Semiconductor device transfer method and semiconductor device transfer apparatus

Abstract

The present invention provides a semiconductor element transfer method and a semiconductor element transfer apparatus that enable the irradiation of a laser beam onto the support substrate from the opposite side of the surface supporting the semiconductor component, so as to achieve an appropriate energy density on the surface supporting the semiconductor element, even when the material or thickness of the support substrate is changed. [Solution] The control unit 2 of the semiconductor element transfer apparatus 100 is configured to perform the step of adjusting the distance between the laser light irradiation unit 1 that irradiates the support substrate Su with laser light L1 and the support substrate Su, based on the refractive index n1 of the support substrate Su with respect to the wavelength of laser light L1 irradiated onto the support substrate Su from the side opposite to the surface supporting the semiconductor element El, and the thickness t of the support substrate Su.

Description

Technical Field

[0001] The present invention relates to a semiconductor element transfer method and a semiconductor element transfer apparatus, and particularly to a semiconductor element transfer method and a semiconductor element transfer apparatus for transferring a semiconductor element by irradiating a laser beam from the side opposite to the surface supporting the semiconductor element of a support substrate supporting the semiconductor element.

Background Art

[0002] Conventionally, a semiconductor element transfer method and a semiconductor element transfer apparatus for transferring a semiconductor element by irradiating a laser beam from the side opposite to the surface supporting the semiconductor element of a support substrate supporting the semiconductor element are known (see, for example, Patent Document 1).

[0003] In Patent Document 1, a laser beam is irradiated to a dynamic release layer from the side opposite to the surface to which an individual component (semiconductor element) is attached of a first substrate (support substrate) that supports the individual component by attaching the individual component via the dynamic release layer. As a result, blisters in which the dynamic release layer is plastically deformed are formed in the dynamic release layer. Further, since the contact area between the dynamic release layer and the individual component decreases due to the formation of blisters in the dynamic release layer between the first substrate and the individual component, the individual component is peeled off from the dynamic release layer. As a result, the individual component is transferred to a second substrate arranged to face the individual component.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above-mentioned Patent Document 1, laser light is irradiated from the side of the first substrate supporting the individual components that is opposite to the surface supporting the individual components. Here, although not explicitly stated in Patent Document 1, if the energy density of the laser light irradiated to the surface of the first substrate supporting the individual components (dynamic delamination layer) is high, the dynamic delamination layer will break and blister formation will not occur. Also, if the energy density of the laser light irradiated to the surface of the first substrate supporting the individual components (dynamic delamination layer) is low, blisters of sufficient size to detach the individual components will not be formed. Therefore, in order to properly form blisters on the surface of the first substrate supporting the individual components (dynamic delamination layer) by irradiating with laser light and to detach the individual components from the dynamic delamination layer, it is necessary to irradiate the surface of the first substrate supporting the individual components with laser light of an appropriate energy density. However, since the laser light irradiated onto the first substrate refracts upon passing through the first substrate, when multiple types of substrates with different thicknesses and materials are used as the first substrate, the material and thickness of the first substrate are changed, which causes a shift in the energy density of the laser light on the surface of the first substrate supporting the individual components. Therefore, even when the material or thickness of the first substrate is changed, there is a need for a semiconductor element transfer method and apparatus that can irradiate the first substrate with laser light from the opposite side of the surface supporting the individual components of the first substrate so that the energy density on the surface supporting the individual components (semiconductor elements) of the first substrate (support substrate) is appropriate.

[0006] This invention was made to solve the above-mentioned problems, and one object of this invention is to provide a semiconductor element transfer method and a semiconductor element transfer apparatus that can irradiate the support substrate with laser light from the side opposite to the surface supporting the semiconductor component of the support substrate so that the energy density on the surface supporting the semiconductor element of the support substrate is appropriate, even when the material or thickness of the support substrate is changed. [Means for solving the problem]

[0007] To achieve the above objective, a semiconductor element transfer method according to the first aspect of this invention comprises the steps of: adjusting the distance between a laser beam irradiation unit and a support substrate based on the refractive index of the support substrate with respect to the wavelength of laser light irradiated onto the support substrate from the side opposite to the surface supporting the semiconductor element, and the thickness of the support substrate; and transferring a semiconductor element by irradiating the support substrate with laser light after the step of adjusting the distance between the laser beam irradiation unit and the support substrate.

