Resonant cavity light emitting diode, manufacturing method thereof and light emitting array structure

Abstract

The invention provides a resonant cavity light emitting diode which comprises a first reflecting layer, a first type semiconductor layer, an active layer and a second type semiconductor layer which are sequentially stacked on a first substrate, a second reflecting layer covers the first side wall of the second type semiconductor layer, and the upper surface of the side, away from the first substrate, of the second type semiconductor layer is a light outlet. The first reflecting layer and the second reflecting layer form a resonant cavity, and light can be reflected for multiple times in the resonant cavity; the first side wall comprises a lower tangency point and an upper tangency point which are arranged from bottom to top, and the tangent slope of the upper tangency point is larger than that of the lower tangency point, that is, the closer to the tangency point at the light outlet, the larger the tangent slope is, the smaller the included angle between the first side wall and the vertical direction is, and light rays reflected many times are easily reflected after reaching the first side wall and are directionally emitted from the upper surface; photons can be accelerated to escape from a light outlet, and the light extraction efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a resonant cavity light emitting diode and a manufacturing method thereof, and a light emitting array structure. Background Art

[0002] With the development of big data and the fifth generation of mobile communication technology, optical network information processing is increasing and high-density broadband communication is improving. As laser light sources, resonant cavity light emitting diodes (RCLED) and vertical cavity surface emitting lasers (VCSEL) are attracting more and more attention.

[0003] An oxide layer with openings is often used in laser light sources to perform lateral control of electrons and photons. However, due to the high complexity and poor stability of the oxidation process, it is difficult to accurately control the oxidation depth. In addition, there is a difference in the thermal expansion coefficients of oxides and semiconductors, which causes stress at the openings in the oxide layer, reducing device reliability and making it difficult to ensure high light extraction efficiency. Summary of the invention

[0004] In view of this, the embodiments of the present application provide a resonant cavity light emitting diode and a manufacturing method thereof, and a light emitting array structure to solve the technical problem of low light extraction efficiency in the prior art.

[0005] According to one aspect of the present application, an embodiment of the present application provides a resonant cavity light emitting diode, comprising: a first reflective layer, a first type semiconductor layer, an active layer, and a second type semiconductor layer stacked in sequence on a first substrate, the second type semiconductor layer comprising a first side wall and an upper surface located on a side of the first side wall away from the first substrate; a second reflective layer, at least covering the first side wall; the upper surface is a light outlet; the first side wall comprises a lower tangent point and an upper tangent point arranged along a first direction, the first direction is a direction from the first substrate to the second type semiconductor layer, and the tangent slope of the upper tangent point is greater than the tangent slope of the lower tangent point.

[0006] According to another aspect of the present application, an embodiment of the present application provides a light-emitting array structure, comprising: a first light-emitting area and a second light-emitting area adjacent to each other, the first light-emitting area comprising the resonant cavity light-emitting diode described in the first aspect; the pixel structure of the second light-emitting area comprising any one of an LED pixel structure, an OLED pixel structure and an LCD pixel structure.

[0007] According to another aspect of the present application, an embodiment of the present application provides a method for manufacturing a resonant cavity light emitting diode, comprising: manufacturing a mask layer on a growth substrate; etching the mask layer to form a through hole exposing the growth substrate, the mask layer constituting a through hole side wall of the through hole, the through hole side wall comprising a first tangent point and a second tangent point located at the first tangent point away from the growth substrate, the tangent slope of the first tangent point being greater than the tangent slope of the second tangent point; epitaxially manufacturing a second type semiconductor layer from the through hole, the first side wall of the second type semiconductor layer matching the shape of the through hole side wall, the first side wall comprising an upper tangent point corresponding to the first tangent point and a lower tangent point corresponding to the second tangent point, the tangent slope of the upper tangent point being greater than the tangent slope of the lower tangent point; manufacturing an active layer, a first type semiconductor layer and a first reflective layer on the second type semiconductor layer; inverting the first substrate; removing the growth substrate and the mask layer; and manufacturing a second reflective layer on the first side wall.

