LED structure and preparation method thereof, and light field display system

Abstract

The present invention discloses an LED structure and a preparation method thereof, and a light field display system. The LED structure comprises: a substrate; a plurality of LED chips arranged on the substrate, each of the LED chips comprising a first doped semiconductor layer, an active layer, and a second doped semiconductor layer sequentially stacked on the substrate; an isolation groove is arranged between the first doped semiconductor layers of any two adjacent LED chips, and the isolation groove is used to isolate the first doped semiconductor layers corresponding to the two adjacent LED chips; a light blocking structure is arranged in each isolation groove, and the light blocking structure is used to block the light path between the first doped semiconductor layers corresponding to the two adjacent LED chips. The present invention can reduce the light crosstalk between LED chips.

Description

Technical Field

[0001] The embodiments of the present invention relate to LED technology, and in particular to an LED structure and a preparation method thereof, and a light field display system. Background Art

[0002] With the development of display lighting and other technologies, LED chips, such as Micro-LED or Mini-LED, are becoming more and more widely used due to their higher brightness and lower power consumption, and correspondingly, the requirements for LED chips are also getting higher and higher.

[0003] However, existing LED chips have the problem of optical crosstalk, which seriously limits the further application of LED chips. Summary of the invention

[0004] The present invention provides an LED structure and a preparation method thereof, and a light field display system, so as to improve the light crosstalk problem of LED chips.

[0005] In the first aspect, an embodiment of the present invention provides an LED structure, which includes: a substrate; a plurality of LED chips arranged on the substrate, each of the LED chips including a first doped semiconductor layer, an active layer and a second doped semiconductor layer stacked in sequence on the substrate; an isolation groove is provided between the first doped semiconductor layers of any two adjacent LED chips, and the isolation groove is used to isolate the first doped semiconductor layers corresponding to the two adjacent LED chips; a light blocking structure is provided in each isolation groove, and the light blocking structure is used to block the light path between the first doped semiconductor layers corresponding to the two adjacent LED chips.

[0006] Optionally, the LED chip also includes a first electrode arranged on the side of the second doped semiconductor layer away from the active layer; the light blocking structure is a conductive structure, and the light blocking structure is in contact with the adjacent first doped semiconductor layer; the light blocking structure is reused as the second electrode of the LED chip.

[0007] Optionally, the first doped semiconductor layer is in a stepped shape including a first sublayer and a second sublayer; the size of the second sublayer is smaller than that of the first sublayer, the second sublayer is arranged on a side of the first sublayer away from the substrate, and the second sublayer exposes an edge area of ​​a side of the first sublayer away from the substrate; the light blocking structure fills the isolation groove and covers at least a portion of the first sublayer located in the edge area;

[0008] Alternatively, the size of the active layer is smaller than the size of the first doped semiconductor layer on a side close to the active layer, and the active layer exposes the edge area of ​​the first doped semiconductor layer; the light blocking structure fills the isolation groove and covers at least part of the first doped semiconductor layer located in the edge area.

[0009] Optionally, the LED chip is also provided with a super surface structure.

[0010] Optionally, the metasurface structure corresponding to the LED chip is configured to adjust the light emitting direction of the LED chip to be offset toward the central area of ​​the LED structure.

[0011] Optionally, a groove is formed on a side of the first doped semiconductor layer of the LED chip close to the substrate, and a portion of the first doped semiconductor layer close to the substrate forms the super-surface structure.

[0012] Optionally, the first doped semiconductor layer and the substrate are fixed via colloid, and the colloid fills the groove.

[0013] Optionally, a super-surface structure layer is formed on a side of the first doped semiconductor layer of the LED chip close to the substrate.

[0014] Optionally, a first ion implantation structure is formed on a portion of the first doped semiconductor layer of the LED chip close to the substrate, and the first ion implantation structure forms the super-surface structure.

[0015] Optionally, a second ion implantation structure is provided at an edge of the second doped semiconductor layer.

[0016] Optionally, the LED chip also includes a first electrode arranged on the side of the second doped semiconductor layer away from the active layer; the first electrode is configured as follows: the center point of a side close to the second doped semiconductor layer is at the positive projection point of the first doped semiconductor layer close to the substrate side, and the angle between the two line segments formed by the two points of the first electrode farthest from the side close to the second doped semiconductor layer is less than or equal to a preset value.

[0017] Optionally, an anti-total reflection film is provided on a side of the substrate away from the LED chip.

[0018] In the second aspect, an embodiment of the present invention further provides a method for preparing an LED structure, the preparation method comprising: forming a substrate; forming a plurality of LED chips and a light-blocking structure, wherein each of the LED chips comprises a first doped semiconductor layer, an active layer and a second doped semiconductor layer sequentially stacked on the substrate; an isolation groove is provided between the first doped semiconductor layers of any two adjacent LED chips, the isolation groove being used to isolate the first doped semiconductor layers corresponding to the two adjacent LED chips; a light-blocking structure is provided in each isolation groove, the light-blocking structure being used to block the light path between the first doped semiconductor layers corresponding to the two adjacent LED chips.

[0019] Optionally, forming a plurality of LED chips and a light blocking structure includes:

[0020] Epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material stacked in sequence; etching the second doped semiconductor layer material and the active layer material to form an isolation hole, wherein the isolation hole exposes the first doped semiconductor layer material; continuing to etch the first doped semiconductor layer material in the isolation hole to form the isolation groove; along the thickness direction of the LED structure, the orthographic projection of the isolation groove overlaps with the orthographic projection of the isolation hole; forming the light blocking structure in the isolation groove;

[0021] Alternatively, epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material stacked in sequence; etching the second doped semiconductor layer material and the active layer material to form an isolation hole, wherein the isolation hole exposes the first doped semiconductor layer material; etching the first doped semiconductor layer material in the isolation hole to form the isolation groove, so that the isolation hole exposes the isolation groove and the edge area of ​​the first doped semiconductor layer of the LED chip; forming the light blocking structure in the isolation hole and the isolation groove, wherein the light blocking structure fills the isolation groove and covers at least part of the first doped semiconductor layer located in the edge area; the light blocking structure is a conductive structure;

[0022] Alternatively, epitaxially form a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material which are stacked in sequence; etch the second doped semiconductor layer material, the active layer material and part of the first doped semiconductor layer material to form an isolation hole, wherein the isolation hole exposes the first doped semiconductor layer material that has not been etched; etch the first doped semiconductor layer material in the isolation hole to form the isolation groove to form a stepped first doped semiconductor layer, wherein the isolation hole exposes the isolation groove and the edge area of ​​the first doped semiconductor layer of the LED chip; form the light-blocking structure in the isolation hole and the isolation groove, wherein the light-blocking structure fills the isolation groove and covers at least part of the first doped semiconductor layer located in the edge area; the light-blocking structure is a conductive structure.

