JP5225429B2 - Semiconductor thin film manufacturing method and semiconductor device manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a semiconductor thin film and a method for manufacturing a semiconductor device, and in particular, a method for manufacturing a semiconductor thin film by peeling a semiconductor thin film formed on a substrate from the substrate to obtain a semiconductor thin film, and thus obtained. The present invention relates to a method for manufacturing a semiconductor device including a step of fixing a semiconductor thin film to a second substrate.

  A conventional manufacturing method of this type is disclosed in Non-Patent Document 1 below.

  FIG. 32 shows an outline of the manufacturing method disclosed in Non-Patent Document 1. This method includes a step of peeling a semiconductor thin film formed on a first substrate from the first substrate by a chemical lift-off method.

Specifically, a sacrificial layer (Al _0.7 Ga _0.3 As) 202 is provided on the GaAs substrate 201 as shown in FIG. This substrate (GaAs / Al _0.7 Ga _0.3 As / GaAs substrate) is immersed in hydrofluoric acid (HF) to obtain an upper GaAs thin film (FIG. 32B).

Konagai et al., “High-efficiency GaAs thin-film photovoltaic cells by peel-off technology (JOURNAL of Crystal Growth), 45 (1978), 227, 280

  When peeling a semiconductor thin film having a large area by the above method, a long time is required for peeling the semiconductor thin film because the penetration rate of the chemical solution is slow. In order to keep the peeling time short, for example, it can be considered that the semiconductor thin film formed on the semiconductor substrate is divided into an appropriate size and peeled off. In the case of peeling a plurality of patterned semiconductor thin films, for example, it is conceivable to provide a sheet-like support across the plurality of semiconductor thin films, for example, a support such as an adhesive sheet, and peel the plurality of semiconductor thin films. However, in this case, since the space where the chemical solution permeates between the sheet-like support and the substrate provided with the semiconductor thin film is narrow, the chemical solution is still used when applied to a large-area substrate used in mass production. It is considered that there is an inherent problem of insufficient penetration rate. Another problem is that the etching rate is not constant depending on the position on the substrate.

  Thus, for example, it is conceivable to use a porous material as the support, but it has been unclear what type of porous material can favorably support the semiconductor thin film.

  In the process of peeling a semiconductor thin film having a predetermined pattern shape from a semiconductor substrate by chemical etching, the present invention has a high etchant penetration rate for peeling, improves the uniformity of the etching rate, and is good in a short time. An object is to provide a method capable of obtaining a semiconductor thin film.

A method for producing a semiconductor thin film according to the present invention includes:
A method for producing a semiconductor thin film, wherein a plurality of semiconductor thin films formed on a substrate are separated from the substrate by chemical etching using an etchant to obtain a semiconductor thin film,
Providing a coupling support having a photosensitive sheet-like portion for coupling and supporting the plurality of semiconductor thin films on the semiconductor thin film when the semiconductor thin film is on the substrate;
A step of forming a through-hole in the sheet-like portion after providing the sheet-like portion of the connection support on the semiconductor thin film;
The through hole allows the etchant to pass at least in a direction perpendicular to the surface of the substrate.

  According to the production method of the present invention, the penetration rate of the etching solution for peeling is high, the uniformity of the etching rate is improved, and a good semiconductor thin film can be obtained in a short time.