[0008] As described above, the semiconductor element transfer method according to this first phase includes a step of adjusting the distance between the laser beam irradiation unit and the support substrate based on the refractive index of the support substrate with respect to the wavelength of laser light irradiated onto the support substrate from the opposite side of the support surface of the support substrate that supports the semiconductor element, and the thickness of the support substrate. Here, in the direction of laser beam irradiation, the position where the laser light is focused after passing through the support substrate is determined by the refractive index of the support substrate with respect to the wavelength of the laser light and the thickness of the support substrate. Therefore, by adjusting the distance between the laser beam irradiation unit and the support substrate based on the refractive index of the support substrate with respect to the wavelength of laser light irradiated onto the support substrate from the opposite side of the support surface of the support substrate that supports the semiconductor element, it is possible to suppress the occurrence of a shift in the energy density of the laser light on the surface of the support substrate that supports the semiconductor element due to a change in the material or thickness of the support substrate. As a result, even when the material or thickness of the support substrate is changed, the laser light irradiated onto the support substrate from the opposite side of the support substrate that supports the semiconductor component can be irradiated to have an appropriate energy density on the surface of the support substrate that supports the semiconductor element.

[0009] In the semiconductor element transfer method according to the first aspect described above, preferably, the step of adjusting the distance between the laser light irradiation unit and the support substrate includes the step of adjusting the size of the laser spot of the laser light on the surface supporting the semiconductor element by adjusting the distance between the laser light irradiation unit and the support substrate. Here, the size of the laser spot of the focused laser light gradually decreases up to the position where the laser light is focused, and gradually increases beyond the position where the laser light is focused, so the size of the laser spot of the laser light changes according to the distance from the laser light irradiation unit. Also, if the intensity of the irradiated laser light is not changed, the total energy of the laser light irradiated to each laser spot of different sizes is equal regardless of the size of the laser spot. For this reason, the energy density of the laser light at the laser spot increases as the size of the laser spot decreases. Therefore, the energy density of the laser light on the surface of the support substrate that supports the semiconductor element depends on the size of the laser spot on the surface of the support substrate that supports the semiconductor element. Therefore, by configuring the system to adjust the size of the laser spot of the laser light on the surface of the support substrate that supports the semiconductor element, it is possible to irradiate the surface of the support substrate that supports the semiconductor element with laser light at an appropriate energy density.

[0010] In the semiconductor element transfer method according to the first aspect described above, preferably, the support substrate is provided with an adhesive layer for adhesively supporting the semiconductor element, and the step of adjusting the distance between the laser light irradiation unit and the support substrate is a step of adjusting the distance between the laser light irradiation unit and the adhesive layer based on the refractive index of the support substrate with respect to the wavelength of the laser light and the thickness of the support substrate, and the step of adjusting the distance between the laser light irradiation unit and the support substrate includes a step of calculating the range of the laser focus distance, which is the distance between the lens that focuses the laser light contained in the laser light irradiation unit and the adhesive layer, based on the refractive index of the support substrate with respect to the wavelength of the laser light and the thickness of the support substrate, and a step of adjusting the distance between the lens and the adhesive layer so that the distance between the lens and the adhesive layer falls within the calculated range of the laser focus distance. With this configuration, the distance at which laser light of an appropriate energy density can be irradiated onto the adhesive layer can be calculated as the laser focus distance based on the refractive index of the support substrate with respect to the wavelength of the laser light and the thickness of the support substrate. Furthermore, since the distance between the laser light irradiation unit and the adhesive layer is adjusted so that the adhesive layer falls within the calculated range of the laser focus distance, the adhesive layer can be positioned at a distance at which laser light of an appropriate energy density is irradiated. As a result, even if the material or thickness of the support substrate of the holding substrate is changed, it is possible to irradiate the adhesive layer of the support substrate with laser light of an appropriate energy density in order to properly form a blister, which is a bulge in the adhesive layer used to detach the semiconductor element.

[0011] In the semiconductor element transfer method according to the first aspect described above, preferably, a wavelength different from the wavelength of the laser light and such that the semiconductor element does not peel off from the support substrate is used as the illumination wavelength, and the method further includes a step of adjusting the focus position of an alignment camera that images alignment marks provided on the support substrate, and the step of adjusting the distance between the laser light irradiation unit and the support substrate includes adjusting the distance between the laser light irradiation unit and the support substrate based on the focus position, the refractive index of the support substrate with respect to the illumination wavelength, and the thickness of the support substrate. With this configuration, by using a wavelength such that the semiconductor element does not peel off from the support substrate as the illumination wavelength, it is possible to obtain information for adjusting the distance between the laser light irradiation unit and the support substrate while suppressing the peeling of the semiconductor element. Therefore, the distance between the laser light irradiation unit and the support substrate can be adjusted without affecting the semiconductor element supported on the support substrate.

[0012] A semiconductor element transfer apparatus according to a second aspect of this invention comprises a support substrate on which a semiconductor element is supported, positioned on the opposite side of the surface supporting the semiconductor element, a laser beam irradiation unit that irradiates focused laser light toward the support substrate, and a control unit that controls the distance between the laser beam irradiation unit and the support substrate, wherein the control unit is configured to adjust the distance between the laser beam irradiation unit and the support substrate based on the refractive index of the support substrate with respect to the wavelength of the laser light and the thickness of the support substrate.

