Micro-LED structure containing driver and preparation method thereof

Abstract

The invention discloses a micro-LED structure with a driver and a preparation method of the micro-LED structure. The micro-LED structure comprises a gallium nitride (GaN) layer, a mask layer with micropores, a GaN three-dimensional triangular island, a high electron mobility transistor (HEMT) structure and a Micro-LED structure, wherein the upward crystal face of the GaN layer is a non-polar face, the HEMT structure is arranged on the inclined face of one side of the triangular island, and the Micro-LED structure is arranged on the inclined face of the other side of the triangular island. The GaN island of a three-dimensional structure is obtained by utilizing selected area epitaxy and combining with lateral epitaxy, the GaN island naturally forms a bilaterally symmetrical structure due to the crystal attribute, the HEMT and the Micro-LED structure are arranged on the two sides respectively, the HEMT on one side can be directly utilized to drive the Micro-LED on the other side, the problem that a traditional Micro-LED needs to be additionally driven is solved, and the GaN island can be used for driving the LED on the other side. And the constraint that micropores are current when a traditional selective area epitaxy MicroLED structure is adopted is avoided. Besides, the Micro-LED with an independent structure is grown on the inclined plane of the triangular island, so that the adverse effect of the traditional micromachining technology on the etching damage of the quantum well and the P-type layer can be avoided, the edge effect of each light-emitting unit is effectively inhibited, and the light-emitting efficiency is improved; the light-emitting units are arranged on the basis of close packing, the area of the epitaxial wafer can be effectively utilized to the maximum extent, and economic benefits are maximized.

Description

Technical Field

[0001] The present invention relates to a driving Micro-LED structure and a preparation method thereof, belonging to the fields of GaN-based HEMT, Micro-LED, etc. Background Art

[0002] Micro-LED technology is an emerging display technology with significant advantages, such as high brightness, wide color gamut and excellent contrast. However, the application of this technology also brings new challenges, one of which is the need for additional driving circuits. The core of Micro-LED lies in its tiny light-emitting diode (LED) array, and each pixel is composed of a separate LED. This miniaturized structure allows each pixel to emit light independently, thereby achieving higher display accuracy and a wider color gamut.

[0003] However, this fine control requires that each LED can be driven and adjusted accurately, so a complex driving circuit is needed to support it. Specifically, the driving circuit of the Micro-LED screen needs to meet two main requirements. The first is high-precision current control, because the brightness of each LED needs to be adjusted very accurately to achieve the best display effect. Second, because the pixel density of Micro-LED is very high, the driving circuit must be able to handle a large amount of current and maintain efficient power distribution. These requirements make the driving circuit design complicated and require optimization in integration and heat dissipation design. In addition, the high resolution and high brightness characteristics of Micro-LED technology also put forward higher performance requirements for the driving circuit. In order to maintain the consistency of the screen under different ambient light conditions, the driving circuit must be able to adjust the brightness of each LED in real time to cope with various display needs. This requires not only that the driving circuit has powerful processing power, but also needs to be optimized in terms of power consumption and thermal management to ensure long-term stability and reliability. Summary of the invention

[0004] The present invention aims to use selective epitaxy combined with lateral epitaxy to obtain a naturally formed left-right symmetrical GaN island, and to set up HEMT and Micro-LED structures on both sides of the symmetry, so that the HEMT on one side can directly drive the Micro-LED on the other side, solving the problem that the traditional Micro-LED needs additional drive, and also avoiding the micropores that are the constraints of the current in the traditional selective epitaxy MicroLED structure. Figure 3 As shown, when this structure is working, the carriers flow from the A electrode 107 of the HEMT structure on the left to the lower part 103 of the GaN three-dimensional triangle island and the Al x Ga 1-xThe 2DEG formed between the N layers 105 diffuses into the N-doped strain control layer 109 of the right Micro-LED structure in the upper half 104 of the N-doped GaN three-dimensional triangular island to drive the Micro-LED. In addition, by using the three-dimensional independent island structure, the adverse effects brought by the etching damage of the quantum well and P-type layer in traditional microfabrication technology are avoided from the root, the edge effect of each light-emitting unit is effectively suppressed, and the light-emitting efficiency is improved; arranging the light-emitting units based on close packing can effectively utilize the area of the epitaxial wafer to the greatest extent and maximize the economic benefits. At the same time, the semi-polar AlGaN / GaN heterojunction formed by the lattice symmetry in the present invention has an acute angle between the interface and the polar axis, and the generated 2DEG concentration is smaller than that of the traditional structure and is easier to control. Moreover, the island structure is beneficial to releasing the stress of the epitaxial material, improving the crystal quality of the Micro-LED unit structure with driving, and weakening the influence of defects and polarization on carriers. To improve the crystal quality, the size of the circumscribed circle diameter of the triangular mesa structure in the plane is specified. To reduce the influence of the polarization effect, Al with different components and thicknesses is set x Ga 1-x N layer 105. To solve the problem of the crystal quality of epitaxial growth of GaN caused by the lack of a suitable substrate, an N-doped strain control layer is set, and Al x1 Ga 1-x1 N / GaN / Al x1 Ga 1-x1 N composite layer is obtained to obtain a high-quality quantum well and improve the overall light efficiency of the Micro-LED. To achieve a higher radiative recombination efficiency, an electron blocking layer with a wider bandgap or a highly P-doped hole injection layer is set.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] On the one hand, the present invention provides a Micro-LED structure with driving, characterized in that: the structure includes a non-polar GaN layer 101 with an upward crystal plane, a mask layer 102 containing micropores, the lower half 103 of the GaN three-dimensional triangular island, and the upper half 104 of the N-doped GaN three-dimensional triangular island, which are arranged from left to right and from bottom to top in sequence; wherein, the lower half 103 of the GaN three-dimensional triangular island and the upper half 104 of the N-doped GaN three-dimensional triangular island form an integral triangular mesa structure S, which is obtained by epitaxial growth upward through the micropores of the mask layer 102 and includes two left and right symmetric triangular inclined planes, a triangular side perpendicular to the bottom surface, and a triangular top surface parallel to and geometrically similar to the bottom surface except for the bottom; the structure arranged on the left includes: Al with an Al composition of 0.1 < x < 0.4 x Ga 1-xN layer 105, insulating dielectric layer 106, A electrode 107 below the lower half 103 of the GaN three-dimensional triangular island, and B electrode 108 on the insulating dielectric layer 106 and close to the A electrode 107; wherein Al x Ga 1-x The N layer 105 covers the left slope of the lower part 103 of the GaN three-dimensional triangular island and continues to extend upward, covering the left slope of the upper part 104 of the N-doped GaN three-dimensional triangular island by no less than 30%; the structure arranged on the right side includes: the N-doped strain control layer 109 covering the right side of the entire triangular table structure S, the quantum well layer 1010, the carrier control layer 1011, the P-type In y Ga 1-y N layer 1012, and P type In y Ga 1-y The N layer 1012 has a C electrode 1013 with good ohmic contact.

