JP5771968B2 - Manufacturing method of semiconductor device, laminated support substrate for epitaxial growth, and laminated support substrate for device - Google Patents

Description

  The present invention relates to a method for manufacturing a semiconductor device, a laminated support substrate for epitaxial growth manufactured by the manufacturing method, and a stacked support substrate for a device.

  As a substrate for manufacturing a group III nitride semiconductor device such as a blue light emitting device, a lattice constant and a thermal expansion coefficient are group III nitride from the viewpoint of epitaxially growing a high-quality group III nitride semiconductor layer serving as a light emitting layer. A GaN substrate that approximates a physical semiconductor layer is preferably used.

  Since such a GaN substrate is very expensive, in Japanese Unexamined Patent Application Publication No. 2006-210660 (hereinafter referred to as Reference Document 1) and Japanese Unexamined Patent Application Publication No. 2008-300562 (hereinafter referred to as Reference Document 2), a silicon (Si) substrate, A substrate in which a GaN layer having a small film thickness is bonded onto a support substrate other than GaN such as a sapphire substrate and a method for manufacturing the same have been proposed.

JP 2006-210660 A JP 2008-300562 A

  However, even if the bonded substrate proposed in the above Japanese Patent Laid-Open No. 2006-210660 (Cited Document 1) and Japanese Patent Laid-Open No. 2008-300562 (Cited Document 2) is used, a supporting substrate and a GaN layer other than GaN are used. Therefore, it is difficult to epitaxially grow a high-quality group III nitride semiconductor layer on the GaN layer of the bonded substrate.

  Therefore, a method for manufacturing a semiconductor device in which a high-quality semiconductor device is obtained by epitaxial growth of a high-quality semiconductor layer using a bonded substrate of a support substrate and a GaN layer having the same or approximate thermal expansion coefficient as the GaN layer, and An object of the present invention is to provide a laminated support substrate for epitaxial growth and a laminated support substrate for devices which are produced by such a production method.

The manufacturing method of the semiconductor device concerning this invention comprises the process of forming the intermediate | middle layer containing a photothermal conversion layer on Ga containing transparent support substrate, and producing a laminated support substrate. In addition, the method includes a step of manufacturing a laminated substrate by attaching a GaN substrate to an intermediate layer of the laminated supporting substrate. In addition, by separating the GaN substrate of the laminated substrate from the bonding surface with the intermediate layer at a predetermined depth, the laminated support for epitaxial growth in which the GaN layer is formed on the intermediate layer of the laminated support substrate A step of producing a substrate; In addition, the device includes a step of producing a device multilayer support substrate by epitaxially growing at least one transparent semiconductor layer on the GaN layer of the epitaxial growth support substrate. In addition, the laminated support substrate for devices can absorb the light-to-heat conversion layer at a wavelength longer than the wavelength corresponding to the lowest band gap energy among the band gap energies of the Ga-containing transparent support substrate, the GaN layer, and the transparent semiconductor layer. Irradiates light of a wavelength, and the irradiated light is absorbed by the photothermal conversion layer and converted into heat, and the surface in contact with the intermediate layer of the Ga-containing transparent support substrate is decomposed by the heat, and the Ga-containing transparent support substrate and the intermediate layer preparative by are separated, comprising the step of fabricating the stacked wafers for device comprising a transparent semiconductor layer and the GaN layer and the intermediate layer, the intermediate layer containing a light-to-heat conversion layer that have a melting point of at least 1200 ° C.. A step of removing the intermediate layer from the device laminated wafer to produce a semiconductor device including a transparent semiconductor layer laminated wafer including a transparent semiconductor layer and a GaN layer. According to this method, a high-quality semiconductor device having a high-quality semiconductor layer can be obtained.

In the method for producing a semiconductor device according to the present invention, the Ga-containing transparent support substrate and the transparent semiconductor layer have a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm, and the photothermal conversion layer has a wavelength of 500 nm or more. The light absorption coefficient for light of less than 600 nm can be 1 × 10 ³ cm ⁻¹ or more. Thus, by using laser light having a wavelength of 500 nm or more and less than 600 nm to separate the Ga-containing transparent support substrate and the intermediate layer, the Ga-containing transparent support substrate, the GaN layer, and the transparent semiconductor layer are transmitted without being absorbed. While avoiding heat-induced damage due to light absorption, it is possible to separate the Ga-containing transparent support substrate and the intermediate layer by using the energy of light absorbed by the light-to-heat conversion layer as heat, and as a result The transparent support substrate can be easily separated while maintaining a high-quality semiconductor layer.

In the method for manufacturing a semiconductor device according to the present invention, the intermediate layer may further include a first transparent layer disposed between the photothermal conversion layer of the intermediate layer and the GaN substrate. Thereby, atomic diffusion to the GaN layer and the transparent semiconductor layer due to migration of atoms in the photothermal conversion layer can be suppressed. Here, the first transparent layer can have a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm. This reduces damage to the GaN layer and the transparent semiconductor layer during light irradiation, and facilitates selective separation between the intermediate layer and the transparent support substrate.

Moreover, in the manufacturing method of the semiconductor device concerning this invention, an intermediate | middle layer can further contain the 2nd transparent layer arrange | positioned between the photothermal conversion layer of an intermediate | middle layer, and Ga containing transparent support substrate. Thereby, atomic diffusion to the Ga-containing transparent support substrate due to migration of atoms in the photothermal conversion layer can be suppressed, and the bonding strength between the intermediate layer and the Ga-containing transparent support substrate can be increased. Here, the second transparent layer can have a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm. Thereby, the light absorption in a photothermal conversion layer is not inhibited.

  In the method for manufacturing a semiconductor device according to the present invention, the thickness of the second transparent layer can be 0.3 times or more and 2.5 times or less the thickness of the photothermal conversion layer. While preventing the occurrence of peeling at the interface between the photothermal conversion layer and the second transparent layer in the intermediate layer, it is more selective and efficient between the Ga-containing transparent support substrate and the second transparent layer of the intermediate layer. Separation can be ensured.

  In the method for manufacturing a semiconductor device according to the present invention, the thickness of the first transparent layer can be made larger than the thickness of the second transparent layer. Thereby, since the temperature of the bonding surface of the intermediate layer and the Ga-containing transparent support substrate can be made higher than the temperature of the bonding surface of the intermediate layer and the GaN layer, the bonding between the intermediate layer and the GaN layer is possible. Can be selectively separated between the intermediate layer and the Ga-containing transparent support substrate.

In the method for manufacturing a semiconductor device according to the present invention, the light applied to the laminated support substrate for devices can be laser light having a wavelength of 500 nm or more and less than 600 nm. Accordingly, the Ga-containing transparent support substrate and the intermediate layer can be separated without damaging the Ga-containing transparent support substrate, the GaN layer, and the transparent semiconductor layer. Here, the laser beam can be a laser beam based on the second harmonic of the Nd: YAG laser beam or the Nd: YVO ₄ laser beam. Such laser light is extremely effective in separating the Ga-containing transparent support substrate and the intermediate layer without damaging the Ga-containing transparent support substrate, the GaN layer, and the transparent semiconductor layer.

  Further, in the method for manufacturing a semiconductor device according to the present invention, when the laminated support substrate for devices is irradiated with light to separate the Ga-containing transparent support substrate and the intermediate layer, the Ga-containing transparent support substrate is separated from the Ga-containing transparent support substrate. Metal Ga is deposited at the interface between the substrate and the intermediate layer. By using this metal Ga layer, the Ga-containing transparent support substrate and the intermediate layer can be easily separated.

In the method of manufacturing the semiconductor device according to the present invention, an intermediate layer containing a light-to-heat conversion layer since it has a melting point of at least 1 200 ° C., epitaxial growth (usually 800 ° C. C. to 1100 approximately ° C.) and thermal annealing (usually ~ In a high-temperature process such as 700 ° C., the intermediate layer including the photothermal conversion layer can be prevented from being damaged by heat. Here, the photothermal conversion layer of the intermediate layer can be an amorphous silicon layer. The photothermal conversion layer of the intermediate layer is a layer containing at least one selected from the group consisting of molybdenum, tungsten, tantalum, titanium, platinum, palladium, carbon, and silicides thereof and nitrides thereof. Can do. Since these materials have a light absorption coefficient of 1 × 10 ³ cm ⁻¹ or more for light having a wavelength of 500 nm or more and less than 600 nm and a melting point of 1200 ° C. or more, they are suitable as a photothermal conversion layer. The first transparent layer of the intermediate layer can be any one of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer. The second transparent layer of the intermediate layer can be any of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer. Since these layers have a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm and a melting point of 1200 ° C. or more, they are suitable as a transparent layer. The transparent semiconductor layer can be a group III nitride semiconductor layer. Since such a layer has a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm, a high-quality semiconductor device can be obtained without being damaged by irradiation light.

  Moreover, in the method for manufacturing a semiconductor device according to the present invention, ions can be implanted into the surface of the GaN substrate having a predetermined depth from the bonding surface with the intermediate layer. Thereby, it can isolate | separate in the surface embrittled by ion implantation.

  In the method for manufacturing a semiconductor device according to the present invention, the semiconductor device further includes a transparent semiconductor layer laminated wafer supporting substrate for supporting the transparent semiconductor layer laminated wafer, and after the step of producing the device laminated supporting substrate. Before the step of manufacturing the laminated wafer for devices, in the step of bonding the transparent semiconductor layer laminated wafer supporting substrate to the transparent semiconductor layer side of the laminated supporting substrate for devices and the step of producing the semiconductor device, the transparent semiconductor layer laminated wafer Any one of the steps of attaching the transparent semiconductor layer laminated wafer supporting substrate to the substrate may further be provided. Thereby, the mechanical strength of the transparent semiconductor layer laminated wafer can be reinforced during the manufacturing process.

Further, in the method for manufacturing a semiconductor device according to the present invention, the transparent semiconductor layer is a light emitting layer that emits light having a shorter wavelength than the light irradiated to the laminated support substrate for devices and a peak wavelength of 300 nm to 550 nm. In addition, the transparent semiconductor layer laminated wafer supporting substrate may have a light absorption coefficient of less than 1 × 10 ⁴ cm ⁻¹ for light having a wavelength of 300 nm to 550 nm. By using such a transparent semiconductor layer, a high-quality semiconductor device having a peak wavelength in at least one of the ultraviolet, blue, and green wavelength regions can be obtained. Further, by using such a transparent semiconductor layer laminated wafer supporting substrate, a semiconductor device having high light extraction efficiency can be obtained. Here, the transparent semiconductor layer laminated wafer support substrate can include at least one selected from the group consisting of sapphire, spinel, quartz, aluminum nitride, diamond, and glass. Since these materials have a light absorption coefficient of less than 1 × 10 ⁴ cm ⁻¹ for light with a wavelength of 300 nm or more and 550 nm or less, they are suitable as substrates for semiconductor devices.

  In the method for manufacturing a semiconductor device according to the present invention, the transparent semiconductor layer laminated wafer support substrate can have conductivity having a specific resistance of 10 Ωcm or less. By using such a transparent semiconductor layer laminated wafer supporting substrate, the working area of the device can be widened, and a device with high luminance can be obtained. Here, the transparent semiconductor layer laminated wafer support substrate may include at least one selected from the group consisting of silicon, gallium arsenide, indium phosphide, and the first metal. Here, the first metal can be at least one of molybdenum, tungsten, copper, aluminum, and alloys thereof. Since these materials have high conductivity with a specific resistance of 10 Ωcm or less, they are suitable as a transparent semiconductor layer laminated wafer supporting substrate.

Further, in the semiconductor device according to the present invention, the transparent semiconductor layer includes a light emitting layer that emits light having a wavelength shorter than that of light irradiated on the laminated support substrate for devices and having a wavelength of 300 nm or more and 550 nm or less. The semiconductor layer laminated wafer support substrate can have conductivity with a light absorption coefficient of less than 1 × 10 ⁴ cm ⁻¹ for light having a wavelength of 300 nm or more and 550 nm or less and a specific resistance of 10 Ωcm or less. By using such a transparent semiconductor layer, a high-quality semiconductor device having a peak wavelength in at least one of the ultraviolet, blue, and green wavelength regions can be obtained. Further, by using such a transparent semiconductor layer laminated wafer supporting substrate, a semiconductor device having high light extraction efficiency and high conductivity can be obtained. Here, the transparent semiconductor layer laminated wafer supporting substrate can be at least one selected from the group consisting of gallium oxide, silicon carbide, zinc selenide, aluminum nitride, and diamond. Since these materials have high transparency with a light absorption coefficient of less than 1 × 10 ⁴ cm ⁻¹ for light with a wavelength of 300 nm or more and 550 nm or less and high conductivity with a specific resistance of 10 Ωcm or less, a transparent semiconductor layer laminated wafer supporting substrate It is suitable as.

  Further, in the method for manufacturing a semiconductor device according to the present invention, the specific resistance is disposed between the transparent semiconductor layer laminated wafer supporting substrate and the GaN layer or the transparent semiconductor layer, and includes either the second metal or the conductive oxide. Can further include a conductive adhesive layer of 10 Ωcm or less. Thereby, while making the electroconductivity of a semiconductor device high, the adhesiveness between a transparent semiconductor layer laminated wafer support substrate and a GaN layer or a transparent semiconductor layer can be made high. Here, the second metal can be at least one selected from the group consisting of titanium, gold, silver, nickel, aluminum, zinc, germanium, and alloys thereof. Further, the conductive oxide can be at least one selected from the group consisting of zinc oxide, gallium oxide, tin oxide, indium zinc oxide, indium tin oxide, and antimony tin oxide. Since these materials have high conductivity with a specific resistance of 10 Ωcm or less, they are suitable as a conductive adhesive layer.

The laminated support substrate for epitaxial growth according to the present invention includes a Ga-containing transparent support substrate, an intermediate layer disposed on the Ga-containing transparent support substrate, and a GaN layer disposed on the intermediate layer. The layer includes a light-to-heat conversion layer, the intermediate layer including the light-to-heat conversion layer has a melting point of 1200 ° C. or higher, and the wavelength of light that can be absorbed by the light-to-heat conversion layer depends on the Ga-containing transparent support substrate, the GaN layer, and the transparent semiconductor layer. Longer than the wavelength corresponding to the lowest band gap energy among the band gap energies, the light irradiated by the light irradiation is absorbed by the light-to-heat conversion layer and converted to heat, and the heat causes an intermediate of the Ga-containing transparent support substrate. The surface in contact with the layer is decomposed, and the Ga-containing transparent support substrate and the intermediate layer are separated. Such a laminated support substrate for epitaxial growth epitaxially grows at least one high-quality transparent semiconductor on the GaN layer, and separates the Ga-containing transparent support substrate and the intermediate layer, thereby producing a high-quality semiconductor device. be able to. Here, the photothermal conversion layer can be an amorphous silicon layer. The photothermal conversion layer can be a layer containing at least one selected from the group consisting of molybdenum, tungsten, tantalum, titanium, platinum, palladium, carbon, silicides thereof, and nitrides thereof. Since these materials have a light absorption coefficient of 1 × 10 ³ cm ⁻¹ or more for light having a wavelength of 500 nm or more and less than 600 nm and a melting point of 1200 ° C. or more, they are suitable as a photothermal conversion layer.

