Multicolor LED pixel unit and miniature LED display panel

Abstract

The invention discloses a multicolor LED pixel unit and a miniature LED display panel. The pixel unit (3000) comprises a substrate (100) and a light emitting transistor formed on the substrate (100). The light emitting transistor comprises a bottom conductive layer formed on the substrate (100) and a top conductive layer formed above the bottom conductive layer; an upper light emitting layer formed between the top conductive layer and the bottom conductive layer; at least one lower light emitting layer formed between the upper light emitting layer and the bottom conductive layer; and an electrical connector (303) electrically connecting the at least one lower light emitting layer and the bottom conductive layer.

Description

[0001] This patent application is a divisional application of Chinese Patent Application No. CN202080063585.5, filed on September 11, 2020, entitled “Multi-color LED pixel unit and micro LED display panel,” which entered the Chinese national phase on March 10, 2022, in accordance with the PCT Treaty. TECHNICAL FIELD

[0002] The present disclosure relates generally to the field of micro light emitting diode technology, and more specifically to multi-color LED pixel units and micro LED display panels. BACKGROUND

[0003] A light emitting diode (LED) is a semiconductor diode that can convert electrical energy into light energy. A conventional light emitting diode includes a P-N junction with unidirectional conduction. Under a positive bias, holes flow from the P region into the N region, and electrons flow from the N region into the P region, and the combination of the electrons in the N region and the holes in the P region produces spontaneous emission of excitation light. Electrons and holes have different energy states in different semiconductor materials, so the energy produced by the combination between the electrons and the holes is different. The higher the energy, the shorter the wavelength of the excitation light. Therefore, an LED can emit different light of different wavelengths from ultraviolet light to infrared light, thereby producing a multi-color LED.

[0004] Multi-color LEDs that emit white light or other colors of light have a wide range of applications, most of which are in the display field. Conventional LED display panels are formed by assembling single-color LEDs one by one on a substrate. The method for assembling single-color LEDs includes bonding the LEDs to an interconnection layer through the metal wires or connection electrodes of the LEDs using a metal bonding process or other processes. The process of assembling LEDs of other colors is not performed until the process of assembling single-color LEDs is completed, resulting in a complex process, increasing the processing difficulty, and increasing the production cost. In addition, multi-color display panels manufactured by assembling or forming individual LEDs one by one have high power consumption and reduced brightness and color. SUMMARY

[0005] According to one aspect of the present disclosure, a multi-color light emitting pixel unit is provided. The multi-color light emitting pixel unit includes a substrate and a light emitting transistor formed on the substrate. The light emitting transistor includes a bottom conductive layer formed on the substrate and a top conductive layer formed above the bottom conductive layer; an upper light emitting layer formed between the top conductive layer and the bottom conductive layer; at least one lower light emitting layer formed between the upper light emitting layer and the bottom conductive layer; and an electrical connector electrically connecting the at least one lower light emitting layer and the bottom conductive layer.

[0006] According to another aspect of the present disclosure, a micro display panel is provided. The micro display panel includes the multi-color light emitting pixel unit described above. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a cross-sectional view showing a multi-color light emitting pixel unit according to an embodiment of the present disclosure.

[0008] Figure 2 is a cross-sectional view showing a multi-color light emitting pixel unit according to an embodiment of the present disclosure.

[0009] Figure 3 is a cross-sectional view showing a multi-color light emitting pixel unit according to an embodiment of the present disclosure.

[0010] Figure 4 is a plan view of a multi-color light emitting pixel unit according to an embodiment of the present disclosure.

[0011] Figure 5 is a cross-sectional view showing a multi-color light emitting pixel unit according to an embodiment of the present disclosure.

[0012] Figure 6 is a flowchart showing details of a method of manufacturing the multi-color light emitting pixel unit shown in Figure 1 according to an embodiment of the present disclosure.

[0013] Figures 7 to 10 is a cross-sectional view showing a structure formed in a step of the method in Figure 6 according to an embodiment of the present disclosure.

[0014] Figure 11 is a flowchart showing details of step S601 in Figure 6 according to an embodiment of the present disclosure.

[0015] Figures 12 to 21 is a cross-sectional view showing a structure formed in a step of Figure 11 according to an embodiment of the present disclosure.

[0016] Figure 22 is a flowchart showing details of step S604 in Figure 6 according to an embodiment of the present disclosure.

[0017] Figures 23 to 25 is a cross-sectional view showing a structure formed in a step of Figure 22 according to an embodiment of the present disclosure.

[0018] Figure 26 and Figure 27is a cross-sectional view showing a structure formed in a process of manufacturing a first electrical connector according to an embodiment of the present disclosure.

[0019] Figure 28 is a cross-sectional view showing a multi-color light emitting pixel unit having a micro-gap structure according to an embodiment of the present disclosure.

[0020] Figure 29 is a flowchart showing a method of manufacturing a multi-color light emitting pixel unit shown in Figure 3 according to an embodiment of the present disclosure.

[0021] Figures 30 to 34 is a cross-sectional view showing a structure formed in a step of the method in Figure 29 according to an embodiment of the present disclosure.

[0022] Figure 35 is a flowchart showing details of a step S701 in Figure 29 according to an embodiment of the present disclosure.

[0023] Figure 36 is a cross-sectional view showing a micro-gap structure formed in three types of light emitting layers according to an embodiment of the present disclosure.

[0024] Figure 37 is a flowchart showing details of a step S705 in Figure 29 according to an embodiment of the present disclosure.

[0025] Figures 38 to 40 is a cross-sectional view showing a structure formed in a step in Figure 37 according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0026] Reference will now be made in detail to the preferred embodiments of the application, examples of which are illustrated in the accompanying drawings. The detailed description

[0027] Hereinafter, the present disclosure will be further described by embodiments of the present disclosure with reference to Figures 1 to 40 . It should be noted that all the drawings are in a very simplified form and not according to the precise proportions. Only the features necessary for facilitating and clearly explaining the embodiments of the present disclosure are shown.

[0028] The multi-color light emitting pixel unit disclosed herein includes at least one type of light emitting transistor, or several types of light emitting transistors. The various types of light emitting transistors include an upper conductive layer, a bottom conductive layer, and a light emitting layer between the upper conductive layer and the bottom conductive layer. All of the light emitting transistors share the same upper conductive layer and the same bottom conductive layer. It should be noted that the light emitting layer can be a single layer or multiple layers. An intermediate layer can be arranged between two light emitting layers in the same light emitting diode. It is assumed that the multi-color light emitting pixel unit includes first to Mth types of light emitting transistors, where M is an integer and is not less than two. Each of the first to Mth types of light emitting transistors includes at least the same type of light emitting layer. For example, each of the first to Mth types of light emitting transistors includes a first type of light emitting layer. Any one of the second to Mth types of light emitting layers is different from the first type of light emitting layer. The present disclosure also provides a micro display panel including a plurality of the above-described pixel units arranged in a matrix.

[0029] In some embodiments, the light emitting transistor can be at least one of a light emitting diode (LED), a Schottky light emitting transistor, etc. The top conductive layer of the light emitting transistor is, but is not limited to, a transparent conductive layer, and the bottom conductive layer of the light emitting transistor is, but is not limited to, a metal layer. Hereinafter, the LED is used as an example of the light emitting transistor, but this does not limit the scope of the present disclosure. The LED can be changed into another light emitting transistor by those skilled in the art according to conventional technical means.

