Method for manufacturing semiconductor device and semiconductor device

Abstract

In this method for manufacturing a semiconductor device, first, a substrate 10A having a support substrate 11A, and a conductive part 12A and a polyimide film 13A provided on the support substrate 11A is prepared. Thereafter, a surface-side part 132 of the polyimide film 13A is cut by a fly-cutting method. In the method for manufacturing a semiconductor device, the tensile elastic modulus of an organic insulating material constituting the polyimide film 13A is 3.5 GPa or less. By using the organic insulating material having such a tensile elastic modulus, the wear of the device used for the fly-cutting method is suppressed, and the surface roughness of the substrate 10A can be reduced. The substrate 10A with the abovementioned features can be used, for example, for hybrid bonding.

Description

Semiconductor device manufacturing method and semiconductor device

[0001] The present disclosure relates to a method for manufacturing a semiconductor device and a semiconductor device.

[0002] In recent years, three-dimensional packaging has been considered to improve the integration density of LSIs. Non-Patent Document 1 discloses an example of three-dimensional packaging of semiconductor chips.

[0003] FC Chen et al., “System on Integrated Chips(SoIC TM) for 3D Heterogeneous Integration”, 2019 IEEE 69th Electronic Components and Technology Conference (ECTC), p.594-599(2019)

[0004] When manufacturing semiconductor devices using three-dimensional packaging, hybrid bonding technology, which directly bonds two devices, has been considered in order to miniaturize the wiring between the devices. However, if the device substrate surface is rough, poor bonding may occur during hybrid bonding. Specifically, the greater the substrate surface roughness, the lower the bonding strength between the devices. Therefore, a semiconductor device manufacturing method that can reduce the substrate surface roughness is desired.

[0005] An object of the present disclosure is to provide a method for manufacturing a semiconductor device that can reduce surface roughness.

[0006] The present inventors have conducted research into a method for manufacturing a semiconductor device that can reduce the surface roughness of a substrate, and as a result, have obtained the following findings, which have led to the present invention.

[0007] When cutting by flycutting, the degree of wear of the equipment used in the flycutting method affects the surface roughness of the substrate after cutting. For example, if flycutting is performed when the equipment is worn, the surface roughness of the substrate after cutting tends to increase. Therefore, in order to reduce the surface roughness of the substrate after cutting, it is desirable to reduce the wear of the equipment used in the flycutting method. Therefore, the inventors focused on the tensile modulus of the organic insulating material contained in the insulating film of the substrate and found that when the tensile modulus of the organic insulating material is 3.5 GPa or less, the wear of the equipment used in the flycutting method is suppressed. That is, the inventors found that a manufacturing method of a semiconductor device in which the tensile modulus of the organic insulating material contained in the insulating film of the substrate is 3.5 GPa or less can reduce the surface roughness of the substrate. Such a relationship between the tensile modulus of the organic insulating material contained in the insulating film of the substrate, the wear of the equipment used in the flycutting method, and the surface roughness of the substrate has not been considered in the past.

[0008] [1] One aspect of the present disclosure relates to a method for manufacturing a semiconductor device, the method comprising the steps of: preparing a first substrate having a first support substrate and a first insulating film provided on the first support substrate and including an organic insulating material; and cutting at least a portion of the first insulating film by a fly-cutting method, wherein the organic insulating material has a tensile modulus of elasticity of 3.5 GPa or less.

[0009] In this manufacturing method, the tensile modulus of the organic insulating material contained in the first insulating film is 3.5 GPa or less. In this case, as described above, wear of the equipment used in the fly-cutting method is suppressed. Therefore, according to the manufacturing method of the semiconductor device described in [1] above, the surface roughness of the substrate can be reduced.

[0010] [2] The semiconductor device manufacturing method of [1] above may further include a step of polishing the surface of the first insulating film. The polishing step may be performed after the cutting step. As described above, the greater the surface roughness of the substrate, the lower the bonding strength between devices (substrates). Here, in order to planarize the substrate surface and reduce the surface roughness, methods of polishing the substrate surface have been considered in addition to the cutting by the fly-cut method described above. However, if only the substrate surface is polished, the surface roughness can be further reduced, but the polishing operation may require a long time. In the semiconductor device manufacturing method of [2] above, part of the polishing step can be replaced by the cutting step. This makes it possible to reduce the surface roughness while shortening the processing time in the polishing step. Therefore, the semiconductor device manufacturing method of [2] above can easily reduce surface roughness.

[0011] [3] In the method for manufacturing a semiconductor device according to the above [2], the polishing step may include polishing the surface of the cut first insulating film by a CMP method. According to the method for manufacturing a semiconductor device according to the above [3], the polishing step can be easily performed. Furthermore, the surface roughness of the first insulating film can be more reliably reduced.

[0012] [4] In the method for manufacturing a semiconductor device according to any one of [1] to [3] above, the first substrate may further include a first conductive portion provided on a first support substrate. In the cutting step, at least a portion of the first insulating film may be cut by a fly-cutting method without cutting the first conductive portion. According to the method for manufacturing a semiconductor device according to [4] above, even when the first substrate includes the first conductive portion, the surface roughness of the substrate can be reduced for the reasons described above.

[0013] [5] The method for manufacturing a semiconductor device according to [1] above may further include the steps of preparing a second substrate having a second support substrate and a second insulating film provided on the second support substrate, and bonding the first insulating film to the second insulating film. In this case, for the reasons described above, the first substrate and the second substrate are bonded together while the surface roughness of the first substrate is reduced. Therefore, according to the method for manufacturing a semiconductor device according to [5] above, the bonding strength between the first substrate and the second substrate can be improved.

[0014] [6] In the method for manufacturing a semiconductor device according to [5] above, the first substrate may further include a first conductive portion provided on the first support substrate, and the second substrate may further include a second conductive portion provided on the second support substrate. In the bonding step, the first conductive portion and the second conductive portion may further be bonded. In this case, for the reasons described above, the first substrate and the second substrate are bonded while the surface roughness of the first substrate is reduced. Therefore, according to the method for manufacturing a semiconductor device according to [6] above, even when the first substrate includes the first conductive portion and the second substrate includes the second conductive portion, the bonding strength between the first substrate and the second substrate can be improved.

[0015] [7] In the semiconductor device manufacturing method according to any one of [1] to [6] above, the tensile modulus of the organic insulating material may be 3.0 GPa or less. In this case, wear of the equipment used in the flycutting method is further suppressed. Therefore, according to the semiconductor device manufacturing method according to [7] above, the surface roughness of the substrate can be further reduced.

[0016] [8] In the method for manufacturing a semiconductor device according to any one of [1] to [7] above, the organic insulating material may be polyimide. According to the method for manufacturing a semiconductor device according to [8] above, it is possible to easily realize a first insulating film in which the organic insulating material has a tensile modulus of elasticity of 3.5 GPa or less.

[0017] [9] Another aspect of the present disclosure relates to a semiconductor device. The semiconductor device includes a first substrate having a first support substrate and a first insulating film provided on the first support substrate and including an organic insulating material, and a second substrate having a second support substrate and a second insulating film provided on the second support substrate. An electrode is formed by bonding the first insulating film and the second insulating film. The tensile modulus of the organic insulating material is 3.5 GPa or less.

[0018]

[10] In the semiconductor device of [9] above, the first substrate may further include a first conductive portion provided on the first support substrate. The second substrate may further include a second conductive portion provided on the second support substrate. The semiconductor device may include an electrode formed by joining the first conductive portion and the second conductive portion.

[0019]

[11] In the semiconductor device of [9] or

[10] above, the organic insulating material may have a tensile modulus of elasticity of 3.0 GPa or less.

