Method for manufacturing multi-color luminous pixel unit

Abstract

A method for manufacturing a multi-color light-emitting pixel unit, comprising: forming a stacked structure on a substrate, the stacked structure comprising, in order from bottom to top, a first metal layer, a first type of light-emitting layer, a second metal layer, and a second type of light-emitting layer; patterning the second type of light-emitting layer and the second metal layer until a portion of the first type of light-emitting layer is exposed; and selectively etching the stacked structure to form a first light-emitting transistor and a second light-emitting transistor, the first light-emitting transistor comprising the first metal layer and the first type of light-emitting layer, and the second light-emitting transistor comprising the first metal layer, the first type of light-emitting layer, the second metal layer, and the second type of light-emitting layer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Patent Application No. 16 / 567,028, filed on September 11, 2019. The contents of the foregoing application are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure generally relates to the field of semiconductor manufacturing technology, and more particularly to a method for manufacturing a multi-color light-emitting pixel unit. Background Art

[0004] With the need for miniaturization and portability of electronic devices, it is increasingly important to integrate multiple different types of light-emitting transistors and multi-color light-emitting pixel units for light-emitting devices. The conventional process of manufacturing a multi-color display chip includes: first forming a first type of light-emitting area, and then forming another type of light-emitting area. Due to the complexity of the alignment process and the transfer process, the conventional process of manufacturing different types of light-emitting areas becomes increasingly difficult, resulting in problems such as reduced alignment accuracy, reduced yield, and increased cost.

[0005] In addition, the conventional process of manufacturing various light-emitting areas generally includes: bonding a substrate with an epitaxial layer to a base plate, and then peeling off the substrate, which generates stress in the epitaxial layer, which may cause warping and deformation of the epitaxial layer. In addition, the current light-emitting display chips integrating different types of light-emitting areas also have problems such as high power consumption and heat dissipation. Summary of the invention

[0006] According to one aspect of the present disclosure, a method for manufacturing a multi-color light-emitting pixel unit is provided. The method comprises: forming a stacked structure on a substrate, the stacked structure comprising a first metal layer, a first type of light-emitting layer, a second metal layer, and a second type of light-emitting layer in order from bottom to top; patterning the second type of light-emitting layer and the second metal layer until a portion of the first type of light-emitting layer is exposed; and selectively etching the stacked structure to form a first light-emitting transistor and a second light-emitting transistor, the first light-emitting transistor comprising the first metal layer and the first type of light-emitting layer, and the second light-emitting transistor comprising the first metal layer, the first type of light-emitting layer, the second metal layer, and the second type of light-emitting layer. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

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

[0013] 7 to 10 are cross-sectional views showing structures formed in steps of the method in FIG. 6 according to an embodiment of the present disclosure.

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

[0015] 12 to 21 are cross-sectional views showing structures formed in the steps of FIG. 11 according to an embodiment of the present disclosure.

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

[0017] 23 to 25 are cross-sectional views showing the structure formed in the steps of FIG. 22 according to an embodiment of the present disclosure.

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

[0019] FIG. 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] FIG. 29 is a flow chart showing a method of manufacturing the multi-color light-emitting pixel unit shown in FIG. 3 according to an embodiment of the present disclosure.

[0021] 30 to 34 are cross-sectional views showing structures formed in steps of the method in FIG. 29 according to an embodiment of the present disclosure.

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

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

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

[0025] 38 to 40 are cross-sectional views showing the structure formed in the steps of FIG. 37 according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0026] Reference will now be made in detail to the presented preferred embodiments to provide a further understanding of the present disclosure.The specific embodiments and drawings discussed merely illustrate specific ways to make and use the present disclosure and do not limit the scope of the present disclosure or the appended claims.

[0027] Hereinafter, the present disclosure is further described through embodiments of the present disclosure in conjunction with Figures 1 to 40. It should be noted that all drawings are in a very simplified form and the imprecise scale is only used to help conveniently and clearly explain the embodiments of the present disclosure.

[0028] The multicolor luminous pixel unit disclosed in this article includes at least one type of light-emitting transistor, or several types of light-emitting transistors. 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 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 a multilayer. The intermediate layer can be arranged between two light-emitting layers of the multiple light-emitting layers in the same light-emitting diode. Assume that the multicolor luminous pixel unit includes first to M-th types of light-emitting transistors, where M is an integer and not less than two. Each of the first to M-th types of light-emitting transistors includes at least the same type of light-emitting layer. For example, each of the first to M-th types of light-emitting transistors includes a first type of light-emitting layer. Any of the second to M-th 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-mentioned pixel units arranged in a matrix.

