Patent Publication Number: US-2022238368-A1

Title: Transfer component and manufacturing method thereof, and transfer head

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/CN2020/121903, filed on Oct. 19, 2020 the entire disclosure of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to the field of mass transfer, and in particular to a transfer component and a manufacturing method thereof, and a transfer head. 
     BACKGROUND 
     A polydimethylsiloxane (PDMS) stamp is an important device used for micro-device mass transfer. At present, the PDMS stamp is mainly manufactured by etching a base plate to form a mold with multiple grooves and then injection molding PDMS in the mold. After the PDMS in the mold is cured, a PDMS with multiple bumps is taken out by rolling over the mold, where the PDMS with multiple bumps is a PDMS stamp with multiple bumps. 
     Obviously, quality of the PDMS stamp manufactured by this manufacturing scheme is directly related to quality of the mold, but the base plate for forming the mold is usually a sapphire base plate, where the sapphire substrate is difficult to be etched and has a small etch depth, which often leads to an insufficient depth-to-width ratio of the PDMS stamp, such that device transfer requirements cannot be met. Moreover, surfaces of the multiple grooves defined by etching are too rough, resulting in the same rough surfaces of the multiple bumps in the PDMS stamp, which reduces adhesion of the PDMS stamp in a device transfer process and affects a device transfer effect. 
     Therefore, how to manufacture a high-quality PDMS stamp that meets the device transfer requirements is an urgent problem to-be-solved. 
     SUMMARY 
     In a first aspect, a manufacturing method for a transfer component is provided in the disclosure. The method includes the following. An elastic adhesive layer is disposed on a surface of a substrate. A reticle is disposed on the elastic adhesive layer, where a hollow area is defined on the reticle. The elastic adhesive layer is etched through the hollow area of the reticle. The transfer component is obtained by removing the reticle after the etching is completed. 
     In a second aspect, a transfer component is further provided in the disclosure. The transfer component can be manufactured with any one of the foregoing manufacturing methods for a transfer component. 
     In a third aspect, a transfer head is further provided in the disclosure. The transfer head includes the transfer component above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a flow chart illustrating manufacturing of a polydimethylsiloxane (PDMS) stamp in the related art illustrated in the disclosure. 
         FIG. 2  is a schematic diagram illustrating a state change of each process when a PDMS stamp is manufactured in the related art. 
         FIG. 3  is a schematic structural diagram illustrating a PDMS stamp in the related art. 
         FIG. 4  is another schematic structural diagram illustrating a PDMS stamp in the related art. 
         FIG. 5  is a flow chart illustrating a manufacturing method for a transfer component provided in an optional implementation of the disclosure. 
         FIG. 6  is a schematic diagram illustrating a state change of each process in  FIG. 5 . 
         FIG. 7  is a schematic diagram illustrating a state change of a process of disposing a reticle on an elastic adhesive layer. 
         FIG. 8  is a flow chart illustrating arrangement of a reticle on an elastic adhesive layer. 
         FIG. 9  is another flow chart illustrating arrangement of a reticle on an elastic adhesive layer. 
         FIG. 10  is another schematic diagram illustrating a state change of a process of disposing a reticle on an elastic adhesive layer. 
         FIG. 11  is a flow chart illustrating a manufacturing method for a transfer component provided in another optional implementation of the disclosure. 
         FIG. 12  is a schematic diagram illustrating a state change of each process in  FIG. 11 . 
     
    
    
     Description of reference signs of the accompanying drawings:  20 —sapphire base plate;  200 —groove;  21 —PDMS stamp;  60 —substrate;  61 —elastic adhesive layer;  62 —reticle;  621 —reticle sacrificial layer;  622 —reticle basic layer;  63 —transfer component;  70 —reticle-manufacturing base plate;  71 —photoresist layer;  101 —photoresist layer;  120 —sapphire base plate;  121 —gallium nitride-based (GaN-based) epitaxial layer;  122 —silicon dioxide (SiO 2 ) layer;  123 —photoresist layer;  124 —sapphire substrate;  125 —PDMS layer. 
     DETAILED DESCRIPTION 
     In order to facilitate understanding of the present disclosure, a detailed description will now be given with reference to relevant accompanying drawings. The accompanying drawings illustrate some examples of implementations of the present disclosure. However, the present disclosure can be implemented in many different forms and is not limited to the implementations described herein. On the contrary, these implementations are provided for a more thorough and comprehensive understanding of the present disclosure. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art of the present disclosure. The terms used herein in the disclosure are for the purpose of describing implementations only and are not intended to limit the disclosure. 