[0013] As described above, in the semiconductor element transfer apparatus according to the second aspect of this invention, the control unit is configured to control the distance between the laser beam irradiation unit and the support substrate based on the refractive index of the support substrate with respect to the wavelength of the laser beam and the thickness of the support substrate. Furthermore, in the direction of laser beam irradiation, the position where the laser beam is focused after passing through the support substrate is determined by the refractive index of the support substrate with respect to the wavelength of the laser beam and the thickness of the support substrate. Therefore, by configuring the control unit to control the distance between the laser beam irradiation unit and the support substrate based on the refractive index of the support substrate with respect to the wavelength of the laser beam and the thickness of the support substrate, it is possible to suppress the occurrence of a shift in the energy density of the laser beam on the surface of the support substrate that supports the semiconductor element due to a change in the material or thickness of the support substrate. As a result, even when the material or thickness of the support substrate is changed, it is possible to provide a semiconductor element transfer apparatus that can irradiate the surface of the support substrate that supports the semiconductor element with laser beam of an appropriate energy density. [Effects of the Invention]

[0014] According to the present invention, even when the material or thickness of the support substrate is changed, as described above, it is possible to provide a semiconductor element transfer method and a semiconductor element transfer apparatus that can irradiate the support substrate with laser light from the side opposite to the surface supporting the semiconductor component of the support substrate so that the energy density on the surface supporting the semiconductor element of the support substrate is appropriate. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram of a semiconductor device transfer apparatus according to one embodiment. [Figure 2] This is a flowchart of a method for adjusting the focus position of a laser beam according to one embodiment. [Figure 3] This is a schematic diagram illustrating the focus position of an alignment camera according to one embodiment. [Figure 4] This is a schematic diagram illustrating the focus position of a laser beam according to one embodiment. [Figure 5]This is a schematic diagram illustrating the adjustment of the laser beam focus position according to one embodiment. (a) This diagram shows the laser beam focus position relative to the support substrate for substrate data D1. (b) This diagram shows the laser beam focus position relative to the support substrate for substrate data D2. [Modes for carrying out the invention]

[0016] Hereinafter, an embodiment of the present invention will be described based on the drawings.

[0017] (Configuration of semiconductor device transfer apparatus) Referring to Figures 1 to 5, the configuration of a semiconductor element transfer apparatus 100 according to one embodiment of the present invention will be described. As shown in Figure 1, the semiconductor element transfer apparatus 100 comprises a laser light irradiation unit 1, a control unit 2, a support substrate holding unit 3, an alignment camera 4, and a laser displacement meter 5. In the drawings, the left-right direction (one direction in the horizontal plane) of the semiconductor element transfer apparatus 100 is defined as the X direction. The up-down direction (vertical direction) of the semiconductor element transfer apparatus 100 is defined as the Z direction. The upward direction is defined as the Z1 direction, and the downward direction is defined as the Z2 direction. The direction perpendicular to the X and Z directions (the other direction in the horizontal plane) of the semiconductor element transfer apparatus 100 is defined as the Y direction.

[0018] The laser beam irradiation unit 1 is positioned on the opposite side of the support substrate Su on which the semiconductor element El is supported, and is configured to irradiate focused laser light L1 toward the support substrate Su. Furthermore, an adhesive layer Ad is provided on the surface of the support substrate Su that supports the semiconductor element El, thereby providing adhesive support for the semiconductor element El. That is, the laser beam irradiation unit 1 is positioned on the opposite side of the adhesive layer Ad from the support substrate Su, and is configured to irradiate laser light L1 toward the adhesive layer Ad from the opposite side of the adhesive layer Ad through the support substrate Su. The support substrate Su also has alignment marks M on its surface facing the adhesive layer Ad. For example, the support substrate Su may be made of synthetic quartz or BK7 (borosilicate crown glass) that transmits laser light L1. For example, silicon may be used for the adhesive layer Ad.

[0019] The laser light irradiation unit 1 also includes a laser light source 11, a beam shaper 12, a galvanometer mirror 13, and an fθ lens 14. The laser light source 11 is a light source that emits laser light L1. The wavelength of the laser light L1 is such that it decomposes the adhesive layer Ad and generates gas components. Specifically, the laser light L1 is a pulsed laser with a wavelength of 355 nm. The beam shaper 12 converts the beam profile (spatial intensity distribution of the laser light L1) of the laser light L1 into a predetermined beam profile. Specifically, it converts a Gaussian beam with a circular beam spot into a flat-top beam with a rectangular beam spot. Here, a Gaussian beam is a beam whose spatial intensity distribution of laser light follows a Gaussian distribution. A flat-top beam is a beam in which the energy intensity in the cross-section of the laser light is uniform, and the intensity of the laser light decreases sharply at the edges of the beam spot. For example, the beam shaper 12 is a diffractive optical element that utilizes the diffraction phenomenon of light to spatially split the laser beam. The galvanometer mirror 13 is configured to rotate around two intersecting axes and reflects the laser beam L1 at any angle. The fθ lens 14 focuses the laser beam L1 from the galvanometer mirror 13 onto the adhesive layer Ad of the support substrate Su.