[0008] One of the above technical solutions has the following beneficial effects:

[0009] A resonant cavity light emitting diode provided in an embodiment of the present application includes a first reflective layer, a first type semiconductor layer, an active layer, and a second type semiconductor layer stacked in sequence on a first substrate, the second reflective layer covers a first side wall of the second type semiconductor layer, the upper surface of the second type semiconductor layer away from the first substrate is a light outlet, the first reflective layer and the second reflective layer constitute a resonant cavity, and light can be reflected multiple times in the resonant cavity; the first side wall includes a lower tangent point and an upper tangent point arranged from bottom to top, the tangent slope of the upper tangent point is greater than the tangent slope of the lower tangent point, that is, the closer the tangent point is to the light outlet, the greater the tangent slope is, and the smaller the angle between the first side wall and the vertical direction is, the light reflected multiple times is easily reflected after reaching the first side wall and is emitted directionally from the upper surface, which can accelerate the escape of photons from the light outlet and improve the light extraction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A schematic diagram of the structure of a resonant cavity light emitting diode provided in one embodiment of the present application;

[0011] Figure 2 A schematic diagram of the structure of another resonant cavity light emitting diode provided in one embodiment of the present application;

[0012] Figure 3 A schematic diagram of the structure of another resonant cavity light emitting diode provided in one embodiment of the present application;

[0013] Figure 4 A schematic diagram of the structure of another resonant cavity light emitting diode provided in one embodiment of the present application;

[0014] Figure 5A schematic diagram of the structure of another resonant cavity light emitting diode provided in one embodiment of the present application;

[0015] Figure 6 for Figure 5 A top view of a resonant cavity light emitting diode is provided;

[0016] Figure 7 A schematic diagram of the structure of another resonant cavity light emitting diode provided in one embodiment of the present application;

[0017] Figure 8 A schematic diagram of the structure of another resonant cavity light emitting diode provided in one embodiment of the present application;

[0018] Fig. 9 A resonant cavity light emitting diode arrangement diagram provided in one embodiment of the present application;

[0019] Fig.10 Another resonant cavity light emitting diode arrangement diagram provided in one embodiment of the present application;

[0020] Fig.11 Another resonant cavity light emitting diode arrangement diagram provided in one embodiment of the present application;

[0021] Fig.12 A schematic diagram of a light emitting array structure provided in one embodiment of the present application;

[0022] Fig.13 A schematic diagram of another light emitting array structure provided in one embodiment of the present application;

[0023] Fig.14 A schematic diagram of another light emitting array structure provided in one embodiment of the present application;

[0024] Fig.15 A schematic diagram of a process for manufacturing a resonant cavity light emitting diode provided in one embodiment of the present application;

[0025] Figures 16 to 22 A schematic diagram of the intermediate structure of a resonant cavity light emitting diode provided for manufacturing an embodiment of the present application. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0027] To improve light extraction efficiency, Figure 1A schematic diagram of the structure of a resonant cavity light emitting diode provided in one embodiment of the present application is shown in FIG. Figure 1 As shown, the present application provides a resonant cavity light emitting diode 100, comprising: a first reflective layer 21, a first type semiconductor layer 31, an active layer 32, and a second type semiconductor layer 33 stacked in sequence on a first substrate 11, the second type semiconductor layer 33 comprising a first side wall 331 and an upper surface 332 located on a side of the first side wall 331 away from the first substrate 11; the second reflective layer 22 at least covers the first side wall 331; the upper surface 332 is a light outlet; the first side wall 331 comprises a lower tangent point T1 and an upper tangent point T2 arranged along a first direction X, the first direction X is the direction from the first substrate 11 to the second type semiconductor layer 33, and the tangent slope t2 of the upper tangent point T2 is greater than the tangent slope t1 of the lower tangent point T1.