The intermediate layer can further include a first transparent layer disposed between the photothermal conversion layer of the intermediate layer and the GaN layer. As a result, damage to the GaN layer and the transparent semiconductor layer epitaxially grown thereon can be reduced, and selective separation between the intermediate layer and the transparent support substrate becomes possible. Here, the first transparent layer can be any of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer. Since these layers have a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm and a melting point of 1200 ° C. or more, they are suitable as a transparent layer.

The intermediate layer can further include a second transparent layer disposed between the light-to-heat conversion layer of the intermediate layer and the Ga-containing transparent support substrate. Thereby, the atomic diffusion by the migration of atoms in the photothermal conversion layer and the damage to the Ga-containing transparent support substrate caused thereby can be suppressed, and the bonding strength between the intermediate layer and the Ga-containing transparent support substrate can be increased. Here, the second transparent layer can be any one of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer. Since these layers have a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm and a melting point of 1200 ° C. or more, they are suitable as a transparent layer.

  In the laminated support substrate for epitaxial growth according to the present invention, the thickness of the second transparent layer can be 0.3 to 2.5 times the thickness of the photothermal conversion layer. While preventing the occurrence of peeling at the interface between the photothermal conversion layer and the second transparent layer in the intermediate layer, it is more selective and efficient between the Ga-containing transparent support substrate and the second transparent layer of the intermediate layer. Separation can be ensured.

  Moreover, in the laminated support substrate for epitaxial growth according to the present invention, the thickness of the first transparent layer can be made larger than the thickness of the second transparent layer. Thereby, since the temperature of the bonding surface of the intermediate layer and the Ga-containing transparent support substrate can be made higher than the temperature of the bonding surface of the intermediate layer and the GaN layer, the bonding between the intermediate layer and the GaN layer is possible. Can be selectively separated between the intermediate layer and the Ga-containing transparent support substrate.

The laminated support substrate for a device according to the present invention includes the above-described laminated support substrate for epitaxial growth and at least one transparent semiconductor layer epitaxially grown on the GaN layer of the laminated support substrate for epitaxial growth. Such a laminated support substrate for a device includes at least one transparent semiconductor of good quality epitaxially grown on a GaN layer, and the intermediate photothermal conversion layer is heated to a high temperature by absorbing light and is in contact with the intermediate layer. Since the surface of the containing transparent support substrate is decomposed and separated between the intermediate layer and the Ga containing transparent support substrate, a high-quality semiconductor device can be produced. Here, the transparent semiconductor layer can be a group III nitride semiconductor layer. Since such a layer has a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm, a high-quality semiconductor device can be obtained without being damaged by irradiation light.

  According to the present invention, a semiconductor device manufacturing device that can produce a high-quality semiconductor device by epitaxially growing a high-quality semiconductor layer using a bonded substrate of a support substrate and a GaN layer having the same or approximate thermal expansion coefficient as the GaN layer. Provided are a method, and a laminated support substrate for epi-growth and a laminated support substrate for a device manufactured in such a manufacturing method.

It is a schematic sectional drawing which shows an example of the manufacturing method of the semiconductor device concerning this invention. Here, (A) shows the production process of the laminated support substrate, (B) shows the production process of the laminated substrate, (C) shows the production process of the epitaxial growth laminated support substrate, and (D) shows The manufacturing process of the laminated support substrate for devices is shown, (E) and (F) show the manufacturing process of the laminated wafer for devices, and (G) and (H) are the manufacturing processes of the semiconductor device including the transparent semiconductor layer laminated wafer. Indicates. It is a schematic sectional drawing which shows the other example of the manufacturing method of the semiconductor device concerning this invention. Here, (A) shows a manufacturing process of a laminated support substrate for devices with two electrodes, (B) and (C) show a manufacturing process of a laminated wafer for devices with two electrodes, and (D) shows two electrodes. 2 shows a manufacturing process of the attached transparent semiconductor layer laminated wafer, and (E) and (F) show a manufacturing process of the semiconductor device. It is a schematic sectional drawing which shows the other example of the manufacturing method of the semiconductor device concerning this invention. Here, (A) shows a manufacturing process of a laminated support substrate for a device with one electrode, (B) and (C) show a manufacturing process of a laminated wafer for a device with one electrode, and (D) shows one electrode. 2 shows a manufacturing process of the attached transparent semiconductor layer laminated wafer, and (D), (E), and (F) show a manufacturing process of the semiconductor device. It is a schematic sectional drawing which shows the other example of the manufacturing method of the semiconductor device concerning this invention. Here, (A) shows the bonding process of the transparent semiconductor layer laminated wafer support substrate to the laminated support substrate for devices, (B) and (C) show the production process of the device laminated wafer with the support substrate, (D) shows the manufacturing process of the transparent semiconductor layer laminated wafer with a support substrate, (E) shows the manufacturing process of a semiconductor device. It is a schematic sectional drawing which shows the other example of the manufacturing method of the semiconductor device concerning this invention. Here, (A) and (B) show a manufacturing process of a laminated wafer for devices, (C) shows a manufacturing process of a transparent semiconductor layer laminated wafer, and (D), (E), (F1) and (F2). ) Shows a manufacturing process of a semiconductor device. It is a schematic sectional drawing which shows the other example of the manufacturing method of the semiconductor device concerning this invention. Here, (A) shows the manufacturing process of the laminated support substrate for devices, (B) shows the manufacturing process of the laminated support substrate for devices with one electrode, and (C) and (D) show the manufacturing processes of the semiconductor device. Indicates. It is a schematic sectional drawing which shows the other example of the manufacturing method of the semiconductor device concerning this invention. Here, (A) shows the manufacturing process of the laminated support substrate for devices, (B) shows the manufacturing process of the laminated support substrate for devices with one electrode, and (C) and (D) show the manufacturing processes of the semiconductor device. Indicates. It is a schematic sectional drawing which shows the other example of the manufacturing method of the semiconductor device concerning this invention. Here, (A) shows a manufacturing process of a laminated support substrate for a device, (B) shows a manufacturing process of a laminated support substrate for a device with two electrodes, and (C) shows a manufacturing process of a semiconductor device. It is a schematic sectional drawing which shows the other example of the manufacturing method of the semiconductor device concerning this invention. Here, (A) shows a manufacturing process of a laminated support substrate for a device, (B) shows a manufacturing process of a laminated support substrate for a device with three electrodes, and (C) shows a manufacturing process of a semiconductor device.

[Embodiment 1]
With reference to FIG. 1, the manufacturing method of the semiconductor device which is one embodiment of this invention forms the intermediate | middle layer 20a containing the photothermal conversion layer 21 on the Ga containing transparent support substrate 10, and produces the laminated support substrate 1. FIG. A process is provided (FIG. 1 (A)). In addition, the method includes a step of manufacturing the laminated substrate 2 by attaching the GaN substrate 30 to the intermediate layer 20a of the laminated support substrate 1 (FIG. 1B). The GaN layer 30a was formed on the intermediate layer 20 of the laminated support substrate 1 by separating the GaN substrate 30 of the laminated substrate 2 on the plane P having a predetermined depth from the bonding surface with the intermediate layer 20. A step of producing a laminated support substrate 3 for epi growth is provided (FIG. 1C). In addition, the device includes a step of fabricating the device multilayer support substrate 4 by epitaxially growing at least one transparent semiconductor layer 40 on the GaN layer 30a of the epitaxial growth support substrate 3 (FIG. 1D). Further, the laminated support substrate 4 for devices has a wavelength longer than the wavelength corresponding to the lowest band gap energy among the band gap energies of the Ga-containing transparent support substrate 10, the GaN layer 30a, and the transparent semiconductor layer 40, and a photothermal conversion layer. By irradiating light L having a wavelength that can be absorbed by the Ga-containing transparent support substrate 10 and the intermediate layer 20, the device laminated wafer 5 including the transparent semiconductor layer 40, the GaN layer 30 a, and the intermediate layer 20 is separated. Is provided (FIGS. 1E and 1F). In addition, the method includes a step of fabricating a semiconductor device 7 including a transparent semiconductor layer laminated wafer 6 including a transparent semiconductor layer 40 and a GaN layer 30a by removing the intermediate layer from the device laminated wafer 5 (FIG. 1 (G) and ( H)). By providing these steps, the transparent semiconductor layer laminated wafer 6 can be formed without damaging the GaN layer 30a and the transparent semiconductor layer 40, so that a high-quality semiconductor device having a high-quality semiconductor layer can be obtained. .

(Lamination support substrate manufacturing process)
With reference to FIG. 1 (A), the manufacturing process of the lamination | stacking support substrate 1 is performed by forming the intermediate | middle layer 20a containing the photothermal conversion layer 21 on the Ga containing transparent support substrate 10. FIG. As will be described later, in the laminated support substrate 1 obtained by this step, heat is stored in the intermediate layer 20a including the light-to-heat conversion layer 21 by the light irradiated to the substrate being absorbed by the light-to-heat conversion layer 21. The surface that contacts the intermediate layer 20a of the Ga-containing transparent support substrate 10 is decomposed by this heat, and the intermediate layer 20a and the Ga-containing transparent support substrate 10 can be separated.

  The method for forming the intermediate layer 20a on the Ga-containing transparent support substrate 10 is not particularly limited, and a plasma CVD (chemical vapor deposition) method, a sputtering method, a vacuum evaporation method, or the like is used.

The intermediate layer 20a including the photothermal conversion layer 21 is at a high temperature as described above. Further, when the transparent semiconductor layer 40 is epitaxially grown, it is exposed to a high temperature of 800 ° C. or higher, and in some cases, near 1100 ° C. For these reasons, the intermediate layer 20a including the photothermal conversion layer 21 preferably has high heat resistance, and preferably has a melting point of, for example, 1200 ° C. or higher. Further, as will be described later, the intermediate layer 20a further includes a transparent layer (for example, the first transparent layer 23a and the second transparent layer 25 in FIG. 1A) on one side or both sides of the photothermal conversion layer 21. be able to. For example, the intermediate layer 20a includes a second transparent layer 25, a photothermal conversion layer 21, and a first transparent layer 23a in this order from the Ga-containing transparent support substrate 10 side. The first transparent layer 23a is bonded to the GaN substrate 30 in a later step (FIG. 1B) and is positioned between the GaN substrate 30 and the photothermal conversion layer 21 as the first transparent layer 23. become. Such transparent layers (for example, the first transparent layer 23 and the second transparent layer 25) have a light absorption coefficient of 1 × 10 ³ cm ⁻¹ or more for light having a wavelength of 500 nm or more and less than 600 nm, as will be described later. For example, any one of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer is preferable. As will be described later, the photothermal conversion layer 21 preferably has a light absorption coefficient of 1 × 10 ³ cm ⁻¹ or more for light having a wavelength of 500 nm or more and less than 600 nm. For example, an amorphous silicon layer, molybdenum, tungsten, or tantalum. And a layer containing at least one selected from the group consisting of titanium, platinum, palladium, carbon, silicides thereof, and nitrides thereof.

As will be described later, the Ga-containing transparent support substrate 10 preferably has a light absorption coefficient for light having a wavelength of 500 nm or more and less than 600 nm of less than 1 × 10 ³ cm ⁻¹ or more, for example, a GaN support substrate. .

(Manufacturing process of laminated substrate)
With reference to FIG. 1B, the manufacturing process of the laminated laminated substrate 2 is performed by bonding a GaN substrate 30 to the intermediate layer 20 a of the laminated supporting substrate 1. Here, the method of bonding the GaN substrate 30 to the intermediate layer 20a of the laminated support substrate 1 is not particularly limited, and the surfaces of the bonding surfaces are cleaned and bonded directly, and then heated to 700 ° C to 1000 ° C. Direct bonding method that joins together, metal film is formed, alloy bonding method that joins the metal of the metal film by alloying by raising the temperature while making contact, activated the bonding surface with plasma or ions, etc. The surface activation method is preferably used.

  In addition, the bonded surface of the GaN substrate 30 is formed with an outermost layer of the intermediate layer 20a of the laminated support substrate 1 from the viewpoint of reducing heat transmitted from the photothermal conversion layer to the GaN substrate 30 when the light L is irradiated and increasing bonding strength. It is preferable that layers of the same material are formed chemically. For example, when the outermost layer of the intermediate layer 20a of the laminated support substrate 1 is the first transparent layer 23a, the first transparent layer 23b that is a layer of the same material as the first transparent layer 23a is used. Is preferably formed on the bonding surface of the GaN substrate 30. The first transparent layer 23 b of the GaN substrate 30 is bonded to the first transparent layer 23 a of the intermediate layer 20 a of the laminated support substrate 1, so that the first transparent layer is interposed between the photothermal conversion layer 21 and the GaN substrate 30. 23 is formed. Thus, the photothermal conversion layer 21, the first transparent layer 23 arranged between the photothermal conversion layer 21 and the GaN substrate 30, and the first transparent layer 23 arranged between the photothermal conversion layer 21 and the Ga-containing transparent support substrate 10. An intermediate layer 20 including two transparent layers 25 is formed.

(Manufacturing process of laminated support substrate for epi growth)
Referring to FIG. 1C, in the process of manufacturing the epitaxial growth laminated support substrate 3, the GaN substrate 30 of the laminated laminated substrate 2 is placed on the surface P having a predetermined depth from the bonded surface with the intermediate layer 20. This is done by separating. Through this step, the epitaxial growth laminated support substrate 3 in which the GaN layer 30a is formed on the intermediate layer 20 of the laminated support substrate 1 is obtained.

  The method for separating the GaN substrate 30 from the bonding surface with the intermediate layer 20 on the surface P having a predetermined depth is not particularly limited, and a method for cutting the GaN substrate 30 on the surface P, the laminated support substrate 1 or the like. In order to form a fragile region, the GaN substrate 30 into which ions have been implanted into the surface P before being bonded to the laminated support substrate 1 is bonded to the stacked support substrate 1, and then heat and / or stress is applied to the ions. A method of separating on the surface P embrittled by implantation is used. By such a method, the GaN layer 30a having a thickness of 0.05 μm to 100 μm can be formed on the intermediate layer 20 of the laminated support substrate 1.

  Here, the Ga-containing transparent support substrate 10 has a thermal expansion coefficient that is the same as or close to the thermal expansion coefficient of the GaN layer 30a from the viewpoint of not generating cracks in the GaN layer 30a during epitaxial growth or annealing. A GaN support substrate having a main surface having the same plane orientation as that of the main surface of the GaN layer 30a is particularly preferable.

