A temporary wafer bonding method

Abstract

A wafer temporary bonding method relates to the field of microelectronics technology. The method comprises: setting a first bonding adhesive layer on the bonding surface of a carrier wafer; depositing a sacrificial layer on the bonding surface of a device wafer; setting a second bonding adhesive layer on the surface of the sacrificial layer; bonding the carrier wafer and the device wafer through the first bonding adhesive layer and the second bonding adhesive layer; after processing on the bonded device wafer, separating the device wafer, the sacrificial layer and the second bonding adhesive layer from the carrier wafer; opening a plurality of through holes in the second bonding adhesive layer to expose the surface of the sacrificial layer; etching the through holes and side-digging the sacrificial layer to remove the second bonding adhesive layer. The above method can efficiently remove the temporary bonding adhesive on the surface of the device wafer, thereby improving the removal efficiency of the temporary bonding adhesive and the product yield.

Description

Technical Field

[0001] The invention relates to the field of microelectronics technology, and in particular to a wafer temporary bonding method. Background Art

[0002] Temporary bonding process is often used in the microelectronics manufacturing process. Its main operation is to temporarily bond the device wafer and the carrier wafer, so as to provide support and a stable environment for the subsequent related process operations on the device wafer, ensuring that the process can be carried out accurately and smoothly. The existing method usually temporarily bonds the device wafer and the carrier wafer through temporary bonding glue; after the device wafer and the carrier wafer are debonded, the temporary bonding glue on the surface of the device wafer and the surface of the carrier wafer is cleaned with a cleaning liquid.

[0003] However, with the continuous development of semiconductor technology and the increasing requirements for product performance and functions, the manufacturing process of device wafers after temporary bonding has become more and more complicated. In these complex processes, various acid and alkali solutions, organic reagents, etc. may be frequently used. In order to ensure that the temporary bonding glue can still maintain a good bonding state between the device wafer and the carrier wafer under complex process environments, the acid and alkali resistance and organic reagent resistance of the temporary bonding glue are further enhanced. Although this ensures the bonding stability during the process, when the bonding glue needs to be debonded and cleaned later, due to the strong corrosion resistance and other properties of the bonding glue, it is difficult for traditional cleaning methods and means to effectively destroy the bond between the bonding glue and the wafer, resulting in the temporary bonding glue being difficult to be successfully removed from the wafer surface. Summary of the invention

[0004] The object of the present invention is to provide a wafer temporary bonding method, which can efficiently remove the temporary bonding glue on the surface of the device wafer, thereby improving the removal efficiency of the temporary bonding glue and the product yield.

[0005] The embodiment of the present invention is achieved as follows:

[0006] One aspect of the present invention provides a wafer temporary bonding method, the method comprising:

[0007] Disposing a first bonding adhesive layer on the bonding surface of the carrier wafer;

[0008] depositing a sacrificial layer on the bonding surface of the device wafer;

[0009] Disposing a second bonding adhesive layer on the surface of the sacrificial layer;

[0010] Bonding the carrier wafer and the device wafer via a first bonding adhesive layer and a second bonding adhesive layer;

[0011] After processing on the bonded device wafer, the device wafer, the sacrificial layer and the second bonding adhesive layer are separated from the carrier wafer;

[0012] A plurality of through holes are formed in the second bonding adhesive layer to expose the surface of the sacrificial layer;

[0013] The second bonding glue layer is removed by etching the through hole and side-digging the sacrificial layer.

[0014] Optionally, before providing the second bonding adhesive layer on the surface of the sacrificial layer, the method further comprises:

[0015] A mesh film is provided on the surface of the sacrificial layer.

[0016] Optionally, a plurality of through holes are formed in the second bonding adhesive layer, including:

[0017] The mesh film is torn off along the stacking direction of the device wafer and the sacrificial layer to form a through hole in the second bonding adhesive layer that can expose the surface of the sacrificial layer.

[0018] Optionally, a plurality of through holes are formed in the second bonding adhesive layer, including:

[0019] The second bonding adhesive layer is laser cut to form a through hole capable of exposing the surface of the sacrificial layer.