[0028] Specifically, the first type semiconductor layer 31, the active layer 32 and the second type semiconductor layer 33 are located between the first reflective layer 21 and the second reflective layer 22. The first reflective layer 21 and the second reflective layer 22 constitute the resonant cavity of the resonant cavity light emitting diode. The light generated by the active layer 32 is reflected multiple times in the resonant cavity, so that the light has a narrower wavelength peak, thereby improving the spectral purity. Furthermore, the tangent slope t2 of the upper tangent point T2 is greater than the tangent slope t1 of the lower tangent point T1, that is, the closer the tangent point is to the light outlet, the greater the tangent slope of the first side wall is, and the smaller the angle between the first side wall and the vertical direction is, and the multiply reflected light is easily reflected after reaching the first side wall close to the light outlet and is emitted from the light outlet in a direction, which can accelerate the escape of photons from the light outlet and improve the light extraction efficiency.

[0029] It should be noted that, taking the upper tangent point T2 as an example, the tangent slope t2 refers to the tangent value of the angle between the tangent line of the first side wall at the upper tangent point T2 and the plane where the first substrate 11 is located.

[0030] It should be noted that Figure 1 Only the cross-sectional view of three resonant cavity light emitting diode units is shown.

[0031] Optionally, when the first type semiconductor layer 31 and the second type semiconductor layer 33 are GaN-based materials, the active layer 32 includes a combination of any two of GaN, InGaN, AlGaN and AlInGaN.

[0032] Optionally, when the first type semiconductor layer 31 and the second type semiconductor layer 33 are GaAs-based materials, the active layer 32 includes a combination of any two of GaAs, InGaAs, AlGaAs and AlInGaAs.

[0033] Optionally, when the first type semiconductor layer 31 and the second type semiconductor layer 33 are GaP-based materials, the active layer 32 includes a combination of any two of GaP, InGaP, AlGaP and AlInGaP.

[0034] In one embodiment, Figure 1 As shown, the tangent slope of the first sidewall 331 gradually increases along the first direction X. Specifically, the profile of the first sidewall 331 is a curve that is concave toward the second type semiconductor layer 33 , so that the closer to the light outlet, the greater the tangent value of the tangent point of the first sidewall 331 .

[0035] In one embodiment, Figure 2 A schematic diagram of the structure of another resonant cavity light emitting diode provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the first side wall 331 includes a first portion 3311 and a second portion 3312 located on the side of the first portion 3311 away from the first substrate 11; the first portion 3311 is perpendicular to the first substrate 11; along the first direction X, the tangent slope of the second portion 3312 gradually increases. Specifically, the profile of the second portion 3312 is presented as a curve that is concave toward the second type semiconductor layer 33, so that the closer to the light outlet, the greater the tangent value of the tangent point of the first side wall 331. It should be noted that in the manufacturing process, the second type semiconductor layer 33 is firstly epitaxially manufactured, and after the second type semiconductor layer 33 is epitaxially manufactured to have a constant area and a relatively flat film layer (the area where the first portion 3311 is located), the film layers of other semiconductor materials, such as the active layer 32 and the first type semiconductor layer 31, are then epitaxially manufactured, which can improve the crystal quality of the film layers of other semiconductor materials, thereby improving the photoelectric characteristics of the resonant cavity light emitting diode 200.

[0036] In one embodiment, Figure 3 A schematic diagram of the structure of another resonant cavity light emitting diode provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, along the first direction X, the tangent slopes of the side walls of the first type semiconductor layer 31, the active layer 32, and the second type semiconductor layer 33 gradually increase. Specifically, the side wall profiles of the first type semiconductor layer 31, the active layer 32, and the second type semiconductor layer 33 are generally presented as a curve that is concave toward the first substrate 11, so that the closer to the light outlet, the greater the tangent value of the tangent point of the side wall. It should be noted that in the resonant cavity light emitting diode 300, along the first direction X, the first type semiconductor layer 31, the active layer 32, and the second type semiconductor layer 33 are generally presented as a trend of gradually converging, so that the light is more easily directed upward and toward the light outlet after being reflected by the side wall, which can accelerate the escape of photons from the light outlet and improve the light extraction efficiency.

