阅读说明：本技术 可用于微转移的微元件及其制作和转移方法、显示装置 (Micro-element capable of being used for micro-transfer, manufacturing method and transfer method thereof and display device ) 是由 江方 柯志杰 艾国齐 吴双 冯妍雪 于 2020-04-26 设计创作，主要内容包括：本发明提供了可用于微转移的微元件及其制作和转移方法、显示装置,其各所述LED芯粒倒挂悬空于所述未掺杂型半导体层的第一表面且通过沟槽相互隔离,各所述LED芯粒包括外延层及位于所述外延层朝向所述支撑衬底一侧的第一电极和第二电极；所述键合层设置于所述支撑衬底的表面并嵌入所述沟槽与所述未掺杂型半导体层形成连接,且所述键合层与各所述LED芯粒具有空气间隙；所述未掺杂型半导体层的第二表面设有若干个图形化区域,所述图形化区域作为微转移工艺的锚锭,在后续的转移工艺时,使得转印设备仅需要拉断锚锭与LED芯粒的连接即可实现LED芯粒的转印；同时还可避免锚锭对所述倒装LED芯粒的遮光。(The invention provides a micro-component capable of being used for micro-transfer, a manufacturing method and a transfer method thereof, and a display device, wherein L ED core particles are hung upside down on a first surface of an undoped semiconductor layer and are isolated from each other through a groove, each L ED core particle comprises an epitaxial layer, a first electrode and a second electrode, the first electrode and the second electrode are positioned on one side, facing a supporting substrate, of the epitaxial layer, a bonding layer is arranged on the surface of the supporting substrate and is embedded into the groove to be connected with the undoped semiconductor layer, the bonding layer and the L ED core particles are provided with air gaps, a plurality of patterning regions are arranged on a second surface of the undoped semiconductor layer, the patterning regions are used as anchor ingots of a micro-transfer process, when the subsequent transfer process is carried out, transfer printing of the L ED core particles can be realized only by pulling off connection of the anchor ingots and the L ED core particles by a transfer device, and meanwhile, the inverted L ED core particles can be prevented from being shielded from light.)

1. A micro-component useful for micro-transfer, comprising:

a support substrate;

the light-emitting structure comprises an undoped semiconductor layer and a plurality of L ED core particles which are arranged at intervals, wherein the undoped semiconductor layer comprises a first surface and a second surface which are opposite, the L ED core particles are hung upside down on the first surface of the undoped semiconductor layer and are isolated from each other through grooves, each L ED core particle comprises an epitaxial layer and a first electrode and a second electrode which are positioned on one side, facing the supporting substrate, of the epitaxial layer, the bonding layer is arranged on the surface of the supporting substrate and is embedded into the grooves to be connected with the undoped semiconductor layer, the bonding layer and each L ED core particle have an air gap, the second surface of the undoped semiconductor layer is provided with a plurality of graphical regions, and the graphical regions are used as anchor ingots of micro-transfer processes.

2. The micro-component of claim 1, wherein each of said L ED core particles comprises a protective layer covering a bare region of an epitaxial layer, said protective layer being received along sidewalls of said epitaxial layer to a first surface of said undoped semiconductor layer;

each of the patterned regions horizontally extends toward the adjacent flip L ED core particles centered at the intersection of two adjacent trenches, and the undoped semiconductor layer located between the adjacent L ED core particles serves as a chain of anchors.

3. The micro-component for micro-transfer according to claim 2, wherein the epitaxial layer comprises a first type semiconductor layer, an active layer and a second type semiconductor layer stacked in sequence along a first surface of the undoped semiconductor layer, a side surface of the second type semiconductor layer facing away from the active layer is provided with a transparent conductive layer, and the second electrode is stacked on a part of the surface of the transparent conductive layer; the first electrode is stacked on a partial region of the first type semiconductor layer.

4. A micro-component for micro-transfer according to claim 2, wherein the horizontal distance between two adjacent patterned areas is greater than 2 um.

