A micro-LED chip for AR / VR full-color display, a micro-LED display panel, and a preparation method thereof

Abstract

The present invention relates to a micro-LED chip for AR / VR full-color display, a micro-LED display panel, and a preparation method thereof, and relates to the field of semiconductor display technology. In the preparation method of the micro-LED chip for AR / VR full-color display of the present application, a plurality of first grooves are formed in a first region of a growth substrate, and a plurality of second grooves are formed in a second region of the growth substrate, and the number of the second grooves is set to be greater than the number of the first grooves, and then a first dielectric block is formed in the first groove and a second dielectric block is formed in the second groove, and then a buffer layer and an epitaxial functional layer are formed. By setting the first groove and the second groove, and setting the first dielectric block and the second dielectric block in the first groove and the second groove respectively, the growth substrate is easily dissociated in the subsequent process, thereby improving the preparation yield of the micro-LED chip.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor light-emitting technology, and specifically to a micro-LED chip for AR / VR full-color display, a micro-LED display panel, and a preparation method thereof. Background Art

[0002] With the rapid development of AR / VR technology, users' demands for a higher visual experience are increasingly demanding, and traditional display technologies are no longer able to meet these needs. As a next-generation display technology, Micro-LED, with its high brightness, high contrast, high color saturation, and long life, has become a key choice for full-color displays in AR / VR. In AR / VR devices, Micro-LED full-color display panels can deliver a more realistic virtual world experience. Using full-color perspective technology, the camera captures real-time images and synthesizes the virtual and real worlds to present a multi-color display. This technology not only solves the problem of field of view obstruction in VR devices but also greatly expands user activities, allowing users to move freely in a wider range of spaces and enjoy a more immersive experience. Micro-LED full-color display panels, with their superior performance advantages, are becoming a key display technology in the AR / VR field. Improving the manufacturing process of Micro-LED display panels to promote their application in AR / VR is a matter of widespread concern in the industry. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a micro LED chip, a micro LED display panel and a preparation method thereof for AR / VR full-color display.

[0004] To achieve the above objectives, the present invention proposes a method for preparing a micro LED chip for AR / VR full-color display, the preparation method comprising the following steps:

[0005] A substrate is provided. The substrate includes a first region and a second region. The first region is a middle region of the substrate, and the second region is a peripheral region of the substrate. The second region surrounds the first region.

[0006] A plurality of first grooves are formed in the first region, and a plurality of second grooves are formed in the second region, wherein the number of the second grooves is greater than the number of the first grooves.

[0007] A dielectric material is deposited in the plurality of first grooves and the plurality of second grooves to form a first dielectric block in the first grooves and a second dielectric block in the second grooves.

[0008] Then, a buffer layer is formed on the substrate, and the buffer layer is planarized.

[0009] Then, an epitaxial functional layer is epitaxially grown on the substrate.

[0010] Then, a plurality of first electrodes and a plurality of second electrodes are formed on the epitaxial functional layer.

[0011] A temporary carrier is provided, and the substrate is placed on the temporary carrier with the epitaxial functional layer facing the temporary carrier.

[0012] Then, the substrate is subjected to a dissociation process to remove the substrate;

[0013] The epitaxial functional layer is then cut to form a plurality of micro LED chips.

[0014] As a preferred technical solution, the area of the first region is the same as the area of the second region, and the substrate is a sapphire substrate.

[0015] As a preferred technical solution, the first groove and the second groove are formed by a wet etching process or a dry etching process, and the depth of the first groove is greater than the depth of the second groove.

[0016] As a preferred technical solution, the material of the first dielectric block and the second dielectric block includes one of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, hafnium oxide, and silicon oxynitride, and the preparation process of the first dielectric block and the second dielectric block is chemical vapor deposition process, atomic layer deposition process or magnetron sputtering process.

[0017] As a preferred technical solution, the thickness of the first dielectric block is smaller than the depth of the first groove, and the thickness of the second dielectric block is smaller than the depth of the second groove.

[0018] As a preferred technical solution, during the process of forming the buffer layer on the substrate, a portion of the buffer layer is embedded in the first groove and the second groove.

[0019] As a preferred technical solution, before epitaxially growing the epitaxial functional layer on the substrate, a transition layer is formed on the buffer layer after the planarization treatment.

[0020] The present invention also proposes a micro LED chip for AR / VR full-color display, which is manufactured using the above-mentioned method for preparing the micro LED chip for AR / VR full-color display.

