DUV LED photoelectric integrated device capable of realizing carrier circulation injection

Abstract

The invention relates to a DUV LED photoelectric integrated device capable of realizing carrier circulation injection. The SBD and the DUV LED are transversely integrated. The SBD sequentially comprises a substrate, a buffer layer, an N-Al < x > Ga < 1-x > N layer, an intrinsic Al < y > Ga < 1-y > N absorption layer, a first N-ohmic electrode and a Schottky electrode in the epitaxial growth direction. The DUV LED sequentially comprises a substrate, a buffer layer, an N-Al < x > Ga < 1-x > N layer, an intrinsic Al < y > Ga < 1-y > N absorption layer, an N-semiconductor transmission layer, a multi-quantum well layer, a P-type electron blocking layer, a P-semiconductor transmission layer, a second N-ohmic electrode and a P-ohmic electrode in the epitaxial growth direction. According to the invention, a photoelectric conversion function can be realized, holes are circularly injected into the LED, and the injection efficiency is improved; under the driving of alternating current, low-heating and low-power-consumption work is carried out; meanwhile, the method belongs to homogeneous integration, the technological process is simple, and the cost is low.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and more specifically to a DUVLED optoelectronic integrated device capable of realizing carrier cyclic injection. Background Art

[0002] Gallium nitride (GaN) has the advantages of large bandgap, high mobility, high breakdown voltage, high energy conversion efficiency, etc., so it has a wide range of applications in the fields of semiconductor light-emitting, electronic power devices, etc. In the field of semiconductor light-emitting, GaN-based DUVLED is gradually replacing mercury-based ultraviolet light sources due to its advantages such as long working life, high reliability, environmental protection and energy saving; in the field of electronic power, the breakdown electric field strength of GaN is much higher than that of silicon, which allows GaN-based devices to operate at higher voltages while maintaining low leakage current, making it an ideal material for making high-performance SBDs (Schottky devices). Therefore, the homogeneous integration of DUV LEDs and SBDs with photoelectric conversion functions in the present invention is feasible.

[0003] Traditional DUV LEDs are generally powered by DC and have a relatively low operating voltage of 3-5V. Therefore, in order to be popularized and applied, traditional DUV LEDs are generally connected to LED drivers (transformers and AC-DC converters), which increases circuit complexity and technical difficulty. To solve this problem, the current relatively novel solution is to homogeneously integrate DUV LEDs with SBDs. However, the DUV LEDs in this solution are difficult to achieve high injection efficiency due to problems such as large Mg activation energy and low hole mobility. Summary of the invention

[0004] In order to solve the problem of low injection efficiency and inability to directly access alternating current in the prior art DUV LED, the present invention provides a DUV LED optoelectronic integrated device that can realize carrier cyclic injection. The device integrates an SBD on the basis of an independent LED, so that the LED can be directly connected to alternating current for use; then, by growing a waveguide layer between the LED and the SBD, the light emitted by the LED passes through the waveguide layer and enters the SBD, forming a photoelectric effect, generating electron-hole pairs, and under the action of an external electric field and a polarization electric field, the SBD has a photoelectric conversion function, realizes hole circulation, and enables holes to be cyclically injected into the LED active area, thereby improving the hole injection efficiency of the LED. The present invention has the following advantages: a) realizes the photoelectric conversion function, enables holes to be cyclically injected into the LED, and improves the injection efficiency; b) can perform low heat generation and low power consumption under the drive of alternating current; c) homogeneous integration, simple process flow, and low cost.

[0005] To achieve the above purpose, the technical solutions adopted are as follows:

[0006] A DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection, the device comprising: a buffer layer (2) on a substrate (1), N-Al x Ga 1-x N layer (3), N-Al x Ga 1-x The N layer (3) consists of two parts: a ring-shaped N-Al x Ga 1-x The N layer (3) is located at the outer edge of the buffer layer (2). x Ga 1-x The N layer (3) is located at the center of the buffer layer (2), and the waveguide layer (10) is located between the two. x Ga 1-x The middle of the upper surface of the N layer (3) is a circular intrinsic Al y Ga 1- y N absorption layer (4); annular N-Al x Ga 1-x The N layer (3) is made of intrinsic Al y Ga 1-y N absorption layer (4), intrinsic Al y Ga 1-y An N-semiconductor transmission layer (5) is disposed on the N absorption layer (4); the N-semiconductor transmission layer (5) is divided into two layers of equal thickness, the outer edge of the upper layer is cut off, and above the uncut portion, there are a multi-quantum well layer (6), a P-type electron blocking layer (7), and a P-semiconductor transmission layer (8) in sequence; a ring-shaped second N-ohm electrode (12) is disposed on the upper surface of the cut-off portion; and a P-ohm electrode (14) is disposed on the inner side of the upper surface of the P-semiconductor transmission layer (8);