[0007] Preferably, the mask layer 102 containing the micropore array is a 5-50 nm thick dielectric film plated on the non-polar surface GaN layer 101, wherein the dielectric film is one of SiO2, SiN or hBN, and the micropore array is etched from top to bottom by process technology, and the underlying non-polar surface GaN layer 101 is exposed in the micropores; the diameter of the micropores is between 0.5 and 5 μm, and they are arranged in a close-packed form with the centers of the micropores, and the center distance between any micropore and the six adjacent micropores is equal, and can be adjusted according to actual needs.

[0008] Preferably, the non-polar GaN layer 101 and the upward crystal plane of the triangular table structure S are both (11-20) planes, and the crystal planes of the left and right inclined planes are both {1-101} or {1-102} crystal plane families. Since the crystal plane families {1-101} or {1-102} are lower potential energy surfaces, a regular triangular island can be formed, and the layer structure above can grow regularly and controllably. In addition, the non-polar GaN layer 101 and the upward crystal plane of the triangular table structure S can also be (1-100) planes at the same time, and the crystal planes of the left and right inclined planes are both {20-21} crystal plane families. In common, the triangular side faces perpendicular to the bottom face are both (000-1) planes.

[0009] Preferably, when the micropore diameter of the mask layer 102 is not greater than 1.5 μm, the in-plane circumscribed circle diameter of the triangular mesa structure S is adjusted between 5 and 20 μm as needed. Because when the micropores are small, regular islands are easily formed, and at this time, the size of the islands can be controlled as needed; when the micropore diameter of the mask layer 102 is greater than 1.5 μm, the in-plane circumscribed circle diameter of the triangular mesa structure S is 3 to 4 times the micropore diameter, but not exceeding 15 μm at most. Because when the micropores are large, the islands are prone to be irregular, so the size of the islands is limited. Setting the island structure composed of the lower half 103 of the GaN three-dimensional triangular island and the upper half 104 of the N-doped GaN three-dimensional triangular island is beneficial to releasing the stress of the epitaxial material, improving the crystal quality of the Micro-LED unit structure with a driver, and weakening the influence of defects and polarization on carriers.

[0010] Preferably, when the upward crystal plane of the GaN layer 101 is the (11-20) plane and the left and right inclined planes are the {1-101} crystal plane family, Al x Ga 1-x The Al composition of the N layer 105 is 0.15 < x < 0.4, and the thickness is: 2 / x ± 5 nm. Since the angle between the (1-101) plane and the (0002) plane is about 61.9°, the polarization effect is relatively low, so a higher Al composition or thickness is required; when the upward crystal plane of the non-polar GaN layer 101 is the (11-20) plane and the left and right inclined planes are the {1-102} crystal plane family, Al x Ga 1-x The Al composition of the N layer 105 is 0.1 < x < 0.3, and the thickness is: 1.5 / x ± 5 nm. Since the angle between the (1-102) plane and the (0002) plane is about 61.9°, the polarization effect is relatively low, so a higher Al composition or thickness is required; when the upward crystal plane of the non-polar GaN layer 101 is the (1-100) plane and the left and right inclined planes are the {20-21} crystal plane family, Al x Ga 1-x The Al composition of the N layer 105 is 0.15 < x < 0.4, and the thickness is: 3 / x ± 5 nm. Since the angle between the (20-21) plane and the (0002) plane is about 75°, the polarization effect is very small, so a higher Al composition or a thicker thickness is required.

