CN218069880U - Novel insertion layer and LED (light emitting diode) epitaxial wafer comprising same - Google Patents

Abstract

A novel insertion layer comprises a high-temperature uGaN layer and a superlattice Mg doping layer which are sequentially grown on the surface of a multi-quantum well layer, wherein the high-temperature uGaN layer is grown on the surface of the multi-quantum well layer, and the superlattice Mg doping layer is grown on the surface of the high-temperature uGaN layer; the superlattice Mg doped layer is a superlattice structure consisting of alternately stacked MgGaN layers and MgN layers. The utility model discloses constitute by high temperature growth uGaN and superlattice MgGaN and MgN, can effectively improve the crystal quality, still can improve hole concentration simultaneously, increase electron hole recombination rate to promote Led's luminous efficacy.

Description

Novel insertion layer and LED (light emitting diode) epitaxial wafer comprising same

Technical Field

The utility model relates to a semiconductor lighting technology field, concretely relates to novel insertion layer and contain LED emitting diode epitaxial wafer on this insertion layer.

Background

The gallium nitride-based Light Emitting Diode (LED) has the advantages of high photoelectric efficiency conversion, small volume, long service life and the like, is widely applied to solid-state illumination and backlight sources, leads the third-generation illumination technical revolution, and obtains great economic benefit.

A multi-quantum well (MQWs) structure in a GaN-based LED is the core for realizing electric-optical conversion, the crystal quality of the MQWs structure directly determines the photoelectric performance of the LED, and V-shaped pit defects are common defects in the GaN-based material, which can increase the stress borne by the material and have influence on the crystal quality of the GaN material. The formation of V-shaped pits and the method of filling the cap have also attracted considerable attention.

As shown in fig. 1, the current GaN-based led chip structure is: the sapphire patterned substrate comprises a sapphire patterned substrate 1, an AlN/AlGaN buffer layer 2, a non-doped GaN layer 3, a doped n-type GaN layer 4, a multi-quantum well layer and a Mg-doped p-type GaN layer; wherein the multiple quantum well layer includes: a first barrier layer 5, a high temperature multiple quantum well layer 6 and a low temperature multiple quantum well layer 7 and a final barrier layer 10. The mainstream of the Vpits filling method is to use high-temperature and low-temperature multi-quantum well growth to cover, so that the electron hole recombination rate is low, and the light emitting effect is influenced.

In addition, vpits are generated during the growth of the high temperature multiple quantum well layer, and extend after the growth of the high temperature multiple quantum well layer, therefore, the filling manner and degree of Vpits are different, which affects the crystal quality, and thus affects the ESD and light emitting efficiency.

SUMMERY OF THE UTILITY MODEL

Aiming at the technical problems, the technical scheme provides a novel insertion layer and an LED epitaxial wafer comprising the same, and the novel insertion layer is composed of high-temperature-grown uGaN, superlattice MgGaN and MgN, so that the crystallization quality can be effectively improved, the hole concentration can be improved, the electron hole recombination rate can be increased, and the LED light efficiency can be improved; the problems can be effectively solved.

The utility model discloses a following technical scheme realizes:

a novel insertion layer comprises a high-temperature uGaN layer and a superlattice Mg doping layer which are sequentially grown on the surface of a multi-quantum well layer, wherein the high-temperature uGaN layer is grown on the surface of the multi-quantum well layer, and the superlattice Mg doping layer is grown on the surface of the high-temperature uGaN layer; the superlattice Mg doped layer is a superlattice structure consisting of alternately stacked MgGaN layers and MgN layers.

Furthermore, the concentration of Mg impurities in the superlattice Mg doped layer is 1E18-3E18.

An LED epitaxial wafer containing a novel insertion layer comprises the novel insertion layer.

Furthermore, the LED light-emitting diode epitaxial wafer comprises a substrate, and an N-type semiconductor layer, a multi-quantum well layer, a novel insertion layer and a P-type semiconductor layer which are sequentially stacked on the surface of the substrate.