[0007] Round N-Al x Ga 1-x The outer side of the upper surface of the N layer (3) is covered with a first N-ohm electrode (11); between the P-ohm electrode (14) and the first N-ohm electrode (11), an interconnection metal (13) is covered;

[0008] Circular intrinsic Al y Ga 1-y The center of the N absorption layer (4) is a circular Schottky electrode (15); the diameter of the Schottky electrode (15) is the circular intrinsic Al y Ga 1-y 60% to 90% of the diameter of the N absorption layer (4); the circular intrinsic Al y Ga 1-y The diameter of the N absorption layer (4) is a circular N-Al x Ga 1-x20% to 80% of the diameter of the N layer (3);

[0009] P-semiconductor transport layer (8), circular N-Al x Ga 1-x N layer (3), circular intrinsic Al y Ga 1-y The exposed portions of the N absorption layer (4) and the upper layer of the N-semiconductor transport layer (5), as well as the sidewalls of the portion above the buffer layer (2), are covered with an insulating layer;

[0010] N-Al x Ga 1-x The projected area of ​​the N layer (3) is 20% to 80% of the area of ​​the buffer layer (2); the annular N-Al x Ga 1-x N layer (3) and circular N-Al x Ga 1-x The spacing of the N layer (3) is 50 to 200 μm;

[0011] The exposed area of ​​the upper layer of the N-semiconductor transport layer (5) is 20% to 80% of the projected area of ​​the N-semiconductor transport layer (5);

[0012] The waveguide layer (10) is made of SiO2 or Al2O3 and has a thickness of 500nm to 5μm;

[0013] The interconnect metal (13) is made of Ni / Au, Cr / Au or Ni / Al;

[0014] The insulating layer (9) is made of SiO2 or Al2O3 and has a thickness of 500nm to 5μm;

[0015] The material of the first N-ohm electrode (11) is Al / Au, Cr / Au or Ti / Al / Ti / Au; the material of the Schottky electrode (15) is Ni / Au;

[0016] The material of the second N-ohm electrode (12) is Al / Au, Cr / Au or Ti / Al / Ti / Au; the material of the P-ohm electrode (14) is Ni / Au;

[0017] The substrate (1) is made of sapphire, AlN, GaN, Si or SiC, and is divided into polar substrate and semi-polar substrate according to the epitaxial growth direction;

[0018] The material of the buffer layer (2) is AlN, and its thickness is 500nm-5μm;

[0019] The N-Al x Ga 1-xN layer (3), whose component coefficient is 0.5≤x≤0.8, 0.2≤1-x≤0.5, and whose thickness is 500nm~5μm;

[0020] The intrinsic Al y Ga 1-y N absorption layer (4), whose component coefficient is 0≤y≤0.4, 0.6≤1-y≤1, and whose thickness is 5nm~5μm, wherein x>y;

[0021] The material of the N-semiconductor transmission layer (5) is Al x1 Ga 1-x1 N, the coefficients of each component are 0.5≤x1≤0.8, 0.2≤1-x1≤0.5, and its thickness is 5nm~5μm;

[0022] The middle region and edge region of the multi-quantum well layer (6) are etched, and the projected area thereof is consistent with the upper area of ​​the N-semiconductor transmission layer (5). The structure thereof is Al x2 Ga 1-x2 N / A x3 Ga 1-x3 N, where the coefficients of each component are 0.55≤x2≤0.8, 0.2≤1-x2≤0.45, 0.45≤x3≤0.6, 0.4≤1-x3≤0.55, where x2>x3; the bandgap width of the quantum barrier is greater than the bandgap width of the quantum well, the number of quantum wells is greater than or equal to 1, and the quantum barrier Al x2 Ga 1-x2 N thickness is 5 to 50 nm, quantum well Al x3 Ga 1-x3 N thickness is 1 to 20 nm;

[0023] The material of the P-type electron blocking layer (7) is Al x4 Ga 1-x4 N, each component is 0.55≤x4≤1, 0≤1-x4≤0.45, and its thickness is 30nm~5μm;

[0024] The material of the P-semiconductor transmission layer (8) is Al x5 Ga 1-x5 N, its composition is 0.4≤x5≤1, 0≤1-x5≤0.6, and its thickness is 100nm~5μm;

[0025] A method for manufacturing a DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection, the specific steps of which are as follows:

[0026] By using either molecular beam epitaxy (MBE) equipment or metal organic chemical vapor deposition (MOCVD) equipment, an initial substrate is grown along the epitaxial growth direction, and then a portion of the substrate is etched selectively to form each layer of a laterally integrated DUV LED and a SBD with a photoelectric conversion function on the device.