[0023] Optionally, the preparation method further comprises: after forming the plurality of LED chips and the light blocking structure, the method further comprises:

[0024] A metasurface structure corresponding to each LED chip is formed.

[0025] Optionally, the preparation method comprises:

[0026] Forming a first temporary substrate; epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material stacked in sequence on the first temporary substrate; bonding a second temporary substrate to one side of the second doped semiconductor layer material; removing the first temporary substrate to expose the first doped semiconductor layer material; etching the first doped semiconductor layer material to form the supersurface structure; fixing the substrate to one side of the supersurface structure; and removing the second temporary substrate;

[0027] Alternatively, the preparation method comprises: forming a first temporary substrate; epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material stacked in sequence on the first temporary substrate; bonding a second temporary substrate to one side of the second doped semiconductor layer material; removing the first temporary substrate to expose the first doped semiconductor layer material; forming a super surface structure layer on a side of the first doped semiconductor layer material away from the active layer material; etching the super surface structure layer to form the super surface structure; fixing the substrate to one side of the super surface structure; and removing the second temporary substrate;

[0028] Alternatively, the preparation method comprises: forming a first temporary substrate; epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material stacked in sequence on the first temporary substrate; bonding a second temporary substrate to one side of the second doped semiconductor layer material; removing the first temporary substrate to expose the first doped semiconductor layer material; ion implanting the first doped semiconductor layer material to form the super surface structure; fixing the substrate to one side of the super surface structure; and removing the second temporary substrate;

[0029] Alternatively, the forming of the supersurface structure includes: forming the substrate; forming a supersurface structure layer on the substrate; etching the supersurface structure layer material to form the supersurface structure; and flattening the supersurface structure.

[0030] In a third aspect, an embodiment of the present invention further provides a light field display system, wherein the light field display system comprises the LED structure and the optical imaging lens described in the first aspect.

[0031] The technical solution of the embodiment of the present invention adopts an LED structure including: a substrate; a plurality of LED chips arranged on the substrate, each LED chip including a first doped semiconductor layer, an active layer and a second doped semiconductor layer stacked in sequence on the substrate; an isolation groove is arranged between the first doped semiconductor layers of any two adjacent LED chips, the isolation groove is used to isolate the first doped semiconductor layers corresponding to the two adjacent LED chips; a light blocking structure is arranged in each isolation groove, the light blocking structure is used to block the light path between the first doped semiconductor layers corresponding to the two adjacent LED chips. The isolation groove separates a whole layer of first doped semiconductor layers originally continuous on the substrate into first doped semiconductor layers corresponding to each LED chip; and by arranging the light blocking structure in the isolation groove, the continuity between the first doped semiconductors of different LED chips is cut off, that is, the optical waveguide is cut off, thereby avoiding the light emitted by different LED chips from propagating to other LED chips through the first doped semiconductor layer to cause light crosstalk. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of an LED structure provided by an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of a LED structure provided in an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of another LED structure provided by an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of another LED structure provided by an embodiment of the present invention;

[0036] Figure 5 A schematic diagram of another LED structure provided by an embodiment of the present invention;

[0037] Figure 6 A schematic diagram of another LED structure provided by an embodiment of the present invention;

[0038] Figure 7 A schematic diagram of another LED structure provided by an embodiment of the present invention;

[0039] Figure 8 An enlarged view of an LED chip provided by an embodiment of the present invention;

[0040] Fig. 9 A schematic diagram of another LED structure provided by an embodiment of the present invention;

[0041] Fig.10 A flow chart of a method for preparing an LED structure provided by an embodiment of the present invention;

[0042] Figures 11 to 29 A schematic diagram of a structure formed corresponding to the main steps of the method for preparing an LED structure provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0044] As mentioned in the background technology, the existing LED structure will have the problem of optical crosstalk. After careful research, the inventors found that the reason for this problem is that for the Micro-LED with a flip-chip structure, it is necessary to use flip-chip welding to electrically connect with the driver IC, so the anode and cathode need to be made on the same side. Taking the common cathode chip as an example, when the Micro-LED is patterned, the etching depth will be controlled so that the light-emitting layer is completely cut off, but most of the thickness of the N-type doped layer will be retained, and a layer of metal electrode will be made on the surface of the N-type doped layer to form a common cathode metal network layer. However, under this structure, the continuous N-type doped layer will form an optical waveguide, which will cause optical crosstalk between different LED chips.

[0045] Based on the above technical problems, the present invention proposes the following solutions:

[0046] Figure 1 A schematic diagram of an LED structure provided by an embodiment of the present invention, referring to Figure 1 The LED structure includes: a substrate 10; a plurality of LED chips 11 arranged on the substrate 10, each LED chip 11 includes a first doped semiconductor layer 111, an active layer 112 and a second doped semiconductor layer 113 stacked in sequence on the substrate 10; an isolation groove 12 is arranged between the first doped semiconductor layers 111 of any two adjacent LED chips, and the isolation groove 12 is used to isolate the first doped semiconductor layers 111 corresponding to the two adjacent LED chips 11; a light blocking structure 121 is arranged in each isolation groove 12, and the light blocking structure 121 is used to block the light path between the first doped semiconductor layers corresponding to the two adjacent LED chips.

