Method for manufacturing semiconductor device

Abstract

This method for manufacturing a semiconductor device includes: preparing a composite substrate in which a first substrate and a second substrate are bonded together with a thermal conduction control film, a detachment promotion film, and a laser absorption film interposed therebetween; irradiating the laser absorption film with a laser; and separating the first substrate and the second substrate. The thermal conduction control film, the detachment promotion film, and the laser absorption film are layered in that order from the first substrate side; the thermal conductivity of the thermal conduction control film differs from the thermal conductivity of the detachment promotion film; and the thermal expansion coefficient of the detachment promotion film is greater than the thermal expansion coefficient of the laser absorption film.

Description

Semiconductor device manufacturing method

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

[0002] Patent Document 1 discloses a method for manufacturing a semiconductor device, including stacking a first film on a first substrate, stacking a fourth film, a third film, and a second film on a second substrate, bonding the first film and the second film, irradiating an infrared laser beam near the second film, and peeling off the second substrate at the interface between the third film and the fourth film. The thermal expansion coefficient of the third film is larger than that of the second substrate. The thermal expansion coefficient of the fourth film is smaller than that of the second substrate.

[0003] Japan Patent Publication No. 2023-87907

[0004] The technology according to the present disclosure appropriately separates the first substrate and the second substrate in a laminated substrate in which the first substrate and the second substrate are bonded together.

[0005] One aspect of the present disclosure is a method for manufacturing a semiconductor device, comprising: preparing a laminated substrate in which a first substrate and a second substrate are bonded via a heat conduction control film, a peeling-promoting film, and a laser absorbing film; irradiating the laser absorbing film with a laser; and separating the first substrate and the second substrate, wherein the heat conduction control film, the peeling-promoting film, and the laser absorbing film are stacked in this order from the first substrate side; the thermal conductivity of the heat conduction control film is different from the thermal conductivity of the peeling-promoting film; and the thermal expansion coefficient of the peeling-promoting film is greater than the thermal expansion coefficient of the laser absorbing film.

[0006] According to the present disclosure, in a laminated substrate in which a first substrate and a second substrate are bonded together, the first substrate and the second substrate can be appropriately separated.

[0007] FIG. 1 is a flow diagram showing the main steps of wafer processing; FIG. 2 is an explanatory diagram showing a state in which a first wafer and a second wafer are bonded to form an overlapped wafer; FIG. 3 is an explanatory diagram showing a state in which a laser absorbing film is irradiated with laser light; FIG. 4 is an explanatory diagram showing a state in which the first wafer and the second wafer are separated; FIG. 5 is an explanatory diagram showing a state in which the first wafer is reused; FIG. 6 is a flow diagram showing the main steps of laser processing; FIG. 7 is an explanatory diagram showing a state in which a peeling-promoting film expands locally; FIG. 8 is an explanatory diagram showing a state in which peeling occurs at the interface between the laser absorbing film and the peeling-promoting film;

[0008] In the manufacturing process of semiconductor devices, a device layer formed on the surface of a first semiconductor substrate (hereinafter referred to as "wafer") is transferred to a second wafer in an overlapped wafer formed by bonding two semiconductor substrates (hereinafter referred to as "wafers"). This transfer of the device layer from the first wafer to the second wafer is performed by irradiating the interior of the overlapped wafer with laser light to reduce the bonding strength between the first and second wafers, and then separating the first wafer from the second wafer. After separation, the first wafer is reused and bonded to the next second wafer.

[0009] In the semiconductor device manufacturing method disclosed in Patent Document 1, a first substrate having a first film stacked thereon is bonded to a second substrate having a fourth film, a third film, and a second film stacked thereon, and then the second substrate is peeled (separated) at the interface between the third film and the fourth film. That is, the second film and the third film are transferred from the second substrate to the first substrate. Furthermore, when peeling the second substrate, infrared laser light is irradiated near the second film to locally heat the second film. This local heating of the second film is transferred to the third film, causing the third film to expand. This weakens the bonding force at the interface between the third film and the fourth film, making the third film and the fourth film more easily peeled. The peeled second substrate is then reused.