[0027] The essential features of the present invention are:

[0028] In the present invention, on the basis of homogeneous integration of DUV LED and SBD, we grow a waveguide layer between DUV LED and SBD, so that the light emitted by DUV LED passes through the waveguide layer and enters SBD. After SBD absorbs photons, electron-hole pairs are generated, thereby making SBD with photoelectric conversion function. Its main working principle is: SBD intrinsic Al y Ga 1-y The Al content of the N absorption layer (4) is lower than that of the Al in the multi-quantum well layer. x3 Ga 1-x3 N Al component, so that the SBD intrinsic Al y Ga 1-y The N absorption layer (4) absorbs the light emitted by the DUV LED, generates a photoelectric effect, forms electron-hole pairs, and realizes photoelectric conversion under the action of an external electric field and a polarization electric field, promotes hole circulation, and improves injection efficiency.

[0029] The beneficial effects of the present invention are as follows:

[0030] (1) The present invention discloses a DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection. The present invention adopts Al x Ga 1-x N / A y Ga 1-y N heterojunction structure to make SBD, in which the intrinsic Al y Ga 1-y The Al component of the N absorption layer (4) is relatively low. The low Al component makes the SBD absorb light, thereby generating electron-hole pairs. Under the action of the external electric field and the polarization electric field, photoelectric conversion is achieved, and hole circulation is promoted (see Fig. 9 ), which increases the injection efficiency of DUV LED by about 20% (see Fig.10 ).

[0031] (2) In addition, conventional LEDs are generally powered by direct current, and the operating voltage is relatively low, generally 3-5 V. Therefore, in order to be popularized and applied, conventional DUV LEDs are generally connected to LED drivers (transformers and AC-DC converters), which increases circuit complexity and technical difficulty. However, the present invention homogeneously integrates the DUV LED with the SBD having a photoelectric conversion function, and utilizes the unidirectional conductivity of the SBD, so that the present invention can work directly under an AC power supply.

[0032] (3) The DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection in the present invention adopts a homogeneous integration method, has a simple manufacturing process, is easy to operate, has strong repeatability, and has a low production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The top view and the front view of the DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection obtained in the embodiment.

[0034] Figure 2 It is a cross-sectional view of a DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection obtained in the embodiment.

[0035] Figure 3 This is a schematic diagram of the initial substrate structure in the present invention.

[0036] Figure 4 In the present invention, intrinsic Al is exposed by photolithography and deep etching. y Ga 1-y Schematic diagram of the N absorber layer.

[0037] Figure 5 It is a schematic diagram of isolating a single device by photolithography and etching in the present invention.

[0038] Figure 6 It is a schematic diagram of exposing one side of the LED to the N-semiconductor transmission layer by photolithography and etching in the present invention, and a schematic diagram of exposing the middle of the SBD to the N-semiconductor transmission layer by photolithography and etching.

[0039] Figure 7 In the present invention, the intrinsic Al is exposed in the middle of the SBD by photolithography and etching. y Ga 1-y Schematic diagram of the N absorption layer.

[0040] Figure 8 Schematic diagram of growing the insulating layer and the waveguide layer by photolithography and ALD in the present invention.

[0041] Fig. 9 This is a schematic diagram of the principle of realizing photoelectric conversion, promoting hole circulation, and improving injection efficiency in the present invention.

[0042] Fig.10 This is a diagram of the lateral hole concentration in the quantum well of the DUV LED in the present invention.

[0043] In the figure, 1. substrate, 2. buffer layer, 3. N-Al x Ga 1-x N layer, 4. Intrinsic Al y Ga 1-y N absorption layer, 5. N-semiconductor transport layer, 6. Multiple quantum well layer, 7. P-type electron blocking layer, 8. P-semiconductor transport layer, 9. Insulation layer, 10. Waveguide layer, 11. First N-ohm electrode, 12. Second N-ohm electrode, 13. Interconnect metal, 14. P-ohm electrode, 15. Schottky electrode. DETAILED DESCRIPTION

[0044] The present invention is further described below in conjunction with embodiments and drawings, but this is not intended to limit the scope of protection of the claims of this application.

[0045] like Figure 1 and Figure 2 As shown, the DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection in the present invention comprises:

[0046] The substrate (1) is provided with a buffer layer (2), and the surface of the buffer layer (2) is distributed with N-Al x Ga 1-x N layer (3), N-Al x Ga 1-x The N layer (3) consists of two parts: a ring-shaped N-Al x Ga 1-x The N layer (3) is located at the outer edge of the buffer layer (2). x Ga 1-x The N layer (3) is located at the center of the buffer layer (2), and the waveguide layer (10) is located between the two. x Ga 1-x The middle of the upper surface of the N layer (3) is a circular intrinsic Al y Ga 1-y N absorption layer (4); annular N-Al x Ga 1-x The N layer (3) is made of intrinsic Al y Ga 1-y N absorption layer (4), intrinsic Al y Ga 1-yAn N-semiconductor transmission layer (5) is disposed on the N absorption layer (4); the N-semiconductor transmission layer (5) is divided into two layers of equal thickness, the outer edge of the upper layer is cut off, and above the uncut portion, there are a multi-quantum well layer (6), a P-type electron blocking layer (7), and a P-semiconductor transmission layer (8) in sequence; a ring-shaped second N-ohm electrode (12) is disposed on the upper surface of the cut-off portion; and a P-ohm electrode (14) is disposed on the inner side of the upper surface of the P-semiconductor transmission layer (8);