[0021] The present invention also proposes a method for preparing a micro-LED display panel for AR / VR full-color display, which comprises the following steps: providing a driving substrate, providing the above-mentioned micro-LED chip for AR / VR full-color display, and transferring the micro-LED chip to the driving substrate to form a micro-LED display panel for AR / VR full-color display.

[0022] The present invention also proposes a micro-LED display panel for AR / VR full-color display, which is manufactured using the above-mentioned method for preparing the micro-LED display panel for AR / VR full-color display.

[0023] The beneficial effects of the present invention are:

[0024] In the method for preparing a micro-LED chip for AR / VR full-color display of the present application, a plurality of first grooves are formed in a first region of a growth substrate, and a plurality of second grooves are formed in a second region of the growth substrate, wherein the number of the second grooves is greater than the number of the first grooves. A first dielectric block is then formed in the first groove and a second dielectric block is formed in the second groove. A buffer layer and an epitaxial functional layer are then formed. The provision of the first and second grooves, and the placement of the first and second dielectric blocks in the first and second grooves, respectively, facilitates the dissociation of the growth substrate in subsequent steps, thereby improving the yield of the micro-LED chip. In the present application, the thickness of the first dielectric block is set to be less than the depth of the first groove, and the thickness of the second dielectric block is set to be less than the depth of the second groove. During the formation of the buffer layer, a portion of the buffer layer is embedded in the first and second grooves. After the growth substrate is dissociated, this portion of the buffer layer forms a raised structure, thereby adjusting the light emission mode of a portion of the micro-LED chip, thereby improving the light emission efficiency of the micro-LED chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram showing a plurality of first grooves and a plurality of second grooves formed in a first region and a second region of a substrate, respectively, in an embodiment of the present invention.

[0026] Figure 2 It is a schematic structural diagram showing a first dielectric block and a second dielectric block formed in a first groove and a second groove, respectively, in an embodiment of the present invention.

[0027] Figure 3 It shows a schematic structural diagram of forming a buffer layer, a transition layer, an epitaxial functional layer, a plurality of first electrodes and a plurality of second electrodes in an embodiment of the present invention.

[0028] Figure 4 It is a schematic diagram showing the structure of forming multiple micro LED chips in an embodiment of the present invention.

[0029] Figure 5 Shown is a schematic structural diagram of a micro-LED display panel for AR / VR full-color display formed in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0031] like Figures 1 to 5 As shown, this embodiment provides a method for preparing a micro LED chip for AR / VR full-color display, the preparation method comprising the following steps:

[0032] like Figure 1 As shown, a substrate 100 is provided, which includes a first area 101 and a second area 102 . The first area 101 is the middle area of the substrate 100 , and the second area 102 is the peripheral area of the substrate. The second area 102 surrounds the first area 101 .

[0033] In a specific embodiment, the area of the first region 101 is the same as the area of the second region 102 , and the substrate 100 is a sapphire substrate.

[0034] like Figure 1 As shown, a plurality of first grooves 1011 are formed in the first region 101 , and a plurality of second grooves 1021 are formed in the second region 102 , where the number of the second grooves 1021 is greater than the number of the first grooves 1011 .

[0035] In a specific embodiment, the first groove 1011 and the second groove 1021 are formed by a wet etching process or a dry etching process, and the depth of the first groove 1011 is greater than the depth of the second groove 1021 .

[0036] In a specific embodiment, the number of the second grooves 1021 is 2-5 times the number of the first grooves 1011, and the depth of the first grooves 1011 is 500 nanometers to 3000 nanometers greater than the depth of the second grooves 1021. By optimizing the difference in the number and depth of the first grooves and the second grooves, the dissociation performance between the growth substrate and the buffer layer is effectively improved, thereby facilitating the dissociation of the substrate, and the dissociated substrate can be reused.

[0037] In a specific embodiment, a photoresist mask (not shown) is formed on the substrate 100. Specifically, a photoresist layer is formed by a spin coating process, and then the photoresist layer is exposed and developed to form a photoresist mask. The substrate 100 is then laser etched using the photoresist mask to form the first groove 1011 and the second groove 1021. Specific parameters of the laser etching process are adjusted so that there is a difference in number and depth between the first groove 1011 and the second groove 1021. Specifically, the number of the second grooves 1021 is 2 times, 3 times, 4 times, or 5 times the number of the first grooves 1011, and the depth of the first groove 1011 is 500 nanometers, 800 nanometers, 1200 nanometers, 1500 nanometers, 2000 nanometers, 2500 nanometers, or 3000 nanometers greater than the depth of the second groove 1021.