[0047] Specifically, the LED structure of the present embodiment is a flip-chip structure, that is, the LED structure and the driver chip need to be welded together by flip-chip welding later; the substrate 10 can be, for example, a diamond substrate or a sapphire substrate, and one side of the substrate 10 can be a light-emitting surface, so the substrate 10 can use a transparent substrate; each LED chip 11 typically includes a first doped semiconductor layer 111, an active layer 112, and a second doped semiconductor layer 113, the first doped semiconductor layer 111 can be, for example, an N-type doped semiconductor layer, and further, for example, can be N-type GaN; the second doped semiconductor layer 113 can be, for example, a P-type doped semiconductor layer, and further, for example, can be P-type GaN; the light-emitting principle of the LED chip is well known to those skilled in the art and will not be repeated here; it should be noted that, according to the material of the active layer 112, The LED chip 11 can excite light of different colors due to different materials, and the LED chip may also include other functional layers, such as a reflective layer, etc.; in the present embodiment, an isolation groove 12 is arranged between any two adjacent LED chips 11, and the isolation groove 12 separates the first doped semiconductor layer 111 of each LED chip 11 into an independent structure. In other words, the isolation groove 12 separates a whole layer of first doped semiconductor layer originally continuous on the substrate 10 into first doped semiconductor layers corresponding to each LED chip 11; and by arranging a light blocking structure 121 in the isolation groove 12, the continuity between the first doped semiconductors of different LED chips is cut off, that is, the optical waveguide is cut off, thereby preventing the light emitted by different LED chips 11 from propagating to other LED chips through the first doped semiconductor layer 111 to cause optical crosstalk.

[0048] The technical solution of this embodiment adopts an LED structure including: a substrate; a plurality of LED chips arranged on the substrate, each LED chip including a first doped semiconductor layer, an active layer, and a second doped semiconductor layer stacked in sequence on the substrate; an isolation groove is arranged between the first doped semiconductor layers of any two adjacent LED chips, the isolation groove is used to isolate the first doped semiconductor layers corresponding to the two adjacent LED chips; a light blocking structure is arranged in each isolation groove, the light blocking structure is used to block the light path between the first doped semiconductor layers corresponding to the two adjacent LED chips. The isolation groove separates a whole layer of first doped semiconductor layers originally continuous on the substrate into first doped semiconductor layers corresponding to each LED chip; and by arranging the light blocking structure in the isolation groove, the continuity between the first doped semiconductors of different LED chips is cut off, that is, the optical waveguide is cut off, thereby avoiding the light emitted by different LED chips from propagating to other LED chips through the first doped semiconductor layer to cause light crosstalk.

[0049] It should be noted that a buffer layer may be included between the LED chip and the substrate, and the isolation groove may penetrate the buffer layer.

[0050] In addition, it should be noted that the proportions of the various structural layers in the drawings provided by the present invention are only for illustration and do not represent the proportions of the various structural layers in the actual structure.

[0051] Optionally, continue to refer to Figure 1 The LED chip also includes a first electrode 114 arranged on the side of the second doped semiconductor layer 113 away from the active layer 112; the light blocking structure 121 is a conductive structure, and the light blocking structure 121 is in contact with the adjacent first doped semiconductor layer 111; the light blocking structure 121 is reused as the second electrode of the LED chip 11.

[0052] Specifically, each LED chip 11 requires two electrodes to drive, and the material of the electrodes can be, for example, a single-layer metal or a multi-layer metal alloy; the first electrode 114 is in ohmic contact with the second doped semiconductor layer 113; in this embodiment, metal can be used as the second electrode. Due to the light-shielding property of the metal, it can be used as both a light-blocking structure and a second electrode of the LED chip, so that the second electrode and the light-blocking structure can be produced through only one process, simplifying the production process. It should be noted that in the LED structure, the light-blocking structure can be in a grid shape, and each LED chip 11 is confined within the grid formed by the grid-like structure. At this time, the second electrodes of all LED chips are in a connected state, that is, all LED chips share the second electrode.

[0053] Of course, in some other implementations, the light blocking structure 121 may also only use light blocking materials, and the second electrode may be manufactured by other methods.

[0054] For example, Figure 1 As shown in the figure, the first doped semiconductor layer 111 is step-shaped, and may specifically include a first sublayer and a second sublayer; the size of the second sublayer is smaller than that of the first sublayer, and the second sublayer is arranged on the side of the first sublayer away from the substrate, and the second sublayer exposes the edge area of ​​the side of the first sublayer away from the substrate; the light-blocking structure fills the isolation groove and covers at least a portion of the first sublayer located in the edge area.

[0055] Specifically, in this embodiment, the first doped semiconductor layer 111 is set to be stepped, and the size of the second sublayer is smaller than that of the first sublayer. It can be understood that along the thickness direction of the LED chip, the orthographic projection area of ​​the second sublayer is smaller than the orthographic projection area of ​​the first sublayer, so that the second sublayer can expose the edge area of ​​the first sublayer; the conductive structure not only fills the isolation groove, but also covers at least part of the first sublayer located in the edge area. Due to the limitation of the conductive structure manufacturing process, the conductive structure and the side of the first sublayer away from the substrate can form a relatively good ohmic contact, thereby reducing the contact resistance and power consumption. In addition, since the first doped semiconductor layer 111 is usually thick, in this embodiment, by setting the first doped semiconductor layer to be stepped, the thickness of the isolation groove can be made smaller, reducing the difficulty of filling the conductive structure.

[0056] It should be noted that in some other implementations, the isolation trench may be filled with a conductive structure or a non-conductive structure, as long as a conductive structure is subsequently fabricated to form an ohmic contact with the first sub-layer.

[0057] For example, Figure 2 A schematic diagram of a LED structure is provided in an embodiment of the present invention, referring to Figure 2 The size of the active layer 112 is smaller than the size of the first doped semiconductor layer 111 close to the active layer 112, and the active layer 112 exposes the edge area of ​​the first doped semiconductor layer; the light blocking structure 121 fills the isolation groove 12 and covers at least part of the first doped semiconductor layer 111 located in the edge area.

[0058] Specifically, different from the above embodiment, the first doped semiconductor layer in this embodiment is not in a step shape, and the first doped semiconductor layer and the active layer are in a step shape as a whole, and the thickness of the isolation groove 12 is the same as the thickness of the first doped semiconductor layer 111. Similar to the above embodiment, a non-conductive structure can also be filled in the isolation groove, as long as the conductive structure is subsequently used to form an ohmic contact with the side of the first doped semiconductor layer away from the substrate.