It is a schematic fragmentary sectional view which shows the state in which the laminated structure of the semiconductor thin film was formed in the manufacturing method of the 1st Embodiment of this invention. It is a schematic fragmentary sectional view which shows the state in which the separate support body was formed in the manufacturing method of the 1st Embodiment of this invention. It is a schematic fragmentary sectional view which shows the state which formed the groove | channel in the manufacturing method of the 1st Embodiment of this invention. In the manufacturing method of the 1st Embodiment of this invention, it is a schematic fragmentary sectional view which shows the state in which the connection support body was formed. In the manufacturing method of the 1st Embodiment of this invention, it is a general | schematic fragmentary sectional view which shows the state which removed the dry film resist under it using the mesh structure of the connection support body as a mask. In the manufacturing method of the 1st Embodiment of this invention, it is a general | schematic fragmentary perspective view which shows the state which formed the connection support body. It is a schematic fragmentary sectional view which shows the state which removed the peeling layer in the manufacturing method of the 1st Embodiment of this invention. It is a schematic fragmentary sectional view which shows the semiconductor thin film isolate | separated from the board | substrate in the manufacturing method of the 1st Embodiment of this invention. It is a schematic fragmentary sectional view which shows the state which bonded the semiconductor thin film isolate | separated from the board | substrate to another board | substrate in the manufacturing method of the 1st Embodiment of this invention. In the manufacturing method of the 1st Embodiment of this invention, after bonding a semiconductor thin film to another board | substrate, it is a schematic fragmentary sectional view which shows the state which removed the connection support body and the individual support body. It is a general | schematic fragmentary perspective view which shows the state in which the connection support body was formed in the manufacturing method of the 2nd Embodiment of this invention. In the manufacturing method of the 2nd Embodiment of this invention, it is a schematic fragmentary sectional view which shows the state in which the connection support body was formed. In the manufacturing method of the 2nd Embodiment of this invention, it is a schematic fragmentary sectional view which shows the state before forming a through-hole in a connection support body. It is a general | schematic fragmentary perspective view which shows the state in which the connection support body was formed in the manufacturing method of the 3rd Embodiment of this invention. It is a general | schematic fragmentary sectional view in the position of CC line of FIG. It is a general | schematic fragmentary sectional view in the position of the DD line | wire of FIG. It is a top view of the connection support body used in the 3rd Embodiment of this invention. It is a top view of the connection support body used in the modification of the 3rd Embodiment of this invention. It is a top view of the connection support body used by the other modification of the 3rd Embodiment of this invention. It is a general | schematic fragmentary perspective view which shows the state in which the connection support body was formed in the manufacturing method of the 4th Embodiment of this invention. It is a general | schematic fragmentary sectional view in the position of the EE line | wire of FIG. It is a general | schematic fragmentary sectional view in the position of the FF line | wire of FIG. It is a general | schematic partial bottom view of the connection support body used in the 4th Embodiment of this invention. In the 4th Embodiment of this invention, it is a schematic fragmentary sectional view which shows the state which affixed the photosensitive polymer sheet 41, its exposure, and image development. In the modification of the 4th Embodiment of this invention, it is a schematic fragmentary sectional view which shows the state in which the contact bonding layer was formed. In the modification of the 4th Embodiment of this invention, it is a general | schematic fragmentary sectional view which shows the state which adhere | attached the connection support body in which the contact bonding layer was formed to the separate support body. It is a general | schematic fragmentary perspective view of the connection support body used in the modification of the 4th Embodiment of this invention. It is a general | schematic partial bottom view of the connection support body of FIG. It is the schematic which shows the peeling process in the 5th Embodiment of this invention. It is the schematic which shows the peeling process in the 5th Embodiment of this invention. It is the schematic which shows the peeling process in the 5th Embodiment of this invention. It is a general | schematic fragmentary sectional view which shows the manufacturing method of the conventional semiconductor device.

  Hereinafter, a semiconductor thin film that is mainly used as an LED array will be described, but the present invention is not limited to such an application.

First Embodiment First, as shown in FIG. 1, on a substrate, for example, an n-type GaAs substrate 11, for example, a GaAs buffer layer 12, for example, an AlAs release layer 13, for example, a p-type GaAs lower contact layer 14, for example, p Type Al _x Ga _1-x As lower cladding layer 15, for example, p-type Al _y Ga _1-y As active layer 16, for example, n-type Al _z Ga _1-z As upper cladding layer 17, for example, n-type GaAs upper contact layer 18 is formed.
These layers are obtained by epitaxial growth in order.
Of these layers, the lower contact layer 14, the lower clad layer 15, the active layer 16, the upper clad layer 17, and the upper contact layer 18 form a semiconductor thin film layer 20 a. The semiconductor thin film layer 20a, the buffer layer 12, and the release layer 13 are collectively referred to as a semiconductor epitaxial layer 25a.

  In the semiconductor thin film layer 20a of the stacked structure shown in FIG. 1, a semiconductor element is formed by performing element isolation (for example, etching away to the active layer other than the light emitting region). As will be described in detail below, the semiconductor thin film layer 20a is divided into a plurality of semiconductor thin film pieces by the formation of the grooves 23, and the semiconductor element is formed in each semiconductor thin film piece formation scheduled region. In this embodiment, it is assumed that each semiconductor thin film constitutes an LED array, and an LED array composed of a plurality of LED elements is formed in each semiconductor thin film piece.

  The buffer layer 12 prepares a surface in a good state when forming a good semiconductor epitaxial layer with few defects, and relaxes the mismatch of the lattice constant between the substrate 11 and the AlGaAs layers (14, 15, 17). This is to alleviate the difference in coefficient of thermal expansion between the substrate 11 and the AlGaAs layers (14, 15, 17).

  The peeling layer 13 is for peeling the semiconductor thin film layer 20a (the semiconductor thin film 20 formed by dividing the semiconductor thin film layer 20 as will be described later) from the substrate 11 by chemical etching. Etching is performed on each layer of the semiconductor thin film layer 20a. It is made of a material that can be etched at a high speed by an etching solution having low properties.

The active layer 16 has a composition of Al _y Ga _1-y As, and when the emission wavelength is 760 nm, y = 0.15, and when the emission wavelength is 740 nm, y = 0.2.
The lower clad layer 15 and the upper clad layer 17 are provided to form a double heterostructure by a potential barrier. For example, in Al _x Ga _1-x As and Al _z Ga _1-z As representing the composition, , X = 0.6 and z = 0.6.
The contact layer 18 is n-type GaAs (5 × 10 ^{17 to} 3 × 10 ¹⁸ cm ⁻³ ), and has a high impurity concentration in order to obtain an n-side ohmic contact.