[0020] Also, the substrate holding unit 3 holds the support substrate Su on which the semiconductor element El is supported. The substrate holding unit 3 supports the support substrate Su on which the semiconductor element El is supported with the surface supporting the semiconductor element El facing downward (in the Z2 direction). The substrate holding unit 3 has an opening 31. The laser beam L1 is irradiated from the laser beam irradiation unit 1 to the support substrate Su held by the substrate holding unit 3 through the opening 31. The substrate holding unit 3 is configured to be relatively movable with respect to the fθ lens 14 in the X, Y, and Z directions by the movement mechanism 6.

[0021] The alignment camera 4 uses, as the illumination light L2, a wavelength that is different from the wavelength of the laser beam L1 and that does not cause peeling of the semiconductor element El from the support substrate Su, and is configured to image the alignment mark M provided on the support substrate Su. For example, as the wavelength of the illumination light L2, light with a wavelength of 660 nm that is less likely to generate gas components in the adhesive layer Ad is used.

[0022] The control unit 2 includes, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and GPU (Graphics Processing Unit) as processors, and performs various controls and calculations by executing programs (software). The control unit 2 is also provided with storage 21 for storing data, and the storage 21 stores board data for the support substrate Su. The storage 21 includes, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive). Here, the board data consists of the thickness t of the support substrate Su, the refractive index n1 of the support substrate Su with respect to the wavelength of the laser light L1, and the refractive index n2 of the support substrate Su with respect to the wavelength of the illumination light L2 of the alignment camera 4. In the following description of this embodiment, it will be assumed that board data D1 and board data D2 are stored in the storage 21. Here, substrate data D1 is the substrate data for the support substrate Su, where the thickness of the support substrate Su is t11, the refractive index of the support substrate Su with respect to the wavelength of the laser light L1 is n11, and the refractive index of the support substrate Su with respect to the wavelength of the illumination light L2 is n21. Substrate data D2 is the substrate data for the support substrate Su, where the thickness of the support substrate Su is t12, the refractive index of the support substrate Su with respect to the wavelength of the laser light L1 is n12, and the refractive index of the support substrate Su with respect to the wavelength of the illumination light L2 is n22. Hereafter, the substrate data thickness t11 will be the portion of the support substrate Su thickness t stored in storage 21 that pertains to substrate data D1. Similarly, the substrate data thickness t12 will be the portion of the support substrate Su thickness t stored in storage 21 that pertains to substrate data D2.

[0023] The laser displacement meter 5 is positioned on the adhesive layer Ad side of the support substrate Su and is configured to measure the distance to the support substrate Su. Here, the distance between the laser displacement meter 5 and the suction surface O1 of the support substrate Su of the substrate holding unit 3 is measured in advance. The difference between the distance between the laser displacement meter 5 and the suction surface O1 of the support substrate Su of the substrate holding unit 3 and the distance to the interface O2 between the support substrate Su and the adhesive layer Ad is the thickness t of the support substrate Su. Therefore, by measuring the distance to the interface O2 between the support substrate Su and the adhesive layer Ad using the laser displacement meter 5, the semiconductor element transfer apparatus 100 is configured to obtain the thickness t of the support substrate Su. Hereinafter, the thickness t of the support substrate Su measured by the laser displacement meter 5 will be referred to as the measured thickness t2.

[0024] (How to adjust the laser focus) Next, the laser focus adjustment method of this embodiment will be described with reference to Figures 1 to 5. The following description will be performed by the semiconductor element transfer apparatus 100 according to the laser focus adjustment method flow shown in Figure 2.

[0025] Before the laser focus adjustment procedure is executed, the positions of the fθ lens 14 and the alignment camera 4 are pre-adjusted. Specifically, the support substrate Su is irradiated with laser light L1, and the positions of the fθ lens 14 and the support substrate Su are adjusted so that the energy density of the laser light L1 that has passed through the support substrate Su is appropriate in the adhesive layer Ad. At a distance at which the adhesive layer Ad can be irradiated with laser light L1 of appropriate energy density, the focus of the alignment camera 4 is adjusted to match the alignment mark M provided on the surface of the support substrate Su on the adhesive layer Ad side. In this embodiment, the positions of the fθ lens 14 and the alignment camera 4 are pre-adjusted using the support substrate Su of substrate data D1.