[0020]

[12] In the semiconductor device according to any one of the above [9] to

[11] , the organic insulating material may contain polyimide.

[0021]

[13] In the semiconductor device according to any one of [9] to

[12] above, the second insulating film may contain an organic insulating material, and the tensile modulus of elasticity of the organic insulating material of the second insulating film may be 3.5 GPa or less.

[0022] FIG. 1 illustrates an example of a semiconductor device according to a first embodiment of the present disclosure. FIG. 2 is a cross-sectional view for explaining a method for manufacturing the semiconductor device shown in FIG. 1 , illustrating an example of a step of preparing a first substrate. FIG. 3 is a cross-sectional view for explaining a method for manufacturing the semiconductor device shown in FIG. 1 , illustrating an example of a step of cutting a first insulating film by a flycutting method. FIG. 4 is a cross-sectional view for explaining a method for manufacturing the semiconductor device shown in FIG. 1 , illustrating an example of a step of polishing the surface of the cut first insulating film. FIG. 5 is a cross-sectional view for explaining a method for manufacturing the semiconductor device shown in FIG. 1 , illustrating an example of a step of bonding the first insulating film and a second insulating film. FIG. 6 illustrates an example of a semiconductor device according to a second embodiment of the present disclosure. FIG. 7 is a cross-sectional view for explaining a method for manufacturing the semiconductor device shown in FIG. 6 , illustrating an example of a step of preparing a first substrate. FIG. 8 is a cross-sectional view for explaining a method for manufacturing the semiconductor device shown in FIG. 6 , illustrating an example of a step of cutting a second portion of the first insulating film by a flycutting method. FIG. 9 is a cross-sectional view for explaining a method for manufacturing the semiconductor device shown in FIG. 6 , illustrating an example of a step of polishing the surface of the cut first insulating film. 10A to 10C are cross-sectional views for explaining a method for manufacturing the semiconductor device shown in FIG. 6, showing an example of a step of joining the first conductive portion and the second conductive portion.

[0023] Hereinafter, several embodiments of the present disclosure will be described in detail, with reference to the drawings as necessary. In the following description, identical or equivalent parts will be designated by the same reference numerals, and redundant explanations will be omitted. Furthermore, positional relationships such as up, down, left, right, etc. will be based on the positional relationships shown in the drawings unless otherwise specified. When terms such as "left," "right," "front," "back," "top," "bottom," "upper," and "lower" are used in the description and claims of this specification, these terms are intended for explanatory purposes and do not necessarily mean that these relative positions will always be the same. Furthermore, the dimensional ratios of the drawings are not limited to those shown. Furthermore, in this specification, the term "process" includes not only independent processes, but also processes that cannot be clearly distinguished from other processes as long as the intended effect of the process is achieved.

[0024] First Embodiment A semiconductor device and a method for manufacturing the semiconductor device according to a first embodiment of the present disclosure will be described with reference to FIGS.

[0025] (Configuration of Semiconductor Device) First, the configuration of a semiconductor device according to the first embodiment will be described with reference to FIG. 1 . FIG. 1 shows an example of a semiconductor device according to the first embodiment. As shown in FIG. 1 , the semiconductor device 1 is, for example, an example of a semiconductor package, and includes an insulating film 3, a first substrate 10, and a second substrate 20. The insulating film 3 is formed by bonding a first insulating film 13 of the first substrate 10 and a second insulating film 23 of the second substrate 20 (described later) together (see FIG. 5 ). Here, the tensile modulus of the organic insulating material contained in the first insulating film 13 that forms the insulating film 3 is 3.5 GPa or less, or may be 3.0 GPa or less, or may be 2.8 GPa or less. Furthermore, when the second insulating film 23 also contains an organic insulating material, the tensile modulus of the organic insulating material may be 3.5 GPa or less, or may be 3.0 GPa or less, or may be 2.8 GPa or less. The organic insulating material may include, for example, polyimide, a polyimide precursor, polyamideimide, benzocyclobutene (BCB), polybenzoxazole (PBO), or a PBO precursor.

[0026] In the semiconductor device 1, a first substrate 10 and a second substrate 20 are bonded together. The first substrate 10 may include a semiconductor element. The semiconductor element included in the first substrate 10 may be disposed on a surface opposite to the second substrate 20 when the first substrate 10 and the second substrate 20 are bonded together. The second substrate 20 may also include a semiconductor element. The semiconductor element included in the second substrate 20 may be disposed on a surface opposite to the first substrate 10 when the first substrate 10 and the second substrate 20 are bonded together. The semiconductor elements included in the first substrate 10 and the second substrate 20 are, for example, semiconductor chips such as LSI (Large Scale Integrated Circuit) chips, CMOS (Complementary Metal Oxide Semiconductor) sensors, and memories. The semiconductor elements included in the first substrate 10 and the second substrate 20 may be other types of semiconductor chips.

[0027] (Method of Manufacturing Semiconductor Device) Next, a method of manufacturing the semiconductor device 1 will be described with reference to FIGS. 2 to 5. FIG. 2 is a cross-sectional view for explaining the method of manufacturing the semiconductor device shown in FIG. 1, showing an example of a step of preparing a substrate. FIG. 3 is a cross-sectional view for explaining the method of manufacturing the semiconductor device shown in FIG. 1, showing an example of a step of cutting the first insulating film by a fly-cutting method. FIG. 4 is a cross-sectional view for explaining the method of manufacturing the semiconductor device shown in FIG. 1, showing an example of a step of polishing the surface of the cut first insulating film. FIG. 5 is a cross-sectional view for explaining the method of manufacturing the semiconductor device shown in FIG. 1, showing an example of a step of bonding the first insulating film and the second insulating film.

[0028] The semiconductor device 1 can be manufactured, for example, through the following steps (a) to (g). That is, the method for manufacturing the semiconductor device 1 includes the following steps (a) to (g): a) preparing a first substrate having a first support substrate and a first insulating film provided on the first support substrate and containing an organic insulating material; b) cutting at least a portion of the first insulating film by a flycutting method; c) polishing the surface of the first insulating film, which is a step performed after step (b); d) preparing a second substrate having a second support substrate and a second insulating film provided on the second support substrate and containing an organic insulating material; e) cutting at least a portion of the second insulating film by a flycutting method; f) polishing the surface of the second insulating film, which is a step performed after step (e); and g) bonding the first substrate and the second substrate, which is a step performed after steps (c) and (f).

[0029] The step g) of bonding the first substrate and the second substrate includes the following steps: g1) bonding the first insulating film and the second insulating film.

[0030] [Step (a)] Step (a) is a step of preparing a first substrate 10. To prepare the first substrate 10, first, a first support substrate 11 having a first insulating film 13 is prepared. For example, the first support substrate 11 is a silicon wafer. The first support substrate 11 is, for example, a silicon wafer having a thickness of 0.2 mm or more and 2.0 mm or less. The diameter of the first support substrate 11 is, for example, 200 mm, 300 mm, or 450 mm. Alternatively, the first support substrate 11 may be a substrate including a glass plate, a SUS plate, or a glass cloth plate, or may be a resin substrate that seals semiconductor elements. The first support substrate 11 may be a panel-shaped substrate. In this case, the first support substrate 11 is, for example, a rectangular panel with one side measuring 300 mm or more and 700 mm or less. The first support substrate 11 may have another configuration.

[0031] In the first substrate 10 prepared in step (a), the first insulating film 13 is provided on the first support substrate 11. The first insulating film 13 is made of an organic insulating material. The first insulating film 13 may be configured to partially contain the organic insulating material. The tensile modulus of the organic insulating material is 3.5 GPa or less, or may be 3.0 GPa or less, or may be 2.8 GPa or less. Such a first insulating film 13 is provided, for example, by applying a liquid organic insulating material onto the surface of the first support substrate 11 by spin coating.