The active layer may be divided into two upper and lower layers, the lower active layer may be p-type, and the upper active layer may be n-type.
Furthermore, the lower contact layer 15 and the lower cladding layer 16 may be n-type, and the upper cladding layer 18 and the upper contact layer may be p-type. In this case, when the active layer is divided into two upper and lower layers, the lower side is n-type and the upper side is p-type.

  In addition, instead of the heterojunction type LED as described above, a homojunction type LED can also be configured. In this case, after each layer is epitaxially grown, impurity diffusion is performed by the solid phase diffusion method from the surface of the uppermost layer to form a pn junction in the active layer. When impurity diffusion is performed in this way to form a pn junction, this impurity diffusion constitutes an element formation step instead of etching away portions other than the light emitting region as described above. Alternatively, an pn junction may be formed by forming an epitaxial layer of the same semiconductor material and forming a p-type layer and an n-type layer by diffusion or epitaxial growth.

  As described above, after element isolation is performed to form an element, a layer 30a serving as an individual support is formed on the semiconductor epitaxial layer 25a. The layer 25a serving as an individual support is formed of, for example, a photoresist material, and is fixed to the semiconductor epitaxial layer 25a by applying or pasting the entire surface of the semiconductor epitaxial layer 25a.

  Thereafter, the layer 30a is selectively exposed using a photomask (not shown) and developed to be patterned to form the individual support 30 (FIG. 2).

  Next, by etching using the individual support 30 as a mask, the semiconductor thin film layer 20a is divided by the etching grooves 23 and patterned to form a plurality of semiconductor thin films 20 (FIG. 3). FIG. 3 shows only two of the plurality of semiconductor thin films.

  This etching is performed until at least a part of the release layer 13 is exposed, for example, until the release layer 13 is divided by the etching groove. In the example shown in the drawing, the etching groove penetrates not only the peeling layer 13 but also the buffer layer 12 located thereunder and reaches the surface of the substrate 11. As a result, the epitaxial layer 25 a is also divided into a plurality of epitaxial films 25.

For example, for etching the layers 15, 16, and 17 formed of AlGaAs and the layers 14 and 18 formed of GaAs, sulfuric acid / persulfate (mixed solution of sulfuric acid, hydrogen peroxide and water / H ₂ SO) is used as an etchant. ₄ : H ₂ O ₂ : H ₂ O = 16: 1: 1), or phosphoric acid perwater (a mixed solution of phosphoric acid, hydrogen peroxide, and water), or a citric acid-based etchant.

  The size of each semiconductor thin film 20 (sometimes referred to as a “thin film piece” or “chip”) is, for example, 10 μm to 200 μm when an LED array is formed of the semiconductor thin film 20, and may be used for other applications. It is in the range of about 5 mm or less.

  Next, as shown in FIG. 4, for example, a positive dry film resist 41 a is attached to the upper surface of the individual support 30, and then a mesh-like connection support 40 is thermocompression bonded onto the dry film resist 41 a.

The dry film resist 41a is bonded to the lower surface of the mesh-like connection support body 40 and the upper surface of the individual support body 30 by thermocompression bonding, thereby bonding the connection support body 40 to the individual support body 30.
For example, the positive dry film resist 41a can also selectively remove an exposed region by a generally known photolithography process (a process including resist exposure and development).

  The connecting support 40 is formed in a mesh shape so that an etching solution can easily pass when the peeling layer 13 described later is etched, and has an opening 45 between adjacent linear members. The mesh-shaped connecting member is formed, for example, by weaving a group of vertical linear members 43 and a group of horizontal linear members 44. The linear member which comprises a mesh is formed with the metal wire which has acid resistance with respect to the etching liquid used, for example. Alternatively, it is possible to use a core wire which itself does not have acid resistance and is coated with an acid resistant polymer such as polyimide.

  As described above, after obtaining the structure in which the connecting support 40 is provided on the dry film resist 41a, the dry film resist is formed using the linear members 43 and 44 forming the mesh of the connecting support 40 as a photomask. Exposure and development. As a result, the portion of the dry film resist 41a aligned with the mesh linear members 43 and 44 remains and becomes the adhesive layer 41, and the portion not aligned with the mesh linear member, that is, the portion aligned with the mesh opening 45. The resist material 41a is removed (FIGS. 5 and 6).

In FIG. 6, the adhesive layer 41 is omitted, and details of the semiconductor epitaxial layer 25 are omitted.
4 and 5 are schematic partial cross-sectional views taken along the line AA in FIG. FIG. 7, FIG. 8, FIG. 9, and FIG. 10, which will be described later, are also schematic partial sectional views at the same position.