[0010] However, in the semiconductor device manufacturing method disclosed in Patent Document 1, localized heating of the second film by infrared laser light may be transmitted to the second substrate via the third and fourth films. In such cases, the second substrate expands, resulting in the formation of localized irregularities that become defects on the surface of the second substrate (the surface on the fourth film side). To reuse this second substrate, it is necessary to remove the defects and flatten the surface, but this flattening process is time-consuming and costly. Furthermore, flattening the surface of the second substrate thins the second substrate, making it difficult to properly reuse the second substrate.

[0011] Patent Document 1 also discloses a method for manufacturing a semiconductor device in which a first substrate having a first film laminated thereon is bonded to a second substrate having only a third film and a second film laminated thereon, without a fourth film laminated thereon, and then the second substrate is peeled off at the interface between the third film and the second substrate. However, in this case, as in the above case, local heating of the second film by the infrared laser light is transmitted to the second substrate through the third film, causing the second substrate to expand and forming irregularities that become local defects on the surface of the second substrate.

[0012] The technology disclosed herein has been made in consideration of the above circumstances, and provides a method for appropriately separating a first substrate from a second substrate in a laminated substrate in which the first substrate and the second substrate are bonded together. Hereinafter, a method for manufacturing a semiconductor device according to this embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals, and redundant description will be omitted.

[0013] In the method for manufacturing a semiconductor device according to this embodiment, first, a first wafer W is prepared as a first substrate (St1 in FIG. 1), and a second wafer S is prepared as a second substrate (St2 in FIG. 1). The preparation of the first wafer W and the preparation of the second wafer S may be performed in parallel. Hereinafter, as shown in FIG. 2, the surface of the first wafer W that is to be bonded to the second wafer S is referred to as the front surface Wa, and the surface opposite the front surface Wa is referred to as the back surface Wb. Similarly, the surface of the second wafer S that is to be bonded to the first wafer W is referred to as the front surface Sa, and the surface opposite the front surface Sa is referred to as the back surface Sb.

[0014] The first wafer W prepared in St1 is a semiconductor wafer such as a silicon substrate. In one embodiment, the first wafer W has a substantially circular disk shape. As shown in FIG. 2A, a laminated film Mw, which is a stack of multiple films, is formed on the front surface Wa of the first wafer W. The laminated film Mw includes, in order from the front surface Wa side, a heat conduction control film R, a peeling promoting film Q, a laser absorbing film P, a device layer Dw, and a surface film Fw. Note that the heat conduction control film R, the peeling promoting film Q, the laser absorbing film P, the device layer Dw, and the surface film Fw are each formed on the first wafer W by, for example, a chemical vapor deposition (CVD) process in a film formation apparatus (not shown).

[0015] The device layer Dw includes a plurality of devices. The surface film Fw may be, for example, an oxide film (THOX film, SiO ２ film, TEOS film), SiC film, SiCN film, adhesive, etc.

[0016] As will be described later, the laser absorbing film P absorbs laser light (e.g., CO ２ The laser absorbing film P is made of, for example, an oxide film (SiO ２ However, there is no particular limitation as long as it absorbs laser light.

[0017] The peel-promoting film Q is formed to facilitate peeling of the first wafer W and the second wafer S, as will be described later. The laser light absorptance of the peel-promoting film Q is lower than that of the laser absorbing film P, or the peel-promoting film Q does not absorb laser light. The thermal expansion coefficient (volume expansion coefficient) of the peel-promoting film Q is higher than that of the laser absorbing film P and is also higher than that of the heat conduction control film R. The adhesion between the peel-promoting film Q and the heat conduction control film R is lower than that between the peel-promoting film Q and the laser absorbing film P. For example, a semiconductor polycrystalline material (e.g., polycrystalline silicon (polysilicon)), a semiconductor amorphous material (e.g., amorphous silicon), etc. is used for the peel-promoting film Q, but there is no particular limitation as long as it has the above-mentioned properties.

[0018] As will be described later, the heat conduction control film R is formed to control heat transfer to the first wafer W so that heat (thermal energy) from the laser absorbing film P due to the laser light is not transferred to the first wafer W. The laser light absorptance of the heat conduction control film R is lower than that of the laser absorbing film P, or the heat conduction control film R does not absorb laser light. The thermal conductivity of the heat conduction control film R is different from that of the peeling-promoting film Q and different from that of the first wafer W.