[0030] Figure 1 is a cross-sectional view showing a multi-color light emitting pixel unit 1000 according to an embodiment of the present disclosure. Referring to Figure 1 , the multi-color light emitting pixel unit 1000 includes at least a first type of LED 01 and a second type of LED 02 arranged side by side on a substrate 100. The top of the first type of LED 01 is not in the same horizontal plane as the top of the second type of LED 02. The type of the first type of LED 01 is different from the type of the second type of LED 02. Here, as Figure 1As shown, the top of the first type of LED 01 is lower than the top of the second type of LED 02. According to embodiments, the first type of LED 01 is selected from one of a red LED, a green LED, a blue LED, a yellow LED, an orange LED, or a cyan LED, and the second type of LED 02 is selected from one of a green LED, a blue LED, a red LED, a yellow LED, an orange LED, or a cyan LED. Further, the size of the light emitting area of the first type of LED 01 is different from the size of the light emitting area of the second type of LED 02. For example, the first type of LED 01 is a red LED, the second type of LED 02 is a green LED, and the size of the light emitting area of the red LED is different from the size of the light emitting area of the green LED. Further, the light emitting area of the green LED can be smaller than the light emitting area of the red LED according to different colors that can be required.

[0031] Further, the isolation structure 07 is arranged between the first type of LED and the second type of LED. In the embodiment shown in Figure 1 In the embodiment shown in FIG. 1, the isolation structure 07 between the first type of LED 01 and the second type of LED 02 is an isolation trench. The multi-color light emitting pixel unit 1000 includes a first metal layer, a first type of light emitting layer, a second metal layer, and a second type of light emitting layer. As shown in FIG. 1, the first type of light emitting layer is arranged on the first metal layer, and the second type of light emitting layer is arranged on the second metal layer. The first type of light emitting layer and the second type of light emitting layer are arranged on the isolation trench. Figure 1As shown in FIG. 1, the first type of LED 01 includes at least a first segment 101-1 of a first metal layer and a first segment 102-1 of a first type of light emitting layer in a bottom-up order. The first segment 101-1 of the first metal layer constitutes a bottom conductive layer of the first type of LED 01. The second type of LED 02 includes at least a second segment 101-2 of the first metal layer, a second segment 102-2 of the first type of light emitting layer, a first segment 201-1 of a second metal layer, a first segment 202-2 of a second type of light emitting layer, and a first electrical connector 203 in a bottom-up order. The first segment 101-1 of the first metal layer and the second segment 101-2 of the first metal layer are electrically connected to the substrate 100. The isolation structure 07 isolates the first segment 101-1 of the first metal layer in the first type of LED 01 from the second segment 101-2 of the first metal layer in the second type of LED 02. The isolation structure 07 also isolates the first segment 102-1 of the first type of light emitting layer in the first type of LED 01 from the second segment 102-2 of the first type of light emitting layer in the second type of LED 02. In addition, to simplify the manufacturing process, the first segment 201-1 of the second metal layer, the second segment 102-2 of the first type of light emitting layer, and the second segment 101-2 of the first metal layer in the second type of LED 02 are electrically connected to each other by the first electrical connector 203. According to an embodiment, the first electrical connector 203 can be attached to and contact a portion or all of the sidewall surface of the second type of LED 02. Alternatively, the first electrical connector 203 can be attached to and contact only the surfaces of the first segment 201-1 of the second metal layer and the second segment 101-2 of the first metal layer in the second type of LED 02. Or alternatively, the first electrical connector 203 can be formed as a conductive side arm attached to and contacting the sidewalls of the first segment 201-1 of the second metal layer, the second segment 102-2 of the first type of light emitting layer, and the second segment 101-2 of the first metal layer. The electrical connector 203 between the second segment 101-2 of the first metal layer and the first segment 201-1 of the second metal layer in the second type of LED 02 can have other shapes, such as a curve. In the embodiment shown in FIG. 1, the first electrical connector 203 is attached to the sidewall of the second type of LED 02 such that the first electrical connector 203 follows the surface topography of the sidewall of the second type of LED 02. Figure 1 In the embodiment shown in FIG. 1, the first electrical connector 203 is attached to the sidewall of the second type of LED 02 such that the first electrical connector 203 follows the surface topography of the sidewall of the second type of LED 02.

[0032] Referring to Figure 1A top insulating layer 04 and a top transparent conductive layer 05 are disposed on a first segment 102-1 of a first-type light-emitting layer in a first-type LED 01 and a first segment 202-1 of a second-type light-emitting layer in a second-type LED 02. The top insulating layer 04 covers the first segment 102-1 of the first-type light-emitting layer, the first segment 202-1 of the second-type light-emitting layer, and the exposed substrate 100. The top insulating layer 04 has an opening that exposes portions of the top surfaces of the first segment 102-1 of the first-type light-emitting layer and the first segment 202-1 of the second-type light-emitting layer. The top transparent conductive layer 05 covers the top insulating layer 04 and is formed in the opening of the top insulating layer 04, thereby contacting the exposed top surfaces of the first segment 102-1 of the first-type light-emitting layer and the first segment 202-1 of the second-type light-emitting layer via the opening.

[0033] Substrate 100 is an integrated circuit (IC) substrate. The IC substrate includes an interconnect layer electrically connected to a first segment 101-1 of a first metal layer in a first type of LED 01 and a second segment 101-2 of a first metal layer in a second type of LED 02. Since a first electrical connector 203 is connected to the second segment 101-2 of the first metal layer in the second type of LED 02, the first electrical connector 203 is also connected to the interconnect layer in substrate 100. Furthermore, referring to… Figure 1 The bottom of the first electrical connector 203 extends to the substrate 100 to connect with the interconnect layer. Here, the IC substrate includes at least a driving circuit. The driving circuit controls each LED individually.

[0034] Figure 2 This is a cross-sectional view showing a multicolor luminescent pixel unit 2000 according to an embodiment of this disclosure. (Refer to...) Figure 2 The multi-color light-emitting pixel unit 2000 includes at least a first-type LED 01, a second-type LED 02, and a third-type LED 03 arranged on the same substrate 100. The third-type LED 03 is different from the first-type LED 01 and the second-type LED 02. Here, the first-type LED 01 is selected from one of red LEDs, green LEDs, blue LEDs, yellow LEDs, orange LEDs, or cyan LEDs; the second-type LED 02 is selected from one of green LEDs, blue LEDs, red LEDs, yellow LEDs, orange LEDs, or cyan LEDs; and the third-type LED 03 is selected from one of blue LEDs, red LEDs, green LEDs, yellow LEDs, orange LEDs, or cyan LEDs. For example, a red LED is selected as the first-type LED 01, a green LED is selected as the second-type LED 02, and a blue LED is selected as the third-type LED 03. (Refer to...) Figure 2The height of the third type of LED 03 is different from the height of the first type of LED 01. In addition, the height of the first type of LED 01 is different from the height of the second type of LED 02, and the height of the second type of LED 02 is the same as the height of the third type of LED 03. In other embodiments, the height of the third type of LED 03, the height of the first type of LED 01, and the height of the second type of LED 02 can be different from each other, as shown in Figure 3

[0035] In the multi-color light emitting pixel unit 2000, the structures of the first type of LED 01 and the second type of LED 02 are the same as those of the first type of LED 01 and the second type of LED 02 in the multi-color light emitting pixel unit 2000, and thus the detailed description thereof is not repeated. The third type of LED 03 in the multi-color light emitting pixel unit 2000 includes at least the third segment 101-3 of the first metal layer, the third segment 102-3 of the first type of light emitting layer, the first segment 301-1 of the third metal layer, and the first segment 302-1 of the third type of light emitting layer, in the order from bottom to top, and the second electrical connector 303 connecting the third segment 101-3 of the first metal layer and the first segment 301-1 of the third metal layer. The multi-color light emitting pixel unit 2000 further includes a top isolation layer 04 covering the first type of LED 01, the second type of LED 02, and the third type of LED 03 and having an opening exposing a portion of the first segment of the first type of light emitting layer 102-1 in the first type of LED 01, a portion of the first segment 202-1 of the second type of light emitting layer, and a portion of the first segment 302-1 of the third type of light emitting layer. A top electrode layer 05 is formed on top of the top isolation layer 04 and contacts the first segment 102-1 of the first type of light emitting layer, the first segment 202-1 of the second type of light emitting layer, and the first segment 302-1 of the third type of light emitting layer via the opening of the top isolation layer 04.