The individual supports 30 are respectively provided corresponding to the semiconductor thin films 20 and support the corresponding semiconductor thin films 20.
The connection support body 40 is common to the plurality of individual support bodies 30 and supports them by connecting them to each other.
As described above, since the semiconductor thin film 20 is formed by etching the semiconductor thin film layer 20a using the individual support 30 as a mask, the semiconductor thin film 20 is formed on the individual support 30 in a self-aligning manner.

Next, as shown in FIG. 7, the semiconductor epitaxial substrate (that is, the combination of the substrate 11 and the plurality of epitaxial films 25) provided with the connection support 40 and the individual support 30 shown in FIGS. The semiconductor thin film 20 is peeled from the substrate 11 (and the buffer layer 12) by immersing in an etching solution for the purpose, dissolving or decomposing the peeling layer 13.
As an etching solution for peeling, the etching rate of the peeling layer 13 is high, and the etching rate of each layer (14, 15, 16, 17, 18) of the semiconductor thin film 20 is low, for example, 10% hydrofluoric acid (HF ) Is used.
At the time of peeling, the etching solution passes through the mesh opening 45 of the connection support 40 and further passes through the etching groove 23 between the epitaxial films 25 to reach the peeling layer 13.

  Since the etching solution can pass through the openings of the mesh-like connection support 40 and a uniform peeling rate can be obtained over the entire surface of the semiconductor wafer, the semiconductor thin film can be peeled uniformly.

  If the mesh size of the mesh-shaped connecting support 40 is too small, the etching solution becomes difficult to pass due to surface tension or the like. For example, the size of the opening 46 is 0.5 mm or larger. It is good to use. The surface is desirably hydrophilized.

On the other hand, the mesh eye needs to be smaller than the dimension of the thin film piece (chip) to be supported in at least one direction. This is because if the mesh eye is larger than the thin film side in any direction, it may not be supported.
In the illustrated example, the mesh opening 45 is substantially square and the semiconductor thin film 20 is rectangular. Therefore, the length of the square side constituting the mesh opening 45 is smaller than the length of the long side of the semiconductor thin film 20. It is.

Next, as shown in FIG. 8, a plurality of semiconductor thin films are transported while holding the connection support 40 (for example, a frame (not shown) provided on the periphery of the connection support 40) while holding it with a jig (not shown). Next, 20 is moved in a lump, and then fixed to a predetermined region on a heterogeneous substrate, for example, a Si substrate 51, as shown in FIG. At this time, for example, the lower contact layer 14 of the semiconductor thin film 20 is bonded to the conductive layer (metal layer) 52 on the Si substrate 51.
In this bonding step, pressurization can be performed with an appropriate pressure in order to obtain a desired bonding strength. Moreover, you may heat suitably.

  Next, the structure including the bonded substrate 51, the semiconductor thin film 20, the support 30, and the support 40 is individually separated from the connection support 40 by a treatment such as immersing in a solvent that decomposes or dissolves the individual support 30. The support 30 is removed, and a combination of the substrate 51 and the semiconductor thin film 20 is obtained (FIG. 10).

Various modifications can be made to the embodiment described above. For example, the conductive layer 52 on the Si substrate 51 may be omitted.
Instead of the Si substrate 51, a substrate made of another material, for example, a glass substrate, a metal substrate, a ceramic substrate, or a substrate coated with an insulating film such as a SiO ₂ film may be used.
The present invention can also be applied to the case where a substrate or a layer of another material is used instead of the GaAs substrate 11 or the AlGaAs layer (15, 16, 17) constituting the semiconductor thin film.

  In the first embodiment of the present invention, the etching solution can pass through the openings (mesh eyes) of the mesh-like connection support 40 in the step of chemically etching the semiconductor thin film and peeling it from the substrate. A uniform peeling rate can be obtained over the entire surface of the semiconductor wafer, and a uniform semiconductor thin film can be peeled off.

Second Embodiment In the first embodiment described above, the mesh-like connection support 40 is used as the connection support, but a connection support 60 as shown in FIGS. 11 and 12 is used instead. It is also good. FIG. 12 is a schematic partial cross-sectional view taken along the line BB in FIG.

  The connection support body 60 shown in FIGS. 11 and 12 is for connecting and supporting a plurality of individual support bodies 30 like the connection support body 40 of the first embodiment. It differs in that it has a through hole 61 and is formed of, for example, a photosensitive polymer sheet.

The photosensitive polymer sheet itself has adhesiveness. As the photosensitive polymer sheet, for example, it is desirable to use a dry film resist.
When the dry film resist is laminated, it is bonded to, for example, the upper surface of the individual support 30 by heating and pressure bonding. Further, it can be selectively removed by exposure and development. Further, after post-baking, the adhesiveness to the individual support 30 is maintained, while the other surface, for example, the upper surface has no adhesiveness.
In the present embodiment, the dry film resist as described above is used as the photosensitive polymer sheet, and is adhered to the individual support 30 with its own adhesiveness. Therefore, the separate adhesive layer 41 used in the first embodiment is not necessary.