[0019] In the following description, the thermal conduction control film R having a thermal conductivity higher than that of the peeling-promoting film Q and higher than that of the first wafer W may be referred to as a high thermal conduction control film R1. For example, a graphene film or the like is used as the high thermal conduction control film R1, but there is no particular limitation as long as it has the above-mentioned properties.

[0020] Furthermore, a heat conduction control film having a heat conductivity lower than that of the peeling promoting film Q and lower than that of the first wafer W may be referred to as a low heat conduction control film R2. ２ O ３ , SiN, etc., are used, but there are no particular limitations as long as they have the above properties.

[0021] The second wafer S prepared in St2 is a semiconductor wafer such as a silicon substrate. In one embodiment, the second wafer S has a substantially circular disk shape. As shown in FIG. 2B, a laminated film Ms is formed on the surface Sa of the second wafer S. The laminated film Ms includes a device layer Ds and a surface film Fs, in this order from the surface Sa side. The device layer Ds and the surface film Fs are each formed on the second wafer S by, for example, a CVD process in a film formation apparatus (not shown).

[0022] The device layer Ds and the surface film Fs are respectively the same as the device layer Dw and the surface film Fw of the first wafer W. Note that the device layer Ds and the surface film Fs may not be formed on the surface Sa.

[0023] After preparing the first wafer W and the second wafer S as described above, the first wafer W and the second wafer S are bonded together to form a laminated wafer T as shown in FIG. 2C (St3 in FIG. 1). In St3, the surface film Fw of the first wafer W is bonded to the surface film Fs of the second wafer S. The bonding method for the first wafer W and the second wafer S is arbitrary. For example, the surface films Fw and Fs are modified by plasma treatment in a surface modification device (not shown), and then the surface films Fw and Fs are hydrophilized by supplying pure water to them in a surface hydrophilization device (not shown). After that, the surface films Fw and Fs are bonded together in a bonding device (not shown) by van der Waals forces and hydrogen bonds (intermolecular forces).

[0024] Next, as shown in Fig. 3, the laser absorbing film P is irradiated with laser light L (St4 in Fig. 1). In St4, a laser irradiation device (not shown) irradiates the laser absorbing film P or the interface between the laser absorbing film P and the peeling promoting film Q with pulsed laser light. In this embodiment, the laser light is CO ２ Laser light, CO ２ The wavelength of the laser light is, for example, 8.9 μm to 11 μm. In this case, the laser light L may be irradiated in a spiral pattern over the entire surface of the laser absorbing film P in a plan view, or may be irradiated in a concentric ring pattern over the entire surface of the laser absorbing film P. The laser light L passes through the first wafer W, the peeling-promoting film Q, and the thermal conduction control film R from the rear surface Wb side of the first wafer W, and is absorbed in the laser absorbing film P. Then, this laser light L reduces the bonding strength at the interface between the laser absorbing film P and the peeling-promoting film Q.

[0025] In the following description, the interface inside the laminated wafer T where the bonding strength has decreased (in this embodiment, the interface between the laser absorbing film P and the peeling-promoting film Q) may be referred to as the "separation surface" in the technology of the present disclosure. Furthermore, in this embodiment, "decreased bonding strength" refers to a state where the bonding strength has decreased at least compared to before the irradiation of the laser light L, and includes peeling between the laser absorbing film P and the peeling-promoting film Q.

[0026] Furthermore, in St4, the laser absorbing film P is locally heated by the laser absorbing film P. This thermal energy is transferred to the thermal conduction control film R via the peeling-promoting film Q, but is not transferred to the first wafer W by the thermal conduction control film R. This makes it possible to suppress deformation of the first wafer W due to the thermal energy. Note that details of the effect of irradiation with laser light L, i.e., the effect of reducing the bonding strength between the laser absorbing film P and the peeling-promoting film Q, and the heat transfer control effect of the thermal conduction control film R will be described later.

[0027] Next, the first wafer W and the second wafer S are separated as shown in Fig. 4 (St5 in Fig. 1). In St5, in a separation device (not shown), the first wafer W and the second wafer S are separated from each other at the interface between the laser absorbing film P and the peeling-promoting film Q, the bonding strength of which has been reduced in St4.

