Laser lift-off method, method for manufacturing a receptor substrate, laser lift-off apparatus, photomask, and transfer apparatus

Abstract

The present invention is a laser lift-off method in which an object to be transferred is transferred from a first substrate provided with the object to be transferred to a second substrate using laser lift-off, wherein the laser lift-off method comprises a collective transfer step for collectively irradiating the interfaces between a plurality of the objects to be transferred and the first substrate with a laser, separating the plurality of objects to be transferred from the first substrate, and collectively transferring said objects to the second substrate. In the collective transfer step, only a portion of the interface between each of the plurality of the objects to be transferred and the first substrate is exposed to the laser. As a result, it is possible to provide a laser lift-off method capable of minimizing the incidence of damage to the objects to be transferred when said objects are transferred.

Description

Technical Field

[0001] The present invention relates to a laser lift-off method, a method for manufacturing a receptor substrate, a laser lift-off apparatus, and a photomask.

Background Art

[0002] In recent years, nitride semiconductor optical devices have come to be used as backlights for liquid crystal displays and as displays for signage.

[0003] Optical devices are produced in large quantities by semiconductor processes on, for example, sapphire substrates. When producing a 4-inch display substrate using LEDs with a size of 100 μm square or less, called micro-LEDs, several million micro-LEDs are required. Micro-LEDs, which are tiny devices with a size of several tens of μm, are separated from the sapphire substrate, which is an epi-substrate, and then used.

[0004] As a separation method, it is common to bond a support substrate as a donor precursor substrate to an optical device arranged on a sapphire substrate, and separate the optical device from the sapphire substrate by laser lift-off (LLO). As a result, a donor substrate with a large number of optical devices arranged on its surface can be obtained.

[0005] Such a method is not limited to those related to optical devices, and can also be applied to manufacturing a donor substrate on which a plurality of transfer objects such as fine semiconductor devices are arranged on the surface.

[0006] In addition, the transfer object on the donor substrate is transferred onto a receptor substrate so as to be arranged corresponding to, for example, the circuit board of a product, and can be transferred from this receptor substrate to another substrate such as the circuit board of the product by a stamping method.

[0007] For example, Patent Document 1 proposes a method of accurately transferring a transfer object on a donor substrate to a receptor substrate using laser irradiation.

[0008] Now, the laser lift-off method is a technique in which a substrate (first substrate) having an object to be transferred is irradiated with a laser at the interface between the object to be transferred and the first substrate to peel the object to be transferred from the first substrate, and the peeled object to be transferred is transferred to another substrate (second substrate).

[0009] Such a laser lift-off method is roughly classified into gap-laser lift-off (Gap-LLO) and contact laser lift-off (Contact-LLO). Hereinafter, these methods will be schematically described with reference to FIGS. 21 and 22.

[0010] In Gap-LLO, first, as shown in FIG. 21(a) for example, a first substrate (e.g., a sapphire substrate) 1 having an object to be transferred (e.g., a micro LED chip) 10 and a second substrate (e.g., a quartz substrate) 2 having an adhesive layer 3 on its surface are opposed to each other with a space, i.e., a gap, opened between the object to be transferred 10 and the adhesive layer 3. In this state, a laser 20R is irradiated from a laser oscillator 110 through the surface of the first substrate 1 opposite to the object to be transferred 10 to the interface 11 between the first substrate 1 and the plurality of objects to be transferred 10. Generally, the laser 20R is irradiated one by one in order over the entire surface of the interface 11 between each object to be transferred 10 and the first substrate 1.

[0011] For example, in the case of the first substrate 1 which is a sapphire substrate having a plurality of objects to be transferred 10 including a GaN layer at the interface 11, when irradiated with the laser 20R, the GaN layer decomposes (ablation). When the bonding force (adhesive force, joining force, etc.) between the object to be transferred 10 and the first substrate 1 weakens due to ablation, the object to be transferred 10 is peeled from the first substrate 1. Further, due to the decomposition of the GaN layer, a gas (e.g., nitrogen gas) is generated. Due to the pressure of this gas, the peeled object to be transferred 10 obtains a propulsive force toward the second substrate 2, moves through the space between the first substrate 1 and the second substrate 2, and reaches the adhesive layer 3 on the second substrate 2. In this way, the object to be transferred 10 is transferred onto the second substrate 2.

[0012] Next, as shown in FIG. 21(b), the first substrate 1 is removed. Thereby, the transfer of the transfer object 10 from the first substrate 1 to the second substrate 2 is completed.

[0013] Contact-LLO is the same as Gap-LLO except that when irradiating the laser 20R, as shown in FIG. 22(a), the first substrate 1 having the transfer object 10 and the second substrate 2 having the adhesive layer 3 on the surface are opposed to each other with the transfer object 10 and the adhesive layer 3 in contact with each other. After the irradiation of the laser 20R, by removing the first substrate 1 as shown in FIG. 22(b), the transfer of the transfer object 10 from the first substrate 1 to the second substrate 2 is completed.

Prior Art Documents

Patent Documents

[0014]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0015] Conventionally, due to transfer by Gap-LLO, the transfer object may be cracked. Even with Contact-LLO, chipping may occur in the transfer object.

[0016] The present invention has been made to solve the above problems, and provides a laser lift-off method capable of suppressing the occurrence of breakage of a transfer object during transfer, a method for manufacturing a receptor substrate capable of manufacturing a receptor substrate having a transfer object without breakage, a laser lift-off apparatus capable of suppressing the occurrence of breakage of a transfer object during transfer, and a photomask for laser lift-off capable of suppressing the occurrence of breakage of a transfer object during transfer.

Means for Solving the Problems

[0017] In order to solve the above problems, the present invention provides a laser lift-off method for transferring an object to be transferred from a first substrate having the object to be transferred to a second substrate by laser lift-off, comprising: a batch transfer step of irradiating a laser collectively on the interfaces between a plurality of the objects to be transferred and the first substrate to peel the plurality of objects to be transferred from the first substrate and transfer them collectively to the second substrate; provided is a laser lift-off method in which, in the batch transfer step, the laser is irradiated only on a part of the interface between each of the plurality of objects to be transferred and the first substrate.

[0018] Here, "laser irradiation of only a part" means that the laser irradiation at each interface is a part of each interface. That is, it is sufficient that the laser irradiation at each interface is a part of each interface, and laser irradiation may be performed on a region where no object to be transferred exists simultaneously with this irradiation. Therefore, a form in which the laser is also irradiated on a region where no object to be transferred exists, such as between adjacent objects to be transferred as illustrated in FIGS. 4, 5, and 6 described later, is also included in the present invention.

[0019] In the batch transfer step, by irradiating the laser only on a part of the interface between each of the plurality of objects to be transferred and the first substrate (hereinafter also referred to as partial irradiation), the impact generated during laser lift-off can be reduced, and the occurrence of breakage such as cracking and chipping of the object to be transferred during transfer can be suppressed.

[0020] Preferably, before the batch transfer step, a preliminary irradiation step is further included in which the laser is irradiated on the interface between each of the plurality of objects to be transferred and the first substrate with energy smaller than the energy irradiated in the batch transfer step and with energy at which the object to be transferred does not peel from the first substrate.