[0036] Figure 3 is a cross-sectional view showing a multi-color light emitting pixel unit 3000 according to an embodiment of the disclosure. Referring to Figure 3 In the multi-color light emitting pixel unit 3000, the top of the third type of LED 03 is higher than the top of the second type of LED 02, while the height of the first type of LED is different from the height of the second type of LED 03.

[0037] Figure 4 is a top view of a multi-color light emitting pixel unit 4000 according to an embodiment of the disclosure. The multi-color light emitting pixel unit 4000 can be the multi-color light emitting pixel unit 2000 or Figure 2 the multi-color light emitting pixel unit 3000 shown in​Figure 3 The multicolor light-emitting pixel unit 3000 shown in the middle. Figure 4 Three types of LEDs 01, 02 and 03 are shown in the arrangement of the pixel unit, but the present disclosure also includes other arrangements, such as a matrix. Here, the size of the light-emitting area of the third type of LED 03 is different from the size of the light-emitting area of the first type of LED 01, and is different from the size of the light-emitting area of the second type of LED 02. For example, the first type of LED 01 is a red LED, the second type of LED 02 is a green LED, and the third type of LED 03 is a blue LED. The size of the light-emitting area of each of the first type of LED 01, the second type of LED 02, and the third type of LED 03 can be determined according to the color of light that the multicolor light-emitting pixel unit 4000 needs to emit. When white light is needed, the size of the light-emitting area of the red LED is greater than the size of the light-emitting area of the green LED, and the size of the light-emitting area of the blue LED is greater than the size of the light-emitting area of the green LED. As shown, the space between the red LED and the blue LED is greater than the space between the blue LED and the green LED; the space between the red LED and the green LED is greater than the space between the blue LED and the green LED, thereby achieving a better light-emitting effect. Figure 4

[0038] Referring back to Figure 3 , the isolation structure 07 is arranged between two of the first type of LED 01, the second type of LED 02, and the third type of LED 03. The isolation structure is an isolation trench. The first type of LED 01, the second type of LED 02, and the third type of LED 03 are formed by the first metal layer 101, the first type of light-emitting layer 102, the second metal layer 201, the second type of light-emitting layer 202, the third metal layer 301, and the third type of light-emitting layer 302. Figure 3 The first type of LED 01 and the second type of LED 02 in Figure 2 are the same as the first type of LED 01 and the second type of LED 02 in Figure 3 ​As shown in the middle, the first type of LED 01 includes at least a first section 101-1 of the first metal layer and a first section 102-1 of the first type of light emitting layer in a lower-to-upper order. The second type of LED 02 includes at least a second section 101-2 of the first metal layer, a second section 102-2 of the first type of light emitting layer, a first section 201-1 of the second metal layer, and a first section 202-1 of the second type of light emitting layer, and a first electrical connector 203 in a lower-to-upper order. The third type of LED 03 includes at least a third section 101-3 of the first metal layer, a third section 102-3 of the first type of light emitting layer, a second section 201-2 of the second metal layer, a second section 202-2 of the second type of light emitting layer, a first section 301-1 of the third metal layer, and a first section 302-1 of the third type of light emitting layer, and a second electrical connector 303 in a lower-to-upper order. As shown in the right, the fourth type of LED 04 includes at least a first section 101-4 of the first metal layer, a first section 102-4 of the first type of light emitting layer, a second section 201-3 of the second metal layer, a second section 202-2 of the second type of light emitting layer, a first section 301-2 of the third metal layer, and a first section 302-2 of the third type of light emitting layer, and a third electrical connector 303 in a lower-to-upper order. Figure 3As shown, the first segment 101-1 of the first metal layer, the second segment 101-2 of the first metal layer, and the third segment 101-3 of the first metal layer are electrically connected with the substrate 100. The first electrical connector 203 in the second type of LED 02 electrically connects the first segment 201-1 of the second metal layer with the second segment 101-2 of the first metal layer. The second electrical connector 303 in the third type of LED 03 electrically connects the first segment 301-1 of the third metal layer with the second segment 201-2 of the second metal layer and the third segment 101-3 of the first metal layer. The isolation structure 07 isolates the first segment 101-1 of the first metal layer in the first type of LED 01 from the second segment 101-2 of the first metal layer in the second type of LED 02 and the third segment 101-3 of the first metal layer in the third type of LED 03, isolates the first segment 102-1 of the first type of light-emitting layer in the first type of LED 01 from the second segment 102-2 of the first type of light-emitting layer in the second type of LED 02 and the third segment 102-3 of the first type of light-emitting layer in the third type of LED 03, isolates the first segment 201-1 of the second metal layer in the second type of LED 02 from the second segment 201-2 of the second metal layer in the third type of LED 03, and isolates the first segment 202-1 of the second type of light-emitting layer in the second type of LED 02 from the second segment 202-2 of the second type of light-emitting layer in the third type of LED 03. It should be noted that the first electrical connector 203 is used to connect the second segment 102-2 of the first type of light-emitting layer in the second type of LED 02 with the second segment 101-2 of the first metal layer, while the second electrical connector 303 is used to connect the second segment 202-2 of the second type of light-emitting layer and the third segment 102-3 of the first type of light-emitting layer in the third type of LED 03 with the third segment 101-3 of the first metal layer. Therefore, in order to simplify the manufacturing process, the first electrical connector 203 and the second electrical connector 303 are used to connect the second segment 102-2 of the first type of light-emitting layer in the second type of LED 02 with the second segment 101-2 of the first metal layer and the second segment 202-2 of the second type of light-emitting layer in the third type of LED 03 with the third segment 101-3 of the first metal layer, respectively. Figure 1In the same manner, the first electrical connector 203 also connects the second segment 102-2 of the first type of light emitting layer with the second segment 101-2 of the first metal layer. That is, in the second type of LED 02, the first electrical connector 203 connects the first segment 201-1 of the second metal layer and the second segment 102-2 of the first type of light emitting layer with the second segment 101-2 of the first metal layer. The second electrical connector 303 also connects the second segment 202-2 of the second type of light emitting layer with the third segment 101-3 of the first metal layer. That is, in the third type of LED 03, the second electrical connector 303 connects the first segment 301-1 of the third metal layer, the second segment 202-2 of the second type of light emitting layer, and the second segment 201-2 of the second metal layer with the third segment 101-3 of the first metal layer. Alternatively, the second electrical connector 303 also connects the second segment 202-2 of the second type of light emitting layer and the third segment 102-3 of the first type of light emitting layer with the third segment 101-3 of the first metal layer. That is, in the third type of LED 03, the second electrical connector 303 connects the first segment 301-1 of the third metal layer, the second segment 202-2 of the second type of light emitting layer, the second segment 201-2 of the second metal layer, and the third segment 102-3 of the first type of light emitting layer with the third segment 101-3 of the first metal layer. Furthermore, the bottom of the first electrical connector 203 and the bottom of the second electrical connector 303 each and directly contact the substrate 100, thereby simplifying the manufacturing process. It should be noted that the materials of the first electrical connector 203 and the second electrical connector 303 are formed of an electrically conductive metal. In embodiments, the second electrical connector 303 is attached to and contacts the sidewall surface of the third type of LED 03.