[0028] The first wafer W and the second wafer S may be separated by any method. As an example, as shown in FIG. 4( a), a suction chuck 10 suction-holds the back surface Sb of the second wafer S, and a suction pad 11 suction-holds the front surface Wa of the first wafer W. Thereafter, as shown in FIG. 4( b), while the suction pad 11 suction-holds the first wafer W, the suction pad 11 is raised to separate the first wafer W and the second wafer S. At this time, because the bonding strength at the interface between the laser absorbing film P and the peeling-promoting film Q is reduced by the irradiation of the laser light L as described above, the first wafer W and the second wafer S can be separated without applying a large load.

[0029] Next, the separated surface of the separated second wafer S, i.e., the surface of the laser absorbing film P, is treated (St6 in FIG. 1 ). In St6, the surface of the laser absorbing film P may be cleaned, for example, in a cleaning device (not shown). Alternatively, the surface of the laser absorbing film P may be polished and planarized or removed, for example, in a polishing device (not shown) or an etching device (not shown). In this way, a semiconductor device is manufactured in which the laser absorbing film P, the device layer Dw, the surface film Fw, the surface film Sw, and the device layer Ds are stacked on the surface Sa of the second wafer S.

[0030] On the other hand, the separated first wafer W is reused (St7 in FIG. 1). The reuse process for the first wafer W can be carried out in one of two ways, for example.

[0031] The first pattern of the recycling process is to remove the peeling-promoting film Q and the heat conduction control film R formed on the front surface Wa of the first wafer W as shown in FIG. 5(a) (Step 71 in FIG. 1). In Step 71, the peeling-promoting film Q is first etched and removed in an etching device (not shown). The peeling-promoting film Q may be etched by either dry etching or wet etching. When the peeling-promoting film Q is made of, for example, polycrystalline silicon, the etching may be performed by using, for example, HF and HNO . ３ In this case, the peeling-promoting film Q has etching selectivity with respect to the heat conduction control film R, and the peeling-promoting film Q is selectively etched.

[0032] In St71, the heat conduction control film R is then etched and removed in an etching device (not shown). The heat conduction control film R may be etched by dry etching or wet etching. When a graphene film is used for the high heat conduction control film R1, which is the heat conduction control film R, the high heat conduction control film R1 is etched by heating in a hydrogen gas atmosphere. When a low heat conduction control film R2, which is the heat conduction control film R, is etched by heating in a hydrogen gas atmosphere, the low heat conduction control film R2 is etched by heating in a hydrogen gas atmosphere. ２ O ３ When is used, for example, H ３ P.O. ４ and HNO ３ When, for example, SiN is used for the low thermal conduction control film R2, which is the thermal conduction control film R, wet etching is performed using an etching solution containing, for example, HF, an ether-based solvent, and Z or a fluorinated ether-based solvent. The thermal conduction control film R has etching selectivity with respect to the first wafer W, and the thermal conduction control film R is selectively etched.

[0033] The first wafer W, from which the peeling-promoting film Q and the heat conduction control film R have been removed in St71, is then subjected to the same process as in St1, and the heat conduction control film R, the peeling-promoting film Q, the laser absorbing film P, the device layer Dw, and the surface film Fw are formed on the front surface Wa. In this way, the first wafer W is reused for the next second wafer S.

[0034] In addition, the first wafer W from which the peeling-promoting film Q and the heat conduction control film R have been removed in St71 is a bare wafer with no film formed on its surface Wa, and therefore may be reused as the second wafer S next.

[0035] 5B, the second pattern of the reuse process is to remove only the peel-promoting film Q formed on the front surface Wa of the first wafer W (St72 in FIG. 1). In St72, an etching process similar to that of St71 described above is performed, and the peel-promoting film Q is selectively etched. That is, the first wafer W is reused in a state in which the thermal conduction control film R remains on the front surface Wa. At this time, a CMP process may be performed to planarize the side of the thermal conduction control film R facing the peel-promoting film Q, or etching may be performed.

[0036] The first wafer W from which the peeling-promoting film Q has been removed in St71 is then subjected to the same process as in St1, and the peeling-promoting film Q, the laser absorbing film P, the device layer Dw, and the surface film Fw are formed on the thermal conduction control film R on the front surface Wa. In this way, the first wafer W is reused for the next second wafer S. In St71, if the laser absorbing film P is attached to the front surface Wa of the first wafer W, the laser absorbing film P may be removed.