[0059] For example, Figure 3 As shown, Figure 3 A schematic diagram of another LED structure provided in an embodiment of the present invention is different from the above embodiment in that, in this embodiment, along the thickness direction of the LED chip, the orthographic projection areas of the first doped semiconductor layer, the active layer, and the second doped semiconductor layer are the same. At this time, a conductive structure can be formed in the isolation groove to contact the sidewall of the first doped semiconductor layer to achieve electrical connection; the thickness of the conductive structure can be less than or equal to the thickness of the first doped semiconductor layer. In the solution of this embodiment, the second doped semiconductor layer, the active layer, and the first doped semiconductor layer can be etched with only one etching, and the number of mask plates required is small, and the number of etching times is small, which is conducive to reducing the difficulty of the process.

[0060] Optionally, Figure 4 A schematic diagram of another LED structure provided by an embodiment of the present invention, referring to Figure 4 , the LED chip is also provided with a super surface structure 13.

[0061] Specifically, in certain application scenarios, such as projection technology, the LED structure not only needs to avoid the problem of light crosstalk, but also requires a higher luminous brightness. In this embodiment, by setting a super surface structure 13, the super surface structure 13 is a nano super surface layer, and the nano super surface structure can be set at the interface where the refractive index changes (for example, the light emitting surface of the first doped semiconductor layer). By setting a graphical nano super surface structure, the phase of the light beam at the interface can be changed, thereby changing the propagation direction of the light beam, which can not only make the light beam originally confined in the optical waveguide emerge, but also make most of the light emitted by the LED chip emerge as a narrow beam, so that it can be collected by the imaging device in the projection system, thereby greatly improving the overall brightness of the system. In addition, since almost all light beams can be emitted from the substrate waveguide, the super surface structure will also greatly reduce the far-field crosstalk caused by light transmission in the substrate waveguide. The super surface structure is a structure composed of a sub-wavelength structure array. By designing a suitable sub-wavelength structure, the phase, amplitude, polarization state, etc. of the incident light can be controlled.

[0062] For example, when the size of the light-emitting surface (the side of the first doped semiconductor layer away from the active layer) is 16 μm and the thickness of the first doped semiconductor layer is 4 μm, when most of the light beams emitted by the LED chip are incident on the metasurface structure, the propagation direction of the light beams is changed and emitted to the outside of the LED structure as narrow light beams. This part of the light beam can enter the imaging device. At this time, the light-emitting angle of the LED structure light source that is effectively utilized is related to the LED structure. According to the geometric relationship, by It can be calculated that the half angle of the effective luminous angle is about 70 degrees; according to the calculation formula of effective light collection efficiency, The effective light collection efficiency is calculated to be 66%, which is about 100 times higher than that of an LED structure without a nano-metasurface structure (the light extraction efficiency is calculated in a similar way to the above formula, and its effective light emission angle is calculated to be 6.4°, and the light extraction efficiency is approximately 0.62%).

[0063] In addition, it should be noted that the super surface structure 13 corresponding to each LED chip is a graphical surface with nanometer-sized microstructures arranged in a certain pattern. The nano-graphics can be, for example, cylinders, truncated cones, cones, circular holes, etc. The diameter and depth of the nano-graphics can be arbitrarily designed. These graphics are arranged according to a uniform period (sub-wavelength range) or randomly distributed in two dimensions. Changes in the diameter, depth (height) and arrangement of the nano-graphics will bring about different phase changes, causing the propagation direction of the light beam at the interface to change, and the purpose of arbitrarily controlling the direction of the light beam can be achieved.

[0064] Preferably, the metasurface structure corresponding to the LED chip is configured to adjust the light emitting direction of the LED chip to be offset toward the central area of ​​the LED structure. In other words, by adjusting the parameters of the metasurface structure corresponding to each LED chip, the light emitting direction of all LED chips is moved closer to the central area of ​​the LED structure, which can improve the light emitting efficiency while controlling the main propagation direction of the narrow light beam, so that most of the light energy emitted by the edge LED chip can be received by the imaging device. That is, the overall light emitting angle of the LED structure is narrower, which is more conducive to the application of projection and other technologies.

[0065] In addition, in addition to improving light efficiency and controlling the direction of light beam propagation, the metasurface structure can also regulate the light output performance of each LED chip. Combining this technology with projection display can achieve light field display effects. By designing the microstructure of the metasurface structure, including parameters such as shape, period, and depth, the imaging depth, imaging size, and virtuality of each LED chip can be controlled. At the same time, the polarization state of the light emitted by the LED chip can also be controlled. By designing the structure of the metasurface structure according to display requirements, multiple imaging planes with two polarization states can be realized at the same time, providing a good foundation for light field display. In this case, the formation of multiple imaging planes by the LED chip will reduce the display resolution. At this time, combined with galvanometer scanning, the method of exchanging time for space can solve the problem of insufficient resolution, and ultimately there is a chance to achieve high-resolution light field display effects with multiple layers of focusing planes.

[0066] For example, Figure 4 As shown, a groove is formed on one side of the first doped semiconductor layer of the LED chip close to the substrate, and a portion of the first doped semiconductor layer close to the substrate 10 forms a super surface structure.

[0067] Specifically, in this embodiment, the supersurface structure 13 can be directly manufactured on the first doped semiconductor layer 111, specifically by etching the first doped semiconductor layer 111 (which will be described in detail later), without increasing the overall thickness of the LED structure, which is conducive to the thinning of the LED structure.

[0068] For example, continue to refer to Figure 4In the groove formed by the first doped semiconductor layer, a colloidal structure can be filled to make the connection between the first doped semiconductor layer and the substrate more secure. Of course, other structures can also be filled in the groove. It should be noted that the parameters of the metasurface structure can be designed according to the refractive index characteristics of the material filled in the groove, for example, the depth of the groove can be set according to the refractive index characteristics.