5. The micro-component of claim 1, 2, 3 or 4, wherein the protective layer comprises a corrosion stop layer.

6. The micro-component of claim 1, wherein the undoped semiconductor layer has a thickness ranging from 0.5um to 2um, inclusive.

7. A method for manufacturing a micro-component for micro-transfer, said method comprising the steps of:

s01, providing a growth substrate;

s02, growing a light-emitting structure, wherein the light-emitting structure comprises an undoped semiconductor layer and an epitaxial layer which are sequentially stacked along the surface of the growing substrate, and the epitaxial layer comprises a first type semiconductor layer, an active layer and a second type semiconductor layer which are sequentially stacked along the surface of the undoped semiconductor layer;

s03, arranging a plurality of second electrode manufacturing areas on the surface of the second type semiconductor layer; etching the epitaxial layer to expose part of the first type semiconductor layer, thereby forming a plurality of first electrode manufacturing areas; the first electrode manufacturing area and the second electrode manufacturing area are arranged in an alignment mode;

s04, generating a plurality of grooves by etching part of the epitaxial layer, thereby forming a plurality of L ED core particles which are arranged at intervals;

s05, depositing a protective layer in the exposed area of each epitaxial layer, wherein the protective layer is laminated on the surface of each epitaxial layer except the first electrode manufacturing area and the second electrode manufacturing area and extends to the side wall of each epitaxial layer to be connected with the undoped semiconductor layer;

s06, forming a first electrode and a second electrode in each of the first electrode forming regions and the second electrode forming regions, respectively;

s07, manufacturing a sacrificial layer, wherein the sacrificial layer is deposited on the surface of each L ED core particle and the side wall of each groove;

s08, manufacturing a bonding layer, wherein the bonding layer covers the sacrificial layer and is embedded into each groove to be connected with the undoped semiconductor layer;

s09, providing a supporting substrate, and flip-chip bonding each L ED core particle to the supporting substrate;

s10, removing the growth substrate and exposing the undoped semiconductor layer;

s11, patterning the undoped semiconductor layer and etching the undoped semiconductor layer to part of the sacrificial layer along the vertical direction to form a plurality of patterned regions, wherein the patterned regions take the intersection point of two adjacent grooves as the center and horizontally extend to the peripheral inverted L ED core particles, and the sacrificial layer part bearing the surfaces of the undoped semiconductor layers is exposed;

s12, placing the flip-chip micro-component after the steps into an etching solution, and etching and removing the sacrificial layer through the etching solution, so that the flip-chip L ED core particles are arranged on the supporting substrate in an overhead mode.

8. The method of claim 7, wherein in step S11, the exposed area of the sacrificial layer is greater than or equal to 30%.

9. The method of claim 7, wherein the protective layer comprises a corrosion stop layer.

10. A method for manufacturing a micro-component for micro-transfer, said method comprising the steps of:

a01, providing a growth substrate;

a02, growing a light-emitting structure, wherein the light-emitting structure comprises an undoped semiconductor layer and an epitaxial layer which are sequentially stacked along the surface of the growing substrate, and the epitaxial layer comprises a first type semiconductor layer, an active layer and a second type semiconductor layer which are sequentially stacked along the surface of the undoped semiconductor layer;

a03, arranging a plurality of second electrode manufacturing areas on the surface of the second type semiconductor layer; etching the epitaxial layer to expose part of the first type semiconductor layer, thereby forming a plurality of first electrode manufacturing areas; the first electrode manufacturing area and the second electrode manufacturing area are arranged in an alignment mode;

a04, generating a plurality of grooves by etching part of the epitaxial layer, thereby forming a plurality of L ED core particles which are arranged at intervals;

a05, depositing a protective layer in the exposed area of each epitaxial layer, wherein the protective layer is laminated on the surface of each epitaxial layer except the first electrode manufacturing area and the second electrode manufacturing area and extends to the side wall of each epitaxial layer to be connected with the undoped semiconductor layer;

a06, forming a first electrode and a second electrode in each of the first electrode forming regions and the second electrode forming regions;