[0020] Optionally, the mesh density of the mesh film gradually increases from outside to inside along the radial direction.

[0021] Optionally, the mesh holes of the mesh membrane are at least one of circular holes, square holes, and triangular holes.

[0022] Optionally, providing a first bonding adhesive layer on the bonding surface of the carrier wafer includes: the first bonding adhesive layer is a thermosetting adhesive layer.

[0023] Optionally, disposing a second bonding adhesive layer on the surface of the sacrificial layer includes: the second bonding adhesive layer is a thermoplastic adhesive layer.

[0024] Optionally, depositing the sacrificial layer on the bonding surface of the device wafer includes: depositing the sacrificial layer on the bonding surface of the device wafer by chemical vapor deposition or physical vapor deposition.

[0025] Optionally, bonding the carrier wafer and the device wafer by using the first bonding adhesive layer and the second bonding adhesive layer includes: a bonding temperature of 200° C. to 300° C.

[0026] The beneficial effects of the present invention include:

[0027] The present invention provides a method for temporary bonding and separation of wafers, the method comprising: arranging a first bonding adhesive layer on the bonding surface of a carrier wafer; depositing a sacrificial layer on the bonding surface of a device wafer; arranging a second bonding adhesive layer on the surface of the sacrificial layer; the arrangement of the sacrificial layer facilitates the subsequent cleaning of the second bonding adhesive layer, which can avoid directly performing complex bonding adhesive removal operations on the wafer surface, reducing the risk of causing damage to the wafer itself, and also ensuring that the bonding adhesive can be efficiently removed. Bonding the carrier wafer and the device wafer through the first bonding adhesive layer and the second bonding adhesive layer can ensure that the wafers maintain a tight fit during the entire process, ensuring the stability of the processing process and product quality; after processing on the bonded device wafer, the device wafer, the sacrificial layer and the second bonding adhesive layer are separated from the carrier wafer; multiple through holes are opened in the second bonding adhesive layer to expose the surface of the sacrificial layer. Through the opening of the through holes, the position and range of etching and side digging can be accurately controlled, avoiding etching of unnecessary areas and reducing possible damage to other structures. At the same time, the efficiency of etching and side digging is also improved, which is conducive to more accurate removal of the bonding adhesive; the sacrificial layer is etched through the through holes and the side digging is removed to remove the second bonding adhesive layer. The above method can efficiently remove the temporary bonding adhesive on the surface of the device wafer, improve the removal efficiency of the temporary bonding adhesive and the product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 One of the flow diagrams of the wafer temporary bonding method provided by an embodiment of the present invention;

[0030] Figure 2 A second schematic flow chart of a wafer temporary bonding method provided by an embodiment of the present invention;

[0031] Figure 3 A third flow chart of a temporary wafer bonding method provided by an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of wafer bonding provided by an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of forming a through hole in the second bonding adhesive layer provided in an embodiment of the present invention;

[0034] Figure 6 A schematic diagram of etching a sacrificial layer through a through hole provided by an embodiment of the present invention.

[0035] Icon: 100 - carrier wafer; 120 - first bonding adhesive layer; 130 - device wafer; 140 - second bonding adhesive layer; 141 - through hole; 150 - mesh film; 160 - sacrificial layer. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0039] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0040] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0041] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] like Figure 1-Figure 3 As shown, the present invention provides a method for temporary wafer bonding and separation, and the bonding method includes the following steps:

[0043] S100, disposing a first bonding adhesive layer 120 on the bonding surface of the carrier wafer 100;

[0044] Specifically, in the semiconductor manufacturing process, the carrier wafer 100 is a key basic component, and before the first bonding adhesive layer 120 is provided, the bonding surface of the carrier wafer 100 needs to be carefully pre-treated, which includes using a chemical cleaning liquid to remove impurities and particles that may exist on the surface, so as to facilitate the adhesion of the first bonding adhesive.

[0045] When the first bonding adhesive layer 120 is actually provided, a spin coating process may be used to evenly distribute an appropriate amount of the first bonding adhesive solution on the bonding surface while the carrier wafer 100 is rotated at a high speed, and the first bonding adhesive solution is cured to form the first bonding adhesive layer 120 through a specific curing process, such as thermal curing or light curing. Figure 4 shown.