[0021] By performing such a preliminary irradiation step, in the batch transfer step, the impact on the transfer target can be further reduced, and the shift of the transfer position of the transfer target can be suppressed. Further, in the batch transfer step, when a material having a crystal structure such as a GaN layer is used as the ablation layer, the generation of cracks can be suppressed, and the generation of residues can be suppressed.

[0022] In this case, in the preliminary irradiation step, it is particularly preferable to irradiate the laser only on a part of the interface between each of the plurality of transfer targets and the first substrate.

[0023] By performing partial irradiation also in the preliminary irradiation step, when a material having a crystal structure such as a GaN layer is used as the ablation layer, the generation of cracks can be further suppressed, and thus the generation of residues can be suppressed.

[0024] For example, the preliminary irradiation step can be performed 1 to 4 times.

[0025] The number of times of the preliminary irradiation step is not particularly limited, but by performing it a plurality of times, it becomes easier to control the impact applied to the transfer target during laser lift-off while appropriately maintaining the laser lift-off speed.

[0026] For example, in each of the preliminary irradiation step and the batch transfer step, it is preferable to perform laser irradiation such that the irradiation area of the laser is 10 to 60% of the area of the interface between each of the plurality of transfer targets and the first substrate.

[0027] If the irradiation area in the partial irradiation in each of the preliminary irradiation step and the batch transfer step is within the range of 10 to 60% of the area of the interface between each of the plurality of transfer targets and the first substrate, the transfer target can be efficiently transferred from the first substrate to the second substrate, and a margin can be provided for the laser irradiation error.

[0028] It is preferable to change the irradiation area of the laser between the preliminary irradiation step and the batch transfer step.

[0029] By changing the laser irradiation area between the preliminary irradiation step and the batch transfer step, the generation of unirradiated portions of the laser between the transfer object and the first substrate can be suppressed, and when a material having a crystal structure such as a GaN layer is used as the ablation layer, the generation of cracks can be suppressed.

[0030] It is preferable to perform the preliminary irradiation step and the batch transfer step so that there is no overlapping portion of the laser irradiation area, or so that the overlapping portion of the laser irradiation area is 10% or less of the area of the interface between each of the plurality of transfer objects and the first substrate.

[0031] The irradiation areas in the preliminary irradiation step and the batch transfer step may overlap, and by making the overlapping portion 10% or less, excessive alteration of the transfer object can be suppressed, and a margin can be provided for laser irradiation error.

[0032] The laser can be irradiated to 40 to 100% of the area of the interface between each of the plurality of transfer objects and the first substrate in total of the preliminary irradiation step and the batch transfer step.

[0033] By irradiating the laser to 40% or more of the area of the interface between each of the plurality of transfer objects and the first substrate in total of the preliminary irradiation step and the batch transfer step, transfer can be performed more efficiently. Also, in total of the preliminary irradiation step and the batch transfer step, the laser may be irradiated to the entire area of the interface between each of the plurality of transfer objects and the first substrate, that is, 100%.

[0034] For example, the output of the laser may be changed between the preliminary irradiation step and the batch transfer step.

[0035] For example, by changing the output of the laser between the preliminary irradiation step and the batch transfer step, the irradiation energy of the laser in the preliminary irradiation step can be made smaller than the irradiation energy in the batch transfer step.

[0036] Alternatively, prepare a photomask including a first portion having a first laser transmittance and a second portion having a second laser transmittance lower than the first laser transmittance, In the preliminary irradiation step, irradiate the laser through the second portion of the photomask, In the batch transfer step, the laser irradiation may be performed through the first portion of the photomask.

[0037] In this way, since it is not necessary to change the output of the laser between the preliminary irradiation step and the batch transfer step, it is advantageous for mass production.

[0038] In the batch transfer step, it is preferable to perform laser irradiation so that the laser irradiation area becomes 40 to 90% of the area of the interface between each of the plurality of objects to be transferred and the first substrate.

[0039] If the area of the laser irradiation area in the batch transfer step is within the above range, it is possible to suppress the occurrence of breakage of the object to be transferred while maintaining the transfer efficiency.

[0040] In the batch transfer step, the laser may be irradiated so that a plurality of irradiation areas where the laser is irradiated are formed on the interface between each of the plurality of objects to be transferred and the first substrate.

[0041] The form of partial irradiation is not particularly limited. For example, a plurality of irradiation areas may be formed.

[0042] In this case, for example, in the batch transfer step, the laser can be irradiated so that the irradiation area has at least one shape selected from the group consisting of a circular shape, an elliptical shape, and a polygonal shape.

[0043] The shape of the irradiation area is not particularly limited. For example, it can be a circular shape, an elliptical shape, or a polygonal shape.

[0044] Alternatively, in the batch transfer process, the laser can be irradiated so that the irradiation region has a linear shape.

[0045] The irradiation region may have a line shape.

[0046] For example, in the batch transfer process, the laser can be irradiated so that the irradiation region has a rectangular or linear shape and the longitudinal direction of the irradiation region substantially coincides with the longitudinal direction of the transfer object.

[0047] Alternatively, in the batch transfer process, the laser may be irradiated so that the irradiation region has a rectangular or linear shape and the longitudinal direction of the irradiation region substantially coincides with the short-side direction of the transfer object.

[0048] Alternatively, in the batch transfer process, the laser may be irradiated so that the irradiation region has a rectangular or linear shape and the irradiation region straddles the adjacent transfer objects.

[0049] Thus, the arrangement of the plurality of irradiation regions with respect to the transfer object is not particularly limited.

[0050] In the batch transfer process, the laser can also be irradiated so that a plurality of non-irradiation regions where the laser is not irradiated are formed at the interfaces of the plurality of transfer objects with the first substrate.

[0051] Partial irradiation may be performed so that a plurality of non-irradiation regions are formed.

[0052] In this case, for example, in the batch transfer process, the laser can be irradiated so that the non-irradiation region has at least one shape selected from the group consisting of a circular shape, an elliptical shape, and a polygonal shape.

[0053] The shape of the non-irradiation region is not particularly limited, but can be, for example, a circular shape, an elliptical shape, or a polygonal shape.

[0054] Alternatively, in the batch transfer step, the laser may be irradiated so that the non-irradiation region has a linear shape.

[0055] The non-irradiation region may have a linear shape.

[0056] For example, in the batch transfer step, the laser can be irradiated so that the non-irradiation region has a rectangular or linear shape, and the longitudinal direction of the non-irradiation region substantially coincides with the longitudinal direction of the transfer object.

[0057] Alternatively, in the batch transfer step, the laser may be irradiated so that the non-irradiation region has a rectangular or linear shape, and the longitudinal direction of the non-irradiation region substantially coincides with the short-side direction of the transfer object.

[0058] Alternatively, in the batch transfer step, the laser may be irradiated so that the non-irradiation region has a rectangular or linear shape, and the non-irradiation region straddles the adjacent transfer objects.

[0059] Thus, the arrangement of the plurality of non-irradiation regions with respect to the transfer object is not particularly limited.

[0060] For example, as the transfer object, those selected from the group consisting of semiconductor chips, LED chips, resin material films, and inorganic films can be transferred.

[0061] The transfer object in the present invention is not particularly limited, but for example, these objects can be used as the transfer object.