(Manufacturing process of laminated support substrate for devices)
Referring to FIG. 1D, the process for manufacturing the device multilayer support substrate 4 is performed by epitaxially growing at least one transparent semiconductor layer 40 on the GaN layer 30 a of the epitaxial growth support substrate 3.

  Here, by using the GaN-containing transparent support substrate 10 whose thermal expansion coefficient is the same as or close to the thermal expansion coefficient of the GaN layer 30a, at least one layer having high quality without causing cracks during epitaxial growth or annealing treatment. The transparent semiconductor layer 40 can be formed. From this point of view, the Ga-containing transparent support substrate 10 is preferably a GaN support substrate having a main surface with the same plane orientation as that of the main surface of the GaN layer 30a, for example.

  The method for epitaxially growing at least one transparent semiconductor layer 40 on the GaN layer 30a of the epitaxial growth laminated support substrate 3 is not particularly limited, but from the viewpoint of growing a high-quality transparent semiconductor layer, MOCVD (organometallic) A vapor phase method such as a chemical vapor deposition method, an MBE (molecular beam epitaxy) method or an HVPE (hydride vapor phase epitaxy) method is preferably used.

At least one transparent semiconductor layer 40 epitaxially grown on the epitaxial growth laminated support substrate 3 has the same lattice constant as that of the GaN layer 30a from the viewpoint of growing a high-quality transparent semiconductor layer 40 without generating cracks or the like. It is preferable that the thermal expansion coefficients are the same as or similar to those of the GaN layer 30a and the Ga-containing transparent support substrate 10. The transparent semiconductor layer 40 preferably has a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm, as will be described later. Further, from the viewpoint of not absorbing the irradiation light transmitted through the intermediate layer, the transparent semiconductor layer 40 is light having a shorter wavelength than the light irradiated to the laminated support substrate 4 for devices and a peak wavelength of not less than 300 nm and not more than 550 nm. It is preferable to include a light emitting layer 45 that emits. From these viewpoints, the transparent semiconductor layer 40 is preferably a group III nitride semiconductor layer, for example.

(Process for producing laminated wafers for devices)
Referring to FIGS. 1E and 1F, the device laminated wafer 5 is manufactured in such a manner that the device laminated support substrate 4 has a band gap between the Ga-containing transparent support substrate 10, the GaN layer 30a, and the transparent semiconductor layer 40. Irradiating light L having a wavelength longer than the wavelength corresponding to the lowest bandgap energy among the energies and capable of being absorbed by the photothermal conversion layer, thereby separating the Ga-containing transparent support substrate 10 and the intermediate layer 20 from each other. Is done. Through this process, the device laminated wafer 5 including the transparent semiconductor layer 40, the GaN layer 30a, and the intermediate layer 20 is obtained. Here, FIG. 1 (E) shows a case where light L is irradiated from the Ga-containing transparent support substrate 10 side of the device multilayer support substrate 4, but the transparent semiconductor layer of the device multilayer support substrate 4. The light L may be irradiated from the 40 side.

  In this step, the energy per photon of light irradiated on the device multilayer support substrate 4 is the lowest band gap energy among the band gap energies of the Ga-containing transparent support substrate 10, the GaN layer 30a, and the transparent semiconductor layer 40. Since it is lower than energy, light is not absorbed by the Ga-containing transparent support substrate 10, the GaN layer 30a, and the transparent semiconductor layer 40, but is transmitted. Thereby, in the Ga containing transparent support substrate 10, the GaN layer 30a, and the transparent semiconductor layer 40, damage caused by heat generated due to unnecessary light absorption can be avoided.

  The light irradiated to the device multilayer support substrate 4 is absorbed by the photothermal conversion layer 21 and converted into heat. With this heat, the surface of the Ga-containing transparent support substrate 10 that contacts the intermediate layer 20 is decomposed, and the laminated support substrate 4 for devices is separated between the Ga-containing transparent support substrate 10 and the intermediate layer 20. Thus, the device laminated wafer 5 including the transparent semiconductor layer 40, the GaN layer 30a, and the intermediate layer 20 is obtained.

The light irradiated to the device multilayer support substrate 4 has a wavelength longer than the wavelength corresponding to the lowest band gap energy among the band gap energies of the Ga-containing transparent support substrate 10, the GaN layer 30a, and the transparent semiconductor layer 40. Although there is no particular limitation, in order to efficiently separate the Ga-containing transparent support substrate 10 and the intermediate layer 20 with relatively low input energy, laser light with a wavelength of 500 nm or more and less than 600 nm is preferable, for example, a wavelength of 808 nm. Nd: YAG laser light having a wavelength of 1064 nm excited by the semiconductor laser (where Nd: YAG is formed of Y (yttrium), A (aluminum), G (garnet) added with Nd (neodymium) Crystal)) or Nd: YVO ₄ laser light (where Nd: YVO ₄ is Nd (Neodymium) added Y (yttrium) · V (vanadium) · O ₄ (oxide) or Y (yttrium) · VO ₄ (vanadate)))) is called so-called LiB ₃ O ₅ A laser beam having a wavelength of 532 nm converted by an SHG (Second Harmonic Generation) crystal is preferably used. The light having this wavelength can constitute the Ga-containing transparent support substrate 10, the GaN layer 30 a and the transparent semiconductor layer 40, for example, a group III nitride such as GaN, InGaN, AlGaN, or the first and second transparent layers 23. 25 can be absorbed by any one of silicon dioxide, silicon nitride, and silicon oxynitride, but is preferably absorbed by, for example, amorphous silicon that can form the photothermal conversion layer 21.

Here, when a GaN support substrate is used as the Ga-containing transparent support substrate 10, the surface in contact with the intermediate layer in the GaN support substrate is decomposed into metal Ga and nitrogen (N ₂ ) gas by irradiation with the light L, and the GaN support is supported. Metal Ga is deposited between the substrate and the intermediate layer. Since metallic Ga melts at 29.8 ° C., the GaN support substrate and the intermediate layer are separated by heating to a temperature higher than this temperature.

In the laminated support substrate 4 for devices, from the viewpoint of forming a high-quality transparent semiconductor layer 40 on the GaN layer 30a, the Ga-containing transparent support substrate 10 is a GaN support substrate, and the transparent semiconductor layer 40 is a group III nitride semiconductor. A layer is preferred. In such a case, the GaN layer 30a, the GaN support substrate (Ga-containing transparent support substrate 10), and the group III nitride semiconductor layer (transparent semiconductor layer 40) usually have a light absorption coefficient of 1 × for light with a wavelength of 500 nm or more and less than 600 nm. Less than 10 ³ cm ⁻¹ . Therefore, for the separation of the GaN support substrate and the intermediate layer, the light irradiated to the laminated support substrate 4 for devices is the GaN layer 30a, the GaN support substrate (Ga-containing transparent support substrate 10), and the group III nitride semiconductor layer. From the viewpoint of reducing damage to the (transparent semiconductor layer 40), it is preferably a laser beam having a wavelength of 500 nm or more and less than 600 nm.

The intermediate layer 20 becomes a high temperature during the separation between the Ga-containing transparent support substrate 10 and the intermediate layer 20. Further, when the transparent semiconductor layer 40 is epitaxially grown, it is exposed to a high temperature of 800 ° C. or higher, and in some cases, near 1100 ° C. For these reasons, the intermediate layer 20 preferably has high heat resistance, for example, preferably has a melting point of 1200 ° C. or higher. That is, the photothermal conversion layer 21 preferably has high heat resistance, and preferably has a melting point of 1200 ° C. or higher, for example. Moreover, when the light irradiated to the laminated support substrate 4 for devices is a laser beam having a wavelength of 500 nm or more and less than 600 nm, the photothermal conversion layer 21 preferably absorbs light in the wavelength region efficiently, so that the wavelength of 500 nm. The light absorption coefficient for light of less than 600 nm is preferably 1 × 10 ³ cm ⁻¹ or more. As a layer made of a material that satisfies the above requirements, the photothermal conversion layer 21 is preferably, for example, an amorphous silicon layer.

  In the device multilayer support substrate 4, the intermediate layer 20 including the photothermal conversion layer 21 is in contact with the Ga-containing transparent support substrate 10 and the GaN layer 30 a. For this reason, when the photothermal conversion layer 21 is heated to a high temperature by irradiation with the light L described above, the heat is in contact with not only the Ga-containing transparent support substrate 10 but also the GaN layer 30a and the GaN layer 30a. 40 and may damage the GaN layer 30a and the transparent semiconductor layer 40. Such damage to the GaN layer 30a and the transparent semiconductor layer 40 is reduced, and the intermediate layer 20 and the Ga-containing transparent support substrate 10 are reliably separated while maintaining the bonding between the intermediate layer 20 and the GaN layer 30a. Therefore, it is preferable that the intermediate layer 20 further includes a first transparent layer 23 disposed between the photothermal conversion layer 21 of the intermediate layer 20 and the GaN layer 30a. Further, the first transparent layer 23 is formed by diffusing atoms into the GaN layer 30a and the transparent semiconductor layer 40 due to migration of atoms in the photothermal conversion layer 21 (for example, Si atoms in the amorphous silicon layer), and a GaN layer during light irradiation. The damage given to 30a and the transparent semiconductor layer 40 is reduced and the bonding strength between the intermediate layer 20 and the GaN layer 30a is also increased.

The first transparent layer 23 is not particularly limited, in order not to cause thermal damage to the GaN layer 30a and the transparent semiconductor layer 40 due to heat generation accompanying unnecessary light absorption and / or stress damage due to expansion due to heat. The transparency similar to that of the Ga-containing transparent support substrate 10, the GaN layer 30a, and the transparent semiconductor layer 40, that is, the light absorption coefficient for light having a wavelength of 500 nm to 600 nm is preferably less than 1 × 10 ³ cm ⁻¹ . Further, the first transparent layer 23 is in contact with the photothermal conversion layer 21 that is at a high temperature as described above. Further, when the transparent semiconductor layer 40 is epitaxially grown, it is exposed to a high temperature of 800 ° C. or higher, and in some cases, near 1100 ° C. For these reasons, the first transparent layer 23 preferably has high heat resistance, for example, preferably has a melting point of 1200 ° C. or higher. As a material that satisfies the above requirements, the first transparent layer is particularly preferably, for example, any one of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer.

  Further, from the viewpoint of suppressing atomic diffusion due to migration of atoms in the photothermal conversion layer 21 (for example, Si atoms in the amorphous silicon layer) and increasing the bonding strength between the intermediate layer 20 and the Ga-containing transparent support substrate 10, the intermediate layer 20. Preferably further includes a second transparent layer 25 disposed between the photothermal conversion layer 21 of the intermediate layer 20 and the Ga-containing transparent support substrate 10.

The second transparent layer 25 is not particularly limited, but it does not cause thermal damage to the GaN layer 30a and the transparent semiconductor layer 40 due to heat generation accompanying unnecessary light absorption and / or stress damage due to expansion due to heat. The transparency similar to that of the Ga-containing transparent support substrate 10, the GaN layer 30a, and the transparent semiconductor layer 40, that is, the light absorption coefficient for light having a wavelength of 500 nm to 600 nm is preferably less than 1 × 10 ³ cm ⁻¹ . Further, the second transparent layer 25 is in contact with the photothermal conversion layer 21 that is at a high temperature as described above. Further, when the transparent semiconductor layer 40 is epitaxially grown, it is exposed to a high temperature of 800 ° C. or higher, and in some cases, near 1100 ° C. For these reasons, the second transparent layer 25 preferably has high heat resistance, for example, preferably has a melting point of 1200 ° C. or higher. As a material that satisfies the above requirements, the second transparent layer is particularly preferably, for example, any one of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer.

  When both the first transparent layer 23 and the second transparent layer 25 are present, the thickness of the first transparent layer 23 is preferably larger than the thickness of the second transparent layer 25. Thereby, the temperature of the bonding surface of the intermediate layer 20 and the Ga-containing Ga-containing transparent support substrate 10 can be made higher than the temperature of the bonding surface of the intermediate layer 20 and the GaN layer 30a. By utilizing this, the temperature of the bonding surface between the intermediate layer 20 and the Ga-containing transparent support substrate 10 is set to be higher than the temperature at which the metal Ga can be formed, and the temperature of the bonding surface between the intermediate layer 20 and the GaN layer 30a is set to the metal. By making the temperature lower than the temperature at which Ga can be formed, metal Ga is not formed on the bonding surface of the intermediate layer 20 and the GaN layer 30a, but only on the bonding surface of the intermediate layer 20 and the Ga-containing transparent support substrate 10. Metal Ga60 can be formed. Thus, the device laminated wafer 5 can be formed by selective separation of the bonding surfaces of the intermediate layer 20 of the device laminated support substrate 4 and the Ga-containing transparent support substrate 10.

  In addition, the thickness of the second transparent layer 25 is not particularly limited, but ensures good adhesion between the photothermal conversion layer 21 and the second transparent layer 25 in the intermediate layer 20, and a Ga-containing transparent support substrate. 10 and the second transparent layer 25 of the intermediate layer 20 from the viewpoint of ensuring selective and efficient separation, the thickness of the second transparent layer 25 is set to 0.3 of the thickness of the photothermal conversion layer 21. It is particularly preferable to set it to be not less than twice and not more than 2.5.

  In this way, the device laminated wafer 5 including the transparent semiconductor layer 40 and the GaN layer 30a is obtained. Here, the device laminated wafer 5 has, on the surface of the intermediate layer 20, a metal Ga 60 formed at the interface between the Ga-containing transparent support substrate 10 and the intermediate layer 20 when the Ga-containing transparent support substrate 10 is separated.

  Note that the device laminated wafer 5 obtained in this step and the transparent semiconductor layer laminated wafer 6 (referred to as a laminated wafer of the GaN layer 30a and the transparent semiconductor layer 40) obtained in the next step have extremely low mechanical strength. . For this reason, in order to reinforce the mechanical strength of the resulting device laminated wafer 5 and transparent semiconductor layer laminated wafer 6, the mechanical strength of the transparent semiconductor layer laminated wafer 6 of the device laminated support substrate 4 is reinforced before this step. Therefore, it is preferable to bond a temporary support base material or a transparent semiconductor layer laminated wafer support substrate together.

  For example, referring to FIG. 1E, the temporary support base material 50 can be bonded to the outermost layer of the transparent semiconductor layer 40 of the laminated support substrate 4 for devices with an adhesive 51 interposed. Although there is no restriction | limiting in particular in the temporary support base material 50, From a viewpoint of absorbing the irradiation light which permeate | transmitted the photothermal conversion layer 21 at the time of irradiation of the light L, and generating an unnecessary heat | fever, a sapphire substrate etc. are used preferably. . The adhesive 51 is not particularly limited, but absorbs the irradiation light transmitted through the light-to-heat conversion layer 21 when irradiated with the light L, does not generate unnecessary heat, and is not decomposed. From the viewpoint of easy separation of the substrate 50 from the device laminated wafer 5, Waferbond HT-10, 10 manufactured by Brewer Science, Inc. is preferably used.