a07, patterning the protective layer and etching to part of the undoped semiconductor layer below the L ED core particles along the vertical direction to form a plurality of patterned regions, wherein the patterned regions horizontally extend to the adjacent L ED core particles by taking the intersection point of two adjacent grooves as the center and partially expose the undoped semiconductor layer below the L ED core particles;

a08, manufacturing a sacrificial layer, wherein the sacrificial layer is deposited on the surface of each L ED core particle and the side wall of each groove;

a09, manufacturing a bonding layer, wherein the bonding layer covers the sacrificial layer and is embedded into each groove to form connection with the undoped semiconductor layer;

a10, providing a supporting substrate, and flip-chip bonding each L ED core particle to the supporting substrate;

a11, removing the growth substrate and exposing the undoped semiconductor layer;

a12, placing the flip-chip micro-component after the steps in an etching solution, and etching and removing the sacrificial layer through the etching solution, so that each flip-chip L ED core particle is arranged on the supporting substrate in an overhead mode.

11. The method of claim 10, wherein the protective layer comprises a corrosion stop layer.

12. A transfer method for effecting mass transfer of microcomponents claimed in any one of claims 1 to 6, wherein said transfer method comprises positioning a chain of undoped semiconductor layers as anchors located between adjacent L ED core particles with said patterned regions as anchors to each of said anchors by means of a transfer device, thereby effecting mass transfer of said flip-chip microcomponents.

13. A display device formed by the transfer method according to claim 12.

Technical Field

The invention relates to the field of light emitting diodes, in particular to a micro-element for micro-transfer, a manufacturing method and a transfer method thereof, and a display device.

Background

Currently, the technology of Micro-pitch light emitting diode (Micro L ED) is becoming a popular research, and industry is expecting high-quality Micro-component products to enter the market, and the high-quality Micro-pitch light emitting diode products will have a profound impact on the traditional display products such as L CD/O L ED.

In the process of manufacturing microcomponents, the microcomponents are first formed on a donor substrate and then transferred to a receiving substrate. The receiving substrate is, for example, a display screen. One difficulty in manufacturing microcomponents is that: how to transfer the microcomponents from the donor substrate to the receiving substrate. In order to realize the mass transfer of the micro-components, many manufacturers transfer the micro-components to the circuit board by van der waals force through the micro-stamp transfer technology, so that the micro-component structure capable of being transferred is very important. The key point of the structure is in a suspended state with the micro-element and is separated from the supporting substrate, and the micro-element is bound with the substrate through the anchor structure; then the anchor ingot structure is broken by mechanical force to realize the mass transfer of the micro-element.

The currently proposed transferred micro-component structure, anchor structure, mainly comprises the following schemes: in the scheme 1, a chain layer is positioned on the surface of a light-emitting surface of a micro element; scheme 2, the chain layer is positioned on the side surface of the micro-element; scheme 3, the chain layer is positioned at the bottom of the micro-element; the structure schematic diagrams are respectively shown in figure 1, figure 2 and figure 3 of the attached drawings of the specification.

Wherein, the light-emitting of microelement can be influenced in the anchor structure setting that scheme one shows, and simultaneously, the roughness on its chain layer can direct influence picks up, and if damaged easily causes smudgy to the pick-up head on the chain layer.

The anchor structure shown in scheme two is generally arranged integrally with a PV (protective layer), and when the anchor structure is picked up, the chain layer is broken due to stress, so that the PV on the side wall of the device is easily broken, the protective effect of the side wall of the device is weakened, and the risk of electric leakage is greatly increased.

The anchor ingot structure shown in the third scheme is arranged, and the chain layer is arranged on the surface of the device, so that the surface of the device is easily polluted, and the subsequent bonding of the device is influenced.

In view of the above, the present inventors have specially designed a micro device for micro transfer, a method for manufacturing the same, a transfer method thereof, and a display device, and have developed the present application.