     The following will simply describe a process of manufacturing a polydimethylsiloxane (PDMS) stamp in the related art with a combination of a flow chart as illustrated in  FIG. 1  and a schematic diagram for a state change of each process as illustrated in  FIG. 2 . 
     At S 102 , an injection mold is obtained by etching a sapphire base plate. 
     With a combination of  FIG. 2 ( a )  and  FIG. 2 ( b ) , multiple grooves  200  are defined on a sapphire base plate  20  by etching the sapphire base plate  20 . 
     At S 104 , PDMS is injection molded in the injection mold. 
     After the injection mold is formed by using the sapphire base plate  20 , liquid PDMS can be injection molded in the injection mold, to from a PDMS stamp  21 , as illustrated in  FIG. 2  ( c ). 
     At S 106 , a protective base plate is disposed on a PDMS layer. 
     A protective base plate  22  is similar to a release film of the PDMS stamp  21 , as illustrated in  FIG. 2( d ) . In some examples of the implementation, the protective base plate  22  may also be a sapphire base plate. 
     At S 108 , the injection mold is removed. 
     The injection mold can be removed after the PDMS stamp  21  is cured, as illustrated in  FIG. 2( e ) , such that the PDMS stamp  21  demolded is obtained. 
     It can be understood that, each bump in the PDMS Stamp  21  in  FIG. 2  has a flat surface and a longitudinal section shape of regular rectangle, which is an ideal condition of the manufacturing scheme in  FIG. 1 . In practice, there are usually problems at such aspects. 
     First of all, the sapphire base plate is difficult to be etched and usually has an etch depth that is difficult to exceed 10 microns (μm), and then a height of each bump in the PDMS Stamp  21  may also not exceed 10 μm. However, a difference of heights of three-color (red, green, and blue, RGB) light-emitting diode (LED) chips is usually greater than 5 μm when the three-color LED chips are transferred, so that a bump with a height of 10 μm is difficult to make up the difference of heights of the LED chips, resulting in a low chip transfer yield. 
     Then the sapphire base plate is prone to internal invasion when the sapphire base plate is etched, i.e., each of the multiple grooves defined by etching on the sapphire base plate has a gradually increasing cross section from notch to bottom as illustrated in  FIG. 3 , which may result in a problem that the PDMS and the injection mold are buckled with each other and thus the injection mold is difficult to be removed. 
     Furthermore, an etched surface formed by etching the sapphire base plate, i.e., a bottom of the groove, is rough and unsmooth, which may result in that a surface of the bump, of the PDMS stamp, for device adhering is rough and has low adhesion as illustrated in  FIG. 4 , thereby affecting a device transfer effect. 
     Based on the above, a solution is provided in the disclosure, to solve the above-mentioned technical problems. The solution will be explained in details in the following implementations. 
     In an optional implementation, a manufacturing method for a transfer component is provided in the implementation, referring to a flow chart as illustrated in  FIG. 5  and a schematic diagram as illustrated in  FIG. 6  for a state change of each process. 
     At S 502 , an elastic adhesive layer is disposed on a surface of a substrate. 
     With a combination of  FIG. 6 ( a )  and  FIG. 6 ( b ) , in the implementation, a substrate  60  may be a sapphire base plate. Of course, those skilled in the art can understand that, besides the sapphire base plate, the substrate  60  may also be a base plate or film structure made of other materials, such as a silicon dioxide (SiO 2 ) base plate, a silicon base plate, or the like. 
     An elastic adhesive layer  61  disposed on a surface of the substrate  60  can be pre-formed and then transferred to the surface of the substrate  60 , or can also be directly formed on the surface of the substrate  60 . In some examples, the elastic adhesive layer  61  can be formed by an injection molding process. 
     In some examples of the implementation, the elastic adhesive layer  61  may be a PDMS layer, and in this case, a transfer component manufactured is a PDMS stamp. Of course, those skilled in the art can understand that, a material of the elastic adhesive layer is not limited to PDMS. 
     At S 504 , a reticle is disposed on the elastic adhesive layer. 
     A reticle  62  is a patterned film layer that performs reticle and protection on the elastic adhesive layer  61 . It can be understood that, the reticle  62  has relatively concave patterns, and even in some examples, these patterns may also be hollow, e.g., as illustrated in  FIG. 6 ( c ) , the reticle  62  is a film layer with hollow areas. 