[0029] In some embodiments, the light emitting transistor may be at least one of a light emitting diode (LED), a Schottky light emitting transistor, and the like. 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. In the following, LED is used as an example of a light emitting transistor, but this does not limit the scope of the present disclosure. Those skilled in the art can change the LED into another light emitting transistor according to conventional technical means.

[0030] FIG. 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 FIG. 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 at the same level 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 shown in FIG. 1 , the top of the first type of LED 01 is lower than the top of the second type of LED 02. According to the embodiment, 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. In addition, 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. Furthermore, depending on the different colors that may be required, the light emitting area of ​​the green LED may be smaller than the light emitting area of ​​the red LED.

[0031] In addition, an isolation structure 07 is arranged between the first type of LED and the second type of LED. 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 multicolor 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 LED 01 includes at least a first segment 101-1 of the first metal layer and a first segment 102-1 of the first type of light-emitting layer in order from bottom to top. The first segment 101-1 of the first metal layer constitutes the 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 the second metal layer, and a first segment 202-2 of the second type of light-emitting layer, and a first electrical connector 203 in order from bottom to top. 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 LED 01 from the second segment 101-2 of the first metal layer in the second type 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 LED 01 from the second segment 102-2 of the first type of light emitting layer in the second type LED 02. In addition, in order 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 LED 02 are electrically connected to each other through the first electrical connector 203. According to one embodiment, the first electrical connector 203 can be attached to and contact a portion or all of the sidewall surface of the second type LED 02. Alternatively, the first electrical connector 203 may be attached to and contact only the surface 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 may be formed as a conductive side arm that is attached to and contacts 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 may have other shapes, such as a curve. In the embodiment illustrated in FIG. 1 , the first electrical connector 203 is attached to the sidewall of the second type of LED 02 so that the first electrical connector 203 follows the surface topography of the sidewall of the second type of LED 02.

[0032] 1 , a top insulating layer 04 and a top transparent conductive layer 05 are arranged on a first segment 102-1 of a first type of light emitting layer in a first type of LED 01 and a first segment 202-1 of a second type of light emitting layer in a second type of LED 02. The top insulating 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, and the exposed substrate 100. The top insulating layer 04 has an opening that exposes a portion of the top surface of the first segment 102-1 of the first type of light emitting layer and the first segment 202-1 of the second type of 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, and thereby contacts the exposed top surface of the first segment 102-1 of the first type of light emitting layer and the first segment 202-1 of the second type of light emitting layer via the opening.

[0033] The substrate 100 is an integrated circuit (IC) substrate. The IC substrate includes an interconnection layer, which is electrically connected to the first segment 101-1 of the first metal layer in the first type LED 01 and the second segment 1012 of the first metal layer in the second type LED 02. Since the first electrical connector 203 is connected to the second segment 101-2 of the first metal layer in the second type LED 02, the first electrical connector 203 is connected to the interconnection layer in the substrate 100. In addition, referring to FIG. 1, the bottom of the first electrical connector 203 extends to the substrate 100 to connect to the interconnection layer. Here, the IC substrate includes at least a drive circuit. The drive circuit controls each LED separately.

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

[0035] In the multi-color light-emitting pixel unit 2000, the structures of the first type LED 01 and the second type LED 02 are the same as those of the first type LED 01 and the second type LED 02 in the multi-color light-emitting pixel unit 2000, and thus their detailed descriptions are not repeated. The third type LED 03 in the multi-color light-emitting pixel unit 2000 includes, in order from bottom to top, at least the third segment 101-3 of the first metal layer, the third segment 102-3 of the first type light-emitting layer, the first segment 301-1 of the third metal layer, and the first segment 302-1 of the third type light-emitting layer, 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, which covers the first type LED 01, the second type LED 02, and the third type LED 03 and has an opening, wherein the opening exposes a portion of the first segment of the first type light-emitting layer 102-1, a portion of the first segment 202-1 of the second type light-emitting layer, and a portion of the first segment 302-1 of the third type light-emitting layer in the first type LED 01. The top electrode layer 05 is formed on the top of the top isolation layer 04, and contacts 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 first segment 302-1 of the third type light-emitting layer via the opening of the top isolation layer 04.