[0047] The waveguide layer (10) and the adjacent exposed circular N-Al x Ga 1-x The upper surface of the N layer (3) is covered with a first N-ohm electrode (11); the side wall between the P-ohm electrode (14) and the first N-ohm electrode (11) is covered with an interconnection metal (13);

[0048] Circular intrinsic Al y Ga 1-y The center of the N absorption layer (4) is a circular Schottky electrode (15); the diameter of the Schottky electrode (15) is the circular intrinsic Al y Ga 1-y 60-90% of the diameter of the N absorption layer (4); the circular intrinsic Al y Ga 1-y The diameter of the N absorption layer (4) is a circular N-Al x Ga 1-x 20-80% of the diameter of the N layer (3);

[0049] Semiconductor transport layer (8), circular N-Al x Ga 1-x N layer (3), circular intrinsic Al y Ga 1-y The exposed portions of the N absorption layer (4) and the upper layer of the N-semiconductor transport layer (5), as well as the sidewalls of the portion above the buffer layer (2), are covered with an insulating layer;

[0050] Al x Ga 1-x The projected area of ​​the N layer (3) is 20% to 80% of the area of ​​the buffer layer (2); the annular N-Al x Ga 1-x N layer (3) and circular N-Al x Ga 1-x The spacing of the N layer (3) is 50 to 200 μm;

[0051] The buffer layer (2) is made of AlN and has a thickness of 2 μm;

[0052] The exposed area of ​​the upper layer of the N-semiconductor transport layer (5) is 20%-80% of the projected area of ​​the N-semiconductor transport layer (5);

[0053] In summary, the circular SBD includes, in order along the epitaxial growth direction: a substrate (1), a buffer layer (2), an N-Al x Ga 1-x N layer (3), intrinsic Al y Ga 1-y N absorption layer (4), and a first N-ohm electrode (11) and a Schottky electrode (15); the annular DUV LED comprises, in sequence along the epitaxial growth direction: a substrate (1), a buffer layer (2), an N-Al x Ga 1-x N layer (3), intrinsic Al y Ga 1-y N absorption layer (4), N-semiconductor transmission layer (5), multi-quantum well layer (6), P-type electron blocking layer (7), P-semiconductor transmission layer (8), and a second N-ohmic electrode (12) and a P-ohmic electrode (14).

[0054] Substrate (1), buffer layer (2), N-Al x Ga 1-x N layer (3), intrinsic Al y Ga 1-y An N absorption layer (4), an N-semiconductor transmission layer (5), a multi-quantum well layer (6), a P-type electron blocking layer (7), a P-semiconductor transmission layer (8), and an insulating layer (9) are sequentially arranged along an epitaxial growth direction.

[0055] Figure 1 The structure shown shows that in the present invention, a second N-ohm electrode (12) and a P-ohm electrode (14) are grown on the surface of the DUV LED by electron beam evaporation; a first N-ohm electrode (11) and a Schottky electrode (15) are grown on the surface of the SBD; and an interconnecting metal (13) is grown between the DUV LED and the SBD.

[0056] Example 1

[0057] A DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection comprises a ring-shaped DUV LED laterally integrated on the same substrate, an SBD at the center, a waveguide layer (10) located therebetween, and an interconnecting metal (13) (in the form of a side wall portion + a ring-shaped portion) connecting a first N-ohm electrode and a P-ohm electrode.

[0058] The DUV LED comprises, in sequence along the epitaxial growth direction, a substrate (1), a buffer layer (2), an N-Al x Ga 1-x N layer (3), intrinsic Aly Ga 1-y N absorption layer (4), N-semiconductor transmission layer (5); wherein the diameter of the substrate is 1500 μm; N-Al x Ga 1-x In the N layer (3), x represents the aluminum component, and x = 0.5, intrinsic Al y Ga 1-y In the N absorption layer (4), y represents the aluminum component, and y=0.4; the N-semiconductor transmission layer (5) is divided into two parts, the lower layer is completely covered with intrinsic Al y Ga 1-y The N absorption layer (4) has a thickness of 0.5 μm; the projection area of ​​the upper layer is 80% of the area of ​​the lower layer, and the thickness is 0.5 μm; the total thickness of the N-semiconductor transmission layer (5) is 1 μm; the upper layer of the N-semiconductor transmission layer (5) is a multi-quantum well layer (6), a P-type electron blocking layer (7), and a P-semiconductor transmission layer (8) in sequence; wherein the multi-quantum well layer (6) comprises 6 quantum barriers Al with a thickness of 10 nm. x2 Ga 1-x2 N and 5 quantum wells Al with a thickness of 3nm x3 Ga 1-x3 N, x2 represents the Al component of the quantum barrier, and x2 = 0.55, x3 represents the Al component of the quantum well, and x3 = 0.45; P-type electron blocking layer (7) Al x4 Ga 1-x4 In N, x4 represents Al component, and x4=0.6, and its thickness is 30nm; P-semiconductor transport layer (8) Al x5 Ga 1-x5 In N, x5 represents the Al component, and x5=0.4, the outer side of its upper surface is a ring-shaped high dielectric constant insulating layer as a current limiting hole, the material of which is SiO2, the thickness is 0.5μm, and the width of the ring is 50μm; the ring-shaped P-ohm electrode (14) is located on the inner side of the upper surface of the P-semiconductor transmission layer (8); the ring-shaped second N-ohm electrode (12) is located in the center of the upper surface of the N-semiconductor transmission layer (5), and the width is 50μm.