[0032] The organic insulating material includes, for example, polyimide, a polyimide precursor, polyamideimide, benzocyclobutene (BCB), polybenzoxazole (PBO), or a PBO precursor.

[0033] The thickness of the first insulating film 13 formed on the first support substrate 11 is, for example, 10 μm or less, preferably 5 μm or less, and more preferably 3 μm or less. The thickness of the first insulating film 13 may be 1 μm or more. The first insulating film 13 may be made of an inorganic material.

[0034] After the first insulating film 13 is provided, the first insulating film 13 may be heat-cured. In this case, the heating temperature may be, for example, 100° C. or higher and 400° C. or lower, and the heating time may be, for example, 30 minutes or higher and 3 hours or lower.

[0035] By the above step (a), as shown in FIG. 2, a first substrate 10 having a first support substrate 11 and a first insulating film 13 provided on the first support substrate 11 is prepared.

[0036] [Step (b)] Step (b) is a step of cutting the first insulating film 13. In step (b), the first insulating film 13 is cut by a fly-cutting method. In one example, at least a portion (a portion on the surface side) of the first insulating film 13 is cut by the fly-cutting method.

[0037] In step (b) of this embodiment, as shown in FIG. 3 , the first insulating film 13 is cut by a flycutting method so that the surface of the first support substrate 11 is not exposed. That is, in step (b) of this embodiment, the thickness of the first insulating film 13 is thinned by the flycutting method. The thickness of the first insulating film 13 cut by the flycutting method is, for example, 2 μm or more and 20 μm or less before cutting. Therefore, at the time when step (b) of this embodiment is completed, the thickness of the first insulating film 13 is, for example, 1 μm or more and 10 μm or less.

[0038] In the fly-cutting method, a grinding device 100 using, for example, a diamond tool is used. In this case, as shown in FIG. 3 , the grinding device 100 is moved in a predetermined direction on the first substrate 10 to cut the first insulating film 13. A specific example of the grinding device 100 is an automatic surface planer (manufactured by Disco Corporation, product name "DAS8930") compatible with 300 mm wafers. The cutting of the first insulating film 13 by the fly-cutting method can also be considered a planarization process. In addition, in step (b), etching or the like may be combined with the fly-cutting method.

[0039] At the end of step (b) in this embodiment, the surface roughness of the first insulating film 13 cut by the flycutting method is, for example, 10 nm to 600 nm, and may be 200 nm to 600 nm. In this embodiment, the surface roughness is the arithmetic mean roughness (Ra) defined in JIS B 0601 2001. The surface roughness of the first insulating film 13 after cutting is measured, for example, by scanning a 100 μm × 100 μm area including the first insulating film 13 using a laser microscope (Olympus Corporation's "LEXT OLS3000"). In this embodiment, the first insulating film 13 is configured to contain an organic insulating material having a tensile modulus of elasticity of 3.5 GPa, preferably 3.0 GPa, thereby reducing the surface roughness of the portion cut by the flycutting method.

[0040] 4, in the step (c) of the present embodiment, the remaining portion of the cut first insulating film 13 is polished so as not to expose the surface of the first support substrate 11. More specifically, the thickness of the first insulating film 13 is further reduced by polishing the surface of the cut first insulating film 13. That is, in the step (c) of the present embodiment, the thickness of the first insulating film 13 is reduced by polishing.

[0041] The above-described polishing can be performed using a grinder for electronic materials processing or a chemical mechanical polishing (CMP) method. In step (c) of this embodiment, the surface of the first insulating film 13 is polished by the CMP method. The CMP method uses, for example, a polishing device 110. In this case, as shown in FIG. 4 , the polishing device 110 is pressed against the surface of the first insulating film 13 and rotated, thereby polishing the surface of the first insulating film 13 by mechanical friction between the polishing liquid applied to the surface of the polishing device 110 and the first insulating film 13. The above-described polishing of the surface of the first insulating film 13 by the CMP method can also be considered a planarization process.

[0042] At the time when step (c) in this embodiment is completed, the surface roughness of the first insulating film 13 becomes, for example, 0.1 nm or more and 5 nm or less due to the polishing described above. The surface roughness is the arithmetic mean roughness (Ra) defined in JIS B 0601 2001. The surface roughness of the first insulating film 13 after polishing is measured, for example, by the same method as that for the surface roughness of the first insulating film 13 after cutting.

[0043] [Step (d)] Step (d) is a step of preparing a second substrate 20 different from the first substrate 10. In step (d), the second substrate 20 is prepared, which includes a second support substrate 21 and a second insulating film 23 provided on the second support substrate 21. In the second substrate 20 prepared in step (d), the second insulating film 23 covers the surface of the second support substrate 21. Here, the second insulating film 23 may contain an organic insulating material or an inorganic insulating material. When the second insulating film 23 contains an organic insulating material, the organic insulating material may have a modulus of 3.5 GPa or less, 3.0 GPa or less, or 2.8 GPa or less. The method for preparing the second substrate 20 is similar to the method for preparing the first substrate 10, and therefore detailed description thereof will be omitted. However, the second substrate 20 is prepared through the above-described steps. The second substrate 20 does not need to have exactly the same configuration as the first substrate 10, and the thickness or material of the second support substrate 21, the thickness or material of the second insulating film 23, etc. may be different from those of the first substrate 10. Furthermore, the second substrate 20 may be in the form of a silicon wafer, or may be an individualized device.

[0044] [Step (e)] Step (e) is a step of cutting the second insulating film 23. The method of cutting the second insulating film 23 is similar to the method of cutting the first insulating film 13, and therefore detailed description will be omitted, but the second insulating film 23 is cut through the steps shown in Fig. 3. In step (e), the second insulating film 23 is cut by a fly-cutting method so as not to expose the surface of the second support substrate 21.

[0045] [Step (f)] Step (f) is a step of polishing the surface of the second insulating film 23, and is a step performed after step (e). The method of polishing the surface of the second insulating film 23 is similar to the method of polishing the surface of the first insulating film 13, and therefore detailed description will be omitted. However, the surface of the second insulating film 23 is polished through the steps shown in Fig. 4. In step (f), the remaining portion of the cut second insulating film 23 is polished so that the surface of the second support substrate 21 is not exposed.

[0046] [Step (g)] Step (g) is a step of bonding the first substrate 10 and the second substrate 20, and is performed after steps (c) and (f). In step (g), the first insulating film 13 of the first substrate 10 and the second insulating film 23 of the second substrate 20 are bonded together. Here, at least one of the first substrate 10 and the second substrate 20 is aligned so that the first insulating film 13 of the first substrate 10 and the second insulating film 23 of the second substrate 20 face each other. Both the first substrate 10 and the second substrate 20 may be aligned. For such alignment, an alignment mark or the like may be provided on at least one of the first substrate 10 and the second substrate 20.

[0047] When bonding the first substrate 10 and the second substrate 20, organic substances or metal oxides adhering to the surfaces of the first substrate 10 and the second substrate 20 are removed, and then the second substrate 20 is aligned with the first substrate 10. Once the alignment is complete, the first insulating film 13 and the second insulating film 23 are bonded together by hybrid bonding. At this time, the first insulating film 13 and the second insulating film 23 may be uniformly heated before bonding. By bonding the first insulating film 13 and the second insulating film 23, the insulating film 3 of the semiconductor device 1 is formed, as shown in FIG. 1 .