     Since relatively convex areas in the reticle  62  can protect corresponding areas in the elastic adhesive layer  61 , the corresponding areas in the elastic adhesive layer  61  are basically not etched, such that the relatively convex areas in the reticle  62  correspond to bumps in a transfer component finally manufactured. Supposing that the elastic adhesive layer  61  is etched in a certain etching manner, the reticle  62  generally may be insensitive to the certain etching manner, such that the reticle  62  can always protect the corresponding areas in the elastic adhesive layer  61  during etching of the elastic adhesive layer  61 . 
     In some examples of the implementation, as illustrated in  FIG. 7 , the reticle  62  includes a reticle basic layer  622  and a reticle sacrificial layer  621 , and the reticle sacrificial layer  621  is closer to the elastic adhesive layer  61  than the reticle basic layer  622  when the reticle  62  is disposed on the elastic adhesive layer  61 . Therefore, the reticle sacrificial layer  621  is attached to the elastic adhesive layer  61  and located between the elastic adhesive layer  61  and the reticle basic layer  622 . A material of the reticle basic layer  622  is different from that of the reticle sacrificial layer  621 , and roles of the reticle basic layer  622  and the reticle sacrificial layer  621  are also different as follows. 
     It can be understood that, the reticle basic layer  622  on the top of the reticle  62  is a really exposed layer, therefore during etching, the reticle basic layer  622  needs to protect the reticle sacrificial layer  621  and the elastic adhesive layer  61  each under the reticle basic layer  622 . That is, the reticle basic layer  622  during etching is required to be capable of playing a protective role of the reticle  62  to the elastic adhesive layer  61 , so that the reticle basic layer  622  may be insensitive to the etching manner for the elastic adhesive layer. In some examples of the implementation, the material of the reticle basic layer  622  may include but is not limited to gallium nitride (GaN). In an example of the implementation, a blue or green LED epitaxial layer grown can be directly used as the reticle basic layer  622 , i.e., a GaN-based epitaxial layer is directly used as the reticle basic layer  622 . Of course, those skilled in the art can understand that, the GaN-based epitaxial layer includes an N-type GaN layer, a quantum well layer, a P-type GaN layer, and other layer structures, but in fact, the reticle basic layer  622  is not required to have these layer structures and has no requirement on doping. In some examples, the reticle basic layer  622  may be an undoped GaN layer, and in other examples, the reticle basic layer  622  may be a GaN layer doped with silicon, a GaN layer doped with magnesium, or a GaN layer containing other doping sources. 
     The reticle sacrificial layer  621  is for that the reticle  62  can be removed in a subsequent process without damaging the transfer component, e.g., the reticle sacrificial layer  621  can react chemically with some solvents, but this chemical reaction may not affect the elastic adhesive layer, such that the transfer component can be separated from the reticle  62  without damaging the transfer component. In some examples of the implementation, the reticle sacrificial layer  621  may include but is not limited to at least one of a SiO 2  layer or a silicon nitride (Si 3 N 4 ) layer. 
     Of course, those skilled in the art can understand that, the reticle also may have a layer structure which is made of only one material, e.g., in an example, the reticle  62  is made of GaN, and according to the above introduction, a reticle of GaN can protect an area of the elastic adhesive layer covered by the reticle during etching of the elastic adhesive layer  61 . The reticle  62  can also be removed by laser decomposition when the transfer component is manufactured and the reticle needs to be peeled off. Moreover, a high-quality transfer component can also be obtained by appropriately controlling energy and time of laser irradiation on the reticle  62 . 
     In some examples of the implementation, the reticle  62  can be formed separately and then transferred onto the elastic adhesive layer  61 , referring to a flow chart of arrangement of a reticle on an elastic adhesive layer as illustrated in  FIG. 8 . 
     At S 802 , a reticle-manufacturing base plate and a reticle layer formed on the reticle-manufacturing base plate are provided. 
     In the implementation, a reticle-manufacturing base plate  70  may include but is not limited to a sapphire base plate. Since the reticle sacrificial layer  621  in the reticle  62  is closer to the elastic adhesive layer  61 , when the reticle  62  on the reticle-manufacturing base plate  70  is transferred onto the elastic adhesive layer  61 , a surface of the reticle  62  closing to the reticle-manufacturing base plate  70  may be away from the elastic adhesive layer  61 , and a surface of the reticle  62  away from the reticle-manufacturing base plate  70  may be attached to the elastic adhesive layer  61 . Therefore, when the reticle  62  is formed on the reticle-manufacturing base plate  70 , the reticle basic layer  622  is required to be formed on the reticle-manufacturing base plate  70  first, and then the reticle sacrificial layer  621  is required to be formed on the reticle basic layer  622 , where the reticle basic layer  622  and the reticle sacrificial layer  621  together constitute the reticle layer, with a combination of  FIG. 7 ( a )  to  FIG. 7 ( c ) . 
