Wafer structure and cutting method of wafer structure
By setting a selective transmission film layer between the substrate and the dissociation film layer to block the first ray and transmit the second ray, the problem of laser cutting damaging the substrate is solved, the substrate can be reused and the wafer can be effectively separated, and the production cost is reduced.
Patent Information
- Application Number
- CN202510803686.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-16
- Publication Date
- 2025-09-16
AI Technical Summary
During the wafer cutting process, laser cutting will damage the substrate, resulting in the substrate being unable to be reused and increasing production costs.
A selective transmission film layer is provided between the substrate and the dissociation film layer to block the first ray and transmit the second ray, so as to protect the substrate from damage and realize effective separation of the wafer and the substrate.
The reuse rate of the substrate is improved, the production cost is reduced, and the effectiveness of wafer cutting and dissociation is ensured.
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Figure CN120657006A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a wafer structure and a method for cutting the wafer structure. Background Art
[0002] Wafer reassembly refers to cutting the chips (die) on the wafer (wafer) and reassembling the qualified chips (good dies) together to form a high-yield wafer structure.
[0003] During the wafer cutting process, the wafer needs to be bonded to the substrate, then laser cut, and then the dissociation process is performed to obtain a large number of chips. During the laser cutting process, the laser will cut into the substrate, making the substrate unable to be reused.
[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the Invention
[0005] In view of this, a wafer structure and a method for cutting the wafer structure are provided. The wafer structure forms a selective transmission film layer between the substrate and the dissociation film layer, which can protect the substrate when the wafer is reassembled.
[0006] Other features and advantages of the present disclosure will become apparent from the following detailed description, or may be learned in part by practice of the present disclosure.
[0007] According to one aspect of the present disclosure, there is provided a wafer structure, comprising:
[0008] substrate;
[0009] Selecting a transmissive film layer, located on the substrate;
[0010] a dissociation film layer, located on a side of the selective transmission film layer away from the substrate;
[0011] a bonding film layer, located on a side of the dissociation film layer away from the substrate;
[0012] a wafer bonded on the bonding film layer;
[0013] The selective transmission film layer is used to block the first ray and transmit the second ray, and the wavelength band of the first ray does not overlap with the wavelength band of the second ray;
[0014] The selective transmission film layer blocks the first ray from being irradiated from the wafer to the substrate; the second ray is irradiated from the substrate to the dissociation film layer through the selective transmission film layer.
[0015] In an exemplary embodiment of the present disclosure, the selective transmission film layer and the dissociation film layer are laminated together.
[0016] In an exemplary embodiment of the present disclosure, a protective film layer is further included, and the protective film layer is disposed between the selective transmission film layer and the dissociation film layer.
[0017] In an exemplary embodiment of the present disclosure, the selective transmission film layer is further disposed on a side of the protective film layer close to the substrate.
[0018] In an exemplary embodiment of the present disclosure, the selectively transmissive film layer includes a first sub-transmissive film layer and a second sub-transmissive film layer, wherein the first sub-transmissive film layer is located on a side of the protective film layer away from the substrate, and the second sub-transmissive film layer is located on a side of the protective film layer close to the substrate;
[0019] The thickness of the first sub-transmissive film layer is greater than or equal to the thickness of the second sub-transmissive film layer.
[0020] In an exemplary embodiment of the present disclosure, the shielding rate of the first sub-transmissive film layer to the first ray is greater than or equal to the shielding rate of the second sub-transmissive film layer to the first ray.
[0021] In an exemplary embodiment of the present disclosure, the transmittance of the second sub-transmitting film layer to the second ray is greater than or equal to the transmittance of the first sub-transmitting film layer to the second ray.
[0022] In an exemplary embodiment of the present disclosure, a reconstruction film layer is further included, and the reconstruction film layer is located between the substrate and the selective transmission film layer.
[0023] In an exemplary embodiment of the present disclosure, a stress adjustment film layer is further included, and the stress adjustment film layer is located between the substrate and the reconstruction film layer.
[0024] According to another aspect of the present disclosure, a method for cutting a wafer structure is provided, the method comprising:
[0025] S1. Provide a substrate;
[0026] S2. Forming a stacked structure on the substrate, the stacked structure comprising at least a selective transmission film layer, a dissociation film layer, and a bonding film layer sequentially formed in a direction perpendicular to the surface of the substrate; wherein the selective transmission film layer is configured to block a first ray and transmit a second ray, and the wavelength band of the first ray does not overlap with the wavelength band of the second ray;
[0027] S3, bonding a wafer on the bonding film layer;
[0028] S4, cutting the wafer using the first ray;
[0029] S5. Utilize the second ray to transmit the selective transmission film layer from the substrate to dissociate the dissociation film layer.