[0039] In one embodiment, the first type of light emitting layer is a red light emitting layer, the second type of light emitting layer is a green light emitting layer, and the third type of light emitting layer is a blue light emitting layer, the first type of LED 01 is a red LED 01, the second type of LED 02 is a green LED 02, and the third type of LED 03 is a blue LED 03. In the red LED 01, the voltage applied between the top transparent conductive layer 05 and the first segment 101-1 of the first metal layer is applied to the first segment 102-1 of the red light emitting layer. Thus, the first segment 102-1 of the red light emitting layer in the red LED 01 emits red light. In the green LED 02, the first electrical connector 203 electrically connects the second segment 102-2 of the red light emitting layer with the second segment 101-2 of the first metal layer, such that the voltage applied between the top transparent conductive layer 05 and the second segment 101-2 of the first metal layer is applied only to the first segment 202-1 of the green light emitting layer. Thus, only the first segment 202-1 of the green light emitting layer in the green LED 02 emits green light, while the second segment 102-2 of the red light emitting layer in the green LED 02 does not emit light. In the third type of LED 03, the second electrical connector 303 electrically connects the third segment 102-3 of the red light emitting layer and the second segment 202-2 of the green light emitting layer with the third segment 101-3 of the first metal layer, such that the voltage applied between the top transparent conductive layer 05 and the third segment 101-3 of the first metal layer is applied only to the first segment 302-1 of the blue light emitting layer. Thus, only the first segment 302-1 of the blue light emitting layer in the blue LED 03 emits blue light, while the third segment 102-3 of the red light emitting layer and the second segment 202-2 of the green light emitting layer in the blue LED 03 do not emit light.

[0040] Referring again to Figure 3 , a top isolation layer 04 and a top transparent conductive layer 05 are disposed on the first type of LED 01, the second type of LED 02, and the third type of LED 03. The top isolation layer 04 covers the first segment 102-1 of the first type of light emitting layer, the first segment 202-1 of the second type of light emitting layer, the first segment 302-1 of the third type of light emitting layer, and the exposed substrate 100. An opening is disposed in the top isolation layer 04 to expose portions of the top surfaces of the first segment 102-1 of the first type of light emitting layer, the first segment 202-1 of the second type of light emitting layer, and the first segment 302-1 of the third type of light emitting layer. The top transparent conductive layer 05 covers the top isolation layer 04 and is formed in the opening of the top isolation layer 04, thereby contacting the exposed top surface of the first segment 102-1 of the first type of light emitting layer, the exposed top surface of the first segment 202-1 of the second type of light emitting layer, and the exposed top surface of the first segment 302-1 of the third type of light emitting layer.

[0041] Detailed description of the substrate 100 in the multi-color light emitting pixel unit 3000 having at least three types of LEDs corresponds to the description of Figure 1 and will not be repeated here. It should be noted that the interconnection layer in the IC substrate 100 is electrically connected with the first type of LED 01, the second type of LED 02 and the third type of LED 03. The driving circuit in the IC substrate 100 controls each LED respectively.

[0042] In the multi-color light emitting pixel units 1000 to 4000 in Figures 1 to 4 , one or more of the light emitting layers 102, 202 and 302 can have a micro-gap structure. For example, in the multi-color light emitting pixel unit 1000 shown in Figure 1 , the first type of light emitting layer 102 can have a micro-gap structure, or the second type of light emitting layer 202 can have a micro-gap structure, or both the first type of light emitting layer 102 and the second type of light emitting layer 202 can have a micro-gap structure. As another example, in the multi-color light emitting pixel unit 3000 shown in Figure 3 , the first type of light emitting layer 102 can have a micro-gap structure, or the second type of light emitting layer 202 can have a micro-gap structure, or the third type of light emitting layer 302 can have a micro-gap structure, or both the first type of light emitting layer 102 and the second type of light emitting layer 202 can have a micro-gap structure, or both the second type of light emitting layer 202 and the third type of light emitting layer 302 can have a micro-gap structure, or both the first type of light emitting layer 102 and the third type of light emitting layer 302 can have a micro-gap structure, or all of the first type of light emitting layer 102, the second type of light emitting layer 202 and the third type of light emitting layer 302 can have a micro-gap structure. Here, Figures 1 to 3 Each of the micro-gap structures in the multi-color light emitting pixel units 1000 to 3000 shown in

[0043] Figure 5 is a cross-sectional view showing a multi-color light emitting pixel unit 5000 according to an embodiment of the present disclosure. As Figure 5As shown, each of the first type of light emitting layer 102, the second type of light emitting layer 202, and the third type of light emitting layer 302 can have a plurality of microcavity structures 06. Each of the microcavity structures 06 extends along a direction perpendicular to the substrate 100 and passes through a corresponding light emitting layer, such as the first type of light emitting layer 102, the second type of light emitting layer 202, or the third type of light emitting layer 302. When multiple light emitting layers are used in an embodiment, the microcavity structures 06 are arranged in at least one light emitting layer, preferably in the top light emitting layer.

[0044] Still referring to Figure 5 , the microcavity structures 06 are staggered with respect to each other in the multiple light emitting layers. That is, the microcavity structures 06 in the first type of light emitting layer 102 are not vertically aligned with the microcavity structures 06 in the second type of light emitting layer 202, and the microcavity structures 06 in the second type of light emitting layer 202 are not vertically aligned with the microcavity structures 06 in the third type of light emitting layer 302. In each of the second type of LED 02 and the third type of LED 03, the microcavity structures in the first type of light emitting layer 102 are isolated and sealed between the second metal layer 201 on top of the first type of light emitting layer 102 and the first metal layer 101 on the bottom thereof. In the third type of LED 03, the microcavity structures 06 in the second type of light emitting layer 202 are isolated and sealed between the third metal layer 301 on top of the second light emitting layer 202 and the second metal layer 201 on the bottom thereof, and the microcavity structures 06 in the third type of light emitting layer 302 are isolated and sealed between the top isolation layer 04 on top of the third type of light emitting layer 302 and the third metal layer 301 on the bottom thereof.

[0045] In a similar manner, in a multi-color light emitting pixel unit including first through Mth type of LEDs in another embodiment of the present disclosure, the Mth type of LED has M light emitting layers, and a metal layer is arranged on the bottom of each light emitting layer, where M is a positive integer and is greater than or equal to the number two. In each of the first through Mth type of LEDs, a top conductive layer (as an upper conductive layer) is arranged on top of the top light emitting layer, such that the microcavity structures in the top light emitting layer can be isolated and sealed between the top conductive layer and the metal layer on the bottom of the top light emitting layer. The microcavity structures in each light emitting layer are isolated and sealed between the metal layers on the top and bottom of the respective light emitting layer, respectively.

