Semiconductor device and method for manufacturing the same

Abstract

To provide a semiconductor device suitable for appropriate peeling of a substrate, and a method for manufacturing the semiconductor device.SOLUTION: According to one embodiment, there is provided a semiconductor device comprising a substrate, a first film, a second film, and a third film. The first film is arranged on the principal surface side of the substrate. The second film is formed on the opposite side of the substrate across the first film. A principal surface of the second film comes into contact with a principal surface of the first film. The third film is arranged on the opposite side of the first film across the second film. A principal surface on the substrate side in the third film includes a two-dimensionally distributed salient or a recess. A principal surface on the opposite side of the substrate in the third film is flat. An absorption rate of infrared light of the second film is greater than an absorption rate of infrared light of the third film. A thermal expansion coefficient of the third film differs from a thermal expansion coefficient of the second film.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present embodiment relates to a semiconductor device and a method for manufacturing the semiconductor device. [Background technology]

[0002] When manufacturing a semiconductor device, two substrates are bonded together and then one of the two substrates is peeled off. It is desirable that this substrate peeling be performed appropriately. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5725430 [Patent Document 2] International Publication No. 2014 / 163188 [Patent Document 3] International Publication No. 2015 / 156381 [Patent Document 4] International Publication No. 2013 / 058222 [Patent Document 5] International Publication No. 2014 / 017369 [Patent Document 6] International Publication No. 2019 / 004469 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one embodiment is to provide a semiconductor device suitable for appropriately separating a substrate, and a method for manufacturing the semiconductor device. [Means for solving the problem]

[0005] According to one embodiment, there is provided a semiconductor device having a substrate, a first film, a second film, and a third film, wherein the first film is disposed on a main surface side of the substrate. The first film has a first major surface opposite the substrate. The membrane of 2 is Second Main surface The second main surface has a No. 1 of On the main surface Joined The third membrane is disposed on the opposite side of the first membrane with the second membrane therebetween. The first and second principal surfaces are directly bonded to each other, with atoms of the first and second principal surfaces being bonded to each other by hydrogen bonds or covalent bonds. The main surface of the third film facing the substrate has two-dimensionally distributed convex or concave portions. The main surface of the third film opposite the substrate is flat. The infrared light absorptance of the second film is higher than that of the third film. The thermal expansion coefficient of the third film is different from that of the second film. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a cross-sectional view showing a configuration of a semiconductor device according to an embodiment. [Figure 2] 1 is a flowchart showing a method for manufacturing a semiconductor device according to an embodiment. [Figure 3] 1A to 1C are cross-sectional views showing a method for manufacturing a semiconductor device according to an embodiment. [Figure 4] 1A to 1C are cross-sectional views showing a method for manufacturing a semiconductor device according to an embodiment. [Figure 5] 1A to 1C are cross-sectional views showing a method for manufacturing a semiconductor device according to an embodiment. [Figure 6] 1A to 1C are cross-sectional views showing a method for manufacturing a semiconductor device according to an embodiment. [Figure 7] 1A to 1C are cross-sectional views showing a method for manufacturing a semiconductor device according to an embodiment. [Figure 8] 1A to 1C are plan views showing a method for manufacturing a semiconductor device according to an embodiment. [Figure 9] 1A to 1C are cross-sectional views showing a method for manufacturing a semiconductor device according to an embodiment. [Figure 10] 5A to 5C are cross-sectional views showing a method for manufacturing a semiconductor device according to a first modified example of the embodiment. [Figure 11] 5A to 5C are cross-sectional views showing a method for manufacturing a semiconductor device according to a first modified example of the embodiment. [Figure 12] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a second modified example of the embodiment. [Figure 13] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a second modified example of the embodiment. [Figure 14]10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a third modified example of the embodiment. [Figure 15] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a third modified example of the embodiment. [Figure 16] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a third modified example of the embodiment. [Figure 17] FIG. 10 is a cross-sectional view showing the configuration of a semiconductor device according to a fourth modified example of the embodiment. [Figure 18] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a fourth modified example of the embodiment. [Figure 19] 10A to 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to a fourth modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, a semiconductor device according to an embodiment will be described in detail with reference to the accompanying drawings, but the present invention is not limited to the embodiment.

[0008] (Embodiment) The semiconductor device according to the embodiment is formed by bonding two substrates, and has a structure suitable for reusing the substrate that is removed after bonding. Bonding two substrates is also called laminating two substrates.

[0009] For example, the semiconductor device 1 is configured as shown in Fig. 1. Fig. 1 is a cross-sectional view showing the configuration of the semiconductor device 1. In the following, the direction perpendicular to the main surface 2a of the substrate 2 is defined as the Z direction, and two directions perpendicular to each other in a plane perpendicular to the Z direction are defined as the X direction and the Y direction.

[0010] As shown in Figure 1, the semiconductor device 1 has a substrate 2, a film 3, a film 4, and a film 5. The substrate 2 has a plate shape extending in the XY direction. The substrate 2 has a main surface 2a on the +Z side and a main surface 2b on the -Z side. The main surface 2a and the main surface 2b each extend in the XY direction. The substrate 2 is made of a material containing a semiconductor (e.g., silicon) as a main component.

[0011] The film 3 is disposed on the +Z side (main surface 2a side) of the substrate 2. The film 3 extends in the XY directions along the main surface 2a. The film 3 has a main surface 3a on the +Z side and a main surface 3b on the -Z side. The main surfaces 3a and 3b each extend substantially flat in the XY directions. The film 3 may be formed of a material containing an insulator as its main component, or may be formed of a material containing a semiconductor oxide (e.g., silicon oxide) as its main component.

[0012] 1 illustrates, for simplicity, a configuration in which the film 3 covers the main surface 2a of the substrate 2, but other films may be interposed between the film 3 and the substrate 2. For example, a stacked body in which conductive layers and insulating layers are repeatedly stacked may be disposed between the film 3 and the substrate 2, and a semiconductor film may extend in the Z direction within the stacked body to form a three-dimensional memory cell array.