[0011] Preferably, the A electrode 107 is at the bottom of the left inclined plane of the triangular mesa structure S and contacts the Al x Ga 1-x N layer 105, and does not contact the lower half 103 of the GaN three-dimensional triangular island; the insulating dielectric layer 106 covers the Al x Ga 1-x N layer 105 from one side of the A electrode 107, and the coverage rate > 30%; the B electrode 108 contacts the insulating dielectric layer 106 and is close to the A electrode 107 side.

[0012] Preferably, the N-doped strain control layer 109 covers the entire right side slope of the triangular table structure S, and its structure is 1 to 3 cycles of Al x1 Ga 1-x1 N / GaN / Al x1 Ga 1-x1 N composite layer, in which Al x1 Ga 1-x1 The thickness of N is less than 3nm, and x1<0.15. The introduction of lower-component AlGaN can compensate for a certain amount of in-plane stress in the c direction.

[0013] Preferably, when the light emission wavelengths of the quantum well layer 1010 are red, green, and blue, the number of quantum well pairs is 1 to 2 pairs, 2 to 4 pairs, and 3 to 5 pairs, respectively; the layer structure of the quantum well is In x2 Ga 1-x2 N / GaN / Al x3 Ga 1-x3 N / GaN, where x3 = 2.5 x2 ± 0.05, and In x2 Ga 1-x2 The thickness of N is 2 to 4 nm, and the two layers of GaN and Al x3 Ga 1-x3 The total thickness of N does not exceed 6nm. x2 Ga 1-x2 The lattice mismatch between N and GaN in the c direction is △1=0.09797×x2, and the lattice mismatch between GaN and Al x3 Ga 1-x3 The lattice mismatch value of N in the c direction is △2 = -0.03915×x3; by adjusting the molar components x2 and x3, Al x3 Ga 1-x3 N and In x2 Ga 1- x2 The lattice mismatch value of N in the c direction is equivalent to that of GaN (that is, it satisfies △1=-△2), that is, it satisfies x3=2.5×x2±0.05, realizing stress compensation between layers, and then obtaining high-quality quantum wells, thereby improving the overall Micro-LED lighting efficiency.

[0014] Preferably, the carrier regulation layer 1011 is one of an electron blocking layer and a hole injection layer; wherein the electron blocking layer is an Al2O3 layer having 2 to 8 cycles and a single cycle thickness of less than 8 nm. y1 Ga 1-y1 N / GaN superlattice, where the molar composition y1 is between 0.1 and 0.6, and Al y1 Ga 1-y1There is a negative correlation with the thickness of N; the hole injection layer is P-doped Al with an overall thickness of less than 30 nm y2 Ga 1-y2 N / In y3 Ga 1-y3 N / GaN superlattice, with the doping concentration of Mg element being 5×10 17 cm -3 ~1×10 19 cm -3 Between them, the hole concentration is not higher than 1×10 18 cm -3 . By setting an electron blocking layer with a wider bandgap or a highly P-doped hole injection layer, the carriers in the active region, i.e., the multiple quantum wells, are restricted, thereby increasing the overlap of the hole and electron wave functions in the multiple quantum wells and achieving a higher radiative recombination efficiency.

[0015] Preferably, the thickness of the P-type In y Ga 1-y N layer 1012 is between 50 and 200 nm, and the molar component y is 0 to 0.15. When y = 0, it is GaN; the doping concentration of Mg element is 2×10 19 cm -3 ~5×10 19 cm -3 Between them, the hole concentration is not less than 1×10 18 cm -3 ; among them, in the 5 - 30 nm thickness region on the upper surface of the P-type In y Ga 1-y N layer 107, the doping concentration of Mg element is not less than 1×10 20 cm -3 , and its hole concentration is not less than 5×10 18 cm -3 .

