Chip assembly, method of manufacturing the same, and mass transfer method

Abstract

The present application relates to a chip assembly, a method for manufacturing the same, and a mass transfer method. The chip assembly includes a substrate, an epitaxial structure disposed on the substrate, an inwardly retracted structure between the substrate and the epitaxial structure, the inwardly retracted structure having a smaller size than the epitaxial structure and being inwardly retracted relative to the epitaxial structure so that an edge of the epitaxial structure forms a gap with the substrate, and a passivation layer covering at least a portion of a surface of the epitaxial structure, the passivation layer not being connected to the substrate. In some implementations, the passivation layer does not cause additional resistance and does not break to form debris, and thus the success rate of the transfer is high.

Description

Technical Field

[0001] This application relates to the field of light-emitting chips, and more particularly to a chip component, a method for manufacturing the same, and a mass transfer method. Background Technology

[0002] Micro LED (Micro Light Emitting Diode) chips are shrunk to a fraction of the size of traditional LED chips. While offering superior performance, the miniaturization of Micro LED chips also increases manufacturing complexity. For example, their extremely small size and massive quantities make traditional picking and transferring methods impossible. Mass transfer technology, which involves accurately and inefficiently transferring large numbers of Micro LED chips onto circuit boards, is crucial for their effective application. However, mass transfer is prone to issues such as skewness and tipping, impacting production yield.

[0003] Therefore, ensuring the yield rate during the mass transfer of Micro LED chips is an urgent problem to be solved. Summary of the Invention

[0004] In view of the shortcomings of the above-mentioned related technologies, the purpose of this application is to provide a chip component and its manufacturing method as well as a mass transfer method, which aims to solve the problem of low yield during the mass transfer of Micro LED chips.

[0005] A chip component, comprising:

[0006] Substrate;

[0007] An epitaxial structure is disposed on the substrate;

[0008] An inward structure is located between the substrate and the epitaxial structure. The inward structure is smaller than the epitaxial structure and is inward relative to the epitaxial structure, so that the edge of the epitaxial structure forms a gap with the substrate.

[0009] A passivation layer covers at least a portion of the surface of the epitaxial structure, and the passivation layer is not connected to the substrate.

[0010] The passivation layer of the aforementioned chip assembly is not connected to the substrate. This prevents the fabricated light-emitting chip from experiencing additional resistance during transfer due to the passivation layer, and also prevents the passivation layer from breaking and forming debris, thereby improving the success rate of the light-emitting chip transfer.

[0011] Optionally, the indentation structure includes a bonding layer that bonds the epitaxial structure to the substrate.

[0012] By making the bonding layer smaller, an inward-shrinking structure is formed, which does not require modification of the epitaxial layer of the light-emitting chip and can ensure the quality of the light-emitting chip in some implementation processes.

[0013] Optionally, the inward structure includes a portion of the epitaxial structure near the substrate.

[0014] By utilizing a portion of the epitaxial structure to form the shrinkage structure, the shrinkage structure can be directly formed on the growth substrate during the fabrication process, and the light-emitting chip can be fabricated on the growth substrate without the need for additional transfer steps.

[0015] Based on the same inventive concept, this application also provides a method for manufacturing a chip component, comprising:

[0016] Provide substrate;

[0017] An inward-shrinking structure and an outward-shrinking structure are disposed on the substrate, wherein the size of the inward-shrinking structure is smaller than that of the outward-shrinking structure and is shrunken relative to the outward-shrinking structure, so that the edge of the outward-shrinking structure forms a gap with the substrate;

[0018] A passivation layer is formed, which covers at least a portion of the surface of the epitaxial structure and is not connected to the substrate.

[0019] Because the inward-shrinking structure creates a gap between the edge of the epitaxial structure and the substrate, the passivation material is not easily deposited into the interior of the gap when the passivation layer is formed. The above-mentioned chip assembly fabrication method can easily produce chip assemblies in which the passivation layer is separated from the substrate.

[0020] Optionally, the provision of the inward and outward structures on the substrate includes:

[0021] A bonding layer is disposed on the substrate as an inward shrinkage structure;

[0022] An epitaxial layer is grown on the growth substrate;

[0023] The epitaxial layer is transferred onto the substrate and the epitaxial structure is fabricated at the location corresponding to the indentation structure.

[0024] By using the bonding layer as an inward shrinkage structure, it can be applied to processes such as red Micro LED chips where the epitaxial layer is transferred from the growth substrate to other substrates before the epitaxial structure is fabricated. The resulting inward shrinkage structure ensures that the passivation layer on the epitaxial structure is not connected to the substrate, resulting in a high transfer success rate when transferring the light-emitting chip from the substrate to other targets.