[0046] Optionally, the first bonding adhesive layer 120 is a thermosetting adhesive layer. Thermosetting adhesive is usually in a liquid or semi-liquid state before being cured, has good fluidity, and can be evenly spread on the bonding surface of the carrier wafer 100. The thermal stability of the thermosetting adhesive layer is also of great significance in the subsequent semiconductor manufacturing process. At the same time, since the thermosetting adhesive layer has thermal stability, during the subsequent high-temperature processes such as photolithography, etching, and ion implantation of the device wafer 130, the first bonding adhesive layer 120 can maintain its physical and chemical properties unchanged, and will not soften, decompose, or react adversely with other process materials due to high temperature, thereby ensuring that the bond between the device wafer 130 and the carrier wafer 100 is still strong, thereby improving product processing efficiency and product yield.

[0047] S200 , depositing a sacrificial layer 160 on the bonding surface of the device wafer 130 ;

[0048] S300, disposing a second bonding adhesive layer 140 on the surface of the sacrificial layer 160;

[0049] Specifically, before depositing the sacrificial layer 160, the bonding surface of the device wafer 130 needs to be pre-treated to remove impurities, particles, etc. that may exist on the bonding surface, so as to provide a good substrate for the deposition of the sacrificial layer 160. The size of the sacrificial layer 160 should be consistent with the size of the bonding surface of the device wafer 130 to ensure that the bonding surface of the device wafer 130 is completely covered.

[0050] It should be noted that, in one embodiment of the present application, the sacrificial layer 160 is deposited in a chemical vapor deposition or physical vapor deposition manner. By using the physical vapor deposition method, the deposition rate and thickness can be precisely controlled; by using the chemical vapor deposition method, high-quality sacrificial layer 160 deposition can be achieved at a relatively low temperature, which is very suitable for some temperature-sensitive device wafer 130 materials.

[0051] like Figure 4 As shown, the surface of the sacrificial layer 160 is provided with a second bonding adhesive layer 140. In order to ensure that the second bonding adhesive layer 140 is stably and evenly covered on the surface of the sacrificial layer 160, the second bonding adhesive solution should have good fluidity. Optionally, the second bonding adhesive layer 140 is a thermoplastic adhesive layer. Unlike a thermosetting adhesive layer, a thermoplastic adhesive layer can be reprocessed through some molding processes after being heated and softened. Such processability enables the second bonding adhesive layer 140 to efficiently and reliably form a through hole 141 and expose the surface of the sacrificial layer 160.

[0052] In addition, the present application does not impose any limitation on the specific deposition thickness of the sacrificial layer 160 , as long as it can separate the second bonding adhesive layer 140 and the device wafer 130 and facilitate the opening of multiple through holes 141 on its surface.

[0053] Step S400, bonding the carrier wafer 100 and the device wafer 130 through the first bonding adhesive layer 120 and the second bonding adhesive layer 140;

[0054] Specifically, during the bonding process, the optical alignment system can be used to ensure that the bonding surfaces of the carrier wafer 100 and the device wafer 130 are fully aligned to ensure that the first bonding adhesive layer 120 and the second bonding adhesive layer 140 can accurately contact each other. After the first bonding adhesive layer 120 and the second bonding adhesive layer 140 are aligned and in contact, the bonding system begins to heat up so that the thermosetting first bonding adhesive layer 120 and the thermoplastic second bonding adhesive layer 140 reach their respective appropriate operating temperature ranges. For the first bonding adhesive layer 120, heating can accelerate its curing reaction; for the second bonding adhesive layer 140, the temperature is raised to above its glass transition temperature to soften it. At the same time, the bonding system gradually increases the bonding pressure to ensure that the first bonding adhesive layer 120 and the second bonding adhesive layer 140 can bond and press the carrier wafer 100 and the device wafer 130 together.

[0055] Optionally, in the step of bonding the carrier wafer 100 and the device wafer 130 by the first bonding adhesive layer 120 and the second bonding adhesive layer 140 , the temperature is between 200° C. and 300° C.