[0013] The film 4 is disposed on the opposite side of the substrate 2 with the film 3 therebetween. The film 4 is disposed on the +Z side of the substrate 2 and the film 3. The film 4 extends in the XY direction along the main surface 2a. The film 4 has a main surface 4a on the +Z side and a main surface 4b on the -Z side. The main surfaces 4a and 4b each extend in the XY direction. The film 4 can be formed of any material having a higher absorptance of infrared light than the substrate 2 and the film 5. The film 4 may also be formed of any material having a higher absorptance of a laser wavelength (preferably 1117 nm or longer, more preferably around 9300 nm or 10600 nm) suitable for the film 4 to function as a laser absorption layer than the substrate 2 and the film 5. The film 4 may be formed of a material whose main component is an insulator, or a material whose main component is a semiconductor oxide (e.g., silicon oxide).

[0014] The principal surface 3a and the principal surface 4b extend flatly in the XY directions and are in contact with each other. Atoms of the principal surface 3a of the film 3 and atoms of the principal surface 4b of the film 4 may be bonded by hydrogen bonds or covalent bonds. As will be described later, the semiconductor device 1 is formed by bonding two substrates, and the principal surfaces 3a and 4b are the bonding surfaces.

[0015] Film 5 is disposed on the opposite side of film 3 with film 4 in between. Film 5 is disposed on the +Z side of substrate 2, film 3, and film 4. Film 5 extends in the XY direction along main surface 2a. Film 5 has main surface 5a on the +Z side and main surface 5b on the -Z side. Main surface 5a and main surface 5b each extend in the XY direction. Main surface 5a extends flat in the XY direction.

[0016] Film 5 may be formed of any material having a lower absorptance of infrared light than film 4 and a higher thermal expansion coefficient than film 4. Film 5 may be formed of any material having a lower absorptance of infrared light than film 4 and a higher thermal expansion coefficient than film 4 at a laser wavelength (preferably 1117 nm or more, more preferably around 9300 nm or 10600 nm, etc.) suitable for film 4 to function as a laser absorbing layer.

[0017] The thermal expansion coefficient of film 5 is greater than that of substrate 100 (see FIG. 3(f)), which is disposed on the +Z side of film 5 during the manufacturing process of semiconductor device 1. However, since substrate 100 does not remain in the structure of semiconductor device 1, if substrate 100 is formed of the same material as substrate 2, the thermal expansion coefficient of film 5 can be indirectly made greater than that of substrate 100 by making the thermal expansion coefficient of film 5 greater than that of substrate 2.

[0018] When film 4 covers main surface 5b of film 5, film 5 may be formed of any material having a lower absorptance of infrared light than film 4 and a higher thermal expansion coefficient than film 4. Film 5 may be formed of any material having a lower absorptance of a laser wavelength (preferably 1117 nm or more, more preferably near 9300 nm or 10600 nm) suitable for film 4 to function as a laser absorption layer than film 4 and a higher thermal expansion coefficient than film 4. Film 5 may be formed of a material containing a semiconductor polycrystalline material (e.g., polycrystalline silicon) as a main component, or may be formed of a material containing a semiconductor amorphous material (e.g., amorphous silicon) as a main component.

[0019] When the film 4 covers the main surface 5b of the film 5, the main surface 4a and the main surface 5b each have two-dimensionally distributed convex portions or concave portions (see FIG. 8). The main surface 4a has a flat surface 4a1 and multiple concave portions 4a2. The flat surface 4a1 extends in the XY direction and constitutes the main portion of the main surface 4a. The concave portions 4a2 are recessed from the flat surface 4a1 toward the inside (-Z side) of the film 4. The main surface 5b has a flat surface 5b1 and multiple convex portions 5b2. The flat surface 5b1 extends in the XY direction and constitutes the main portion of the main surface 5b. The multiple convex portions 5b2 are arranged spaced apart from each other in the XY direction. The convex portions 5b2 protrude from the flat surface 5b1 toward the outside (-Z side) of the film 5 in correspondence with the concave portions 4a2.

[0020] 1 illustrates a configuration in which film 4 covers main surface 5b of film 5 for simplicity, but another film may be interposed between film 4 and film 5 as long as the film has a certain degree of thermal conductivity. For example, a semiconductor layer, a conductive layer, an insulating layer, etc. may be stacked between film 4 and film 5 to form a CMOS structure, thereby configuring a control circuit for controlling the memory cell array. In this case, the main surface of the other film covering main surface 5b of film 5 may have two-dimensionally distributed recesses corresponding to main surface 4a shown in FIG. 1.

[0021] As will be described later, in the manufacturing process of the semiconductor device 1, the film 4 functions as a laser absorbing layer, and the film 5 functions as a layer that undergoes local thermal expansion in response to local heat generation in the laser absorbing layer (film 4). Each of the multiple protrusions 5b2 on the main surface 5b is a structure formed by local thermal expansion.

[0022] Next, a method for manufacturing the semiconductor device 1 will be described with reference to Figs. 2 to 9. Fig. 2 is a flowchart showing a method for manufacturing the semiconductor device 1. Figs. 3(a) to 7 and Figs. 9(a) to 9(e) are YZ cross-sectional views showing the method for manufacturing the semiconductor device 1. Fig. 8 is an XY plan view showing the method for manufacturing the semiconductor device 1.

[0023] In the manufacturing method of the semiconductor device 1, preparation of a lower substrate (S1) and preparation of an upper substrate (S2) are performed in parallel, as shown in Fig. 2. The lower substrate is the substrate that is disposed on the -Z side of the two substrates to be joined when they are joined. The upper substrate is the substrate that is disposed on the +Z side of the two substrates to be joined when they are joined.

[0024] In the preparation of the lower substrate (S1), as shown in Fig. 3(a), a substrate (lower substrate) 2 is prepared. The substrate 2 may be formed of a material containing a semiconductor (e.g., silicon) as a main component that is substantially free of impurities.

[0025] 3(b), a film 3 is deposited by a CVD method or the like on the main surface 2a side (+Z side) of the substrate 2. The film 3 may be formed of a material containing an insulating material as a main component, or may be formed of a material containing a semiconductor oxide (e.g., silicon oxide) as a main component.

[0026] In preparing the upper substrate (S2), a substrate (upper substrate) 100 is prepared as shown in Fig. 3(c). The substrate 100 may be formed from a material containing a semiconductor (e.g., silicon) as its main component and substantially free of impurities.