[0048] The temperature difference between the first substrate 10 and the second substrate 20 during bonding is preferably, for example, 10°C or less. By heat bonding at such a uniform temperature, the first insulating film 13 is mechanically and firmly attached to the second insulating film 23. Furthermore, because heat bonding is performed at a uniform temperature, positional deviation at the bonding location is unlikely to occur, allowing for highly accurate bonding. Note that the first substrate 10 and the second substrate 20 may be bonded by other bonding methods, such as room temperature bonding.

[0049] Through the above steps, the semiconductor device 1 shown in FIG. 1 is manufactured.

[0050] As described above, according to the manufacturing method of the semiconductor device 1 of this embodiment, in the first substrate 10 prepared in step (a), the tensile modulus of the organic insulating material contained in the first insulating film 13 is 3.5 GPa or less. In this case, wear of the grinding device 100 used in the flycutting method is suppressed. More specifically, when the tensile modulus of the organic insulating material contained in the first insulating film 13 is 3.5 GPa or less, wear of the diamond bit of the grinding device 100 is suppressed. Therefore, according to the manufacturing method of the semiconductor device 1, the surface roughness of the first substrate 10 can be reduced.

[0051] In the manufacturing method of the semiconductor device 1, after at least a portion of the first insulating film 13 is cut by a flycutting method in step (b), the surface of the first insulating film 13 is polished in step (c). In this case, part of step (c) can be replaced by step (b). This makes it possible to reduce the surface roughness while shortening the processing time in step (c). Therefore, according to the manufacturing method of the semiconductor device 1, the surface roughness can be easily reduced.

[0052] In the manufacturing method of the semiconductor device 1, in step (c), the surface of the cut first insulating film 13 is polished by a CMP method. According to the manufacturing method of the semiconductor device 1, step (c) can be easily performed. Furthermore, the surface roughness of the first insulating film 13 can be more reliably reduced.

[0053] The method for manufacturing the semiconductor device 1 includes a step (d) of preparing a second substrate 20 having a second support substrate 21 and a second insulating film 23 provided on the second support substrate 21 and containing an organic insulating material, and a step (g1) of bonding the first insulating film 13 and the second insulating film 23 together after the step (d). In this case, for the reasons described above, the first substrate 10 and the second substrate 20 are bonded together with the surface roughness of the first substrate 10 reduced. Therefore, the method for manufacturing the semiconductor device 1 can improve the bonding strength between the first substrate 10 and the second substrate 20.

[0054] In the manufacturing method of semiconductor device 1, the tensile modulus is 3.0 GPa or less. In this case, wear of the grinding device 100 used in the flycutting method is further suppressed. That is, when the tensile modulus of the organic insulating material contained in first insulating film 13 is 3.5 GPa or less, wear of the diamond bit of grinding device 100 is further suppressed. Therefore, according to the manufacturing method of semiconductor device 1, the surface roughness of first substrate 10 can be further reduced.

[0055] In the method for manufacturing the semiconductor device 1, the organic insulating material contained in the first insulating film 13 is polyimide. According to the method for manufacturing the semiconductor device 1, it is possible to easily realize the first insulating film 13 in which the tensile modulus of the organic insulating material is 3.5 GPa or less.

[0056] Second Embodiment Next, a semiconductor device and a method for manufacturing the semiconductor device according to a second embodiment of the present disclosure will be described with reference to Figures 6 to 10. In the following description, differences from the first embodiment will be mainly described, and descriptions similar to or overlapping with the first embodiment may be omitted.

[0057] (Configuration of Semiconductor Device) First, the configuration of a semiconductor device 1A according to the second embodiment will be described with reference to FIG. 6 . FIG. 6 illustrates an example of a semiconductor device according to the second embodiment of the present disclosure. As shown in FIG. 6 , the semiconductor device 1A is, for example, an example of a semiconductor package, and includes a plurality of electrodes 2A, an insulating film 3A, a first substrate 10A, and a second substrate 20A. The electrode 2A is formed by bonding a first conductive portion 12A of the first substrate 10A to a second conductive portion 22A of the second substrate 20A (see FIG. 10 ), which will be described later. The insulating film 3A is formed by bonding a first insulating film 13A (first portion 131) of the first substrate 10A to a second insulating film 23A (first portion 231) of the second substrate 20A (see FIG. 10 ). Here, the tensile modulus of elasticity of the organic insulating material contained in the first insulating film 13A, which forms the insulating film 3A, is 3.5 GPa or less, and may be 3.0 GPa or less, or may be 2.8 GPa or less. Furthermore, when the second insulating film 23A also contains an organic insulating material, the tensile modulus of the organic insulating material may be 3.5 GPa or less, 3.0 GPa or less, or 2.8 GPa or less. The organic insulating material includes, for example, polyimide, a polyimide precursor, polyamideimide, benzocyclobutene (BCB), polybenzoxazole (PBO), or a PBO precursor.

[0058] In the semiconductor device 1A, a first substrate 10A and a second substrate 20A are bonded together. The first substrate 10A may include a semiconductor element. The second substrate 20A may also include a semiconductor element. These semiconductor elements may be electrically connected to each other via a plurality of electrodes 2A. The configurations of the semiconductor elements included in the first substrate 10A and the second substrate 20A are similar to the configurations of the semiconductor elements included in the first substrate 10 and the second substrate 20, and therefore detailed description thereof will be omitted.

[0059] (Method of Manufacturing Semiconductor Device) Next, a method of manufacturing the semiconductor device 1A will be described with reference to FIGS. 7 to 10. FIG. 7 is a cross-sectional view for explaining a method of manufacturing the semiconductor device shown in FIG. 6, showing an example of a step of preparing a first substrate. FIG. 8 is a cross-sectional view for explaining a method of manufacturing the semiconductor device shown in FIG. 6, showing an example of a step of cutting the second portion of the first insulating film by a flycutting method. FIG. 9 is a cross-sectional view for explaining a method of manufacturing the semiconductor device shown in FIG. 6, showing an example of a step of polishing the surface of the cut first insulating film. FIG. 10 is a cross-sectional view for explaining a method of manufacturing the semiconductor device shown in FIG. 6, showing an example of a step of bonding the first conductive portion and the second conductive portion.

[0060] The semiconductor device 1A can be manufactured through, for example, the following steps (h) to (n). That is, the method for manufacturing the semiconductor device 1 includes the following steps (h) to (n): h) preparing a substrate having a first support substrate, and a first conductive portion and a first insulating film provided on the first support substrate; i) cutting at least a portion of the first insulating film by a flycutting method without cutting the first conductive portion; j) polishing the surface of the first insulating film, which is a step performed after step (i); k) preparing a substrate having a second support substrate, and a second conductive portion and a second insulating film provided on the second support substrate; l) cutting at least a portion of the second insulating film by a flycutting method without cutting the second conductive portion; m) polishing the surface of the second insulating film, which is a step performed after step (l); and n) bonding the first substrate and the second substrate, which is a step performed after steps (j) and (m).

[0061] Furthermore, the step n) of bonding the first substrate and the second substrate includes the following steps: n1) bonding the first insulating film of the first substrate and the second insulating film of the second substrate, and n2) bonding the first conductive portion of the first substrate and the second conductive portion of the second substrate.

[0062] [Step (h)] Step (h) is a step of preparing a first substrate 10A. To prepare the first substrate 10A, first, a first support substrate 11A having a first conductive portion 12A and a first insulating film 13A is prepared. The configuration of the first support substrate 11A is similar to the configuration of the first support substrate 11, so a detailed description thereof will be omitted.