[0037] In one embodiment, Figure 4A schematic diagram of the structure of another resonant cavity light emitting diode provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, in the resonant cavity light emitting diode 400, the second reflective layer 22 also covers the upper surface 332 of the second type semiconductor layer 33, the sidewalls of the first type semiconductor layer 31, and the sidewalls of the active layer 32. Specifically, the second reflective layer 22 and the first reflective layer 21 form a nearly fully enclosed resonant cavity, which reduces the leakage of light from the sidewalls of the first type semiconductor layer 31 and the active layer 32, increases the number of reflections of light in the resonant cavity, improves the light resonance effect, makes the light have a narrower wavelength peak, and improves the spectral purity.

[0038] In one embodiment, Figure 4 As shown, the reflectivity of the second reflective layer 22 located on the first side wall 331 is higher than the reflectivity of the second reflective layer 22 located on the upper surface 332. Specifically, the upper surface 332 with lower reflectivity is a light outlet, and the light is reflected multiple times in the resonance cavity formed by the first reflective layer 21 and the second reflective layer 22, and finally emitted from the upper surface 332.

[0039] In one embodiment, Figure 1 As shown, the second type semiconductor layer 33 also includes a lower surface 333 close to the first substrate 11, and the area of ​​the upper surface 332 of the second type semiconductor layer 33 is 0.05 to 0.5 times the area of ​​the lower surface 333. Specifically, the area of ​​the upper surface 332 is the area of ​​the light outlet, and the area of ​​the lower surface 333 is close to the projection area of ​​the resonant cavity on the first substrate 11. The area of ​​the light outlet is as small as possible, which can improve the directionality and collimation of the light emission; the projection area of ​​the resonant cavity is as large as possible, that is, the area of ​​the active layer 32 is as large as possible, which can increase the number of photons, improve the internal quantum efficiency, and improve the light extraction efficiency after multiple reflections in the resonant cavity. Optionally, the area of ​​the upper surface 332 is 0.1 times, 0.2 times, 0.3 times or 0.4 times the area of ​​the lower surface 333.

[0040] In one embodiment, the first type semiconductor layer 31 is P-type doped, and the second type semiconductor layer 33 is N-type doped.

[0041] In one embodiment, Figure 5 A schematic diagram of the structure of another resonant cavity light emitting diode provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, the resonant cavity light emitting diode 500 also includes a driving circuit located on the first substrate 11; a first electrode 41, located between the first type semiconductor layer 31 and the first substrate 11, for electrically connecting the first type semiconductor layer and the driving circuit; a second electrode 42, located on the first side wall 331, one end of the second electrode 42 is electrically connected to the second type semiconductor layer 33, and the other end of the second electrode 42 is electrically connected to the driving circuit through an electrode line 421.

[0042] Optionally, Figure 6 for Figure 5 A top view of a resonant cavity light emitting diode is provided, such as Figure 6 As shown, in order to reduce the contact resistance between the second electrode 42 and the second type semiconductor layer 33, the second electrode 42 is an arc shape exceeding 180 degrees; the second electrode 42 is then electrically connected to the driving circuit on the first substrate 11 through the electrode line 421. It should be noted that Figure 6 The outer contour of the second reflective layer 22 is shown as a hexagon, that is, the projection shape of the second type semiconductor layer 33 on the first substrate 11 is a hexagon; optionally, the projection shape of the second type semiconductor layer 33 on the first substrate 11 is a circle, a polygon or other shapes. It should be noted that, Figure 6 The illustrated projection shape of the light outlet on the first substrate 11 is a circle; optionally, the projection shape of the light outlet is a hexagon, a polygon or other shapes.