[0062] Further, in the present invention, there is provided a method for manufacturing a receptor substrate on which a plurality of transfer objects are arranged, a step of preparing a donor substrate provided with the plurality of transfer objects and a receptor precursor substrate; a step of transferring the transfer object from the donor substrate to the receptor precursor substrate by laser lift-off to obtain a receptor substrate including In the step of obtaining the receptor substrate, a method for manufacturing a receptor substrate is provided, in which a plurality of transfer objects are laser lifted off from the donor substrate as the first substrate to the receptor precursor substrate as the second substrate by the laser lift-off method of the present invention.

[0063] According to the method for manufacturing a receptor substrate of the present invention, since the transfer object is transferred by the laser lift-off method of the present invention to obtain the receptor substrate, a receptor substrate having a transfer object without damage can be manufactured. In addition, the production yield of the receptor substrate can be improved.

[0064] Further, in the present invention, there is provided a laser lift-off apparatus for transferring a transfer object from a first substrate having the transfer object to a second substrate by laser lift-off, a laser oscillator, a stage for supporting the first substrate and the second substrate to face each other, a photomask disposed between the optical paths of the laser oscillator and the stage, and comprising the laser oscillator, the photomask and the stage are configured to irradiate the laser from the laser oscillator collectively to the interface between the plurality of transfer objects and the first substrate, the photomask has a pattern formed in a shape that irradiates the laser from the laser oscillator only to a part of the interface between each of the plurality of transfer objects and the first substrate, and a laser lift-off apparatus is provided.

[0065] In the laser lift-off apparatus of the present invention, when a plurality of transfer objects are transferred to the second substrate collectively by laser lift-off, partial irradiation can be performed on each of the plurality of transfer objects. Thereby, the impact generated during laser lift-off can be reduced, and the occurrence of damage such as cracking and chipping of the transfer object during transfer can be suppressed.

[0066] The laser is further configured to be able to switch between the energy for irradiating the interface between the plurality of objects to be transferred and the first substrate, the energy at which the object to be transferred does not peel off from the first substrate, and the energy at which the object to be transferred peels off from the first substrate, which is preferable.

[0067] By using such a device, partial irradiation can be performed in multiple stages, and when transferring a plurality of objects to be transferred to a second substrate in one batch by laser lift-off, the impact on the objects to be transferred can be further reduced. Furthermore, when transferring a plurality of objects to be transferred to a second substrate in one batch by laser lift-off, the occurrence of cracks can be suppressed when using a material having a crystal structure such as a GaN layer as the ablation layer, and the generation of residues can be suppressed.

[0068] In this case, for example, the pattern of the photomask includes a first pattern and a second pattern. Through the first pattern, the laser can be collectively irradiated onto the interface between the plurality of objects to be transferred and the first substrate with the energy for peeling the object to be transferred from the first substrate, and Through the second pattern, the laser can be further configured to be collectively irradiated onto the interface between the plurality of objects to be transferred and the first substrate with the energy at which the object to be transferred does not peel off from the first substrate.

[0069] With such a laser lift-off device, multiple-stage partial irradiation can be performed without changing the laser output.

[0070] In the present invention, as a photomask of the first aspect, it is a photomask used in a laser lift-off method for transferring an object to be transferred from a first substrate provided with the object to be transferred to a second substrate by laser lift-off, configured to collectively irradiate the received laser onto the interface between each of the plurality of objects to be transferred and the first substrate. Provided is a photomask having a pattern that shapes the laser such that only a part of the interface between each of the plurality of objects to be transferred and the first substrate becomes an irradiation region.

[0071] Here, “only a part is the irradiation region” means that the laser irradiation region on each interface is a part of each interface. That is, it is sufficient that the laser irradiation region on each interface is a part of each interface, and in addition to this irradiation region, a region where no object to be transferred exists may also be included in the pattern. Therefore, a form having a pattern in which a region where no object to be transferred exists, such as between adjacent objects to be transferred as illustrated in FIGS. 4, 5, and 6 described later, is also irradiated with the laser is included in the present invention.

[0072] By using such a photomask, when a plurality of objects to be transferred are transferred to the second substrate at once by laser lift-off, partial irradiation can be performed on each of the plurality of objects to be transferred. Thereby, the impact generated during laser lift-off can be reduced, and the occurrence of breakage such as cracking and chipping of the object to be transferred during transfer can be suppressed.

[0073] For example, the pattern can be configured to shape the laser such that a plurality of the irradiation regions are formed.

[0074] Alternatively, the pattern can be configured to shape the laser such that a plurality of non-irradiation regions where the laser is not irradiated are formed on the interface between each of the plurality of objects to be transferred and the first substrate.

[0075] Thus, the pattern of the photomask according to the first aspect of the present invention may form a plurality of irradiation regions or may form a plurality of non-irradiation regions.

[0076] a first part having the pattern formed thereon and having a first laser transmittance, a second part having a second laser transmittance lower than the first laser transmittance It may have.

[0077] The photomask according to the first aspect of the present invention can also include two or more portions having different laser transmittances. By using such a photomask, it is possible to change the energy of the laser irradiated to the interface of each of the plurality of transfer objects with the first substrate without changing the laser output.

[0078] Further, in the present invention, as a photomask according to a second aspect, a photomask used in a laser lift-off method for transferring a transfer object from a first substrate provided with the transfer object to a second substrate by laser lift-off, A first portion having a pattern for shaping the received laser in a pattern shape and having a first laser transmittance, A second portion having a second laser transmittance lower than the first laser transmittance is provided.

[0079] With such a photomask according to the second aspect of the present invention, when a plurality of transfer objects are transferred to a second substrate in a batch by laser lift-off, partial irradiation can be performed on each of the plurality of transfer objects. Thereby, the impact generated at the time of laser lift-off can be reduced, and the occurrence of breakage such as cracking and chipping of the transfer object during transfer can be suppressed.

[0080] Further, by using such a photomask, it is possible to change the energy of the laser irradiated to the interface of each of the plurality of transfer objects with the first substrate without changing the laser output. Therefore, it is not necessary to provide a plurality of laser oscillators in one laser lift Off device, or to perform two laser irradiation operations by changing the laser output of the laser oscillator in one laser lift Off device, or to prepare two laser lift-off devices having different laser outputs of the laser oscillator, and laser irradiation can be performed at a multi-stage laser output by a single laser irradiation operation.

Advantages of the Invention

[0081] As described above, in the laser lift-off method of the present invention, it is possible to suppress the occurrence of damage to the object to be transferred during transfer.

[0082] Also, in the method for manufacturing a receptor substrate of the present invention, it is possible to manufacture a receptor substrate provided with an object to be transferred without damage.

[0083] Also, in the laser lift-off apparatus of the present invention, it is possible to perform a laser lift-off method capable of suppressing the occurrence of damage to the object to be transferred during transfer.

[0084] And, the photomask of the present invention can be a photomask for laser lift-off capable of suppressing the occurrence of damage to the object to be transferred during transfer.

Brief Description of the Drawings

[0085]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Mode for Carrying Out the Invention

[0086] As described above, there has been a demand for the development of a laser lift-off method capable of suppressing the occurrence of damage to an object to be transferred during transfer, a method for manufacturing a receptor substrate capable of manufacturing a receptor substrate with an undamaged object to be transferred, a laser lift-off apparatus capable of suppressing the occurrence of damage to an object to be transferred during transfer, and a photomask for laser lift-off capable of suppressing the occurrence of damage to an object to be transferred during transfer.