[0030] The wafer structure provided by the present disclosure sequentially forms a selective transmission film layer, a dissociation film layer and a bonding film layer on a substrate, and the wafer is bonded to the bonding film layer. When the wafer is cut, the selective transmission film layer can block the first ray used to cut the wafer, protecting the substrate from being damaged by the first ray, thereby improving the reuse rate of the substrate; in addition, after the wafer is cut, when the dissociation film layer is dissociated, the selective transmission film layer can transmit the second ray used for dissociation, thereby realizing effective separation of the wafer and the substrate and ensuring the integrity of the substrate.
[0031] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.
[0033] Figure 1 Schematic diagram of a wafer structure in an exemplary embodiment of the present disclosure.
[0034] Figure 2 In the exemplary embodiment of the present disclosure Figure 1 The schematic diagram of the wafer structure after cutting is shown.
[0035] Figure 3 In the exemplary embodiment of the present disclosure Figure 1 Schematic diagram of the incident direction of the second ray when the wafer structure is dissociated.
[0036] Figure 4 Schematic diagram of another wafer structure in an exemplary embodiment of the present disclosure.
[0037] Figure 5 In the exemplary embodiment of the present disclosure Figure 4 The schematic diagram of the wafer structure after cutting is shown.
[0038] Figure 6 In the exemplary embodiment of the present disclosure Figure 4 Schematic diagram of the incident direction of the second ray when the wafer structure is dissociated.
[0039] Figure 7 Schematic diagram of a wafer structure having a first sub-transmissive film layer and a second sub-transmissive film layer in an exemplary embodiment of the present disclosure.
[0040] Figure 8 Schematic diagram of another wafer structure having a first sub-transmissive film layer and a second sub-transmissive film layer in an exemplary embodiment of the present disclosure.
[0041] Figure 9 In the exemplary embodiment of the present disclosure Figure 8 The schematic diagram of the wafer structure after cutting is shown.
[0042] Figure 10 In the exemplary embodiment of the present disclosure Figure 8 Schematic diagram of the incident direction of the second ray when the wafer structure is dissociated.
[0043] Figure 11 Schematic diagram of the structure of a dissociated substrate in an exemplary embodiment of the present disclosure.
[0044] Figure 12 The present invention is a flowchart of a method for cutting a wafer structure in an exemplary embodiment of the present invention.
[0045] The description of the accompanying drawings is as follows:
[0046] 100, substrate; 210, selectively transmissive film layer; 211, first sub-transmissive film layer; 212, second sub-transmissive film layer; 220, dissociation film layer; 230, bonding film layer; 240, protective film layer; 250, reconstitution film layer; 260, stress regulation film layer; 300, wafer; X, first ray; Y, second ray. DETAILED DESCRIPTION
[0047] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent identical or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.
[0048] Although relative terms such as "upper" and "lower" are used in this specification to describe the relationship of one illustrated component to another, these terms are used herein for convenience only, such as in accordance with the orientation of the illustrations in the accompanying drawings. It will be understood that if the illustrated device were flipped upside down, the component described as "upper" would become the component "lower." When a structure is referred to as "on" another structure, this may mean that the structure is integrally formed with the other structure, that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via the other structure.
[0049] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express open-ended inclusion and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used only as labels and are not intended to limit the quantity of their objects.
[0050] In related technologies, in advanced packaging technology, wafer reorganization usually adopts laser cutting process to divide the wafer into multiple dies (chips) along the cutting path, thereby screening out unqualified chips and reorganizing qualified chips to form a high-yield wafer structure, which is conducive to the subsequent stacking process.
[0051] Currently, as device miniaturization requirements increase, wafer thickness is also decreasing, typically less than 100μm. During the reassembly process, a substrate is required to support the wafer before laser dicing. After dicing, the substrate is separated from the wafer through processes such as dissociation and cleaning. However, laser dicing damages the wafer carrier, making it unusable and increasing production costs.
[0052] Based on this, the embodiment of the present disclosure provides a wafer structure, such as Figure 1 As shown, combined Figure 2 and Figure 3 The wafer structure includes: a substrate 100 , a selective transmission film layer 210 , a dissociation film layer 220 , a bonding film layer 230 and a wafer 300 .
[0053] The selective transmission film layer 210 is located on the substrate 100; the dissociation film layer 220 is located on the side of the selective transmission film layer 210 away from the substrate 100; the bonding film layer 230 is located on the side of the dissociation film layer 220 away from the substrate 100; the wafer 300 is bonded to the bonding film layer 230; the selective transmission film layer 210 is used to block the first ray X and transmit the second ray Y, and the wavelength band of the first ray X and the wavelength band of the second ray Y do not overlap; the selective transmission film layer 210 blocks the first ray X from irradiating from the wafer 300 to the substrate 100; the second ray Y passes through the selective transmission film layer 210 from the substrate 100 to irradiate the dissociation film layer 220.