     In some examples of the implementation, a GaN layer may be temporarily grown on a sapphire base plate as the reticle basic layer  622 . In other examples of the implementation, a GaN-based epitaxial layer with the sapphire base plate can be provided directly. As such, a process that the reticle-manufacturing base plate is provided and the reticle basic layer  622  is formed on the reticle-manufacturing base plate  70  is omitted, facilitating improving a manufacturing efficiency of the reticle, and the GaN-based epitaxial layer can be manufactured by an LED chip manufacturer using a complete production line, avoiding overheads caused by a transfer component manufacturer purchasing a GaN-layer forming device, and reducing a production cost. 
     The reticle sacrificial layer  621  is formed by various processes which include but are not limited to any one of vacuum evaporating (EV), physical vapour deposition (PVD), or plasma enhanced chemical vapor deposition (PECVD). 
     At S 804 , the reticle layer is patterned to from the reticle. 
     A photolithography process can be used when the reticle layer is patterned, e.g., in some examples of the implementation, a photoresist layer  71  can be disposed on the reticle layer, as illustrated in  FIG. 7 ( d ) . A patterned photoresist layer  71  is obtained by exposing and developing the photoresist layer, referring to  FIG. 7 ( e ) . It can be understood that, before exposing the photoresist layer  71 , a patterned exposure reticle needs to be disposed on the photoresist layer  71  according to the characteristic of the photoresist layer  71  (e.g., positive photoresist or negative photoresist), where the photolithography process is more mature and thus will not be repeated herein. After the patterned photoresist layer  71  is obtained, a patterned reticle  62  can be obtained by etching the reticle layer under reticle of the photoresist layer  71 , as illustrated in  FIG. 7 ( f ) . A process of etching the reticle layer may include but is not limited to dry etching, wet etching, or the like. Generally, etching of the reticle layer may damage the photoresist layer  71  to some extent but may not etch all of the photoresist layer  71 , and the photoresist layer  71  is not a part of the reticle  62 , such that the patterned photoresist layer  71  needs to be removed after a reticle  62  with multiple hollow areas is obtained in the implementation, as illustrated in  FIG. 7 ( g ) . 
     At S 806 , the elastic adhesive layer is bound with the reticle. 
     The reticle sacrificial layer  621  of the reticle  62  may be exposed after the photoresist layer  71  is removed, as illustrated in  FIG. 7 ( g ) , in this case, a side of the reticle  62  can be disposed to be closer to the elastic adhesive layer  61  with the aid of the reticle-manufacturing base plate  70 , thereby adhering the reticle sacrificial layer  621  onto the elastic adhesive layer  61 , as illustrated in  FIG. 7 ( h ) . 
     At S 808 , the reticle-manufacturing base plate is removed. 
     The reticle-manufacturing base plate  70  needs to be removed after the reticle  62  is transferred onto the elastic adhesive layer  61 , as illustrated in  FIG. 7 ( i ) . In some examples of the implementation, since the reticle-manufacturing base plate  70  is a sapphire base plate and the reticle basic layer  622  is a GaN layer, when the reticle-manufacturing base plate  70  is separated from the reticle basic layer  622 , GaN can be decomposed by laser, and binding between the reticle-manufacturing base plate  70  and the reticle basic layer  622  can be damaged according to a principle of GaN→Ga+N 2 . 
     In some examples of the implementation, a wavelength of a laser used for decomposing the GaN layer may be selected randomly, e.g., in some examples, a laser with a wavelength of 266 nanometers (nm) can be selected to decompose the GaN layer. It can be understood that, it does not mean that a laser with a wavelength other than 266 nm definitely has a poor effect on decomposition of the GaN layer or is unable to be used for decomposition of the GaN layer, but because there already exists a laser device for emitting a laser with a wavelength of 266 nm, which is easy to be obtained. In fact, if a laser device for emitting a laser with a wavelength other than 266 nm is developed in the future, e.g., laser devices for emitting a laser with a wavelength of 255 nm, 258 nm, or 260 nm, these laser devices each can also be used. In other examples of the implementation, a laser with a wavelength of 355 nm can be selected to decompose the GaN layer. In the same way, if there are laser devices for emitting a laser with a wavelength of 354 nm, 356 nm, or 358 nm, these laser devices each can also be used. 