[0087] As a result of intensive studies on the above problems, the present inventors have adopted a batch transfer step of batch-transferring a plurality of objects to be transferred by laser lift-off in the transfer by laser lift-off, and in this batch transfer step, by irradiating a laser only to a part of the interface of each of the plurality of objects to be transferred with the first substrate, it is possible to suppress the shift of the transfer position of the object to be transferred that occurs during laser lift-off, reduce the impact that occurs during laser lift-off, and suppress the occurrence of damage such as cracks and chips in the object to be transferred during transfer, and have completed the present invention.

[0088] That is, the present invention is a laser lift-off method for transferring an object to be transferred from a first substrate having the object to be transferred to a second substrate by laser lift-off, including a batch transfer step of irradiating a laser collectively to the interfaces of the plurality of objects to be transferred and the first substrate, peeling off the plurality of objects to be transferred from the first substrate, and batch-transferring them to the second substrate, wherein, in the batch transfer step, the laser lift-off method is to irradiate the laser only to a part of the interface of each of the plurality of objects to be transferred with the first substrate.

[0089] Further, the present invention is a method for manufacturing a receptor substrate on which a plurality of objects to be transferred are arranged, including a step of preparing a donor substrate having the plurality of objects to be transferred and a receptor precursor substrate, and a step of transferring the object to be transferred from the donor substrate to the receptor precursor substrate by laser lift-off to obtain a receptor substrate and including In the step of obtaining the receptor substrate, a method for manufacturing a receptor substrate is provided, in which a plurality of transfer objects are laser-lifted off from the donor substrate as the first substrate to the receptor precursor substrate as the second substrate by the laser lift-off method of the present invention.

[0090] The present invention also relates to a laser lift-off apparatus for transferring a transfer object from a first substrate provided with the transfer object to a second substrate by laser lift-off, comprising: a laser oscillator; a stage for supporting the first substrate and the second substrate so as to face each other; a photomask disposed between the optical paths of the laser oscillator and the stage; and the laser oscillator, the photomask, and the stage are configured to irradiate the laser from the laser oscillator collectively to the interface between the plurality of transfer objects and the first substrate, wherein the photomask has a pattern that shapes the laser from the laser oscillator to irradiate only a part of the interface between each of the plurality of transfer objects and the first substrate, and is a laser lift-off apparatus.

[0091] The present invention also relates to a photomask used in a laser lift-off method for transferring a transfer object from a first substrate provided with the transfer object to a second substrate by laser lift-off, which is configured to irradiate the received laser collectively to the interface between each of the plurality of transfer objects and the first substrate, and has a pattern that shapes the laser so that only a part of the interface between each of the plurality of transfer objects and the first substrate becomes an irradiation region.

[0092] The present invention also relates to a photomask used in a laser lift-off method for transferring a transfer object from a first substrate provided with the transfer object to a second substrate by laser lift-off, A pattern is formed to shape the received laser into a pattern, and a first portion having a first laser transmittance, and a second portion having a second laser transmittance lower than the first laser transmittance is a photomask having.

[0093] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0094] [Laser Lift-Off Device] FIG. 1 schematically shows a first example of a laser lift-off device of the present invention.

[0095] The laser lift-off device 100 shown in FIG. 1 is a device configured to perform Gap-LLO.

[0096] The laser lift-off device 100 includes a laser oscillator 110, a stage 160, and a photomask 130. The laser lift-off device 100 further includes, as optional components, a shaping optical system 120, a folding mirror 140, a reduction projection lens 150, an alignment camera 170, and a controller 180.

[0097] The stage 160 includes an upper stage 161 having an opening 161a and supporting the first substrate 1, and a lower stage 162 supporting the second substrate 2. The first substrate 1 includes a plurality of transfer objects 10, similar to the first substrate 1 shown in FIGS. 21(a) and 22(a). The stage 160 is configured to support the first substrate 1 and the second substrate 2 so as to face each other.

[0098] The laser oscillator 110 is configured to oscillate a laser 20a. In the laser lift-off apparatus 100, the laser 20a oscillated from the laser oscillator 110 is shaped into a laser 20b through the shaping optical system 120, the laser 20b is shaped into a laser 20c through the photomask 130, the traveling direction of the laser 20c is changed by the folding mirror 140, and further becomes the laser 20 through the reduction projection lens 150. Each member is arranged so as to form an optical path through which this laser 20 passes through the opening 161a of the upper stage 161 and reaches the first substrate 1. That is, the photomask 130 is arranged between the optical paths of the laser oscillator 110 and the stage 160.

[0099] And in the laser lift-off apparatus 100 shown in FIG. 1, the laser oscillator 110, the photomask 130, and the stage 160 (the upper stage 161 and the lower stage 162) are configured to collectively irradiate the interface between the plurality of transfer objects 10 and the first substrate 1 with the laser 20 from the laser oscillator 110.

[0100] Hereinafter, the optical path of the laser oscillated from the laser oscillator 110 will be described.

[0101] The laser 20a oscillated from the laser oscillator 110 is, for example, an excimer laser.

[0102] An arbitrary shaping optical system 120 shapes the irradiation shape of the laser 20a oscillated from the laser oscillator 110, for example, the irradiation shape shown in FIG. 1(a), into a rectangular irradiation shape shown in FIG. 1(b), and emits it as the laser 20b. The laser 20b having a rectangular irradiation shape can exhibit a uniform irradiation energy density and is, for example, a beam profile showing a top-hat shape. However, the laser shaping by the shaping optical system 120 is not limited to this.

[0103] The photomask 130 is configured to shape the irradiation pattern of the incident laser 20b into a pattern as shown in FIG. 1(c) and emit it as the laser 20c. More specifically, the photomask 130 has a pattern that shapes the laser from the laser oscillator 110 into a shape that irradiates only a part of the interface between the first substrate 1 of each of the plurality of transfer objects 10. Also, the photomask 130 is configured to irradiate the received laser collectively onto the interface between the first substrate 1 of each of the plurality of transfer objects 10, and it can be said that it has a pattern that shapes the laser so that only a part of the interface between the first substrate 1 of each of the plurality of transfer objects 10 becomes the irradiation area.

[0104] The photomask 130 may further have a pattern that shapes it into a shape that irradiates the entire surface of the interface between the first substrate 1 of each of the plurality of transfer objects 10. Other details of the photomask 130 will be described later.

[0105] The laser 20c emitted from the photomask 130 has its traveling direction changed by the folding mirror 140 and enters the reduction projection lens 150. The reduction projection lens 150 reduces the irradiation pattern of the incident laser 20c, for example, from the one shown in FIG. 1(d) to the one shown in FIG. 1(e), and emits it as the laser 20.

[0106] By incorporating the reduction projection lens 150 into the optical path, the energy of the laser 20b incident on the photomask 130 can be made smaller than the energy required for peeling the transfer object 10 from the first substrate 1. If the reduction magnification of the reduction projection optical lens 150 is N, the energy of the laser 20b hitting the photomask 130 is 1 / (N compared to the energy of the laser 20 required for peeling the transfer object 10 from the first substrate 1. 2) This prevents deterioration of the molding optical system 120 and the photomask 130 due to laser irradiation, and can suppress thermal drift caused by the energy of the laser 20b. Therefore, thermal expansion of the photomask 130 can be suppressed, and high-precision transfer can be performed even after long-time laser lift-off. Furthermore, the influence of particles on the photomask 130 can also be reduced.