  In the temporary support base material 50 described above, the Ga-containing transparent support substrate 10 is separated from the device multilayer support substrate 4 to form the device multilayer wafer 5 in a later step (FIGS. 1E and 1F). Then, the metal Ga 60 and the intermediate layer 20 are separated and removed from the device laminated wafer 5 to form the transparent semiconductor layer laminated wafer 6 (FIG. 1G), and then the transparent semiconductor layer is formed on the GaN layer 30a of the transparent semiconductor layer laminated wafer 6. After the layer laminated wafer support substrate 70 is bonded and the transparent semiconductor layer 40 is supported mechanically, it is removed (FIG. 1 (H)).

  Also, referring to FIG. 4A, before this step, instead of the temporary support substrate, the transparent semiconductor layer laminated wafer support substrate 70 is bonded to the transparent semiconductor layer 40 of the device multilayer support substrate 4. be able to. In such a case, in a subsequent process, the Ga-containing transparent support substrate 10 is separated from the device support multilayer substrate 4C to which the transparent semiconductor layer laminate wafer support substrate 70 is bonded to form a device multilayer wafer 5C with a support substrate. Then, the metal Ga 60 and the intermediate layer 20 are separated and removed from the device laminated wafer 5C with a support substrate to form a transparent semiconductor layer laminated wafer 6C with a support substrate (FIG. 4B and FIG. 4C) (FIG. 4B and FIG. 4C). 4 (D)), and then electrodes and the like are formed on the transparent semiconductor layer laminated wafer 6C with a supporting substrate to obtain the semiconductor device 7 (FIG. 4E). That is, instead of the temporary support substrate, when the transparent semiconductor layer laminated wafer support substrate is bonded to the transparent semiconductor layer of the device multilayer support substrate, a step of bonding the temporary support substrate and a step of removing it are required. do not do.

(Transparent semiconductor layer laminated wafer manufacturing process)
Referring to FIG. 1G, the manufacturing process of the transparent semiconductor layer laminated wafer 6 is performed by removing the intermediate layer 20 from the device laminated wafer 5. Through this process, the transparent semiconductor layer laminated wafer 6 including the transparent semiconductor layer 40 and the GaN layer 30a is obtained. The method for removing the intermediate layer 20 from the device laminated wafer 5 is not particularly limited, and methods such as wet etching and dry etching generally used in semiconductor processes can be used.

(Semiconductor device fabrication process)
Referring to FIG. 1H, the manufacturing process of the semiconductor device 7 is performed by bonding a transparent semiconductor layer laminated wafer support substrate 70 to the transparent semiconductor layer laminated wafer 6. Through this process, the semiconductor device 7 is obtained.

  The method for bonding the transparent semiconductor layer laminated wafer support substrate 70 to the transparent semiconductor layer laminated wafer 6 is not particularly limited, and the surfaces of the surfaces to be bonded are washed and directly bonded, and then heated to 700 ° C. to 1000 ° C. For example, a direct bonding method by bonding and a surface activation method by activating and bonding the bonding surface with plasma or ions are preferably used.

Here, with reference to FIGS. 2 (E) to 2 (F) and FIGS. 3 (E) to (G), in the present semiconductor device 7, the transparent semiconductor layer 40 has light having a peak wavelength of not less than 300 nm and not more than 550 nm. In the case where the light emitting layer 45 that emits light is included, the transparent semiconductor layer laminated wafer supporting substrate preferably has a light absorption coefficient of less than 1 × 10 ⁴ cm ⁻¹ for light having a wavelength of 300 nm to 550 nm. As a result, it is possible to produce a semiconductor optical device with reduced internal absorption and high light extraction efficiency. From this viewpoint, the transparent semiconductor layer laminated wafer support substrate 70 preferably includes at least one selected from the group consisting of sapphire, spinel, quartz, aluminum nitride, diamond, and glass.

  3 (E) to (G) and FIGS. 4 (A) to (E), in the present semiconductor device 7, a transparent semiconductor layer stack is formed for the purpose of providing the device with conductivity in the stacking direction. Wafer support substrate 70 preferably has conductivity having a specific resistance of 10 Ωcm or less. If the device can be provided with conductivity in the stacking direction, the semiconductor device 7 can form a p-electrode 80 and an n-electrode 90 on both main surfaces thereof as shown in FIG. 3G, for example. This eliminates the need to remove a part of the transparent semiconductor layer 40 as compared with the case where both electrodes must be formed on one main surface (see, for example, FIG. 2F), so that a larger area can be obtained. Therefore, a device with higher luminance can be realized. The material constituting the transparent semiconductor layer laminated wafer support substrate 70 preferably includes, for example, at least one selected from the group consisting of silicon, gallium arsenide, indium phosphide, and the first metal. Here, the first metal is not particularly limited as long as the first metal has conductivity of 10 Ωcm or less. For example, molybdenum, tungsten, copper, aluminum, or the like is preferably used.

  3 (E) to 3 (G) and FIGS. 4 (A) to 4 (E), in this semiconductor device 7, the conductivity of the device is increased and the transparent semiconductor layer laminated wafer supporting substrate 70 and From the viewpoint of increasing the adhesion between the GaN layer 30a (not shown) or the transparent semiconductor layer 40, the transparent semiconductor layer laminated wafer support substrate 70 is disposed between the transparent semiconductor layer 40 and the second metal and It is preferable to further include conductive adhesive layers 85, 85a, 85b, 95, 95a, and 95b each having a specific resistance of 10 Ωcm or less including any of the conductive oxides. Here, the second metal is not particularly limited, but from the above viewpoint, for example, it may be at least one selected from the group consisting of titanium, gold, silver, nickel, aluminum, zinc, germanium, and alloys thereof. preferable. The conductive oxide is preferably at least one selected from the group consisting of zinc oxide, gallium oxide, tin oxide, indium zinc oxide, indium tin oxide, and antimony tin oxide.

3E to 3G, in the semiconductor device 7, when the transparent semiconductor layer 40 includes a light emitting layer 45 that emits light having a peak wavelength of 300 nm to 550 nm, The transparent semiconductor layer laminated wafer supporting substrate preferably has a light absorption coefficient of less than 1 × 10 ⁴ cm ⁻¹ for light having a wavelength of 300 nm or more and 550 nm or less. As a result, it is possible to produce a semiconductor optical device with reduced internal absorption and high light extraction efficiency. For the purpose of providing the device with conductivity in the stacking direction, the transparent semiconductor layer laminated wafer support substrate 70 preferably has conductivity with a specific resistance of 10 Ωcm or less. If the device can be provided with conductivity in the stacking direction, the semiconductor device 7 can form a p-electrode 80 and an n-electrode 90 on both main surfaces thereof as shown in FIG. 3G, for example. This eliminates the need to remove a part of the transparent semiconductor layer 40 as compared with the case where both electrodes must be formed on one main surface (see, for example, FIG. 2F), so that a larger area can be obtained. Therefore, a device with higher luminance can be realized. The material constituting the transparent semiconductor layer laminated wafer support substrate 70 preferably includes, for example, at least one selected from the group consisting of gallium oxide, silicon carbide, zinc selenide, aluminum nitride, and diamond.

[Embodiment 2]
Referring to FIG. 1, an epitaxial growth support substrate 3 according to another embodiment of the present invention includes a Ga-containing transparent support substrate 10 and an intermediate layer 20 disposed on the Ga-containing transparent support substrate 10. , A GaN layer 30 a disposed on the intermediate layer 20, and the intermediate layer 20 includes a photothermal conversion layer 21. As described in the first embodiment, the laminated support substrate 3 for epitaxial growth according to the present embodiment can epitaxially grow at least one transparent semiconductor layer 40 of good quality without generating cracks or the like on the GaN layer 30a. it can. In addition, the epitaxial growth support substrate 3 is heated to a high temperature by absorbing the light L irradiated by the photothermal conversion layer 21 of the intermediate layer 20, and the Ga-containing transparent support substrate 10 in contact with the intermediate layer 20 by this high heat. It can be separated between the intermediate layer 20 and the Ga-containing transparent support substrate 10 by utilizing the fact that the surface is decomposed.

  Further, as described in the first embodiment, in the laminated support substrate 3 for epitaxial growth, the intermediate layer 20 is a first transparent layer disposed between the photothermal conversion layer 21 of the intermediate layer 20 and the GaN layer 30a. It is preferable that 23 is further included. Furthermore, it is preferable that the intermediate layer 20 further includes a second transparent layer 25 disposed between the photothermal conversion layer 21 of the intermediate layer 20 and the Ga-containing transparent support substrate 10. Here, the thickness of the first transparent layer 23 is preferably larger than the thickness of the second transparent layer 25. The photothermal conversion layer 21 of the intermediate layer 20 is an amorphous silicon layer or at least one selected from the group consisting of molybdenum, tungsten, tantalum, titanium, platinum, palladium, carbon, and silicides thereof and nitrides thereof. It is preferable that it is a layer containing. The first transparent layer 23 of the intermediate layer 20 is preferably any one of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer. The second transparent layer 25 of the intermediate layer 20 is preferably any one of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer.

  1A to 1C, as described in the first embodiment, the epitaxial growth support substrate 3 is, for example, a manufacturing process of the stack support substrate 1 (FIG. 1A). ), A process for producing the laminated substrate 2 (FIG. 1B) and a process for producing the epitaxial growth laminated support substrate 3 (FIG. 1C).

[Embodiment 3]
Referring to FIGS. 1A to 1D, a device multilayer support substrate 4 which is still another embodiment of the present invention includes an epitaxial growth support substrate 3 described in Embodiment 2, and an epitaxial growth substrate. And at least one transparent semiconductor layer 40 epitaxially grown on the GaN layer 30a of the laminated support substrate 3. The laminated support substrate 4 for this device is heated to a high temperature by absorbing the light L irradiated by the photothermal conversion layer 21 of the intermediate layer 20, and the surface of the Ga-containing transparent support substrate 10 that is in contact with the intermediate layer 20 due to this high heat It can be separated between the intermediate layer 20 and the Ga-containing transparent support substrate 10 by utilizing decomposition. As described in Embodiment 1, the transparent semiconductor layer of the multilayer support substrate 4 for a device is preferably a group III nitride semiconductor layer.

  1A to 1D, as described in the first embodiment, the laminated support substrate 4 for a device includes a manufacturing process of the laminated support substrate 1 (FIG. 1A), It can be manufactured by the manufacturing process of the bonded substrate 2 (FIG. 1B), the manufacturing process of the epitaxial growth laminated support substrate 3 (FIG. 1C), and the manufacturing process of the device laminated support substrate 4.

Example 1
1. Production of Laminated Support Substrate With reference to FIG. 1A, a GaN support substrate having a diameter of 2 inches (5.08 cm) and a thickness of 500 μm was prepared as a Ga-containing transparent support substrate 10 by the HVPE method. Such a GaN support substrate had a Ga atom surface with one main surface being a (0001) plane, an N atom surface with another main surface being a (000-1) plane, and both main surfaces were mirror-finished.

On the Ga atom surface of this GaN support substrate (Ga-containing transparent support substrate 10), as the intermediate layer 20, a silicon dioxide layer (second transparent layer 25) having a thickness of 10 nm and amorphous silicon having a thickness of 60 nm are formed by plasma CVD. A layer (photothermal conversion layer 21) and a silicon dioxide layer (first transparent layer 23a) having a thickness of 130 nm were sequentially deposited to obtain a laminated support substrate 1. The plasma CVD conditions are as follows. In the deposition of the first and second silicon dioxide layers, the flow rate of SiH ₄ gas diluted to 8% by volume with RF of 50 W and Ar gas is 50 sccm (1 sccm is converted to the standard state) 1 cm ³ of gas refers to the amount flowing), N ₂ O gas flow rate per minute Te is 460Sccm, a chamber pressure 80 Pa, a stage temperature of 250 ° C., in the deposition of amorphous silicon layers, RF is 50 W, Ar gas The flow rate of SiH ₄ gas diluted to 8% by volume was 200 sccm, the chamber pressure was 80 Pa, and the stage temperature was 250 ° C.

Further, as a GaN substrate 30 for forming the GaN layer 30a, a GaN substrate having a diameter of 2 inches (5.08 cm) and a thickness of 500 μm formed by the HVPE method was prepared. The GaN substrate 30 has a Ga atom surface whose one main surface is a (0001) plane, an N atom surface whose other main surface is a (000-1) plane, and both main surfaces are mirror-finished. First, a silicon dioxide layer (first transparent layer 23b) having a thickness of 100 nm was deposited on the surface of N atoms of the GaN substrate 30 by plasma CVD. The plasma CVD conditions for depositing this silicon dioxide layer are as follows: RF is 50 W, the flow rate of SiH ₄ gas diluted to 8% by volume with Ar gas is 50 sccm, the N ₂ O gas flow rate is 460 sccm, the chamber pressure is 80 Pa, and the stage temperature. Was 250 ° C. Next, hydrogen ions were implanted from the silicon dioxide layer (first transparent layer 23 b) side of the GaN substrate 30. The hydrogen ion implantation conditions were an acceleration voltage of 50 keV and a dose of 7 × 10 ¹⁷ cm ⁻² . Thus, the GaN substrate 30 implanted with hydrogen ions had a dose peak on the plane P having a depth of about 200 nm from the N atom surface. This dose was measured by performing SIMS (secondary ion mass spectrometer) analysis in the depth direction from the ion implantation side of the GaN substrate ion-implanted in the same batch as a reference.

Adhesion between the GaN support substrate (Ga-containing transparent support substrate 10) and the silicon dioxide layer (second transparent layer 25) of the laminated support substrate 1 obtained above and the GaN substrate 30 and the silicon dioxide layer (in the GaN substrate 30) In order to improve the adhesion with the first transparent layer 23b), annealing was performed in a nitrogen atmosphere at 700 ° C. to 1000 ° C. for 10 minutes, and then the main surfaces of the silicon dioxide layers of both substrates were washed. Specifically, the main surface of silicon dioxide was cleaned by putting both substrates into a dry etching apparatus and exposing them to plasma using oxygen (O ₂ ) gas as a raw material. The plasma conditions at this time were RF of 100 W, O ₂ gas flow rate of 50 sccm, and chamber pressure of 6.7 Pa.

2. Next, referring to FIG. 1B, the laminated substrate 1 was deposited on the silicon dioxide layer (first transparent layer 23a) of the intermediate layer 20 of the laminated support substrate 1 and the GaN substrate 30. The silicon dioxide layer (first transparent layer 23 b), the crystal orientation of one main surface ((0001) plane) of the GaN support substrate (Ga-containing transparent support substrate 10) of the laminated support substrate 1, and one main GaN substrate 30 By superimposing the crystal orientations of the surfaces ((0001) plane) to coincide with each other and pressing them with a load of 7 MPa (1400 kgf per 2 inch substrate) with a press device (wafer bonder), the silicon dioxide layers are joined together, The laminated support substrate 1 and the GaN substrate 30 were bonded together. The thus obtained laminated laminated substrate 2 was gradually heated from room temperature (25 ° C.) to 300 ° C. in the air over 3 hours, thereby increasing the bonding strength at the bonding interface. Here, in the laminated substrate 2, the thickness of the silicon dioxide layer (first transparent layer 23) disposed between the amorphous silicon layer (photothermal conversion layer 21) of the intermediate layer 20 and the GaN substrate is 230 nm. there were.