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

[0037] FIG. 4 is a top view of a multicolor light-emitting pixel unit 4000 according to an embodiment of the present disclosure. The multicolor light-emitting pixel unit 4000 may be the multicolor light-emitting pixel unit 2000 shown in FIG. 2 or the multicolor light-emitting pixel unit 3000 shown in FIG. 3. FIG. 4 shows the arrangement of three types of LEDs 01, 02, and 03 in a 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 larger 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 larger than the size of the light-emitting area of ​​the green LED. As shown in FIG. 4 , the space between the red LED and the blue LED is larger than the space between the blue LED and the green LED; the space between the red LED and the green LED is larger than the space between the blue LED and the green LED, thereby achieving a better lighting effect.

[0038] Referring back to FIG. 3 , an isolation structure 07 is arranged between two of the first type LED 01, the second type LED 02, and the third type LED 03. The isolation structure is an isolation trench. The first type LED 01, the second type LED 02, and the third type LED 03 are formed by 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. The first type LED 01 and the second type LED 02 in FIG. 3 are the same as the first type LED 01 and the second type LED 02 in FIG. 2 . Specifically, as illustrated in FIG. 3 , the first type LED 01 includes at least a first segment 101-1 of the first metal layer and a first segment 102-1 of the first type light emitting layer in order from bottom to top. The second type LED 02 includes, in order from bottom to top, at least 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 first segment 202-1 of the second type of light emitting layer, and a first electrical connector 203. The third type LED 03 includes, in order from bottom to top, 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 second segment 201-2 of the second metal layer, the second segment 202-2 of the second 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, and a second electrical connector 303. As shown in FIG. 3 , 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 to the substrate 100. The first electrical connector 203 in the second type 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 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 LED 01 from the second segment 101-2 of the first metal layer in the second type LED 02 and the third segment 101-3 of the first metal layer in the third type LED 03, isolates the first segment 102-1 of the first type of light-emitting layer in the first type LED 01 from the second segment 102-2 of the first type of light-emitting layer in the second type LED 02 and the third segment 102-3 of the first type of light-emitting layer in the third type LED 03, isolates the first segment 201-1 of the second metal layer in the second type LED 02 from the second segment 201-2 of the second metal layer in the third type LED 03, and isolates the first segment 202-1 of the second type of light-emitting layer in the second type LED 02 from the second segment 202-2 of the second type of light-emitting layer in the third type 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, and 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, in the same manner as FIG. 1, 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.In addition, the bottom of the first electrical connector 203 and the bottom of the second electrical connector 303 are respectively and directly in contact with 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 conductive metal. In the embodiment, the second electrical connector 303 is attached to and contacts the side wall surface of the third type 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. Therefore, 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, so 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. Therefore, 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, so 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. Therefore, 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 FIG. 3 , a top insulating layer 04 and a top transparent conductive layer 05 are arranged on the first type LED 01, the second type LED 02, and the third type LED 03. 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, the first segment 302-1 of the third type light emitting layer, and the exposed substrate 100. An opening is arranged in the top insulating layer 04 to expose a portion of the top surface of 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 first segment 302-1 of the third 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 surface of the first segment 102-1 of the first type light emitting layer, the exposed top surface of the first segment 202-1 of the second type light emitting layer, and the exposed top surface of the first segment 302-1 of the third type light emitting layer.

[0041] The detailed description of the substrate 100 in the multicolor light-emitting pixel unit 3000 having at least three types of LEDs corresponds to the description of FIG. 1 and will not be repeated here. It should be noted that the interconnection layer in the IC substrate 100 is electrically connected to 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 separately.

[0042] In the multi-color light-emitting pixel units 1000 to 4000 in FIGS. 1 to 4 , one or more of the light-emitting layers 102, 202, and 302 may have a micro-gap structure. For example, in the multi-color light-emitting pixel unit 1000 shown in FIG. 1 , the first type of light-emitting layer 102 may have a micro-gap structure, or the second type of light-emitting layer 202 may have a micro-gap structure, or both the first type of light-emitting layer 102 and the second type of light-emitting layer 202 may have a micro-gap structure. As another example, in the multi-color light-emitting pixel unit 3000 shown in FIG. 3, the first type of light-emitting layer 102 may have a micro-gap structure, or the second type of light-emitting layer 202 may have a micro-gap structure, or the third type of light-emitting layer 302 may have a micro-gap structure, or the first type of light-emitting layer 102 and the second type of light-emitting layer 202 may both have a micro-gap structure, or the second type of light-emitting layer 202 and the third type of light-emitting layer 302 may both have a micro-gap structure, or the first type of light-emitting layer 102 and the third type of light-emitting layer 302 may both have a micro-gap structure, or 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 may all have a micro-gap structure. Here, each of the micro-gap structures in the multi-color light-emitting pixel units 1000 to 3000 shown in FIGS. 1 to 3 may be, but is not limited to, an air gap. The air gap is sealed. Preferably, the cross-sectional size of the air gap is not greater than 2 nm, thereby releasing the stress in the light-emitting layer and avoiding bending of the light-emitting layer without affecting the light-emitting efficiency of the light-emitting layer. Here, the cross-sectional size of the air gap may be a diameter of the cross section of the air gap, or a length or a width of the cross section of the air gap.