The structure provided with the connection support body 60 as described above is obtained as follows.
For example, following FIG. 3, as shown in FIG. 13, a dry film resist 60 a to be the connection support body 60 is pasted (laminated) on the individual support body 30. At this time, for example, the photosensitive polymer can be fixed on the individual support 30 by its own adhesiveness under appropriate pressure and heating.

  Next, a plurality of through holes 61 having a predetermined arrangement are formed in the dry film resist 60a by a photolithography process (exposure, development) to obtain the connection support 60 (FIGS. 12 and 11). In the exposure process, a photomask corresponding to the pattern of the through holes 61 is used.

The through hole 61 desirably has a hole diameter of, for example, 0.5 mm or more in order to improve the passage of the etching solution used for etching the peeling layer 13 in the peeling process. Further, the surface of the connection support 60 is preferably subjected to a hydrophilic treatment.
On the other hand, the diameter of the through hole 61 needs to be smaller than the dimension of the thin film piece (chip) in at least one direction. This is because if the diameter of the through hole is larger than the dimension of the thin film piece in any direction, the connection support 60 may not support the thin film piece.

  After the through hole 61 is formed, post-baking is appropriately performed to improve the chemical resistance of the connection support 60 with respect to the chemical used in the subsequent process.

  Thereafter, the semiconductor thin film is peeled off, bonded to a different substrate, and the support is removed by the same steps as those in FIGS. 7 to 10 described for the first embodiment.

  Since the etching solution passes through the through-hole 61 of the connection support 60 at the time of peeling, a uniform peeling speed can be obtained over the entire surface of the semiconductor wafer, as described in the first embodiment. The semiconductor thin film can be peeled off.

  Further, the size and shape of the through hole 61 can be freely adjusted according to the size of the semiconductor thin film 20 and the characteristics of the etching solution used.

In the example described with reference to FIG. 11 to FIG. 13, the connection support is formed of a photosensitive polymer sheet. However, the photosensitive polyimide formed in advance in a sheet state like a dry film is used. The provided photosensitive polyimide sheet may be used. The photosensitive polyimide sheet can be produced, for example, as follows. First, liquid photosensitive polyimide (exactly photosensitive polyamide) is applied to a desired thickness on a film such as polyethylene terephthalate, the solvent is dried, and a cover film such as polyethylene is provided thereon.
Here, an outline of the photosensitive polyimide will be described below.
Normal polyimide (non-photosensitive polyimide) is prepared by heating the precursor polyamic acid (obtained by reacting aromatic anhydride and diamine) at about 350 ° C. to remove water molecules from the polyamic acid. A ring is formed to form a poimide. In contrast, photosensitive polyimide is a photosensitive polyimide. An aromatic anhydride (eg, hydroxyethyl methacrylate) is reacted with an aromatic anhydride to form a dicarboxylic acid, which is reacted with a diamine to form a polyamide having a double bond in the side chain. This corresponds to a structure in which the carboxyl group of the polyamic acid is replaced with a structure having a polymerizable double bond. A photosensitive polyimide is obtained by dissolving this polymer in a polar solvent such as NMP (n-methylpyrrolidone) together with a photoinitiator, a sensitizer, and an adhesion assistant.
Next, pattern formation using this photosensitive polyimide (negative type) will be described. First, photosensitive polyimide is applied by spin coating to an appropriate thickness (for example, 10 μm), and the solvent is dried. Next, exposure is performed using a predetermined photomask. The radical generated from the photoinitiator by this exposure causes a polymerization reaction between the double bonds of the side chains of the polyamide (starting polymer) to form a crosslinked structure. The starting polymer is dissolved (developed) with an organic solvent and heat-treated at about 350 to 400 ° C., whereby the cross-linked chain portion is detached (thermally decomposed and volatilized), and a polyimide structure is formed in the exposed region.

Third Embodiment In the second embodiment, the coupling support 60 is formed of a photosensitive polymer sheet. Instead, as shown in FIGS. 14, 15, 16, and 17, a polymer is used. A polymer sheet 80 obtained by bonding an adhesive layer 84 to a sheet base 83 can be used as a connection support. 15 is a schematic partial cross-sectional view at the position of line CC in FIG. 14, and FIG. 16 is a schematic partial cross-sectional view at the position of line DD in FIG. FIG. 17 is a plan view of the connection support 80. The illustrated connection support 80 has, for example, a slit-shaped through hole 81.