[0059] The SBD comprises, in sequence along the epitaxial growth direction, a substrate (1), a buffer layer (2), an N-Al x Ga 1-x N layer (3), intrinsic Al y Ga 1-y N absorption layer (4); wherein N-Al x Ga 1-x The N layer (3) has an Al component represented by x, where x = 0.5 and a thickness of 0.5 μm. y Ga 1-yThe N absorption layer (4) is represented by Al component y, and y = 0.4, and its projected area is N-Al x Ga 1-x 80% of the N layer (3), with a thickness of 2 μm; intrinsic Al y Ga 1-y The outer side of the upper surface of the N absorption layer (4) is a ring-shaped high dielectric constant insulating layer as a current limiting hole, which is made of SiO2, has a thickness of 0.5 μm, and a width of 5 μm; N-Al x Ga 1-x The inner side of the upper surface of the N layer (3) is a ring-shaped high dielectric constant insulating layer as a current limiting hole, which is made of SiO2, has a thickness of 0.5 μm, and a width of 10 μm; the circular Schottky electrode (15) is located on the intrinsic Al y Ga 1-y The center of the upper surface of the N absorption layer (4) has a diameter of 90 μm; the first annular N-ohmic electrode (11) is located at the N-Al x Ga 1-x The width of the outer side of the upper surface of the N layer (3) is 50 μm.

[0060] The waveguide layer (10) is on the buffer layer (2) and between the LED and the SBD, and is made of SiO2 with a thickness of 0.5 μm. The interconnection metal (13) is grown on the inner wall of the annular LED and the waveguide layer, and connects the first N-ohm electrode and the P-ohm electrode, and is made of Ni / Au.

[0061] The method for preparing a DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection is as follows:

[0062] In the first step, in a MOCVD reactor, the substrate (1) is baked at a high temperature of 1300°C to remove foreign matter on the surface of the substrate (1), and then the buffer layer (2), N-Al x Ga 1-x N layer (3), intrinsic Al y Ga 1-y N absorption layer (4), N-semiconductor transmission layer (5), multi-quantum well layer (6), P-type electron blocking layer (7), P-semiconductor transmission layer (8); wherein the thickness of the substrate (1) is 3 μm, the thickness of the buffer layer (2) is 2 μm, the thickness of the N-Al x Ga 1-x The thickness of the N layer (3) is 0.5 μm, and the intrinsic Al y Ga 1-yThe total thickness of the N absorption layer (4) is 2 μm, the total thickness of the N-semiconductor transport layer (5) is 1 μm, the thickness of the multi-quantum well layer (6) is 75 nm, the thickness of the P-type electron blocking layer (7) is 30 nm, and the thickness of the P-semiconductor transport layer (8) is 100 nm; Figure 3 As shown;

[0063] In the second step, on the substrate obtained in the first step, selective etching is performed to N-Al x Ga 1-x The position of the N layer (3) makes the intrinsic Al y Ga 1-y The N absorption layer (4) and the epitaxial layers above are divided into a circular middle region and an annular edge region, wherein the diameter of the middle circle is 300 μm and the etching depth is 3.205 μm; Figure 4 As shown;

[0064] In the third step, on the substrate obtained in the second step, x Ga 1-x On the N layer (3), a step is formed by photolithography and etching to expose the epitaxial structure of the buffer layer (2), so that the N-Al x Ga 1-x The N layer (3) is divided into a circular middle area and an annular edge area, wherein the diameter of the middle circle is 500 μm and the etching depth is 0.5 μm; Figure 5 As shown;

[0065] In the fourth step, on the substrate obtained in the third step, by photolithography and dry etching processes, the N-semiconductor transmission layer (5) is exposed on one side of the LED and the epitaxial wafer structure of the N-semiconductor transmission layer (5) is exposed in the middle of the SBD, wherein the etching depth is 0.705 μm; Figure 6 As shown;

[0066] Step 5: On the substrate obtained in step 4, the intrinsic Al is exposed in the middle of the SBD through photolithography and etching processes. y Ga 1-y N absorption layer (4) epitaxial wafer structure; wherein the etching depth is 0.5 μm; Figure 7 As shown;

[0067] Step 6: On the substrate obtained in step 5, a SiO2 insulating layer (9) and a SiO2 waveguide layer (10) are grown by photolithography, ALD and PECVD; the thickness of the SiO2 insulating layer is 0.5 μm; Figure 8 As shown;

[0068] Step 7, on the substrate obtained in step 6, selectively opening SiO2 holes by etching technology;

[0069] Step 8: On the substrate obtained in step 7, electrodes of LED and SBD as well as interconnecting metal (13) are evaporated.