[0056] At this point, the carrier wafer 100 and the device wafer 130 are bonded, and the carrier wafer 100 can provide mechanical support for the device wafer 130, making the entire structure more stable. In the subsequent semiconductor manufacturing process, the lithography, etching, deposition and other processes on the surface of the device wafer 130 can be more stable and accurate.

[0057] After the carrier wafer 100 has completed the manufacturing process, the carrier wafer 100 and the device wafer 130 need to be separated to obtain a device wafer 130 without bonding adhesive. The separation steps are as follows:

[0058] Step S500, after processing on the bonded device wafer 130, the device wafer 130, the sacrificial layer 160 and the second bonding adhesive layer 140 are separated from the carrier wafer 100;

[0059] Specifically, the first bonding adhesive layer 120 and the second bonding adhesive layer 140 can be separated by an appropriate amount of adhesive removal liquid, and at this time, the carrier wafer 100 and the device wafer 130 are separated. The first bonding adhesive layer 120 on the surface of the carrier wafer 100 can be removed by adhesive removal, etching, etc., so that the carrier wafer 100 can be reused.

[0060] The device wafer 130 , the sacrificial layer 160 and the second bonding adhesive layer 140 are still an integrated structure. In order to efficiently remove the second bonding adhesive, the second bonding adhesive layer 140 can be taken away by removing the sacrificial layer 160 which is easier to clean.

[0061] Step S600, opening a plurality of through holes 141 in the second bonding adhesive layer 140 to expose the surface of the sacrificial layer 160;

[0062] Specifically, in order to remove the sacrificial layer 160 disposed under the second bonding adhesive layer 140, it is necessary to open a plurality of through holes 141 in the second bonding adhesive layer 140 to expose the sacrificial layer 160. Figure 5 As shown. The present application does not impose any restrictions on the specific number and inner diameter of the through holes 141, and the specific number and inner diameter can be flexibly adjusted according to the size and thickness of the sacrificial layer 160. For example, for a larger device wafer 130, a larger number of through holes 141 may be required to ensure that the etching solution can evenly contact various parts of the sacrificial layer 160; and for a thicker sacrificial layer 160, the diameter of the through hole 141 may need to be appropriately increased to ensure etching efficiency.

[0063] Step S700 , etching through the through hole 141 to undercut the sacrificial layer 160 to remove the second bonding glue layer 140 .

[0064] Specifically, the sacrificial layer 160 may be etched by wet etching, and the etching solution used for wet etching may be selected according to the specific material of the sacrificial layer 160. Optionally, if the sacrificial layer 160 is a silicon dioxide layer, the etching solution may be a hydrofluoric acid solution.

[0065] like Figure 6 As shown, as the etching proceeds, the etching liquid not only etches the sacrificial layer 160 downward from the front of the through hole 141, but also gradually diffuses to the side of the sacrificial layer 160, forming a side-digging effect. During the side-digging process, the material on the side of the sacrificial layer 160 is gradually removed, so that the size of the sacrificial layer 160 in the horizontal direction gradually decreases. This change in the horizontal direction will affect the second bonding adhesive layer 140 disposed on the surface of the sacrificial layer 160. Since there is a certain adhesion between the second bonding adhesive layer 140 and the sacrificial layer 160 at the interface, as the sacrificial layer 160 is side-digging, the second bonding adhesive layer 140 loses support locally and falls off, thereby achieving the removal of the second bonding adhesive layer 140.