[0043] FIG5 is a cross-sectional view showing a multi-color light-emitting pixel unit 5000 according to an embodiment of the present disclosure. As shown in FIG5, 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 may have a plurality of micro-gap structures 06. Each of the micro-gap structures 06 extends in 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 the embodiment, the micro-gap structure 06 is arranged in at least one light-emitting layer, preferably in the top light-emitting layer.

[0044] Still referring to FIG. 5 , the micro-gap structures 06 are staggered in the plurality of light-emitting layers. That is, the micro-gap structures 06 in the first type of light-emitting layer 102 are not vertically aligned with the micro-gap structures 06 in the second type of light-emitting layer 202, and the micro-gap structures 06 in the second type of light-emitting layer 202 are not vertically aligned with the micro-gap 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 micro-gap structures in the first type of light-emitting layer 102 are isolated and sealed between the second metal layer 201 at the top of the first type of light-emitting layer 102 and the first metal layer 101 at the bottom thereof. In the third type of LED 03, the micro-gap structures 06 in the second type of light-emitting layer 202 are isolated and sealed between the third metal layer 301 at the top of the second light-emitting layer 202 and the second metal layer 201 at the bottom thereof, and the micro-gap structures 06 in the third type of light-emitting layer 302 are isolated and sealed between the top isolation layer 04 at the top of the third type of light-emitting layer 302 and the third metal layer 301 at the bottom thereof.

[0045] In a similar manner, in another embodiment of the present disclosure, in a multicolor light-emitting pixel unit including first to M-th type LEDs, the M-th type LED has M light-emitting layers, and a metal layer is arranged at 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 to M-th type LEDs, a top conductive layer (as an upper conductive layer) is arranged on top of the top light-emitting layer, so that a microgap structure in the top light-emitting layer can be isolated and sealed between the top conductive layer and the metal layer at the bottom of the top light-emitting layer. The microgap structure in each light-emitting layer is isolated and sealed between the metal layers at the top and bottom of the relative light-emitting layer, respectively.

[0046] In addition, similar to the multicolor light-emitting pixel units 1000 to 4000 in Figures 1 to 4, the multicolor light-emitting pixel unit according to another embodiment of the present disclosure includes a plurality of LEDs (including LEDs of the first type to the Mth type). The Mth type of LED includes at least all the light-emitting layers and metal layers constructed in the (M-1)th type of LED and the Mth light-emitting layer and the Mth metal layer. On this basis, the Mth type of LED has an (M-1)th electrical connector, which is 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 Figure 1. The first to (M-1)th electrical connectors connect the first to the Mth metal layers, and the first to (M-1)th electrical connectors can directly contact the substrate and the first metal layer. Here, there are differences from the first type of LED to the Mth type of LED. In addition, each 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. Here, LEDs of different colors are conventional LEDs, which are known to those skilled in the art and will not be described here. 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 the Mth type of LED. The top isolation layer of each type of LED has its opening, 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 electrically contacted with the top light-emitting layer of each type of LED. Referring to Figures 4 and 5, in a pixel unit with M types of LEDs, the sizes of the light-emitting areas of the first to the Mth types of LEDs are 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. Optionally, the first type of LED is a red LED, and its light-emitting area is larger than 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 multi-color micro display panel according to an embodiment of the present disclosure is also provided. The micro display panel comprises a plurality of multi-color pixel units arranged in a matrix. The multi-color pixel units herein may be the above-mentioned LED pixel units.

[0048] The method for manufacturing a multi-color light-emitting pixel unit will be further described below in conjunction with the accompanying drawings.

[0049] FIG6 is a flow chart showing a method for manufacturing the multi-color light-emitting pixel unit shown in FIG1 according to an embodiment of the present disclosure. FIG7 to FIG10 are cross-sectional views showing structures formed in the steps shown in FIG6 according to an embodiment of the present disclosure. Referring to FIG6, the method for manufacturing the multi-color light-emitting pixel unit shown in FIG1 includes the following steps.