[0069] Optionally, Figure 5 A schematic diagram of another LED structure provided by an embodiment of the present invention, referring to Figure 5 A super surface structure 13 is formed on a side of the first doped semiconductor layer 111 of the LED chip close to the substrate.

[0070] Specifically, different from the above-mentioned embodiment, in this embodiment, the super surface structure 13 is formed outside the first doped semiconductor layer 111, and the super surface structure is not formed by using the first doped semiconductor layer 111. The specific formation method will be described later. Since it is not necessary to destroy the first doped semiconductor layer, the risk of damage to the LED chip caused by destroying the first doped semiconductor layer can be reduced. In this embodiment, the material of the super surface structure 13 can be metal, for example.

[0071] Optionally, Figure 6 A schematic diagram of another LED structure provided by an embodiment of the present invention, referring to Figure 6 An ion implantation structure 131 is formed on a portion of the first doped semiconductor layer 111 of the LED chip close to the substrate, and the first ion implantation structure 131 forms a super surface structure 13 .

[0072] Specifically, in this embodiment, ion columns can be formed by ion implantation into the first doped semiconductor layer 111 and implantation to a certain depth, so that the ion implantation area forms a nano-patterned distribution. The function of the ion implantation area is to locally break the consistency of the crystal. The patterned ion implantation area can also modulate the phase of the light beam at the interface. Reasonable design of the width, period and implantation depth of the ion beam implantation area, as well as the implanted ions and ion concentration, can well control the propagation direction of the light beam at the interface. By adopting the ion implantation method, the surface flatness of the first doped semiconductor layer 111 is not destroyed. During the process of substrate bonding (which will be explained later), there is no effect on the nano-pattern area, and the control effect of the nano-pattern on the light beam is not affected.

[0073] Optionally, Figure 7 A schematic diagram of another LED structure provided by an embodiment of the present invention, referring to Figure 7 A second ion implantation structure 11311 is disposed at an edge of the second doped semiconductor layer 113 .

[0074] Specifically, the LED structure of this embodiment can be applied to the field of projection display. The narrower the light-emitting angle of each LED chip, the better. Therefore, ion implantation can be performed on the edge of the second doped semiconductor layer 113. Specifically, the ion implantation can be performed vertically before each LED chip is pixelated, or the ion implantation can be performed from the side of the second doped semiconductor layer after the LED chip is pixelated. The ion implantation area is in a high-resistance state, and the area will not undergo carrier conformation, so it does not emit light. The effective light-emitting area can be reduced without physically destroying the crystal structure, thereby reducing the light output angle. It should be noted that when ion implantation is performed by vertical implantation, the depth of ion implantation can be controlled so that the ions are as close to the active layer as possible, but not implanted into the active layer.

[0075] For example, taking a blue LED chip as an example, the Micro-LED structure proposed in the present invention has a light-emitting interface length of 16um*16um, a first doped semiconductor layer thickness of about 4um, and a second doped semiconductor layer thickness of about 300nm. Since the second doped semiconductor layer has a high resistivity, ion implantation can be performed from one side of the second doped semiconductor layer to a position of the second doped semiconductor layer close to the active layer. The length and width of the ion implantation region are 12um, respectively, which is less than the light-emitting interface length. At this time, the effective light-emitting area is 4um*4um.

[0076] Optionally, Figure 8 This is an enlarged view of an LED chip provided by an embodiment of the present invention, referring to Figure 8 The LED chip also includes a first electrode 114 arranged on the side of the second doped semiconductor layer 113 away from the active layer 112; the first electrode 114 is configured as follows: the center point of a side close to the second doped semiconductor layer 113 is at the positive projection point of a side of the first doped semiconductor layer close to the substrate, and the angle between the two line segments formed by the two points of the first electrode 114 farthest from a side close to the second doped semiconductor layer 113 is less than or equal to a preset value.

[0077] Specifically, since the size of the first electrode 114 also affects the light output angle of the LED chip, in the part of the second doped semiconductor layer that does not contact the first electrode, due to the high resistivity, the active layer corresponding to this area will not have a large amount of carrier recombination, so this area will not form effective light output, or very little light output. The center point of the side of the first electrode close to the second doped semiconductor layer 113 is the geometric center point of the surface. If the first electrode is cylindrical, the center point is a dot; the center point is the orthographic projection point of the side of the first doped semiconductor layer close to the substrate, which is approximately the center point of the LED chip's emitted light. The center point of the emitted light and the two points on the side of the first electrode close to the second doped semiconductor layer that are farthest apart form two line segments. The smaller the angle between the two line segments, the narrower the light output angle of the LED chip; the preset value can be less than or equal to the light receiving angle of the imaging device in the projection system, for example, the preset value is 16 degrees. Of course, in some other embodiments, the preset value can also be other values. This embodiment can further reduce the light emission angle of the LED chip by limiting the size of the first electrode.

[0078] Optionally, Fig. 9 A schematic diagram of another LED structure provided by an embodiment of the present invention, referring to Fig. 9 The LED structure also includes an anti-total reflection film 14 disposed on the side of the substrate away from the LED chip. The anti-total reflection film is used to prevent total reflection when light is emitted from the substrate to the outside of the LED structure. The anti-total reflection film 14 can be, for example, an anti-reflection film or a gradient refractive index film, so that as much light beam in the substrate as possible is emitted, while improving the light extraction efficiency, it can also reduce the far-field crosstalk caused by light transmission in the substrate.

[0079] The embodiment of the present invention also provides a method for preparing an LED structure. Fig.10 A flowchart of a method for preparing an LED structure provided by an embodiment of the present invention, referring to Fig.10 , the above-mentioned preparation method comprises:

[0080] Step S210, forming a substrate; Step S220, forming a plurality of LED chips and a light-blocking structure, wherein each LED chip includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer sequentially stacked on the substrate; an isolation groove is provided between the first doped semiconductor layers of any two adjacent LED chips, and the isolation groove is used to isolate the first doped semiconductor layers corresponding to the two adjacent LED chips; a light-blocking structure is provided in each isolation groove, and the light-blocking structure is used to block the light path between the first doped semiconductor layers corresponding to the two adjacent LED chips.