[0107] The alignment camera 170 and the controller 180 are configured to monitor the irradiation area of the laser 20 on the first substrate 1 and to control the laser oscillator 110, the photomask 130, and the stage 160 (the upper stage 161 and the lower stage 162). The controller 180 can, for example, move the photomask 130 to change the position of the pattern of the photomask 130 with respect to the optical path of the laser 20b. Also, the controller 180 can move and / or rotate the upper stage 161 on the same plane to change the position of the first substrate 1, particularly the position of the transfer object 10, with respect to the optical path of the laser 20. Further, the controller 180 can move and / or rotate the lower stage 162 on the same plane to change the position of the second substrate 2 with respect to the optical path of the laser 20.

[0108] Also, the controller 180 can control the laser lift-off apparatus 100 so as to perform the laser lift-off method of the present invention as described later.

[0109] In the laser lift-off apparatus 100 shown in FIG. 1, the laser oscillator 110, the photomask 130, the alignment camera 170, the upper stage 161, and the lower stage 162 are each electrically connected to the controller 180 via the communication line 18.

[0110] The laser lift-off apparatus 100 of the present invention is not limited to an apparatus that performs Gap-LLO as shown in FIG. 1, and may be an apparatus that performs Contact-LLO.

[0111] Figure 2 is a schematic diagram of a second example of the laser lift-off apparatus of the present invention. The laser lift-off apparatus 100 shown in Figure 2 is an apparatus configured to perform Contact-LLO. The laser lift-off apparatus 100 shown in Figure 2 is the same as the laser lift-off apparatus 100 shown in Figure 1, except that a stage 160 having an opening 160a supports the first substrate 1 and the second substrate 2 in a state where the object 10 to be transferred on the first substrate 1 is in contact with the second substrate 2.

[0112] [Laser Lift-Off Method] Hereinafter, as an example of the laser lift-off method of the present invention, an example using the laser lift-off apparatus 100 shown in Figure 1 will be described. However, the laser lift-off method of the present invention is not limited to being performed by the laser lift-off apparatus 100 shown in Figure 1, and can also be performed by the laser lift-off apparatus 100 shown in Figure 2 or other apparatuses.

[0113] The laser lift-off method of the present invention includes a batch transfer step by partial irradiation, which will be described below with reference to Figure 3.

[0114] Figure 3(a) is a schematic cross-sectional view showing the concept of laser irradiation in the batch transfer step in an example of the laser lift-off method of the present invention. Figure 3(b) is a diagram showing the positional relationship between the pattern of the photomask and one object to be transferred during the laser irradiation shown in Figure 3(a).

[0115] In this example, the laser 20a oscillated from the laser oscillator 110 shown in Figure 1 is shaped by the shaping optical system 120 to become the laser 20b. This laser 20b is incident on the photomask 130 shown in Figures 3(a) and (b).

[0116] The photomask 130 shown in Figures 3(a) and (b) includes a laser-transmissive substrate 131 and a pattern-forming layer 132 formed on the substrate 131. As shown in Figure 3(b), a pattern 31 including a plurality of openings 132a is formed in the pattern-forming layer 132.

[0117] Since the portion of the pattern formation layer 132 other than the opening 132a shields the laser, only the component of the laser 20b incident on the photomask 130 that passes through the portion corresponding to the opening 132a transmits through the photomask 130. As a result, a laser having an irradiation shape with the pattern 31 (laser 20c shown in FIG. 1) is emitted from the photomask 130. Next, although not shown in FIG. 3, the laser 20c is incident on the reduction projection lens 150 shown in FIG. 1. In the reduction projection lens 150, the laser 20c is reduced while maintaining the irradiation shape with the pattern 31 shown in FIG. 3(b) and is emitted as the laser 20.

[0118] The laser 20 emitted from the reduction projection lens 150 is incident on the surface on the side opposite to the transfer object 10 of the first substrate Plate 1. The laser 20 passes through the first substrate Plate 1 and reaches the interface 11 between the first substrate 1 and the transfer object 10.

[0119] Here, the interface does not mean a strict boundary surface, but means a region that is decomposed or the like by laser irradiation. Therefore, it can also be referred to as an ablation layer. Specifically, a form in which at least a part of the side of the first substrate 1 provided with the transfer object 10 is an ablation layer, a form in which an ablation layer is formed on the side of the first substrate 1 provided with the transfer object 10, a form in which at least a part of the side of the transfer object 10 on the first substrate 1 side is an ablation layer, a form in which an ablation layer is formed on the side of the transfer object 10 on the first substrate 1 side, and a form in which an ablation layer is located between the first substrate 1 and the transfer object 10 are included. Even if a part of the first substrate 1 or the transfer object 10 is an ablation layer, an ablation layer may be provided separately from the first substrate 1 or the transfer object 10.

[0120] Although only one object to be transferred 10 is shown in FIG. 3, in the laser lift-off method of the present invention, in the batch transfer process, for example, as shown in FIGS. 4(a) and (b), the laser 20 is irradiated all at once on the interface 11 between the plurality of objects to be transferred 10 and the first substrate 1 by the pattern 31. However, the plurality of objects to be transferred 10 do not necessarily have to be adjacent to each other as shown in the figure. For example, they may be a plurality of objects to be transferred 10 that are arranged separately without being adjacent to each other.

[0121] Now, as described above, the laser 20 has an irradiation shape having the pattern 31 of the photomask 130. Therefore, as shown in FIGS. 3(a) and (b), the laser 20 is irradiated only on a part 11a, not all, of the interface 11 between each of the plurality of objects to be transferred 10 and the first substrate 1. That is, in the laser lift-off method of the present invention, in the batch transfer process, the laser 20 is irradiated only on a part 11a of the interface 11 between each of the plurality of objects to be transferred 10 and the first substrate 1 (partial irradiation).

[0122] In the batch transfer process, by partially irradiating the plurality of objects to be transferred 10 with the laser 20 in this way, the plurality of objects to be transferred 10 are peeled off from the first substrate 1.

[0123] The energy required for peeling is energy that can weaken the bonding force (for example, adhesive force or joining force) between the object to be transferred 10 and the first substrate 1 and separate the object to be transferred 10 from the first substrate 1. For example, when there is a GaN layer at the interface between the object to be transferred 10 and the first substrate 1, in order to peel off the object to be transferred 10, it is necessary to decompose (ablate) the GaN layer. The laser energy density required at this time is high. Furthermore, nitrogen gas is generated by the decomposition of the GaN layer. The pressure of the generated nitrogen gas becomes the driving force, and the object to be transferred 10 peeled off from the first substrate 1 moves to the second substrate 2. Thereby, the transfer is achieved.

[0124] Although GaN is difficult to decompose, it decomposes rapidly when the energy threshold is exceeded. Therefore, in the batch transfer process, as shown in Fig. 22, when the entire surface of the interface 11 between each of the plurality of transfer objects 10 and the first substrate 1 is irradiated with the laser 20R at an energy capable of achieving the separation of the transfer object 10 from the first substrate 1, a large amount of nitrogen gas is rapidly generated, and the ejection vector due to the generated gas becomes too large. As a result, the transfer object 10 peeled off from the first substrate 1 is subjected to excessive pressure or the initial velocity becomes too large, and collides with the surface of the second substrate 2 with a very large ejection force from the first substrate 1 to the second substrate 2. As a result, the transfer object 10 is likely to crack during the movement from the first substrate 1 to the second substrate 2, or cracks and chips are likely to occur in the transfer object 10 when it reaches the second substrate 2. Also, due to the excessive ejection vector, it becomes difficult to control the movement of the transfer object 10 to the second substrate 2, and an unintended displacement is likely to occur when transferring the transfer object 10 to the second substrate 2.