[0054] The wafer structure provided by the present disclosure forms a selective transmission film layer 210 on the substrate 100, which can protect the substrate 100 from damage at least when the wafer 300 is cut, thereby improving the reuse rate of the substrate 100; in addition, the selective transmission film layer 210 can also transmit the second ray Y used for dissociation, which can achieve effective separation of the wafer 300 and the substrate 100 while ensuring the integrity of the substrate 100.
[0055] The following is a detailed description of the various parts of the wafer structure provided by the embodiment of the present disclosure with reference to the accompanying drawings:
[0056] In the embodiments provided in the present disclosure, Figure 1 As shown, combined Figures 2 to 11 , the substrate 100 is a carrier of the wafer 300 and can provide support for the wafer 300. Among them, the substrate 100 can be a glass carrier, a silicon carrier, a ceramic carrier or a metal carrier, among which the glass carrier can be borosilicate glass, quartz glass, etc.; the ceramic carrier can be aluminum oxide (Al2O3), aluminum nitride (AlN), etc.; the metal carrier can be stainless steel, titanium, etc. The substrate 100 provided in the present disclosure can be selected according to the materials of other film layers formed between the substrate 100 and the wafer 300, so as to facilitate subsequent cutting and dissociation processes. In the embodiment provided in the present disclosure, the substrate 100 is taken as a glass carrier as an example. For other types of substrates 100, the embodiments of the present disclosure can be adaptively modified, all within the scope of protection of the present disclosure.
[0057] In the embodiments provided in the present disclosure, Figure 1 As shown, the wafer structure includes a selective transmission film layer 210, a dissociation film layer 220, and a bonding film layer 230. The selective transmission film layer 210 is located on the substrate 100, the dissociation film layer 220 is located on the side of the selective transmission film layer 210 away from the substrate 100, and the bonding film layer 230 is located on the side of the dissociation film layer 220 away from the substrate 100. The wafer 300 is bonded to the bonding film layer 230.
[0058] Among them, multiple chips are formed on the wafer 300, and the multiple chips can be arranged in an array on the wafer 300. The chips can be separated by cutting lines. The cutting lines can be blank areas on the wafer 300, which are used for physical cutting after the chip manufacturing is completed to divide the wafer 300 into individual chips.
[0059] Among them, the wafer 300 is bonded to the substrate 100 through the bonding film layer 230, wherein the bonding film layer 230 can be a single film layer structure, by forming the bonding film layer 230 on the side of the dissociation film layer 220 away from the substrate 100, and then bonding the wafer 300 on the bonding film layer 230 to achieve the connection between the wafer 300 and the substrate 100; or the bonding film layer 230 can also be a double-layer structure, in which one bonding film layer 230 is grown on the side of the dissociation film layer 220 away from the substrate 100, and the other bonding film layer 230 is grown on the surface of the wafer 300, and the connection between the wafer 300 and the substrate 100 is achieved through the melt bonding between the two bonding film layers 230; of course, the bonding film layer 230 can also be a three-layer structure or even more film layer structure, which can be selected according to actual bonding requirements. Furthermore, in order to improve the alignment accuracy between the wafer 300 and the substrate 100 , the bonding film layer 230 generally adopts a double-layer structure.
[0060] In addition, when the bonding film layer 230 has a structure of two or more layers, the materials of each layer in the bonding film layer 230 can be the same or different. Furthermore, in order to improve the effectiveness of bonding, each film layer in the bonding film layer 230 is usually made of the same material.
[0061] The bonding film layer 230 can be formed of materials such as silicon oxide (SiO2), and can be formed by one or more methods such as physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), thermal oxidation (Thermal Oxidation), and sol-gel (Sol-Gel). The specific formation process can be selected according to parameters such as the specific material, thickness, and number of layers of the bonding film layer 230.
[0062] The thickness of the bonding film layer 230 can be 200nm to 500nm, and its specific thickness can be adjusted according to the different materials. In addition, when the bonding film layer 230 has a multi-layer structure, the thickness of the multi-layer bonding film layer 230 can be the same or different. In some specific embodiments, when the bonding film layer 230 is two layers, both layers can be made of silicon oxide of the same thickness to improve the uniformity of the bonding force, thereby improving the bonding quality, and also improving the alignment accuracy of the wafer 300 and the substrate 100, thereby improving the subsequent cutting accuracy of the wafer 300.