[0081] In the LED structure prepared in this embodiment, the isolation groove separates the entire first doped semiconductor layer originally continuous on the substrate into the first doped semiconductor layer corresponding to each LED chip; and by arranging a light blocking structure in the isolation groove, the continuity between the first doped semiconductors of different LED chips is cut off, that is, the optical waveguide is cut off, thereby preventing the light emitted by different LED chips from propagating to other LED chips through the first doped semiconductor layer and causing optical crosstalk.

[0082] Optionally, Figures 11 to 29 A schematic diagram of a structure formed corresponding to the main steps of the method for preparing an LED structure provided by an embodiment of the present invention;

[0083] Forming a plurality of LED chips and a light blocking structure includes:

[0084] like Fig.11 As shown, epitaxy is performed to form a first doped semiconductor layer material 1110, an active layer material 1120, and a second doped semiconductor layer material 1130 stacked in sequence. The epitaxy method may be, for example, MOCVD. It should be noted that the growth substrate during epitaxy is not necessarily Fig.11 The substrate 10 shown in FIG. Fig.11 Only the substrate 10 is used for illustration.

[0085] like Fig.12 As shown, the second doped semiconductor layer material and the active layer material are etched to form an isolation hole, and the isolation hole exposes the first doped semiconductor layer material; the first doped semiconductor layer material is continuously etched in the isolation hole to form an isolation groove; along the thickness direction of the LED structure, the orthographic projection of the isolation groove overlaps with the orthographic projection of the isolation hole; in this embodiment, the second doped semiconductor layer and the active layer are taken as an integral structure, and the isolation hole can be understood as the part between two adjacent integral structures; the isolation groove is the part between two adjacent first doped semiconductor layers; in this embodiment, a mask plate is used, and the second doped semiconductor layer 113, the active layer 112 and the first doped semiconductor layer 111 can be completely etched out by one etching, and the required mask plates and etching steps are less, which is conducive to simplifying the process steps and reducing the process cost.

[0086] Subsequently, a light blocking structure is formed in the isolation groove. The light blocking structure can be a conductive structure, so as to be reused as an electrode of the LED chip, and finally form a Figure 3 The structure shown.

[0087] Or, if Fig.13 As shown, after the first doped semiconductor layer material, the active layer material and the second doped semiconductor layer material are sequentially stacked by epitaxial formation, an etching may be performed first, that is, etching the second doped semiconductor layer material and the active layer material to form an isolation hole 1131, wherein the isolation hole 1131 exposes the first doped semiconductor layer material 1110; then as shown in FIG. Fig.14 As shown, the first doped semiconductor layer material is etched in the isolation hole to form an isolation groove 12, so that the isolation hole exposes the isolation groove and the edge area of ​​the first doped semiconductor layer of the LED chip; in this scheme, through secondary etching, the first doped semiconductor layer, the active layer and the second doped semiconductor layer can form an integral step structure; then, a light-blocking structure is formed in the isolation hole and the isolation groove. Specifically, two manufacturing processes are performed to first fill the isolation groove with a light-blocking structure, which can be a conductive structure, and then a second manufacturing process is performed to form a conductive structure in the isolation hole that forms an ohmic contact with the portion of the first doped semiconductor layer located in the edge area, thereby reducing the contact resistance and reducing the power consumption of the LED chip. This embodiment finally forms Figure 2 The structure shown.

[0088] Or, if Fig.15 As shown, after epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material stacked in sequence, the second doped semiconductor layer material, the active layer material, and a portion of the first doped semiconductor layer material are etched to form an isolation hole 1131, and the isolation hole 1131 exposes the first doped semiconductor layer material that has not been etched; in this embodiment, the second doped semiconductor layer material and the active layer material are first etched through using a single etching process, but only a portion of the first doped semiconductor layer material is etched, thereby forming a groove on the first doped semiconductor layer material;

[0089] Then, if Fig.16 As shown, the first doped semiconductor layer material is etched in the isolation hole to form a stepped first doped semiconductor layer 111, and the isolation hole exposes the isolation groove and the edge area of ​​the first doped semiconductor layer of the LED chip; in this embodiment, the size of the isolation groove is smaller than the size of the isolation hole, so that the first doped semiconductor layer 111 is stepped, and through two etchings, the depth of the isolation groove can be made smaller, which is convenient for compatibility with existing metal manufacturing processes.

[0090] Then, if Figure 1 As shown, through two manufacturing processes, such as first filling the isolation groove with a conductive structure, and then forming a conductive structure in ohmic contact with the first doped semiconductor layer in the isolation hole, thereby forming Figure 1 The structure shown in .

[0091] Optionally, before forming the plurality of LED chips and the light blocking structure, the method further includes:

[0092] A metasurface structure corresponding to each LED chip is formed.

[0093] Specifically, for the specific description of the metasurface structure, reference can be made to the description of the LED structure in the embodiment of the present invention, which will not be repeated here.

[0094] Optionally, in this embodiment, before forming the metasurface structure corresponding to each LED chip, the following steps are specifically included:

[0095] like Fig.17 As shown, a first temporary substrate 30 is formed; a first doped semiconductor layer material 1110, an active layer material 1120, and a second doped semiconductor layer material 1130 are sequentially stacked on the first temporary substrate 30 by epitaxy; the first temporary substrate 30 is only used for support and needs to be removed later, so a transparent or opaque substrate can be used; then as shown Fig.18 As shown, the second temporary substrate 31 is bonded to one side of the second doped semiconductor layer material 1130; the second temporary substrate 31 has the same function as the first temporary substrate 30, which is also used for support, so a transparent or opaque substrate can be used; then, as shown Fig.19 As shown, the first temporary substrate is removed by a stripping method, thereby exposing the side of the first doped semiconductor layer material 1110 away from the active layer material 1120; then, as shown Fig. 20 As shown, a plurality of grooves are formed by etching the portion of the first doped semiconductor layer material corresponding to each LED chip, and the portion of the first doped semiconductor layer material not etched relative to the groove forms a super surface structure; then, as shown Fig.21 As shown, the substrate 10 is attached to the side of the first doped semiconductor layer material away from the active layer material by using materials such as colloids; and the second temporary substrate is peeled off; finally, the preparation of the super surface structure is completed, and then the steps of forming the LED chip and the light blocking structure can be performed; it should be noted that when the substrate is fixed on the first doped semiconductor layer material by using the colloid material, it is preferably set to fill the grooves on the first doped semiconductor layer material. The super surface structure made by this solution will not increase the overall thickness of the LED structure.

