An ultraviolet light-emitting diode epitaxial structure, an ultraviolet light-emitting diode, and an electronic device

Abstract

An embodiment of the present invention provides an ultraviolet light-emitting diode epitaxial structure, an ultraviolet light-emitting diode, and an electronic device. The epitaxial structure includes a substrate, a first AlN layer, a multi-period composite regulation layer, an n-type Al x Ga 1‑x N contact layer, a multi-quantum well light-emitting layer, a p-type Al y Ga 1‑y N blocking layer, and a p-type GaN layer, which are grown in sequence from bottom to top. The multi-period composite regulation layer includes multiple periodic structures grown in sequence from bottom to top. Each periodic structure includes a second AlN layer, an Al m Ga 1‑m N layer, an Al n Ga 1‑n N layer, and an Al k Ga 1‑k N layer. Among them, the Al components in the n-type Al x Ga 1‑x N contact layer, the Al m Ga 1‑m N layer, the Al n Ga 1‑n N layer, and the Al k Ga 1‑k N layer are different. By growing a multi-period composite regulation layer between the first AlN layer and the n-type Al x Ga 1‑x N contact layer, the present invention reduces the lattice mismatch between the first AlN layer and the n-type Al x Ga 1‑x N contact layer, regulates the warping of the ultraviolet light-emitting diode epitaxial wafer, filters the dislocations extending upward from the first AlN layer, reduces the compressive stress of the n-type Al x Ga 1‑x N contact layer, improves the crystal quality, and enhances the light-emitting efficiency of the device.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular, to an ultraviolet light-emitting diode epitaxial structure, an ultraviolet light-emitting diode, and an electronic device. Background Art

[0002] Compared with the traditional ultraviolet light source mercury lamp, the nitride material ultraviolet light-emitting diode has the advantages of low voltage, adjustable wavelength, environmental friendliness, etc. It has broad application prospects mainly in the fields of sterilization, medical treatment, biochemical detection, etc.

[0003] At present, the ultraviolet LED epitaxial growth technology is not yet mature, and there are still key scientific problems such as large mismatch, low quantum efficiency, low doping activation efficiency, and polarization control in the epitaxial structure growth. In the ultraviolet LED epitaxial structure, due to the lattice mismatch between the AlN layer and the n-type AlGaN contact layer, new dislocations will be generated at the interface between the AlN layer and the n-type AlGaN layer, and at the same time, a large compressive stress will be generated in the n-type AlGaN layer, resulting in a large warpage of the epitaxial wafer, which in turn affects the light-emitting efficiency, wavelength uniformity, and optoelectronic characteristic uniformity of the device. Summary of the Invention

[0004] In view of the above problems, the present invention provides an ultraviolet light-emitting diode epitaxial structure, an ultraviolet light-emitting diode, and an electronic device.

[0005] In a first aspect of an embodiment of the present invention, an ultraviolet light-emitting diode epitaxial structure is provided, including a substrate, a first AlN layer, a multi-period composite regulation layer, an n-type Al x Ga 1-x N contact layer, a multi-quantum well light-emitting layer, a p-type Al y Ga 1-y N barrier layer, and a p-type GaN layer, which are grown in sequence from bottom to top. The multi-period composite regulation layer includes a plurality of periodic structures grown in sequence from bottom to top, and each periodic structure includes a second AlN layer, an Al m Ga 1-m N layer, an Al n Ga 1-n N layer, and an Al k Ga 1-k N layer grown in sequence from bottom to top. Among them, the Al components in the n-type Al x Ga 1-x N contact layer, the Al m Ga 1-m N layer, the Al n Ga 1-n N layer, and the Al k Ga 1-k N layer are different.

[0006] Preferably, the n-type Alx Ga 1-x N contact layer, Al m Ga 1-m N layer, Al n Ga 1-n N layer and Al k Ga 1-k The Al component in the N layer is: 0 < n < x < k < m < 1.

[0007] Preferably, in the periodic structure, the thickness of the second AlN layer ≤ the thickness of the Al m Ga 1-m N layer < the thickness of the Al n Ga 1-n N layer < the thickness of the Al k Ga 1-k N layer.

[0008] Preferably, the number of the periodic structures is 2 to 100.

[0009] Preferably, the growth temperature of the multi-period composite regulation layer is 1000 °C to 1250 °C.

[0010] Preferably, the growth pressure of the multi-period composite regulation layer is 30 torr to 150 torr.

[0011] Preferably, in the n-type Al x Ga 1-x In the N contact layer, 0.4 ≤ x ≤ 1.