Furthermore, the LED epitaxial wafer comprises a substrate, an AlN evaporation layer, a buffer layer, a non-doped GaN layer, a doped nGaN layer, a first barrier layer, a high-temperature multi-quantum well layer, a low-temperature multi-quantum well layer, a novel insertion layer and a Mg-doped p-type GaN layer which are sequentially stacked on the surface of the substrate.

Further, the doped nGaN layer is a heavily Si-doped n-type GaN layer, and the first barrier layer is a lightly Si-doped LT-GaN layer.

Further, the multiple quantum well layer comprises a plurality of barrier layers and well layers which are alternately stacked, and the insertion layer is directly arranged on the last well layer of the multiple quantum well layer.

Furthermore, the substrate is a sapphire substrate with a PSS micro-pattern on the surface.

Furthermore, the thickness of the novel insertion layer is 100-300 nm.

Further, the thickness of the high-temperature uGaN layer is 10-100 nm, the MgGaN layer and the MgN layer in the superlattice Mg doped layer are alternately laminated for 2-10 times, the thickness of each MgGaN layer is 10-50 nm, and the thickness of each MgN layer is 10-50 nm.

Advantageous effects

The utility model provides a novel insertion layer and contain LED epitaxial wafer on this insertion layer compares with prior art, and it has following beneficial effect:

(1) The novel insertion layer in the technical scheme is as follows: after the growth of the low-temperature multi-quantum well layer is finished, firstly growing a uGaN layer in a high-temperature environment for 30 s-1 min, wherein the thickness needs to be controlled within 100nm because InGaN is influenced to a certain extent at high temperature; secondly, growing the superlattice MgGaN/MgN, and because only MgN crystal grows and the quality is poor, adopting a superlattice growth mode to carry out mg-doped epitaxial growth; the structural design can reduce the defects of extending of the Vpits, improve the flatness of the Vpits, improve the crystallization quality and improve the ESD capability; in addition, the distance between the quantum well and the MQW layer is reduced, hole concentration is improved, and interaction of carriers among wells is increased, so that the luminous efficiency of the LED is improved.

(2) According to the technical scheme, the LED light effect is improved by the aid of the low-temperature multi-quantum well layer (namely, the low-temperature MQW)/HTQW (namely, the high-temperature MQW layer) and the novel insertion layer, wherein the insertion layer is composed of high-temperature growth uGaN, superlattice MgGaN and MgN, crystallization quality can be effectively improved, hole concentration can be improved, and electron hole recombination rate is increased.

Drawings

FIG. 1 is a schematic diagram of a conventional LED device structure.

Fig. 2 is a schematic structural diagram of the novel insert layer of the present invention.

Fig. 3 is a schematic structural diagram of an LED device in the present invention.

Fig. 4 is a structural comparison diagram of the LED device of the present invention and the original LED device.

The labels in the figures are: the multilayer film comprises a 1-AlN layer, a 2-buffer layer, a 3-undoped uGaN layer, a 4-doped nGaN layer, a 5-first barrier layer, a 6-high-temperature multi-quantum well layer, a 7-low-temperature multi-quantum well layer, an 8-novel insertion layer, an 81-high-temperature uGaN layer, a 82-superlattice Mg doping layer, an 821-MgGaN layer, a 822-MgN layer, a 9-p type GaN layer and a 10-MQW cap layer.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. The described embodiments are only some, but not all embodiments of the invention. Under the prerequisite that does not deviate from the design concept of the utility model, the ordinary person in the art should fall into the protection scope of the utility model to the various changes and improvements that the technical scheme of the utility model made.

Example 1:

as shown in fig. 2, a novel insertion layer comprises a high-temperature uGaN layer 81 and a superlattice Mg doping layer 82 which are sequentially grown on the surface of a multiple quantum well layer, wherein the high-temperature uGaN layer 81 is grown on the surface of the multiple quantum well layer, and the superlattice Mg doping layer 82 is grown on the surface of the high-temperature uGaN layer 81; the superlattice Mg doped layer 82 has a superlattice structure composed of alternately stacked MgGaN layers 821 and MgN layers 822.

The total thickness of the novel insertion layer 8 is 100-300 nm, wherein the thickness of the high-temperature uGaN layer 81 is 10-100 nm, the MgGaN layers 821 and the MgN layers 822 in the superlattice Mg doping layer 82 are alternately laminated for 2-10 times, the thickness of each MgGaN layer 821 is 10-50 nm, and the thickness of each MgN layer 822 is 10-50 nm.