The structure provided with the support 80 as described above is obtained as follows.
Apart from the construction of the structure shown in FIG. 3, a connection support 80 provided with a through hole 81 is prepared.
And the connection support body 80 which provided the through-hole 81 previously as mentioned above to the structure shown in FIG. 3 is affixed on the individual support body 30 (laminate). At this time, the individual support 30 and the connection support 80 are fixed by the adhesive layer 84 of the connection support 80.

  The through-hole 81 desirably has a width of, for example, 0.5 mm or more in order to improve the passage of the etching solution used for etching the peeling layer 13 in the peeling process. The surface of the connecting support 80 is preferably subjected to a hydrophilic treatment.

  On the other hand, the width of the through hole 81 should be smaller than the size of the thin film piece (chip) (the dimension in the same direction as the width of the through hole 81). This is because if the through hole 81 is larger than the size of the thin film piece in any direction, the thin film piece may not be supported by the connection support 80.

Thereafter, the semiconductor thin film is peeled off, bonded to a different substrate, and the support is removed by the same steps as those in FIGS. 7 to 10 described for the first embodiment.
Since the etching solution passes through the through-hole 81 of the connection support 80 at the time of peeling, a uniform peeling speed can be obtained over the entire surface of the semiconductor wafer, as described in the first embodiment. The semiconductor thin film can be peeled off.

  The size and shape of the through hole can be freely adjusted according to the size of the semiconductor thin film 20 and the characteristics of the etching solution used.

Modified Example of Third Embodiment When the through hole 81 has a slit shape as in the above example, it may be a continuous slit over the entire area of the GaAs substrate (wafer), or may be an intermittent slit ( It may be discontinuous and provided with an appropriate interval between them.
The through hole may have a shape other than the slit shape, for example, a square shape as shown in FIG.

  Moreover, as the connection support body 80, as shown in FIG. 19, you may use the thing provided with the rigid (rigid) flame | frame 85 in the peripheral part, and being fixed by this.

  According to the third embodiment of the present invention, in addition to the effects obtained in the first and second embodiments, the connection support 80 and the individual support 30 are newly bonded. Since there is no need to provide another layer, there is an effect that the process can be omitted.

Fourth Embodiment As a connection support, a connection support 90 shown in FIGS. 20 to 23 can be used instead of the one described in the first to third embodiments. 20 is a schematic partial perspective view of the connection support 90 fixed on the thin film, FIG. 21 is a schematic partial cross-sectional view taken along line EE in FIG. 20, and FIG. 22 is a line FF in FIG. FIG. 23 is a schematic partial sectional view of the connection support.

The connection support body shown in FIGS. 20 to 23 is for connecting and supporting a plurality of individual support bodies 30 in the same manner as the connection support body 40 described in the first embodiment.
The connection support 90 includes a sheet-like portion 91 and a bridge-girder-shaped spacer portion 92 in order to provide a space between the sheet-like portion 91 and the individual support 30 and to allow more etching solution to pass therethrough.
Such a connecting support 90 is formed in advance by precision machining (before being placed on the thin film).

  A tacky material, that is, a material having tackiness or adhesiveness, for example, a photosensitive polymer material is provided in an adhesion region between the connection support 90 and the individual support 30. Here, as the photosensitive polymer material, for example, a liquid resist or a dry film resist is provided as the adhesive layer 41.

  The connection support 90 of the present embodiment includes, for example, a transparent material such as quartz, sapphire, and acrylic, a metal material coated with polyimide, a ceramic material, a polytetrafluoroethylene (Teflon (registered trademark) material, and a polyethylene material. It is desirable to form with a semiconductor material such as Si.

  Hereinafter, the example of the manufacturing method of a semiconductor thin film is demonstrated about the case where the connection support body 90 is formed with a transparent material.

First, a structure including the connection support 90 as described above is obtained as follows.
In the creation of the structure shown in FIG. 3, the connection support 90 is separately created by precision machining.

  Then, after the structure shown in FIG. 3 is created, the dry film resist 41a is pasted (laminated) on the surface of the individual support 30, and the connection support 90 is further spaced by the spacer 92 on the individual support 30. It is placed so as to be in contact with the photosensitive polymer sheet 41a, attached, heated, and pressed, and fixed to the individual support 30 (FIG. 24A).

Next, the dry film resist 41a other than the spacer portion 92 of the connection support 90 is removed to form the adhesive layer 41 (FIG. 22).
For example, the dry film resist 41a other than the spacer portion 92 can be removed by performing generally known exposure and development on the dry film resist 41a. In this exposure and development process, a photomask can be positioned on the connection support 90 and exposed. FIG. 24B shows a schematic example of this process. Here, the structure when a negative type dry film (41a) is assumed is shown. As shown in FIG. 24B, a photomask 95 having an opening 96 is placed on the connection support 90 in accordance with the position of the spacer 92. Next, the resist 41a is exposed through this photomask. The resist is polymerized in the region 41e where the light hits to form a crosslinked structure. By removing the unexposed area with the developer, the exposed area (resist under the spacer area) 41e remains. Since the resist 41a is already bonded to the spacers of the individual support and the connection support before development, the connection support is fixed to the individual support. Here, the photomask surface and the resist surface are separated from each other, and light spreads wider than the width of the opening portion 96 of the photomask. Here, the main purpose is adhesion between the spacer and the individual support, and the width of the exposure region 41e. The spread of the resist, and hence the spread of the remaining resist width (pattern formation accuracy) is not a problem here.