[0043] Optionally, the material of the first reflective layer 21 is a metal or metal alloy with high reflectivity, such as Al, Ag, Au and alloys thereof, and the end of the first electrode 41 close to the first type semiconductor layer 31 can be made on the first reflective layer 21 to achieve electrical connection between the first type semiconductor layer and the driving circuit; Optionally, the material of the first reflective layer 21 is TiO 2 / SiO 2 、Ti 3 O 5 / SiO 2 、 2 O 5 / SiO 2 、Ti 3 O 5 / Al 2 O 3 、ZrO 2 / SiO 2 or TiO 2 / Al 2 O 3 In the case of a distributed Bragg reflector composed of a pair of oxide materials, one end of the first electrode 41 needs to be in direct contact with the first type semiconductor layer 31 to achieve electrical connection between the first type semiconductor layer and the driving circuit. Optionally, the material of the second reflective layer 22 is selected from the above-mentioned metal or metal alloy with high reflectivity, a distributed Bragg reflector composed of a pair of oxide materials, etc.

[0044] Optionally, the first electrode 41 is an interconnected common electrode, and the second electrode 42 is an independent electrode that provides an electrical signal to each resonant cavity light emitting diode unit; or, the second electrode 42 is an interconnected common electrode, and the first electrode 41 is an independent electrode.

[0045] It should be noted that Figure 5 The driving circuit is not shown in the figure, and the first substrate 11 may be a driving circuit board. The first substrate 11 includes a driving circuit for providing a driving signal to the resonant cavity light emitting diode 500 .

[0046] Alternatively, if Figure 1 As shown, a passivation layer 51 is formed on the sidewalls of the first type semiconductor layer 31, the active layer 32, the second type semiconductor layer 33 and the first reflective layer 32. The material of the passivation layer 51 can be SiO 2 、Al 2 O 3 , SiN, polyimide, photoresist or other photo-patternable polymers, etc. The second electrode 42 is electrically connected to the second type semiconductor layer 33 through the via hole of the passivation layer.

[0047] In one embodiment, Figure 7 A schematic diagram of the structure of another resonant cavity light emitting diode provided in an embodiment of the present application is shown in FIG. Figure 7 As shown, in the resonant cavity light emitting diode 600 , the first electrode 41 is located on the terrace of the first type semiconductor layer 31 , and the second electrode 42 is located on the first sidewall 331 of the second type semiconductor layer 33 .

[0048] In one embodiment, Figure 8 A schematic diagram of the structure of another resonant cavity light emitting diode provided in an embodiment of the present application is shown in FIG. Figure 8 As shown, the second type semiconductor layer 33 includes a lower surface 333 close to the active layer 32, and the areas of the lower surfaces 333 of at least two resonant cavity light emitting diodes are different, so that the emission wavelengths of the two resonant cavity light emitting diodes are different. It should be noted that, taking the material of the active layer 32 as InGaN / GaN as an example, the areas of the lower surfaces 333 of the two resonant cavity light emitting diodes are different, and the areas of the subsequent epitaxial active layers 32 are different. Due to the different doping rates of the In component in the active layers of different areas, the emission wavelengths of the two resonant cavity light emitting diodes finally produced are different. Optionally, the larger the area of ​​the lower surface 333, the shorter the emission wavelength of the resonant cavity light emitting diode.

[0049] In one embodiment, Fig. 9 A resonant cavity light emitting diode arrangement diagram provided in one embodiment of the present application, such as Fig. 9 As shown, the resonant cavity light emitting diodes R100 / G100 / B100 emit red light, green light and blue light respectively, and each pixel unit U1 includes 1 R100, 1 G100 and 1 B100, and form a delta arrangement. Optionally, the resonant cavity light emitting diodes can also form any one of a standard RGB arrangement and a diamond arrangement.

[0050] Optionally, considering that the luminous efficiency of red light is lower than that of green light and blue light, one pixel unit includes a plurality of resonant cavity light emitting diodes emitting red light to balance the proportions of the three colors in one pixel unit. Fig.10 Another resonant cavity light emitting diode arrangement diagram provided in an embodiment of the present application is shown in FIG. Fig.11 Another resonant cavity light emitting diode arrangement diagram provided in an embodiment of the present application is as follows: Fig.10 and Fig.11 As shown, the resonant cavity light emitting diodes R100 / G100 / B100 emit red light, green light and blue light respectively, and each pixel unit U2 includes 2 R100, 1 G100 and 1 B100. Fig.10 As shown, in a pixel unit U2, two R100, one G100 and one B100 are arranged in a staggered manner; Fig.11 As shown, in a pixel unit U2, 2 R100, 1 G100 and 1 B100 are arranged in a standard RGB configuration.