[0016] On the other hand, the present invention provides a preparation method for the Micro-LED structure with driving. This structure includes a non-polar GaN layer 101 with an upward crystal plane, a mask layer 102 containing micropores, the lower half of a GaN three-dimensional triangular island 103, and the upper half of an N-doped GaN three-dimensional triangular island 104, which are arranged in sequence from left to right and from bottom to top; among them, the lower half of the GaN three-dimensional triangular island 103 and the upper half of the N-doped GaN three-dimensional triangular island 104 form an integral triangular mesa structure S, which is obtained by epitaxial growth upward from the micropores of the mask layer 102 and includes two left-right symmetric triangular inclined planes, a triangular side perpendicular to the bottom surface, and a triangular top surface parallel to and geometrically similar to the bottom surface except at the bottom; the structure arranged on the left includes: Al with an Al component of 0.1 < x < 0.4 x Ga 1-xN layer 105, insulating dielectric layer 106, A electrode 107 below the lower half 103 of the GaN three-dimensional triangular island, and B electrode 108 on the insulating dielectric layer 106 and close to the A electrode 107; wherein Al x Ga 1-x The N layer 105 covers the left slope of the lower part 103 of the GaN three-dimensional triangular island and continues to extend upward, covering the left slope of the upper part 104 of the N-doped GaN three-dimensional triangular island by no less than 30%; the structure arranged on the right side includes: the N-doped strain control layer 109 covering the right side of the entire triangular table structure S, the quantum well layer 1010, the carrier control layer 1011, the P-type In y Ga 1-y N layer 1012, and P type In y Ga 1-y The N layer 1012 has a C electrode 1013 with good ohmic contact. The method for preparing the driving Micro-LED structure includes the following steps: a) preparing a non-polar GaN template as the non-polar GaN layer 101, or epitaxially growing a non-polar GaN film on a sapphire, Si or SiC substrate as the non-polar GaN layer 101; b) preparing a dielectric film on the non-polar GaN layer 101, and using micromachining technology to process a microporous structure on the dielectric layer to expose the non-polar GaN layer 101 below; c) using the selective epitaxial growth technology to perform selective epitaxy using the micropores, and then controlling the temperature of the epitaxial growth, The V / III ratio, reaction chamber pressure, carrier gas, and reactant source flow rates achieve lateral epitaxy to form GaN three-dimensional triangular islands; d) during the epitaxial growth process, the supply of Ga source is stopped, the flow rate of N source is reduced, and the GaN three-dimensional triangular island is subjected to in-situ annealing treatment to decompose the GaN three-dimensional triangular island in-situ to form the lower half 103 of the GaN three-dimensional triangular island; e) continuing epitaxial growth, growing an N-doped GaN three-dimensional triangular island upper part 104 on the GaN three-dimensional triangular island lower part 103, to form an overall triangular table structure; f) Combined with micromachining technology, a SiO2 or SiN dielectric layer is prepared on the left side of the GaN three-dimensional triangular island, and then an N-doped strain control layer 109, a sequentially covered quantum well layer 1010, a carrier control layer 1011 and a P-type In layer are sequentially completed on the right side of the GaN three-dimensional triangular island using epitaxial growth technology. y Ga 1-y Epitaxial growth of N layer 1012; g) Reactive ion etching technology is used to remove the SiO2 or The SiN dielectric layer is etched away to expose the left slope of the GaN three-dimensional triangular island; h) Using micromachining technology, Al is sequentially prepared on the left slope of the GaN three-dimensional triangle island. x Ga 1-x N layer 105 and insulating dielectric layer 106; i) Using metal plating technology combined with micro-machining technology, the A electrode 107, the B electrode 108 and the C electrode 1013 are prepared at the corresponding positions to complete the preparation of the Micro-LED structure containing the driver.

[0017] Beneficial effects:

[0018] The structure provided by the present invention is a GaN island with a three-dimensional structure obtained by selective epitaxy combined with lateral epitaxy. The GaN island naturally forms a bilaterally symmetrical structure due to its crystal properties. HEMT and Micro-LED structures are respectively arranged on both sides. The HEMT on one side can be directly used to drive the Micro-LED on the other side, solving the problem that traditional Micro-LEDs require additional driving, and also avoiding the micropores that constrain the current in the traditional selective epitaxial MicroLED structure.

[0019] It is stipulated that when the micropore diameter of the mask layer 102 is no more than 1.5 μm, the in-plane circumscribed circle diameter of the triangular mesa structure S can be adjusted between 5 and 20 μm as needed. Because when the micropores are small, regular islands are likely to be formed, and at this time, the size of the islands can be controlled as needed; when the micropore diameter of the mask layer 102 is greater than 1.5 μm, the in-plane circumscribed circle diameter of the triangular mesa structure S is 3 to 4 times the micropore diameter, but not exceeding 15 μm at most, because when the micropores are large, the islands are likely to be irregular, so the size of the islands is limited. And the island structure is beneficial to releasing the stress of the epitaxial material, improving the crystal quality of the Micro-LED unit structure with driving, and weakening the influence of defects and polarization on carriers. When the upward crystal plane of the GaN three-dimensional triangular island 103 is the (11-20) plane and the left and right two inclined planes are the {1-101} crystal plane family, since the angle between (1-101) and (0002) is 61.9°, the polarization effect is relatively low, so a higher Al component (0.15 < x < 0.4) or thickness (2 / x ± 5 nm) is required; when the upward crystal plane of the GaN three-dimensional triangular island 103 is the (11-20) plane and the left and right two inclined planes are the {1-102} crystal plane family, since the angle between (1-102) and (0002) is 43°, the polarization effect is acceptable, so a lower Al component (0.1 < x < 0.3) or thickness (1.5 / x ± 5 nm) is required; when the upward crystal plane of the GaN three-dimensional triangular island 103 is the (1-100) plane and the left and right two inclined planes are the {20-21} crystal plane family, since the angle between (20-21) and (0002) is 75°, the polarization effect is very small, so a higher Al component (0.15 < x < 0.4) or a thicker thickness (3 / x ± 5 nm) is required. By adjusting the Al x Ga 1-x N layer 104, the influence of the polarization effect can be reduced, the crystal quality can be improved, and the stability of the HEMT structure can be enhanced.

[0020] At the same time, the present invention utilizes the semi-polar plane AlGaN / GaN heterojunction formed by lattice symmetry. The angle between the interface and the polar axis is an acute angle, and the generated 2DEG concentration is smaller than that of the traditional structure and is easier to control. Growing Micro-LEDs with independent structures on the inclined planes of the triangular islands can avoid the adverse effects brought by the etching damage of the quantum well and P-type layer by traditional microfabrication techniques, effectively suppress the edge effect of each light-emitting unit, and improve the light-emitting efficiency; arranging the light-emitting units based on close packing can effectively utilize the area of the epitaxial wafer to the greatest extent and maximize the economic benefits.