[0050] In step S601, referring to FIG7, a stacked 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 from bottom to top on a substrate 100. In other words, the first type of light emitting layer 102 and the second type of light emitting layer 202 are stacked from bottom to top on the substrate 100. 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 type of light emitting layer 202.

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

[0052] Figure 11 is a flow chart showing details of step S601 in Figure 6 according to an embodiment of the present disclosure. Figures 12 to 21 are cross-sectional views showing structures formed in the steps shown in Figure 11 according to an embodiment of the present disclosure. Referring to Figure 11, step S601 further includes the following specific steps.

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

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

[0055] In step S102 , referring to FIG. 13 in combination with FIG. 12 , the first substrate B1 is turned 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 to the first metal bonding layer M01 to form a first metal layer 101 .

[0056] In step S103 , referring to FIG. 14 in combination with FIG. 13 , the first substrate B1 is removed.

[0057] Here, after removing the first substrate B1 , referring to FIG. 15 , step S103 may further include: thinning the first type light emitting layer 102 .

[0058] In addition, according to the embodiment, after removing the first substrate B1 or thinning the first type of light-emitting layer 102, and before forming the third metal bonding layer, referring to FIG. 16, step S103 may further include: forming a microgap structure 06 in the first type of light-emitting layer 102. The microgap structure 06 is formed by, but not limited to, photolithography and etching. In the photolithography, the photolithography pattern is designed according to the size of the microgap structure 06. According to the embodiment, the cross-sectional size of the microgap structure pattern is not greater than 2nm. Here, the cross-sectional size of the air gap may 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 FIG. 17 , a third metal bonding layer M03 is formed on the first type light emitting layer 102 , a second type light emitting layer 202 is formed on the second substrate B2 , and a fourth metal bonding layer M04 is formed on top of the second type light emitting layer 202 .

[0060] In step S105, in combination with FIG. 17 and referring to FIG. 18 , the second substrate B2 is turned 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 to the third metal bonding layer M03 to form a second metal layer 201.

[0061] In step S106 , referring to FIG. 19 in combination with FIG. 18 , the second substrate B2 is removed.

[0062] Here, after removing the second substrate B2, referring to FIG. 20, in step S106, the second type light emitting layer 202 is thinned.

[0063] According to the embodiment, after removing the second substrate B2 or thinning the second type of light emitting layer 202, referring to FIG. 21, in step S106, a micro-gap structure 06 is formed in the second type of light emitting layer 202. The micro-gap structure 06 is formed using 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 repeatedly described.

[0064] Referring back to FIGS. 6 to 10 , the process after step S601 according to an embodiment of the present disclosure will be further described below.

[0065] In step S602 , referring to FIG. 8 , the second type light emitting layer 202 and the second metal layer 201 are patterned until a portion of the top of the first type light emitting layer 102 is exposed, thereby forming a stepped structure made of the second type light emitting layer 202 on the first type 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 and will not be limited here.

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

[0068] Here, the process of etching the second type light emitting layer 202, the second metal layer 201, the first type 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 the embodiment, as a result of step S603, a plurality of multi-color light-emitting pixel units are divided into each other according to a preset pixel unit array. In this way, the light-emitting transistors in the pixel unit and / or the pixel unit array can be prepared by a division step, which simplifies the process and reduces the production cost, and especially promotes mass production.

[0070] In step S604, referring to FIG. 10, a shared top electrode layer 05 serving as an extraction electrode of the second metal layer 201 is formed on top 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 in the second type light emitting area A02.

[0071] Fig. 22 is a flow chart showing details of step S604 in Fig. 6 according to an embodiment of the present disclosure. Fig. 23 to Fig. 25 are cross-sectional views showing structures formed in the steps shown in Fig. 22 according to an embodiment of the present disclosure. Referring to Fig. 22, the specific process of step S604 includes the following steps.

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

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

[0074] 26 to 27 are cross-sectional views showing a structure formed in the steps of manufacturing the first electrical connector 203 according to an embodiment of the present disclosure. In step S402, the first electrical connector 203 is formed through the following specific steps.

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

[0076] In step S4022 , referring to FIG. 27 , after step S4021 is completed, a conductive material 203 ′ is deposited on the substrate 100 .