[0051] Based on the same inventive concept, the embodiment of the present application further provides a light emitting array structure, Fig.12 A schematic diagram of a light emitting array structure provided in one embodiment of the present application is shown in FIG. Fig.12 As shown, the present application also provides a light-emitting array structure, including: adjacent first light-emitting area A1 and second light-emitting area A2, the first light-emitting area A1 includes the resonant cavity light-emitting diode P100 described in any one of the above embodiments; the pixel structure P200 of the second light-emitting area A2 includes any one of an LED pixel structure, an OLED pixel structure and an LCD pixel structure.

[0052] Compared with LED pixel structure, OLED pixel structure and LCD pixel structure, the resonant cavity light emitting diode disclosed in the present application can improve light extraction efficiency, brightness and color. Optionally, in the traditional light emitting array structure, there is a problem of low brightness in the border area. The light emitting array structure provided by the present application can set the first light emitting area in the border area and the second light emitting area in the central area to improve the brightness uniformity of the light emitting array structure.

[0053] Optionally, Fig.13 A schematic diagram of another light emitting array structure provided in an embodiment of the present application is shown in FIG. Fig.13 As shown, the first light-emitting area A1 includes resonant cavity light-emitting diodes B101 / G101 / R101 that emit blue light, green light, and red light, respectively, and the second light-emitting area A2 includes pixel structures B201 / G201 / R201 that emit blue light, green light, and red light, respectively. The color arrangement of the resonant cavity light-emitting diodes is the same as the color arrangement of the pixel structure and belongs to the standard RGB arrangement.

[0054] Optionally, Fig.14 A schematic diagram of another light emitting array structure provided in an embodiment of the present application is shown in FIG. Fig.14 As shown, the first light-emitting area A1 and the second light-emitting area A2 are arranged alternately in the row direction, and a resonant cavity light-emitting diode P100 is disposed on one side of each pixel structure P200 to improve the problem of low brightness of the pixel structure P200. Fig.14 As shown, the blue light sub-pixel B300 includes a resonant cavity light emitting diode P100 that emits blue light and a pixel structure P200 that emits blue light, the green light sub-pixel G300 includes a resonant cavity light emitting diode P100 that emits green light and a pixel structure P200 that emits green light, and the red light sub-pixel R300 includes a resonant cavity light emitting diode P100 that emits red light and a pixel structure P200 that emits red light.

[0055] Fig.15 A schematic diagram of a process for manufacturing a resonant cavity light emitting diode provided in one embodiment of the present application. Figures 16 to 22 A schematic diagram of the intermediate structure of a resonant cavity light emitting diode provided in one embodiment of the present application is shown in FIG. Fig.15 As shown, the present application also provides a method for manufacturing a resonant cavity light emitting diode, comprising:

[0056] Step S1, such as Fig.16 As shown, a mask layer 13 is formed on a growth substrate 12 .

[0057] Optionally, the growth substrate 12 includes any one of sapphire, silicon, silicon carbide, silicon germanium or GaN.

[0058] Step S2, such as Fig.17 As shown, the mask layer 13 is etched to form a through hole 131 exposing the growth substrate 12. The mask layer 13 constitutes a through hole sidewall of the through hole 131. The through hole sidewall includes a first tangent point T10 and a second tangent point T20 located on the side of the first tangent point T10 away from the growth substrate 12. The tangent slope t10 of the first tangent point T10 is greater than the tangent slope t20 of the second tangent point T20.

[0059] Optionally, the mask layer 13 is etched by photolithography to form through-hole sidewalls with different tangent slopes.