[0027] As shown in FIG. 3(d), a film 5 is deposited on the principal surface 100b side (-Z side) of the substrate 100 by a CVD method or the like. The film 5 may be formed of any material having a lower infrared light absorption rate than the film 4 and a higher thermal expansion coefficient than the substrate 100. The film 5 may be formed of any material having a lower absorption rate than the film 4 at a laser wavelength (preferably 1117 nm or more, more preferably near 9300 nm or 10600 nm) suitable for the film 4 to function as a laser absorption layer and a higher thermal expansion coefficient than the substrate 100. The film 5 may be formed of a material whose main component is a semiconductor polycrystalline material (e.g., polycrystalline silicon), or may be formed of a material whose main component is a semiconductor amorphous material (e.g., amorphous silicon).

[0028] As shown in FIG. 3( e), film 4 is deposited on the −Z side of film 5 by a CVD method or the like. Film 4 can be formed of any material that has a higher infrared light absorption rate than film 5. Film 4 may be formed of any material that has a higher absorption rate than film 5 and substrate 100 at a laser wavelength (preferably 1117 nm or more, more preferably around 9300 nm or 10600 nm) suitable for film 4 to function as a laser absorption layer. Film 4 may be formed of a material primarily containing an insulator, or may be formed of a material primarily containing a semiconductor oxide (e.g., silicon oxide).

[0029] As shown in Fig. 2, once the preparation of the lower substrate (S1) and the preparation of the upper substrate (S2) are both completed, the upper and lower substrates are bonded (S3). The +Z side principal surface 3a of film 3 (see Fig. 3(b)) and the -Z side principal surface 4b of film 4 (see Fig. 3(e)) are each activated by plasma irradiation or the like, and as shown in Fig. 3(f), substrate 2 and substrate 100 are arranged facing each other in the Z direction so that principal surfaces 3a and 4b face each other. As shown in Fig. 4(a), substrate 2 and substrate 100 are brought closer to each other in the Z direction, and the principal surface 3a on the substrate 2 side and the principal surface 4b on the substrate 100 side are bonded. At this time, atoms on principal surface 3a and atoms on principal surface 4b are bonded by hydrogen bonds or the like, and substrate 2 and substrate 100 are temporarily bonded.

[0030] Therefore, as shown in Fig. 2, a heat treatment (annealing) is performed at a relatively low temperature (S4). In the heat treatment (annealing), substrate 2 and substrate 100 are heated as a whole, as indicated by the dotted arrows in Fig. 4(b). In the heat treatment, for example, substrate 2 and substrate 100 are each heated to a relatively low temperature (i.e., an allowable temperature for the device structure, for example, about 200°C) for a predetermined time. At this time, water molecules escape from the interface, and atoms of main surface 3a and atoms of main surface 4b are bonded by covalent bonds or the like, and substrate 2 and substrate 100 are finally bonded.

[0031] After step S4 shown in FIG. 2 is completed, infrared laser light 200 is irradiated from the substrate 100 side so that the focal point is located near the film 4 (S5). The laser light is irradiated with infrared laser light 200 in a wavelength range in which the light absorption rate of the film 4, which serves as the laser absorption layer, is higher than that of the other films 5 and the substrate 100 (preferably 1117 nm or more, more preferably around 9300 nm or 10600 nm, when the laser absorption layer is a silicon oxide film). A pulsed laser is used as the infrared laser light 200. Absorption of the infrared laser light 200 occurs depending on the absorption coefficient and thickness of the substrate or film, and in this structure, the highest laser absorption occurs in the film 4, which serves as the laser absorption layer. The pulse width of the infrared laser light 200 may be low frequency, on the order of 1 to 100 kHz.

[0032] At this time, the infrared laser light 200 is irradiated so that a plurality of irradiated portions are two-dimensionally distributed within the film 4. The infrared laser light 200 is irradiated so that the plurality of irradiated portions are spaced apart from one another in the XY plane direction (see FIG. 8). The irradiation interval of the infrared laser light 200 is adjusted to an appropriate interval for peeling, taking into consideration the influence of heat accumulation due to local heat generation in the film 4.

[0033] 5(a), an XY plane position to be irradiated with infrared laser light 200 is determined, and the focal point of the infrared laser light 200 is adjusted to be located within the film 4. The absorptance of the infrared laser light 200 in the film 4 is greater than that of the substrate 100, and is greater than that of the film 5. As a result, the infrared laser light 200 irradiated onto the film 4 through the substrate 100 and the film 5 is efficiently absorbed at the irradiated location within the film 4, causing local heat generation (local heating) in the film 4 at that XY plane position.

[0034] As shown in FIG. 5(b), the localized heat generated in the film 4 is transferred to the film 5, causing it to expand at that XY plane position. The thermal expansion coefficient of the film 5 is greater than that of the substrate 100, which is in turn greater than that of the film 4. As a result, at that XY plane position, the expansion of the film 5 forms a convex portion 5a2 protruding toward the +Z side in the +Z-side main surface 5a of the film 5, and a convex portion 4b2 protruding toward the -Z side in the -Z-side main surface 5b. Accordingly, a concave portion 100b2 recessed toward the +Z side is formed in the -Z-side main surface 100b of the substrate 100, and a concave portion 4a2 recessed toward the -Z side is formed in the +Z-side main surface 4a of the film 4.

[0035] As shown in Figure 5(c), the XY plane position to be irradiated with the infrared laser light 200 is determined to be a position shifted in the XY plane direction from the XY plane position in Figure 5(a), and the focal point of the infrared laser light 200 is adjusted to be located within the film 4. The absorptance of the infrared laser light 200 by the film 4 is greater than that of the substrate 100, and is greater than that of the film 5. As a result, the infrared laser light 200 irradiated onto the film 4 through the substrate 100 and the film 5 is efficiently absorbed at the irradiated location within the film 4, causing local heat generation (local heating) in the film 4 at that XY plane position.

[0036] As shown in FIG. 6(a), the localized heat generated in the film 4 is transferred to the film 5, causing it to expand at that XY plane position. The thermal expansion coefficient of the film 5 is greater than that of the substrate 100, which is in turn greater than that of the film 4. As a result, at that XY plane position, the expansion of the film 5 forms a convex portion 5a2 protruding toward the +Z side within the +Z-side main surface 5a of the film 5, and a convex portion 4b2 protruding toward the -Z side within the -Z-side main surface 5b. Accordingly, a concave portion 100b2 recessed toward the +Z side is formed within the -Z-side main surface 100b of the substrate 100, and a concave portion 4a2 recessed toward the -Z side is formed within the +Z-side main surface 4a of the film 4.