[0063] A dissociation film layer 220 is provided on the side of the bonding film layer 230 facing away from the wafer 300 . The dissociation film layer 220 is used to separate the wafer 300 from the substrate 100 through a dissociation process after the wafer 300 is cut.
[0064] The dissociation film layer 220 can be made of materials such as titanium nitride (TiN) and tantalum nitride (TaN). It can be formed by one or more of magnetron sputtering, arc ion plating, chemical vapor deposition (CVD), atomic layer deposition (ALD), sol-gel method (Sol-Gel), etc. The specific formation process can be selected according to the specific material, thickness and number of layers of the dissociation film layer 220.
[0065] It should be noted that the second ray Y is used to decompose the dissociation film layer 220 . When the dissociation film layer 220 is made of different materials, the type or wavelength of the second ray Y needs to be adaptively adjusted so that the second ray Y can dissociate the dissociation film layer 220 .
[0066] The dissociation film layer 220 can be dissociated by the irradiation of the second ray Y to achieve separation of the wafer 300 (chip) after cutting. When the first ray X is incident on the dissociation film layer 220, the dissociation film layer 220 can weaken and block part of the energy of the first ray X to achieve the purpose of preliminary protection of the substrate 100.
[0067] A selective transmission film layer 210 is provided on the substrate 100 . The selective transmission film layer 210 is used to block the first ray X and transmit the second ray Y. The wavelength bands of the first ray X and the second ray Y do not overlap.
[0068] Among them, Figure 2 、 Figure 5 and Figure 9As shown, the first ray X is incident from the side of the wafer 300 and is used to cut the wafer 300. For example, the first ray X can be ultraviolet light with a wavelength of 200 nm to 550 nm. The first ray X can effectively cut the wafer 300. Specifically, the first ray X can be ultraviolet light with a wavelength of 355 nm.
[0069] like Figure 3 、 Figure 6 and Figure 10 As shown, the second ray Y is incident from the substrate 100 side and is used to decompose the dissociation film layer 220. For example, the second ray Y can be infrared rays with a wavelength of 1500 nm to 2500 nm. The second ray Y can effectively dissociate the dissociation film layer 220, thereby separating the cut wafer 300 from the substrate 100. Specifically, the second ray Y can be an infrared ray with a wavelength of 2000 nm.
[0070] The wavelengths (wavebands) of the first ray X and the second ray Y do not overlap. The above embodiment uses ultraviolet light as the first ray X and infrared light as the second ray Y. However, in the rays used for wafer structures provided in the present disclosure, the first ray X can also be rays other than ultraviolet light, such as green lasers, and the second ray Y can also be rays other than infrared light, such as X-rays. Of course, to ensure that there is no interference between the dicing of the wafer 300 and the dissociation of the dissociation film layer 220, it is necessary to ensure that the wavelengths (wavebands) of the first ray X and the second ray Y do not overlap.
[0071] The selectively transparent film layer 210 blocks the first radiation X from irradiating the wafer 300 onto the substrate 100, thereby protecting the substrate 100 from damage by the first radiation X during dicing of the wafer 300. The selectively transparent film layer 210 transmits the second radiation Y, allowing the second radiation Y to irradiate the dissociation film layer 220. During the dissociation process, the wafer 300 and the substrate 100 are effectively separated without damaging the substrate 100. After the dissociation process, the selectively transparent film layer 210 can be removed to achieve the purpose of reusing the substrate 100.
[0072] The selective transmission film layer 210 may be composed of one or more materials selected from aluminum oxide (Al2O3), aluminum oxynitride (AlON), gallium nitride (GaN), gallium oxide (Ga2O3), or zirconium oxide (ZrO2). The thickness of the selective transmission film layer 210 may be 50 nm to 150 nm. For example, the thickness of the selective transmission film layer 210 may be 50 nm, 70 nm, 90 nm, 110 nm, 130 nm, or 150 nm. The thickness of the selective transmission film layer 210 may be selected based on the specific material type to protect the substrate 100, block the first radiation X, and transmit the second radiation Y.
[0073] It should be noted that due to differences in actual processes, the thickness of some parts of the selectively transparent film layer 210 may be uneven. Therefore, the thickness of the selectively transparent film layer 210 may refer to the average thickness of the selectively transparent film layer 210. Similarly, the thickness of other film layers in the present disclosure may also refer to the average thickness of the film layers, which will not be repeated in the following embodiments.
[0074] The selectively transmissive film layer 210 can be formed by one or more processes such as atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), and sputtering. The specific formation process can be selected and adaptively adjusted according to the selected material, thickness and other parameters, and this disclosure does not make specific limitations.