[0070] Thus, a DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection is obtained.

[0071] Fig.10 The quantum well lateral hole concentration distribution of the DUV LED and SBD integrated structure obtained by simulation calculation using Crosslight's APSYS software. As can be seen from the figure, after the light-absorbing layer absorbs light, the hole concentration is increased by about 20%. This shows that the device structure we proposed can effectively improve the hole injection efficiency of the device.

[0072] In the present invention, the DUV LED and the SBD are connected in series. When working, the Schottky electrode is connected to the positive electrode of the power supply, and the second N-ohm electrode is connected to the negative electrode of the power supply. After the device is turned on, the LED emits ultraviolet light, and the ultraviolet light enters the SBD through the waveguide layer, and is absorbed by the intrinsic absorption layer of the SBD. The absorption of photons will generate electron-hole pairs, and the holes in the pairs move under the action of the electric field. The moved holes pass through the interconnecting metal and return to the P-semiconductor transmission layer of the DUV LED. This is the hole cycle, which improves the injection efficiency of the DUV LED by about 20%.

[0073] Example 2

[0074] A DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection comprises a ring-shaped DUV LED laterally integrated on the same substrate, an SBD at the center, a waveguide layer (10) located therebetween, and an interconnecting metal (13) (in the form of a side wall portion + a ring-shaped portion) connecting a first N-ohm electrode and a P-ohm electrode.

[0075] The DUV LED comprises, in sequence along the epitaxial growth direction, a substrate (1), a buffer layer (2), an N-Al x Ga 1-x N layer (3), intrinsic Al y Ga 1-y N absorption layer (4), N-semiconductor transmission layer (5); wherein the diameter of the substrate is 1500 μm; N-Al x Ga 1-x In the N layer (3), x represents the aluminum component, and x = 0.6, intrinsic Al y Ga 1-y In the N absorption layer (4), y represents the aluminum component, and y=0.4; the N-semiconductor transmission layer (5) is divided into two parts, the lower layer is completely covered with intrinsic Al y Ga 1-yThe N absorption layer (4) has a thickness of 0.5 μm; the projection area of ​​the upper layer is 80% of the area of ​​the lower layer, and the thickness is 0.5 μm; the total thickness of the N-semiconductor transmission layer (5) is 1 μm; the upper layer of the N-semiconductor transmission layer (5) is a multi-quantum well layer (6), a P-type electron blocking layer (7), and a P-semiconductor transmission layer (8) in sequence; wherein the multi-quantum well layer (6) comprises 6 quantum barrier Al2O3 layers with a thickness of 10 nm. x2 Ga 1-x2 N and 5 quantum wells Al with a thickness of 3nm x3 Ga 1-x3 N, x2 represents the Al component of the quantum barrier, and x2=0.55, x3 represents the Al component of the quantum well, and x3=0.45; P-type electron blocking layer (7) Al x4 Ga 1-x4 In N, x4 represents Al component, and x4=0.6, and its thickness is 30nm; P-semiconductor transport layer (8) Al x5 Ga 1-x5 In N, x5 represents the Al component, and x5=0.4, the outer side of its upper surface is a ring-shaped high dielectric constant insulating layer as a current limiting hole, the material of which is SiO2, the thickness is 0.5μm, and the width of the ring is 50μm; the ring-shaped P-ohm electrode (14) is located on the inner side of the upper surface of the P-semiconductor transmission layer (8); the ring-shaped second N-ohm electrode (12) is located in the center of the upper surface of the N-semiconductor transmission layer (5), and the width is 50μm.

[0076] The SBD having a photoelectric converter function comprises, in sequence along the epitaxial growth direction, a substrate (1), a buffer layer (2), an N-Al x Ga 1-x N layer (3), intrinsic Al y Ga 1-y N absorption layer (4); wherein N-Al x Ga 1-x The N layer (3) is represented by x, where x = 0.6, and its thickness is 0.5 μm; the intrinsic Al y Ga 1-y The N absorption layer (4) is represented by Al component y, and y = 0.4, and its projected area is N-Al x Ga 1-x 80% of the N layer (3), with a thickness of 2 μm; intrinsic Al y Ga 1-y The outer side of the upper surface of the N absorption layer (4) is a ring-shaped high dielectric constant insulating layer as a current limiting hole, which is made of SiO2, has a thickness of 0.5 μm, and a width of 5 μm; N-Al x Ga 1-xThe inner side of the upper surface of the N layer (3) is a ring-shaped high dielectric constant insulating layer as a current limiting hole, which is made of SiO2, has a thickness of 0.5 μm, and a width of 10 μm; the circular Schottky electrode (15) is located on the intrinsic Al y Ga 1-y The center of the upper surface of the N absorption layer (4) has a diameter of 90 μm; the first annular N-ohmic electrode (11) is located at the N-Al x Ga 1-x The width of the outer side of the upper surface of the N layer (3) is 50 μm.