[0037] The same processes as those shown in FIGS. 5(c) and 6(a) are repeated while shifting the position on the XY plane to be irradiated.

[0038] 6(b), the final XY plane position to be irradiated with the infrared laser light 200 is determined, and the focus of the infrared laser light 200 is adjusted to be located within the film 4. The absorptance of the infrared laser light 200 in the film 4 is greater than that of the substrate 100, and greater than that of the film 5. As a result, the infrared laser light 200 irradiated onto the film 4 through the substrate 100 and the film 5 is efficiently absorbed at the irradiated location within the film 4, causing localized heat generation (local heating) in the film 4 at the final XY plane position.

[0039] As shown in FIG. 6(c), the localized heat generated in the film 4 is transferred to the film 5, causing it to expand at the final XY plane position. The thermal expansion coefficient of the film 5 is greater than that of the substrate 100, which is in turn greater than that of the film 4. As a result, at the final XY plane position, the expansion of the film 5 forms a convex portion 5a2 protruding toward the +Z side in the +Z-side main surface 5a of the film 5, and a convex portion 4b2 protruding toward the -Z side in the -Z-side main surface 5b. Accordingly, a concave portion 100b2 recessed toward the +Z side is formed in the -Z-side main surface 100b of the substrate 100, and a concave portion 4a2 recessed toward the -Z side is formed in the +Z-side main surface 4a of the film 4.

[0040] By irradiating the film 4 with the infrared laser light 200 so that multiple irradiated portions are distributed two-dimensionally, the main surface 5a on the +Z side of the film 5 has two-dimensionally distributed protrusions, as shown in Figures 7 and 8. On the main surface 5a, multiple protrusions 5b2 are arranged spaced apart from each other in the XY directions. This can generate local stresses in the main surface 5a, as indicated by the dotted arrows in Figures 7 and 8, such that each of the multiple protrusions 5a2 on the main surface 5a pushes the substrate 100 outward in the XY directions near the main surface 100b.

[0041] Note that local stresses occur at multiple locations spaced apart in the X and Y directions at the interface between film 5 and substrate 100 and at the interface between film 5 and film 4. If the difference in thermal expansion coefficient between film 5 and substrate 100 is greater than the difference in thermal expansion coefficient between film 5 and film 4, the local stresses occurring at the interface between film 5 and substrate 100 will be greater than the local stresses occurring at the interface between film 5 and film 4. For simplification, Figures 7 and 8 selectively show the relatively large local stresses occurring at the interface between film 5 and substrate 100.

[0042] That is, local stress occurs at multiple locations spaced apart in the XY directions at the interface between the film 5 and the substrate 100, causing the bonding state at the interface to become non-uniform and weakening the bonding strength at the interface. At this time, the interface between the film 5 and the substrate 100 becomes a surface that is prone to peeling.

[0043] In response to this, peeling occurs at the interface between film 5 and substrate 100 (S6). In peeling, as shown in FIG. 9(a), substrate 100 is peeled from stack 6 in which films 3, 4, and 5 are stacked on substrate 2. For example, the tip of blade member 300 is inserted into the interface between main surface 5a of film 5 and main surface 100b of substrate 100. The tip of blade member 300 has a sharp shape forming an acute angle. Because the bonding force at the interface is weakened, the substrate 100 is easily peeled from stack 6 with a relatively small stress caused by the insertion of the tip of blade member 300.

[0044] In consideration of subsequent processing, the peeled surface of the laminate 6 is treated (S7) as shown in FIG. 2. In the laminate 6, as shown in FIG. 9(b), a plurality of protrusions 5a2 are distributed in the XY direction on the main surface 5a on the +Z side of the film 5. The main surface 5a is polished and flattened by a CMP method or the like. As a result, as shown in FIG. 9(c), a semiconductor device 1 (see FIG. 1) is obtained in which the films 3, 4, and 5 are stacked on the substrate 2 and the main surface 5a of the film 5 is flattened.

[0045] On the other hand, the peeled substrate 100 is reused (S8) as shown in Fig. 2. The substrate 100 may be reused as an upper substrate 100 as indicated by the solid arrow in Fig. 2.

[0046] As shown in FIG. 9(d), immediately after peeling, the substrate 100 has a plurality of recesses 100b2 distributed in the XY direction on the -Z side of the main surface 100b. The main surface 100b is polished and flattened by a method such as CMP. This results in a substrate 100 with a flattened main surface 100b, as shown in FIG. 9(e). Since the main surface 100b of the substrate 100 shown in FIG. 9(e) is flattened, it can be easily reused as, for example, the upper substrate 100.

[0047] The peeled substrate 100 may be reused as the lower substrate 2 instead of the upper substrate 100, as indicated by the dotted arrow in FIG.

[0048] As described above, in this embodiment, after the substrate 2 on which the film 3 is laminated and the substrate 100 on which the films 5 and 4 are laminated are bonded, the infrared laser light 200 is irradiated from the substrate 100 side so that the focal point is located near the film 4. For example, the infrared laser light 200 is irradiated so that multiple irradiated portions are two-dimensionally distributed within the film 4. This allows local stress to be generated at multiple two-dimensionally separated locations at the interface between the film 4 and the substrate 100, for example, thereby weakening the bonding force at the interface. As a result, the substrate 100 can be peeled off with small stress by the blade member 300 or the like, thereby obtaining the semiconductor device 1 and the substrate 100. This allows the semiconductor device 1 and the substrate 100 to be obtained while suppressing damage during peeling, thereby improving the manufacturing yield of the semiconductor device 1 and easily reusing the substrate 100. In other words, the substrate 100 can be appropriately peeled off during the manufacturing of the semiconductor device 1.

[0049] Furthermore, in this embodiment, the semiconductor device 1 has films 3, 4, and 5 stacked on a substrate 2, the substrate-facing main surface 5b of the film 5 having two-dimensionally distributed protrusions 5b2, and the main surface 5a of the film 5 being flattened. The infrared light absorptance of the film 4 is higher than that of the film 5. The thermal expansion coefficient of the film 5 is higher than that of the film 4. This configuration is suitable for weakening the bonding strength at the interface between the film 5 and the substrate 100 with infrared laser light 200 after bonding multiple substrates 2, 100, thereby peeling off the substrate 100. This configuration can provide a semiconductor device 1 suitable for appropriately peeling off the substrate 100.