[0021] To relieve In x Ga 1-xThe N quantum well has a series of adverse effects (such as defects caused by stress release) caused by the large lattice mismatch with GaN. The present invention sets a strain control layer and a specially designed quantum well structure before growing the quantum well, and introduces an AlGaN layer with a specific molar composition to produce a strain opposite to that of InGaN to offset the strain of InGaN. The principle is as follows: First, according to the formula

[0022] Calculate the lattice mismatch value, where △ is the lattice mismatch value, c GaN The c-axis lattice constant of GaN is 5.185 angstroms, c n Al x1 Ga 1-x1 N and In x Ga 1-x The c-axis lattice constant of N. n The calculation formula is: c n =b×c AlN或InN +(1-b)c GaN

[0023] Where b is x2 or x3, c AlN或InN is the c-axis lattice constant of AlN or InN, which are 4.982 angstroms and 5.693 angstroms respectively. Substituting the corresponding values ​​into InN gives x2 Ga 1-x2 The lattice mismatch value between N and GaN in the c direction is △1 = 0.09797 × x2; Al x3 Ga 1-x3 The lattice mismatch value between N and GaN in the c direction is △2 = -0.03915 × x3. By adjusting the molar composition x2 and x3, In x2 Ga 1-x2 N and Al x3 Ga 1-x3 The lattice mismatch value of N in the c direction is equivalent to that of GaN (that is, it satisfies △1=-△2), that is, it satisfies x3=2.5×x2±0.05. At this time, AlGaN will produce a strain in the opposite direction and with a similar value to InGaN to offset the strain of InGaN and suppress defects in InGaN due to excessive strain, thereby obtaining high-quality quantum wells and improving the overall Micro-LED lighting efficiency.

[0024] An electron blocking layer or a highly P-doped hole injection layer with a wider bandgap width is set to limit the carriers in the active area, namely the multiple quantum wells, so that the overlap of the hole and electron wave functions in the multiple quantum wells is increased, and a higher radiation recombination efficiency is achieved, further solving the problem of the decrease in internal quantum efficiency as the injection current density increases. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic cross-sectional view of a Micro-LED structure including a driver provided by the present invention.

[0026] Figure 2 A schematic top view of a Micro-LED structure including a driver provided by the present invention.

[0027] Figure 3 A schematic diagram of carrier flow direction of a Micro-LED structure including a driver provided by the present invention.

[0028] Among them, 101 is a GaN layer with a non-polar surface facing upward; 102 is a mask layer containing micropores; 103 is the lower half of the GaN three-dimensional triangular island; 104 is the upper half of the N-doped GaN three-dimensional triangular island; 105 is the Al x Ga 1-x N layer; 106 is an insulating dielectric layer; 107 is an A electrode; 108 is a B electrode; 109 is an N-doped strain control layer; 1010 is a quantum well layer; 1011 is a carrier control layer; 1012 is a P-type In y Ga 1-y N layer; 1013 is the C electrode. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0031] Embodiment 1:

[0032] A cross-sectional schematic diagram of a Micro-LED structure including a driver provided in Example 1 of the present invention is shown in FIG. Figure 1 As shown, the top view diagram is as follows Figure 2As shown, the driver-containing Micro-LED structure includes a non-polar GaN layer 101 with an upward crystal plane of (11-20) plane, a mask layer 102 containing micropores, a lower half of a GaN three-dimensional triangular island 103, and an upper half of an N-doped GaN three-dimensional triangular island 104, which are arranged from left to right and from bottom to top in sequence; wherein the lower half of the GaN three-dimensional triangular island 103 and the upper half of the N-doped GaN three-dimensional triangular island 104 form an integral triangular table structure S, which is obtained by upward epitaxial growth in the micropores of the mask layer 102, and includes two left-right symmetrical triangular inclined surfaces, a triangular side surface perpendicular to the bottom surface, and a triangular top surface parallel to the bottom surface and geometrically similar; the structure arranged on the left side includes: Al with an Al component x=0.15 x Ga 1-x N layer 105, insulating dielectric layer 106, A electrode 107 below the lower half 103 of the GaN three-dimensional triangular island, and B electrode 108 on the insulating dielectric layer 106 and close to the A electrode 107; wherein Al x Ga 1-x The N layer 105 covers the left slope of the lower part 103 of the GaN three-dimensional triangular island and continues to extend upward, covering 50% of the left slope of the upper part 104 of the N-doped GaN three-dimensional triangular island; the structure arranged on the right side includes: the N-doped strain control layer 109 covering the right side of the entire triangular table structure S, the quantum well layer 1010, the carrier control layer 1011, the P-type In y Ga 1-y N layer 1012, and P type In y Ga 1-y The N layer 1012 has a C electrode 1013 with good ohmic contact.

[0033] The non-polar GaN layer 101 and the upward crystal plane of the triangular table structure S are both (11-20) planes, wherein the diameter of the circumscribed circle of the triangular table structure S within the plane is 10 μm.

[0034] A 30 nm thick SiO2 dielectric film is plated on the N-type GaN layer 101 as a mask layer 102, and a microhole array is etched from top to bottom through process technology, exposing the underlying GaN layer 101 in the microholes. The diameter of the microholes in the mask layer 102 is 1 μm.