[0025] Optionally, the step of setting a bonding layer on the substrate as a shrinkage structure includes:

[0026] A sacrificial layer is disposed on a substrate, and an opening is formed on the sacrificial layer to expose the substrate, the size of the opening being smaller than that of the epitaxial structure;

[0027] A bonding material is disposed in the opening of the sacrificial layer;

[0028] After transferring the epitaxial layer onto the substrate and fabricating the epitaxial structure at the location corresponding to the indentation structure, the method further includes:

[0029] Remove the sacrificial layer.

[0030] The bonding layer is placed in the opening of the sacrificial layer, which can better maintain the morphology during the transfer of epitaxial layers and the fabrication of epitaxial structures, thus ensuring yield.

[0031] Based on the same inventive concept, this application also provides a mass transfer method, comprising:

[0032] The chip component is manufactured using the above-described chip component manufacturing method;

[0033] A light-emitting chip is fabricated based on the aforementioned chip assembly;

[0034] The light-emitting chip is separated from the substrate to transfer the light-emitting chip in large quantities to the target substrate.

[0035] The aforementioned mass transfer method continues the fabrication of the light-emitting chip based on the aforementioned chip assembly to obtain the light-emitting chip and then mass transfers it. Since the passivation layer of the manufactured light-emitting chip is not connected to the substrate, there is no additional resistance caused by the passivation layer during the mass transfer process, and the passivation layer will not break and form debris, thus resulting in a high success rate of transfer. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of a chip component in the related technology;

[0037] Figure 2 This is a schematic diagram of a transfer-emitting chip in related technologies;

[0038] Figure 3 This is another schematic diagram of a transfer-emitting chip in related technologies;

[0039] Figure 4 This is a schematic diagram showing the state of the light-emitting chip after it has been transferred.

[0040] Figure 5 This is a schematic diagram of a chip assembly provided in an embodiment of this application;

[0041] Figure 6 Another schematic diagram of the chip assembly provided in the embodiments of this application;

[0042] Figure 7 A schematic flowchart illustrating the method for manufacturing a chip assembly provided in an embodiment of this application;

[0043] Figure 8 A detailed flowchart illustrating the manufacturing method of the chip assembly provided in the embodiments of this application;

[0044] Figure 9 This is another detailed flowchart illustrating the method for manufacturing a chip assembly provided in an embodiment of this application;

[0045] Figure 10 This is a further detailed flowchart illustrating the method for manufacturing a chip component provided in an embodiment of this application.

[0046] Figure 11 A flowchart illustrating the mass transfer method provided in an embodiment of this application;

[0047] Figure 12 A process diagram illustrating the fabrication process of the light-emitting chip provided in the embodiments of this application. Figure 1 ;

[0048] Figure 13 A process diagram illustrating the fabrication process of the light-emitting chip provided in the embodiments of this application. Figure 2 ;

[0049] Figure 14 A schematic diagram of the fabrication process of a light-emitting chip, provided as an embodiment of this application;

[0050] Explanation of reference numerals in the attached figures:

[0051] 100 - Light-emitting chip; 101 - Substrate; 102 - Epitaxial structure; 1021 - N-type semiconductor layer; 1022 - Active layer; 1023 - P-type semiconductor layer; 103 - Passivation layer; 1041 - P-type ohmic contact electrode; 1042 - N-type ohmic contact electrode; 105 - Void; 106 - Bonding layer; 107 - Sacrificial layer; 108 - Growth substrate; 1091 - P-type bonding electrode; 1092 - N-type bonding electrode; 200 - Target substrate; 201 - Bonding pad. Detailed Implementation

[0052] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0054] Micro LED chips in related technologies are prone to misalignment and tipping during mass transfer, which affects production yield.

[0055] Therefore, this application aims to provide a solution that can solve the above-mentioned technical problems, the details of which will be described in subsequent embodiments.

[0056] See Figure 1 The chip components in the related technologies typically include a substrate 101, an epitaxial structure 102, and a passivation layer 103. The epitaxial structure 102 is disposed on the substrate 101, and the passivation layer 103 is formed by covering the surface of the epitaxial structure 102 with an insulating passivation material to form protection.