[0060] Step S3, such as Fig.18 As shown, a second type semiconductor layer 33 is produced by epitaxial growth from the through hole 131, and a first side wall 331 of the second type semiconductor layer 33 matches the shape of the through hole side wall. The first side wall 331 includes an upper tangent point T1 corresponding to the first tangent point T10 and a lower tangent point T2 corresponding to the second tangent point T20, and the tangent slope t1 of the upper tangent point T1 is greater than the tangent slope t2 of the lower tangent point T2.

[0061] Optionally, before forming the second type semiconductor layer 33 , a nucleation layer and a buffer layer are first formed by epitaxial growth at the bottom of the through hole 131 ; when the second type semiconductor layer 33 is a GaN-based material, the material of the nucleation layer is AlN, and the material of the buffer layer is GaN.

[0062] Step S4, such as Fig.19 As shown, an active layer 32 , a first type semiconductor layer 31 and a first reflective layer 21 are manufactured on the second type semiconductor layer 33 .

[0063] Optionally, when the second type semiconductor layer 33 is a GaN-based material, the active layer 32 includes a combination of any two of GaN, InGaN, AlGaN and AlInGaN.

[0064] Step S5, such as Fig. 20 As shown, it is placed upside down on the first substrate 11.

[0065] Optionally, the first substrate 11 is a driving circuit board. Optionally, before step S5, a first electrode electrically connected to the first type semiconductor layer 31 is manufactured; in step S5, the first electrode is electrically connected to the driving circuit board (first substrate 11).

[0066] Step S6, as Fig.21 As shown, the growth substrate 12 and the mask layer 13 are removed.

[0067] Optionally, the growth substrate 12 is removed by laser lift-off. Optionally, the mask layer 13 is removed by etching.

[0068] Alternatively, if Fig. 22 As shown, after step S6, a passivation layer 51 is formed to cover the sidewalls of the first type semiconductor layer 31, the active layer 32 and the second type semiconductor layer 33. Optionally, the passivation layer 51 may cover the upper surface of the second type semiconductor layer 33 away from the first substrate 11.

[0069] Step S7, Figure 1 As shown, the second reflective layer 22 is formed on the first side wall 331. Optionally, the second reflective layer 22 is formed on the passivation layer 51.

[0070] It should be noted that the second type semiconductor layer 33 is first epitaxially grown on a smaller area of ​​the growth substrate 12, and the through hole 131 is laterally epitaxially filled. Taking the material of the second type semiconductor layer 33 as GaN as an example, the dislocation of GaN is mainly a linear dislocation in the

[0001] crystal direction, that is, a linear dislocation extending along the thickness direction of the growth substrate 12. At this time, the smaller the epitaxial growth area of ​​the second type semiconductor layer 33, the lower the dislocation density of GaN, thereby improving the crystal quality of the second type semiconductor layer 33. In addition, the through hole 131 of a specific shape is formed by photolithography patterning the mask layer 13 to obtain a resonant cavity diode of a specific shape, and the process is relatively simple.

[0071] The resonant cavity light emitting diode manufactured by the method provided in this embodiment comprises: a first reflective layer, a first type semiconductor layer, an active layer, and a second type semiconductor layer stacked in sequence on a first substrate, the second reflective layer covers a first side wall of the second type semiconductor layer, the upper surface of the second type semiconductor layer away from the first substrate is a light outlet, the first reflective layer and the second reflective layer constitute a resonant cavity of the resonant cavity light emitting diode, and light can be reflected multiple times in the resonant cavity; the first side wall comprises a lower tangent point and an upper tangent point arranged from bottom to top, the tangent slope of the upper tangent point is greater than the tangent slope of the lower tangent point, that is, the closer the tangent point is to the light outlet, the greater the tangent slope is, and the smaller the angle between the first side wall and the vertical direction is, the light reflected multiple times is easily reflected after reaching the first side wall and is emitted directionally from the upper surface, which can accelerate the escape of photons from the light outlet and improve the light extraction efficiency.