[0077] In step S4023, referring to Figure 10 again, mask Y and the conductive material 203' on mask Y are removed, thereby forming a first electrical connector 203 on the top and side wall of the first segment 201-1 of the second metal layer of the second type of light-emitting area A02, on the side wall of the second segment 102-2 of the first type of light-emitting layer, and on the side wall of the second segment 101-2 of the first metal layer.

[0078] The process of manufacturing the shared top electrode layer 05 will be further described below.

[0079] In step S403, referring to Fig. 25, an isolation layer 04 is formed to cover the first type light emitting area A01, the second type light emitting area A02 and the exposed surface of the substrate 100. The isolation layer 04 has an opening on the first segment 102-1 of the first type light emitting layer of the first type light emitting area A01 and the first segment 202-1 of the second type light emitting layer of the second type light emitting area A02.

[0080] In step S404, referring again to Fig. 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 opening is connected to the first segment 102-1 of the first type of light emitting layer in the first type of light emitting area A01 and the first segment 202-1 of the second type of light emitting layer in the second type of light emitting area A02.

[0081] FIG. 28 shows the structure of a multi-color light-emitting pixel unit according to an embodiment of the present disclosure, wherein the multi-color light-emitting pixel unit has a micro-gap structure in the first type light-emitting layer 102 and the second type light-emitting layer 202 .

[0082] FIG29 is a flow chart showing a method of manufacturing the multi-color light-emitting pixel unit 3000 shown in FIG3 according to an embodiment of the present disclosure. FIG30 to FIG34 are cross-sectional views showing structures formed in the steps shown in FIG6 according to an embodiment of the present disclosure. Referring to FIG29, the method of manufacturing the multi-color light-emitting pixel unit 3000 shown in FIG3 includes the following steps.

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

[0084] FIG. 35 is a flow chart showing the details of step S701 in FIG. 29 according to an embodiment of the present disclosure. Referring to FIG. 35 in conjunction with FIG. 30 , step S701 further includes the following steps. It should be noted that the structures formed in steps S801 to S809 of the present embodiment are not shown in the accompanying drawings. However, those skilled in the art can understand steps S801 to S809 of the present embodiment with reference to steps S101 to S109 of the above-described embodiment.

[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 base, 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 prepared by, but 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 made by, but not limited to, epitaxial growth on the first substrate. The second metal bonding layer can be prepared by, but not limited to, physical vapor deposition (such as evaporation).

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

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

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

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

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

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

[0093] Here, after removing the second substrate, step S106 may further include: thinning the second type of light emitting layer 202. In addition, after removing the second substrate or thinning the second type of light emitting layer 202, referring to FIG. 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 repeatedly described.

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

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

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

[0097] Here, after removing the third substrate, step S109 may further include: thinning the third type of light emitting layer 302. In addition, after removing the third substrate or thinning the third type of light emitting layer 302, referring to FIG. 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 repeatedly described.

[0098] FIG. 36 shows the micro-gap structure 06 in the first type light-emitting layer 102 , the second type light-emitting layer 202 , and the third type light-emitting layer 302 .

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

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

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

[0102] In step S703 , referring to FIG. 32 , the second type light emitting layer 202 and the second metal layer 201 are further patterned until a portion of the top of the first type light emitting layer 202 is exposed, thereby forming a stepped structure made of the second type light emitting layer 202 on the first type 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: 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 and 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, there are formed: a first type of LED 01 including a first segment 101-1 of a first metal layer and a first segment 102-1 of a first type of light-emitting layer; a second type of LED 02 including 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 the second metal layer and a first segment 202-1 of the second type of light-emitting layer; and a third type of LED 03 including a third segment 101-3 of the first metal layer, a third segment 102-3 of the first type of light-emitting layer, a second segment 201-2 of the second metal layer, a second segment 202-2 of the second type of light-emitting layer, a first segment 301-1 of the third metal layer and a first segment 302-1 of the third type of light-emitting layer.

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

[0106] According to the embodiment, as a result of step S704, a plurality of multi-color light-emitting pixel units are divided into each other according to a preset pixel unit array. Therefore, the light-emitting transistors in the pixel unit and / or the pixel unit array can be prepared by a division step, which simplifies the process and reduces the production cost, and especially promotes mass production.

[0107] In step S705, referring to Figure 34, a shared top electrode layer 05 serving as an extraction electrode for the first segment 201-1 of the second metal layer and an extraction electrode for the first segment 301-1 of the third metal layer is formed on the top 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.