[0050] For example, when manufacturing a semiconductor device by bonding a plurality of substrates, some of the substrates may be removed by grinding. In this case, the removed substrates are discarded.

[0051] In contrast, in this embodiment, the removed substrate 100 can be reused, so that the cost of preparing a new substrate 100 can be reduced, and a significant cost reduction can be expected.

[0052] Alternatively, when manufacturing a semiconductor device by bonding multiple substrates, the substrate to be removed may be bonded via a release layer, and then the entire substrate may be heated to a high temperature to weaken the release layer through thermal modification, causing the substrate to peel off from the release layer. In this case, the entire substrate is heated to a high temperature, which may cause thermal damage to the device structure (e.g., the structure of the memory cell array and the structure of the control circuit).

[0053] In contrast, in this embodiment, the heating of the film 4 by the infrared laser light 200 is localized heating, and the heat treatment of the entire substrate is limited to a relatively low temperature (e.g., about 200°C), so that thermal damage to the device structure (e.g., the structure of the memory cell array and the structure of the control circuit) can be suppressed.

[0054] Alternatively, when manufacturing a semiconductor device by bonding multiple substrates, a substrate may be mechanically removed by inserting a blade member, which may cause mechanical damage such as cracks.

[0055] In contrast, in this embodiment, the infrared laser light 200 is irradiated so that multiple irradiation areas are distributed two-dimensionally within the film 4, weakening the bonding strength at the interface between the film 5 and the substrate 100, and then the substrate 100 is removed with a small stress caused by inserting a blade member. This makes it possible to suppress mechanical damage to the substrate being removed.

[0056] The debonding may be performed using a debonder. For example, the debonder has a lower stage, an upper stage facing the lower stage in the Z direction, and a blade member configured to be insertable into the space between the lower stage and the upper stage. For example, in the process shown in FIG. 9(a), with the lower stage holding the substrate 2 and the upper stage holding the substrate 100, the tip of the blade member is inserted from the XY direction at the Z position of the interface between the film 5 and the substrate 100, and the upper stage moves the substrate 100 away from the lower stage in the +Z direction. This allows the process shown in FIG. 9(a) to be performed.

[0057] As a first modification, the substrate 100 may be peeled off at the -Z principal surface 5b of the film 5 instead of at the +Z principal surface 5a of the film 5. For example, if the difference in thermal expansion coefficients between the film 5 and the film 4 is greater than the difference in thermal expansion coefficients between the film 5 and the substrate 100, the local stress generated at the interface between the film 5 and the film 4 is greater than the local stress generated at the interface between the film 5 and the substrate 100. In this case, after the process shown in FIG. 6(c), as indicated by the dotted arrows in FIG. 10, local stress may be generated in which each of the multiple protrusions 5b2 on the principal surface 5b pushes the film 4 outward in the XY direction near the principal surface 4a. That is, local stress generated at multiple locations spaced apart from each other in the XY direction at the interface between the film 5 and the film 4 causes non-uniformity in the bonding state at the interface, weakening the bonding strength at the interface. In this case, the interface between the film 5 and the film 4 becomes a surface that is prone to peeling.

[0058] In response to this, peeling occurs at the interface between film 5 and film 4 (S6). In peeling, as shown in FIG. 11(a), stack 7, in which film 5 is stacked on substrate 100, is peeled from stack 6a, in which film 3 and film 4 are stacked on substrate 2. For example, the tip of blade member 300 is inserted into the interface between main surface 5b of film 5 and main surface 4a of film 4. The tip of blade member 300 has a sharp shape forming an acute angle. Because the bonding force at the interface is weakened, stack 7 is easily peeled from stack 6a with a relatively small stress caused by the insertion of the tip of blade member 300.

[0059] In consideration of subsequent processing, the peeled surface of the laminate 6a is treated (S7). In the laminate 6a, as shown in FIG. 11(b), a plurality of recesses 4a2 are distributed in the XY direction on the main surface 4a on the +Z side of the film 4. The main surface 4a is polished and flattened by a CMP method or the like. As a result, as shown in FIG. 11(c), a semiconductor device 1a is obtained in which the film 3 and the film 4 are stacked on the substrate 2 and the main surface 4a of the film 4 is flattened.

[0060] Meanwhile, the peeled substrate 100 is reused (S8). As shown in FIG. 11(d), immediately after peeling, the substrate 100 has a -Z-side main surface 100b covered with a film 5, and has a plurality of recesses 100b2 distributed in the XY direction. After the film 5 is removed by dry etching or wet etching, the main surface 100b is polished and planarized by a CMP method or the like. This results in a substrate 100 with a planarized main surface 100b, as shown in FIG. 11(e). Since the main surface 100b of the substrate 100 shown in FIG. 11(e) is planarized, it can be easily reused as, for example, an upper substrate 100.

[0061] In this way, the manufacturing method shown in Figures 10 and 11 also makes it possible to obtain the semiconductor device 1 and the substrate 100 while suppressing damage during peeling, thereby improving the manufacturing yield of the semiconductor device 1 and making it easy to reuse the substrate 100.

[0062] Further, some measures may be taken to promote peeling. For example, as a second modified example, the steps shown in Figures 3(c) to 3(e) may be replaced by the steps shown in Figures 12(a) to 12(d).

[0063] 3(a) and 3(b), the following process is performed. In preparation of the upper substrate (S2), after a substrate (upper substrate) 100 is prepared as shown in FIG. 12(a), impurities are introduced into a region of the substrate 100 near the main surface 100b by ion implantation or the like as shown in FIG. 12(b). The impurities are those that lower the thermal expansion coefficient of a semiconductor (e.g., silicon). The impurities may be those that lower the thermal expansion coefficient of the semiconductor below that of the film 4. As a result, an impurity region 101 is formed on the −Z side of the base region 102 in the substrate 100. The impurity region 101 may be formed over substantially the entire main surface 100b. A film 5 shown in FIG. 12(c) is deposited on the main surface 100b side (−Z side) of the substrate 100, and a film 4 shown in FIG. 12(d) is deposited on the −Z side of the film 5.