[0077] The waveguide layer (10) is on the buffer layer (2) and between the LED and the SBD, and is made of SiO2 with a thickness of 0.5 μm. The interconnection metal (13) is grown on the inner wall of the annular LED and the waveguide layer, and connects the first N-ohm electrode and the P-ohm electrode, and is made of Ni / Au.

[0078] The method for preparing a DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection is as follows:

[0079] In the first step, in an MOCVD reactor, the substrate (1) is baked at a high temperature of 1300°C to remove foreign matter on the surface of the substrate (1), and then the buffer layer (2), N-Al x Ga 1-x N layer (3), intrinsic Al y Ga 1-y N absorption layer (4), N-semiconductor transmission layer (5), multi-quantum well layer (6), P-type electron blocking layer (7), P-semiconductor transmission layer (8); wherein the thickness of the substrate (1) is 3 μm, the thickness of the buffer layer (2) is 2 μm, the thickness of the N-Al x Ga 1-x The thickness of the N layer (3) is 0.5 μm, and the intrinsic Al y Ga 1-y The total thickness of the N absorption layer (4) is 2 μm, the total thickness of the N-semiconductor transport layer (5) is 1 μm, the thickness of the multi-quantum well layer (6) is 75 nm, the thickness of the P-type electron blocking layer (7) is 30 nm, and the thickness of the P-semiconductor transport layer (8) is 100 nm; Figure 3 As shown;

[0080] In the second step, on the substrate obtained in the first step, selective etching is performed to N-Al x Ga 1-x The position of the N layer (3) makes the intrinsic Al y Ga 1-yThe N absorption layer (4) and the epitaxial layers above are divided into a circular middle region and an annular edge region, wherein the diameter of the middle circle is 300 μm and the etching depth is 3.205 μm; Figure 4 As shown;

[0081] In the third step, on the substrate obtained in the second step, x Ga 1-x On the N layer (3), a step is formed by photolithography and etching to expose the epitaxial structure of the buffer layer (2), so that the N-Al x Ga 1-x The N layer (3) is divided into a circular middle area and an annular edge area, wherein the diameter of the middle circle is 500 μm and the etching depth is 0.5 μm; Figure 5 As shown;

[0082] In the fourth step, on the substrate obtained in the third step, by photolithography and dry etching processes, the N-semiconductor transmission layer (5) is exposed on one side of the LED and the epitaxial wafer structure of the N-semiconductor transmission layer (5) is exposed in the middle of the SBD, wherein the etching depth is 0.705 μm; Figure 6 As shown;

[0083] Step 5: On the substrate obtained in step 4, the intrinsic Al is exposed in the middle of the SBD through photolithography and etching processes. y Ga 1-y N absorption layer (4) epitaxial wafer structure; wherein the etching depth is 0.5 μm; Figure 7 As shown;

[0084] Step 6: On the substrate obtained in step 5, a SiO2 insulating layer (9) and a SiO2 waveguide layer (10) are grown by photolithography, ALD and PECVD; the thickness of the SiO2 insulating layer is 0.5 μm; Figure 8 As shown;

[0085] Step 7, on the substrate obtained in step 6, selectively opening SiO2 holes by etching technology;

[0086] Step 8: On the substrate obtained in step 7, electrodes of LED and SBD as well as interconnecting metal (13) are evaporated.

[0087] Thus, a DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection is obtained.

[0088] In the present invention, the improvement of DUV LED injection efficiency by Example 1 and Example 2 is similar, both of which are about 20%.

[0089] Obviously, the above embodiments of the present invention are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the claims of the present invention.

[0090] Matters not covered by the present invention are known technologies.