[0026] First, in step S1, as shown in Figure 2, the semiconductor device transfer apparatus 100 in Figure 1 obtains the measured thickness t2 of the support substrate Su using the laser displacement meter 5. That is, the control unit 2 obtains the actual thickness of the support substrate Su held by the substrate holding unit 3 as the measured thickness t2 of the support substrate Su. After that, the process proceeds to step S2.

[0027] Next, in step S2, the semiconductor device transfer apparatus 100 in Figure 1 adjusts the camera height h of the alignment camera 4 that images the alignment marks M provided on the support substrate Su, and acquires the position where the focus of the alignment camera 4 matches the alignment marks M provided on the support substrate Su as the measured camera height h1 of the alignment camera 4. Here, the focus adjustment of the alignment camera 4 is performed by moving the substrate holding part 3 in the Z direction using the moving mechanism 6. Note that the camera height h is an example of the "focus position" in the claims. After that, the process proceeds to step S3.

[0028] Next, in step S3, the control unit 2 calculates the camera height h2 of the alignment camera 4 from the substrate data thickness t11, which is the thickness t of the support substrate Su, and the refractive index n21 with respect to the illumination wavelength, which are recorded in advance in the storage 21 as substrate data D1. Specifically, as shown in Figure 3, the sum of the camera height h2 of the alignment camera 4 and the substrate data thickness t11 of the support substrate Su is equal to the sum of the focal length F of the lens 41 of the alignment camera 4 and the focus shift d due to the illumination light L2 passing through the support substrate Su. Furthermore, the focus shift d from the focus position in the air due to the illumination light L2 passing through the support substrate Su can be calculated by the following formula (1).

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[0029] In step S4, the control unit 2 determines whether the difference between the measured camera height h1 of the alignment camera 4 acquired in step S2 and the camera height h2 calculated in step S3 is within an acceptable range. Here, the camera height h2 of the alignment camera 4 is uniquely determined by the focal length F of the lens 41 of the alignment camera 4 used, the thickness t11 of the support substrate Su, and the refractive index n21 of the support substrate Su with respect to the illumination wavelength. Therefore, if the correct substrate data is set for the support substrate Su used in the semiconductor element transfer apparatus 100, the difference between the measured camera height h1 of the alignment camera 4 acquired in step S2 and the camera height h2 calculated in step S3 will be within an acceptable range (for example, within the range of errors based on the manufacturing error or measurement error of the support substrate Su). If it is determined to be within an acceptable range, the substrate data D1 set for the support substrate Su being used is determined to be correct. Then, the process proceeds to step S8. If it is determined to be outside an acceptable range (if the set substrate data is incorrect), the process proceeds to step S5.

[0030] In step S5, the control unit 2 displays a warning on a display unit (not shown) indicating that there is a discrepancy in the board data settings. The process then proceeds to step S6.

[0031] In step S6, the control unit 2 controls the distance between the laser beam irradiation unit 1 that irradiates the support substrate Su with the laser beam L1 and the support substrate Su, based on the refractive index of the support substrate Su with respect to the wavelength of the laser beam L1 irradiated onto the support substrate Su from the side opposite to the surface supporting the semiconductor element El, and the thickness of the support substrate Su.

[0032] Here, the step of adjusting the distance between the laser beam irradiation unit 1 and the support substrate Su in step S6 is a step of adjusting the distance between the laser beam irradiation unit 1 and the adhesive layer Ad based on the refractive index n1 of the support substrate Su with respect to the wavelength of the laser beam L1 and the thickness t of the support substrate Su. More specifically, the control unit 2 adjusts the distance between the fθ lens 14 and the adhesive layer Ad of the support substrate Su.

[0033] Here, the control unit 2 adjusts the distance between the laser beam irradiation unit 1 and the support substrate Su based on the measured thickness t1 of the support substrate Su measured in step S1, the measured camera height h1 of the alignment camera 4, and the refractive index n2 of the support substrate Su with respect to the illumination wavelength of the illumination light L2. Specifically, the control unit 2 calculates the refractive index n2 of the support substrate Su with respect to the illumination wavelength of the illumination light L2 based on the measured thickness t1 of the support substrate Su measured in step S1 and the measured camera height h1 of the alignment camera 4. Subsequently, the control unit 2 searches the substrate data stored in the storage 21 for substrate data that matches the measured thickness t1 of the support substrate Su and the calculated refractive index n2 of the support substrate Su with respect to the wavelength of the illumination light L2, and obtains the refractive index n1 with respect to the wavelength of the laser light L1 according to the searched substrate data. Specifically, if the support substrate Su is the support substrate Su of substrate data D2 and not the support substrate Su of substrate data D1, the measured thickness t2 will be close to the substrate data thickness t12 stored in substrate data D2, and the refractive index n2 of the support substrate Su with respect to the illumination wavelength of the illumination light L2 will also be close to the refractive index n22 stored in substrate data D2. Therefore, based on substrate data D2, the refractive index n12 of the support substrate Su being used with respect to the wavelength of the laser light L1 is obtained.