[0046] Further, similar to Figures 1 to 4The multicolor light emitting pixel unit 1000 to 4000 in the multicolor light emitting pixel unit 1000 to 4000 in the multicolor light emitting pixel unit according to another embodiment of the present disclosure includes a plurality of LEDs (including a first type of LED to an Mth type of LED). The Mth type of LED includes at least all the light emitting layers and metal layers configured in the (M-1)th type of LED and an Mth light emitting layer and an Mth metal layer. On this basis, the Mth type of LED has an (M-1)th electrical connector connected to the Mth metal layer, the (M-1)th metal layer, and the first metal layer. In addition, the (M-1)th electrical connector can be connected to the Mth metal layer, the (M-1)th type of light emitting layer, the (M-1)th metal layer, the first type of light emitting layer, and the first metal layer. The arrangement of the (M-1)th electrical connector can refer to the description of the first electrical connector 203 in the multicolor light emitting pixel unit 1000 to 4000 in the multicolor light emitting pixel unit according to another embodiment of the present disclosure. The first to (M-1)th electrical connectors connect the first to Mth metal layers, and the first to (M-1)th electrical connectors can directly contact the substrate and the first metal layer. Herein, there is a difference from the first type of LED to the Mth type of LED. In addition, each type of LED can be selected from a red LED, a green LED, a blue LED, a yellow LED, an orange LED, a purple LED, or a cyan LED. Herein, the different color LEDs are conventional LEDs, which are known to those skilled in the art, and will not be described herein. In addition, the first type of LED to the Mth type of LED are spaced apart on the same substrate. The top isolation layer covers the exposed surface of the substrate and the exposed surface of the first to Mth type of LED. The top isolation layer of each type of LED has an opening thereof, and the transparent conductive layer covers the surface of the top isolation layer and is filled in the opening, wherein the transparent conductive layer at the bottom of the opening is in electrical contact with the top light emitting layer of each type of LED. Refer to the description of the multicolor light emitting pixel unit 1000 to 4000 in the multicolor light emitting pixel unit according to another embodiment of the present disclosure. Figure 1 Figure 4 Figure 5 In the pixel unit with M types of LEDs, the size of the light emitting area of the first to Mth type of LED is different from each other. According to the arrangement of the LEDs in the pixel unit, the size of the light emitting area of the first type of LED is larger than the size of the light emitting area of the other types of LEDs. Alternatively, the first type of LED is a red LED, and the size of the light emitting area of the first type of LED is larger than the size of the light emitting area of the other types of LEDs. Alternatively, the other types of LEDs include at least a green LED or a blue LED.

[0047] A multicolor micro display panel according to an embodiment of the present disclosure is also provided. The micro display panel includes a plurality of multicolor pixel units arranged in a matrix. The multicolor pixel unit herein can be the LED pixel unit described above.

[0048] The method of manufacturing the multicolor light emitting pixel unit will be further described below in conjunction with the accompanying drawings.

[0049] ​​Figure 6 is a flowchart showing a method of manufacturing a multi-color light emitting pixel unit according to an embodiment of the present disclosure. Figure 1 is a flowchart showing a method of manufacturing a multi-color light emitting pixel unit according to an embodiment of the present disclosure. Figures 7 to 10 is a cross-sectional view of a structure formed in the steps shown in Figure 6 , manufacturing a multi-color light emitting pixel unit as shown in Figure 6 , manufacturing a multi-color light emitting pixel unit as shown in Figure 1 A method of manufacturing a multi-color light emitting pixel unit as shown in

[0050] In step S601, referring to Figure 7 , a stack structure including a first metal layer 101, a first type of light emitting layer 102, a second metal layer 201, and a second type of light emitting layer 202 is formed on the substrate 100 from bottom to top. In other words, the first type of light emitting layer 102 and the second type of light emitting layer 202 are stacked on the substrate 100 from bottom to top. The first metal layer 101 is formed at the bottom of the first type of light emitting layer 102. The second metal layer 201 is formed at the bottom of the second type of light emitting layer 202. The second metal layer 201 is arranged between the first type of light emitting layer 102 and the second light emitting layer 202.

[0051] More specifically, the substrate 100 can be, but is not limited to, an IC substrate.

[0052] Figure 11 is a flowchart showing details of step S601 in Figure 6 is a flowchart showing details of step S601 in Figures 12 to 21 is a cross-sectional view of a structure formed in the steps shown in Figure 11 , manufacturing a multi-color light emitting pixel unit as shown in Figure 11 , step S601 further includes the following specific steps.

[0053] In step S101, referring to Figure 12 , a first metal bonding layer M01 is formed on the substrate 100, a first type of light emitting layer 102 is formed on a first base B1, and a second metal bonding layer M02 is formed on the top of the first type of light emitting layer 102.

[0054] More specifically, the first metal bonding layer M01 can be prepared by, but is not limited to, physical vapor deposition (such as evaporation, sputtering, etc.). The material of the first base B1 is designed according to the first type of light emitting layer 102. For example, the first base B1 can be a gallium nitride (GaN) base. The first type of light emitting layer 102 can be formed by, but is not limited to, epitaxial growth on the first base B1. The second metal bonding layer M02 can be prepared by, but is not limited to, physical vapor deposition (such as evaporation).

[0055] In step S102,Figure 12 Referring to Figure 13 The first substrate B1 is inverted upside down so that the second metal bonding layer M02 faces the first metal bonding layer M01, and then the second metal bonding layer M02 is bonded with the first metal bonding layer M01 to form the first metal layer 101.

[0056] In step S103, in combination Figure 13 Referring to Figure 14 The first substrate B1 is removed.

[0057] Here, after the first substrate B1 is removed, referring to Figure 15 Step S103 can further include: thinning the first type of light emitting layer 102.

[0058] Further, according to an embodiment, after the first substrate B1 is removed or the first type of light emitting layer 102 is thinned, and before the third metal bonding layer is formed, referring to Figure 16 Step S103 can further include: forming a micro-gap structure 06 in the first type of light emitting layer 102. The micro-gap structure 06 is formed by, but not limited to, photolithography and etching. In photolithography, a photolithography pattern is designed according to the size of the micro-gap structure 06. According to an embodiment, the cross-sectional size of the micro-gap structure pattern is no more than 2 nm. Here, the cross-sectional size of the air gap can be the diameter of the cross-section of the air gap, or the length or width of the cross-section of the air gap.

[0059] In step S104, referring to Figure 17 The third metal bonding layer M03 is formed on the first type of light emitting layer 102, the second type of light emitting layer 202 is formed on the second substrate B2, and the fourth metal bonding layer M04 is formed on top of the second type of light emitting layer 202.

[0060] In step S105, in combination Figure 17 Referring to Figure 18 The second substrate B2 is inverted upside down so that the fourth metal bonding layer M04 faces the third metal bonding layer M03, and the fourth metal bonding layer M04 is bonded with the third metal bonding layer M03 to form the second metal layer 201.

[0061] In step S106, in combination Figure 18 Referring to Figure 19 The second substrate B2 is removed.

[0062] Here, after the second substrate B2 is removed, referring to Figure 20 In step S106, the second type of light emitting layer 202 is thinned.

[0063] According to the embodiments, after the second substrate B2 is removed or the second type of light emitting layer 202 is thinned, refer to Figure 21 In step S106, the micro-gap structure 06 is formed in the second type of light emitting layer 202. The micro-gap structure 06 is formed by a process similar to that of forming the micro-gap structure 06 in the first type of light emitting layer 102. Therefore, the process of forming the micro-gap structure 06 in the second type of light emitting layer 202 will not be repeated.

[0064] Referring back to Figures 6 to 10 The process after step S601 according to the embodiments of the present disclosure will be further described hereinafter.

[0065] In step S602, refer to Figure 8 The second type of light emitting layer 202 and the second metal layer 201 are patterned until a portion of the top of the first type of light emitting layer 102 is exposed, thereby forming a step structure made of the second type of light emitting layer 202 on the first type of light emitting layer 102.