[0038] like Figure 2 As shown, dielectric materials are deposited in the plurality of first grooves 1011 and the plurality of second grooves 1021 to form first dielectric blocks 201 in the first grooves 1011 and second dielectric blocks 202 in the second grooves 1021 .

[0039] In a specific embodiment, the material of the first dielectric block 201 and the second dielectric block 202 includes one of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, hafnium oxide, and silicon oxynitride, and the preparation process of the first dielectric block 201 and the second dielectric block 202 is a chemical vapor deposition process, an atomic layer deposition process, or a magnetron sputtering process.

[0040] In a specific embodiment, the thickness of the first dielectric block 201 is less than the depth of the first groove 1011, and the thickness of the second dielectric block 202 is less than the depth of the second groove 1021. Specifically, the thickness of the first dielectric block 201 is 100-500 nanometers less than the depth of the first groove 1011, more specifically 100 nanometers, 200 nanometers, 300 nanometers, 400 nanometers or 500 nanometers, and the thickness of the second dielectric block 202 is 100-500 nanometers less than the depth of the second groove 1021, more specifically 100 nanometers, 200 nanometers, 300 nanometers, 400 nanometers or 500 nanometers.

[0041] In a specific embodiment, the above-mentioned photoresist mask is used to deposit silicon oxide or silicon oxynitride by PECVD process to form the first dielectric block 201 and the second dielectric block 202.

[0042] like Figure 3 As shown, a buffer layer 300 is then formed on the substrate 100 and planarized.

[0043] In a specific embodiment, the buffer layer 300 may be aluminum nitride. During the epitaxial growth of the buffer layer 300 on the substrate 100 , a portion of the buffer layer 300 is embedded in the first groove 1011 and the second groove 1021 .

[0044] In a specific embodiment, due to the presence of the first groove 1011 and the second groove 1021, the surface of the epitaxially grown buffer layer 300 is uneven, and then through a mechanical grinding process, the buffer layer 300 becomes a flat surface, which is conducive to the preparation of a high-quality epitaxial layer.

[0045] In a specific embodiment, a transition layer 400 is formed on the planarized buffer layer 300 . More specifically, a non-doped gallium nitride layer is grown on the aluminum nitride buffer layer 300 by a chemical vapor deposition process to serve as the transition layer 400 .

[0046] like Figure 3 As shown, an epitaxial functional layer 500 is then epitaxially grown on the substrate 100, and the epitaxial functional layer 500 includes a first semiconductor layer, a multi-quantum well layer, and a second semiconductor layer, wherein the first semiconductor layer and the second semiconductor layer are gallium nitride layers with different doping types, specifically, the first semiconductor layer is a silicon-doped n-type gallium nitride layer, and the second semiconductor layer is a magnesium-doped p-type gallium nitride layer; the multi-quantum well layer is an alternately grown InGaN quantum well layer and a GaN quantum barrier layer, the thickness of the first semiconductor layer and the second semiconductor layer is 1-4 microns, and the thickness of the multi-quantum well layer can be 100-200 nanometers.

[0047] like Figure 3 As shown, a plurality of first electrodes 601 and a plurality of second electrodes 602 are then formed on the epitaxial functional layer 500 .

[0048] In a specific embodiment, the first electrode 601 is electrically connected to the first semiconductor layer, and the second electrode 602 is electrically connected to the second semiconductor layer. The material of the first electrode 601 and the second electrode 602 includes one or more of gold, silver, titanium, palladium, nickel, and copper. The first electrode 601 and the second electrode 602 are formed by magnetron sputtering or evaporation process.

[0049] like Figure 4 As shown, a temporary carrier 700 is provided, and the substrate 100 is placed on the temporary carrier 700 with the epitaxial functional layer 500 facing the temporary carrier 700 .

[0050] In a specific embodiment, the temporary carrier 700 is any suitable rigid substrate such as metal, semiconductor, ceramic, etc. In order to facilitate the fixation of the substrate 100, a temporary adhesive layer 701 can be set on the temporary carrier 700. In the process of setting the substrate 100 on the temporary carrier 700, the multiple first electrodes 601 and the second electrodes 602 on the substrate 100 are buried in the temporary adhesive layer 701, thereby facilitating the smooth progress of subsequent process steps.