  As described above, instead of forming the adhesive layer 41 with a photosensitive polymer such as a dry film / resist, the adhesive layer 41b can be formed with an adhesive. The steps in this case are as follows.

A liquid pressure-sensitive adhesive or adhesive is applied to the lower surface of the spacer portion 92 of the connection support 90, and then the solvent component is volatilized to form an adhesive layer 41b having an appropriate hardness and adhesive (FIG. 25). ).
After that, the spacer 90 is aligned with the pattern of the individual support 30 of the structure shown in FIG. 3 and the bonding layer 41b is pressed against the surface of the individual support 30 to adhere the connection support 90 (see FIG. 3). FIG. 26).

The adhesive (41b) applied to the lower surface of the spacer portion 92 may be photocurable or thermosetting, or may be a material that does not have these properties.
Further, the adhesive (41b) applied to the lower surface of the spacer portion 92 needs not to be dissolved or decomposed by the etching solution when the semiconductor thin film 20 is immersed in the etching solution for peeling the semiconductor thin film 20 from the substrate 11.

  The connection support 90 is formed as described above, and after obtaining the structure shown in FIG. 20 to FIG. 22 or the structure shown in FIG. 25, the first embodiment has been described. The semiconductor thin film is peeled off, bonded to a different substrate, and the support is removed by the same process as 10.

  At the time of peeling, the etching solution passes through the space 93 (FIG. 20) formed between the sheet-like portion 91 and the upper surface of the individual support 30 by the spacer portion 92 of the connection support 90 (the arrow in FIG. 20). 94), a uniform peeling rate can be obtained over the entire surface of the semiconductor wafer, and a uniform semiconductor thin film can be peeled off, as described in the first embodiment.

Modification of Fourth Embodiment Instead of the connection support 90 shown in FIGS. 20 to 22, the connection support 100 shown in FIGS. 27 and 28 can be used. FIG. 27 is a schematic partial perspective view of the connection support 100 fixed on the thin film, and FIG. 28 is a schematic partial bottom view of the connection support 100. This connection support body 100 has a sheet-like portion 101 and a spacer portion 102 similarly to those shown in FIGS. 20 to 22, but is further different in that a through-hole 103 is provided in the sheet-like portion 101.

  Providing the through hole 103 in this way increases the inflow path of the etching solution, further increases the etching rate, and further improves the uniformity of the etching rate.

  The method of fixing the connection support 100 shown in FIGS. 27 and 28 to the thin film is the same as that described in the examples of FIGS.

Fifth Embodiment The peeling process of the first to fourth embodiments can be performed as shown in FIGS. The peeling process shown in FIGS. 29 to 31 is characterized by a method of introducing an etching solution for peeling into the space between the support and the semiconductor thin film. In FIG. 29 thru | or FIG. 31, it has illustrated as a thing using the connection support body 90 demonstrated in 4th Embodiment.

As described with reference to FIG. 20, the structure (substrate before thin film peeling) 110 to which the connection support 90 is fixed and the etching solution tank 111 are installed in the vacuum layer 112.
Next, the inside of the vacuum chamber 112 is depressurized. Here, a low degree of vacuum is sufficient, for example, about 0.1 Torr.

  Next, as shown in FIG. 30, a reduced pressure state is maintained, and the substrate 110 before thin film peeling is immersed in the etching solution tank 111, for example, maintained for about 1 minute to 1 hour. Here, since all the voids in the substrate 110 before thin film peeling are reduced in pressure, the immersion of the etching solution into the voids in the substrate 110 before peeling the semiconductor thin film by immersing in the etching solution tank 111 causes the semiconductor to The voids in the substrate 110 before thin film peeling are filled with the etching solution.

  Next, as shown in FIG. 31, the vacuum chamber 112 is opened to atmospheric pressure and left in a state of being immersed in an etching solution for about 1 hour to 100 hours, for example.

  When peeling is completed in this manner, bonding to the different substrate 51 and removal of the support are performed by the same steps as in FIGS.

  According to the fifth embodiment, since the immersion in the etching solution is performed in the vacuum chamber, the etching solution quickly penetrates into the gap, and uniform etching can be performed. If the vacuum chamber is used as in the fifth embodiment, for example, the size of the mesh opening of the mesh connection support body 40 of the first embodiment or the connection support body 60 described in the second embodiment. The diameter of the hole to be formed may be 0.5 mm or less, for example, 50 μm to 500 μm.