[0037] Next, the effects of irradiation with laser light L (laser processing) in St4 described above, i.e., the effect of reducing the bonding strength between the laser absorbing film P and the peeling promoting film Q, and the effect of heat transfer control by the heat conduction control film R will be described.

[0038] 3, laser light L is irradiated from the back surface Wb side of the first wafer W (St40 in FIG. 6). The laser light L passes through the first wafer W, the heat conduction control film R, and the peeling promoting film Q, and is absorbed by the laser absorbing film P (St41 in FIG. 6).

[0039] The laser light L absorbed by the laser absorbing film P is converted into heat according to its energy distribution (St42 in FIG. 6). In other words, the absorption of the laser light L locally heats the laser absorbing film P, causing the temperature of the laser absorbing film P to rise. Most of the thermal energy generated in the laser absorbing film P by the absorption of the laser light L is transferred to the peel-promoting film Q (St43 in FIG. 6). This heat transfer from the laser absorbing film P causes the temperature of the interface between the laser absorbing film P and the peel-promoting film Q to rise.

[0040] When the thermal energy generated in the laser absorbing film P is transmitted to the peel-promoting film Q, the effect of this thermal energy, i.e., the increase in the interface temperature between the laser absorbing film P and the peel-promoting film Q, causes the peel-promoting film Q to locally expand in accordance with the temperature distribution in the area irradiated with the laser light L, as shown in Fig. 7 (St44 in Fig. 6). Specifically, the peel-promoting film Q undergoes plastic deformation into a downwardly convex shape toward the laser absorbing film P. Here, the thermal expansion coefficient of the peel-promoting film Q is greater than that of the laser absorbing film P and is also greater than that of the thermal conduction control film R. Therefore, the peel-promoting film Q locally expands at St44.

[0041] On the other hand, the thermal energy generated in the laser absorbing film P is also transferred to the thermal conduction control film R via the peeling-promoting film Q (St45 in FIG. 6). Then, the heat transfer is controlled in the thermal conduction control film R, and the transfer of the thermal energy to the first wafer W can be suppressed (St46 in FIG. 6).

[0042] For example, when a high thermal conductivity control film R1 is used as the thermal conductivity control film R, the thermal conductivity of the high thermal conductivity control film R1 is higher than that of the peeling promoting film Q and is also higher than that of the first wafer W. Therefore, the thermal energy generated in the laser absorption film P is diffused inside the high thermal conductivity control film R1, and localized heating can be suppressed. As a result, the transfer of thermal energy to the first wafer W can be suppressed.

[0043] Furthermore, for example, when a low thermal conduction control film R2 is used as the thermal conduction control film R, the thermal conductivity of the low thermal conduction control film R2 is lower than that of the peeling promoting film Q and is also lower than that of the first wafer W. For this reason, the laser absorbing film P makes it difficult for thermal energy to be transmitted to the low thermal conduction control film R2; in other words, the low thermal conduction control film R2 acts as a barrier against the thermal energy. As a result, it is possible to suppress the transmission of thermal energy to the first wafer W.

[0044] In St44, when the peel-promoting film Q (and the first wafer W) expands locally, the stress σ generated by the expansion of the peel-promoting film Q causes peeling at the interface between the laser absorbing film P and the peel-promoting film Q, which has low adhesion, as shown in Fig. 8 (St47 in Fig. 6). As a result, the bonding strength between the laser absorbing film P and the peel-promoting film Q decreases. Then, by irradiating the entire laser absorbing film P with laser light L, the peeling is continued over the entire interface between the laser absorbing film P and the peel-promoting film Q as shown in Fig. 9, thereby reducing the bonding strength over the entire surface of the laser absorbing film P and the peel-promoting film Q.

[0045] As described above, according to this embodiment, by reducing the bonding strength between the laser absorbing film P and the peeling-promoting film Q in St4 (St40 to St47), the laser absorbing film P and the peeling-promoting film Q (the first wafer W and the second wafer S) can be properly separated in St5. As a result, the device layer Dw formed on the first wafer W can be transferred to the second wafer S, and a semiconductor device can be properly manufactured.