[0064] Here, the thermal expansion coefficient of the impurity region 101 is smaller than that of the underlying region 102. The thermal expansion coefficient of the film 5 is larger than that of the underlying region 102. As a result, the difference in thermal expansion coefficient between the film 5 and the substrate 100 (impurity region 101) is larger than the difference in thermal expansion coefficient between the film 5 and the substrate 100 in the embodiment.

[0065] 3(f) to 6(c), a large local stress may be generated in the vicinity of the main surface 100b, where each of the plurality of protrusions 5b2 on the main surface 5b pushes the substrate 100 outward in the XY directions, as indicated by the dotted arrows in FIG. 13. That is, local stress is generated at a plurality of locations spaced apart from each other in the XY directions at the interface between the film 5 and the impurity region 101, increasing the non-uniformity of the bonding state at the interface and further weakening the bonding strength at the interface. In this case, the interface between the film 5 and the impurity region 101 (the interface between the film 5 and the substrate 100) becomes a surface that is more susceptible to peeling than the interface between the film 5 and the substrate 100 in the embodiment.

[0066] Accordingly, as in the embodiment, peeling occurs at the interface between the film 5 and the impurity region 101 (the interface between the film 5 and the substrate 100) (S6), the semiconductor device 1a is obtained, and the peeled substrate 100 is reused (S8).

[0067] 12 and 13, the difference in thermal expansion coefficient between the film 5 and the substrate 100 can be increased, and the interface between the film 5 and the substrate 100 can be more easily peeled off. This allows the subsequent peeling of the substrate 100 to be performed with even less stress by the blade member 300 or the like, and therefore makes it possible to obtain the semiconductor device 1 and the substrate 100 while further suppressing damage during peeling.

[0068] Alternatively, the promotion of peeling may be achieved by adding a film 8 instead of introducing impurities into the substrate 100. For example, as a third modified example, the steps shown in Figures 3(c) to 3(e) may be replaced by the steps shown in Figures 14(a) to 14(d).

[0069] 3(a) and 3(b), the following process is performed. In preparation of the upper substrate (S2), a substrate (upper substrate) 100 is prepared as shown in FIG. 14(a), and then a film 8 shown in FIG. 14(b) is deposited on the main surface 100b side (-Z side) of the substrate 100. The film 8 may be formed of a material having a thermal expansion coefficient smaller than that of the substrate 100. The film 8 may also be formed of a material having a thermal expansion coefficient smaller than that of the substrate 100 and smaller than that of the film 4. A film 5 shown in FIG. 14(c) is deposited on the main surface 8b side (-Z side) of the film 8. The film 5 may be formed of a material having a thermal expansion coefficient larger than that of the substrate 100 (for example, a semiconductor polycrystalline material or a semiconductor amorphous material). A film 4 shown in FIG. 15(d) is deposited on the -Z side of the film 5.

[0070] Here, the thermal expansion coefficient of film 8 is smaller than that of substrate 100. The thermal expansion coefficient of film 5 is larger than that of substrate 100. As a result, the difference in thermal expansion coefficient between film 5 and film 8 is larger than the difference in thermal expansion coefficient between film 5 and substrate 100 in the embodiment.

[0071] 3(f) to 6(c), a large local stress may be generated in the vicinity of the -Z-side principal surface 8b, where each of the multiple protrusions 5a2 on the principal surface 5a pushes the film 8 outward in the XY direction, as shown by the dotted arrows in FIG. 15. That is, local stress is generated at multiple locations spaced apart from each other in the XY direction at the interface between the film 5 and the film 8, increasing the non-uniformity of the bonding state at the interface and further weakening the bonding strength at the interface. In this case, the interface between the film 5 and the film 8 becomes a surface that is more susceptible to peeling than the interface between the film 5 and the substrate 100 in the embodiment.

[0072] In response to this, peeling occurs at the interface between film 5 and film 8 (S6). In peeling, as shown in FIG. 16(a), stack 7b, in which film 8 is stacked on substrate 100, is peeled from stack 6b, in which films 3, 4, and 5 are stacked on substrate 2. For example, the tip of blade member 300 is inserted into the interface between main surface 8b of film 8 and main surface 5a of film 5. The tip of blade member 300 has a sharp shape forming an acute angle. Because the bonding force at the interface is weakened, stack 7b is easily peeled from stack 6b with a relatively small stress caused by the insertion of the tip of blade member 300.

[0073] In consideration of subsequent processing, the peeled surface of the laminate 6b is treated (S7). In the laminate 6b, as shown in FIG. 16(b), a plurality of protrusions 5a2 are distributed in the XY direction on the main surface 5a on the +Z side of the film 5. The main surface 5a is polished and flattened by a CMP method or the like. As a result, as shown in FIG. 16(c), a semiconductor device 1 is obtained in which the films 3, 4, and 5 are stacked on the substrate 2 and the main surface 5a of the film 5 is flattened.

[0074] Meanwhile, the peeled substrate 100 is reused (S8). Immediately after peeling, the substrate 100 has a main surface 100b on the -Z side covered with a film 8, as shown in FIG. 16(d). The film 8 is removed by dry etching or wet etching. This results in the substrate 100 as shown in FIG. 16(e). The substrate 100 shown in FIG. 16(e) can be easily reused, for example, as the upper substrate 100. Furthermore, since polishing by a CMP method or the like is not required, the substrate 100 can be reused in almost its original state.

[0075] 14 to 16, the difference in thermal expansion coefficient between film 5 and film 8 can be increased, and the interface between film 5 and film 8 can be realized as an interface that is easier to peel than the interface between film 5 and substrate 100 in the embodiment. This allows the subsequent peeling of substrate 100 to be performed with less stress by blade member 300 or the like, and therefore allows semiconductor device 1 and substrate 100 to be obtained while further suppressing damage during peeling.

[0076] Alternatively, the semiconductor device 1c may be configured so that the difference in thermal expansion coefficient is achieved by adding a film with a small thermal expansion coefficient. For example, as a fourth modification, the semiconductor device 1c has a film 9 instead of the film 5 (see FIG. 1), as shown in FIG. 17. FIG. 17 is a cross-sectional view showing the configuration of the semiconductor device 1c according to the fourth modification of the embodiment.