[0057] The substrate 101 of the chip assembly can be a substrate 108, meaning the epitaxial structure 102 can be grown on this substrate 101; alternatively, it can be another substrate 101 not used for growing the substrate 108. The epitaxial structure 102 can be deposited onto the substrate 101 via over-transfer, or an epitaxial layer can be grown on the substrate 108 first, then transferred to the substrate 101 before fabricating the epitaxial structure 102. For example... Figure 1 In the example, the epitaxial structure 102 is not grown directly on the substrate 101, but is disposed on the substrate 101 through a bonding layer 106. The bonding layer 106 can be an adhesive material, such as BCB (benzocyclobutene) adhesive. In this application, the epitaxial layer refers to the deposited entire surface material, and the epitaxial structure 102 is the structure formed after etching and patterning the epitaxial layer. Typically, the epitaxial layer can form multiple independent epitaxial structures 102, and each epitaxial structure 102 can be fabricated as at least one light-emitting chip 100.

[0058] The epitaxial structure 102 includes, but is not limited to, an N-type semiconductor layer 1021, an active layer 1022, and a P-type semiconductor layer 1023, wherein the active layer 1022 is located between the N-type semiconductor layer 1021 and the P-type semiconductor layer 1023. The N-type ohmic contact electrode 1042 of the light-emitting chip 100 is connected to the N-type semiconductor layer 1021, and the P-type ohmic contact electrode 1041 is connected to the P-type semiconductor layer 1023. The specific structure and fabrication steps of the epitaxial structure 102 can be found in existing processes and will not be elaborated here.

[0059] The passivation layer 103 of the chip assembly needs to cover at least a portion of the surface of the epitaxial structure 102. During the formation of the passivation layer 103, passivation material needs to be deposited onto the surface of the epitaxial structure 102. In this process, passivation material may be deposited on both the substrate 101 and the exposed surfaces of the epitaxial structure 102. The passivation layer 103 formed on the epitaxial structure 102 is often connected to the substrate 101, for example... Figure 2 The circled part.

[0060] During chip transfer, the light-emitting chip 100 needs to be separated from the current substrate 101. Typically, processes such as laser separation are used to decompose or remove the adhesive between the epitaxial structure 102 and the substrate 101, allowing the epitaxial structure 102 to separate from the substrate 101. However, the passivation layer 103 is usually not affected; therefore, the passivation layer 103, connected to the substrate 101, forms a resistance during the transfer of the light-emitting chip 100. Figure 3 As shown, when transferring the light-emitting chip 100 to the target substrate 200, the connection between the passivation layer 103 and the substrate 101 needs to be broken. This also leads to situations where the light-emitting chip 100 is easily tilted, tipped over, or even unable to fall when it falls off the substrate 101 due to the pulling of the passivation layer 103, affecting the success rate of transferring the light-emitting chip 100. For example Figure 4 The light-emitting chip 100 became skewed during the transfer process. Figure 4 (Left 1, Left 2) and tilting ( Figure 4 The case of the one on the right. Also, see... Figure 3 When the passivation layer 103 connected to the substrate 101 breaks, the resulting debris will fall onto the target substrate 200. The debris may fall onto the pads 201, affecting the transfer of the light-emitting chip 100 or the yield of other subsequent processes.

[0061] This embodiment provides a chip assembly, whose substrate 101 and epitaxial structure 102 can be the same as those described above. See [link to previous documentation]. Figure 5 and Figure 6The chip assembly in this embodiment differs from the aforementioned examples in that the passivation layer 103 is not connected to the substrate 101. This prevents the fabricated light-emitting chip 100 from experiencing additional resistance during transfer due to the passivation layer 103, and also prevents the passivation layer 103 from breaking and forming debris. Furthermore, the chip assembly in this embodiment also includes a recessed structure disposed between the substrate 101 and the epitaxial structure 102. This recessed structure is smaller than the epitaxial structure 102 and is recessed relative to it. In other words, the projection of the recessed structure onto the substrate 101 is entirely within the projection of the epitaxial structure 102 onto the substrate 101. This prevents the edge of the epitaxial structure 102 from contacting the substrate 101, thus creating a gap 105. During the formation of the passivation layer 103, the gap 105 can provide a void area during the formation of the passivation layer 103. In some deposition processes, the passivation material has no sidewalls to attach to here and it is difficult to deeply cover the gap 105. Therefore, in some implementations, the passivation material is avoided from being deposited here, thereby ensuring that the passivation layer 103 deposited on the epitaxial structure 102 is not connected to the substrate 101.

[0062] Since the passivation material still maintains a certain angle during deposition, to avoid passivation material deposition on the sidewalls of the recessed structure, the size of the recessed structure can be selected according to the actual processing conditions in practical applications. Compared to the epitaxial structure 102, a smaller recessed structure is more likely to ensure that its sidewalls are not deposited with passivation material. For example, taking the fabrication of a Micro LED chip as an example, the size of the recessed structure can be 1-2 μm smaller than that of the epitaxial structure 102, providing both structural strength and sufficient clearance 105. In practical applications, the size of the recessed structure can be set according to different passivation layer 103 deposition processes and the size of the epitaxial structure 102 to avoid or reduce the deposition of passivation layer 103 within the clearance 105. In practical applications, the shape of the recessed structure is not limited; it can be the same as or different from the projection shape of the epitaxial structure 102 onto the substrate 101.