[0012] Preferably, in the p-type Al y Ga 1-y In the N blocking layer, 0.5 ≤ y ≤ 1.

[0013] In the second aspect of the embodiments of the present invention, an ultraviolet light-emitting diode is provided, and the ultraviolet light-emitting diode includes the ultraviolet light-emitting diode epitaxial structure described in the first aspect of the embodiments of the present invention.

[0014] In the third aspect of the embodiments of the present invention, an electronic device is provided, and the electronic device includes the ultraviolet light-emitting diode described in the second aspect of the embodiments of the present invention.

[0015] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0016] The ultraviolet light-emitting diode epitaxial structure proposed by the present invention, by growing a multi-period composite regulation layer between the first AlN layer and the n-type Al x Ga 1-x N contact layer, to reduce the first AlN layer and the n-type Al x Ga 1-xThe lattice mismatch between the N contact layers regulates the warpage of the ultraviolet light-emitting diode epitaxial wafer, filters the dislocations extending upward in the first AlN layer, and reduces the compressive stress of the n-type Al x Ga 1-x N contact layer, improves the crystal quality, and further enhances the light-emitting efficiency of the device. Description of the Drawings

[0017] The drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. By describing the exemplary embodiments of the present invention in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present invention will become more apparent. In the drawings:

[0018] Figure 1 It is a schematic structural diagram of the ultraviolet light-emitting diode epitaxial structure described in Embodiment 1 of the present invention;

[0019] Figure 2 It is a schematic structural diagram of the multi-period composite regulation layer described in Embodiment 1 of the present invention;

[0020] Figure 3 It is a cross-sectional TEM image of the multi-period composite regulation layer described in Embodiment 1 of the present invention;

[0021] Figure 4 It is a SIMS image of the multi-period composite regulation layer described in Embodiment 1 of the present invention;

[0022] Figure 5 It is a cross-sectional TEM image of the epitaxial structure without the multi-period composite regulation layer in Embodiment 1 of the present invention;

[0023] Figure 6 It is a cross-sectional TEM image of the epitaxial structure including the multi-period composite regulation layer in Embodiment 1 of the present invention;

[0024] Description of the reference numerals

[0025] 1. Substrate, 2. First AlN layer, 3. Multi-period composite regulation layer, 4. n-type Al x Ga 1-x N contact layer, 5. Multi-quantum well light-emitting layer, 6. p-type Al y Ga 1-y N blocking layer, 7. p-type GaN layer;

[0026] 3-1. Second AlN layer, 3-2. Al m Ga 1-m N layer, 3-3. Al n Ga 1-n N layer, 3-4. Al k Ga1-k N layers. Detailed implementation manners

[0027] The preferred implementation manners of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred implementation manners of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the implementation manners set forth herein. On the contrary, these implementation manners are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0028] Example 1

[0029] As Figure 1 shown, this example proposes an ultraviolet light-emitting diode epitaxial structure, which includes a substrate 1, a first AlN layer 2, a multi-period composite regulation layer 3, an n-type Al x Ga 1-x N contact layer 4, a multi-quantum well light-emitting layer 5, a p-type Al y Ga 1-y N barrier layer 6, and a p-type GaN layer 7 grown in sequence from bottom to top.

[0030] Specifically, in this example, the multi-period composite regulation layer 3 is located between the AlN layer and the n-type Al x Ga 1-x N contact layer 4. The multi-period composite regulation layer 3 includes a plurality of periodic structures. The plurality of periodic structures are also grown in sequence from bottom to top. Each periodic structure includes a second AlN layer 3-1, an Al m Ga 1-m N layer 3-2, an Al n Ga 1-n N layer 3-3, and an Al k Ga 1-k N layer 3-4 grown in sequence from bottom to top, as Figure 2 and Figure 3 shown. Among them, the number of periodic structures does not exceed 100. The Al component and thickness between each layer in each periodic structure are also different. The Al component is expressed as 0 < n < x < k < m < 1. The thickness relationship of each layer is that the thickness of the second AlN layer 3-1 ≤ the thickness of the Al m Ga 1-m N layer 3-2 < the thickness of the Al n Ga 1-n N layer 3-3 < the thickness of the Al k Ga 1-k N layer 3-4.

[0031] Further, in this embodiment, the growth temperature of the multi-period composite control layer 3 is 1000 °C to 1250 °C, and the growth pressure is 30 torr to 150 torr. During the epitaxial growth of the multi-period composite control layer 3, the flow rate of TMAl is maintained constant, and the Al component of each layer in the periodic structure of the multi-period composite control layer 3 is controlled by adjusting the flow rate of the TMGa source, so as to achieve that the relationship of the Al components of each layer satisfies 0 < n < x < k < m < 1. As Figure 4 can be seen, the intensity of the Ga element changes periodically with the regulation of the flow rate of the TMGa source during the epitaxial growth process.