[0125] On the other hand, in the laser lift-off method of the present invention, as described above, in the batch transfer process, by partially irradiating only a part of the interface 11 with the laser 20 to the plurality of transfer objects 10, the amount of gas generated during the separation of the plurality of transfer objects 10 from the first substrate 1 is reduced, and the pressure received by the transfer object 10 peeled off from the first substrate 1 can be reduced. As a result, the propulsive force applied to the transfer object 10 peeled off from the first substrate 1 is appropriately suppressed, and the transfer object 1 0 can reduce the impact caused by the contact with the second substrate 2. Also, the peeled transfer object 10 can be moved straight from the first substrate 1 to the second substrate 2, and a lift-off process with high transfer position accuracy can be realized.

[0126] In the above, the case where the GaN layer decomposes during peeling has been described as an example. However, since the peeling by laser lift-off is based on ablation, in the case of full-surface irradiation, the problem that the ejection vector becomes too large inevitably occurs as in the above. On the other hand, in the laser lift-off method of the present invention, by performing partial irradiation in the batch transfer process, the ejection vector can be suppressed to be small. Therefore, regardless of the combination of the first substrate 1 and the transfer object 10, the transfer object 10 can be transferred while preventing breakage such as cracking and chipping of the transfer object 10. Further, although the application of partial irradiation to laser lift-off using ablation has been described here, even in a transfer method that does not use ablation but applies a propulsive force to the transfer object by laser irradiation, the propulsive force can be relaxed by partial irradiation of the laser, leading to an improvement in transfer accuracy.

[0127] Furthermore, for example, in the transfer by the Contact-LLO method using the laser lift-off apparatus 100 shown in FIG. 2, in the case of full-surface irradiation, cracks and chips may occur due to the ejection vector becoming too large as in the above. According to the laser lift-off method of the present invention, even in the Contact-LLO method, the transfer object 10 can be transferred while preventing breakage such as cracking and chipping of the transfer object 10.

[0128] And when decomposition products are generated by laser irradiation, the generation amount of the products can be reduced, and the subsequent cleaning process can be simplified.

[0129] The laser lift-off method and the laser lift-off apparatus of the present invention can be variously modified. Hereinafter, several aspects will be described.

[0130] [Irradiation region and non-irradiation region] In the laser lift-off method of the present invention, since the laser 20 is partially irradiated only on a part of the interface 11 between each of the plurality of transfer objects 10 and the first substrate 1, an irradiation region irradiated with the laser 20 and a non-irradiation region not irradiated with the laser 20 are formed.

[0131] For example, a portion corresponding to the opening 132a of the pattern 31 of the photomask 130 shown in FIGS. 4(a) and (b) becomes the irradiation region, and a portion corresponding to the non-opening 132b other than the opening 132a of the pattern 31 becomes the non-irradiation region.

[0132] The form of partial irradiation is not particularly limited. For example, as shown in FIGS. 4(a) and (b), the laser 20 may be irradiated so that a plurality of irradiation regions are formed.

[0133] The form of the irradiation region can be appropriately changed, for example, by the pattern 31 of the photomask 130.

[0134] FIGS. 5(a) to (d) schematically show some examples of the patterns of the photomask that can be used to form a plurality of irradiation regions in the present invention.

[0135] For example, as shown in FIGS. 5(a) and (b), the opening 132a of the photomask 130 can also be circular. In FIG. 5(a), the circular openings 132a are arranged in a staggered pattern, that is, alternately. In FIG. 5(b), the circular openings 132a are arranged in a matrix pattern, that is, in a matrix. The shape of the openings 132a arranged in a staggered pattern or a matrix pattern is not limited to a circular shape, and may be an elliptical shape, a polygonal shape, or other shapes, or a combination thereof.

[0136] FIGS. 5(c) and (d) are examples where the opening 132a of the photomask 130 is rectangular. In FIG. 5(c), the longitudinal direction of the plurality of rectangular openings 132a substantially coincides with the short side direction of the transfer object 10. In FIG. 5(d), the longitudinal direction of the plurality of rectangular openings 132a substantially coincides with the longitudinal direction of the transfer object 10. Here, substantially coinciding means that two straight lines coincide or the angle formed by them is 5° or less.

[0137] Furthermore, in FIG. 5(c), a plurality of rectangular openings 132a are arranged so as to straddle adjacent transfer objects 10. By using such a photomask 130, the laser 20 can be irradiated so that the irradiation region straddles adjacent transfer objects.

[0138] Note that in the photomask 130 of the examples shown in FIGS. 4 and 5, the non-opening portions 132b other than the opening portions 132a are continuous. Therefore, according to the laser irradiation using such a photomask 130, a continuous non-irradiation region can be formed.

[0139] On the other hand, for example, if the photomask 130 of the examples shown in FIGS. 6(a) to (d) in which the pattern of the photomask 130 in each example of FIG. 5 is inverted is used, the laser 20 can be irradiated so that a plurality of non-irradiation regions are formed.

[0140] For example, as shown in FIGS. 6(a) and (b), the non-opening portions 132b of the photomask 130 can be circular. In FIG. 6(a), the circular non-opening portions 132b are arranged in a staggered pattern, that is, alternately. In FIG. 6(b), the circular non-opening portions 132b are arranged in a matrix pattern, that is, in a matrix. The shape of the non-opening portions 132b arranged in a staggered pattern or a matrix pattern is not limited to a circular shape, and may be an elliptical shape, a polygonal shape, or other shapes, or a combination thereof.

[0141] FIGS. 6(c) and (d) are examples in which the non-opening portions 132b of the photomask 130 are rectangular. In FIG. 6(c), the longitudinal direction of the plurality of rectangular non-opening portions 132b substantially coincides with the short side direction of the transfer object 10. In FIG. 6(d), the longitudinal direction of the plurality of rectangular non-opening portions 132b substantially coincides with the longitudinal direction of the transfer object 10. Here, "substantially coincides" means that two straight lines coincide or the angle formed by them is 5° or less.

[0142] In FIG. 6(c), a plurality of rectangular non-opening portions 132b are arranged so as to straddle adjacent transfer objects 10. By using such a photomask 130, the laser 20 can be irradiated so that the non-irradiation region straddles adjacent transfer objects.

[0143] Note that the means for forming a plurality of irradiation regions and the means for forming a plurality of non-irradiation regions are not limited to those exemplified above.

[0144] Further, in the batch transfer process, it is preferable to perform laser irradiation so that the area of the laser irradiation region becomes 40 to 90% of the area of the interface 11 between each first substrate 1 of the plurality of transfer objects 10.

[0145] If the area of the laser irradiation region in the batch transfer process is within the above range, it is possible to suppress the occurrence of breakage of the transfer object 10 while maintaining the transfer efficiency.

[0146] [Multi-stage irradiation] In the laser lift-off method of the present invention, it is preferable to further include a preliminary irradiation step of irradiating the interface 11 between each first substrate 1 of the plurality of transfer objects 10 with a laser having an energy smaller than the energy irradiated in the batch transfer process and with an energy at which the transfer object 10 does not peel off from the first substrate 1 before the batch transfer process described above.