[0035] Al x Ga 1-x The N layer 105 covers the left side of the triangular mesa structure S, wherein the Al composition x=0.15 and the thickness is 12 nm.

[0036] The A electrode 107 is at the bottom of the triangular table structure S, and the insulating dielectric layer 106 covers the Al x Ga 1-xThe N layer 105 has a coverage rate of 50%, and the B electrode 108 is in contact with the insulating dielectric layer 106 and is close to the A electrode 107 side.

[0037] The N-doped strain control layer 109 covers the entire right slope of the triangular table structure S, and its structure is a three-period bottom-up Al x1 Ga 1-x1 N / GaN / Al x1 Ga 1-x1 N composite layer, in which Al x1 Ga 1-x1 The thickness of N is 2 nm and the molar composition x1=0.1.

[0038] When the wavelengths of the quantum well layer 1010 light emission are red, green, and blue, respectively, the number of quantum well pairs is 2 pairs, 3 pairs, and 2 pairs, respectively; the layer structure of the quantum well is In x2 Ga 1-x2 N / GaN / Al x3 Ga 1-x3 N / GaN, where the molar composition x2=0.2, x3=0.5, and In x2 Ga 1-x2 The thickness of N is 2nm, two layers of GaN and Al x3 Ga 1-x3 The total thickness of N is 5 nm.

[0039] The carrier regulation layer 1011 is an electron blocking layer, wherein the electron blocking layer is Al2O3 with a thickness of 5 nm and a period of 4. y1 Ga 1-y1 N / GaN superlattice with molar composition y1=0.5.

[0040] P-type In y Ga 1-y The thickness of the N layer 1012 is 100 nm, the molar composition y=0.1, and the Mg element doping concentration is 4×10 19 cm -3 , and its hole concentration is 2×10 18 cm -3 ; Among them, P type In y Ga 1-y In the 30 nm thick region on the upper surface of the N layer 107, the doping concentration of Mg element is 2×10 20 cm -3 , and its hole concentration is 6×10 18 cm -3 .

[0041] A method for preparing a Micro-LED structure including a driver provided in Example 1 of the present invention comprises the following steps: a) preparing a non-polar (11-20)-plane GaN template as the non-polar GaN layer 101, wherein the upward crystal planes of the non-polar GaN layer 101 and the triangular table structure S are both (11-20) planes, and the left and right inclined planes are {1-102} crystal plane family; b) preparing a dielectric film on the non-polar GaN layer 101, and using micromachining technology to process a micropore structure on the dielectric layer, the micropore diameter is 1 μm, exposing the non-polar GaN layer 101 below; c) using the selective epitaxial growth technology to perform selective epitaxy using the micropores, and then achieving lateral epitaxy by controlling the epitaxial growth temperature, V / III ratio, reaction chamber pressure, carrier gas, and reactant source flow rate to form a GaN three-dimensional triangular island; d) during the epitaxial growth process, stopping the supply of Ga source, reducing the flow rate of N source, and performing in-situ annealing on the GaN three-dimensional triangular island to decompose the GaN three-dimensional triangular island in-situ to form the lower half 103 of the GaN three-dimensional triangular island; e) continuing the epitaxial growth, in the Ga An N-doped GaN three-dimensional triangular island upper part 104 is grown on the N three-dimensional triangular island lower part 103 to form an integral triangular table structure S, the diameter of the circumscribed circle of this structure in the plane is 10nm; f) In combination with micromachining technology, a SiO2 dielectric layer is prepared on the left inclined surface of the GaN three-dimensional triangular island, and then an epitaxial growth technology is used to sequentially complete the N-doped strain control layer 109, the quantum well layer 1010, the carrier control layer 1011 and the P-type In layer on the right inclined surface of the GaN three-dimensional triangular island. y Ga 1-y Epitaxial growth of N layer 1012; g) using reactive ion etching technology to etch away the SiO2 dielectric layer prepared on the left side slope of the GaN three-dimensional triangular island in a chlorine-free environment to expose the left side slope of the GaN three-dimensional triangular island; h) Using micromachining technology, Al with Al component x = 0.15 and thickness of 12 nm was prepared on the left slope of the GaN triangle island. x Ga 1-x The N layer 105 and the A electrode 107 cover the Al x Ga 1-x N layer 105, an insulating dielectric layer 106 with a coverage rate of 50%; i) Using metal plating technology combined with micro-machining technology, the A electrode 107, the B electrode 108 and the C electrode 1013 are prepared at the corresponding positions to complete the preparation of the Micro-LED structure containing the driver.