     In other examples of the implementation, the reticle  62  is directly formed on the elastic adhesive layer  61 , referring to another flow chart of arrangement of a reticle on the elastic adhesive layer  61  as illustrated in  FIG. 9 . 
     At S 902 , a reticle layer is disposed on the elastic adhesive layer. 
     Referring to  FIG. 10 ( a )  and  FIG. 10 ( b ) , since the reticle sacrificial layer  621  in the reticle  62  is closer to the elastic adhesive layer  61 , when the reticle  62  is directly formed on the elastic adhesive layer  61 , the reticle sacrificial layer  621  can be disposed on the elastic adhesive layer  61 , and then the reticle basic layer  622  can be disposed on the reticle sacrificial layer  621 , where the reticle sacrificial layer  621  and the reticle basic layer  622  together constitute the reticle layer. In other examples of the implementation, the reticle basic layer  622  can also be separately formed, and then the reticle sacrificial layer  621  can be formed on the reticle basic layer  622  by using one of EV, PVD, PECVD, or the like. Then a surface of the reticle sacrificial layer  621  away from the reticle basic layer  622  is adhered to the elastic adhesive layer  61  by using adhesiveness of the elastic adhesive layer  61 . Alternatively, the reticle sacrificial layer  621  can also be separately formed, then the reticle basic layer  622  can be formed on the reticle sacrificial layer  621 , and the reticle sacrificial layer  621  is bound with the elastic adhesive layer  61 . 
     In this scheme for disposing a reticle, in the same way, a GaN-based epitaxial layer pre-manufactured can be used as the reticle basic layer. For example, the GaN-based epitaxial layer is peeled off from its growth base plate by laser and then adhered onto the elastic adhesive layer  61 . Alternatively, the GaN-based epitaxial layer with the growth base plate is adhered onto the elastic adhesive layer  61 , and then the growth base plate is peeled off by laser. 
     At S 904 , the reticle layer is patterned to form the reticle. 
     The reticle layer can be patterned to form the reticle  62  after the reticle layer is disposed on the elastic adhesive layer  61 . In this scheme for directly forming the reticle  62  on the elastic adhesive layer  61 , the process of patterning the reticle layer is similar to a scheme that the reticle  62  is separately formed and then transferred to a PDMS layer i.e., the elastic adhesive layer  61 , which also includes the following. Dispose a photoresist layer  101  on the reticle layer, as illustrated in  FIG. 10 ( c ) , then a patterned photoresist layer  101  is obtained by exposing and developing the photoresist layer, as illustrated in  FIG. 10 ( d ) , after the patterned photoresist layer  101  is obtained, a patterned reticle  62  can be obtained by etching the reticle layer under reticle of the photoresist layer  101 , as illustrated in  FIG. 10 ( e ) , and the patterned photoresist layer  101  needs to be removed after the reticle  62  is obtained, as illustrated in  FIG. 10 ( f ) . 
     At S 506 , the elastic adhesive layer is etched through the hollow area of the reticle. 
     The elastic adhesive layer  61  can be etched under protection of the reticle  62  after the reticle  62  is disposed on the elastic adhesive layer  61 , as illustrated in  FIG. 6 ( d ) . It can be understood that, a process of etching the elastic adhesive layer  61  may include dry etching, wet etching, or the like. In some examples of the implementation, the elastic adhesive layer  61  can be dry etched by an inductively coupled plasma (ICP) manner. Optionally, at least one of oxygen (O 2 ), argon (Ar), or boron trifluoride (BCl 3 ) can be used to etch the elastic adhesive layer  61  when the elastic adhesive layer  61  is etched by the ICP manner. 
     There is no doubt that, a thickness of the reticle  62  and a thickness of the elastic adhesive layer  61  can be randomly set, such that a transfer component  63  with a greater depth-to-width ratio can be obtained by etching as needed. 
     At S 508 , the transfer component is obtained by removing the reticle after the etching is completed. 