[0096] Or, if Fig. 22 As shown, in the formation Fig.19 After the structure shown in FIG. 1 , the exposed first doped semiconductor layer material is not etched, but a super surface structure layer 32 is first formed on the side of the first doped semiconductor layer material away from the active layer material; the material of the super surface structure layer 32 can be metal; then, as shown in FIG. Fig.23 As shown, the super surface structure layer is etched to form a super surface structure 13; then, as shown Fig.24As shown, the substrate 10 is fixed to one side of the super surface structure, and the second temporary substrate is removed. In this embodiment, since it is not necessary to etch the first doped semiconductor layer material, it is not necessary to destroy the first doped semiconductor layer, thereby reducing the risk of damage to the LED chip caused by destroying the first doped semiconductor layer. It should be noted that the super surface structure of the metal material can also be fixed to the substrate through a colloidal structure. For the infrared LED structure, a silicon material can be used to form a super surface structure, and the process steps are the same as the above method. The difference is that the substrate 10 can be a silicon dioxide substrate. When the super surface structure 13 is bonded to the substrate 10, the silicon dioxide substrate and the super surface structure can be directly pressurized for eutectic bonding. Preferably, when the eutectic bonding method is adopted, when etching to form the super surface structure, it is necessary to leave some unclosed air flow grooves, which can ensure that after eutectic bonding, the air will not be enclosed between the two substrates to avoid separation between the substrates caused by air expansion when heated.

[0097] Or, if Fig.25 As shown, in the formation Fig.19 After the structure shown, the first doped semiconductor layer material can be directly ion-implanted to form a super surface structure. By using ion implantation to a certain depth, an ion column is formed, so that the ion implantation area forms a nano-patterned distribution. The role of the ion implantation area is to locally break the consistency of the crystal. The patterned ion implantation area can also modulate the phase of the light beam at the interface. Reasonable design of the width, period and implantation depth of the ion beam implantation area as well as the implanted ions and ion concentration can well control the propagation direction of the light beam at the interface. By using ion implantation, the surface flatness of the first doped semiconductor layer 111 is not destroyed, and then as shown in FIG. Fig.26 As shown, the substrate is fixed to one side of the super-surface structure. In the process of bonding the substrate 10 to one side of the first doped semiconductor layer material, since the side of the first doped semiconductor layer material away from the active layer material is relatively flat, the bonding process has no effect on the nano-pattern area and does not affect the control effect of the nano-pattern on the light beam.

[0098] Or, if Fig. 27 As shown, different from the above embodiment, this embodiment can directly form a super surface structure on the substrate 10, which may specifically include: first forming a super surface structure layer 32 on the substrate 10; at this time, the material of the super surface structure layer 32 may be metal, preferably the same material as the first doped semiconductor layer; then, as Fig.28 As shown, the super surface structure layer 32 is etched to form a super surface structure; and then as shown Fig.29As shown, since the first doped semiconductor layer material needs to be grown later, it is necessary to ensure that the side of the super surface structure away from the substrate 10 is flat. The surface is flattened by forming a flattening layer 520 between the super surface structures 13. The preferred flattening layer only fills the groove formed by the super surface structure 13 and is flush with the super surface structure. However, due to process limitations, the flattening layer may cover the super surface structure 13. At this time, it can be ground by chemical grinding or mechanical grinding, so that the side of the LED structure away from the substrate is flat and the super surface structure is exposed. Subsequently, it can be further ground. Fig.11 and subsequent steps.

[0099] It should be noted that when making a metasurface structure, the etching depth and the refractive index of the material (colloid or flattening layer) filled in the groove can be adjusted so that the light output angle of each LED chip meets the requirements of the above-mentioned LED structure regarding the light output angle.

[0100] The embodiment of the present invention further provides a light field display system, which includes the LED structure and optical imaging lens provided in any embodiment of the present invention. The optical imaging lens can be, for example, a lens, etc. Since the light field display system includes the LED structure provided in any embodiment of the present invention, it also has the same beneficial effects, which will not be described in detail here.

[0101] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An LED structure, characterized in that: The LED structure comprises: substrate; A plurality of LED chips are disposed on the substrate, each of the LED chips comprising a first doped semiconductor layer, an active layer and a second doped semiconductor layer sequentially stacked on the substrate; An isolation groove is provided between the first doped semiconductor layers of any two adjacent LED chips, and the isolation groove is used to isolate the first doped semiconductor layers corresponding to the two adjacent LED chips; A light blocking structure is provided in each isolation groove, and the light blocking structure is used to block the light path between the first doped semiconductor layers corresponding to two adjacent LED chips; The LED chip also includes a first electrode arranged on a side of the second doped semiconductor layer away from the active layer; the light blocking structure is a conductive structure, and the light blocking structure is in contact with the adjacent first doped semiconductor layer; the light blocking structure is reused as the second electrode of the LED chip.

2. The LED structure according to claim 1, characterized in that: The first doped semiconductor layer is in a stepped shape including a first sublayer and a second sublayer; The size of the second sublayer is smaller than that of the first sublayer, the second sublayer is arranged on a side of the first sublayer away from the substrate, and the second sublayer exposes an edge region of a side of the first sublayer away from the substrate; The light blocking structure fills the isolation groove and covers at least a portion of the first sub-layer located in the edge area; Alternatively, the size of the active layer is smaller than the size of the first doped semiconductor layer on one side close to the active layer, and the active layer exposes an edge region of the first doped semiconductor layer; The light blocking structure fills the isolation trench and covers at least a portion of the first doped semiconductor layer located in the edge region.

3. The LED structure according to claim 1, characterized in that: The LED chip is also provided with a super surface structure.

4. The LED structure according to claim 3, characterized in that: The super surface structure corresponding to the LED chip is configured to adjust the light emitting direction of the LED chip to be offset toward the central area of ​​the LED structure.