[0108] Fig. 37 is a flow chart showing details of step S705 in Fig. 29 according to an embodiment of the present disclosure. Fig. 38 to Fig. 40 are cross-sectional views showing structures formed in the steps shown in Fig. 37. Referring to Fig. 37, step S705 further includes the following steps.

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

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

[0111] More specifically, referring to Figure 39, the process of manufacturing the first electrical connector 203 and the second electrical connector 303 further includes the following steps. It should be noted that the following steps S5021 to S5023 are not shown in the drawings, but those skilled in the art can understand the steps S5021 to S5023 by referring to the steps S4021 to S4023 of the above embodiment.

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

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

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

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

[0117] In step S504, referring again to FIG34, 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 opening is connected to the first segment 102-1 of the first type of light-emitting layer, to the first segment 202-1 of the second type of light-emitting layer, and to the first segment 302 of the third type of light-emitting layer.

[0118] As mentioned above, in the method for manufacturing a multi-color luminous pixel unit according to the embodiment of the present 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 a multi-color luminous pixel unit and a micro-LED display panel, and promoting large-scale production. Due to the manufacturing method according to the embodiment of the present 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 LED and the display panel made of the LED can be reduced. For example, the size of each LED can be 40μm×40μm. In addition, the tops of different types of LEDs are not on the same horizontal plane. 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, thereby 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 unit of the embodiment of the present disclosure has a clear picture display and high resolution. In addition, since the electrical connector connects each metal layer in the Mth type of LED, the Mth type of light-emitting layer (which is the top light-emitting layer) in the Mth type of LED can emit light, while the other light-emitting layers in the Mth type of LED are short-circuited due to the electrical connection of the metal layers arranged on both sides of each other light-emitting layer. For example, in the Mth type of LED, the first type of light-emitting layer is short-circuited due to the electrical connection of the first type of metal layer and the second type of metal layer arranged on both sides of the first type of light-emitting layer; the second type of light-emitting layer is short-circuited due to the electrical connection of the second type of metal layer and the third type of metal layer arranged on both sides of the second type of light-emitting layer; and so on. Therefore, various types of LEDs emit light separately without affecting each other. In addition, the micro gap in the light-emitting layer can release the stress inside the light-emitting layer and prevent it from warping without affecting the light-emitting efficiency of the light-emitting layer, thereby improving the product yield.

[0119] While the present invention 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 may be made therein without departing from the spirit and scope of the invention as defined by the following claims.

Claims

1. A method for manufacturing a multi-color luminous pixel unit, the method comprising: forming a stacked structure on a substrate, the stacked structure including, in order from bottom to top, a first metal layer, a first type of light-emitting layer, a second metal layer, and a second type of light-emitting layer; patterning the second type of light emitting layer and the second metal layer until a portion of the first type of light emitting layer is exposed; Selectively etching the stacked structure to form a first light emitting transistor and a second light emitting transistor, the first light emitting transistor including the first metal layer and the first type of light emitting layer, and the second light emitting transistor including the first metal layer, the first type of light emitting layer, the second metal layer, and the second type of light emitting layer; forming an isolation layer that continuously covers the entire first light emitting transistor and the entire second light emitting transistor; forming a first opening and a second opening in the isolation layer, the first opening exposing a portion of the first type of light emitting layer in the first light emitting transistor, and the second opening exposing a portion of the second type of light emitting layer in the second light emitting transistor; as well as A top electrode layer is formed that continuously covers the isolation layer, the entire first light-emitting transistor, and the entire second light-emitting transistor, and the top electrode layer contacts the first type of light-emitting layer in the first light-emitting transistor via the first opening and contacts the second type of light-emitting layer in the second light-emitting transistor via the second opening.

2. The method according to claim 1, wherein forming the stacked structure on the substrate comprises: forming the first metal layer and the first type of light emitting layer on the substrate from bottom to top; forming a first metal bonding layer on top of the first type of light emitting layer; forming the second type of light emitting layer and the second metal bonding layer on the first substrate from bottom to top; bonding the first metal bonding layer and the second metal bonding layer to form the second metal layer; as well as The first substrate is removed.

3. The method according to claim 2, wherein forming the first metal layer and the first type of light emitting layer on the substrate from bottom to top comprises: forming a third metal bonding layer on the substrate; forming the first type of light emitting layer and a fourth metal bonding layer on the second substrate from bottom to top from the first substrate; bonding the third metal bonding layer and the fourth metal bonding layer to form the first metal layer; as well as The second substrate is removed.