[0063] On the other hand, the deposition thickness of the passivation layer 103 in this embodiment can be less than the thickness of the inward structure, to prevent the passivation material deposited on the substrate 101 from connecting with the epitaxial structure 102 after being stacked up. Taking the fabrication of a Micro LED chip as an example, the thickness of the passivation layer 103 can be 5000 angstroms to 10000 angstroms, such as 5000 angstroms, 6000 angstroms, 7000 angstroms, 8000 angstroms, 9000 angstroms, etc.; the thickness of the inward structure can also be set to 5000 angstroms to 10000 angstroms, such as 5000 angstroms, 6000 angstroms, 7000 angstroms, 8000 angstroms, 9000 angstroms, etc., but greater than the thickness of the passivation layer 103, or the thickness of the inward structure can be selected to be more than 10000 angstroms, such as 11000 angstroms, 12000 angstroms, etc. In some implementations, raising the epitaxial structure 102 can ensure that the passivation layer 103 is not connected with the substrate 101.

[0064] In this embodiment, the recessed structure can be integrally formed with the epitaxial structure 102 of the chip; for example, it can be a part of the epitaxial structure 102. Alternatively, the recessed structure can be a part different from the epitaxial structure 102; for example, it can be a structure disposed between the substrate 101 and the epitaxial structure 102. See also... Figure 5 The epitaxial structure 102 of the light-emitting chip 100 is disposed on the substrate 101, and its portion near the substrate 101 is recessed to form a recessed structure. This recessed structure may include a buffer layer from the epitaxial layer grown on the substrate 101, or may include a portion of the N-type semiconductor layer 1021 or the P-type semiconductor layer 1023, or other layers. See also Figure 6 The epitaxial structure 102 is bonded to the substrate 101 by a bonding layer 106. The bonding layer 106 can be an adhesive material, such as BCB adhesive. By making the size of the bonding layer 106 relatively smaller, an inward structure is formed, which does not require modification of the epitaxial structure of the light-emitting chip 100 and can ensure the quality of the light-emitting chip 100 in some implementation processes.

[0065] In this embodiment, the chip assembly further includes an N-type ohmic contact electrode 1042 and a P-type ohmic contact electrode 1041, with the ohmic contact electrodes located on the side of the epitaxial structure 102 away from the substrate 101. When forming the passivation layer 103, the ohmic contact electrodes of the chip assembly may also be covered with a passivation layer 103. The passivation layer 103 at the ohmic contact electrodes can be removed by patterning, exposing the ohmic contact electrodes. The epitaxial structure 102 in this application includes, but is not limited to, the epitaxial structure 102 of a Micro LED chip. For example, it can also be a Mini LED (Mini Light Emitting Diode) chip or other LED (Light Emitting Diode) chips. Furthermore, the specific shape of the epitaxial structure 102 is not limited to the example of this embodiment. It is understood that as long as the passivation layer 103 is not connected to the substrate 101, the light-emitting chip 100 of any structure may have a relatively higher success rate when separated from the substrate 101.

[0066] This embodiment also provides a method for manufacturing a chip component, see [link to relevant documentation]. Figure 7 The method includes:

[0067] S101, Provide substrate;

[0068] S102. An inward shrinkage structure and an epitaxial structure are formed on the substrate;

[0069] The inner structure is smaller than the outer structure 102 and is recessed relative to the outer structure 102, so that the edge of the outer structure 102 forms a gap 105 with the substrate 101.

[0070] S103. Form a passivation layer that covers at least a portion of the surface of the epitaxial structure and is not connected to the substrate;

[0071] It should be understood that the above-described chip assembly manufacturing method can produce the chip assembly of the aforementioned example. Due to the shrinkage structure, a gap 105 is formed between the edge of the epitaxial structure 102 and the substrate 101. When the passivation layer 103 is formed, the passivation material is not easily deposited into the interior of the gap 105, thus ensuring the separation of the passivation layer 103 from the substrate 101.