Claims

1. A Micro-LED structure including a driver, characterized in that: The structure includes a GaN layer 101 with a non-polar surface as an upward crystal plane, a mask layer 102 containing micropores, a lower half 103 of a GaN three-dimensional triangular island, and an upper half 104 of an N-doped GaN three-dimensional triangular island, which are arranged successively from left to right and from bottom to top; among them, the lower half 103 of the GaN three-dimensional triangular island and the upper half 104 of the N-doped GaN three-dimensional triangular island form an integral triangular mesa structure S, which is obtained by epitaxial growth upward through the micropores of the mask layer 102, and includes two left-right symmetric triangular inclined planes, a triangular side perpendicular to the bottom surface, and a triangular top surface parallel to and geometrically similar to the bottom surface except at the bottom; the structure arranged on the left side includes: an Al x Ga 1-x N layer 105, an insulating dielectric layer 106, an A electrode 107 below the lower half 103 of the GaN three-dimensional triangular island, and a B electrode 108 on the insulating dielectric layer 106 and close to the A electrode 107; where Al x Ga 1-x N layer 105 covers the left inclined plane of the lower half 103 of the GaN three-dimensional triangular island and continues to extend upward, covering no less than 30% of the left inclined plane of the upper half 104 of the N-doped GaN three-dimensional triangular island; the structure arranged on the right side includes: an N-doped strain control layer 109 covering the entire right side of the triangular mesa structure S, a quantum well layer 1010, a carrier control layer 1011, and a P-type In y Ga 1-y N layer 1012, and a C electrode 1013 having a good ohmic contact with the P-type In y Ga 1-y N layer 1012.

2. A Micro-LED structure with driver according to claim 1, characterized in that: The mask layer 102 containing the microhole array is formed by etching a 5-50 nm thick SiO2, SiN or hBN dielectric film on the N-type GaN layer 101 from top to bottom through a process technology, and the N-type GaN layer 101 below is exposed in the microholes; The diameter of the micropores is between 0.5 and 5 μm, and the micropores are arranged in a densely packed form. The center distances of any micropore and the six adjacent micropores are equal and can be adjusted according to actual needs.

3. The Micro-LED structure with driver according to claim 1, characterized in that: The upward crystal planes of the non-polar GaN layer 101 and the triangular table structure S are both (11-20) planes, and at this time, the crystal planes of the left and right inclined planes are both one of the {1-101} or {1-102} crystal plane families; in addition, the upward crystal planes of the non-polar GaN layer 101 and the triangular table structure S can also be (1-100) planes at the same time, and at this time, the crystal planes of the left and right inclined planes are both {20-21} crystal plane families; the triangular side surfaces perpendicular to the bottom surface are both (000-1) planes; when the micropore diameter of the mask layer 102 is not greater than 1.5μm, the diameter of the circumscribed circle of the triangular table structure S within the plane is adjusted between 5 and 20μm as needed; when the micropore diameter of the mask layer 102 is greater than 1.5μm, the diameter of the circumscribed circle of the triangular table structure S within the plane is 3 to 4 times the diameter of the micropore, but the maximum does not exceed 15μm.

4. The Micro-LED structure with driver according to claim 1, characterized in that: When the crystal plane of the non-polar surface GaN layer 101 facing upward is the (11-20) plane and the two left and right inclined planes are the {1-101} crystal plane family, Al x Ga 1-x The Al composition of the N layer 105 is 0.15 < x < 0.4, and the thickness is: 2 / x ± 5 nm; when the crystal plane of the non-polar surface GaN layer 101 facing upward is the (11-20) plane and the two left and right inclined planes are {1-102}, Al x Ga 1-x The Al composition of the N layer 105 is 0.1 < x < 0.3, and the thickness is: 1.5 / x ± 5 nm; when the crystal plane of the non-polar surface GaN layer 101 facing upward is the (1-100) plane and the two left and right inclined planes are the {20-21} crystal plane family, Al x Ga 1-x The Al composition of the N layer 105 is 0.15 < x < 0.4, and the thickness is: 3 / x ± 5 nm.

5. The Micro-LED structure with driver according to claim 1, characterized in that: The A electrode 107 is at the bottom of the left slope of the triangular table structure S and is connected to the Al x Ga 1-x The N layer 105 is in contact with the triangular table structure S, and the insulating dielectric layer 106 covers the Al electrode 107 from one side. x Ga 1-x N layer 105, coverage>30%; B electrode 108 is in contact with the insulating dielectric layer 106, close to the A electrode 107 side.

6. The Micro-LED structure with driver according to claim 1, characterized in that: The N-doped strain control layer 109 covers the entire right slope of the triangular table structure S, and its structure is 1 to 3 cycles of Al x1 Ga 1-x1 N / GaN / Al x1 Ga 1-x1 N composite layer, in which Al x1 Ga 1-x1 The thickness of N is less than 3 nm, and x1<0.

15.

7. The Micro-LED structure with driver according to claim 1, characterized in that: When the wavelengths of light emitted by the quantum well layer 1010 are red, green, and blue, respectively, the number of quantum well pairs is 1 to 2 pairs, 2 to 4 pairs, and 3 to 5 pairs, respectively; the layer structure of the quantum well is In x2 Ga 1-x2 N / GaN / Al x3 Ga 1-x3 N / GaN, where x3 = 2.5 x2 ± 0.05, and In x2 Ga 1-x2 The thickness of N is 2 to 4 nm, and the two layers of GaN and Al x3 Ga 1-x3 The total thickness of N does not exceed 6 nm.

8. The Micro-LED structure with driver according to claim 1, characterized in that: The carrier regulation layer 1011 is one of an electron blocking layer and a hole injection layer; wherein the electron blocking layer is an Al2O3 layer with 2 to 8 cycles and a single cycle thickness of less than 8 nm. y1 Ga 1-y1 N / GaN superlattice, where the molar composition y1 is between 0.1 and 0.6, and Al y1 Ga 1-y1 The hole injection layer is P-doped with an overall thickness of less than 30nm Al y2 Ga 1-y2 N / In y3 Ga 1-y3 N / GaN superlattice, Mg doping concentration is 5×10 17 cm -3 ~1×10 19 cm -3 The hole concentration is not higher than 1×10 18 cm -3 .