[0034] Furthermore, the step of adjusting the distance between the laser beam irradiation unit 1 and the support substrate Su in step S6 includes adjusting the size of the laser spot of the laser beam L1 on the surface supporting the semiconductor element El by adjusting the distance between the laser beam irradiation unit 1 and the support substrate Su. Specifically, the laser spot is adjusted to a size such that a laser beam L1 with an appropriate energy density can be irradiated onto the adhesive layer Ad on the surface of the support substrate Su facing the adhesive layer Ad. In this embodiment, the intensity of the laser beam L1 is pre-adjusted so that a laser beam L1 with an appropriate energy density is irradiated when the size of one side of the square beam spot is r (see Figure 4).

[0035] Here, as shown in Figure 4, the control unit 2 adjusts the distance between the fθ lens 14 and the adhesive layer Ad based on the measured thickness t2 of the support substrate Su obtained in step S1 and the refractive index n12 for the laser light L1 obtained based on the substrate data D2. Specifically, the control unit 2 calculates the laser focus distance, which is the distance between the fθ lens 14 and the adhesive layer Ad such that the size of the laser spot of the laser light L1 after passing through the support substrate Su becomes an appropriate size r, using the following formula (2). Specifically, the control unit 2 calculates the laser focus distance deviation f when passing through the support substrate Su, using the laser focus distance (position A) where the laser spot size r is appropriate in air as a reference. The deviation f of the laser focus distance can be obtained using the following formula (2).

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[0036] Furthermore, Figures 5(a) and 5(b) show the state in which laser light L1 is incident on the support substrate Su of substrate data D1 and the support substrate Su of substrate data D2, respectively. Here, based on formula (2), the focus distance shift f1 is calculated for the support substrate Su of substrate data D1, and the focus distance shift f2 is calculated for the support substrate Su of substrate data D2. Also, in Figure 5, the position A that results in an appropriate laser spot size r in air is shown aligned in the Z direction. As described above, the semiconductor element transfer apparatus 100 has the distance between the fθ lens 14 and the support substrate Su adjusted in advance based on the substrate data D1. Therefore, by moving the support substrate holding part 3 in the Z2 direction by the distance f2-f1 shown in Figure 5(a), the distance between the fθ lens 14 and the adhesive layer Ad is adjusted so that the distance between the fθ lens 14 and the adhesive layer Ad falls within the range of the calculated laser focus distance. After that, the process proceeds to step S7.

[0037] In step S7, the alignment camera 4 is moved in the Z direction using the movement mechanism 6 to focus on the alignment mark M. This adjusts the distance between the fθ lens 14 and the support substrate Su so that when the alignment camera 4 is in focus on the alignment mark M provided on the support substrate Su of the substrate data D2, the distance between the fθ lens 14 and the support substrate Su is the distance at which the laser beam L1 is properly irradiated. The process then proceeds to step S8.

[0038] In step S8, the semiconductor element El is transferred by irradiating the support substrate Su with laser light L1. That is, the laser light irradiation unit 1 irradiates the support substrate Su, held by the substrate holding unit 3, with laser light L1 from the side opposite to the side supporting the semiconductor element El, via the galvanometer mirror 13 and the fθ lens 14. The laser light L1 is irradiated by the galvanometer mirror 13 and the fθ lens 14 onto the adhesive layer Ad between the semiconductor element El and the support substrate Su. As a result, the semiconductor element El is peeled off the support substrate Su and transferred from the support substrate Su to the substrate on the target table (not shown). After that, the processing flow of the laser focus adjustment method is terminated.

[0039] (Effects of this embodiment) Next, the effects of this embodiment will be described.

[0040] In the semiconductor element transfer apparatus 100 of this embodiment, as described above, the control unit 2 is configured to perform the step of adjusting the distance between the laser beam irradiation unit 1 and the support substrate Su based on the refractive index n1 of the support substrate Su with respect to the wavelength of the laser beam L1 and the thickness t of the support substrate Su. Furthermore, in the irradiation direction of the laser beam L1, the position where the laser beam L1 is focused after passing through the support substrate Su is determined by the refractive index n1 of the support substrate Su with respect to the wavelength of the laser beam L1 and the thickness t of the support substrate Su. Therefore, by configuring the control unit 2 to control the distance between the laser beam irradiation unit 1 and the support substrate Su based on the refractive index n1 of the support substrate with respect to the wavelength of the laser beam L1 and the thickness t of the support substrate, it is possible to suppress the occurrence of a shift in the energy density of the laser beam L1 on the surface of the support substrate Su that supports the semiconductor element El due to a change in the material or thickness of the support substrate Su. As a result, even if the material or thickness of the support substrate Su is changed, it is possible to irradiate the surface of the support substrate Su that supports the semiconductor element El with laser beam L1 of an appropriate energy density.