[0072] It should be noted that the fabrication order of the inward-shrinking structure and the epitaxial structure 102 is not limited unless there is a conflict. In some embodiments, the inward-shrinking structure is a bonding layer 106 between the substrate 101 and the epitaxial structure 102. In this case, the bonding layer 106 can be first deposited on the substrate 101, and then the epitaxial layer or epitaxial structure 102 can be transferred to the substrate 101 and fixed by the bonding layer 106. See also Figure 8 As shown, the steps of forming the inward structure and the epitaxial structure 102 on the substrate 101 include:

[0073] S201. A bonding layer is formed on the substrate as an inward shrinkage structure;

[0074] S202, An epitaxial layer is grown on the growth substrate;

[0075] It should be understood that the growth substrate 108 in this example is a different substrate 101 from the substrate 101 used to fabricate the chip assembly. The method for growing the epitaxial layer can refer to existing solutions, and will not be elaborated upon in this embodiment.

[0076] S203. Transfer the epitaxial layer onto the substrate and fabricate the epitaxial structure at the position of the corresponding inward shrinkage structure;

[0077] In practical applications, the epitaxial layer can be fabricated into multiple epitaxial structures 102, and correspondingly, multiple shrinkage structures are formed on the substrate 101. After the epitaxial layer is transferred to the substrate 101, the epitaxial layer contacts the shrinkage structures on the substrate 101, that is, it contacts the bonding layer 106 to fix it on the substrate 101. Then, the epitaxial structures 102 are formed through processes such as etching. The position of each epitaxial structure 102 corresponds to the shrinkage structure, ensuring that the shrinkage structure is shrinkage relative to the fabricated epitaxial structure 102.

[0078] It is understood that the bonding layer 106 can be pre-formed with the required recessed shape before the epitaxial layer is transferred to the substrate 101, i.e., set according to the required size and shape. For example, a bonding material can be coated on the substrate 101, and the desired shape can be formed as the bonding layer 106 through patterning. In some embodiments, in order to better maintain the morphology of the bonding layer 106 during the transfer of the epitaxial layer and the fabrication of the epitaxial structure 102 to ensure yield, the morphology of the bonding layer 106 can be protected by providing a sacrificial layer 107. See [link to documentation]. Figure 9 As shown, the step of forming a bonding layer 106 as a shrinkage structure on the substrate 101 includes:

[0079] S301. A sacrificial layer is provided on a substrate, and an opening is formed on the sacrificial layer to expose the substrate, and the size of the opening is smaller than that of the epitaxial structure.

[0080] S302. Bonding material is placed in the opening of the sacrificial layer;

[0081] In practical applications, the thickness of the bonding material is not less than the thickness of the sacrificial layer 107 to ensure that the epitaxial layer can contact the bonding layer 106. In this example, the bonding material in the opening forms the bonding layer 106, and the thickness of the bonding material can also be slightly thicker. After the epitaxial layer is transferred, the excess bonding material can be extruded or removed in subsequent steps. After the epitaxial layer is transferred to the substrate 101, it contacts the bonding layer 106. Due to the presence of the sacrificial layer 107, the bonding layer 106 is always maintained in the opening of the sacrificial layer 107, and does not deform or collapse due to the transfer of the epitaxial layer, maintaining a good morphology, thereby helping to ensure production yield.

[0082] Following the process described above, after transferring the epitaxial layer onto the substrate 101 and fabricating the epitaxial structure 102 at the location corresponding to the indentation structure, the process further includes the step of removing the sacrificial layer 107.

[0083] In cases where the epitaxial structure 102 and the substrate 101 are not bonded by any other structure, such as when the epitaxial layer is grown directly on the substrate 101, the void 105 can be formed by etching the portion of the epitaxial structure 102 closest to the substrate 101 inwards. See also Figure 10 In some embodiments, the step of forming the inward structure and the epitaxial structure 102 on the substrate 101 includes:

[0084] S401, An epitaxial layer is grown on the substrate;

[0085] S402, to form an epitaxial structure from the epitaxial layer;

[0086] The method for growing the epitaxial layer and forming the epitaxial structure 102 can refer to existing schemes, and will not be described in detail in this embodiment.

[0087] S403, Laterally etch the region of the epitaxial structure close to the substrate to form the inward structure;

[0088] This implementation can directly form an inner shrinkage structure based on the epitaxial structure 102 without the need for additional transfer of the epitaxial layer, and can be applied to the fabrication process of some light-emitting chips 100.

[0089] In the fabrication process of the chip assembly described in the aforementioned example, a passivation layer 103, which is not connected to the substrate 101, is formed on the surface of the epitaxial structure 102. The fabrication method of the light-emitting chip 100 in this embodiment is based on this chip assembly to further complete the fabrication of the light-emitting chip 100 to obtain the light-emitting chip 100.