[0051] like Figure 4 As shown, the substrate 100 is then subjected to a dissociation treatment to remove the substrate 100. Due to the presence of the plurality of first grooves 1011 and the plurality of second grooves 1021, and the formation of the first dielectric block 201 in the first groove 1011 and the formation of the second dielectric block 202 in the second groove 1021, the substrate 100 can be quickly and conveniently dissociated, thereby avoiding damage to the epitaxial functional layer, thereby improving the preparation yield of the micro LED chip.

[0052] like Figure 4 As shown, the epitaxial functional layer 500 is then cut to form a plurality of micro LED chips 800 .

[0053] In a specific embodiment, the plurality of micro LED chips 800 are formed by a laser cutting process.

[0054] like Figure 4 As shown, the present invention also proposes a micro LED chip for AR / VR full-color display, which is manufactured using the above-mentioned preparation method of the micro LED chip for AR / VR full-color display.

[0055] like Figure 5 As shown, the present invention also proposes a method for preparing a micro LED display panel for AR / VR full-color display, the preparation method comprising the following steps: providing a driving substrate 900, providing the above-mentioned micro LED chip 800 for AR / VR full-color display, and transferring the micro LED chip 800 to the driving substrate 900 to form a micro LED display panel for AR / VR full-color display.

[0056] In a specific embodiment, the first electrode 601 and the second electrode 602 of each LED chip transfer 800 are electrically connected to the driving substrate 900 .

[0057] like Figure 5 As shown, the present invention also proposes a micro LED display panel for AR / VR full-color display, which is manufactured using the above-mentioned preparation method of the micro LED display panel for AR / VR full-color display.

[0058] In other preferred technical solutions, the present invention proposes a method for preparing a micro-LED chip for AR / VR full-color display, the preparation method comprising the following steps:

[0059] A substrate is provided. The substrate includes a first region and a second region. The first region is a middle region of the substrate, and the second region is a peripheral region of the substrate. The second region surrounds the first region.

[0060] A plurality of first grooves are formed in the first region, and a plurality of second grooves are formed in the second region, wherein the number of the second grooves is greater than the number of the first grooves.

[0061] A dielectric material is deposited in the plurality of first grooves and the plurality of second grooves to form a first dielectric block in the first grooves and a second dielectric block in the second grooves.

[0062] Then, a buffer layer is formed on the substrate, and the buffer layer is planarized.

[0063] Then, an epitaxial functional layer is epitaxially grown on the substrate.

[0064] Then, a plurality of first electrodes and a plurality of second electrodes are formed on the epitaxial functional layer.

[0065] A temporary carrier is provided, and the substrate is placed on the temporary carrier with the epitaxial functional layer facing the temporary carrier.

[0066] Then, the substrate is subjected to a dissociation process to remove the substrate;

[0067] The epitaxial functional layer is then cut to form a plurality of micro LED chips.

[0068] In a more preferred technical solution, the area of the first region is the same as the area of the second region, and the substrate is a sapphire substrate.

[0069] In a more preferred technical solution, the first groove and the second groove are formed by a wet etching process or a dry etching process, and the depth of the first groove is greater than the depth of the second groove.

[0070] In a more preferred technical solution, the material of the first dielectric block and the second dielectric block includes one of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, hafnium oxide, and silicon oxynitride, and the preparation process of the first dielectric block and the second dielectric block is a chemical vapor deposition process, an atomic layer deposition process, or a magnetron sputtering process.

[0071] In a more preferred technical solution, the thickness of the first dielectric block is smaller than the depth of the first groove, and the thickness of the second dielectric block is smaller than the depth of the second groove.

[0072] In a more preferred technical solution, during the process of forming the buffer layer on the substrate, a portion of the buffer layer is embedded in the first groove and the second groove.

[0073] In a more preferred technical solution, before epitaxially growing the epitaxial functional layer on the substrate, a transition layer is formed on the buffer layer after the planarization treatment.

[0074] In other preferred technical solutions, the present invention also proposes a micro LED chip for AR / VR full-color display, which is manufactured using the above-mentioned preparation method of the micro LED chip for AR / VR full-color display.

[0075] In other preferred technical solutions, the present invention also proposes a method for preparing a micro-LED display panel for AR / VR full-color display, the preparation method comprising the following steps: providing a driving substrate, providing the above-mentioned micro-LED chip for AR / VR full-color display, and transferring the micro-LED chip to the driving substrate to form a micro-LED display panel for AR / VR full-color display.