Disclosure of Invention

The invention aims to provide a micro-element for micro-transfer, a manufacturing method and a transfer method thereof, and a display device, so as to solve the problems caused by manufacturing an anchor structure in the micro-element in the prior art.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a micro-component useful for micro-transfer, comprising:

a support substrate;

the light-emitting structure comprises an undoped semiconductor layer and a plurality of L ED core particles which are arranged at intervals, wherein the undoped semiconductor layer comprises a first surface and a second surface which are opposite, the L ED core particles are hung upside down on the first surface of the undoped semiconductor layer and are isolated from each other through grooves, each L ED core particle comprises an epitaxial layer and a first electrode and a second electrode which are positioned on one side, facing the supporting substrate, of the epitaxial layer, the bonding layer is arranged on the surface of the supporting substrate and is embedded into the grooves to be connected with the undoped semiconductor layer, the bonding layer and each L ED core particle have an air gap, the second surface of the undoped semiconductor layer is provided with a plurality of graphical regions, and the graphical regions are used as anchor ingots of a micro-transfer process.

Preferably, each L ED core particle comprises a protective layer covering the exposed region of the epitaxial layer, the protective layer is connected to the first surface of the undoped semiconductor layer along the side wall of the epitaxial layer, each patterned region horizontally extends towards the adjacent inverted L ED core particle by taking the intersection point of two adjacent grooves as the center, and the undoped semiconductor layer positioned between the adjacent L ED core particles is used as a chain.

Preferably, the epitaxial layer comprises a first type semiconductor layer, an active layer and a second type semiconductor layer which are sequentially stacked along a first surface of the undoped type semiconductor layer, a transparent conducting layer is arranged on one side surface of the second type semiconductor layer, which is far away from the active layer, and the second electrode is stacked on part of the surface of the transparent conducting layer; the first electrode is stacked on a partial region of the first type semiconductor layer.

Preferably, the horizontal spacing of two adjacent patterned areas (i.e., two adjacent anchors) is greater than 2 um.

Preferably, the protective layer comprises a corrosion stop layer.

Preferably, the thickness of the undoped semiconductor layer ranges from 0.5um to 2um, inclusive.

Preferably, the sacrificial layer comprises SiO₂、SiN、Al₂O₃One or more of (a).

Preferably, the bonding layer comprises a metal or a silicon gel or an ultraviolet gel or a resin.

The invention provides a method for manufacturing a micro-element for micro-transfer, which comprises the following steps:

s01, providing a growth substrate;

s02, growing a light-emitting structure, wherein the light-emitting structure comprises an undoped semiconductor layer and an epitaxial layer which are sequentially stacked along the surface of the growing substrate, and the epitaxial layer comprises a first type semiconductor layer, an active layer and a second type semiconductor layer which are sequentially stacked along the surface of the undoped semiconductor layer;

s03, arranging a plurality of second electrode manufacturing areas on the surface of the second type semiconductor layer; etching the epitaxial layer to expose part of the first type semiconductor layer, thereby forming a plurality of first electrode manufacturing areas; the first electrode manufacturing area and the second electrode manufacturing area are arranged in an alignment mode;

s04, generating a plurality of grooves by etching part of the epitaxial layer, thereby forming a plurality of L ED core particles which are arranged at intervals;

s05, depositing a protective layer in the exposed area of each epitaxial layer, wherein the protective layer is laminated on the surface of each epitaxial layer except the first electrode manufacturing area and the second electrode manufacturing area and extends to the side wall of each epitaxial layer to be connected with the undoped semiconductor layer;

s06, forming a first electrode and a second electrode in each of the first electrode forming regions and the second electrode forming regions, respectively;

s07, manufacturing a sacrificial layer, wherein the sacrificial layer is deposited on the surface of each L ED core particle and the side wall of each groove;

s08, manufacturing a bonding layer, wherein the bonding layer covers the sacrificial layer and is embedded into each groove to be connected with the undoped semiconductor layer;

s09, providing a supporting substrate, and flip-chip bonding each L ED core particle to the supporting substrate;

s10, removing the growth substrate and exposing the undoped semiconductor layer;

s11, patterning the undoped semiconductor layer and etching the undoped semiconductor layer to part of the sacrificial layer along the vertical direction to form a plurality of patterned regions, wherein the patterned regions take the intersection point of two adjacent grooves as the center and horizontally extend to the peripheral inverted L ED core particles, and the sacrificial layer part bearing the surfaces of the undoped semiconductor layers is exposed;

s12, placing the flip-chip micro-component after the steps into an etching solution, and etching and removing the sacrificial layer through the etching solution, so that the flip-chip L ED core particles are arranged on the supporting substrate in an overhead mode.