In each of the above embodiments, the individual support 30 can be omitted.
For example, in the example of FIG. 20, the individual support 30 is omitted, and the connection support 90 is bonded directly on the upper contact layer 18.
This adhesion is performed after peeling of the semiconductor thin film 20 and bonding to another substrate (51), followed by heating, light irradiation, immersion in a stripping solution, immersion in an organic solvent, vacuum (keep in a vacuum), magnetic It is desirable that the adhesion between the connection support 90 and the semiconductor thin film surface be promptly released by an appropriate means such as an action.

  Further, the material of the semiconductor thin film 20 and the like need not be limited to the exemplified materials. For example, other compound semiconductor materials such as AlGaInP, InGaAsP, GaN, AlGaN, and InAlGaN may be used. However, it may be Si-based.

  Various modifications can be made to the material of the support, and the modes described in the present invention can be combined as appropriate.

Furthermore, in the present invention, an example in which all the semiconductor thin films 20 on the substrate 11 are peeled off at once and bonded together is described. For example, a group of a plurality of semiconductor thin films 20 on the semiconductor substrate 11 is divided into a plurality of groups. It is possible to deform such as dividing, peeling for each group, and bonding.
In addition, various peeling processes can be performed using the form of supporting the semiconductor thin film 20 described in the present embodiment.

  If the mesh size or the size of the through hole (the diameter of the circular through hole or the width of the rectangular through hole) is small, the passage of the chemical solution is hindered by the surface tension. It is necessary to have. For example, it should be 0.5 mm or more. On the other hand, the mesh size and the size of the through-hole (the diameter of the circular through-hole and the width of the slit-shaped through-hole) are smaller than the size of the thin film piece (chip) (the size in the same direction) in any direction. If it is too large, the thin film pieces may not be supported by the connecting support, so the mesh size and the through hole width should be smaller than the corresponding dimensions of the thin film pieces in at least one direction. The gap between the support and the semiconductor thin film is evacuated and then immersed in a chemical solution, so that the size of the mesh or the through hole can be made small, for example, 50 μm to 500 μm.

Moreover, it is desirable to use the surface of the mesh or sheet used as the connection support so as to make the etching solution easy to enter.
Further, the individual support may be similarly subjected to a hydrophilic treatment. Moreover, you may mix | blend the surfactant which reduces surface tension in etching liquid.

  11 Substrate, 12 Buffer layer, 13 Release layer, 14 Lower contact layer, 15 Lower cladding layer, 16 Active layer, 17 Upper cladding layer, 18 Upper contact layer, 20 Semiconductor thin film, 23 Groove, 25 Epitaxial film, 30 Individual Support, 40 Linked support, 41 Adhesive layer, 41a Dry film resist, 41b Adhesive layer, 43 Vertical linear member, 44 Horizontal linear member, 45 Opening, 51 Substrate, 52 Conductive layer, 60 Connected Support, 61 through-hole, 80 connection support, 81 through-hole, 90 connection support, 91 sheet-like part, 92 spacer part, 93 space, 100 connection support, 101 sheet-like part, 102 spacer part, 103 through-hole 111 etchant tank, 112 vacuum tank.

Claims (9)

A method for producing a semiconductor thin film, wherein a plurality of semiconductor thin films formed on a substrate are separated from the substrate by chemical etching using an etchant to obtain a semiconductor thin film,
Providing a coupling support having a photosensitive sheet-like portion for coupling and supporting the plurality of semiconductor thin films on the semiconductor thin film when the semiconductor thin film is on the substrate;
A step of forming a through-hole in the sheet-like portion after providing the sheet-like portion of the connection support on the semiconductor thin film;
The method for producing a semiconductor thin film, wherein the through hole allows the etching solution to pass in a direction perpendicular to at least the surface of the substrate.   2. The method for producing a semiconductor thin film according to claim 1, wherein the photosensitive sheet-like portion is formed of a photosensitive etching resist material.   The method for producing a semiconductor thin film according to claim 1, wherein the photosensitive sheet-like portion is formed of photosensitive polyimide.   2. The method for producing a semiconductor thin film according to claim 1, wherein the photosensitive sheet-like portion is formed of a photosensitive polymer material.   The method for producing a semiconductor thin film according to claim 1, wherein the size of the through hole is 0.5 mm or more. Further comprising providing a corresponding individual support on each of the plurality of semiconductor thin films,
The method of manufacturing a semiconductor thin film according to claim 1, wherein the step of providing the connection support includes providing the connection support so as to connect the plurality of individual supports.   The method for producing a semiconductor thin film according to claim 1, further comprising a step of hydrophilizing the connection support.   The method for producing a semiconductor thin film according to claim 6, further comprising a step of hydrophilizing the individual support.   A method for manufacturing a semiconductor device, comprising: fixing a semiconductor thin film manufactured by the method according to claim 1 to a second substrate.

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