[0041] Furthermore, in this embodiment, as described above, step S6, which adjusts the distance between the laser beam irradiation unit 1 and the support substrate Su, includes the step of adjusting the size of the laser spot of the laser beam L1 on the surface supporting the semiconductor element El by adjusting the distance between the laser beam irradiation unit 1 and the support substrate Su. Here, the size of the laser spot of the focused laser beam L1 gradually decreases up to the position where the laser beam L1 is focused, and gradually increases beyond the position where the laser beam L1 is focused, so the size of the laser spot of the laser beam L1 changes according to the distance from the laser beam irradiation unit 1. Also, if the intensity of the irradiated laser beam L1 is not changed, the total energy of the laser beam L1 irradiated to each laser spot of different sizes is equal regardless of the size of the laser spot. For this reason, the energy density of the laser beam L1 at the laser spot increases as the size of the laser spot decreases. Therefore, the energy density of the laser beam L1 on the surface of the support substrate Su that supports the semiconductor element El depends on the size of the laser spot on the surface of the support substrate Su that supports the semiconductor element El. Therefore, by adjusting the size of the laser spot of the laser beam L1 on the surface of the support substrate Su that supports the semiconductor element El, the laser beam L1 can be irradiated with an appropriate energy density on the surface of the support substrate Su that supports the semiconductor element El.

[0042] Furthermore, in this embodiment, as described above, the support substrate Su is provided with an adhesive layer Ad for adhesively supporting the semiconductor element El, and step S6 for adjusting the distance between the laser light irradiation unit 1 and the support substrate Su is a step of adjusting the distance between the laser light irradiation unit 1 and the adhesive layer Ad based on the refractive index n1 of the support substrate Su with respect to the wavelength of the laser light L1 and the thickness t of the support substrate Su. Step S6 for adjusting the distance between the laser light irradiation unit 1 and the support substrate Su includes the step of calculating the range of the laser focus distance, which is the distance between the fθ lens 14 that focuses the laser light L1 contained in the laser light irradiation unit 1 and the adhesive layer Ad, based on the refractive index n1 of the support substrate Su with respect to the wavelength of the laser light L1 and the thickness t of the support substrate Su, and the step of adjusting the distance between the fθ lens 14 and the adhesive layer Ad so that the distance between the lens and the adhesive layer Ad falls within the calculated range of the laser focus distance. This allows the laser focus distance to be calculated as the distance at which a laser beam L1 of appropriate energy density can be irradiated onto the adhesive layer Ad, based on the refractive index n1 of the support substrate Su with respect to the wavelength of the laser beam L1 and the thickness t of the support substrate Su. Furthermore, since the distance between the laser beam irradiation unit 1 and the adhesive layer Ad is adjusted so that the adhesive layer Ad is within the range of the calculated laser focus distance, the adhesive layer Ad can be positioned at a distance at which a laser beam L1 of appropriate energy density is irradiated. As a result, even if the material or thickness t of the support substrate Su is changed, a laser beam L1 of appropriate energy density can be irradiated onto the adhesive layer Ad of the support substrate in order to properly form a blister, which is a bulge in the adhesive layer Ad for peeling off the semiconductor element El.

[0043] Furthermore, in this embodiment, as described above, a wavelength different from the wavelength of the laser light L1 is used as the illumination wavelength so as not to cause peeling of the semiconductor element El from the support substrate Su, and the embodiment further includes step S2 of adjusting the camera height h of the alignment camera 4 that images the alignment mark M provided on the support substrate Su. Step S6 of adjusting the distance between the laser light irradiation unit 1 and the support substrate Su includes adjusting the distance between the laser light irradiation unit 1 and the support substrate Su based on the camera height h, the refractive index n2 of the support substrate Su with respect to the illumination wavelength, and the thickness t of the support substrate Su. As a result, by using a wavelength as the illumination wavelength so as not to cause peeling of the semiconductor element El from the support substrate Su, it is possible to obtain information for adjusting the distance between the laser light irradiation unit 1 and the support substrate Su while suppressing peeling of the semiconductor element El.Therefore, the distance between the laser light irradiation unit 1 and the support substrate Su can be adjusted without affecting the semiconductor element El supported on the support substrate.

[0044] [Differentiation] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and further includes all modifications (exceptions) within the meaning and scope equivalent to the claims.

[0045] For example, in the above embodiment, in step S6, an example was shown in which the distance between the fθ lens 14 and the support substrate Su is adjusted by moving the substrate holding part 3 that holds the support substrate Su in order to adjust the distance between the fθ lens 14 and the support substrate Su, but the present invention is not limited to this. In the present invention, for example, the distance between the fθ lens 14 and the support substrate Su may be adjusted by moving the fθ lens 14. Note that if the fθ lens 14 is moved in step S6, the distance between the alignment camera 4 and the support substrate Su does not change, so step S7 can be omitted. However, in order to stabilize the shape of the laser beam L1, it is preferable to fix the position of the fθ lens 14.