[0076] In other preferred technical solutions, the present invention also proposes a micro-LED display panel for AR / VR full-color display, which is manufactured using the above-mentioned preparation method of the micro-LED display panel for AR / VR full-color display.

[0077] In the method for preparing a micro-LED chip for AR / VR full-color display of the present application, a plurality of first grooves are formed in a first region of a growth substrate, and a plurality of second grooves are formed in a second region of the growth substrate, wherein the number of the second grooves is greater than the number of the first grooves. A first dielectric block is then formed in the first groove and a second dielectric block is formed in the second groove. A buffer layer and an epitaxial functional layer are then formed. The provision of the first and second grooves, and the placement of the first and second dielectric blocks in the first and second grooves, respectively, facilitates the dissociation of the growth substrate in subsequent steps, thereby improving the yield of the micro-LED chip. In the present application, the thickness of the first dielectric block is set to be less than the depth of the first groove, and the thickness of the second dielectric block is set to be less than the depth of the second groove. During the formation of the buffer layer, a portion of the buffer layer is embedded in the first and second grooves. After the growth substrate is dissociated, this portion of the buffer layer forms a raised structure, thereby adjusting the light emission mode of some micro-LED chips and improving the light emission efficiency of some micro-LED chips.

[0078] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for preparing a micro-LED chip for AR / VR full-color display, characterized by: The preparation method comprises the following steps: Providing a substrate, the substrate comprising a first region and a second region, the first region being a middle region of the substrate, the second region being a peripheral region of the substrate, and the second region surrounding the first region; forming a plurality of first grooves in the first region and a plurality of second grooves in the second region, wherein the number of the second grooves is 2-5 times the number of the first grooves, and the depth of the first grooves is 500 nanometers to 3000 nanometers greater than the depth of the second grooves; Depositing a dielectric material in the plurality of first grooves and the plurality of second grooves to form a first dielectric block in the first grooves and a second dielectric block in the second grooves, wherein a thickness of the first dielectric block is 100-500 nanometers less than a depth of the first grooves, and a thickness of the second dielectric block is 100-500 nanometers less than a depth of the second grooves; Then, forming a buffer layer on the substrate and performing a planarization process on the buffer layer, wherein a portion of the buffer layer is embedded in the first groove and the second groove during the formation of the buffer layer; Then, epitaxially growing an epitaxial functional layer on the substrate; Then forming a plurality of first electrodes and a plurality of second electrodes on the epitaxial functional layer; Providing a temporary carrier, placing the substrate on the temporary carrier with the epitaxial functional layer facing the temporary carrier; Then, the substrate is subjected to a dissociation process to remove the substrate; The epitaxial functional layer is then cut to form a plurality of micro LED chips.

2. The method for preparing a micro-LED chip for AR / VR full-color display according to claim 1, characterized in that: The area of the first region is the same as the area of the second region, and the substrate is a sapphire substrate.

3. The method for preparing a micro-LED chip for AR / VR full-color display according to claim 1, characterized in that: The first groove and the second groove are formed by a wet etching process or a dry etching process.

4. The method for preparing a micro-LED chip for AR / VR full-color display according to claim 1, characterized in that: The material of the first dielectric block and the second dielectric block includes one of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, hafnium oxide, and silicon oxynitride. The preparation process of the first dielectric block and the second dielectric block is chemical vapor deposition process, atomic layer deposition process or magnetron sputtering process.

5. The method for preparing a micro-LED chip for AR / VR full-color display according to claim 1, characterized in that: Before epitaxially growing an epitaxial functional layer on the substrate, a transition layer is formed on the buffer layer after the planarization process.

6. A micro LED chip for AR / VR full-color display, characterized in that: The micro LED chip for AR / VR full-color display is manufactured using the preparation method of any one of claims 1 to 5.

7. A method for preparing a micro-LED display panel for AR / VR full-color display, characterized in that: The preparation method includes the following steps: providing a driving substrate, providing the micro LED chip for AR / VR full-color display according to claim 6, and transferring the micro LED chip to the driving substrate to form a micro LED display panel for AR / VR full-color display.

8. A micro LED display panel for AR / VR full-color display, characterized in that: The micro-LED display panel for AR / VR full-color display is manufactured using the method for preparing the micro-LED display panel for AR / VR full-color display according to claim 7.

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