[0090] This embodiment provides a mass transfer method; see [link to relevant documentation]. Figure 11 The steps include, but are not limited to:

[0091] S501 provides chip components;

[0092] The chip assembly is manufactured using the chip assembly manufacturing method described in the aforementioned example.

[0093] S502, A light-emitting chip is fabricated based on chip components;

[0094] The process of fabricating a light-emitting chip 100 based on a chip assembly includes, but is not limited to, patterning the formed passivation layer 103 to expose the ohmic contact electrode covered by the passivation layer 103; and, in order to achieve better bonding, a bonding electrode connected to the ohmic contact electrode may also be provided on the epitaxial structure.

[0095] S503, Separate the light-emitting chip from the substrate to transfer the light-emitting chip in large quantities to the target substrate;

[0096] The light-emitting chip 100 is bonded to the substrate 101 through a bonding layer 106. The light-emitting chip 100 can be separated from the substrate 101 by decomposing the bonding layer 106 or by making the bonding layer 106 lose its adhesiveness. In the example where the epitaxial layer of the light-emitting chip 100 is grown from the substrate 101, the bonding interface between the light-emitting chip 100 and the substrate 101 can be decomposed by processes such as laser lift-off, so that the light-emitting chip 100 can be separated from the substrate 101.

[0097] Mass transfer of the light-emitting chip 100 can be a direct transfer, that is, placing the substrate 101 on the target substrate 200 with one side of the light-emitting chip facing the target substrate 200. After the light-emitting chip 100 separates from the substrate 101, it falls directly onto the target substrate 200 under the influence of gravity. In other examples, mass transfer of the light-emitting chip 100 can also be performed using a pick-up device such as a transfer substrate to pick up the light-emitting chip 100 from the substrate 101 and then place it onto the target substrate 200; since the passivation layer 103 is not connected to the substrate 101, the success rate of picking up the light-emitting chip 100 is also higher.

[0098] To better understand the fabrication process of the chip components and the fabrication and transfer process of the light-emitting chip 100 in this application, further explanation will be provided below with specific fabrication examples.

[0099] See Figure 12 This example uses a red-light Micro LED chip as an example. The fabrication process of the example light-emitting chip 100 includes, but is not limited to:

[0100] S1101. A sacrificial layer 107 is deposited on the substrate 101. The thickness of the sacrificial layer 107 can be 5000 angstroms to 10000 angstroms. In this example, the substrate 101 can be a transparent substrate such as a sapphire substrate. In practical applications, its material can also be flexibly selected according to requirements. The sacrificial layer 107 can be silicon oxide, which can be removed by wet etching, making it easy to operate. In practical applications, other materials can also be used.

[0101] S1102. The sacrificial layer 107 is patterned to create multiple openings. The size of the openings is slightly smaller than the size of the light-emitting chip 100, depending on the designed size of the light-emitting chip 100. In this example, the size of the openings is 1-2 μm smaller than the size of the epitaxial structure 102, that is, the edge of the opening is 1-2 μm from the edge of the epitaxial structure 102. In some examples, alignment marks can also be created on the surface of the substrate 101 to help with alignment during the transfer process.

[0102] S1103. A bonding material is disposed on this substrate 101, the thickness of which is slightly greater than the depth of the opening to ensure that the opening is completely filled. The bonding material in the opening serves as the bonding layer 106 for fixing the epitaxial layer. In this example, the bonding material can be BCB adhesive, which can be applied to the substrate 101 by spin coating or other methods.

[0103] S1104. An epitaxial layer is grown on the growth substrate 108. The epitaxial layer on the growth substrate 108 includes a P-type semiconductor layer 1023, an active layer 1022, and an N-type semiconductor layer 1021 in sequence. The epitaxial layer on the growth substrate 108 is bonded to the substrate 101 on which the bonding layer 106 is provided.

[0104] S1105. Remove the growth substrate 108 of the epitaxial layer, so that the epitaxial layer is transferred to the substrate 101 on which the bonding layer 106 is provided. At this time, the epitaxial layer is bonded to the substrate 101 by multiple bonding layers 106, and the sacrificial layer 107 ensures the morphology of these bonding layers 106.

[0105] S1106. Etch the epitaxial layer to form a mesa. During this process, the P-type semiconductor layer 1023 and the active layer 1022 at the mesa are etched, exposing the underlying N-type semiconductor layer 1021. In practical applications, a certain thickness of the N-type semiconductor layer 1021 at the mesa can also be etched away.