Claims

1. A DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection, characterized in that The device comprises: a buffer layer (2) on a substrate (1), and N-Al x Ga 1-x N layer (3), N-Al x Ga 1-x The N layer (3) consists of two parts: a ring-shaped N-Al x Ga 1-x The N layer (3) is located at the outer edge of the buffer layer (2). x Ga 1-x The N layer (3) is located at the center of the buffer layer (2), and the waveguide layer (10) is located between the two. x Ga 1-x The middle of the upper surface of the N layer (3) is a circular intrinsic Al y Ga 1-y N absorption layer (4); annular N-Al x Ga 1-x The N layer (3) is a ring-shaped intrinsic Al y Ga 1-y N absorption layer (4), intrinsic Al y Ga 1-y An N-semiconductor transmission layer (5) is disposed on the N absorption layer (4); the N-semiconductor transmission layer (5) is divided into two layers of equal thickness, the outer edge of the upper layer is cut off, and above the uncut portion, there are a multi-quantum well layer (6), a P-type electron blocking layer (7), and a P-semiconductor transmission layer (8) in sequence; a ring-shaped second N-ohm electrode (12) is disposed on the upper surface of the cut-off portion; and a P-ohm electrode (14) is disposed on the inner side of the upper surface of the P-semiconductor transmission layer (8); Round N-Al x Ga 1-x The exposed portion of the upper surface of the N layer (3) is covered with a first N-ohm electrode (11) on the outside; an interconnection metal (13) is covered between the P-ohm electrode (14) and the first N-ohm electrode (11); Circular intrinsic Al y Ga 1-y The center of the N absorption layer (4) is a circular Schottky electrode (15); the diameter of the Schottky electrode (15) is the circular intrinsic Al y Ga 1-y 60% to 90% of the diameter of the N absorption layer (4); the circular intrinsic Al y Ga 1-y The diameter of the N absorption layer (4) is a circular N-Al x Ga 1-x 20% to 80% of the diameter of the N layer (3); P-semiconductor transport layer (8), circular N-Al x Ga 1-x N layer (3), circular intrinsic Al y Ga 1-y The exposed parts of the N absorption layer (4) and the upper layer of the N-semiconductor transmission layer (5), as well as the side walls of the part above the buffer layer (2), are all covered with an insulating layer.

2. The DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection as claimed in claim 1, characterized in that N-Al x Ga 1-x The projected area of ​​the N layer (3) is 20% to 80% of the area of ​​the buffer layer (2); the annular N-Al x Ga 1-x N layer (3) and circular N-Al x Ga 1-x The spacing of the N layer (3) is 50 to 200 μm; The exposed area of ​​the upper layer of the N-semiconductor transmission layer (5) is 20% to 80% of the projected area of ​​the N-semiconductor transmission layer (5).

3. The DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection according to claim 1, characterized in that The waveguide layer (10) is made of SiO2 or Al2O 3， Its thickness is 500nm~5μm; The interconnect metal (13) is made of Ni / Au, Cr / Au or Ni / Al; The insulating layer (9) is made of SiO2 or Al2O3 and has a thickness of 500nm to 5μm; The material of the first N-ohm electrode (11) is Al / Au, Cr / Au or Ti / Al / Ti / Au; the material of the Schottky electrode (15) is Ni / Au; The material of the second N-ohm electrode (12) is Al / Au, Cr / Au or Ti / Al / Ti / Au; the material of the P-ohm electrode (14) is Ni / Au; The substrate (1) is made of sapphire, AlN, GaN, Si or SiC, and is divided into polar substrate and semi-polar substrate according to the epitaxial growth direction; The material of the buffer layer (2) is AlN, and its thickness is 500nm-5μm.

4. The DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection according to claim 1, characterized in that The N-Al x Ga 1-x N layer (3), whose component coefficient is 0.5≤x≤0.8, 0.2≤1-x≤0.5, and whose thickness is 500nm~5μm; The intrinsic Al y Ga 1-y N absorption layer (4), whose component coefficient is 0≤y≤0.4, 0.6≤1-y≤1, and whose thickness is 5nm~5μm, wherein x>y; The material of the N-semiconductor transmission layer (5) is Al x1 Ga 1-x1 N, the coefficients of each component are 0.5≤x1≤0.8, 0.2≤1-x1≤0.5, and the thickness is 5nm~5μm; The material of the multi-quantum well layer (6) is Al x2 Ga 1-x2 N / A x3 Ga 1-x3 N, where the coefficients of each component are 0.55≤x2≤0.8, 0.2≤1-x2≤0.45, 0.45≤x3≤0.6, 0.4≤1-x3≤0.55, where x2>x3; the bandgap width of the quantum barrier is greater than the bandgap width of the quantum well, the number of quantum wells is greater than or equal to 1, and the quantum barrier Al x2 Ga 1-x2 N thickness is 5 to 50 nm, quantum well Al x3 Ga 1-x3 The thickness of N is 1 to 20 nm.

5. The DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection according to claim 1, characterized in that The material of the P-type electron blocking layer (7) is Al x4 Ga 1-x4 N, each component is 0.55≤x4≤1, 0≤1-x4≤0.45, and its thickness is 30nm~5μm; The material of the P-semiconductor transmission layer (8) is Al x5 Ga 1-x5 N, its composition is 0.4≤x5≤1, 0≤1-x5≤0.6, and its thickness is 100nm~5μm.

6. The method for preparing a DUV LED optoelectronic integrated device capable of realizing carrier cyclic injection according to claim 1, characterized in that The steps include: By using either molecular beam epitaxy (MBE) equipment or metal organic chemical vapor deposition (MOCVD) equipment, an initial substrate is grown along the epitaxial growth direction, and then a partial area is selected for etching to form each layer of a DUV LED optoelectronic integrated device that can realize carrier cyclic injection on the device.

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