[0063] In the first substrate 10A prepared in step (h), the first conductive portion 12A is provided on the first support substrate 11A. Such a first conductive portion 12A is provided on the first support substrate 11A using, for example, a photosensitive material. In this case, the first conductive portion 12A is provided on the first support substrate 11A, for example, as follows. First, a base layer is provided on the first support substrate 11A. This base layer serves as a seed during electrolytic plating, which will be described later. Next, a resist layer is provided on the base layer. In one example, a film-like insulating material is attached to the first support substrate 11A by lamination processing as the resist layer.

[0064] This lamination process is carried out, for example, at a temperature set to 40°C or higher and 120°C or lower. For this reason, it is preferable to use a photosensitive insulating film that can be laminated at 40°C or higher and 120°C or lower as the film-like insulating material. By setting the lamination temperature to 40°C or higher, it is possible to prevent the tack (adhesiveness) of the photosensitive insulating film from becoming strong at room temperature, and to maintain good handleability of the photosensitive insulating film. By setting the lamination temperature of the photosensitive insulating film to 120°C or lower, it is possible to prevent warping of the photosensitive insulating film after the lamination process. Note that "room temperature" refers to approximately 25°C.

[0065] Next, the resist layer is exposed to light and developed to form openings therein. In this embodiment, a plurality of openings are formed in the resist layer corresponding to the plurality of electrodes 2A. Specifically, a predetermined exposure is performed with a photomask placed on the resist layer to form a pattern corresponding to the first conductive portion 12A. The exposed resist layer is then developed using a developer. This dissolves the unexposed portions of the resist layer, forming a plurality of openings. At this time, the base layer is exposed in the plurality of openings.

[0066] Next, the first conductive portion 12A is provided so that at least a portion thereof is located within the plurality of openings. In one example, the first conductive portion 12A is formed by electrolytic plating using the base layer exposed in the plurality of openings as a seed layer. The first conductive portion 12A is formed so that at least a portion thereof is located within the plurality of openings. In this case, the plurality of openings are filled by, for example, copper plating to form the first conductive portion 12A.

[0067] Next, the resist layer is peeled off from the first support substrate 11A using a commonly used peeling liquid.

[0068] The first conductive portion 12A provided by the above method is made of a copper pillar having a diameter of, for example, 0.5 μm or more and 20 μm or less. Furthermore, the volume resistivity of the first conductive portion 12A is, for example, 40 μΩ·cm or less from the viewpoint of transmission efficiency. From the viewpoint of suppressing the amount of heat generation, the volume resistivity is preferably 30 μΩ·cm or less. Furthermore, from the viewpoint of reliability, the volume resistivity is more preferably 20 μΩ·cm or less. The volume resistivity is typically 3 μΩ·cm or more.

[0069] In the first substrate 10A prepared in step (h), the first insulating film 13A is provided on the first support substrate 11A. More specifically, the first insulating film 13A is provided on the first support substrate 11A and the first conductive portion 12A. The first insulating film 13A also includes an organic insulating material. The tensile modulus of the organic insulating material is 3.5 GPa or less, or may be 3.0 GPa or less, or may be 2.8 GPa or less. Such a first insulating film 13A is provided, for example, by applying a liquid organic insulating material onto the surface of the first support substrate 11A and the surface of the first conductive portion 12A by spin coating.

[0070] The organic insulating material includes, for example, polyimide, a polyimide precursor, polyamideimide, benzocyclobutene (BCB), polybenzoxazole (PBO), or a PBO precursor.

[0071] Furthermore, in the first substrate 10A prepared in step (h), the first insulating film 13A has a first portion 131 and a second portion 132. The first portion 131 covers the surface of the first support substrate 11A and the side surface of the first conductive portion 12A. The second portion 132 is located on the first portion 131 and covers the upper surface of the first conductive portion 12A. The thickness of the second portion 132 is, for example, not less than 0.5 μm and not more than 5 μm. The first portion 131 and the second portion 132 are provided integrally.

[0072] The thickness of the first insulating film 13A formed on the first support substrate 11A is, for example, 10 μm or less, preferably 5 μm or less, and more preferably 3 μm or less. The thickness of the first insulating film 13A may also be 1 μm or more. The thickness of the first insulating film 13A is, for example, the sum of the thickness of the first portion 131 and the thickness of the second portion 132. The first insulating film 13A may also be made of an inorganic material.

[0073] After the first insulating film 13A is provided, the first insulating film 13A may be heat-cured. The heating conditions in this case are the same as those for heat-curing the first insulating film 13A, and therefore a detailed description thereof will be omitted.

[0074] 7, the above-described step (h) prepares a substrate having a first support substrate 11A, and a first conductive portion 12A and a first insulating film 13A provided on the first support substrate 11A. Therefore, step (h) can also be said to include the steps of providing an underlayer on the first support substrate 11A, providing a resist layer on the underlayer, providing an opening in the resist layer by exposing and developing the resist layer, providing the first conductive portion 12A so that at least a portion of the first conductive portion 12A is located in the opening, and providing the first insulating film 13A on the first support substrate 11A and the first conductive portion 12A.

[0075] [Step (i)] Step (i) is a step of cutting the first insulating film 13A. In step (i), the first insulating film 13A is cut by a fly-cutting method. In one example, at least a portion of the first insulating film 13A is cut by the fly-cutting method without cutting the first conductive portion 12A.

[0076] In step (i) of this embodiment, the second portion 132 covering the upper surface of the first conductive portion 12A is cut by flycutting, while the first portion 131 of the first insulating film 13A covering the surface of the first support substrate 11A and the side surface of the first conductive portion 12A remains. More specifically, as shown in FIG. 8 , the second portion 132 is cut by flycutting so that the surface of the second portion 132 protrudes from the upper surface of the first conductive portion 12A (so that a portion of the second portion 132 remains). That is, in step (i) of this embodiment, the thickness of the second portion 132 is reduced by flycutting. Therefore, in step (i) of this embodiment, it can be said that a portion of the second portion 132 is removed by cutting. The thickness of the second portion 132 cut by flycutting is, for example, 0.5 μm or more and 20 μm or less. Therefore, at the time when step (i) in this embodiment is completed, the thickness of the second portion 132 is, for example, not less than 3.0 μm and not more than 10 μm.

[0077] In the fly-cutting method, as in the first embodiment, a grinding device 100 using, for example, a diamond tool is used. In this case, too, the second portion 132 is cut by moving the grinding device 100 in a predetermined direction on the first substrate 10A, as shown in Fig. 8. The cutting of the second portion 132 by the fly-cutting method can also be considered a planarization process. In addition, in step (i), etching or the like may be combined with the fly-cutting method.

[0078] At the end of step (i) in this embodiment, the surface roughness of the second portion 132 cut by the flycutting method is, for example, 10 nm or more and 100 nm or less. In this embodiment, the surface roughness is the arithmetic mean roughness (Ra) defined in JIS B 0601 2001. The surface roughness of the second portion 132 after cutting is measured by scanning a 100 μm × 100 μm area including the second portion 132 using, for example, a laser microscope ("LEXT OLS3000" manufactured by Olympus Corporation).

[0079] [Step (j)] Step (j) is a step of polishing the surface of the first insulating film 13A, and is performed after the grinding step (i). In step (j) of this embodiment, as shown in FIG. 9 , the remaining portion of the cut second portion 132 is polished so that the surface of the first portion 131 and the upper surface of the first conductive portion 12A are flush with each other. More specifically, by polishing the surface of the remaining portion of the cut second portion 132, the second portion 132 remaining after step (i) is removed, and the surface of the first portion 131 and the upper surface of the first conductive portion 12A are flush with each other. This exposes the upper surface of the first conductive portion 12A. In step (j) of this embodiment, after the surface of the first portion 131 and the upper surface of the first conductive portion 12A are flush with each other, the surface of the first portion 131 and the upper surface of the first conductive portion 12A are further polished.