[0066] More specifically, the process of patterning the second type of light emitting layer 202 and the second metal layer 201 can be performed by photolithography and plasma etching. The process of patterning the second type of light emitting layer 202 and the second metal layer 201 also includes over-etching the top of the first type of light emitting layer 102. The parameters of the patterning process can be set according to actual needs, which will not be limited here.

[0067] In step S603, refer to Figure 9 According to the preset first type of light emitting area A01 and the preset second type of light emitting area A02, the second type of light emitting layer 202, the second metal layer 201, the first type of light emitting layer 102 and the first metal layer 101 are etched, thereby dividing the first type of light emitting layer 102 in the first type of light emitting area A01 from the first type of light emitting layer 102 in the second type of light emitting area A02, and dividing the first metal layer 101 in the first type of light emitting area A01 from the first metal layer 101 in the second type of light emitting area A02. As a result of step S603, the first type of LED 01 including the first segment 101-1 of the first metal layer and the first segment 102-1 of the first type of light emitting layer, and the second type of LED 02 including the second segment 101-2 of the first metal layer, the second segment 102-2 of the first type of light emitting layer, the first segment 201-1 of the second metal layer and the second segment 202-1 of the second type of light emitting layer are formed.

[0068] Here, the process of etching the second type of light emitting layer 202, the second metal layer 201, the first type of light emitting layer 102, and the first metal layer 101 is performed by photolithography and etching. The parameters of the etching process can be set according to actual needs.

[0069] According to embodiments, as a result of step S603, the plurality of multi-color light emitting pixel units are divided from each other according to the preset pixel unit array. In this way, the light emitting transistors in the pixel units and / or the pixel unit array can be prepared by one division step, which simplifies the process and reduces the production cost, especially facilitates mass production.

[0070] In step S604, referring to Figure 10 , a shared top electrode layer 05 serving as an extraction electrode of the second metal layer 201 is formed on the top of the first section 102-1 of the first type of light emitting layer and the first section 202-1 of the second type of light emitting layer in the second type of light emitting region A02.

[0071] Figure 22 is a flowchart showing details of step S604 in Figure 6 according to embodiments of the present disclosure. Figures 23 to 25 is a cross-sectional view showing the structure formed in the steps shown in Figure 22 according to embodiments of the present disclosure. Referring to Figure 22 , the specific process of step S604 includes the following steps.

[0072] In step S401, referring to Figure 23 , a portion of the first section 202-1 of the second type of light emitting layer is removed, thereby exposing a portion of the first section 201-1 of the second metal layer.

[0073] In step S402, referring to Figure 24 , a first electrical connector 203 is formed on the sidewall and top of the first section 201-1 of the second metal layer in the second type of light emitting region A02, on the sidewall of the second section 102-2 of the first type of light emitting layer, and on the sidewall of the second section 101-2 of the first metal layer.

[0074] Figures 26 to 27 is a cross-sectional view showing the structure formed in the steps of manufacturing the first electrical connector 203 according to embodiments of the present disclosure. In step S402, the first electrical connector 203 is formed by the following specific steps.

[0075] In step S4021, referring to Figure 24 , a first electrical connector 203 is formed on the sidewall and top of the first section 201-1 of the second metal layer in the second type of light emitting region A02, on the sidewall of the second section 102-2 of the first type of light emitting layer, and on the sidewall of the second section 101-2 of the first metal layer. Figure 26forming a mask Y to shield the area without the first electrical connector 203, thereby exposing the top and sidewall of the first segment 201-1 of the second metal layer in the second type of light emitting region A02, the sidewall of the second segment 102-2 of the first type of light emitting layer, and the sidewall of the second segment 101-2 of the first metal layer.

[0076] In step S4022, with reference to Figure 27 After completing step S4021, a conductive material 203’ is deposited on the substrate 100.

[0077] In step S4023, with reference to Figure 10 The mask Y and the conductive material 203’ on the mask Y are removed, thereby forming the first electrical connector 203 on the top and sidewall of the first segment 201-1 of the second metal layer in the second type of light emitting region A02, on the sidewall of the second segment 102-2 of the first type of light emitting layer, and on the sidewall of the second segment 101-2 of the first metal layer.

[0078] The process of fabricating the shared top electrode layer 05 will be further described in the following.

[0079] In step S403, with reference to Figure 25 A separation layer 04 is formed to cover the first type of light emitting region A01, the second type of light emitting region A02, and the surface of the exposed substrate 100. The separation layer 04 has openings on the first segment 102-1 of the first type of light emitting layer in the first type of light emitting region A01 and the first segment 202-1 of the second type of light emitting layer in the second type of light emitting region A02.

[0080] In step S404, with reference to Figure 10 After step S403, a continuous shared top electrode layer 05 is formed on the entire substrate 100 by, for example, deposition. The shared top electrode layer 05 formed in the openings is connected to the first segment 102-1 of the first type of light emitting layer in the first type of light emitting region A01 and the first segment 202-1 of the second type of light emitting layer in the second type of light emitting region A02.

[0081] Figure 28 A structure of a multi-color light emitting pixel unit according to an embodiment of the disclosure is shown, which has a micro-gap structure in a first type of light emitting layer 102 and a second type of light emitting layer 202.

[0082] Figure 29 is a flowchart showing a method of fabricating a multi-color light emitting pixel unit 3000 as shown in Figure 3 Figures 30 to 34 is a flowchart showing a method of fabricating a multi-color light emitting pixel unit 3000 as shown in Figure 6 ​The cross-sectional view of the structure formed during the steps shown is illustrated. (Refer to...) Figure 29 Manufacturing such Figure 3 The method for the multicolor luminescent pixel unit 3000 shown includes the following steps.

[0083] In step S701, refer to Figure 30 A stacked structure comprising a first metal layer 101, a first type light-emitting layer 102, a second metal layer 201, a second type light-emitting layer 202, a third metal layer 301, and a third type light-emitting layer 302 is formed on a substrate 100 in a bottom-to-top order. In other words, the first type light-emitting layer 102, the second type light-emitting layer 202, and the third type light-emitting layer 302 are stacked on the substrate 100 from bottom to top. The first metal layer 101 is formed at the bottom of the first type light-emitting layer 102. The second metal layer 201 is formed at the bottom of the second type light-emitting layer 202. The third metal layer 301 is formed at the bottom of the third type light-emitting layer 302. The second metal layer 201 is disposed between the first type light-emitting layer 102 and the second type light-emitting layer 202. The third metal layer 301 is disposed between the second type light-emitting layer 202 and the third type light-emitting layer 302.

[0084] Figure 35 This demonstrates an implementation scheme based on this disclosure. Figure 29 A flowchart detailing step S701 is provided. (Combined with...) Figure 30 , refer to Figure 35 Step S701 further includes the following steps. It should be noted that the structures formed in steps S801 to S809 of this embodiment are not shown in the accompanying drawings. However, those skilled in the art can understand steps S801 to S809 of this embodiment by referring to steps S101 to S109 of the above-described embodiments.

[0085] In step S801, a first metal bonding layer is formed on the substrate 100, a first type of light-emitting layer 102 is formed on the first substrate, and a second metal bonding layer is formed on top of the first type of light-emitting layer 102.

[0086] More specifically, the first metal bonding layer can be fabricated by, but is not limited to, physical vapor deposition (such as evaporation, sputtering, etc.). The material of the first substrate is designed according to the first type of light-emitting layer 10. For example, the first substrate can be a gallium nitride (GaN) substrate. The first type of light-emitting layer 102 can be fabricated by, but is not limited to, epitaxial growth on the first substrate. The second metal bonding layer can be fabricated by, but is not limited to, physical vapor deposition (such as evaporation).