[0075] In some embodiments, as Figure 1 As shown, combined Figure 2 and Figure 3 The selective transmission film layer 210 and the dissociation film layer 220 are laminated together on the side facing the substrate 100. When a first ray X is incident from the side of the wafer 300, the first ray X passes through the bonding film layer 230 and the dissociation film layer 220 before entering the selective transmission film layer 210. The selective transmission film layer 210 blocks the first ray X, thereby protecting the substrate 100. Furthermore, because the selective transmission film layer 210 and the dissociation film layer 220 are laminated together, the selective transmission film layer 210 blocks the first ray X after it exits the dissociation film layer 220, preventing the first ray X from escaping to the substrate 100. This improves the protection of the substrate 100 and other film layers located between the selective transmission film layer 210 and the substrate 100.
[0076] In some embodiments, as Figure 4 As shown, combined Figure 5 and Figure 6 A protective film layer 240 is further disposed between the selective transmission film layer 210 and the dissociation film layer 220 to further protect the substrate 100. The protective film layer 240 is disposed on the side of the selective transmission film layer 210 facing away from the substrate 100. The protective film layer 240 provides a certain degree of protection for the selective transmission film layer 210 to ensure the functionality of the selective transmission film layer 210. The protective film layer 240 also regulates stress within the wafer structure to ensure the flatness of the wafer structure and improve the accuracy of subsequent wafer 300 dicing.
[0077] Among them, the protective film layer 240 can be formed of materials such as silicon oxide (SiO2), which can be formed by one or more methods such as physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), thermal oxidation (Thermal Oxidation), sol-gel (Sol-Gel), etc. The thickness of the protective film layer 240 can be 5nm to 100nm. The thickness and preparation process of the protective film layer 240 can be selected according to the material used for the protective film layer 240, and the present disclosure does not make specific restrictions. Furthermore, considering the bonding properties of the protective film layer 240 with the dissociation film layer 220 and the selective transmission film layer 210 and the economic efficiency of the protective film layer 240, the protective film layer 240 can usually be made of silicon oxide.
[0078] In some embodiments, as Figure 7 and Figure 8 As shown, combined Figure 9 and Figure 10 The selective transmission film layer 210 is also disposed on the side of the protective film layer 240 that is closer to the substrate 100. That is, the selective transmission film layer 210 is disposed on both the upper and lower surfaces of the protective film layer 240. The selective transmission film layer 210 includes a first sub-transmitting film layer 211 and a second sub-transmitting film layer 212. The first sub-transmitting film layer 211 is located on the side of the protective film layer 240 that is farther from the substrate 100, and the second sub-transmitting film layer 212 is located on the side of the protective film layer 240 that is closer to the substrate 100. Therefore, when a first ray X is incident, the first sub-transmitting film layer 211 blocks a portion of the first ray X, while the second sub-transmitting film layer 212 blocks the remaining first ray X. This prevents the first ray X from escaping and damaging the substrate 100. The first sub-transmitting film layer 211 and the second sub-transmitting film layer 212 provide dual protection for the substrate 100.
[0079] The thickness of the first sub-transmissive film layer 211 may be greater than or equal to the thickness of the second sub-transmissive film layer 212, so as to form a double or progressive protection effect on the substrate 100. In some specific embodiments, such as Figure 8 As shown, the thickness of the first sub-transmissive film layer 211 can be equal to the thickness of the second sub-transmissive film layer 212, so as to form a double protection effect on the substrate 100. In some specific embodiments, such as Figure 7 As shown, the thickness of the first sub-transmissive film layer 211 can be greater than the thickness of the second sub-transmissive film layer 212 to form a progressive protection effect on the substrate 100. In addition, this progressive protection effect can also improve economic efficiency and reduce the thickness of the wafer structure to meet the needs of device size miniaturization.
[0080] The shielding rate of the first sub-transmissive film layer 211 for the first ray X is greater than or equal to the shielding rate of the second sub-transmissive film layer 212 for the first ray X. In some specific embodiments, the shielding rate of the first sub-transmissive film layer 211 for the first ray X may be equal to the shielding rate of the second sub-transmissive film layer 212 for the first ray X, thereby achieving a double blocking effect on the first ray X and protecting the substrate 100. In some specific embodiments, the shielding rate of the first sub-transmissive film layer 211 for the first ray X may be greater than the shielding rate of the second sub-transmissive film layer 212 for the first ray X. The first sub-transmissive film layer 211 blocks most of the first ray X, and the second sub-transmissive film layer 212 blocks the remaining small portion of the first ray X, thereby preventing the first ray X from escaping and causing damage to the substrate 100. The first sub-transmissive film layer 211 and the second sub-transmissive film layer 212 provide dual protection for the substrate 100. In addition, the first sub-transmissive film layer 211 can also protect the film layers located between the first sub-transmissive film layer 211 and the substrate 100, especially the film layers located between the second sub-transmissive film layer 212 and the substrate 100, so that the film layers located at this position can be reused, reducing the production process and improving efficiency.