[0080] The polishing in step (j) can also be performed using a grinder for electronic materials processing or a chemical mechanical polishing (CMP) method. In step (j) of this embodiment, the surface of the second portion 13b is polished by the CMP method. That is, in step (j) of this embodiment, the surface of the cut first insulating film 13A is polished by the CMP method. The CMP method uses, for example, a polishing device 110. In this case, as shown in FIG. 9 , the polishing device 110 is pressed against the surface of the second portion 132 and rotated, thereby polishing the surface of the second portion 132 through mechanical friction between the polishing liquid applied to the surface of the polishing device 110 and the second portion 132. The polishing of the surface of the second portion 132 by the CMP method can also be considered a planarization process.

[0081] At the time when step (j) in this embodiment is completed, the surface roughness of the first portion 131 is, for example, 0.5 nm or more and 3.0 nm or less due to the polishing described above. The surface roughness of the upper surface of the first conductive portion 12A is, for example, 0.5 nm or more and 3.0 nm or less. The surface roughness is the arithmetic mean roughness (Ra) defined in JIS B 0601 2001. The surface roughness of the first portion 131 after polishing and the surface roughness of the upper surface of the first conductive portion 12A are measured, for example, by the same method as that for the surface roughness of the second portion 132 after cutting.

[0082] [Step (k)] Step (k) is a step of preparing a second substrate 20A different from the first substrate 10A. In step (k), the second substrate 20A is prepared, which has a second support substrate 21A, and a second conductive portion 22A and a second insulating film 23A provided on the second support substrate 21A. More specifically, the second substrate 20A has the second support substrate 21A, the second conductive portion 22A provided on the second support substrate 21A, and the second insulating film 23 provided on the second support substrate 21A and the second conductive portion 22A.

[0083] In the second substrate 20A prepared in step (k), the second insulating film 23A has a first portion 231 covering the surface of the second support substrate 21A and the side surfaces of the second conductive portions 22A, and a second portion located on the first portion 231 and covering the upper surfaces of the second conductive portions 22A. Here, the second insulating film 23A may contain an organic insulating material or an inorganic insulating material. When the second insulating film 23A contains an organic insulating material, the tensile modulus of elasticity of the organic insulating material may be 3.5 GPa or less, 3.0 GPa or less, or 2.8 GPa or less. The method for preparing the second substrate 20A is similar to the method for preparing the first substrate 10A, and therefore detailed description thereof will be omitted. However, the second substrate 20A is prepared through the above-described steps. The second substrate 20A does not need to have exactly the same configuration as the first substrate 10A, and the thickness or forming material of the second support substrate 21A and the thickness or forming material of the second insulating film 23A may be different from those of the first substrate 10A.

[0084] [Step (l)] Step (l) is a step of cutting the second insulating film 23A. The method of cutting the second insulating film 23A is similar to the method of cutting the first insulating film 13A, and therefore detailed description will be omitted. However, the second insulating film 23A is cut through the steps shown in Fig. 8. In step (l), the second portion of the second insulating film 23A may be cut so that the surface of the second portion of the second insulating film 23A protrudes from the upper surface of the second conductive portion 22A.

[0085] [Step (m)] Step (m) is a step of polishing the surface of the second insulating film 23A, and is performed after step (l). The method for polishing the surface of the second insulating film 23A is similar to the method for polishing the surface of the first insulating film 13A, and therefore detailed description will be omitted. However, the surface of the second insulating film 23A is cut through the steps shown in FIG. 9 . In step (m), the surface of the second portion of the second insulating film 23A may be polished so that the surface of the first portion 231 and the upper surface of the second conductive portion 22A are flush with each other. This exposes the upper surface of the second conductive portion 22A.

[0086] [Step (n)] Step (n) is a step of bonding the first substrate 10A and the second substrate 20A, and is performed after steps (j) and (m). In step (n), the first insulating film 13A of the first substrate 10A and the second insulating film 23A of the second substrate 20A are first bonded together. Here, at least one of the first substrate 10A and the second substrate 20A is aligned so that the first conductive portion 12A of the first substrate 10A and the second conductive portion 22A of the second substrate 20A face each other. Both the first substrate 10A and the second substrate 20A may be aligned. For such alignment, an alignment mark or the like may be provided on at least one of the first substrate 10A and the second substrate 20A.

[0087] When bonding the first substrate 10A and the second substrate 20A, organic substances or metal oxides adhering to the surfaces of the first substrate 10A and the second substrate 20A are removed, and then the second substrate 20A is aligned with the first substrate 10A. Once the alignment is complete, the first portion 131 of the first insulating film 13A and the first portion 231 of the second insulating film 23A are bonded together by hybrid bonding. The first portion 131 and the first portion 231 may be uniformly heated before bonding. Bonding the first portion 131 and the first portion 231 forms the insulating film 3A of the semiconductor device 1A, as shown in FIG. 6 .

[0088] The temperature difference between the first substrate 10A and the second substrate 20A during bonding is preferably, for example, 10°C or less. By heat bonding at such a uniform temperature, the first insulating film 13A is mechanically and firmly attached to the second insulating film 23A. Furthermore, because heat bonding is performed at a uniform temperature, positional deviation at the bonding points is unlikely to occur, allowing for highly accurate bonding. Note that the first substrate 10A and the second substrate 20A may also be bonded by other bonding methods, such as room temperature bonding.

[0089] Next, after the first insulating film 13A of the first substrate 10A and the second insulating film 23A of the second substrate 20A have been bonded, the first conductive portion 12A of the first substrate 10A and the second conductive portion 22A of the second substrate 20A are bonded. In this embodiment, as shown in FIG. 10 , after the bonding of the first insulating film 13A and the second insulating film 23A has been completed, a predetermined amount of heat and / or pressure is applied to bond the first conductive portion 12A and the second conductive portion 22A by hybrid bonding. When the first conductive portion 12A and the second conductive portion 22A are made of copper, the annealing temperature here is preferably 150° C. or higher and 400° C. or lower, and more preferably 200° C. or higher and 300° C. or lower. By such a bonding process, the first conductive portion 12A and the second conductive portion 22A are bonded to each other to form the electrode 2A, and the first conductive portion 12A and the second conductive portion 22A are mechanically and electrically firmly bonded to each other to form the electrode 2A. Note that the electrode bonding may be performed after bonding the first insulating film 13A and the second insulating film 23A, or may be performed simultaneously with bonding the first insulating film 13A and the second insulating film 23A.

[0090] Through the above steps, the semiconductor device 1A shown in FIG. 6 is manufactured.

[0091] In the method for manufacturing the semiconductor device 1A, the first substrate 10A has a first conductive portion 12A and a first insulating film 13A provided on a first support substrate 11A. The tensile modulus of the organic insulating material contained in the first insulating film 13A is 3.5 GPa or less. In step (i), at least a portion of the first insulating film 13A is cut by a fly-cutting method without cutting the first conductive portion 12A. According to the method for manufacturing the semiconductor device 1A, even when the first substrate 10A has the first conductive portion 12A, the surface roughness of the substrate can be reduced for the reasons described above.

[0092] The manufacturing method of the semiconductor device 1A includes cutting at least a portion of the first insulating film 13A by a fly-cutting method in step (i), and then polishing the surface of the first insulating film 13 in step (j). In this case, part of step (j) can be replaced by step (i). This makes it possible to reduce the surface roughness while shortening the processing time in step (j). Therefore, the manufacturing method of the semiconductor device 1A can easily reduce the surface roughness.

[0093] In the method for manufacturing the semiconductor device 1A, the surface of the cut first insulating film 13A is polished by CMP. According to the method for manufacturing the semiconductor device 1A, the step (j) can be easily performed. Furthermore, the surface roughness of the first insulating film 13A can be reliably reduced.