9. The Micro-LED structure with driver according to claim 1, characterized in that: P-type In y Ga 1-y The thickness of the N layer 1012 is between 50 and 200 nm, and the molar composition y is between 0 and 0.

15. When y=0, it is GaN. The Mg element doping concentration is 2×10 19 cm -3 ~5×10 19 cm -3 The hole concentration is not less than 1×10 18 cm -3 ; Among them, P type In y Ga 1-y In the 5-30 nm thickness region on the upper surface of the N layer 107, the doping concentration of the Mg element is not less than 1×10 20 cm -3 , the hole concentration is not less than 5×10 18 cm -3 .

10. A method for preparing a Micro-LED structure with a driver, the structure comprising a GaN layer 101 with a non-polar surface facing upward, a mask layer 102 containing micropores, a lower half of a GaN three-dimensional triangular island 103, and an upper half of an N-doped GaN three-dimensional triangular island 104, which are arranged in sequence from left to right and from bottom to top; wherein: The lower part 103 of the GaN three-dimensional triangular island and the upper part 104 of the N-doped GaN three-dimensional triangular island form an integral triangular table structure S, which is obtained by epitaxial growth upward from the microholes in the mask layer 102, and includes two bilaterally symmetrical triangular inclined surfaces, a triangular side surface perpendicular to the bottom surface, and a triangular top surface parallel to the bottom surface and geometrically similar; The structure disposed on the left side includes: AlGaN layer 105 with an Al composition of 0.1 < x < 0.4, an insulating dielectric layer 106, an A electrode 107 under the lower half 103 of the GaN three-dimensional triangular island, and a B electrode 108 on the insulating dielectric layer 106 and close to the A electrode 107; where the AlGaN layer 105 covers the left inclined surface of the lower half 103 of the GaN three-dimensional triangular island and continues to extend upward, covering no less than 30% of the left inclined surface of the upper half 104 of the N-doped GaN three-dimensional triangular island; x Ga 1-x N layer 105, an insulating dielectric layer 106, and an A electrode 107 under the lower half 103 of the GaN three-dimensional triangular island, and a B electrode 108 on the insulating dielectric layer 106 and close to the A electrode 107; where the Al x Ga 1-x N layer 105 covers the left inclined surface of the lower half 103 of the GaN three-dimensional triangular island and continues to extend upward, covering no less than 30% of the left inclined surface of the upper half 104 of the N-doped GaN three-dimensional triangular island; The structure disposed on the right side includes: an N-doped strain control layer 109 covering the entire right side of the triangular mesa structure S, a quantum well layer 1010, a carrier control layer 1011, a P-type In y Ga 1-y N layer 1012, and a C electrode 1013 having a good ohmic contact with the P-type In y Ga 1-y N layer 1012. The preparation method of this Micro-LED structure with driving includes the following steps: a) preparing a non-polar GaN template as the non-polar GaN layer 101, or epitaxially growing a non-polar GaN film on a sapphire, Si or SiC substrate as the non-polar GaN layer 101; b) preparing a dielectric film on the non-polar GaN layer 101, and using micromachining technology to process a microporous structure on the dielectric layer to expose the non-polar GaN layer 101 below; c) using the selective epitaxial growth technology to perform selective epitaxy using the micropores, and then achieving lateral epitaxy by controlling the epitaxial growth temperature, V / III ratio, reaction chamber pressure, carrier gas, and reactant source flow rates to form GaN three-dimensional triangular islands; d) during the epitaxial growth process, the supply of Ga source is stopped, the flow rate of N source is reduced, and the GaN three-dimensional triangular island is subjected to in-situ annealing treatment to decompose the GaN three-dimensional triangular island in-situ to form the lower half 103 of the GaN three-dimensional triangular island; e) continuing epitaxial growth, growing an N-doped GaN three-dimensional triangular island upper part 104 on the GaN three-dimensional triangular island lower part 103, to form an overall triangular table structure; f) Combined with micromachining technology, a SiO2 or SiN dielectric layer is prepared on the left side of the GaN three-dimensional triangular island, and then an N-doped strain control layer 109, a sequentially covered quantum well layer 1010, a carrier control layer 1011 and a P-type In layer are sequentially completed on the right side of the GaN three-dimensional triangular island using epitaxial growth technology. y Ga 1-y Epitaxial growth of N layer 1012; g) using reactive ion etching technology to etch away the SiO2 or SiN dielectric layer prepared on the left side slope of the GaN three-dimensional triangular island in a chlorine-free environment to expose the left side slope of the GaN three-dimensional triangular island; h) Using micromachining technology, Al is sequentially prepared on the left slope of the GaN three-dimensional triangle island. x Ga 1-x N layer 105 and insulating dielectric layer 106; i) Using metal plating technology combined with micro-machining technology, the A electrode 107, the B electrode 108 and the C electrode 1013 are prepared at the corresponding positions to complete the preparation of the Micro-LED structure containing the driver.

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