3. Next, referring to FIG. 1C, the laminated laminated substrate 2 was heated to 500 ° C. and stress was applied obliquely to the main surface of the substrate. Thermal stress is applied to the surface P having a depth of about 200 nm from the surface of the N atom, which is embrittled by implantation of a large amount of hydrogen ions in the GaN substrate 30 of the laminated substrate 2, and the GaN substrate 30 is laminated on the surface P described above. The GaN layer 30a having a thickness of 200 nm and the remaining GaN substrate 30b joined to the intermediate layer 20 of the support substrate 1 were separated. Thus, the epitaxial growth laminated support substrate 3 in which the GaN layer 30a having a thickness of 200 nm was formed on the intermediate layer 20 of the laminated support substrate 1 was obtained. Here, the remaining GaN substrate 30b separated from the GaN layer 30a can be reused many times after the surface state (flatness, etc.) of the separation surface is adjusted by a technique such as polishing. As a result, the cost per semiconductor device can be finally reduced.

4). Next, referring to FIG. 1D, a GaN layer having a thickness of 2 μm is formed as a transparent semiconductor layer 40 on the GaN layer 30a of the epitaxial growth support substrate 3 by MOCVD. A buffer layer 41, an n-GaN layer 43 having a thickness of 0.5 μm, three pairs of InGaN layers as a light emitting layer 45 having a thickness of 70 nm, a multiple quantum well layer composed of GaN layers, and a p-GaN layer 47 having a thickness of 80 nm. The layers were deposited in this order. In this way, the laminated support substrate 4 for devices was obtained.

  Here, in the epitaxial growth of the transparent semiconductor layer 40 by the MOCVD method described above, the temperature of the epitaxial growth laminated support substrate 3 was about 1000 ° C. The epitaxial growth support substrate 3 includes a silicon dioxide layer (first transparent layer 23 and second transparent layer) as an intermediate layer 20 between the GaN support substrate (Ga-containing transparent support substrate 10) and the GaN layer 30a. A transparent layer 25) and an amorphous silicon layer (photothermal conversion layer 21) were included, and the silicon dioxide layer and the amorphous silicon layer differed in thermal expansion coefficient from the GaN support substrate and the GaN layer 30a. However, the total thickness of the intermediate layer 20 in this embodiment is 300 nm, and the transparent semiconductor layer 40 that has been epitaxially grown is analyzed by X-ray diffraction, and as a result, the lattice constant almost the same as that of the GaN layer 30a is obtained. It can be said that it has quality. If the total thickness of the intermediate layer 20 is 1 μm or less, since the generated stress is small, the quality of the epitaxially grown transparent semiconductor layer 40 is maintained high. Next, after the device laminated support substrate 4 obtained was taken out from the CVD apparatus, it was annealed at 700 ° C. in a nitrogen / oxygen atmosphere having a total pressure of 1 atm and oxygen of 16 vol%.

5. Next, with reference to FIG. 2 (A), two electrodes were formed on the device multilayer support substrate 4 as described below. A p-electrode resist mask (not shown) is formed by photolithography on the p-GaN layer 47 of the transparent semiconductor layer 40 of the laminated support substrate 4 for devices, and a Ni layer having a thickness of 5 nm is formed by vacuum evaporation. After forming an Au layer having a thickness of 11 nm in this order, an unnecessary portion of the electrode material was removed by removing the p-electrode resist mask, whereby a p-electrode 80 was formed.

  Next, a p-electrode protecting resist mask (not shown) is formed on the p-electrode 80 and its peripheral region by photolithography, and the main surface of the transparent semiconductor layer 40 on the p-GaN layer 47 side using chlorine gas. The mesa etching was performed to a depth of 250 nm to remove the p-GaN layer 47, the light emitting layer 45, and the n-GaN layer 43 in a partial region of the main surface, and the GaN buffer layer 41 was exposed. Thereafter, the p-electrode protecting resist mask was removed. On the exposed GaN buffer layer 41, an n-electrode 90 composed of a 20 nm thick Ti layer and a 300 nm thick Au layer was formed by the same method as the formation of the p-electrode. In order to obtain an ohmic junction between the p-electrode and the n-electrode and the semiconductor layer, the obtained substrate was annealed at 500 ° C. in a nitrogen / oxygen atmosphere having a total pressure of 1 atm and oxygen of 0.4 vol%. Thus, a laminated support substrate 4A for devices with two electrodes was obtained. Thereafter, although not shown, a pad electrode layer composed of a 20 nm thick Ti layer and a 300 nm thick Au layer may be formed on each of the p-electrode and the n-electrode by a lift-off method. .

  As described above, high temperature annealing is required to form a semiconductor device. In the laminated support substrate for a device for producing a semiconductor device, if the Ga-containing transparent support substrate 10, the GaN layer 30a, and the transparent semiconductor layer 40 are materials having different chemical species and different thermal expansion coefficients, peeling at the bonding interface, Alternatively, cracks or the like may occur in the GaN layer 30a and the transparent semiconductor layer 40, but the Ga-containing transparent support substrate 10 (GaN support substrate) and the transparent semiconductor layer 40 (GaN buffer layer 41, n-GaN layer 43, 3 pairs) The light emitting layer 45 and the p-GaN layer 47), which are multiple quantum well layers composed of InGaN layers and GaN layers, are made of the same or similar chemical species as the GaN layer 30a, and the thermal expansion coefficients of those substrates and layers Are the same or approximate to each other, so that peeling at the bonding interface, GaN layer 30a, transparent semiconductor layer 40, etc. Such as the rack can be prevented.

  On the other hand, since a GaN substrate is very expensive, in order to lower the unit price of a semiconductor device as a final product, as described below, a laminated support substrate for devices is changed from a GaN support substrate (Ga-containing transparent support substrate 10). ) Must be separated. The separated GaN support substrate (Ga-containing transparent support substrate 10) can be used again as a GaN support substrate by treating the main surface by the method described below. Thus, by repeatedly using one GaN substrate, the unit price of the semiconductor device as the final product can be reduced.

6). Next, referring to FIG. 2B, an adhesive is formed on the formation surface of the p-electrode 80 and the n-electrode 90 of the laminated support substrate 4A for devices with two electrodes. 51 was spin-coated, and a temporary support sapphire plate (temporary support base material 50) was attached using a wafer bonder in an atmosphere heated to 200 ° C. in a vacuum. The adhesive 51 can be softened again by heating to 200 ° C. in consideration of separating the temporary support sapphire plate from the wafer in a later process, for example, Wafer Bond HT-10 manufactured by Brewer Sciences, 10 was chosen.

Next, the laminated support substrate 4A for devices with two electrodes to which the sapphire plate for temporary support (temporary support base material 50) was attached was set in a laser annealing apparatus (not shown). This laser annealing apparatus can generate a green laser pulse having a wavelength of 532 nm using an Nd: YAG laser and a LiB ₃ O ₅ SHG crystal. This laser annealing apparatus is originally an apparatus for rapidly heating amorphous silicon to several hundred to several hundreds of degrees Celsius by absorbing light of the above wavelength into amorphous silicon, and changing it to polysilicon. is there.

  Using the laser annealing apparatus described above, two electrodes are attached under the conditions that the output is 0.2 W, the repetition period is 10 kHz, the pulse width is 10 ns, the spot size on the amorphous silicon layer is 25 nm in diameter, and the scan speed is 100 mm / s. Laser was irradiated from the GaN support substrate (Ga-containing transparent support substrate 10) side of the device multilayer support substrate 4A, and the GaN support substrate of the device multilayer support substrate 4A with a two-electrode diameter of 2 inches was sequentially scanned. The light having a wavelength of 532 nm is emitted from a GaN support substrate (Ga-containing transparent support substrate 10), a silicon dioxide layer (first transparent layer 23 and second transparent layer 25), a GaN layer 30a, a transparent semiconductor layer 40, and an adhesive. 51 and the temporary support sapphire plate (temporary support base material 50) and the like were not absorbed, but were efficiently absorbed only by the amorphous silicon layer (photothermal conversion layer 21). Thereby, the temperature of the amorphous silicon layer (photothermal conversion layer 21) increased rapidly.

As a result, the bonding surface with the intermediate layer 20 in the GaN support substrate (Ga-containing transparent support substrate 10) located at a short distance of the amorphous silicon layer (photothermal conversion layer 21) has a surface temperature exceeding 900 ° C., Pyrolysis into metal Ga and nitrogen (N ₂ ) gas. On the other hand, the thermal decomposition temperature was not reached on the bonding surface of the GaN layer 30a with the intermediate layer 20. This is because silicon dioxide (having a thermal conductivity lower than that of GaN (having a thermal conductivity of about 100 W · m ⁻¹ · K ⁻¹ ) between the GaN layer 30a and the amorphous silicon layer (photothermal conversion layer 21) ( Since a silicon dioxide layer (first transparent layer 23) having a thickness of 230 nm formed with a thermal conductivity of about 10 W · m ⁻¹ · K ⁻¹ ) is interposed, an amorphous silicon layer (photothermal conversion layer 21) It can be considered that the GaN layer 30a did not reach the thermal decomposition temperature because most of the amount of heat generated in the above was diffused to the GaN support substrate (Ga-containing transparent support substrate 10) side. For the same reason, the temperature of the adhesive 51 portion was suppressed to 100 ° C. or less, and the adhesive 51 was not softened or carbonized. Thus, the metal Ga60 could be deposited only on the bonding surface of the GaN support substrate (Ga-containing transparent support substrate 10) with the intermediate layer 20.

  Next, referring to FIG. 2C, the above-mentioned laminated support substrate for devices 4A with two electrodes on which the metal Ga60 is deposited is placed on a hot plate (not shown) at 60 ° C. The GaN support substrate (Ga-containing transparent support substrate 10) was separated from the intermediate layer 20 by sliding (sliding off) the GaN support substrate in a melted state (29.8 ° C.). Thus, a laminated wafer for devices 5A with two electrodes including the transparent semiconductor layer 40, the GaN layer 30a, and the intermediate layer 20 was obtained. Note that the separated GaN support substrate can be reused by subjecting the main surface to a treatment such as polishing and etching.

7). Step of Producing Transparent Semiconductor Layer Laminated Wafer with Two Electrodes Next, referring to FIG. 2D, the metal Ga60 on the intermediate layer 20 of the laminated wafer for devices 5A with two electrodes is washed with hydrochloric acid to obtain an intermediate layer. 20 (a silicon dioxide layer and an amorphous silicon layer partially polysiliconized) was removed by wet etching using a hydrofluoric acid nitric acid mixed solution. Thus, a transparent semiconductor layer laminated wafer 6A with two electrodes including the transparent semiconductor layer 40 and the GaN layer 30a was obtained.

8). Next, referring to FIG. 2E, a transparent semiconductor layer laminated wafer supporting substrate prepared separately on the GaN layer 30a of the transparent semiconductor laminated wafer 6A with two electrodes as described below with reference to FIG. 70 was bonded.

Here, the prepared transparent semiconductor layer laminated wafer support substrate 70 was a sapphire substrate having a thickness of 150 μm. For the bonding, after cleaning the main surface of the GaN layer 30a of the transparent semiconductor layer laminated wafer 6A with two electrodes, it is put into a plasma etching apparatus, and nitrogen plasma (the plasma conditions are RF 100W and N ₂ gas flow rate 50sccm). The main surface was cleaned by exposure to a chamber pressure of 13.3 Pa.). The main surface of the sapphire substrate (transparent semiconductor layer laminated wafer support substrate 70) was also cleaned, and then oxygen plasma (the plasma conditions were RF of 100 W, O ₂ gas flow rate of 50 sccm, and chamber pressure of 6.7 Pa) To clean the main surface. After the two-electrode transparent semiconductor layer laminated wafer 6A and the sapphire substrate (transparent semiconductor layer laminated wafer support substrate 70) were bonded together, they were pressed and bonded by using a wafer bonder in the air with a load of 7 MPa. .

  Next, referring to FIG. 2 (F), the bonded substrate is heated to 200 ° C., which is the softening temperature of the adhesive, with a hot plate, and the sapphire plate for temporary support (temporary support base) is heated from the bonded substrate. The material 50) was slid off and removed. The adhesive remaining on the p-electrode 80 and n-electrode 90 side on the transparent semiconductor layer 40 was removed with a dedicated remover.

  The semiconductor device 7 which is LED (light emitting diode) was obtained by said process. In such semiconductor devices, general elementalization processes (processes such as scribe, break, die bond, and wire bond) can be applied thereafter.

(Example 2)
1. Manufacturing Process Up to Device Multilayer Support Substrate With reference to FIGS. 1A to 1D, a device multilayer support substrate 4 was obtained in the same manner as in Example 1.

2. Next, referring to FIG. 3A, a vacuum deposition method is performed on the entire surface of the transparent semiconductor layer 40 of the device multilayer support substrate 4 on the p-GaN layer 47 with reference to FIG. Thus, a Ni / Au electrode (specifically, an electrode composed of a Ni layer having a thickness of 5 nm and an Au layer having a thickness of 11 nm) was formed as the p-electrode 80. Thus, a laminated support substrate 4B for a device with one electrode was obtained.

3. Next, referring to FIGS. 3B to 3C, an adhesive 51 is applied on the p-electrode 80 of the laminated support substrate for a device 4B with one electrode. After interposing the temporary support base material 50, the GaN support substrate (Ga-containing transparent support substrate 10) was slid off from the device multilayer support substrate 4B in the same manner as in Example 1. Thus, a laminated wafer for devices 5B with one electrode was obtained.

4). Step of Producing Transparent Semiconductor Layer Laminated Wafer with One Electrode Next, referring to FIG. 3D, in the same manner as in Example 1, the metal Ga 60 and the intermediate layer 20 are formed from the laminated wafer for devices 5B with one electrode. Removed. Thus, a transparent semiconductor layer laminated wafer 6B with one electrode was obtained.

5. Next, referring to FIG. 3 (E), the entire surface of the main surface (N atom surface) of the Ga layer 30a of the transparent semiconductor layer laminated wafer 6B with one electrode is formed by vacuum evaporation. A Ti / Al electrode (specifically, an electrode composed of a 20 nm thick Ti layer and a 300 nm thick Au layer) was formed as the electrode 90. Next, on the n-electrode, by a vacuum vapor deposition method, a conductive adhesive layer 95a is composed of a Ti / Al layer (specifically, a Ti layer having a thickness of 20 nm and an Au layer having a thickness of 300 nm). A pad electrode layer was formed.