[0032] Figure 5 shows a cross-sectional TEM image of the epitaxial structure without the multi-period composite control layer 3. It can be seen that there are a large number of dislocation lines extending upward from the lower first AlN layer 2 in the n-type Al x Ga 1-x N contact layer 4. At the same time, at the contact position between the first AlN layer 2 and the n-type Al x Ga 1-x N contact layer 4, there are many misfit dislocations generated due to large lattice mismatch. In contrast, Figure 6 shows a cross-sectional TEM image of the epitaxial structure including the multi-period composite control layer 3 proposed in this embodiment. It can be clearly seen that Figure 6 in the n-type Al x Ga 1-x N contact layer 4, the dislocations are fewer than those in Figure 5 in the n-type Al x Ga 1-x N contact layer 4. Therefore, by growing the multi-period composite control layer 3 between the first AlN layer 2 and the n-type Al x Ga 1-x N contact layer 4, the lattice mismatch between the first AlN layer 2 and the n-type Al x Ga 1-x N contact layer 4 can be effectively reduced, the compressive stress of the n-type Al x Ga 1-x N contact layer 4 can be reduced, and the dislocations extending upward from the first AlN layer 2 can be filtered, ultimately improving the crystal quality.

[0033] Embodiment 2

[0034] This embodiment proposes an ultraviolet light-emitting diode, which includes the ultraviolet light-emitting diode epitaxial structure described in Embodiment 1. The ultraviolet light-emitting diode epitaxial structure can refer to the content recorded in Embodiment 1, and will not be elaborated in this embodiment.

[0035] Embodiment 3

[0036] This embodiment provides an electronic device, which includes an ultraviolet light-emitting diode. For specific details, refer to the content described in Embodiment 1 and Embodiment 2, and this embodiment will not be elaborated here.

[0037] The above describes the embodiments of the present invention. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. An ultraviolet light-emitting diode epitaxial structure, characterized in that, It includes a substrate, a first AlN layer, a multi-period composite regulation layer, an n-type Al x Ga 1-x N contact layer, a multi-quantum well light-emitting layer, a p-type Al y Ga 1-y N blocking layer, and a p-type GaN layer, wherein the multi-period composite regulation layer includes a plurality of periodic structures grown successively from bottom to top, and each of the periodic structures includes a second AlN layer, an Al m Ga 1-m N layer, an Al n Ga 1-n N layer, and an Al k Ga 1-k N layer grown successively from bottom to top. Among them, the Al components in the n-type Al x Ga 1-x N contact layer, the Al m Ga 1-m N layer, the Al n Ga 1-n N layer, and the Al k Ga 1-k N layer are different; The n-type Al x Ga 1-x N contact layer, Al m Ga 1-m N layer, Al n Ga 1-n N layer and Al k Ga 1-k The Al component in the N layer is: 0 < n < x < k < m < 1; In the periodic structure, the thickness of the second AlN layer ≤ the thickness of the Al m Ga 1-m N layer < the thickness of the Al n Ga 1-n N layer < the thickness of the Al k Ga 1-k N layer.

2. The ultraviolet light-emitting diode epitaxial structure according to claim 1, characterized in that, the number of the periodic structures is 2 to 100.

3. The ultraviolet light-emitting diode epitaxial structure according to claim 1, characterized in that, the growth temperature of the multi-period composite regulation layer is 1000 °C to 1250 °C.

4. The ultraviolet light-emitting diode epitaxial structure according to claim 1, characterized in that, the growth pressure of the multi-period composite regulation layer is 30 torr to 150 torr.

5. The ultraviolet light-emitting diode epitaxial structure according to claim 1, characterized in that, The n-type Al x Ga 1-x In the N contact layer, 0.4 ≤ x ≤ 1.

6. The ultraviolet light-emitting diode epitaxial structure according to claim 1, characterized in that, The p-type Al y Ga 1-y In the N blocking layer, 0.5 ≤ y ≤ 1.

7. An ultraviolet light-emitting diode, characterized in that, the ultraviolet light-emitting diode comprises the ultraviolet light-emitting diode epitaxial structure according to any one of claims 1 to 6.

8. An electronic device, characterized in that, the electronic device comprises the ultraviolet light-emitting diode according to claim 7.

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