[0081] In this disclosure, transmittance is a physical quantity that describes the ability of rays to penetrate a film layer; shielding rate refers to the ability of a film layer to block or weaken the energy of incident rays, which is a complementary concept to transmittance.
[0082] The transmittance of the second sub-transmissive film layer 212 to the second ray Y is greater than or equal to the transmittance of the first sub-transmissive film layer 211 to the second ray Y, thereby ensuring that the energy transmitted by the second ray Y can effectively dissociate the dissociation film layer 220. In some specific embodiments, the transmittance of the second sub-transmissive film layer 212 to the second ray Y can be equal to the transmittance of the first sub-transmissive film layer 211 to the second ray Y. The transmittance of the first sub-transmissive film layer 211 and the second sub-transmissive film layer 212 to the second ray Y is sufficient to ensure the dissociation of the dissociation film layer 220, thereby ensuring effective separation of the wafer 300 from the substrate 100. In some specific embodiments, the transmittance of the second sub-transmissive film layer 212 to the second ray Y can be greater than the transmittance of the first sub-transmissive film layer 211 to the second ray Y. When the second ray Y is incident through the side of the substrate 100, the second sub-transmissive film layer 212 can transmit most of the second ray Y, thereby reducing the shielding effect of the second sub-transmissive film layer 212 on the second ray Y, improving the transmittance of the second ray Y, and ensuring that the second ray Y still has sufficient energy to decompose the dissociation film layer 220 after passing through the first sub-transmissive film layer 211 and the second sub-transmissive film layer 212.
[0083] It should be noted that the thickness relationship between the first sub-transmitting film layer 211 and the second sub-transmitting film layer 212 provided in the above embodiments of the present disclosure, the shielding rate relationship for the first ray X, and the transmittance relationship for the second ray Y can form a variety of combinations, all of which are within the scope of protection of the present disclosure. Various combinations will not be listed one by one here.
[0084] In some embodiments, as Figure 1 As shown, in order to avoid warping after multiple film layers are formed on the substrate 100, which affects the accuracy of subsequent wafer 300 cutting, a stress adjustment film layer 260 can also be set on the surface of the substrate 100. The stress adjustment film layer 260 can provide compressive stress or tensile stress for the wafer structure to improve the flatness of the wafer structure, thereby improving the accuracy of subsequent wafer 300 cutting or reassembly.
[0085] The stress adjustment film layer 260 can be formed of materials such as silicon oxide (SiO2) and silicon nitride (Si3N4), and can be formed by one or more methods such as physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), thermal oxidation (Thermal Oxidation), and sol-gel (Sol-Gel). The thickness of the stress adjustment film layer 260 can be 5nm to 20nm, and it can be formed on the substrate 100 in one or more layers. Taking the number of layers of the stress adjustment film layer 260 as an example, the thickness of the stress adjustment film layer 260 needs to meet the purpose of adjusting the pressure of the wafer structure to achieve the purpose of improving the flatness of the wafer structure, but the thickness of the film layer should not be too large to meet the needs of device miniaturization. The number of layers, thickness, material and preparation process of the stress adjustment film layer 260 can be selected or adaptively adjusted according to parameters such as the thickness of the substrate 100 and other film layers in the wafer structure, and this disclosure does not make specific limitations.
[0086] In some embodiments, as Figure 1 As shown, in order to provide support for the wafer 300 and further protect the substrate 100, a reconstruction film layer 250 can be provided on the side of the stress adjustment film layer 260 away from the substrate 100. The reconstruction film layer 250 can have both high-temperature process compatibility and high chemical protection capabilities. When the wafer 300 is reconstructed, local stress concentration can be prevented, thereby improving the reliability of the wafer 300 reconstruction and the accuracy of the wafer 300 cutting.
[0087] In some embodiments, when the stress adjustment film layer 260 is not provided in the wafer structure, the reconstruction film layer 250 can be directly disposed on the surface of the substrate 100 .