[0077] Film 9 is disposed on the opposite side of film 3 with film 4 in between. Film 9 is disposed on the +Z side of substrate 2, film 3, and film 4. Film 9 extends in the XY direction along main surface 2a. Film 9 has main surface 9a on the +Z side and main surface 9b on the -Z side. Main surface 9a and main surface 9b each extend in the XY direction. Main surface 9a extends flat in the XY direction.

[0078] Film 9 may be formed of any material having a lower infrared light absorption rate than film 4 and a lower thermal expansion coefficient than film 4. Film 9 may be formed of any material having a lower absorption rate than film 4 at a laser wavelength (preferably 1117 nm or more, more preferably around 9300 nm or 10600 nm, etc.) suitable for film 4 to function as a laser absorption layer and a lower thermal expansion coefficient than film 4.

[0079] The thermal expansion coefficient of film 9 is greater than that of substrate 100 (see FIG. 18) that is disposed on the +Z side of film 9 during the manufacturing process of semiconductor device 1c. However, since substrate 100 does not remain in the structure of semiconductor device 1c, if substrate 100 is formed of the same material as substrate 2, the thermal expansion coefficient of film 9 can be indirectly made greater than that of substrate 100 by making the thermal expansion coefficient of film 9 greater than that of substrate 2.

[0080] When film 4 covers main surface 9b of film 9, film 9 may be formed of any material having a lower absorptance of infrared light than film 4 and a higher thermal expansion coefficient than substrate 2. Film 9 may be formed of any material having a lower absorptance of infrared light than film 4 and a lower thermal expansion coefficient than film 4 at a laser wavelength (preferably 1117 nm or more, more preferably around 9300 nm or 10600 nm, etc.) suitable for film 4 to function as a laser absorption layer.

[0081] When the film 4 covers the principal surface 9b of the film 9, the principal surface 4a and the principal surface 9b each have two-dimensionally distributed convex portions or concave portions (see FIG. 8). The principal surface 4a has a flat surface 4a1 and multiple convex portions 4a3. The flat surface 4a1 extends in the XY direction and constitutes the main portion of the principal surface 4a. The convex portions 4a3 protrude from the flat surface 4a1 to the outside (+Z side) of the film 4. The principal surface 9b has a flat surface 9b1 and multiple concave portions 9b3. The flat surface 9b1 extends in the XY direction and constitutes the main portion of the principal surface 9b. The multiple concave portions 9b3 are arranged spaced apart from each other in the XY direction. The concave portions 9b3 are recessed from the flat surface 9b1 toward the inside (+Z side) of the film 9 in correspondence with the convex portions 4a3.

[0082] 17 may be manufactured as shown in Figures 18 and 19. Figure 18 and Figures 19(a) to 19(e) are YZ cross-sectional views showing a method for manufacturing a semiconductor device according to a fourth modified example of the embodiment.

[0083] For example, in the description of the steps in FIGS. 3(a) to 6(c), film 5 is replaced with film 9, "a thermal expansion coefficient larger than that of substrate 100" is replaced with "a thermal expansion coefficient smaller than that of substrate 100," main surfaces 5a and 5b are replaced with main surfaces 9a and 9b, protrusions 5a2 and 5b2 are replaced with recesses 9a3 and 9b3, recess 100b2 is replaced with protrusion 100b3, and recess 4a2 is replaced with protrusion 4b3. When the steps in FIGS. 3(a) to 6(c) with these replacements are performed, after the step shown in FIG. 6(c), local stresses may be generated in which each of the multiple protrusions 100b3 on main surface 100b pushes film 9 outward in the XY directions near main surface 9a, as indicated by the dotted arrows in FIG. 18. That is, local stresses are generated at multiple locations spaced apart in the XY directions at the interface between film 9 and substrate 100, resulting in non-uniform bonding at the interface and weakening the bonding strength at the interface. At this time, the interface between the film 9 and the substrate 100 becomes a surface that is prone to peeling.

[0084] In response to this, peeling occurs at the interface between film 9 and substrate 100 (S6). In peeling, as shown in FIG. 19(a), substrate 100 is peeled from stack 6c in which films 3, 4, and 9 are stacked on substrate 2. For example, the tip of blade member 300 is inserted into the interface between main surface 100b of substrate 100 and main surface 9a of film 9. The tip of blade member 300 has a sharp shape forming an acute angle. Because the bonding force at the interface is weakened, the substrate 100 is easily peeled from stack 6c with a relatively small stress caused by the insertion of the tip of blade member 300.

[0085] In consideration of subsequent processing, the peeled surface of the laminate 6c is treated (S7). In the laminate 6c, as shown in FIG. 19(b), a plurality of recesses 9a3 are distributed in the XY direction on the main surface 9a on the +Z side of the film 9. The main surface 9a is polished and flattened by a CMP method or the like. As a result, as shown in FIG. 19(c), a semiconductor device 1c is obtained in which the films 3, 4, and 9 are stacked on the substrate 2 and the main surface 9a of the film 9 is flattened.

[0086] Meanwhile, the peeled substrate 100 is reused (S8). As shown in FIG. 19(d), immediately after peeling, the substrate 100 has a plurality of convex portions 100b3 distributed in the XY direction on the -Z side main surface 100b. The main surface 100b is polished and flattened by a CMP method or the like. This results in a substrate 100 with a flattened main surface 100b, as shown in FIG. 19(e). Since the main surface 100b of the substrate 100 shown in FIG. 19(e) is flattened, it can be easily reused as, for example, an upper substrate 100.

[0087] In this way, the manufacturing method shown in Figures 18 and 19 also makes it possible to obtain the semiconductor device 1c and the substrate 100 while suppressing damage during peeling, thereby improving the manufacturing yield of the semiconductor device 1c and making it easy to reuse the substrate 100.