[0072] It should be understood that the term "including" and its variations used in this application are open inclusions, that is, "including but not limited to". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment". In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0073] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A resonant cavity light emitting diode, characterized in that: include: A first reflective layer, a first type semiconductor layer, an active layer, and a second type semiconductor layer are sequentially stacked on a first substrate, wherein the second type semiconductor layer comprises a first sidewall and an upper surface located on a side of the first sidewall away from the first substrate; a second reflective layer, at least covering the first side wall; The upper surface is a light outlet; The first side wall includes a lower tangent point and an upper tangent point arranged along a first direction, the first direction is a direction from the first substrate to the second type semiconductor layer, and a tangent slope of the upper tangent point is greater than a tangent slope of the lower tangent point.

2. The resonant cavity light emitting diode according to claim 1, characterized in that: Along the first direction, the tangent slope of the first side wall gradually increases.

3. The resonant cavity light emitting diode according to claim 1, characterized in that: The first side wall includes a first portion and a second portion located in the first portion away from the first substrate; The first portion is perpendicular to the first substrate; Along the first direction, the slope of the tangent line of the second portion gradually increases.

4. The resonant cavity light emitting diode according to claim 1, characterized in that: Along the first direction, tangent slopes of side walls of the first type semiconductor layer, the active layer and the second type semiconductor layer gradually increase.

5. The resonant cavity light emitting diode according to claim 1, characterized in that: The second reflective layer also covers the upper surface of the second type semiconductor layer, the sidewall of the first type semiconductor layer, and the sidewall of the active layer.

6. The resonant cavity light emitting diode according to claim 5, characterized in that: The reflectivity of the second reflective layer located on the first sidewall is higher than the reflectivity of the second reflective layer located on the upper surface.

7. The resonant cavity light emitting diode according to claim 1, characterized in that: The second type semiconductor layer further includes a lower surface close to the first substrate, and an area of ​​the upper surface of the second type semiconductor layer is 0.05 to 0.5 times an area of ​​the lower surface.

8. The resonant cavity light emitting diode according to claim 1, characterized in that: The first type semiconductor layer is P-type doped, and the second type semiconductor layer is N-type doped.

9. The resonant cavity light emitting diode according to claim 1, characterized in that: Also includes a driving circuit located on the first substrate; a first electrode, located between the first type semiconductor layer and the first substrate, and used to electrically connect the first type semiconductor layer and the driving circuit; A second electrode is located on the first side wall, one end of the second electrode is electrically connected to the second type semiconductor layer, and the other end of the second electrode is electrically connected to the driving circuit through an electrode line.

10. The resonant cavity light emitting diode according to claim 1, characterized in that: The second type semiconductor layer includes a lower surface close to the active layer, At least two of the resonant cavity light emitting diodes have different areas of the lower surfaces, so that the light emission wavelengths of the two resonant cavity light emitting diodes are different.

11. A light emitting array structure, characterized in that: include: The adjacent first light emitting area and the second light emitting area, The first light emitting region comprises a resonant cavity light emitting diode as claimed in any one of claims 1 to 10; The pixel structure of the second light emitting area includes any one of an LED pixel structure, an OLED pixel structure and an LCD pixel structure.

12. A method for manufacturing a resonant cavity light emitting diode, characterized in that: include: forming a mask layer on a growth substrate; Etching the mask layer to form a through hole exposing the growth substrate, the mask layer constituting a through hole sidewall of the through hole, the through hole sidewall comprising a first tangent point and a second tangent point located at the first tangent point and away from the growth substrate, the tangent slope of the first tangent point being greater than the tangent slope of the second tangent point; epitaxially fabricating a second type semiconductor layer from the through hole, wherein a first side wall of the second type semiconductor layer matches the shape of the through hole side wall, the first side wall comprises an upper tangent point corresponding to the first tangent point and a lower tangent point corresponding to the second tangent point, and a tangent slope of the upper tangent point is greater than a tangent slope of the lower tangent point; forming an active layer, a first type semiconductor layer and a first reflective layer on the second type semiconductor layer; being placed upside down on a first substrate; removing the growth substrate and the mask layer; A second reflective layer is formed on the first side wall.

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