     It can be understood that, the transfer component  63  is actually formed after the elastic adhesive layer  61  is etched, but in this case, the transfer component  63  is still a transfer component that has not yet separated from the reticle  62 . Therefore, for obtaining a separate transfer component  63 , the reticle  62  needs to be removed, as illustrated in  FIG. 6 ( e ) . As can be seen from  FIG. 6 ( e ) , the separate transfer component  63  includes the substrate  60  and the etched elastic adhesive layer  61 . The etched elastic adhesive layer  61  is disposed on the substrate  60 , and the etched elastic adhesive layer  61  is provided with multiple bumps  611  on a surface away from the substrate. 
     If the reticle  62  include the reticle sacrificial layer  621 , it can be considered to remove the reticle  62  in a way that the reticle sacrificial layer  621  can be removed without substantially damaging the transfer component  63 . For example, the elastic adhesive layer  61  and the reticle  62  can be put in a target solution, and the reticle sacrificial layer  621  of the reticle  62  can be corroded by using the target solution, thereby damaging the binding between the transfer component  63  and the reticle  62 . It can be understood that, the target solution has no effect on the elastic adhesive layer  61 , or a reaction speed of the target solution with the elastic adhesive layer  61  may also be less than or even far less than that of the target solution with the reticle sacrificial layer  621  even if the target solution can be chemically reacted with elastic adhesive layer  61 . 
     In some examples of the implementation, the reticle sacrificial layer  621  is made of SiO 2 , so that a buffered oxide etch (BOE) solution can be selected as the target solution. The elastic adhesive layer  61  and the reticle  62  are put in the BOE solution, to corrode the reticle sacrificial layer  621  of the reticle  62  by the BOE solution, thereby obtaining a separate and complete transfer component. 
     A transfer component is further provided in the implementation, where the transfer component can be manufactured based on the manufacturing method for a transfer component in any one of the foregoing examples. 
     The above transfer component is manufactured by disposing an elastic adhesive layer on a surface of a substrate, disposing a reticle provided with a hollow area on the elastic adhesive layer, and etching the elastic adhesive layer through the reticle, where the elastic adhesive layer is easy to be etched, such that the transfer component has a great depth-to-width ratio to be able to meet transfer requirements of various devices. In addition, since a surface of the transfer component for adhering to a device to-be-transferred is not an etched surface, the surface is more flat and has strong adhesion, thereby producing a better device transfer effect. Furthermore, since a process of manufacturing the transfer component is not related with a process that the transfer component is taken out by rolling over a mold, there is no such problem that the mold is difficult to be removed existed in the related art. Therefore, the transfer component provided in the disclosure not only has low difficulty in manufacturing process, but also is easy to be produced, which is beneficial to reducing a production cost. Moreover, the transfer component has excellent quality and meets transfer requirements, which is beneficial to improving an efficiency of device mass transfer. 
     In addition, a transfer head is further provided in the implementation, where the transfer head includes the transfer component. 
     The above transfer head includes the transfer component. During manufacturing, the transfer component is manufactured by disposing an elastic adhesive layer on a surface of a substrate, disposing a reticle provided with a hollow area on the elastic adhesive layer, and etching the elastic adhesive layer through the reticle, where the elastic adhesive layer is easy to be etched, such that the transfer component has a great depth-to-width ratio to be able to meet transfer requirements of various devices. In addition, since a surface of the transfer component for adhering to a device to-be-transferred is not an etched surface, the surface is more flat and has strong adhesion, thereby improving a device transfer effect of the transfer head. Furthermore, since a process of manufacturing the transfer component is not related with a process that the transfer component is taken out by rolling over a mold, there is no such problem that the mold is difficult to be removed existed in the related art. Therefore, the transfer head provided in the disclosure not only has low difficulty in manufacturing process, but also is easy to be produced, which is beneficial to reducing a production cost. Moreover, the transfer head has excellent quality and meets transfer requirements, which is beneficial to improving an efficiency of device mass transfer. 
     Considering the disadvantages of the related art mentioned above, in the disclosure, a polydimethylsiloxane (PDMS) stamp and a manufacturing method thereof are provided, which aims to solve problems that the PDMS stamp manufactured by a manufacturing scheme for a PDMS stamp in the related art cannot meet device transfer requirements and a device transfer effect is not good. A manufacturing method for a transfer component is provided in the disclosure. The method includes the following. An elastic adhesive layer is disposed on a surface of a substrate. A reticle is disposed on the elastic adhesive layer, where a hollow area is defined on the reticle. The elastic adhesive layer is etched through the hollow area of the reticle. The transfer component is obtained by removing the reticle after the etching is completed. 