[0094] The method for manufacturing the semiconductor device 1A includes a step (k) of preparing a second substrate 20A having a second support substrate 21A, a second insulating film 23A containing an organic insulating material provided on the second support substrate 21A, and a second conductive portion 22A provided on the second support substrate 21A, and a step (n) of bonding the first conductive portion 12A and the second conductive portion 22A together after steps (j) and (m). In this case, for the reasons described above, the first substrate 10A and the second substrate 20A are bonded together while the surface roughness of the first substrate 10A is reduced. Therefore, the method for manufacturing the semiconductor device 1A can improve the bonding strength between the first substrate 10A and the second substrate 20A.

[0095] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0096] [Example 1] Two substrates each having a support substrate and a polyimide film containing polyimide and provided on the support substrate were prepared as substrates corresponding to the first substrate 10 in the above-described example. In each of the prepared substrates, the tensile modulus of elasticity of the polyimide contained in the polyimide film was 2.6 GPa.

[0097] Next, for each substrate, at least a portion of the polyimide film was cut by a flycutting method so as not to expose the surface of the support substrate, and then, for each substrate, the surface of the remaining portion of the cut polyimide film was polished by a CMP method so as not to expose the surface of the support substrate.

[0098] Next, a laser microscope (Olympus Corporation, "LEXT OLS3000") was used to scan a 100 μm × 100 μm area on the surface of each substrate to measure the surface roughness (arithmetic mean roughness (Ra) defined in JIS B 0601 2001) of the two substrates. The surface roughness of the substrates here includes the surface roughness of the polyimide film. Next, the two substrates were bonded together. The shear strength (bonding force) of the bonded two substrates was then measured. As a result, in Example 1, the surface roughness of each of the two substrates was 0.8 nm, and the shear strength was 30.0 MPa.

[0099] [Example 2] In Example 2, two substrates were prepared that were the same as those in Example 1, except that the tensile modulus of the polyimide contained in the polyimide film was 3.5 GPa. Next, for each substrate, at least a portion of the polyimide film was cut by a flycutting method so as not to expose the surface of the support substrate. Next, for each substrate, the surface of the remaining portion of the cut polyimide film was polished by a CMP method so as not to expose the surface of the support substrate.

[0100] Thereafter, the surface roughness of the two substrates was measured in the same manner as in Example 1. Next, the two substrates were bonded together. Thereafter, the shear strength of the bonded two substrates was measured. As a result, in Example 2, the surface roughness of the two substrates was 0.7 nm, and the shear strength was 22.1 MPa.

[0101] [Example 3] In Example 3, two substrates similar to those in Example 1 were prepared. Next, for each substrate, at least a portion of the polyimide film was cut by a flycutting method so that the surface of the support substrate was not exposed. In Example 3, the surface of the polyimide film was not polished by a CMP method. That is, in Example 3, only the cutting of the polyimide film was performed by a flycutting method.

[0102] Thereafter, the surface roughness of the two substrates was measured in the same manner as in Example 1. Next, the two substrates were bonded together. Thereafter, the shear strength of the bonded two substrates was measured. As a result, in Example 3, the surface roughness of the two substrates was 15.89 nm, and the shear strength was 19.4 MPa.

[0103] [Example 4] In Example 4, two substrates similar to those in Example 2 were prepared. Next, for each substrate, at least a portion of the polyimide film was cut by a flycutting method so that the surface of the support substrate was not exposed. In Example 4, the surface of the polyimide film was not polished by a CMP method. That is, in Example 4, only the cutting of the polyimide film was performed by a flycutting method.

[0104] Thereafter, the surface roughness of the two substrates was measured in the same manner as in Example 1. Next, the two substrates were bonded together. Thereafter, the shear strength of the bonded two substrates was measured. As a result, in Example 4, the surface roughness of the two substrates was 35.4 nm, and the shear strength was 8.2 MPa.

[0105] [Comparative Example 1] In Comparative Example 1, two substrates similar to those in Example 1 were prepared. Next, the surface of the polyimide film was polished by CMP so as not to expose the surface of the support substrate. In Comparative Example 1, cutting of the polyimide film by flycutting was not performed. That is, in Comparative Example 1, only polishing of the surface of the polyimide film by CMP was performed.

[0106] Thereafter, the surface roughness of the two substrates was measured in the same manner as in Example 1. Next, the two substrates were bonded together. The shear strength of the bonded two substrates was then measured. As a result, in Comparative Example 1, the surface roughness of the two substrates was 0.8 nm, and the shear strength was 27.1 MPa.

[0107] [Comparative Example 2] In Comparative Example 2, two substrates similar to those in Example 2 were prepared. Next, the surface of the polyimide film was polished by CMP so as not to expose the surface of the support substrate. In Comparative Example 2, cutting of the polyimide film by flycutting was not performed. That is, in Comparative Example 2, only polishing of the surface of the polyimide film by CMP was performed.

[0108] Thereafter, the surface roughness of the two substrates was measured in the same manner as in Example 1. Next, the two substrates were bonded together. The shear strength of the bonded two substrates was then measured. As a result, in Comparative Example 2, the surface roughness of the two substrates was 0.5 nm, and the shear strength was 28.0 MPa.

[0109] When performing general hybrid bonding, it is desirable that the surface roughness of the substrate be 50 nm or less, and preferably 1 nm or less. Therefore, in evaluating the surface roughness of each substrate in Experimental Examples 1, 2, 3, and 4 and Comparative Examples 1 and 2, a substrate with a surface roughness of 1 nm or less was rated as "good (A)," a substrate with a surface roughness of 50 nm or less was rated as "fair (B)," and a substrate with a surface roughness of more than 50 nm was rated as "fail (F)."

[0110] In Example 1, the surface roughness of the two substrates was 0.8 nm, and therefore Example 1 was evaluated as "A" for the substrate surface roughness. In Example 2, the surface roughness of the two substrates was 0.7 nm, and therefore Example 2 was evaluated as "A" for the substrate surface roughness. In Example 3, the surface roughness of the two substrates was 15.89 nm, and therefore Example 3 was evaluated as "B" for the substrate surface roughness. In Example 4, the surface roughness of the two substrates was 35.4 nm, and therefore Example 4 was evaluated as "B" for the substrate surface roughness. In Comparative Example 1, the surface roughness of the two substrates was 0.8 nm, and therefore Example 1 was evaluated as "A" for the substrate surface roughness. In Comparative Example 2, the surface roughness of the two substrates was 0.5 nm, and therefore Example 2 was evaluated as "A" for the substrate surface roughness.

[0111] Furthermore, after performing general hybrid bonding, it is desirable that the shear strength between the bonded substrates be 5 MPa or more, and preferably 20 MPa or more. Therefore, when evaluating the shear strength after bonding with another substrate in Experimental Examples 1, 2, 3, and 4 and Comparative Examples 1 and 2, a shear strength of 20 MPa or more was evaluated as "good (A)," a shear strength of 5 MPa or more was evaluated as "fair (B)," and a shear strength of less than 5 MPa was evaluated as "fail (F)."

[0112] In Example 1, the shear strength was 30.0 MPa, and therefore Example 1 was rated as "A" for shear strength. In Example 2, the shear strength was 22.1 MPa, and therefore Example 2 was rated as "A" for shear strength. In Example 3, the shear strength was 19.4 MPa, and therefore Example 3 was rated as "B" for shear strength. In Example 4, the shear strength was 8.2 MPa, and therefore Example 4 was rated as "B" for shear strength. In Comparative Example 1, the shear strength was 27.1 MPa, and therefore Comparative Example 1 was rated as "A" for shear strength. In Comparative Example 2, the shear strength was 28.0 MPa, and therefore Comparative Example 2 was rated as "A" for shear strength.