[0046] Furthermore, in this embodiment, the first wafer W separated in St7 is reused, so the cost of preparing a new first wafer W can be reduced, thereby reducing the manufacturing cost of the semiconductor device.

[0047] In this embodiment, a heat conduction control film R is formed between the surface Wa of the first wafer W and the peeling-promoting film Q. When the laser absorbing film P is irradiated with laser light L in St4, thermal energy generated in the laser absorbing film P is transferred to the heat conduction control film R via the peeling-promoting film Q. At this time, heat transfer is controlled in the heat conduction control film R, and it is possible to suppress the transfer of thermal energy to the first wafer W. As a result, it is possible to suppress the formation of irregularities that could become defects on the surface Wa of the first wafer W, and the surface Wa is maintained flat. This eliminates the need to flatten the surface Wa to thin the first wafer W as in the conventional method, and allows the first wafer W to be appropriately reused.

[0048] Furthermore, in this embodiment, the peel-promoting film Q has etching selectivity with respect to the heat conduction control film R, and the heat conduction control film R has etching selectivity with respect to the first wafer W. Therefore, after selectively etching the peel-promoting film Q in St71, the heat conduction control film R can be selectively etched. Furthermore, the peel-promoting film Q can also be selectively etched in St72. Therefore, the first wafer W can be appropriately reused.

[0049] Even if the release-promoting film Q expands and plastically deforms in St4, the first wafer W can be appropriately reused as long as the release-promoting film Q can be appropriately etched in St7. Therefore, the technology from this perspective includes the following: a method for manufacturing a semiconductor device, comprising: preparing a laminated substrate in which a first substrate and a second substrate are bonded together via a thermal conduction control film, a release-promoting film, and a laser absorbing film; irradiating the laser absorbing film with a laser; and separating the first substrate and the second substrate, wherein the thermal conduction control film, the release-promoting film, and the laser absorbing film are stacked in this order from the first substrate side, the release-promoting film has etching selectivity with respect to the thermal conduction control film, and the thermal expansion coefficient of the release-promoting film is greater than the thermal expansion coefficient of the laser absorbing film.

[0050] Furthermore, the heat conduction control film R can be appropriately etched in St7 if the following conditions are met: The heat conduction control film has etching selectivity with respect to the first substrate.

[0051] In the above embodiment, the device layer Dw formed on the front surface Wa of the first wafer W is transferred to the second wafer S, that is, the entire surface of the first wafer W is separated from the second wafer S. In this regard, the technology according to the present disclosure can also be applied to the case where a part of the first wafer W is separated from the second wafer S.

[0052] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components involved in the combination, and also provides other functions and effects that are apparent to those skilled in the art from the description of this specification.

[0053] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0054] P Laser absorbing film Q Separation promoting film R Heat conduction control film S Second wafer T Overlapped wafer W First wafer

Claims

1. A method for manufacturing a semiconductor device, comprising: preparing a laminated substrate in which a first substrate and a second substrate are bonded via a heat conduction control film, a peeling promoting film, and a laser absorbing film; irradiating the laser absorbing film with a laser; and separating the first substrate and the second substrate, wherein the heat conduction control film, the peeling promoting film, and the laser absorbing film are stacked in that order from the first substrate side, the thermal conductivity of the heat conduction control film is different from the thermal conductivity of the peeling promoting film, and the thermal expansion coefficient of the peeling promoting film is greater than the thermal expansion coefficient of the laser absorbing film.

2. The method for manufacturing a semiconductor device according to claim 1, wherein when the first substrate and the second substrate are separated, the interface between the peeling-promoting film and the laser absorbing film becomes a separation surface.

3. The method for manufacturing a semiconductor device according to claim 1, comprising: removing the peeling-promoting film after separating the first substrate and the second substrate; and removing the heat conduction control film after removing the peeling-promoting film.

4. The method for manufacturing a semiconductor device according to claim 1, further comprising removing said peeling-promoting film after said first substrate and said second substrate are separated.

5. The method for manufacturing a semiconductor device according to claim 1, wherein the heat conduction control film has etching selectivity with respect to the first substrate.

6. The method for manufacturing a semiconductor device according to claim 1, wherein the peeling-promoting film has etching selectivity with respect to the heat conduction control film.

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