     In the manufacturing method for a transfer component above, the elastic adhesive layer is disposed on the surface of the substrate, the reticle provided with the hollow area is disposed on the elastic adhesive layer, and the elastic adhesive layer is etched through the reticle. Compared with etching a sapphire base plate, etching the elastic adhesive layer is easier. Moreover, as long as the elastic adhesive layer is thick enough, a transfer component with a greater depth-to-width ratio can be obtained by etching, which can meet transfer requirements of various devices. In addition, since a surface of the transfer component for adhering to a device to-be-transferred is not an etched surface, the surface is more flat and has strong adhesion, thereby producing a better device transfer effect. Furthermore, since a process of manufacturing the transfer component is not related with a process that the transfer component is taken out by rolling over a mold, there is no such problem that the mold is difficult to be removed existed in the related art. Therefore, not only does the manufacturing method for a transfer component provided in the disclosure have low difficulty in a manufacturing process, but also the transfer component manufactured has excellent quality and meets the device transfer requirements, which is beneficial to improving an efficiency and yield of device mass transfer. 
     In the manufacturing method for a transfer component provided in the implementation, in which operations in the related art that an injection mold is obtained by etching a sapphire base plate, PDMS is injection molded in the injection mold, and a PDMS stamp is obtained by rolling over and removing the injection mold are abandoned, a reticle is disposed on an elastic adhesive layer, the elastic adhesive layer is directly etched under protection of the reticle, and a transfer component is obtained by removing the reticle. In the scheme provided in the implementation, there is no need to etch the sapphire base plate, but the elastic adhesive layer can be directly etched, where the elastic adhesive layer is less difficult to be etched and can obtain a greater depth-to-width ratio. For example, generally, a height of a bump in the transfer component may be greater than 50 μm, and a great depth-to-width ratio can better meet device transfer requirements. In this case, since a surface of the bump, in the transfer component, for adhering to a device to-be-transferred is not an etched surface, the surface of the bump for adhering to the device to-be-transferred is flat and has strong adhesion. Furthermore, the manufacturing scheme for a transfer component provided in the implementation is not related with a process of rolling over and removing the injection mold, therefore, there may be no difficulty in removing the mold due to internal invasion of grooves of the injection mold, which simplifies a manufacturing process of the transfer component, reduces a production difficulty of the transfer component, and improves quality of the transfer component. 
     In another optional implementation, in order to make those skilled in the art more clear about advantages and details of the foregoing manufacturing method for a transfer component, in this implementation, for example, an elastic adhesive layer is a PDMS layer, and the transfer component is a PDMS stamp, to illustrate a process of manufacturing the transfer component, referring to a flow chart as illustrated in  FIG. 11  with a combination of a schematic diagram of a state change of each process as illustrated in  FIG. 12 . 
     At S 1102 , a GaN-based epitaxial layer is obtained. 
     It can be understood that, the GaN-based epitaxial layer may be an epitaxial layer of a blue or green LED chip, which is a GaN layer grown on a sapphire base plate. Therefore, as illustrated in  FIG. 12 ( a ) , a blue or green LED epitaxial layer with the sapphire base plate can be directly selected, where a GaN-based epitaxial layer  121  is used as a reticle basic layer, and a sapphire base plate  120  can be used as a reticle-manufacturing base plate. 
     At S 1104 , a SiO 2  layer is formed on the GaN-based epitaxial layer. 
     In the implementation, a SiO 2  layer  122  is used as a reticle sacrificial layer, and in other examples of the implementation, the SiO 2  layer can be replaced by a Si 3 N 4  layer. 
     Optionally, the SiO 2  layer can be deposited by using a PECVD process when the SiO 2  layer is formed on the epitaxial layer  121 , as illustrated in  FIG. 12 ( b ) . 
     At S 1106 , a photoresist layer is disposed on the SiO 2  layer. 
     With a combination of  FIG. 12 ( c ) , in this example, a photoresist material for forming a photoresist layer  123  may be a positive photoresist or a negative photoresist. 
     At S 1108 , the photoresist layer is patterned by exposing and developing the photoresist layer. 
     There is no doubt that, before exposing the photoresist layer  123 , a corresponding exposure reticle further needs to be disposed on the photoresist layer  123  according to whether the photoresist layer  123  is a positive photoresist layer or a negative photoresist layer, which will not be illustrated in details. The photoresist layer  123  is patterned after exposing and developing the photoresist layer  123 , as illustrated in  FIG. 12 ( d ) . 