Next, an n-type conductive Si substrate doped with P (phosphorus), which is a conductive substrate, at a high concentration of 1 × 10 ¹⁹ cm ⁻³ was prepared as the transparent semiconductor layer laminated wafer support substrate 70. On the main surface of this n-type conductive Si substrate, a Ti / Al layer (specifically, a Ti layer having a thickness of 20 nm and an Au layer having a thickness of 300 nm is formed as a conductive adhesive layer 95b by vacuum deposition. Layer electrode) for bonding was formed.

  Next, referring to FIG. 3F, a bonding pad electrode layer (conductive adhesive layer 95a) formed on the transparent semiconductor layer laminated wafer 6B with one electrode, and an n-type conductive Si substrate (transparent The laminated pad electrode layer (conductive adhesive layer 95b) formed on the semiconductor layer laminated wafer supporting substrate 70) is superposed and heated to 400 ° C. while being pressed with a 3 MPa load with a wafer bonder kept in a vacuum state. By joining, it bonded and bonded together.

  Next, after bonding, the back surface of the n-type conductive Si substrate (transparent semiconductor layer laminated wafer support substrate 70) is polished and washed to expose a cleaned surface as an n-pad electrode layer 92 by vacuum deposition. / An Au pad electrode layer (specifically, a pad electrode layer composed of a 20 nm thick Ti layer and a 300 nm thick Au layer) was formed.

  Next, referring to FIG. 3G, the bonded substrate is heated to 200 ° C., which is the softening temperature of the adhesive, with a hot plate, and the sapphire plate for temporary support (temporary support substrate) is heated from the bonded substrate. The material 50) was slid off and removed. The adhesive remaining on the p-electrode 80 side on the transparent semiconductor layer 40 was removed with a dedicated remover.

  Further, in order to make the p-electrode 80, the n-electrode 90, and the n-pad electrode layer 92 ohmic, the above bonded substrate is placed in a nitrogen / oxygen atmosphere with a total pressure of 1 atm and oxygen of 0.4 vol%. Annealed at 500 ° C.

  The semiconductor device 7 which is LED (light emitting diode) was obtained by said process. In such semiconductor devices, general elementalization processes (processes such as scribe, break, die bond, and wire bond) can be applied thereafter.

  In the present embodiment, the conductive substrate which is the transparent semiconductor layer laminated wafer support substrate 70 may be a transparent substrate. In such a case, light is extracted from the support substrate side by using a transparent conductive material such as ITO (indium tin oxide) as the n-electrode, the bonding pad electrode layer, and the n-pad electrode layer. Such mounting (so-called p-down mounting) is also possible.

(Example 3)
1. Manufacturing Process Up to Device Multilayer Support Substrate With reference to FIGS. 1A to 1D, a device multilayer support substrate 4 was obtained in the same manner as in Example 1.

2. Next, referring to FIG. 4A, the transparent semiconductor layer laminated wafer support substrate is bonded to the device laminated support substrate. On the p-GaN layer 47 of the transparent semiconductor layer 40 of the device laminated support substrate 4 A Ni / Au electrode (specifically, an electrode composed of a Ni layer having a thickness of 5 nm and an Au layer having a thickness of 11 nm) is formed on the entire surface by vacuum evaporation, and the bonded substrate is placed in a nitrogen / oxygen atmosphere. The p-electrode 80 was formed by annealing at 500 ° C.

  Next, an Ag layer 83 having a thickness of 50 nm is formed on the p-electrode 80 by a vacuum evaporation method, and an ITO (indium tin oxide) layer 84 having a thickness of 200 nm is formed thereon by a sputtering method. A Ti / Au pad electrode layer for bonding was formed as the conductive adhesive layer 85a by vapor deposition.

On the other hand, a transparent semiconductor layer laminated wafer support substrate 70 in which a bonding Ti / Au pad electrode layer (conductive adhesive layer 85b) was formed on the main surface was prepared. As the transparent semiconductor layer laminated wafer support substrate 70, a p-type conductivity Si substrate doped with B (boron), which is a conductive support substrate, at a high concentration of 1 × 10 ¹⁹ cm ⁻³ was used.

  Next, a bonding Ti / Au pad electrode layer (conductive adhesive layer 85a) formed on the device laminated support substrate 4 and a bonding Ti / Au pad electrode formed on the transparent semiconductor layer laminated wafer support substrate 70 The layers (the conductive adhesive layer 85b) were superposed and bonded together by heating and pressing with a wafer bonder at 350 ° C. under the condition of 4 MPa.

3. Next, referring to FIGS. 4B to 4C, a device laminated support substrate 4 </ b> C to which a transparent semiconductor layer laminated wafer support substrate 70 is bonded is described with reference to FIGS. In the same manner as in Example 1, the Ga-containing transparent support substrate 10 was separated. Thus, a laminated wafer for devices 5C with a supporting substrate was obtained.

4). Step of Producing Transparent Semiconductor Layer Laminated Wafer with Support Substrate Next, referring to FIG. 4D, from the device laminated wafer 5C with a support substrate, in the same manner as in Example 1, the metal Ga 60 and the intermediate layer 20 Separated and removed. Thus, a transparent semiconductor layer laminated wafer 6 with a support substrate was obtained.

5. Next, referring to FIG. 4E, a vacuum deposition method is performed on a p-type conductivity Si substrate (transparent semiconductor layer laminated wafer supporting substrate) of a transparent semiconductor layer laminated wafer 6 with a supporting substrate. Thus, a Ti / Au pad electrode layer (specifically, a pad electrode layer composed of a 20 nm thick Ti layer and a 300 nm thick Au layer) was formed as the p-pad electrode layer 86. Further, a Ti / Au electrode (specifically, a 20 nm-thick Ti layer and a thickness) is formed on the GaN layer 30a of the transparent semiconductor layer laminated wafer 6 with a support substrate by a vacuum deposition method and a lift-off method. An electrode composed of a 300 nm thick Au layer) was formed. In order to obtain an ohmic junction between the p-pad electrode layer 86 and the p-electrode 90 and the semiconductor layer, the transparent semiconductor layer laminated wafer 6 with a supporting substrate on which these electrodes were formed was annealed at 500 ° C. in a nitrogen atmosphere. . Thus, a semiconductor device 7 which is an LED was obtained. Thereafter, a general element forming process (processes such as scribe, break, die bond, wire bond) can be applied.

Example 4
This embodiment is applied when the thermal expansion coefficient of the transparent semiconductor layer laminated wafer supporting substrate is the same as or close to the thermal expansion coefficient of GaN.

1. Manufacturing Process Up to Device Multilayer Support Substrate With reference to FIGS. 1A to 1D, a device multilayer support substrate 4 was obtained in the same manner as in Example 1.

2. Next, referring to FIGS. 5A and 5B, an adhesive 51 is interposed on the p-GaN layer 47 of the intermediate layer 20 of the laminated support substrate 4 for devices. After making the temporary support base material 50, the GaN support substrate (Ga-containing transparent support substrate 10) was slid off from the device multilayer support substrate 4 in the same manner as in Example 1. Thus, the device laminated wafer 5 was obtained.

3. Next, with reference to FIG. 5C, in the same manner as in Example 1, the metal Ga 60 and the intermediate layer 20 were removed from the device laminated wafer 5B with one electrode. Thus, a transparent semiconductor layer laminated wafer 6 was obtained.

4). Next, referring to FIG. 5D, a spinel substrate, which is a transparent support substrate, was bonded to the transparent semiconductor layer stacked wafer 6 as the transparent semiconductor layer stacked wafer support substrate 70.

The above bonding is performed by cleaning the main surface of the GaN layer 30a of the transparent semiconductor layer laminated wafer 6 and then putting it in a plasma etching apparatus to form nitrogen plasma (the plasma conditions are RF of 100 W, N ₂ gas flow rate of 50 sccm, chamber The main surface was cleaned by exposure to a pressure of 13.3 Pa. The main surface of the spinel substrate (transparent semiconductor layer laminated wafer support substrate 70) was also cleaned, and then oxygen plasma (plasma conditions were RF of 100 W, O ₂ gas flow rate of 50 sccm, and chamber pressure of 6.7 Pa). ) To clean the main surface. After the transparent semiconductor layer laminated wafer 6 and the spinel substrate (transparent semiconductor layer laminated wafer support substrate 70) were bonded together, they were pressed and bonded in a pressure of 7 MPa using a wafer bonder in the atmosphere. Thereafter, the bonded substrate was slowly heated up to 200 ° C. with a hot plate to increase the bonding strength.

  At this time, referring to FIG. 5 (E), the bonded substrate is heated to 200 ° C. which is the softening temperature of the adhesive. The material 50) was slid off and removed. The adhesive remaining on the p-electrode 80 side on the transparent semiconductor layer 40 was removed with a dedicated remover.

  Thereafter, a normal electrode forming process, for example, 5. A semiconductor device having a p-electrode 80 and an n-electrode 90 on one side using a p-electrode and an n-electrode formation process as described in the process for producing a laminated support substrate for a device with two electrodes (FIG. 5 (see F1)).

  When a transparent and conductive substrate is used as the transparent semiconductor layer laminated wafer support substrate 70, a semiconductor having a p-electrode 80 on one side and an n-electrode 90 on the other side by a normal electrode forming process. A device (see FIG. 5F2) can also be formed.

(Example 5)
In the formation of the intermediate layer 20, a laminated support substrate was prepared in the same manner as in Example 1 except that the thickness of the silicon dioxide layer as the second transparent layer 25 was 40 nm, and the laminated support substrate was laminated and laminated. Laminated substrate, epitaxial growth support substrate, device support substrate, device support substrate with two electrodes, device wafer with two electrodes, transparent semiconductor layer wafer with two electrodes, and semiconductor device did. Compared with the first embodiment, the epitaxial growth of the transparent semiconductor layer 40 is caused by the high temperature at the interface between the amorphous silicon layer (photothermal conversion layer) having a thickness of 60 nm and the silicon dioxide layer (second transparent layer) having a thickness of 40 nm. The occurrence of peeling due to the difference in thermal expansion coefficient was completely prevented. Separation and removal of the metal Ga60 and the intermediate layer 20 by laser irradiation could be performed without any problem. Thereby, the yield of semiconductor devices was improved.

(Example 6)
In the formation of the intermediate layer 20, a laminated support substrate was prepared in the same manner as in Example 2 except that the thickness of the silicon dioxide layer as the second transparent layer 25 was 40 nm, and the laminated support substrate was laminated and laminated. Laminated substrate, epitaxial growth support substrate, device support substrate with one electrode, device support substrate with one electrode, device wafer with one electrode, transparent semiconductor layer laminate wafer with one electrode, and semiconductor device did. Compared with the second embodiment, the epitaxial growth of the transparent semiconductor layer 40 is caused by the high temperature at the interface between the amorphous silicon layer (photothermal conversion layer) having a thickness of 60 nm and the silicon dioxide layer (second transparent layer) having a thickness of 40 nm. The occurrence of peeling due to the difference in thermal expansion coefficient was completely prevented. Separation and removal of the metal Ga60 and the intermediate layer 20 by laser irradiation could be performed without any problem. Thereby, the yield of semiconductor devices was improved.

(Example 7)
In the formation of the intermediate layer 20, a laminated support substrate was produced in the same manner as in Example 3 except that the thickness of the silicon dioxide layer as the second transparent layer 25 was 40 nm, and the laminated support substrate was laminated and laminated. Laminated substrate, epitaxial growth support substrate, device support substrate, device support substrate with support substrate, device support wafer with support substrate, transparent semiconductor layer support wafer with support substrate, semiconductor device did. Compared to Example 3, the epitaxial growth of the transparent semiconductor layer 40 is caused by a high temperature at the interface between the amorphous silicon layer (photothermal conversion layer) having a thickness of 60 nm and the silicon dioxide layer (second transparent layer) having a thickness of 40 nm. The occurrence of peeling due to the difference in thermal expansion coefficient was completely prevented. Separation and removal of the metal Ga60 and the intermediate layer 20 by laser irradiation could be performed without any problem. Thereby, the yield of semiconductor devices was improved.

(Example 8)
In the formation of the intermediate layer 20, a laminated support substrate was prepared in the same manner as in Example 1 except that the thickness of the silicon dioxide layer as the second transparent layer 25 was 40 nm, and the laminated support substrate was laminated and laminated. A laminated substrate, a laminated support substrate for epi growth, a laminated support substrate for devices, a laminated wafer for devices, a transparent semiconductor layer laminated wafer, and a semiconductor device were sequentially produced. Compared with the first embodiment, the epitaxial growth of the transparent semiconductor layer 40 is caused by the high temperature at the interface between the amorphous silicon layer (photothermal conversion layer) having a thickness of 60 nm and the silicon dioxide layer (second transparent layer) having a thickness of 40 nm. The occurrence of peeling due to the difference in thermal expansion coefficient was completely prevented. Separation and removal of the metal Ga60 and the intermediate layer 20 by laser irradiation could be performed without any problem. Thereby, the yield of semiconductor devices was improved.

Example 9
In this example, a case where an SBD (Schottky barrier diode) is manufactured as an example of a power device using the present technology is illustrated.

1. Manufacturing Process Up to Epi-Growing Multilayer Support Substrate With reference to FIGS. 1A to 1C, an epi-growth multi-layer support substrate 3 was obtained in the same manner as in Example 1.

2. Next, referring to FIG. 6A, a carrier concentration of 1 × as the transparent semiconductor layer 40 is formed on the GaN layer 30a of the epitaxial growth support substrate 3 by MOCVD. An n ⁺ -GaN stop layer 42 having a thickness of 10 ¹⁸ cm ⁻³ and a thickness of 0.5 μm and an n-GaN drift layer 44 having a carrier concentration of 7 × 10 ¹⁵ cm ⁻³ and a thickness of 5 μm were sequentially grown. In this way, the laminated support substrate 4 for devices was obtained.

3. Next, referring to FIG. 6B, photolithography is performed on the n-GaN drift layer 44 of the transparent semiconductor layer 40 in the device multilayer support substrate 4. N-GaN drift by surface treatment with 10% by mass hydrochloric acid aqueous solution, EB deposition of Ni / Au layer (specifically, a layer composed of Ni layer of 50 nm thickness and Au layer of 300 nm thickness), and lift-off A Schottky electrode 81 having a diameter of 200 μm was formed on the layer 44. Thus, a laminated support substrate for a device 4D with one electrode was obtained.