[0088] The reconstructed film layer 250 can be made of a material such as silicon carbonitride (SiCN), and can be formed by one or more methods such as plasma-enhanced chemical vapor deposition (PECVD), low-pressure chemical vapor deposition (LPCVD), atomic layer deposition (ALD), physical vapor deposition (PVD), or sol-gel. The thickness of the reconstructed film layer 250 can be 5nm to 10nm, and it can be formed on the stress adjustment film layer 260 or the substrate 100 in one or more layers. Taking the case where the reconstructed film layer 250 has one layer as an example, the thickness of the reconstructed film layer 250 needs to meet the purpose of mechanically supporting the wafer structure and protecting the substrate 100, but the thickness of the film layer should not be too large to meet the requirements of device miniaturization. The number of layers, thickness, material and preparation process of the reconstructed film layer 250 can be selected or adaptively adjusted according to parameters such as the thickness of the substrate 100 and other film layers in the wafer structure, and this disclosure does not make specific limitations.
[0089] In some embodiments, as Figure 11 As shown, in order to make the reconstructed film layer 250 reusable, the selectively transparent film layer 210 can be set on the side of the reconstructed film layer 250 away from the substrate 100. By selecting the blocking effect of the transparent film layer 210 on the first ray X, it is ensured that the reconstructed film layer 250 is not damaged when the first ray X cuts the wafer 300. After the wafer 300 is subsequently separated from the substrate 100, both the substrate 100 and the reconstructed film layer 250 can be reused, thereby reducing the film production process and improving economy.
[0090] In the present disclosure, the remaining film layers on the substrate 100 can be removed by using one or more combinations of methods such as chemical mechanical polishing (CMP), wet etching, and dry etching to remove the film layers located on the substrate 100, retain the substrate 100, and reuse the substrate 100.
[0091] The wafer structure provided by the present disclosure, by providing a selective transmission film layer 210 between the substrate 100 and the dissociation film layer 220, can, on the one hand, ensure that the second ray Y is transmitted from the substrate 100 side to the dissociation film layer 220, thereby achieving effective separation of the wafer 300 and the substrate 100; on the other hand, it can block the first ray X from being incident on the substrate 100 from the wafer 300 side, thereby protecting the substrate 100 when the wafer 300 is cut, improving the reuse rate of the substrate 100, and thus improving economic efficiency.
[0092] The present disclosure provides a method for cutting a wafer structure. Figure 12 As shown, the method includes: steps S1 to S5.
[0093] Wherein, step S1, providing a substrate;
[0094] Step S2: forming a laminated structure on a substrate, the laminated structure comprising at least a selective transmission film layer, a dissociation film layer, and a bonding film layer sequentially formed in a direction perpendicular to the surface of the substrate; wherein the selective transmission layer is configured to block the first ray and transmit the second ray, and the wavelength band of the first ray does not overlap with the wavelength band of the second ray;
[0095] Step S3, bonding a wafer on the bonding film layer;
[0096] Step S4, cutting the wafer using the first ray;
[0097] Step S5: utilizing the second ray to pass through the selective transmission film layer from the substrate to dissociate the dissociation film layer.
[0098] The present disclosure provides a method for cutting a wafer structure. In this method, when a first ray is used to cut the wafer, a selective transmission film layer can block the first ray from being incident on a substrate, thereby protecting the substrate from damage by the first ray. At the same time, when a second ray passes through the selective transmission film layer from the substrate to dissociate the dissociation film layer, the selective transmission film layer can ensure the transmittance of the second ray, thereby ensuring the dissociation effectiveness of the dissociation film layer.
[0099] In the embodiment provided in the present disclosure, after step S5, the method further includes: removing the selective transmission film layer located on the substrate and each film layer located on the side of the selective transmission film layer away from the substrate, retaining the substrate; and reforming the stacked structure on the substrate to cut the wafer structure.
[0100] The arrangement of each film layer in the wafer structure in the cutting method provided by the present disclosure is as shown in the embodiment of the wafer structure above, and will not be repeated here.
[0101] In a specific embodiment, referring to Figures 4 to 6 , the cutting method may include:
[0102] Providing a substrate 100;
[0103] A stress adjustment film layer 260 , a reconstitution film layer 250 , a selective transmission film layer 210 , a protective film layer 240 , a dissociation film layer 220 and a bonding film layer 230 are sequentially formed on the surface of the substrate 100 ;
[0104] performing a planarization process on the bonding film layer 230;
[0105] Bonding the wafer 300 on the bonding film layer 230 by a fusion bonding process;
[0106] A first ray X (355 nm ultraviolet laser) is irradiated from the side of the wafer 300 into the wafer 300 to cut the wafer 300 along the cutting streets;
[0107] A second ray Y (2000 nm infrared laser) is used to irradiate the dissociation film layer 220 from the substrate 100 side to dissociate the dissociation film layer 220, thereby separating the wafer 300 from the substrate 100;
[0108] The selective transmission film layer 210 and the layers above it on the substrate 100 are removed, and the substrate 100 and the reconstructed film layer 250 are retained. The substrate 100 and the reconstructed film layer 250 are reused during the next cutting.