Preferably, in step S11, the exposed area of the sacrificial layer is greater than or equal to 30%.

Preferably, the protective layer comprises a corrosion stop layer.

The invention also provides another manufacturing method of the micro-element for micro-transfer, which comprises the following steps:

a01, providing a growth substrate;

a02, growing a light-emitting structure, wherein the light-emitting structure comprises an undoped semiconductor layer and an epitaxial layer which are sequentially stacked along the surface of the growing substrate, and the epitaxial layer comprises a first type semiconductor layer, an active layer and a second type semiconductor layer which are sequentially stacked along the surface of the undoped semiconductor layer;

a03, arranging a plurality of second electrode manufacturing areas on the surface of the second type semiconductor layer; etching the epitaxial layer to expose part of the first type semiconductor layer, thereby forming a plurality of first electrode manufacturing areas; the first electrode manufacturing area and the second electrode manufacturing area are arranged in an alignment mode;

a04, generating a plurality of grooves by etching part of the epitaxial layer, thereby forming a plurality of L ED core particles which are arranged at intervals;

a05, depositing a protective layer in the exposed area of each epitaxial layer, wherein the protective layer is laminated on the surface of each epitaxial layer except the first electrode manufacturing area and the second electrode manufacturing area and extends to the side wall of each epitaxial layer to be connected with the undoped semiconductor layer;

a06, forming a first electrode and a second electrode in each of the first electrode forming regions and the second electrode forming regions;

a07, patterning the protective layer and etching to part of the undoped semiconductor layer below the L ED core particles along the vertical direction to form a plurality of patterned regions, wherein the patterned regions horizontally extend to the adjacent L ED core particles by taking the intersection point of two adjacent grooves as the center and partially expose the undoped semiconductor layer below the L ED core particles;

a08, manufacturing a sacrificial layer, wherein the sacrificial layer is deposited on the surface of each L ED core particle and the side wall of each groove;

a09, manufacturing a bonding layer, wherein the bonding layer covers the sacrificial layer and is embedded into each groove to form connection with the undoped semiconductor layer;

a10, providing a supporting substrate, and flip-chip bonding each L ED core particle to the supporting substrate;

a11, removing the growth substrate and exposing the undoped semiconductor layer;

a12, placing the flip-chip micro-component after the steps in an etching solution, and etching and removing the sacrificial layer through the etching solution, so that each flip-chip L ED core particle is arranged on the supporting substrate in an overhead mode.

Preferably, the protective layer comprises a corrosion stop layer.

The invention also provides a transfer method for realizing the mass transfer of the micro-component, which comprises the steps of taking the patterned area as an anchor, taking the undoped semiconductor layer positioned between the adjacent L ED core grains as a chain of anchors, and positioning to each anchor by a transfer device so as to realize the mass transfer of the flip-chip micro-component.

The invention also provides a display device which is manufactured and formed by adopting the transfer method.

According to the technical scheme, the light-emitting structure comprises an undoped semiconductor layer and a plurality of L ED core particles which are arranged at intervals, wherein the L ED core particles are hung upside down on the first surface of the undoped semiconductor layer and are mutually isolated through grooves, each L ED core particle comprises an epitaxial layer and a first electrode and a second electrode which are positioned on one side, facing the supporting substrate, of the epitaxial layer, the bonding layer is arranged on the surface of the supporting substrate and is embedded into the grooves to be connected with the undoped semiconductor layer, the bonding layer and each L ED core particle are provided with air gaps, the second surface of the undoped semiconductor layer is provided with a plurality of patterned regions which serve as anchor ingots of a micro-transfer process, the undoped semiconductor layer plays a supporting role for the L ED core particles in the suspended upside-down state, the second surface of the undoped semiconductor layer is provided with a plurality of patterned regions, and the LED core particles can be prevented from being connected with the LED core particles through pulling the patterned regions serving as anchor ingots during a subsequent transfer process, and the LED core particles can be prevented from being disconnected by pulling the anchor ingots 3875 ED core particles.