[0087] In step S802, the first substrate is upside down, so that the second metal bonding layer faces the first metal bonding layer, and the second metal bonding layer is bonded with the first metal bonding layer to form the first metal layer 101.

[0088] In step S803, the first substrate is removed.

[0089] Here, after the first substrate is removed, step S803 can further include: thinning the first type of light emitting layer 102. In addition, after the first substrate is removed or the first type of light emitting layer 102 is thinned, and before the third metal bonding layer is formed, referring to Figure 36 , step S803 can further include: forming a micro-gap structure 06 in the first type of light emitting layer 102. The micro-gap structure 06 is formed by, but not limited to, photolithography and etching. In photolithography, a photolithography pattern is designed according to the size of the micro-gap structure 06. According to the embodiments, the cross-sectional size of the micro-gap structure pattern is not greater than 2 nm.

[0090] In step S804, the third metal bonding layer is formed on the first type of light emitting layer 102, the second type of light emitting layer 202 is formed on the second substrate, and the fourth metal bonding layer is formed on the top of the second type of light emitting layer 202.

[0091] In step S805, the second substrate is upside down, so that the fourth metal bonding layer faces the third metal bonding layer, and then the fourth metal bonding layer is bonded with the third metal bonding layer to form the second metal layer 201.

[0092] In step S806, the second substrate is removed.

[0093] Here, after the second substrate is removed, step S106 can further include: thinning the second type of light emitting layer 202. In addition, after the second substrate is removed or the second type of light emitting layer 202 is thinned, referring to Figure 36 , step S106 further includes: forming a micro-gap structure 06 in the second type of light emitting layer 202. The micro-gap structure 06 can be formed using a process similar to the process of forming the micro-gap structure 06 described above. Therefore, the process of forming the micro-gap structure 06 will not be described again.

[0094] In step S807, the fifth metal bonding layer is formed on the second type of light emitting layer 202, the third type of light emitting layer 302 is formed on the third substrate, and the sixth metal bonding layer is formed on the top of the third type of light emitting layer 302.

[0095] In step S808, the third substrate is inverted upside down so that the sixth metal bonding layer faces the fifth metal bonding layer, and then the sixth metal bonding layer is bonded with the fifth metal bonding layer to form the third metal layer 301.

[0096] In step S809, the third substrate is removed.

[0097] Here, after the third substrate is removed, step S109 can further include: thinning the third type of light emitting layer 302. In addition, after the third substrate is removed or the third type of light emitting layer 302 is thinned, with reference to Figure 36 , step S109 further includes: forming a micro-gap structure 06 in the third type of light emitting layer 302. The micro-gap structure 06 can be formed using a process similar to the process of forming the micro-gap structure 06 described above. Therefore, the process of forming the micro-gap structure 06 will not be described again.

[0098] Figure 36 The micro-gap structure 06 in the first type of light emitting layer 102, the second type of light emitting layer 202, and the third type of light emitting layer 302 is shown.

[0099] Referring back to Figures 30 to 34 , the process after step S701 will be further described below.

[0100] In step S702, with reference to Figure 31 , the third type of light emitting layer 302 and the third metal layer 301 are patterned until a portion of the top of the second type of light emitting layer 202 is exposed, thereby forming a step structure made of the third type of light emitting layer 302 on the second type of light emitting layer 202.

[0101] More specifically, the step structure includes the third type of light emitting layer 302 and the third metal layer 301. The process of patterning the third type of light emitting layer 302 and the third metal layer 301 also includes over-etching the top of the first type of light emitting layer 102.

[0102] In step S703, with reference to Figure 32 , the second type of light emitting layer 202 and the second metal layer 201 are further patterned until a portion of the top of the first type of light emitting layer 202 is exposed, thereby forming a step structure made of the second type of light emitting layer 202 on the first type of light emitting layer 102.

[0103] More specifically, the step structure is made of the second type of light emitting layer 202 and the second metal layer 201. The patterning process can be performed by photolithography and plasma etching. The process of patterning the second type of light emitting layer 202 and the second metal layer 201 also includes over-etching the top of the first type of light emitting layer 102. The parameters of the patterning process can be set according to actual needs, which will not be limited here.

[0104] In step S704, referring to Figure 33 , according to the preset first type of light emitting area A01, the preset second type of light emitting area A02 and the preset third type of light emitting area A03, the third type of light emitting layer 302, the third metal layer 301, the second type of light emitting layer 202, the second metal layer 201, the first type of light emitting layer 102 and the first metal layer 101 are etched, so as to divide the first type of light emitting layer 102 in the first type of light emitting area A01 from the first type of light emitting layer in the second type of light emitting area A02 and the third type of light emitting area A03, divide the first metal layer 101 in the first type of light emitting area A01 from the first metal layer in the second type of light emitting area A02 and the third type of light emitting area A03, divide the second type of light emitting layer 202 in the second type of light emitting area A02 from the second type of light emitting layer in the third type of light emitting area A03, and divide the second metal layer 201 in the second type of light emitting area A02 from the second metal layer in the third type of light emitting area A03. As a result of step S704, the first type of LED 01 including the first section 101-1 of the first metal layer and the first section 102-1 of the first type of light emitting layer, the second type of LED 02 including the second section 101-2 of the first metal layer, the second section 102-2 of the first type of light emitting layer, the first section 201-1 of the second metal layer and the first section 202-1 of the second type of light emitting layer, and the third type of LED 03 including the third section 101-3 of the first metal layer, the third section 102-3 of the first type of light emitting layer, the second section 201-2 of the second metal layer, the second section 202-2 of the second type of light emitting layer, the first section 301-1 of the third metal layer and the first section 302-1 of the third type of light emitting layer are formed.

[0105] Here, the etching process is performed by photolithography and etching process, and the parameters can be set according to actual needs.

[0106] According to embodiments, as a result of step S704, the plurality of multicolor light emitting pixel units are divided from each other according to the preset pixel unit array. Thus, the light emitting transistors in the pixel units and / or the pixel unit array can be prepared by one division step, which simplifies the process and reduces the production cost, especially facilitates mass production.

[0107] In step S705, referring to Figure 34 On top of the first section 102-1 of the first type of light emitting layer, the first section 202-1 of the second type of light emitting layer and the first section 302-1 in the third type of light emitting layer, a shared top electrode layer 05 is formed, which serves as the lead-out electrode of the first section 201-1 of the second metal layer and the lead-out electrode of the first section 301-1 of the third metal layer.

[0108] Figure 37 is a flow chart showing details of step S705 in Figure 29 according to embodiments of the present disclosure. Figures 38 to 40 is a cross-sectional view showing the structure formed in the steps shown in Figure 37 Referring to Figure 37 , step S705 further comprises the following steps.

[0109] In step S501, referring to Figure 38 , a portion of the first section 302-1 of the third type of light emitting layer and a portion of the first section 202-1 of the second type of light emitting layer are removed, thereby exposing a portion of the first section 201-1 of the second metal layer and a portion of the first section 301-1 of the third metal layer.

[0110] In step S502, referring to Figure 39 , the first electrical connector 203 is formed on the sidewall and top of the first section 201-1 of the second metal layer in the second type of light emitting region A02, on the sidewall of the second section 102-2 of the first type of light emitting layer and on the sidewall of the second section 101-2 of the first metal layer, and the second electrical connector 303 is formed on the top and sidewall of the first section 301-1 of the third metal layer in the third type of light emitting region A03, on the sidewall of the second section 202-2 of the second type of light emitting layer, on the sidewall of the second section 201-2 of the second metal layer, on the sidewall of the third section 102-3 of the first type of light emitting layer and on the sidewall of the third section 101-3 of the first metal layer.