[0109] In a specific embodiment, referring to Figures 8 to 10 , the cutting method may include:
[0110] Providing a substrate 100;
[0111] A stress adjustment film layer 260 , a reconstitution film layer 250 , a first sub-transmissive film layer 211 , a protective film layer 240 , a second sub-transmissive film layer 212 , a dissociation film layer 220 and a bonding film layer 230 are sequentially formed on the surface of the substrate 100 ;
[0112] performing a planarization process on the bonding film layer 230;
[0113] Bonding the wafer 300 on the bonding film layer 230 by a fusion bonding process;
[0114] A first ray X (355 nm ultraviolet laser) is irradiated from the side of the wafer 300 into the wafer 300 to cut the wafer 300 along the cutting streets;
[0115] A second ray Y (2000 nm infrared laser) is used to irradiate the dissociation film layer 220 from the substrate 100 side to dissociate the dissociation film layer 220, thereby separating the wafer 300 from the substrate 100;
[0116] The second sub-transmissive film layer 212 and the above film layers on the substrate 100 are removed, and the substrate 100 and the reconstructed film layer 250 are retained. The substrate 100 and the reconstructed film layer 250 are reused during the next cutting.
[0117] Experiments have shown that the cost of the substrate 100 (carrier) accounts for 15% to 20% of the total cost of advanced packaging. The substrate 100 in the cutting method provided by the present disclosure can be reused, which can reduce material costs by at least 30%, greatly improving economic efficiency.
[0118] It should be noted that although the steps of the wafer structure cutting method disclosed herein are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in this specific order, or that all steps shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.
[0119] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.
Claims
1. A wafer structure, characterized in that: include: substrate; Selecting a transmissive film layer, located on the substrate; a dissociation film layer, located on a side of the selective transmission film layer away from the substrate; a bonding film layer, located on a side of the dissociation film layer away from the substrate; a wafer bonded on the bonding film layer; The selective transmission film layer is used to block the first ray and transmit the second ray, and the wavelength band of the first ray does not overlap with the wavelength band of the second ray; The selective transmission film layer blocks the first ray from being irradiated from the wafer to the substrate; the second ray is irradiated from the substrate to the dissociation film layer through the selective transmission film layer.
2. The wafer structure according to claim 1, wherein: The selective transmission film layer is laminated to the dissociation film layer.
3. The wafer structure according to claim 1, wherein: It also includes a protective film layer, which is arranged between the selective transmission film layer and the dissociation film layer.
4. The wafer structure according to claim 3, characterized in that: The selective transmission film layer is also arranged on a side of the protective film layer close to the substrate.
5. The wafer structure according to claim 4, characterized in that: The selectively transmissive film layer includes a first sub-transmissive film layer and a second sub-transmissive film layer, wherein the first sub-transmissive film layer is located on a side of the protective film layer away from the substrate, and the second sub-transmissive film layer is located on a side of the protective film layer close to the substrate; The thickness of the first sub-transmissive film layer is greater than or equal to the thickness of the second sub-transmissive film layer.
6. The wafer structure according to claim 5, characterized in that: The shielding rate of the first sub-transmissive film layer to the first ray is greater than or equal to the shielding rate of the second sub-transmissive film layer to the first ray.
7. The wafer structure according to claim 5, characterized in that: The transmittance of the second sub-transmissive film layer to the second ray is greater than or equal to the transmittance of the first sub-transmissive film layer to the second ray.
8. The wafer structure according to any one of claims 1 to 7, characterized in that: The system further comprises a reconstruction film layer, wherein the reconstruction film layer is located between the substrate and the selective transmission film layer.
9. The wafer structure according to claim 8, characterized in that: The invention also includes a stress adjustment film layer, wherein the stress adjustment film layer is located between the substrate and the reconstruction film layer.
10. A method for cutting a wafer structure, characterized in that: include: S1. Provide a substrate; S2. Forming a stacked structure on the substrate, the stacked structure comprising at least a selective transmission film layer, a dissociation film layer, and a bonding film layer sequentially formed in a direction perpendicular to the surface of the substrate; wherein the selective transmission film layer is configured to block a first ray and transmit a second ray, and the wavelength band of the first ray does not overlap with the wavelength band of the second ray; S3, bonding a wafer on the bonding film layer; S4, cutting the wafer using the first ray; S5. Utilize the second ray to transmit the selective transmission film layer from the substrate to dissociate the dissociation film layer.