[0147] By performing such a preliminary irradiation step, the impact on the transfer object 10 can be further reduced in the batch transfer process. Further, in the batch transfer process, when a material having a crystal structure such as a GaN layer is used as the ablation layer, the occurrence of cracks can be suppressed and the occurrence of residues can be suppressed.

[0148] In the preliminary irradiation step, the laser may be irradiated over the entire interface 11 between each first substrate 1 of the plurality of transfer objects 10, but it is particularly preferable to irradiate only a part of the interface 11 with the laser.

[0149] Even when performing partial irradiation in the preliminary irradiation step, when using a material having a crystal structure such as a GaN layer as the ablation layer, the generation of cracking portions can be further suppressed, and thus the generation of residues can be suppressed.

[0150] In the preliminary irradiation step, the means for irradiating the laser 20 with energy smaller than the energy irradiated in the batch transfer step and with which the transfer object 10 does not peel from the first substrate 1 is not particularly limited. Hereinafter, several examples will be given for explanation.

[0151] <First Example> FIG. 7(a) schematically shows a first example of the preliminary irradiation step in an example of the laser lift-off method of the present invention. Further, FIG. 7(b) shows an example of the batch transfer step performed after the preliminary irradiation step shown in FIG. 7(a).

[0152] In the preliminary irradiation step shown in FIG. 7(a), a part 11b of the interface 11 between each of the plurality of transfer objects 10 and the first substrate 1 is irradiated with a laser 20e with energy smaller than the energy of the laser 20 irradiated in the batch transfer step shown in FIG. 7(b) and with which the transfer object 10 does not peel from the first substrate 1.

[0153] In this example, as is clear from FIG. 7, a part 11b of the interface 11 that is irradiated with the laser 20e in the preliminary irradiation step is changed to a part 11a that is irradiated with the laser 20 in the batch transfer step. Such partial irradiation is achieved, for example, as shown in FIG. 7, by using a photomask 130 having a second pattern 32 of an opening 132c different from the pattern (first pattern) 31 of the opening 132a and performing preliminary irradiation through this second pattern 32.

[0154] FIG. 8 shows a photograph of the first substrate 1 after transferring the transfer object 10 in the preliminary irradiation step and the batch transfer step shown in FIG. 7. Further, for comparison, FIG. 9 shows a photograph of the first substrate 1 after transferring the transfer object 10 in the batch transfer step shown in FIG. 3.

[0155] As is clear from the comparison between FIGS. 8 and 9, no residue was observed on the first substrate 1 in FIG. 8 after transferring the transfer object 10 in the pre-irradiation step and the batch transfer step, while residue remained on the first substrate 1 in FIG. 9 where the pre-irradiation step was not performed. The reason will be explained below with reference to FIGS. 10 and 11.

[0156] FIG. 10 is a schematic diagram showing the mechanism of the batch transfer step shown in FIG. 3. FIG. 11 is a schematic diagram showing the mechanisms of the pre-irradiation step and the batch transfer step shown in FIG. 7.

[0157] In the batch transfer step shown in FIG. 3, as described above, the components (e.g., GaN) contained in a part 11a of the interface 11 between the transfer object 10 and the first substrate 1 are decomposed. For example, since the energy required to decompose GaN is high, the energy of the laser 20 incident on a part 11a of the interface 11 is, for example, 1.4 J / cm 2 or so. When the laser 20 having such energy irradiates a part 11a of the interface 11, these parts 11a become normal peeling parts, but energy is also transmitted to the parts adjacent to these parts 11a at the interface 11. Furthermore, the nitrogen gas generated by the decomposition of GaN generates a large ejection vector 14, and this ejection vector 14 acts on a part 11a of the interface 11, applying stress to the parts adjacent to the part 11a of the interface 11. As a result, a cleavage part 11c is generated in the part adjacent to the part 11a of the interface 11.

[0158] The generated cleavage part 11c remains on the first substrate 1 and / or on the transfer object 10 as residue 13 when the transfer object 10 is peeled off from the substrate 1. The black object shown in FIG. 9 is the residue.

[0159] On one hand, in the preliminary irradiation process shown in Fig. 11(a), a part 11b of the interface 11 between the transfer object 10 and the first substrate 1 is irradiated with a laser 20e at an energy level that prevents the transfer object 10 from peeling off the first substrate 1. In such laser irradiation, in part 11b, GaN undergoes partial separation, but the separation is extremely thin, maintaining a state where the first substrate 1 and the transfer object 10 are loosely bonded. Also, since the decomposition amount of GaN is small, the ejection vector 14 is smaller than the ejection vector shown in Fig. 10. Such preliminary irradiation can prevent the occurrence of the cleavage opening 11c shown in Fig. 10.

[0160] Then, in the example shown in Fig. 11, after the preliminary irradiation process shown in Fig. 11(a), a batch transfer process shown in Fig. 11(b) is performed. In this batch transfer process, similar to the batch transfer process shown in Fig. 10, the GaN at the interface 11 is decomposed, and the transfer object 10 is irradiated with a laser 20 at an energy level that can peel it off the first substrate 1. At this time, the same large ejection vector 14 as shown in Fig. 10 acts on a part 11a of the interface 11. However, in part 11b adjacent to part 11a of the interface 11, extremely thin separation has occurred in advance due to the preliminary irradiation process, so it is possible to prevent stress that would cause the cleavage opening 11c from acting on part 11b. As a result, as shown in Fig. 8, even after the transfer object 10 is peeled off the first substrate 1, it is possible to prevent residues as shown in Fig. 9 from remaining.

[0161] Note that in this embodiment, although the residue 13 is derived from a part of the transfer object 10, it is a part of the component for holding the transfer object 10 on the first substrate 1, so it does not significantly affect the function of the transfer object 10. Therefore, even if the residue 13 remains on the first substrate 1 or the transfer object 10, the transfer object 10 will not be damaged.

[0162] However, if the residue 13 remains after transfer, when the transfer object is a light-emitting element, there is a risk of light emission unevenness or it becoming a source of emission. Therefore, it is necessary to clean the first substrate 1 and the transfer object 10. Thus, suppressing the generation of residues is advantageous for mass production.

[0163] Here, the opening that could occur when a material having a crystal structure such as a GaN layer is used as the ablation layer has been described.

[0164] On the other hand, the present invention also effectively acts in an ablation layer where the occurrence of cleavage openings is not a problem. Specifically, when an organic film such as a polyimide film is used as the ablation layer, no cleavage openings are generated. However, by performing partial laser irradiation, the excessive propulsion force generated in the transfer object 10 during laser irradiation can be alleviated, and the transfer of the transfer object 10 onto the second substrate 2 can be controlled. Such organic films include, in addition to the polyimide film, organic films such as polymethyl methacrylate, polycarbonate, polyethylene terephthalate, nitrocellulose, polystyrene, poly(α-methylstyrene), and polytetrafluoroethylene.