5. The LED structure according to claim 3, characterized in that: A groove is formed on one side of the first doped semiconductor layer of the LED chip close to the substrate, and a portion of the first doped semiconductor layer close to the substrate forms the super-surface structure.

6. The LED structure according to claim 5, characterized in that: The first doped semiconductor layer and the substrate are fixed via colloid, and the colloid fills the groove.

7. The LED structure according to claim 3, characterized in that: The super surface structure is formed on a side of the first doped semiconductor layer of the LED chip close to the substrate.

8. The LED structure according to claim 3, characterized in that: A first ion implantation structure is formed on a portion of the first doped semiconductor layer of the LED chip close to the substrate, and the first ion implantation structure forms the super-surface structure.

9. The LED structure according to claim 1, characterized in that: A second ion implantation structure is disposed at the edge of the second doped semiconductor layer.

10. The LED structure according to claim 1, characterized in that: The LED chip also includes a first electrode arranged on a side of the second doped semiconductor layer away from the active layer; the first electrode is configured as follows: the center point of a side close to the second doped semiconductor layer is at the positive projection point of the first doped semiconductor layer close to the substrate side, and the angle between two line segments formed by the two points of the first electrode farthest from the side close to the second doped semiconductor layer is less than or equal to a preset value; the preset value is less than or equal to the light collection angle of the imaging device in the projection system.

11. The LED structure according to claim 1, characterized in that: An anti-total reflection film is arranged on a side of the substrate away from the LED chip.

12. A method for preparing an LED structure, characterized in that: The preparation method comprises: forming a substrate; A plurality of LED chips and light-blocking structures are formed, wherein each of the LED chips comprises a first doped semiconductor layer, an active layer and a second doped semiconductor layer sequentially stacked on the substrate; an isolation groove is provided between the first doped semiconductor layers of any two adjacent LED chips, and the isolation groove is used to isolate the first doped semiconductor layers corresponding to the two adjacent LED chips; a light-blocking structure is provided in each isolation groove, and the light-blocking structure is used to block the light path between the first doped semiconductor layers corresponding to the two adjacent LED chips; the LED chip further comprises a first electrode provided on a side of the second doped semiconductor layer away from the active layer; the light-blocking structure is a conductive structure, and the light-blocking structure is in contact with the adjacent first doped semiconductor layer; the light-blocking structure is reused as the second electrode of the LED chip.

13. The method for preparing an LED structure according to claim 12, characterized in that: The forming of a plurality of LED chips and a light blocking structure comprises: Epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material which are stacked in sequence; Etching the second doped semiconductor layer material and the active layer material to form an isolation hole, wherein the isolation hole exposes the first doped semiconductor layer material; Continue etching the first doped semiconductor layer material in the isolation hole to form the isolation groove; along the thickness direction of the LED structure, the orthographic projection of the isolation groove overlaps with the orthographic projection of the isolation hole; forming the light blocking structure in the isolation groove; Alternatively, epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material which are stacked in sequence; Etching the second doped semiconductor layer material and the active layer material to form an isolation hole, wherein the isolation hole exposes the first doped semiconductor layer material; The first doped semiconductor layer material is etched in the isolation hole to form the isolation groove, so that the isolation hole exposes the isolation groove and the edge area of ​​the first doped semiconductor layer of the LED chip; the light blocking structure is formed in the isolation hole and the isolation groove, wherein the light blocking structure fills the isolation groove and covers at least part of the first doped semiconductor layer located in the edge area; the light blocking structure is a conductive structure; Alternatively, epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material which are stacked in sequence; Etching the second doped semiconductor layer material, the active layer material and a portion of the first doped semiconductor layer material to form an isolation hole, wherein the isolation hole exposes the first doped semiconductor layer material that has not been etched; The first doped semiconductor layer material is etched in the isolation hole to form the isolation groove to form a stepped first doped semiconductor layer, the isolation hole exposes the isolation groove and the edge area of ​​the first doped semiconductor layer of the LED chip; the light blocking structure is formed in the isolation hole and the isolation groove, wherein the light blocking structure fills the isolation groove and covers at least a portion of the first doped semiconductor layer located in the edge area; the light blocking structure is a conductive structure.

14. The method for preparing an LED structure according to claim 12, characterized in that: The preparation method further comprises: before forming a plurality of LED chips and a light blocking structure, the method further comprises: A metasurface structure corresponding to each LED chip is formed.

15. The method for preparing an LED structure according to claim 14, characterized in that: The preparation method comprises: forming a first temporary substrate; epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material stacked in sequence on the first temporary substrate; bonding a second temporary substrate to one side of the second doped semiconductor layer material; removing the first temporary substrate to expose the first doped semiconductor layer material; Etching the first doped semiconductor layer material to form the super surface structure; Fixing the substrate to one side of the supersurface structure; and removing the second temporary substrate; Alternatively, the preparation method comprises: forming a first temporary substrate; epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material stacked in sequence on the first temporary substrate; bonding a second temporary substrate to one side of the second doped semiconductor layer material; removing the first temporary substrate to expose the first doped semiconductor layer material; Forming a super surface structure layer on a side of the first doped semiconductor layer material away from the active layer material; Etching the super surface structure layer to form the super surface structure; Fixing the substrate to one side of the supersurface structure; and removing the second temporary substrate; Alternatively, before forming the super-surface structure corresponding to each LED chip, the method includes: forming a first temporary substrate; epitaxially forming a first doped semiconductor layer material, an active layer material, and a second doped semiconductor layer material stacked in sequence on the first temporary substrate; bonding a second temporary substrate to one side of the second doped semiconductor layer material; removing the first temporary substrate to expose the first doped semiconductor layer material; Performing ion implantation on the first doped semiconductor layer material to form the super surface structure; Fixing the substrate to one side of the supersurface structure; and removing the second temporary substrate; Alternatively, the forming of the super surface structure comprises: forming the substrate; forming a super surface structure layer on the substrate; Etching the super surface structure layer material to form the super surface structure; The metasurface structure is planarized.

16. A light field display system, characterized in that: The light field display system comprises the LED structure and optical imaging lens described in any one of claims 1 to 11.

Images