Based on the arrangement, the patterned regions can be directly used as the anchor, the undoped semiconductor layer positioned between the adjacent L ED core particles can be used as the anchor chain, so that the protective layer and the chain are not arranged in the same vertical direction, the influence on the protective layer on the side wall of the L ED core particle when the anchor is broken due to force can be further reduced in the subsequent transfer process, the electric leakage risk of the L ED core particle is avoided, and meanwhile, the breakage of the anchor can be better realized.

Secondly, a transparent conducting layer is arranged on one side surface of the second type semiconductor layer, which is far away from the active layer, and the second electrode is laminated on part of the surface of the transparent conducting layer, so that the current expansion of the second type semiconductor layer can be better realized.

Furthermore, the horizontal distance between two adjacent patterned areas (namely two adjacent anchor rods) is larger than 2um, so that the positioning and the chain breakage in the transfer process can be better realized.

The invention also provides a manufacturing method based on the micro-element structure, which is simple to operate and easy to realize while achieving the technical effects.

Furthermore, in the process of the graphical processing, the proportion of the exposed area of the sacrificial layer is more than or equal to 30 percent; the horizontal spacing between two adjacent patterned areas (i.e. two adjacent anchors) is greater than 2 um. The positioning and the chain fracture in the transfer process can be well realized while the hollowing of the subsequent sacrificial layer is ensured.

The invention also provides a transfer method based on the microelement structure, wherein the anchor ingot is adopted in the mass transfer process, the side wall of L ED core particles is protected, the chain can be well broken, and the positioning is accurate, the operation is simple, and the realization is easy.

The invention also provides a display device which is formed by adopting the transfer method and has simple structure and convenient operation and realization.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic view of a prior art structure in which a chain layer is located on the surface of a light-emitting surface of a micro-component;

FIG. 2 is a schematic diagram of a prior art structure in which a layer of chain bars is located on the side of a micro-component;

FIG. 3 is a schematic diagram of a prior art structure in which a layer of chain bars is located at the bottom of a microelement;

FIG. 4 is a schematic structural diagram of a micro-device for micro-transfer according to an embodiment of the present invention;

fig. 5.1 to 5.12 are schematic structural diagrams corresponding to the method for manufacturing a micro-device for micro-transfer according to an embodiment of the present invention;

fig. 6 is a top view of the structure after step S11 is performed in the method for manufacturing a micro-component for micro-transfer according to embodiment 1 of the present invention;

fig. 7 is a top view of another structure after step S11 is performed in the method for manufacturing a micro-component for micro-transfer according to embodiment 1 of the present invention;

fig. 8 is a top view of the structure after step a07 is performed in the method for manufacturing a micro-component for micro-transfer according to embodiment 2 of the present invention;

the symbols in the figure illustrate the horizontal spacing of B1, anchor, B2, L ED core particles, B3, hollow regions, B4, bonding layers, B5, supporting substrates, A1, L ED core particles, 1, growth substrates, 2, undoped semiconductor layers, 3, first type semiconductor layers, 4, active layers, 5, second type semiconductor layers, 6, transparent conducting layers, 7, protective layers, 8, second electrodes, 8-1, second electrode manufacturing regions, 9, first electrodes, 9-1, first electrode manufacturing regions, 10, sacrificial layers, 11, bonding layers, 12, supporting substrates, 13, grooves, 14, chains, 15, air gaps, L1 and two adjacent patterned regions (namely two adjacent anchor).

Detailed Description

In order to make the content of the present invention clearer, the content of the present invention is further explained below with reference to the attached drawings. The invention is not limited to this specific embodiment. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.