[0066] The present invention provides a method for temporary bonding and separation of wafers, the method comprising: setting a first bonding adhesive layer 120 on the bonding surface of a carrier wafer 100; depositing a sacrificial layer 160 on the bonding surface of a device wafer 130, and setting a second bonding adhesive layer 140 on the surface of the sacrificial layer 160; the setting of the sacrificial layer 160 facilitates the subsequent cleaning of the second bonding adhesive layer 140, which can avoid directly performing complex bonding adhesive removal operations on the wafer surface, reduce the risk of damaging the wafer itself, and also ensure that the bonding adhesive can be efficiently removed. The carrier wafer 100 and the device wafer 130 are bonded by the first bonding adhesive layer 120 and the second bonding adhesive layer 140, which can ensure that the wafers maintain a close fit during the entire process, ensuring the stability of the processing process and the product quality; the device wafer 130, the sacrificial layer 160 and the second bonding adhesive layer 140 are separated from the carrier wafer 100; a plurality of through holes 141 are opened in the second bonding adhesive layer 140 to expose the surface of the sacrificial layer 160. Through the opening of the through holes 141, the position and range of etching and side digging can be accurately controlled, avoiding etching of unnecessary areas, reducing possible damage to other structures, and also improving the efficiency of etching and side digging, which is conducive to more accurate removal of the bonding adhesive; the sacrificial layer 160 is etched and side-digging through the through holes 141 to remove the second bonding adhesive layer 140. The above method can efficiently remove the temporary bonding adhesive on the surface of the device wafer 130, improving the removal efficiency of the temporary bonding adhesive and the product yield.

[0067] For example, before step S300, in which the second bonding adhesive layer 140 is disposed on the surface of the sacrificial layer 160, there may be step S210, in which a mesh film 150 is disposed on the surface of the sacrificial layer 160. Figure 4 As shown, the mesh film 150 is disposed so as to be located between the sacrificial layer 160 and the second bonding adhesive layer 140 .

[0068] The mesh film 150 is a film layer with a certain hardness and has a plurality of mesh holes. The second bonding adhesive layer 140 disposed on the mesh film 150 can be connected to the sacrificial layer 160 through the mesh holes.

[0069] The arrangement of the mesh film 150 can facilitate the formation of a plurality of through holes 141 in the second bonding adhesive layer 140. For example, step S600, the method of opening a plurality of through holes 141 in the second bonding adhesive layer 140 to expose the surface of the sacrificial layer 160 includes:

[0070] Step S610 , tearing off the mesh film 150 along the stacking direction of the device wafer 130 and the sacrificial layer 160 to form a through hole 141 in the second bonding adhesive layer 140 that can expose the surface of the sacrificial layer 160 .

[0071] Specifically, since the mesh film 150 has a certain hardness, the mesh film 150 is torn off along the stacking direction of the device wafer 130 and the sacrificial layer 160 , so that the through holes 141 can be formed on the surface of the solid second bonding adhesive layer 140 .

[0072] It should be noted that, in one possible implementation of the present application, first, in order to facilitate lifting the edge of the mesh film 150 and tearing off the mesh film 150, the mesh density of the mesh film 150 gradually increases from the outside to the inside in the radial direction. This way, the mesh density at the periphery of the mesh film 150 is small, and the density of the mesh film 150 near the center area is large, so that it is easier to tear off the mesh film 150 from the edge of the mesh film 150.

[0073] Second, during the tearing process of the mesh film 150, a part of the second bonding adhesive layer 140 will be taken away, and the area corresponding to the mesh of the mesh film 150 will be left, so that the part of the second bonding adhesive layer 140 area taken away forms a through hole 141 that can expose the surface of the sacrificial layer 160. Among them, the present application does not impose any restrictions on the specific shape of the mesh of the mesh film 150, and the mesh is at least one of a circular hole, a square hole, and a triangular hole, as long as it can ensure that the through hole 141 that exposes the surface of the sacrificial layer 160 is formed.

[0074] Third, the existing wafer bonding method is usually to sequentially arrange a sacrificial layer, a bonding film, a second bonding adhesive layer, a first bonding adhesive layer and a carrier wafer on the device wafer, and the device wafer and the sacrificial layer are formed as a whole and temporarily bonded to the device wafer through the first bonding adhesive layer, the second bonding adhesive layer and the bonding film. Therefore, in the bonding process, it is necessary to consider the bonding force between the device wafer, the whole formed by the sacrificial layer and the bonding film, the bonding force between the bonding film and the second bonding adhesive layer, the bonding force between the second bonding adhesive layer and the first bonding adhesive layer, and the first bonding adhesive layer. The bonding force between the bonding adhesive layer and the supporting wafer results in a relatively weak bonding strength of the existing wafer. However, the present application, through the provision of the mesh film 150, can directly bond the whole formed by the device wafer 130 and the sacrificial layer 160 to the second bonding adhesive layer 140 through the multiple mesh holes of the mesh film 150. Compared with the existing wafer bonding method, the bonding between the whole formed by the device wafer 130 and the sacrificial layer 160 and the bonding film, and the bonding between the bonding film and the second bonding adhesive layer 140 are omitted, thereby maintaining the bonding strength.