Example 2:

an LED epitaxial wafer containing the novel insertion layer comprises the novel insertion layer.

The LED epitaxial wafer comprises a substrate, and an N-type semiconductor layer, a multi-quantum well layer, a novel insertion layer and a P-type semiconductor layer which are sequentially stacked on the surface of the substrate.

The LED epitaxial wafer has the following specific structure: the substrate is a sapphire substrate with a PSS micro-pattern on the surface. The GaN-based light-emitting diode comprises an AlN evaporation layer 1, a buffer layer 2, a non-doped GaN layer 3, an Si-doped n-type GaN layer 4, a first barrier layer 5 (namely an intermediate-temperature buffer layer between a bottom layer and an MQW), a high-temperature multi-quantum well layer 6 (namely a high-temperature MQW layer), a low-temperature multi-quantum well layer 7 (namely a light-emitting well layer), a novel insertion layer 8 and an Mg-doped p-type GaN layer 9 which are sequentially arranged on a substrate from bottom to top. As shown in fig. 3.

The nGaN doped layer 4 is a heavily Si-doped n-type GaN layer, and the first barrier layer is a lightly Si-doped LT-GaN layer. The thickness of the novel insertion layer 8 is greater than that of the P-type semiconductor layer. As shown in fig. 4.

The growth method of the novel insertion layer 8 comprises the following specific operation steps:

step 1: evaporating and plating a sapphire substrate with a PSS micro-pattern on the surface in a PVD (physical vapor deposition) mode to obtain an AlN layer as a base; and placing the sapphire substrate in a physical vapor deposition reaction chamber, and growing an AlN layer with the thickness of 25nm to form the base.

Step 2: the buffer layer with a thickness of 20nm was grown under a pressure of 300torr and a temperature of 600 ℃.

And step 3: growing a non-doped GaN layer with the thickness of 3.5-4 um on the grown buffer layer under the conditions of high temperature and low pressure (the temperature is controlled at 1100 ℃ and the pressure is 600 torr).

And 4, step 4: doping the nGaN layer, introducing Si concentration 2E19 under the conditions of high temperature and low pressure (constant temperature 1100 ℃ and controlled pressure of 100 torr), and carrying out epitaxial growth for about 20-30 min to obtain the doped nGaN layer with the thickness of 1.5-2 um.

And 5: controlling the temperature at 800-900 deg.c and the pressure at 300torr, and doping Si 2E18 to obtain the first barrier layer with thickness of 200-500 nm.

Step 6: growing a high-temperature multi-quantum well layer with the thickness of about 0.05um for 3-5 periods; wherein the temperature is controlled to be 850 ℃, and the high-temperature barrier layer grown under the pressure of 300torr is about 8nm; the temperature was adjusted to 780 ℃ and the high temperature well layer was grown to about 2nm.

And 7: then 8-12 periods of low temperature multiple quantum wells are grown again at low temperature, and the thickness of the multiple quantum wells is about 0.01um. Controlling the pressure to be 300torr, and growing a low-temperature barrier layer with the thickness of 8nm at the temperature of 830 ℃; the temperature was adjusted to 780 ℃ and a low temperature well layer was grown to a thickness of 2nm.

And 8: growing a novel insertion layer: the growth method of the novel insertion layer comprises the following steps: under the environment of high temperature 880-950 ℃, firstly growing a UGaN layer, and then repeatedly growing MgGaN/MgN superlattice.

The growth method of the novel insertion layer specifically comprises the following steps:

the first step is as follows: after the low-temperature multi-quantum well layer grows, controlling the temperature to be 880-930 ℃ and the pressure to be 300mbar, and growing a first sub-layer of the uGaN layer;

the second step is that: carrying out superlattice growth on a MgGaN/MgN second sublayer at the constant temperature of 880-930 ℃ and under the pressure of 300 mbar; the parameters of the growth thickness and the Mg concentration of the MgGaN/MgN second sublayer are as follows:

a. growing MgGaN, wherein the concentration of Mg is 1E18 to 3E18, the growth time is 10s, and the thickness is about 50-200 nm;

b. growing MgN, wherein the concentration of Mg is 1E18 to 3E18, the growth time is 5s, and the thickness is about 10 to 100nm;

c. repeatedly growing n periods of MgGaN layer and MgN layer, n >1.