4. The method according to claim 2, further comprising: Prior to forming the first metal bonding layer on top of the first type of light emitting layer, the first type of light emitting layer is thinned.

5. The method according to claim 2, further comprising: The second type of light emitting layer is thinned.

6. The method according to claim 2, further comprising: A micro-gap structure is formed in at least one of the first type light emitting layer or the second type light emitting layer.

7. The method according to claim 2, further comprising: forming a micro-gap structure in both the first type of light-emitting layer and the second type of light-emitting layer, The micro-gap structure in the first type of light-emitting layer is staggered relative to the micro-gap structure in the second type of light-emitting layer.

8. The method according to claim 1, further comprising: The first metal layer and the second metal layer in the second light emitting transistor are electrically connected.

9. The method according to claim 8, wherein electrically connecting the first metal layer and the second metal layer in the second light emitting transistor comprises: removing a portion of the second type of light emitting layer in the second light emitting transistor to expose a top portion of the second metal layer in the second light emitting transistor; as well as An electrical connector is formed on an exposed top portion and sidewalls of the second metal layer in the second light emitting transistor and on sidewalls of the first type of light emitting layer and the first metal layer in the second light emitting transistor.

10. The method of claim 1, wherein the stacked structure further comprises a third metal layer formed on top of the second type of light emitting layer and a third type of light emitting layer formed on top of the third metal layer, the method further comprising patterning the third type of light emitting layer and the third metal layer until a portion of the second type of light emitting layer is exposed, and Selectively etching the stacked structure further includes selectively etching the stacked structure to form the first light-emitting transistor, the second light-emitting transistor and a third light-emitting transistor, the third light-emitting transistor including the first metal layer, the first type of light-emitting layer, the second metal layer, the second type of light-emitting layer, the third metal layer and the third type of light-emitting layer.

11. The method according to claim 10, wherein forming the stacked structure on the substrate comprises: forming the first metal layer, the first type of light-emitting layer, the second metal layer and the second type of light-emitting layer on the substrate from bottom to top; forming a first metal bonding layer on the second type of light emitting layer; forming the third type of light emitting layer and the second metal bonding layer on the substrate from bottom to top; bonding the first metal bonding layer and the second metal layer to form the third metal layer; and The substrate is removed.

12. The method according to claim 10, further comprising: At least one of the first type of light emitting layer, the second type of light emitting layer, or the third type of light emitting layer is thinned.

13. The method according to claim 10, further comprising: A micro-gap structure is formed in at least one of the first type light emitting layer, the second type light emitting layer, or the third type light emitting layer.

14. The method according to claim 10, further comprising: forming a micro-gap structure in all of the first type light-emitting layer, the second type light-emitting layer, and the third type light-emitting layer, wherein the microgap structure in the first type of light-emitting layer is staggered relative to the microgap structure in the second type of light-emitting layer, and The micro-gap structure in the second type of light-emitting layer is staggered relative to the micro-gap structure in the third type of light-emitting layer.

15. The method according to claim 10, further comprising: The first metal layer and the second metal layer in the second light emitting transistor are electrically connected, and the first metal layer, the second metal layer, and the third metal layer in the third light emitting transistor are electrically connected.

16. The method according to claim 15, wherein electrically connecting the first metal layer and the second metal layer in the second light emitting transistor and electrically connecting the first metal layer, the second metal layer, and the third metal layer in the third light emitting transistor comprises: removing a portion of the second type of light emitting layer in the second light emitting transistor to expose a top portion of the second metal layer in the second light emitting transistor; removing a portion of the third type light emitting layer in the third light emitting transistor, thereby exposing a top portion of the third metal layer in the third light emitting transistor; forming a first electrical connector on the exposed top and sidewalls of the second metal layer in the second light emitting transistor and on the sidewalls of the first type of light emitting layer and the first metal layer in the second light emitting transistor; as well as A second electrical connector is formed on the exposed top and sidewalls of the third metal layer in the third light emitting transistor and on the second type of light emitting layer, the second metal layer, the first type of light emitting layer and the sidewalls of the first metal layer in the third light emitting transistor.

17. The method according to claim 10, The top electrode layer continuously covers the entire third light emitting transistor.

18. The method according to claim 17, wherein The isolation layer continuously covers the entire third light emitting transistor; The method further includes forming a third opening in the isolation layer, the third opening exposing a portion of the third type of light emitting layer in the third light emitting transistor, and The top electrode layer contacts the third type of light emitting layer in the third light emitting transistor through the third opening.

Images