4a. Next, as a first example, referring to FIGS. 6B to 6C, a GaN support substrate (Ga-containing transparent support substrate 10) is laminated on a transparent semiconductor layer in the same manner as in Example 1. An SBD of the type replaced with the wafer support substrate 70 was produced. Specifically, the Schottky electrode 81 side of the laminated support substrate 4D for a device with one electrode is attached to a temporary support base material with an adhesive, and a GaN support substrate (Ga-containing transparent support substrate 10) using a laser annealing apparatus. Laser was irradiated from the side to deposit metal Ga60 only on the bonding surface of the GaN support substrate (Ga-containing transparent support substrate 10) with the intermediate layer 20. The GaN support substrate (Ga-containing transparent support substrate 10) is separated by slide-off, and after removing the intermediate layer 20, the main surface (N atom surface) of the GaN layer 30a of the transparent semiconductor layer laminated wafer 6D with one electrode A Ti / Al electrode (specifically, an electrode composed of a 20 nm-thick Ti layer and a 300 nm-thick Al layer) was formed as an n-electrode 90 on the entire surface by vacuum evaporation. Thereafter, a transparent semiconductor layer laminated wafer supporting substrate 70 prepared by forming ohmic electrodes 93 on both main surfaces of an n-type conductive Si substrate doped with P (phosphorus) at a high concentration of 1 × 10 ¹⁹ cm ⁻³ is prepared. The n-electrode 90 and the metal solder 71 were joined. Thereafter, the temporary support substrate was removed to complete the SBD shown in FIG.

  In parallel with the production of the SBD, in the SBD, instead of the n-type conductive Si substrate (transparent semiconductor layer laminated wafer support substrate 70) having the ohmic electrodes 93 formed on both main surfaces, the n-type conductive An SBD using an ohmic electrode 93 formed on both main surfaces of a conductive Ge substrate (transparent semiconductor layer laminated wafer support substrate 70), an Mo thin film, a W thin film, and a Ta thin film was also manufactured.

As for the characteristics of the five types of SBDs thus obtained, the on-resistance is as low as 1.1 mΩ · cm ² , the forward voltage Vf is as low as 1.3 V at a current density of 500 A / cm ² , and the leakage current density is 1 The reverse withstand voltage at × 10 ⁻³ A / cm ² was as high as 350V.

4b. Next, as a second example, with reference to FIGS. 6B and 6D, the transparent semiconductor layer laminated wafer support substrate 70 is disposed on the transparent semiconductor layer 40 side in the same manner as in Example 3. The type of SBD was made. Specifically, after a SiO ₂ insulating layer 82 is formed around the Schottky electrode 81 of the device laminated support substrate 4D with one electrode, an n-type conductive Si substrate (transparent semiconductor layer laminated wafer support) is formed by the metal solder 71. A substrate 70) having an ohmic electrode 73 formed on both main surfaces was joined. In the same manner as described above, an n-type conductive Ge substrate (transparent semiconductor layer laminated wafer) is used instead of the n-type conductive Si substrate (transparent semiconductor layer laminated wafer support substrate 70) in which ohmic electrodes 73 are formed on both main surfaces. A substrate in which ohmic electrodes 73 are formed on both main surfaces of the support substrate 70), and a Mo thin film, a W thin film, and a Ta thin film are joined. After that, each is irradiated with laser from the GaN support substrate (Ga-containing transparent support substrate 10) side using a bonding laser annealing apparatus, and bonded to the intermediate layer 20 in the GaN support substrate (Ga-containing transparent support substrate 10). Metal Ga60 was deposited only on the surface. The GaN support substrate (Ga-containing transparent support substrate 10) is separated by slide-off, and after the intermediate layer 20 is removed, the main surface (N atom surface) of the Ga layer 30a of the transparent semiconductor layer laminated wafer 6D with one electrode A Ti / Al electrode (specifically, an electrode composed of a 20 nm thick Ti layer and a 300 nm thick Au layer) is formed as an n-electrode 90 by vacuum deposition on the entire surface of FIG. The SBD shown in (C) was completed.

As for the characteristics of the five types of SBDs thus obtained, the on-resistance is as low as 1.1 mΩ · cm ² , the forward voltage Vf is as low as 1.3 V at a current density of 500 A / cm ² , and the leakage current density is 1 The reverse withstand voltage at × 10 ⁻³ A / cm ² was as high as 300V.

(Example 10)
This example illustrates the case where a PND (pn junction diode) is manufactured as an example of a power device using the present technology.

1. Manufacturing Process Up to Epi-Growing Multilayer Support Substrate With reference to FIGS. 1A to 1C, an epi-growth multi-layer support substrate 3 was obtained in the same manner as in Example 1.

2. Next, referring to FIG. 7A, a transparent semiconductor layer 40 having a thickness of 0.5 μm is formed on the GaN layer 30a of the epitaxial growth support substrate 3 by MOCVD. N ⁺ -GaN stop layer 42 (carrier concentration: 1 × 10 ¹⁸ cm ⁻³ ), 7 μm thick n-GaN layer 46 (carrier concentration: 3 × 10 ¹⁶ cm ⁻³ ), 0.5 μm thick p A GaN layer 48 (carrier concentration: 7 × 10 ¹⁷ cm ⁻³ ) and a p ⁺ -GaN contact layer 49 (Mg concentration: 1 × 10 ¹⁹ cm ⁻³ ) having a thickness of 75 nm were sequentially grown. In this way, the laminated support substrate 4 for devices was obtained.

3. Next, referring to FIG. 7B, a photolithographic process is performed on the p ⁺ -GaN contact layer 49 of the transparent semiconductor layer 40 in the device multilayer support substrate 4. Lithography, surface treatment with 10 mass% hydrochloric acid aqueous solution, EB deposition and lift-off of Ni / Au (specifically, a layer composed of a Ni layer having a thickness of 50 nm and an Au layer having a thickness of 300 nm), in a nitrogen gas atmosphere A p-electrode 80 having a diameter of 200 μm was formed on the p ⁺ -GaN contact layer 49 by 700 ° C. alloying heat treatment. Thus, a laminated support substrate for devices 4E with one electrode was obtained.

4a. Next, as a first example, with reference to FIGS. 7B to 7C, a GaN support substrate (Ga-containing transparent support substrate 10) is formed as a transparent semiconductor layer laminated wafer in the same manner as in Example 1. A PND of the type replaced with the support substrate 70 was produced. Specifically, the p-electrode 80 side of the laminated support substrate 4E for a device with one electrode is attached to a temporary support base material with an adhesive, and a GaN support substrate (Ga-containing transparent support substrate 10) using a laser annealing apparatus. Laser was irradiated from the side to deposit metal Ga60 only on the bonding surface of the GaN support substrate (Ga-containing transparent support substrate 10) with the intermediate layer 20. The GaN support substrate (Ga-containing transparent support substrate 10) is separated by slide-off, and after the intermediate layer 20 is removed, the main surface (N atom surface) of the Ga layer 30a of the transparent semiconductor layer laminated wafer 6E with one electrode A Ti / Al electrode (specifically, an electrode composed of a 20 nm-thick Ti layer and a 300 nm-thick Al layer) was formed as an n-electrode 90 on the entire surface by vacuum evaporation. Thereafter, a transparent semiconductor layer laminated wafer supporting substrate 70 prepared by forming ohmic electrodes 93 on both main surfaces of an n-type conductive Si substrate doped with P (phosphorus) at a high concentration of 1 × 10 ¹⁹ cm ⁻³ is prepared. The n-electrode 90 and the metal solder 71 were joined. Thereafter, the temporary support base material was removed to complete the PND shown in FIG.

  In parallel with the production of the PND, the PND is replaced with an n-type conductive Si substrate (transparent semiconductor layer laminated wafer support substrate 70) in which ohmic electrodes 93 are formed on both main surfaces. Devices having ohmic electrodes 93 formed on both main surfaces of a conductive Ge substrate (transparent semiconductor layer laminated wafer support substrate 70), devices using Mo thin film, W thin film, and Ta thin film were also produced.

The characteristics of the five types of PNDs thus obtained are all low on-resistance of 0.60 mΩ · cm ² , the forward voltage Vf at a current density of 500 A / cm ² is as low as 4.1 V, and the leakage current density is 1 The reverse withstand voltage at × 10 ⁻³ A / cm ² was as high as 830V.

4b. Semiconductor Device Manufacturing Process Subsequently, as a second example, the transparent semiconductor layer laminated wafer support substrate 70 is disposed on the transparent semiconductor layer 40 side in the same manner as in Example 3 with reference to FIGS. 7B and 7D. The type of PND was made. Specifically, a SiO ₂ insulating layer 82 is formed around the p-electrode 80 of the laminated support substrate 4E for a device with one electrode, and then a p-type conductive Si substrate (transparent semiconductor layer laminate) is formed by metal solder 71. The wafer support substrate 70) was joined to the one having the ohmic electrode 73 formed on both main surfaces. In the same manner as described above, a p-type conductive Ge substrate (transparent semiconductor layer laminated wafer support) is used instead of the p-type conductive Si substrate (transparent semiconductor layer laminated wafer support substrate 70) in which ohmic electrodes 73 are formed on both main surfaces. A substrate in which ohmic electrodes 73 are formed on both main surfaces of the substrate 70), and a Mo thin film, a W thin film, and a Ta thin film are joined. Thereafter, a laser annealing apparatus is used to irradiate the laser from the GaN support substrate (Ga-containing transparent support substrate 10) side, and the bonding surface of the GaN support substrate (Ga-containing transparent support substrate 10) with the intermediate layer 20 Metal Ga60 was deposited only on the substrate. The GaN support substrate (Ga-containing transparent support substrate 10) is separated by slide-off, and after the intermediate layer 20 is removed, the main surface (N atom surface) of the Ga layer 30a of the transparent semiconductor layer laminated wafer 6E with one electrode A Ti / Al electrode (specifically, an electrode composed of a 20 nm thick Ti layer and a 300 nm thick Au layer) is formed as an n-electrode 90 by vacuum deposition on the entire surface of FIG. The PND shown in (D) was completed.

The characteristics of the five types of PNDs thus obtained are as follows: the on-resistance is as low as 0.60 mΩ · cm ² , the forward voltage Vf at a current density of 500 A / cm ² is as low as 4.1 V, and the leakage current density is 1 × 10 6. The reverse withstand voltage at ⁻³ A / cm ² was as high as 800V.

(Example 11)
In this example, a case where a MIS transistor is manufactured as an example of a power device using the present technology is illustrated.

1. Manufacturing Process Up to Epi-Growing Multilayer Support Substrate With reference to FIGS. 1A to 1C, an epi-growth multi-layer support substrate 3 was obtained in the same manner as in Example 1.

2. Next, referring to FIG. 8A, a transparent semiconductor layer 40 having a thickness of 0.5 μm is formed on the GaN layer 30a of the epitaxial growth support substrate 3 by MOCVD. N ⁺ -GaN layer 142 (carrier concentration: 1 × 10 ¹⁸ cm ⁻³ ), 7 μm thick n-GaN layer 144 (carrier concentration: 3 × 10 ¹⁶ cm ⁻³ ), 0.5 μm thick p− A GaN layer 145 (Mg concentration: 7 × 10 ¹⁷ cm ⁻³ ) and an n ⁺ -GaN layer 146 (carrier concentration: 1 × 10 ¹⁸ cm ⁻³ ) having a thickness of 0.5 μm were sequentially grown. In this way, the laminated support substrate 4 for devices was obtained.

3. Next, with reference to FIG. 8 (B), on the transparent semiconductor layer 40 of the device laminated support substrate 4, photolithography is performed using a 10 mass% hydrochloric acid aqueous solution. Surface treatment, Ti layer / Al layer / Ti layer / Au layer are formed by EB deposition and lift-off at a thickness of 20 nm / 100 nm / 20 nm / 300 nm, respectively, and heat-treated at 600 ° C. in a nitrogen gas atmosphere to form an alloy. ^A source electrode 180 was formed on the ⁺ -GaN layer 146.

Further, a part of the n ⁺ -GaN layer 146, the p-GaN layer 145, and the n-GaN layer 144 was etched into a mesa shape by RIE in a part of the transparent semiconductor layer 40 where the source electrode 180 was not formed. A SiO ₂ insulating layer 182 having a thickness of 100 nm was formed on the etched portion (mesa slope) by p-CVD (plasma chemical vapor deposition). Next, by performing heat treatment at 1000 ° C. for 30 minutes in a nitrogen gas atmosphere, interface defects between the SiO ₂ insulating layer 182 and the GaN layers (n ⁺ -GaN layer 146, p-GaN layer 145 and n-GaN layer 144) are reduced. I let you. Next, a gate electrode 183 is formed on the SiO ₂ insulating layer 182 by resistance heating vapor deposition and lift-off of a Ni / Au layer (a layer composed of a Ni layer having a thickness of 50 nm and an Au layer having a thickness of 100 nm). did. Thus, a laminated support substrate 4F for devices with two electrodes was obtained.

4). Next, referring to FIGS. 8B to 8C, a GaN support substrate (Ga-containing transparent support substrate 10) is replaced with a transparent semiconductor layer laminated wafer support substrate 70 in the same manner as in Example 1. A MIS transistor of the type replaced with is manufactured. Specifically, the source electrode 180 and gate electrode 183 side of the laminated support substrate 4F for a device with two electrodes is attached to a temporary support base material with an adhesive, and a GaN support substrate (Ga-containing transparent support is used using a laser annealing apparatus. Laser was irradiated from the substrate 10) side to deposit the metal Ga60 only on the bonding surface of the GaN support substrate (Ga-containing transparent support substrate 10) with the intermediate layer 20. The GaN support substrate (Ga-containing transparent support substrate 10) is separated by slide-off, and after the intermediate layer 20 is removed, the main surface (N atom surface) of the Ga layer 30a of the transparent semiconductor layer laminated wafer 6F with two electrodes A Ti / Al electrode (specifically, an electrode composed of a 20 nm thick Ti layer and a 300 nm thick Al layer) was formed as a drain electrode 190 on the entire surface by vacuum evaporation. Thereafter, a transparent semiconductor layer laminated wafer supporting substrate 70 prepared by forming ohmic electrodes 93 on both main surfaces of an n-type conductive Si substrate doped with P (phosphorus) at a high concentration of 1 × 10 ¹⁹ cm ⁻³ is prepared. Then, the drain electrode 190 was bonded to the metal solder 71. Thereafter, the temporary support base material was removed to complete the MIS transistor shown in FIG.

  In parallel with the manufacture of the MIS transistor, the MIS transistor is replaced with an n-type conductive Si substrate (transparent semiconductor layer laminated wafer support substrate 70) having ohmic electrodes 93 formed on both main surfaces. A MIS transistor using an ohmic electrode 93 formed on both main surfaces of a type conductive Ge substrate (transparent semiconductor layer laminated wafer support substrate 70), a Mo thin film, a W thin film, and a Ta thin film was also produced.

  It was confirmed that the characteristics of the MIS transistor thus obtained all showed good transistor characteristics.

(Example 12)
This example illustrates the case where a HEMT transistor is manufactured as an example of a power device using the present technology.

1. Manufacturing Process Up to Epi-Growing Multilayer Support Substrate With reference to FIGS. 1A to 1C, an epi-growth multi-layer support substrate 3 was obtained in the same manner as in Example 1.