[0075] In addition to the method of tearing off the mesh film 150 to open the through holes 141 on the second bonding adhesive layer 140, in another possible implementation of the present application, step S600, the method of opening a plurality of through holes 141 in the second bonding adhesive layer 140, further includes:

[0076] Step S620 , laser cutting the second bonding adhesive layer 140 to form a through hole 141 capable of exposing the surface of the sacrificial layer 160 .

[0077] Specifically, the laser cutting path is precisely planned and controlled by a computer control system to preset the shape, distribution density, and inner diameter of the through hole 141. During the cutting process, it is necessary to ensure that the moving speed of the laser beam is uniform and stable so that the hole wall of the through hole 141 is smooth and regular, which is convenient for sacrificing the layer 160 at the subsequent moment.

[0078] In order to further improve the cutting accuracy, an optical sensor or other detection device can be used to monitor the cutting depth, hole wall shape and other parameters in real time during the laser cutting process to ensure that the through hole 141 can accurately penetrate the second bonding adhesive layer 140 to expose the surface of the sacrificial layer 160 .

[0079] The above description is only an optional embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0080] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A wafer temporary bonding method, characterized in that: The method comprises: Disposing a first bonding adhesive layer on the bonding surface of the carrier wafer; depositing a sacrificial layer on the bonding surface of the device wafer; Disposing a second bonding adhesive layer on the surface of the sacrificial layer; Bonding the carrier wafer and the device wafer through the first bonding adhesive layer and the second bonding adhesive layer; After processing is performed on the bonded device wafer, the device wafer, the sacrificial layer and the second bonding adhesive layer are separated from the carrier wafer; A plurality of through holes are formed in the second bonding adhesive layer to expose the surface of the sacrificial layer; The sacrificial layer is etched through the through hole and side-excavated to remove the second bonding adhesive layer.

2. The wafer temporary bonding method according to claim 1, characterized in that: Before providing the second bonding adhesive layer on the surface of the sacrificial layer, the method further comprises: A mesh film is disposed on the surface of the sacrificial layer.

3. The wafer temporary bonding method according to claim 2, characterized in that: The step of opening a plurality of through holes in the second bonding adhesive layer comprises: The mesh film is torn off along the stacking direction of the device wafer and the sacrificial layer to form a through hole in the second bonding adhesive layer that can expose the surface of the sacrificial layer.

4. The wafer temporary bonding method according to claim 1, characterized in that: The step of opening a plurality of through holes in the second bonding adhesive layer comprises: The second bonding adhesive layer is laser cut to form a through hole capable of exposing the surface of the sacrificial layer.

5. The wafer temporary bonding method according to claim 2, characterized in that: The mesh density of the mesh film increases gradually from outside to inside along the radial direction.

6. The wafer temporary bonding method according to claim 2, characterized in that: The mesh holes of the mesh film are at least one of circular holes, square holes and triangular holes.

7. The wafer temporary bonding method according to claim 1, characterized in that: The step of providing a first bonding adhesive layer on the bonding surface of the carrier wafer includes: the first bonding adhesive layer is a thermosetting adhesive layer.

8. The wafer temporary bonding method according to claim 1, characterized in that: The step of disposing a second bonding adhesive layer on the surface of the sacrificial layer includes: the second bonding adhesive layer is a thermoplastic adhesive layer.

9. The wafer temporary bonding method according to claim 1, characterized in that: Depositing a sacrificial layer on the bonding surface of the device wafer includes: depositing a sacrificial layer on the bonding surface of the device wafer by chemical vapor deposition or physical vapor deposition.

10. The wafer temporary bonding method according to claim 1, characterized in that: The step of bonding the carrier wafer and the device wafer by using the first bonding adhesive layer and the second bonding adhesive layer includes: a bonding temperature of 200° C. to 300° C.

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