     At S 1110 , the SiO 2  layer and the GaN-based epitaxial layer are etched until the sapphire base plate in an etching area is exposed. 
     Referring to  FIG. 12 ( e ) , the SiO 2  layer  122  and the GaN-based epitaxial layer  121  can be etched sequentially under protection of the photoresist layer  123  after the photoresist layer  123  is patterned, thereby patterning the reticle layer. In the implementation, when the reticle layer is etched, the SiO 2  layer  122  and the GaN-based epitaxial layer  121  each exposed beyond the photoresist layer  123  are etched sequentially until the sapphire base plate is exposed. 
     At S 1112 , the photoresist layer is removed. 
     The photoresist layer  123  can be removed after the GaN-based epitaxial layer  121  and the SiO 2  layer  122  are etched, to expose the SiO 2  layer  122 , as illustrated in  FIG. 12 ( f ) . 
     At S 1114 , the PDMS layer is disposed on a sapphire substrate. 
     With a combination of  FIG. 12 ( g ) , in the implementation, a sapphire substrate  124  also is a sapphire base plate, where different terms of “base plate” and “substrate” are used here only in order to distinguish by name a sapphire base plate on which a PDMS layer  125  is carried from a sapphire base plate on which the epitaxial layer  121  is grown. 
     The PDMS layer  125  can be formed by an injection molding process. It needs to be noted that, in  FIG. 12 , the reticle is formed on the sapphire base plate  120 , and then the PDMS layer  125  is formed on the sapphire substrate  124 , but in other examples of the implementation, the two processes can be reversed in timing or can be performed simultaneously. 
     At S 1116 , the PDMS layer is used to adhere the SiO 2  layer. 
     In fact, the PDMS layer  125  is made of an organic silica gel and has adhesiveness, so that a surface of the PDMS layer  125  away from the sapphire substrate can be used to adhere to the SiO 2  layer  122 , as illustrated in  FIG. 12 ( h ) . The PDMS layer  125  can be bound with the SiO 2  layer  122  at low temperature, e.g., at room temperature, where the room temperature in the implementation ranges from 5° C. to 40° C. 
     At S 1118 , the sapphire base plate is removed by laser. 
     In the implementation, at least one of a laser with a wavelength of 266 nm or a laser with a wavelength of 355 nm can be used to irradiate the GaN-based epitaxial layer  121  from a side of the sapphire base plate  120 , to remove the sapphire base plate  120  by a laser lift-off (LLO) process, as illustrated in  FIG. 12 ( i ) . 
     At S 1120 , ICP dry etching is performed on the PDMS layer by using O 2 . 
     The PDMS layer  125  can be etched under protection of the reticle after the sapphire base plate  120  is removed, as illustrated in  FIG. 12 ( j ) . Since the PDMS layer  125  is made of an organic silica gel and thus can be etched by O 2 , in the implementation, the PDMS layer  125  can be etched by O 2  in the ICP dry etching manner, to form the PDMS stamp. It can be understood that, an etch depth can be controlled according to at least one of flow of O 2  or an etching duration, and the PDMS stamp can reach a greater depth-to width ratio on condition that the PDMS layer  125  is thick enough. 
     At S 1122 , the PDMS stamp is obtained by putting the PDMS layer in the BOE solution and removing the SiO 2  layer. 
     A semi-manufactured PDMS stamp can be put in the BOE solution after the PDMS layer  125  is etched, and then the SiO 2  layer  122  is melted and corroded by chemically reacting with the BOE solution, so that a PDMS stamp separated from the reticle is obtained, as illustrated in  FIG. 12 ( k ) . 
     The PDMS stamp manufactured in the implementation is mainly used to transfer a micro device including an LED chip, or the like. For example, in some examples of the implementation, the PDMS stamp manufactured can be used to transfer at least one of a red LED chip, a blue LED chip, or a green LED chip, where these LED chips may be flip chips or formal chips. Optionally, the LED chip includes but is not limited to a mini-LED, a micro-LED, an organic light-emitting diode (OLED), or the like. 
     The manufacturing method for a transfer component provided in the implementation has simple processes, and there is no situation that the PDMS stamp is difficult to be separated from the mold. Moreover, the PDMS stamp manufactured with the manufacturing method for a transfer component has a great depth-to-width ratio and a better transfer performance, which is beneficial to improving an efficiency and yield of device transfer and improve a production benefit. 
     It is to be understood that the disclosure is not to be limited to the disclosed implementations. Those of ordinary skill in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the protection scope of the appended claims of this disclosure.