2. Next, referring to FIG. 9A, a transparent semiconductor layer 40 having a thickness of 1.5 μm is formed on the GaN layer 30a of the epitaxial growth support substrate 3 by MOCVD. The undoped GaN layer 244 and the 30 nm thick undoped AlGaN layer 246 (carrier concentration: 3 × 10 ¹⁶ cm ⁻³ ) were sequentially grown. In this way, the laminated support substrate 4 for devices was obtained.

3. Next, referring to FIG. 9 (B), the surface of the laminated support substrate 4 for devices on the transparent semiconductor layer 40 by photolithography, a 10% by mass hydrochloric acid aqueous solution. The undoped AlGaN layer 246 is prepared by performing EB deposition and lift-off on the Ti layer / Al layer / Ti layer / Au layer at a thickness of 20 nm / 100 nm / 20 nm / 300 nm and heat treatment at 600 ° C. in a nitrogen gas atmosphere, respectively. A source electrode 280 electrode and a drain electrode 290 were formed thereon. Further, in a part of the transparent semiconductor layer 40 in which the source electrode 280 and the drain electrode 290 are not formed, a Ni / Au layer (consisting of a Ni layer having a thickness of 50 nm and an Au layer having a thickness of 300 nm is formed on the undoped AlGaN layer 256. The gate electrode 283 was formed by resistance heating vapor deposition and lift-off. Thus, a laminated support substrate 4G for devices with three electrodes was obtained.

4). Next, referring to FIGS. 9B to 9C, a GaN support substrate (Ga-containing transparent support substrate 10) is replaced with a transparent semiconductor layer laminated wafer support substrate (see FIG. 9B to FIG. 9C). A HEMT transistor of the type replaced with 70) was produced. Specifically, the three-electrode (source electrode 280, gate electrode 283, and drain electrode 290) side of the laminated support substrate for devices 4G with three electrodes is attached to a temporary support base material with an adhesive, and a laser annealing apparatus is used. Laser was irradiated from the GaN support substrate (Ga-containing transparent support substrate 10) side, and metal Ga60 was deposited only on the bonding surface of the GaN support substrate (Ga-containing transparent support substrate 10) with the intermediate layer 20. The GaN support substrate (Ga-containing transparent support substrate 10) was separated by slide-off, and after the intermediate layer 20 was removed, the Ga layer 30a of the transparent semiconductor layer laminated wafer 6G with three electrodes was removed by a dry etching method. . As the transparent semiconductor layer laminated wafer support substrate 70, a polycrystalline AlN (aluminum nitride) support substrate and a SiC (silicon carbide) substrate, which are substrates having good insulation and thermal conductivity, were prepared. Two transparent semiconductor layer laminated wafers 6G to which a Ga layer 30a is formed are prepared, and the above two types of transparent semiconductor layer laminated wafer support substrates 70 are vacuum-bonded onto the undoped GaN layers 244, respectively, and temporary support groups are formed. The material was removed to complete the HEMT transistor shown in FIG. It was confirmed that both of the two types of HEMT transistors obtained in this way showed good transistor characteristics.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Laminated support substrate, 2 Laminated laminated substrate, 3 Laminated support substrate for epi growth, Laminated support substrate for 4,4A, 4B, 4C, 4D, 4E, 4F, 4G device, Laminated for 5,5A, 5B, 5C device Wafer, 6, 6A, 6B, 6C, 6D, 6E, 6F, 6G Transparent semiconductor layer laminated wafer, 7 Semiconductor device, 10 Ga-containing transparent support substrate, 20, 20a Intermediate layer, 21 Photothermal conversion layer, 23, 23a, 23b First transparent layer, 25 Second transparent layer, 30 GaN substrate, 30a GaN layer, 30b Remaining GaN substrate, 40 Transparent semiconductor layer, 41 GaN buffer layer, 42 n ⁺ -GaN stop layer, 43, 46 n-GaN Layer, 44, 144 n-GaN drift layer, 45 light emitting layer, 47, 48, 145 p-GaN layer, 49 p ⁺ -GaN contact layer, 50 temporary support substrate, 51 contact Adhesive, 60 metal Ga, 70 transparent semiconductor layer laminated wafer support substrate, 71 metal solder, 73,93 ohmic electrode, 80 p-electrode, 81 Schottky electrode, 82,182 SiO ₂ insulating layer, 83 Ag layer, 84 ITO Layer, 85, 85a, 85b, 95, 95a, 95b conductive adhesive layer, 86 p-pad electrode layer, 90 n-electrode, 92 n-pad electrode layer, 142, 146 n ⁺ -GaN layer, 180, 280 source Electrode, 183, 283 Gate electrode, 190, 290 Drain electrode, 244 Undoped-GaN layer, 246 Undoped-AlGaN layer.

Claims (38)

Forming an intermediate layer including a photothermal conversion layer on a Ga-containing transparent support substrate to produce a laminated support substrate;
Bonding a GaN substrate to the intermediate layer of the laminated support substrate to produce a laminated laminated substrate;
Epi-growth in which a GaN layer is formed on the intermediate layer of the laminated support substrate by separating the GaN substrate of the laminated laminated substrate at a predetermined depth from the bonding surface with the intermediate layer Producing a laminated support substrate for use,
Producing a laminated support substrate for a device by epitaxially growing at least one transparent semiconductor layer on the GaN layer of the laminated support substrate for epi growth; and
The laminated support substrate for a device has a wavelength longer than the wavelength corresponding to the lowest band gap energy among the band gap energies of the Ga-containing transparent support substrate, the GaN layer, and the transparent semiconductor layer, and the photothermal conversion layer. Irradiating light with a wavelength that can be absorbed, the irradiated light is absorbed by the photothermal conversion layer and converted into heat, and the surface in contact with the intermediate layer of the Ga-containing transparent support substrate is decomposed by the heat, A Ga-containing transparent support substrate and the intermediate layer are separated to produce a laminated wafer for devices including the transparent semiconductor layer, the GaN layer, and the intermediate layer;
And a step of preparing a semiconductor device comprising a transparent semiconductor multilayer wafer comprising said GaN layer and the transparent semiconductor layer and removing the intermediate layer from the laminated wafer for the device,
The intermediate layer that have a melting point above 1200 ° C., a method of manufacturing a semiconductor device including the light-to-heat conversion layer. The Ga-containing transparent support substrate and the transparent semiconductor layer have a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm, and the photothermal conversion layer absorbs light for light having a wavelength of 500 nm or more and less than 600 nm. The method for manufacturing a semiconductor device according to claim 1, wherein the coefficient is 1 × 10 ³ cm ⁻¹ or more.   The method for manufacturing a semiconductor device according to claim 1, wherein the intermediate layer further includes a first transparent layer disposed between the photothermal conversion layer of the intermediate layer and the GaN substrate. 4. The method of manufacturing a semiconductor device according to claim 3, wherein the first transparent layer has a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm.   5. The method of manufacturing a semiconductor device according to claim 3, wherein the intermediate layer further includes a second transparent layer disposed between the photothermal conversion layer of the intermediate layer and the Ga-containing transparent support substrate. . The method for manufacturing a semiconductor device according to claim 5, wherein the second transparent layer has a light absorption coefficient of less than 1 × 10 ³ cm ⁻¹ for light having a wavelength of 500 nm or more and less than 600 nm.   The thickness of the said 2nd transparent layer is 0.3 to 2.5 times the thickness of the said photothermal conversion layer, The manufacturing method of the semiconductor device of Claim 5 or Claim 6.   The method for manufacturing a semiconductor device according to claim 5, wherein a thickness of the first transparent layer is larger than a thickness of the second transparent layer.   9. The method of manufacturing a semiconductor device according to claim 1, wherein the light applied to the device multilayer support substrate is laser light having a wavelength of 500 nm or more and less than 600 nm. The method of manufacturing a semiconductor device according to claim 9, wherein the laser beam is a laser beam based on a second harmonic of an Nd: YAG laser beam or an Nd: YVO ₄ laser beam.   When separating the Ga-containing transparent support substrate and the intermediate layer by irradiating the laminated support substrate for devices with light, an interface between the Ga-containing transparent support substrate and the intermediate layer is formed from the Ga-containing transparent support substrate. The method for manufacturing a semiconductor device according to any one of claims 1 to 10, wherein metal Ga is deposited. The photothermal conversion layer, a method of manufacturing a semiconductor device according to any one of claims 1 to 11 is an amorphous silicon layer. The photothermal conversion layer is a layer containing at least one selected from the group consisting of molybdenum, tungsten, tantalum, titanium, platinum, palladium, carbon, silicides thereof, and nitrides thereof. 12. The method for manufacturing a semiconductor device according to any one of items 11 .   The method for manufacturing a semiconductor device according to claim 3, wherein the first transparent layer is any one of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer.   9. The method of manufacturing a semiconductor device according to claim 5, wherein the second transparent layer is any one of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer. The transparent semiconductor layer, a method of manufacturing a semiconductor device as claimed in any one of claims 15 is a Group III nitride semiconductor layer. The GaN substrate manufacturing method of the semiconductor device according the intermediate layer from the bonding section according ions on the surface of the predetermined depth from the surface is injected 1 with any one of claims 16. The semiconductor device further includes a transparent semiconductor layer laminated wafer support substrate for supporting the transparent semiconductor layer laminated wafer,
A step of bonding the transparent semiconductor layer laminated wafer support substrate to the transparent semiconductor layer side of the device laminated support substrate before a step of producing a device laminated wafer after the step of producing the device laminated support substrate and, wherein in the step of manufacturing a semiconductor device, one of claims 1 to 17, further comprising the step of bonding the transparent semiconductor layer laminated wafer supporting substrate to the transparent semiconductor layer stacked wafers, one of the steps 2. A method for producing a semiconductor device according to item 1. The transparent semiconductor layer includes a light emitting layer that emits light having a peak wavelength of 300 nm or more and 550 nm or less at a wavelength shorter than the light irradiated to the device laminated support substrate, and the transparent semiconductor layer laminated wafer support substrate has a wavelength The method for manufacturing a semiconductor device according to claim 18 , wherein a light absorption coefficient with respect to light of 300 nm or more and 550 nm or less is less than 1 × 10 ⁴ cm ⁻¹ . The method for manufacturing a semiconductor device according to claim 19 , wherein the transparent semiconductor layer laminated wafer support substrate includes at least one selected from the group consisting of sapphire, spinel, quartz, aluminum nitride, diamond, and glass. The method for manufacturing a semiconductor device according to claim 18 , wherein the transparent semiconductor layer laminated wafer support substrate has conductivity having a specific resistance of 10 Ωcm or less. The transparent semiconductor layer laminated wafer support substrate includes at least one selected from the group consisting of silicon, gallium arsenide, indium phosphide, and a first metal,
The method of manufacturing a semiconductor device according to claim 21 , wherein the first metal is at least one of molybdenum, tungsten, copper, aluminum, and an alloy thereof. The transparent semiconductor layer includes a light emitting layer that emits light having a peak wavelength of not less than 300 nm and not more than 550 nm at a wavelength shorter than the light irradiated to the laminated support substrate for devices,
19. The semiconductor according to claim 18 , wherein the transparent semiconductor layer laminated wafer supporting substrate has conductivity with a light absorption coefficient of less than 1 × 10 ⁴ cm ⁻¹ for light having a wavelength of 300 nm or more and 550 nm or less and a specific resistance of 10 Ωcm or less. Device manufacturing method. 24. The method of manufacturing a semiconductor device according to claim 23 , wherein the transparent semiconductor layer laminated wafer support substrate includes at least one selected from the group consisting of gallium oxide, silicon carbide, zinc selenide, aluminum nitride, and diamond. A conductive adhesive layer that is disposed between the transparent semiconductor layer laminated wafer support substrate and the GaN layer or the transparent semiconductor layer and has a specific resistance of 10 Ωcm or less including any of a second metal and a conductive oxide; The manufacturing method of the semiconductor device of any one of Claim 21 to 24 containing. 26. The method of manufacturing a semiconductor device according to claim 25 , wherein the second metal is at least one selected from the group consisting of titanium, gold, silver, nickel, aluminum, zinc, germanium, and alloys thereof. 26. The semiconductor device according to claim 25 , wherein the conductive oxide is at least one selected from the group consisting of zinc oxide, gallium oxide, tin oxide, indium zinc oxide, indium tin oxide, and antimony tin oxide. Production method. A Ga-containing transparent support substrate, an intermediate layer disposed on the Ga-containing transparent support substrate, and a GaN layer disposed on the intermediate layer,
The intermediate layer includes a photothermal conversion layer,
The intermediate layer including the photothermal conversion layer has a melting point of 1200 ° C. or higher,
The wavelength of light that can be absorbed by the photothermal conversion layer is longer than the wavelength corresponding to the lowest band gap energy among the band gap energies of the Ga-containing transparent support substrate and the GaN layer and the transparent semiconductor layer,
The light irradiated by the light irradiation is absorbed by the light-to-heat conversion layer and converted into heat, and the surface in contact with the intermediate layer of the Ga-containing transparent support substrate is decomposed by the heat, and the Ga-containing transparent support substrate A laminated support substrate for epitaxial growth in which the intermediate layer and the intermediate layer are separated. The laminated support substrate for epitaxial growth according to claim 28 , wherein the photothermal conversion layer is an amorphous silicon layer. The photothermal conversion layer, molybdenum, tungsten, tantalum, titanium, platinum, palladium, carbon, and their silicides, and claim 28 is a layer containing at least one selected from the group consisting of nitride Laminated support substrate for epi growth. The epitaxial growth according to any one of claims 28 to 30 , wherein the intermediate layer further includes a first transparent layer disposed between the photothermal conversion layer and the GaN layer of the intermediate layer. Laminated support substrate. 32. The laminated substrate for epitaxial growth according to claim 31 , wherein the first transparent layer is any one of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer. 33. The laminated support for epitaxial growth according to claim 31 or 32 , wherein the intermediate layer further includes a second transparent layer disposed between the photothermal conversion layer of the intermediate layer and the Ga-containing transparent support substrate. substrate. The laminated support substrate for epitaxial growth according to claim 33 , wherein the second transparent layer is any one of a silicon dioxide layer, a silicon nitride layer, and a silicon oxynitride layer. The laminated support substrate for epitaxial growth according to claim 33 or 34 , wherein the thickness of the second transparent layer is 0.3 to 2.5 times the thickness of the photothermal conversion layer. The laminated support substrate for epitaxial growth according to any one of claims 33 to 35 , wherein a thickness of the first transparent layer is larger than a thickness of the second transparent layer. 37. A layered support substrate for epitaxial growth according to any one of claims 28 to 36 , and at least one transparent semiconductor layer epitaxially grown on the GaN layer of the layered support substrate for epitaxial growth. Laminated support substrate for devices. 38. The laminated support substrate for a device according to claim 37 , wherein the transparent semiconductor layer is a group III nitride semiconductor layer.

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