[0106] S1107. Fabricate an ohmic contact electrode, which includes an N-pole and a P-pole. The N-pole ohmic contact electrode is connected to the exposed N-type semiconductor layer 1021 at the mesa, and the P-pole ohmic contact electrode is connected to the P-type semiconductor layer 1023 on the side of the epitaxial layer away from the substrate 101.

[0107] Following the example above, see below. Figure 13 The fabrication process of the example light-emitting chip 100 also includes, but is not limited to:

[0108] S1108. The epitaxial layer is divided into multiple independent epitaxial structures 102, and etched from a direction perpendicular to the substrate 101 until the underlying sacrificial layer 107 is exposed. It should be understood that during this process, the etching position is controlled to ensure that the bonding layer 106 is recessed relative to the epitaxial structure 102, so that the bonding layer 106 is a recessed structure.

[0109] S1109. Remove the sacrificial layer 107. The removal method can be wet etching. After the sacrificial layer 107 is removed, a gap 105 is formed between the epitaxial structure 102 and the substrate 101.

[0110] S1110. A passivation layer 103 is deposited on the epitaxial structure 102 by chemical vapor deposition. The recessed gap 105 has a certain depth, and the passivation material deposited by chemical vapor deposition cannot penetrate deep into the interior of the gap 105. Therefore, the passivation layer 103 on the epitaxial structure 102 stops at the gap 105 and is not connected to the substrate 101. The remaining parts of the epitaxial structure 102, such as the side surfaces and the surface away from the substrate 101, can be covered by the passivation layer 103. During this process, passivation material may also be deposited on the substrate 101, but this passivation material is not connected to the epitaxial structure 102, and therefore will not adversely affect the transfer of the light-emitting chip 100. In other examples, physical vapor deposition can also be used to set the passivation layer 103. Since the coverage performance of physical vapor deposition is weaker than that of chemical vapor deposition, the passivation material is less likely to deposit inside the gap 105, making it easier to ensure that the passivation layer 103 is not connected to the substrate 101.

[0111] S1111. Etch the passivation layer 103 to expose the ohmic contact electrode on the epitaxial structure 102 for power supply connection. In this example, only the top of the ohmic contact electrode, i.e., the side away from the substrate 101, may be exposed.

[0112] S1112. A bonding electrode is formed at the location where the ohmic contact electrode is exposed in the passivation layer 103. The bonding electrode is connected to the ohmic contact electrode through an opening formed by removing the passivation layer 103. Specifically, the P-type bonding electrode 1091 is connected to the P-type ohmic contact electrode 1041, and the N-type bonding electrode 1092 is connected to the N-type ohmic contact electrode 1042. In this example, the bonding electrode may be larger than the ohmic contact electrode, and a portion of it may be disposed on the passivation layer 103.

[0113] After the fabrication of the light-emitting chip 100 is completed, when it needs to be transferred, a laser can be used to irradiate the bonding layer 106 through the substrate 101, causing the BCB adhesive to decompose and thus separating the light-emitting chip 100 from the substrate 101. In practical applications, other materials that can be decomposed or debonded by lasers or other conditions can also be used as bonding materials. For example, the mass transfer process can be referred to... Figure 2 The illustration shows that the light-emitting chip 100 is replaced with the structure fabricated in this example, that is, its passivation layer 103 is not connected to the substrate 101; after the light-emitting chip 100 is separated from the substrate 101, it falls onto the pad 201 of the target substrate 200 under the action of gravity. In this example, the light-emitting chip 100 is transferred from the growth substrate 108 to the substrate 101 on which the bonding layer 106, which is provided as an inward shrinkage structure, is provided during the fabrication process. The formed inward shrinkage structure enables the passivation layer 103 on the epitaxial structure 102 to be disconnected from the substrate 101, resulting in a high transfer success rate when transferring the light-emitting chip 100 from the substrate 101 to other targets.

[0114] This embodiment also provides an example, taking the fabrication and transfer process of a blue-green Micro LED chip as an example. The blue-green Micro LED chip can be directly fabricated on the growth substrate 108 to form an epitaxial structure 102 and a light-emitting chip 100. See also... Figure 14 The fabrication process of the light-emitting chip 100 in this example includes, but is not limited to:

[0115] S1201. A substrate 101 is provided, and an epitaxial layer is grown on the substrate 101. The epitaxial layer sequentially includes an N-type semiconductor layer 1021, an active layer 1022, and a P-type semiconductor layer 1023. The portion of the N-type semiconductor layer 1021 near the substrate 101 may include a buffer layer, which provides better lattice matching for subsequent growth.

[0116] S1202, Etch the epitaxial layer to form a mesa; During this process, the P-type semiconductor layer 1023 and the active layer 1022 at the mesa are etched, exposing the underlying N-type semiconductor layer 1021. In practical applications, a certain thickness of the N-type semiconductor layer 1021 at the mesa can also be etched away.

