in temperature, in the reative cell of 200mbar to 400mbar pressure, uses H₂And/or N₂As carrier gas, It is passed through In ion, NH₃With Ga ion, the In of the 3-3.5nm thickness of growth doping In_xGa_(1-x)N shell, wherein x=0.15-0.25, In doping content 2E20-3E20/cm³,

Wherein, the step of growth GaN:Si/GaN superlattices barrier layer is:

Stopping being passed through In ion, liter high-temperature, to 800-850 DEG C, is passed through SiH₄, In in reative cell_xGa_(1-x)Grow on N shell GaN:Si layer, stops being passed through SiH₄, in reative cell, on GaN:Si layer, grow GaN layer；

Repeatedly it is passed through SiH₄It is passed through SiH with stopping₄, GaN layer and GaN:Si layer interlaced formation GaN:Si/GaN are super brilliant Lattice barrier layer；SiH₄It is passed through and stops doping content 1E17-6E17 that time scale is 6:1-1:6, the Si/cm being passed through³, GaN: The periodicity of Si/GaN superlattices barrier layer is 1-7；

In_xGa_(1-x)N/ (GaN:Si/GaN) periodicity is 14-15.

A kind of LED structure epitaxial growth method containing superlattices barrier layer the most according to claim 1, it is characterised in that Described low temperature growth buffer GaN layer, the growth step of GaN layer that GaN layer, growth mix Si that undopes is:

Low temperature growth buffer GaN layer: in the reative cell of 600-650 DEG C, is the low temperature of 30-40nm at Grown thickness Buffer gan layer；

Grow the GaN layer that undopes: increasing the temperature to 1100-1200 DEG C, continued propagation thickness is the GaN layer that undopes of 2-3um；

The GaN layer of Si is mixed in growth: N-type GaN of continued propagation doping Si, the doping content of Si is 9E18-1E19/cm³, Gross thickness controls in 2-3 μm.

A kind of LED structure epitaxial growth method containing superlattices barrier layer the most according to claim 1, it is characterised in that Growing P-type AlGaN layer, the step of growth P-type GaN layer be:

Growing P-type AlGaN layer: continued propagation thickness is the p-type AlGaN layer of 30-40nm in the reative cell of 930-980 DEG C, The doping content of Al is 2E20-3E20/cm³, the doping content of Mg is 5E19-6E19/cm³；

Growth P-type GaN layer: increase the temperature to p-type GaN mixing magnesium that 930-950 DEG C of continued propagation thickness is 100-150nm Layer, the doping content of Mg is 1E19-1E20/cm³。

4. the LED epitaxial structure containing superlattices barrier layer, it is characterised in that include In at luminescent layer MQW_xGa_(1-x)N shell and GaN:Si/GaN superlattices barrier layer:

Each GaN:Si/GaN superlattices barrier layer comprises 1-7 bilayer combination unit, and each assembled unit comprises a GaN: Si layer and a GaN layer, the thickness proportion of GaN:Si layer and GaN layer is doping content 1E17-6E17 of 6:1-1:6, Si Individual/cm³；

In the bilayer combination unit of first GaN:Si/GaN superlattices barrier layer, GaN layer is positioned on GaN:Si layer；

In_xGa_(1-x)The periodicity of N/ (GaN:Si/GaN) is 14-15.

A kind of LED epitaxial structure containing superlattices barrier layer the most according to claim 4, it is characterised in that luminescent layer InGaN layer thickness in MQW be the thickness of 2.5-3nm, GaN:Si/GaN superlattices barrier layer be 11-13nm.

A kind of LED epitaxial structure containing superlattices barrier layer the most according to claim 4, it is characterised in that in luminescence Under layer mqw layer, include the most successively:

Substrate；

Low temperature buffer GaN layer: thickness is 30-40nm；

Undope GaN layer: thickness is 2-3um；

The doping content mixing the GaN layer of Si: Si is 9E18-1E19/cm³, gross thickness controls in 2-3 μm.

A kind of LED epitaxial structure containing superlattices barrier layer the most according to claim 5, it is characterised in that in luminescence On layer mqw layer, include the most successively:

P-type AlGaN layer: thickness be the doping content of 30-40nm, Al be 2E20-3E20/cm³, the doping content of Mg 5E19-6E19/cm³；

P-type GaN layer: thickness be the doping content of 100-150nm, Mg be 1E19-1E20/cm³。

A kind of LED epitaxial structure containing superlattices barrier layer the most according to claim 5, it is characterised in that each In described bilayer combination unit: GaN:Si layer is under GaN layer.