[0113] The results of Examples 1, 2, 3, and 4 and Comparative Examples 1 and 2 are summarized in Table 1 below.

[0114] First, let us focus on the surface roughness. As shown in Table 1, there were no Examples or Comparative Examples in which the surface roughness of the substrate was rated "F." Therefore, it can be seen that when the tensile modulus of elasticity of the polyimide (organic insulating material) contained in the polyimide film (insulating film) is 3.5 GPa or less, the surface roughness of the substrate can be reduced even by the method using the flycut method.

[0115] Furthermore, Examples 1 and 2, in which the polyimide film was cut by the flycutting method and then the surface of the polyimide film was polished by CMP, and Comparative Examples 1 and 2, in which only the surface of the polyimide film was polished by CMP, were rated "A" for surface roughness. On the other hand, Examples 3 and 4, in which the polyimide film surface was not polished by CMP, were rated "B" for surface roughness. Therefore, it can be seen that when the tensile modulus of the polyimide (organic insulating material) contained in the polyimide film (insulating film) is 3.5 GPa or less and the polyimide film (insulating film) is cut by the flycutting method and then the surface of the polyimide film (insulating film) is polished by CMP, the surface roughness of the substrate can be further reduced.

[0116] Next, we will focus on shear strength. Here, the smaller the surface roughness of the substrate, the better the bond strength between substrates bonded by hybrid bonding. Therefore, as with the surface roughness of the substrate, there were no examples or comparative examples that were rated "F" for shear strength. From the above, it can be seen that the shear strength between bonded substrates can be improved when the tensile modulus of the polyimide (organic insulating material) contained in the polyimide film (insulating film) is 3.5 GPa or less.

[0117] Furthermore, in Examples 1 and 2 and Comparative Examples 1 and 2, in which the surface roughness was judged to be "A," the shear strength was also judged to be "A." On the other hand, in Examples 3 and 4, in which the surface roughness was judged to be "B," the shear strength was also judged to be "B." Therefore, it can be seen that the shear strength of the bonded substrates can be further improved when the tensile modulus of the polyimide (organic insulating material) contained in the polyimide film (insulating film) is 3.5 GPa or less, and when the polyimide film (insulating film) is cut by the flycutting method and then the surface of the polyimide film (insulating film) is polished by the CMP method.

[0118] When comparing the flycutting method and the CMP method, the thickness of the polyimide film (insulating film) removed per unit time by the flycutting method tends to be greater than the same thickness removed by the CMP method. Therefore, when removing the same thickness of polyimide film, the time required by the flycutting method is expected to be shorter than the time required by the CMP method. That is, the processing time in Examples 1 and 2, in which the polyimide film was cut by the flycutting method and then polished by the CMP method, is expected to be shorter than the processing time in Comparative Examples 1 and 2, in which the polyimide film was only polished by the CMP method. Therefore, it is understood that by replacing part of the process of polishing the polyimide film by the CMP method with the process of cutting the polyimide film by the flycutting method, the processing time in the polishing process can be shortened.

[0119] Although the embodiments of the present disclosure have been described above, the present invention is not limited to the above-described embodiments, and appropriate modifications may be made without departing from the spirit of the present invention.

[0120] In the second embodiment, the first conductive portion 12A and the second conductive portion 22A are formed by electrolytic plating, but this is not limiting. For example, the first conductive portion 12A and the second conductive portion 22A may be formed by at least one of sputtering and electroless plating. Alternatively, the first conductive portion 12A and the second conductive portion 22A may be formed by combining at least one of sputtering, electroplating, and electroless plating with a copper paste application process and a sintering process.

[0121] In the second embodiment, in step (i), the second portion 132 covering the upper surface of the first conductive portion 12A is cut by flycutting while leaving the first portion 131 of the first insulating film 13A covering the surface of the first support substrate 11A and the side surface of the first conductive portion 12A. However, step (i) is not limited to this. For example, in step (i), the second portion 132 may be cut by flycutting so that the surface of the first portion 131 and the upper surface of the first conductive portion 12A are flush with each other. That is, in step (i), the entire second portion 13b may be removed by cutting using the flycutting method. In this case, in step (j), the surface of the first portion 131 may be polished. Furthermore, in step (j), the upper surface of the first conductive portion 12A may also be polished in addition to the surface of the first portion 131.

[0122] In step (i), when second portion 132 is cut so that the surface of first portion 131 and the upper surface of first conductive portion 12A are flush with each other, it is possible to further reduce the working time in step (j) while also reducing the surface roughness. Therefore, in this case, it is possible to reduce the surface roughness even more easily.

[0123] 1, 1A...semiconductor device, 10, 10A...first substrate, 11, 11A...first support substrate, 12A...first conductive portion, 13, 13A...first insulating film, 20, 20A...second substrate, 21, 21A...second support substrate, 22A...second conductive portion, 23, 23A...second insulating film.

Claims

1. A method for manufacturing a semiconductor device, comprising the steps of: preparing a first substrate having a first support substrate and a first insulating film disposed on the first support substrate and including an organic insulating material; and cutting at least a portion of the first insulating film by a fly-cutting method, wherein the organic insulating material has a tensile modulus of elasticity of 3.5 GPa or less.

2. The method for manufacturing a semiconductor device according to claim 1, further comprising the step of polishing a surface of said first insulating film, said polishing step being carried out after said cutting step.

3. The method for manufacturing a semiconductor device according to claim 2, wherein in the polishing step, the surface of the cut first insulating film is polished by a CMP method.

4. A method for manufacturing a semiconductor device as claimed in any one of claims 1 to 3, wherein the first substrate further has a first conductive portion provided on the first support substrate, and in the cutting step, at least a portion of the first insulating film is cut by a fly-cutting method without cutting the first conductive portion.

5. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, further comprising the steps of: preparing a second substrate having a second support substrate and a second insulating film provided on the second support substrate; and bonding the first insulating film and the second insulating film.

6. The method for manufacturing a semiconductor device according to claim 5, wherein the first substrate further has a first conductive portion provided on the first support substrate, the second substrate further has a second conductive portion provided on the second support substrate, and the bonding step further bonds the first conductive portion and the second conductive portion.

7. The method for manufacturing a semiconductor device according to any one of claims 1 to 6, wherein the organic insulating material has a tensile modulus of elasticity of 3.0 GPa or less.

8. The method for manufacturing a semiconductor device according to any one of claims 1 to 7, wherein the organic insulating material includes polyimide.

9. A semiconductor device comprising: a first substrate having a first support substrate and a first insulating film provided on the first support substrate and including an organic insulating material; a second substrate having a second support substrate and a second insulating film provided on the second support substrate, wherein the first insulating film and the second insulating film are bonded together; and the organic insulating material has a tensile modulus of elasticity of 3.5 GPa or less.

10. The semiconductor device according to claim 9, wherein the first substrate further has a first conductive portion provided on the first support substrate, the second substrate further has a second conductive portion provided on the second support substrate, and an electrode is formed by joining the first conductive portion and the second conductive portion.

11. The semiconductor device according to claim 9 or 10, wherein the organic insulating material has a tensile modulus of elasticity of 3.0 GPa or less.

12. The semiconductor device according to any one of claims 9 to 11, wherein the organic insulating material includes polyimide.

13. The semiconductor device according to any one of claims 9 to 12, wherein the second insulating film contains an organic insulating material, and the tensile modulus of elasticity of the organic insulating material of the second insulating film is 3.5 GPa or less.

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