[0117] S1203. Fabricate an ohmic contact electrode, which includes an N-pole and a P-pole. The N-pole ohmic contact electrode is connected to the exposed N-type semiconductor layer 1021 at the mesa, and the P-pole ohmic contact electrode is connected to the P-type semiconductor layer 1023 on the side of the epitaxial layer away from the substrate 101.

[0118] S1204. Divide the epitaxial layer into multiple independent epitaxial structures 102 and etch them from a direction perpendicular to the substrate 101 until the substrate 101 below is exposed.

[0119] S1205, Lateral etching is performed on the region of the epitaxial structure 102 near the substrate 101, forming a void 105 inward in the region of the epitaxial structure 102 near the substrate 101. In this step, the buffer layer is etched, and in some examples, other parts of the N-type semiconductor layer 1021 may also be etched to some extent.

[0120] The subsequent process is the same as described in S1110, S1111, and S1112, and will not be repeated here. After the light-emitting chip 100 is fabricated, it can be separated from the substrate 101 by laser lift-off for transfer. In this example, the light-emitting chip 100 forms an inward structure directly on the substrate 101 where the epitaxial layer is grown during the fabrication process. This allows the fabrication of the light-emitting chip 100 to be completed on the substrate 101 without additional transfer steps. The inward structure formed by lateral etching of the epitaxial structure 102 also ensures that the passivation layer 103 on the epitaxial structure 102 is not connected to the substrate 101, resulting in a high transfer success rate when transferring the light-emitting chip 100 from the substrate 101 to other targets.

[0121] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A chip assembly, characterized in that, include: Substrate; An epitaxial structure is disposed on the substrate; An inward structure is located between the substrate and the epitaxial structure. The inward structure is smaller than the epitaxial structure and is inward relative to the epitaxial structure, so that the edge of the epitaxial structure forms a gap with the substrate. A passivation layer covers at least a portion of the surface of the epitaxial structure, and the passivation layer is not connected to the substrate; The inward structure includes the portion of the epitaxial structure near the substrate.

2. The chip assembly as described in claim 1, characterized in that, The inward structure further includes a bonding layer that bonds the epitaxial structure to the substrate.

3. The chip assembly as described in claim 1 or 2, characterized in that, The chip assembly also includes electrodes disposed on the epitaxial structure, the electrodes being disposed away from the substrate.

4. A method for manufacturing a chip component, characterized in that, include: Provide substrate; An inward-shrinking structure and an outward-shrinking structure are disposed on the substrate, wherein the size of the inward-shrinking structure is smaller than that of the outward-shrinking structure and is shrunken relative to the outward-shrinking structure, so that the edge of the outward-shrinking structure forms a gap with the substrate; A passivation layer is formed, the passivation layer covering at least a portion of the surface of the epitaxial structure and not connected to the substrate; The provision of the inward and outward structures on the substrate includes: An epitaxial layer is grown on the substrate; The epitaxial layer forms the epitaxial structure; The region of the epitaxial structure near the substrate is etched laterally to form the indentation structure.

5. The method for manufacturing a chip assembly as described in claim 4, characterized in that, The provision of the inward and outward structures on the substrate further includes: A bonding layer is disposed on the substrate as an inward shrinkage structure; An epitaxial layer is grown on the growth substrate; The epitaxial layer is transferred onto the substrate and the epitaxial structure is fabricated at the location corresponding to the indentation structure.

6. The method for manufacturing a chip assembly as described in claim 5, characterized in that, The provision of a bonding layer on the substrate as an inward structure includes: A sacrificial layer is disposed on a substrate, and an opening is formed on the sacrificial layer to expose the substrate, the size of the opening being smaller than that of the epitaxial structure; A bonding material is disposed in the opening of the sacrificial layer; After transferring the epitaxial layer onto the substrate and fabricating the epitaxial structure at the location corresponding to the indentation structure, the method further includes: Remove the sacrificial layer.

7. The method for manufacturing a chip assembly as described in any one of claims 4-6, characterized in that, The formation of the passivation layer includes: The passivation layer is formed by depositing passivation material onto the epitaxial structure using physical vapor deposition or chemical vapor deposition.

8. A mass transfer method, characterized in that, include: A chip assembly manufactured by the method of manufacturing a chip assembly according to any one of claims 4-7 is provided; A light-emitting chip is fabricated based on the aforementioned chip assembly; The light-emitting chip is separated from the substrate to transfer the light-emitting chip in large quantities to the target substrate.

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