[0046] Furthermore, although the above embodiment shows an example in which the thickness t of the support substrate Su is measured using the laser displacement meter 5 in step S1, the present invention is not limited thereto. In the present invention, for example, the thickness t of the support substrate Su may be measured using the laser displacement meter 5 after it has been determined in step S4 that it is not within the acceptable range, and before the distance between the fθ lens 14 and the support substrate Su is adjusted in step S6.

[0047] Furthermore, in the above embodiment, an example was shown in which the thickness t of the support substrate Su is measured using a laser displacement meter 5 in step S1, but the present invention is not limited thereto. In the present invention, the thickness t of the support substrate Su may be measured using a device other than the laser displacement meter 5.

[0048] Furthermore, although the above embodiment shows an example in which the laser beam L1 is formed into a rectangular flat top using a beam shaper, the present invention is not limited thereto. In the present invention, the laser beam L1 may be used as a circular Gaussian beam without using the beam shaper 12.

[0049] Furthermore, although the above embodiment shows an example in which two board data, board data D1 and board data D2, are stored in the storage 21 as board data, the present invention is not limited to this. Three or more board data may be stored in the storage 21.

[0050] Furthermore, in the above embodiment, the laser beam irradiation unit 1 is shown to irradiate the support substrate Su held by the substrate holding unit 3 with laser beam L1 from the side opposite to the side supporting the semiconductor element El, via the galvanometer mirror 13 and the fθ lens 14. However, the present invention is not limited to this. The galvanometer mirror 13 may be omitted, and an objective lens or the like may be used instead of the fθ lens 14. [Explanation of Symbols]

[0051] 1. Laser beam irradiation area 11 Laser light source 12 Beam Shaper 13 Galvano Mirror 14 fθ lens 2 Control Unit 3 Board holding part 4 Alignment Cameras 5. Laser displacement sensor 100 Semiconductor element transfer apparatus El semiconductor element L1 laser light L2 illumination light M Alignment Mark Su support substrate Ad adhesive layer

Claims

1. A step of adjusting the distance between the laser beam irradiation unit that irradiates the support substrate and the support substrate based on the refractive index of the support substrate with respect to the wavelength of laser light irradiated onto the support substrate from the side opposite to the surface supporting the semiconductor element, and the thickness of the support substrate, A semiconductor element transfer method comprising the steps of adjusting the distance between the laser light irradiation unit and the support substrate, and then transferring the semiconductor element by irradiating the support substrate with the laser light.

2. The semiconductor element transfer method according to claim 1, wherein the step of adjusting the distance between the laser light irradiation unit and the support substrate includes the step of adjusting the size of the laser spot of the laser light on the surface supporting the semiconductor element by adjusting the distance between the laser light irradiation unit and the support substrate.

3. The support substrate is provided with an adhesive layer for adhesively supporting the semiconductor element. The step of adjusting the distance between the laser light irradiation unit and the support substrate is a step of adjusting the distance between the laser light irradiation unit and the adhesive layer based on the refractive index of the support substrate with respect to the wavelength of the laser light and the thickness of the support substrate. The step of adjusting the distance between the laser beam irradiation unit and the support substrate is: A step of calculating the range of the laser focus distance, which is the distance between the lens that focuses the laser light contained in the laser light irradiation section and the adhesive layer, based on the refractive index of the support substrate with respect to the wavelength of the laser light and the thickness of the support substrate, A semiconductor element transfer method according to claim 1, comprising the step of adjusting the distance between the lens and the adhesive layer so that the distance between the lens and the adhesive layer falls within the calculated range of the laser focus distance.

4. The procedure further includes using an illumination wavelength that is different from the wavelength of the laser light and that does not cause the semiconductor element to peel off from the support substrate, and adjusting the focus position of an alignment camera that images the alignment marks provided on the support substrate. The semiconductor element transfer method according to claim 1, wherein the step of adjusting the distance between the laser light irradiation unit and the support substrate includes adjusting the distance between the laser light irradiation unit and the support substrate based on the focus position, the refractive index of the support substrate with respect to the illumination wavelength, and the thickness of the support substrate.

5. A support substrate on which a semiconductor element is supported is positioned on the opposite side from the surface supporting the semiconductor element, and a laser beam irradiation unit irradiates focused laser light toward the support substrate, The system includes a control unit that controls the distance between the laser beam irradiation unit and the support substrate, A semiconductor element transfer apparatus, wherein the control unit is configured to control the distance between the laser light irradiation unit and the support substrate based on the refractive index of the support substrate with respect to the wavelength of the laser light and the thickness of the support substrate.

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