And step 9: growing the LTP/PGaN layer: TMGa is introduced, the temperature is controlled at 950 ℃, the pressure is controlled at 200torr, and a PGaN layer with the thickness of 0.2um is grown in the mixed atmosphere of nitrogen and hydrogen.

The inventor tests the LED epitaxial wafer structure obtained by the method of the invention and the original LED epitaxial wafer structure, and the test results are shown in Table 1:

TABLE 1

The data in table 1 show that the value obtained by the AFM flatness test of the LED epitaxial wafer structure obtained by the present scheme is smaller than that of the original structure, that is, the flatness of the LED epitaxial wafer structure obtained by the present scheme is better.

After the new structure and the original structure are simultaneously produced into products of the same model, the brightness value of the products of the LED epitaxial wafer structure obtained by the scheme is larger than that of the original structure, and the luminous efficiency of the LED is improved. Meanwhile, the energizing voltage value of the product of the LED epitaxial wafer structure obtained by the scheme is smaller than that of the original structure, so that the product produced by the method is more electricity-saving.

Claims (8)

1. A novel interposer, comprising: the high-temperature uGaN layer and the superlattice Mg doped layer (82) sequentially grow on the surface of the multi-quantum well layer, the high-temperature uGaN layer (81) grows on the surface of the multi-quantum well layer, and the superlattice Mg doped layer (82) grows on the surface of the high-temperature uGaN layer (81); the superlattice Mg doped layer (82) is of a superlattice structure consisting of MgGaN layers (821) and MgN layers (822) which are alternately stacked.

2. An LED light-emitting diode epitaxial wafer containing a novel insertion layer is characterized in that: comprising the novel insertion layer (8) of claim 1.

3. The LED light-emitting diode epitaxial wafer comprising the novel insertion layer as claimed in claim 2, wherein: the LED epitaxial wafer comprises a substrate, and an N-type semiconductor layer, a multi-quantum well layer, a novel insertion layer (8) and a P-type semiconductor layer which are sequentially stacked on the surface of the substrate.

4. The LED light-emitting diode epitaxial wafer comprising the novel insertion layer as claimed in claim 2, wherein: the LED light-emitting diode epitaxial wafer comprises a substrate, an AlN vapor deposition layer (1), a buffer layer (2), an undoped GaN layer (3), a doped nGaN layer (4), a first barrier layer (5), a high-temperature multi-quantum well layer (6), a low-temperature multi-quantum well layer (7), a novel insertion layer (8) and a Mg-doped p-type GaN layer (9), wherein the AlN vapor deposition layer, the buffer layer, the first barrier layer, the high-temperature multi-quantum well layer, the low-temperature multi-quantum well layer and the Mg-doped p-type GaN layer are sequentially stacked on the surface of the substrate.

5. The LED light-emitting diode epitaxial wafer comprising the novel insertion layer as claimed in claim 3, wherein: the multiple quantum well layer comprises a plurality of barrier layers and potential well layers which are alternately stacked, and the insertion layer is directly arranged on the last potential well layer of the multiple quantum well layer.

6. An LED light-emitting diode epitaxial wafer comprising a novel insertion layer according to any one of claims 3 to 5, wherein: the substrate is a sapphire substrate with a PSS micro-pattern on the surface.

7. The LED light-emitting diode epitaxial wafer comprising the novel insertion layer as claimed in claim 6, wherein: the thickness of the novel insertion layer (8) is 100-300 nm.

8. The LED light-emitting diode epitaxial wafer comprising the novel insertion layer as claimed in claim 6, wherein: the thickness of the high-temperature uGaN layer (81) is 10-100 nm, the MgGaN layers (821) and the MgN layers (822) in the superlattice Mg doped layer (82) are alternately laminated for 2-10 times, the thickness of each MgGaN layer (821) is 10-50 nm, and the thickness of each MgN layer (822) is 10-50 nm.

Images