[0111] More specifically, referring to Figure 39The process of manufacturing the first electrical connectors 203 and the second electrical connectors 303 further comprises the following steps. It should be noted that the following steps S5021 to S5023 are not shown in the figures, but a person skilled in the art can understand steps S5021 to S5023 with reference to steps S4021 to S4023 of the above-described embodiment.

[0112] In step S5021, a mask is formed on the substrate 100 to mask the areas without the first electrical connectors 203 and the second electrical connectors 303, thereby exposing the top and sidewalls of the first segment 201-1 of the second metal layer in the second type of light emitting area A02, the sidewalls of the second segment 102-2 of the first type of light emitting layer and the second segment 101-2 of the first metal layer, and exposing the top and sidewalls of the first segment 301-1 of the third metal layer in the third type of light emitting area A03, the sidewalls of the second segment 202-2 of the second type of light emitting layer, the sidewalls of the second segment 201-2 of the second metal layer, the sidewalls of the third segment 102-3 of the first type of light emitting layer and the third segment 101-3 of the first metal layer.

[0113] In step S5022, after step S5021 is completed, a conductive material is deposited on the substrate 100.

[0114] In step S5023, with reference to Figure 39 , the mask and the conductive material on the mask are removed, thereby forming the first electrical connectors 203 on the top and sidewalls of the first segment 201-1 of the second metal layer in the second type of light emitting area A02, on the sidewalls of the second segment 102-2 of the first type of light emitting layer and the second segment 101-2 of the first metal layer, and forming the second electrical connectors 303 on the top and sidewalls of the first segment 301-1 of the third metal layer in the third type of light emitting area A03, on the sidewalls of the second segment 202-2 of the second type of light emitting layer, on the sidewalls of the second segment 201-2 of the second metal layer, on the sidewalls of the third segment 102-3 of the first type of light emitting layer and on the sidewalls of the third segment 101-3 of the first metal layer.

[0115] The process of manufacturing the shared top electrode layer 05 will be further described in the following.

[0116] In step S503, with reference to Figure 40 , the isolation layer 04 is formed to cover the first type of light emitting area A01, the second type of light emitting area A02, the third type of light emitting area A03 and the surface of the exposed substrate 100. The isolation layer 04 has openings on the first segment 102-1 of the first type of light emitting layer, on the first segment 202-1 of the second type of light emitting layer and on the first segment 302-1 of the third type of light emitting layer.

[0117] In step S504, referring again to Figure 34 After step S503, a continuous shared top electrode layer 05 is formed on the entire substrate 100. The shared top electrode layer 05 deposited in the openings is connected to the first segments 102-1 of the first type of light emitting layer, to the first segments 202-1 of the second type of light emitting layer, and to the first segments of the third type of light emitting layer 302.

[0118] As mentioned above, in the method of manufacturing multi-color light emitting pixel units according to the embodiments of the disclosure, since the film deposition process of each type of LED can be performed simultaneously, the LEDs can be prepared simultaneously without being prepared separately, thereby simplifying the process of manufacturing multi-color light emitting pixel units and micro-LED display panels, and facilitating mass production. Due to the manufacturing method according to the embodiments of the disclosure, different types of LEDs are arranged side by side on the same substrate, and the distance between them is short. Therefore, the size of the LEDs and the display panel made of the LEDs can be reduced. For example, the size of each LED can be 40 µm × 40 µm. In addition, the tops of different types of LEDs are not at the same level. That is, the heights of different types of LEDs are different, so that different types of light emitting layers are exposed on the tops of different types of LEDs, thus ensuring the light emitting area and improving the light emitting efficiency of each LED, and improving the integration of various LEDs. The micro-LED display panel formed by the pixel units of the embodiments of the disclosure has clear picture display and high resolution. In addition, since the electrical connectors connect each metal layer in the Mth type of LED, the Mth type of light emitting layer (which is a top light emitting layer) in the Mth type of LED can emit light, while other light emitting layers in the Mth type of LED are short-circuited due to the metal layers disposed on both sides of each light emitting layer being electrically connected to each other. For example, in the Mth type of LED, the first type of light emitting layer is short-circuited due to the first type of metal layer and the second type of metal layer disposed on both sides of the first type of light emitting layer being electrically connected to each other; the second type of light emitting layer is short-circuited due to the second type of metal layer and the third type of metal layer disposed on both sides of the second type of light emitting layer being electrically connected to each other; and so on. Therefore, various types of LEDs emit light individually without affecting each other. In addition, the micro-gaps in the light emitting layers can release the stress inside the light emitting layers and avoid warping without affecting the light emitting efficiency of the light emitting layers, thus improving the product yield.

[0119] While the application has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit and scope of the application as defined by the appended claims.

Claims

1. A light emitting pixel unit, characterized by, comprise: a plurality of light emitting transistors; a top electrode layer above the plurality of light emitting transistors; and an isolation layer formed between the top electrode layer and the plurality of light emitting transistors, wherein the isolation layer comprises a plurality of openings respectively on the plurality of light emitting transistors, and the top electrode layer is electrically connected with the plurality of light emitting transistors via the plurality of openings in the isolation layer. Further comprising a substrate on which the plurality of light emitting transistors are formed.

2. The light-emitting pixel unit according to claim 1, characterized in that The substrate is an integrated circuit substrate comprising at least a driving circuit which respectively controls each of the light emitting transistors.

3. The light-emitting pixel unit according to claim 2, characterized in that The substrate comprises an interconnection layer electrically connected with the plurality of light emitting transistors.

4. The light-emitting pixel unit according to claim 3, characterized in that Further comprising an isolation structure arranged outside each of the light emitting transistors and between adjacent transistors of the plurality of light emitting transistors.

5. The light-emitting pixel unit of claim 1, wherein, The isolation structure is an isolation trench.

6. The light-emitting pixel unit according to claim 5, characterized in that The isolation layer is above the plurality of light emitting transistors, wherein the plurality of openings expose the plurality of light emitting transistors.

7. The light-emitting pixel unit of claim 1, wherein, The top electrode layer is shared by the plurality of light emitting transistors.

8. The light-emitting pixel unit of claim 1, wherein, The top electrode layer is a transparent conductive layer.

9. The light-emitting pixel unit of claim 1, wherein, Each of the plurality of light emitting transistors comprises a bottom conductive layer formed at a bottom thereof.

10. The light-emitting pixel unit of claim 1, wherein, The bottom conductive layer is a metal layer.

11. The light-emitting pixel unit according to claim 10, characterized in that A bottom width of the bottom conductive layer is greater than an upper width of the bottom conductive layer.

12. The light-emitting pixel unit of claim 10, wherein, Each of the plurality of light emitting transistors comprises a bottom conductive layer and a light emitting layer on the bottom conductive layer.

13. The light-emitting pixel unit of claim 1, wherein, The light emitting layer comprises a single layer or multiple layers.

14. The light-emitting pixel unit of claim 13, wherein, Each of the plurality of openings formed in the isolation layer exposes a portion of the light emitting layer of one of the light emitting transistors.

15. The light-emitting pixel unit of claim 13, wherein, Each of the plurality of light emitting transistors is one of a light emitting diode or a Schottky light emitting transistor.

16. The light-emitting pixel unit of claim 1, wherein, The plurality of light emitting transistors comprises a red light emitting transistor.

17. The light-emitting pixel unit of claim 1, wherein, comprise the light emitting pixel unit according to claim 1.

18. A micro display chip, comprising: comprise the light emitting pixel unit according to claim 1.

19. A microdisplay panel, characterized by, ​

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