[0088] Although not shown, the substrate 100 may be peeled off at the -Z principal surface 9b of the film 9 instead of at the +Z principal surface 9a of the film 9. For example, if the difference in thermal expansion coefficient between the film 9 and the film 4 is greater than the difference in thermal expansion coefficient between the film 9 and the substrate 100, the local stress generated at the interface between the film 9 and the film 4 is greater than the local stress generated at the interface between the film 9 and the substrate 100. In this case, after the process shown in FIG. 6(c), each of the multiple protrusions 4a3 (see FIG. 17) on the principal surface 4a may generate local stress that pushes the film 9 outward in the XY direction near the principal surface 9b. That is, local stress generated at multiple locations spaced apart from each other in the XY direction at the interface between the film 9 and the film 4 causes non-uniformity in the bonding state at the interface, weakening the bonding strength at the interface. In this case, the interface between the film 9 and the film 4 becomes a surface that is prone to peeling. In response to this, similarly to the first modification, peeling (S6), processing of the peeled surface (S7), and re-release of the peeled substrate 100 (S8) can be performed.

[0089] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0090] 1,1a,1c semiconductor device, 2,100 substrate, 3-5,9 film.

Claims

1. A substrate; a first film disposed on the main surface side of the substrate and having a first main surface on the opposite side to the substrate; a second film having a second main surface on the substrate side and bonded to the first main surface; a third membrane disposed on the opposite side of the first membrane with the second membrane therebetween; Equipped with the first main surface and the second main surface are directly bonded surfaces, Atoms of the first main surface and atoms of the second main surface are bonded by hydrogen bonds or covalent bonds, a main surface of the third film facing the substrate has two-dimensionally distributed convex portions or concave portions; a main surface of the third film opposite to the substrate is flat; the second film has a higher absorptance of infrared light than the third film, The thermal expansion coefficient of the third film is different from the thermal expansion coefficient of the second film. Semiconductor device.

2. the first film and the second film each include a semiconductor oxide; The third film comprises a semiconductor polycrystalline material or a semiconductor amorphous material. The semiconductor device according to claim 1 .

3. The thermal expansion coefficient of the third film is greater than the thermal expansion coefficient of the second film. The semiconductor device according to claim 1 .

4. The thermal expansion coefficient of the third film is smaller than the thermal expansion coefficient of the second film. The semiconductor device according to claim 1 .

5. the infrared light is an infrared pulsed laser light, The absorption rate of the infrared pulsed laser light in the second film is greater than the absorption rate of the infrared pulsed laser light in the third film. The semiconductor device according to claim 1 .

6. laminating a first film on a first substrate, and laminating a third film and a second film on a second substrate; bonding a main surface of the first film opposite to the first substrate to a main surface of the second film opposite to the second substrate; irradiating the second substrate with infrared laser light from the second substrate side so that the focal point is located near the second film; peeling off the second substrate; treating the release surface of the second substrate to obtain a reused second substrate; laminating a fifth film on a third substrate, and laminating a seventh film and a sixth film on the reused second substrate; bonding a major surface of the fifth film opposite the third substrate to a major surface of the sixth film opposite the reused second substrate; irradiating the recycled second substrate with infrared laser light from the side thereof so that the focal point is located near the sixth film; and peeling off the recycled second substrate; the absorptance of the infrared laser light in the second film is greater than the absorptance of the infrared laser light in the second substrate; the thermal expansion coefficient of the third film is different from the thermal expansion coefficient of a film in contact with the third film; an absorptance of the infrared laser light of the sixth film is greater than an absorptance of the infrared laser light of the reused second substrate; The seventh film has a thermal expansion coefficient different from that of a film in contact with the seventh film. A method for manufacturing a semiconductor device.

7. Irradiating so that the focal point is located near the second film includes irradiating the infrared laser light so that a plurality of irradiation portions are two-dimensionally distributed within the second film, Irradiating the sixth film so that the focal point is located near the sixth film includes irradiating the sixth film with infrared laser light so that a plurality of irradiation portions are two-dimensionally distributed within the sixth film. The method for manufacturing a semiconductor device according to claim 6 .

8. The infrared laser light is a pulse laser. The method for manufacturing a semiconductor device according to claim 7 .

9. a thermal expansion coefficient of the third film is different from a thermal expansion coefficient of the second substrate; peeling off the second substrate includes peeling off a main surface of the third film on a side of the second substrate; a thermal expansion coefficient of the seventh film is different from a thermal expansion coefficient of the reused second substrate; Peeling off the reused second substrate includes peeling off the seventh film from a main surface on the reused second substrate side. The method for manufacturing a semiconductor device according to claim 6 .

10. a thermal expansion coefficient of the third film is different from a thermal expansion coefficient of a film in contact with the second substrate on the opposite main surface thereof; peeling off the second substrate includes peeling off the third film from a main surface opposite to the second substrate; a thermal expansion coefficient of the seventh film is different from a thermal expansion coefficient of a film in contact with the seventh film on the opposite main surface of the reused second substrate; Peeling off the reused second substrate includes peeling off the seventh film at a major surface of the reused second substrate opposite the seventh film. The method for manufacturing a semiconductor device according to claim 6 .

11. laminating the third film and the second film on the second substrate includes laminating a fourth film, the third film, and the second film on the second substrate; the thermal expansion coefficient of the third film is greater than the thermal expansion coefficient of the second substrate; the fourth film has a thermal expansion coefficient smaller than the thermal expansion coefficient of the second substrate; peeling off the second substrate includes peeling off the fourth film at an interface between the third film and the fourth film, thereby peeling off the second substrate; laminating the seventh film and the sixth film on the reused second substrate includes laminating an eighth film, the seventh film, and the sixth film on the reused second substrate; the seventh film has a thermal expansion coefficient greater than the thermal expansion coefficient of the reused second substrate; a thermal expansion coefficient of the eighth film is smaller than a thermal expansion coefficient of the reused second substrate; Peeling off the reused second substrate includes peeling off the eighth film at an interface between the seventh film and the eighth film to peel off the reused second substrate. The method for manufacturing a semiconductor device according to claim 9 .

12. before laminating the third film and the second film on the second substrate, an impurity that reduces a thermal expansion coefficient is introduced into the second substrate; the thermal expansion coefficient of the third film is greater than the thermal expansion coefficient of the second film; peeling off the second substrate includes peeling off the second substrate at an interface between the third film and the second substrate; before laminating the seventh film and the sixth film on the reused second substrate, an impurity that reduces a thermal expansion coefficient is introduced into the reused second substrate; the seventh film has a thermal expansion coefficient greater than the thermal expansion coefficient of the sixth film; Peeling off the reused second substrate includes peeling off the reused second substrate at an interface between the seventh film and the reused second substrate. The method for manufacturing a semiconductor device according to claim 9 .

Images