[0165] When an organic film such as a polyimide film is used as the ablation layer, the energy density of the laser required for ablation of the ablation layer tends to be lower than the energy density when an inorganic film such as a GaN layer is used as the ablation layer. Specifically, the energy density required for ablation of the GaN layer is about 1200 - 1600 mJ / cm 2 whereas the energy density required for ablation of the polyimide film is about 50 - 300 mJ / cm 2 Therefore, when the shape of the laser irradiated on the photomask 6 is rectangular or linear, the length in the longitudinal direction can be increased without changing the length in the short transverse direction of the laser shape. Specifically, when trying to obtain a rectangular or linear laser with an energy density of about 1200 - 1600 mJ / cm 2 the limit of the length in the longitudinal direction is about 30 mm. However, when the energy density is 50 - 300 mJ / cm 2If the laser is in the shape of a rectangle or a line to a certain extent, the length in its longitudinal direction can be extended to about 90 mm. Therefore, when using such a laser with a long longitudinal length, laser lift-off can be performed on a large number of transfer objects 10 at once. Even if the occurrence rate of transfer defects seems low at first glance, when transferring a large number of transfer objects 10 at once, since the number of transfer objects 10 to be transferred is extremely large, a large number of transfer defects will occur. That is, when transferring a large number of transfer objects 10 at once, it is very important to improve the transfer accuracy, and the industrial effect obtained by applying the present invention will be extremely large.

[0166] Also, in the examples shown in FIGS. 7 and 11, the energy of the laser 20e that irradiates a part 11b of the interface 11 in the preliminary irradiation process is made smaller than the energy of the laser 20d that is incident on the photomask 130, that is, the output of the laser oscillator 110 shown in FIG. 1, by changing the energy of the laser 20d that is incident on the photomask 130.

[0167] <Second Example> FIG. 12(a) schematically shows a second example of the preliminary irradiation process in an example of the laser lift-off method of the present invention. FIG. 12(b) shows an example of the batch transfer process performed after the preliminary irradiation process shown in FIG. 12(a). Further, FIG. 13 shows an enlarged view of part XIII of the photomask used in FIG. 12.

[0168] The second example is different from the first example in that the energy of the laser 20b incident on the photomask 130 is not changed in the preliminary irradiation process and the batch transfer process, that is, the laser output of the laser oscillator 110 is not changed, and in terms of the second pattern 32 of the photomask 130 used in the preliminary irradiation process.

[0169] The second pattern 32 of the photomask 130 in the second example has a plurality of openings 132c, and dot-shaped non-openings 132d are provided in each opening 132c, as shown in FIGS. 12(a) and 13.

[0170] Each of the dot-shaped non-apertures 132d is smaller than the irradiation wavelength of the laser 20b irradiated onto the photomask 130. Therefore, the non-aperture 132d is not involved in the change in the irradiation shape of the laser 20b. On the other hand, when the laser 20b hits the non-aperture 132d, the energy of the laser 20b is attenuated. Therefore, the laser 20b passes through the second pattern 32 having the non-aperture 132d of the photomask 130, and while being shaped into a pattern corresponding to the aperture 132c without the non-aperture 132d, the energy is attenuated, and the laser 20f is emitted from the photomask 130. As a result, in the preliminary irradiation step of FIG. 12(a), on a part 11b of the interface 11 between each of the plurality of transfer objects 10 and the first substrate 1, the laser 20f can be irradiated with energy smaller than the energy of the laser 20 irradiated in the batch transfer step shown in FIG. 12(b), and the transfer object 10 does not peel off from the first substrate 1.

[0171] <Third Example> FIG. 14(a) schematically shows a third example of the preliminary irradiation step in an example of the laser lift-off method of the present invention. FIG. 14(b) shows an example of the batch transfer step performed after the preliminary irradiation step shown in FIG. 14(a). Further, FIG. 15 shows an enlarged view of the XV part of the photomask used in FIG. 14.

[0172] The third example is different from the second example in that stripe-shaped non-apertures 132f are provided in each aperture 132e in the second pattern 32 of the photomask 130.

[0173] The width of each of the stripe-shaped non-aperture portions 132f is smaller than the irradiation wavelength of the laser 20b irradiated onto the photomask 130. Therefore, the non-aperture portions 132f are not involved in the change in the irradiation shape of the laser 20b. On the other hand, when the laser 20b hits the non-aperture portions 132f, the energy of the laser 20b is attenuated. Therefore, the laser 20b passes through the second pattern 32 having the non-aperture portions 132f of the photomask 130, and while being shaped into a pattern corresponding to the aperture 132e as if there were no non-aperture portions 132f, the energy is attenuated, and the laser 20g is emitted from the photomask 130. As a result, in the preliminary irradiation step of FIG. 14(a), at a part 11b of the interface 11 with the first substrate 1 of each of the plurality of transfer objects 10, the energy is smaller than the energy of the laser 20 irradiated in the batch transfer step shown in FIG. 14(b), and the laser 20g can be irradiated with an energy that does not cause the transfer object 10 to peel off from the first substrate 1.

[0174] <Fourth Example> FIG. 16(a) schematically shows a fourth example of the preliminary irradiation step in an example of the laser lift-off method of the present invention. Further, FIG. 16(b) shows an example of the batch transfer step performed after the preliminary irradiation step shown in FIG. 16(a). Further, FIG. 17 shows an enlarged view of part XVII of the photomask used in FIG. 16.

[0175] The fourth example is different from the second example in that the second pattern 32 of the photomask 130 includes a plurality of phase shift mask portions 132g.

[0176] A part of the components of the laser 20b incident on the phase shift mask portion 132g is phase-shifted by 180° by passing through a phase shift film included in the phase shift mask portion 132g. Since the components with the phase shift are 180° out of phase with the components that did not pass through the phase shift film, they cancel each other out. As a result, the phase shift mask portion 132 gThe energy of the laser 20b incident thereon is attenuated. Therefore, the laser 20b passes through the second pattern 32 having the phase shift mask portion 132g of the photomask 130, and while being shaped into a pattern corresponding to the phase shift mask portion 132g, the energy is attenuated, and the laser 20h is emitted from the photomask 130. Thereby, in the preliminary irradiation step of FIG. 16(a), at a part 11b of the interface 11 with the first substrate 1 of each of the plurality of transfer objects 10, the energy is smaller than the energy of the laser 20 irradiated in the batch transfer step shown in FIG. 16(b), and the laser 20h can be irradiated with an energy at which the transfer object 10 does not peel off from the first substrate 1.

[0177] Thus, for example, according to the second to fourth examples, in the preliminary irradiation step, without changing the output of the laser from the laser oscillator 110, at a part 11b of the interface 11 with the first substrate 1 of each of the plurality of transfer objects 10, the energy is smaller than the energy of the laser 20 irradiated in the batch transfer step performed in the subsequent stage, and the laser can be irradiated with an energy at which the transfer object 10 does not peel off from the first substrate 1. The fact that the preliminary irradiation step and the batch transfer step can be performed without changing the output of the laser oscillator 110 is very advantageous in terms of mass production.

[0178] A specific example in which the preliminary irradiation step and the batch transfer step of the second example described with reference to FIGS. 12 and 13 can be performed will be described with reference to FIGS. 18 and 19.

[0179] FIG. 18 is a schematic diagram showing an example of the arrangement of the photomask 130 capable of performing the preliminary irradiation step and the batch transfer step of the second example and the plurality of transfer objects 10. In FIG. 18, illustrations other than the photomask 130 and the plurality of transfer objects 10 are omitted.

[0180] The photomask 130 shown in FIG. 18 includes a second portion 134 having the second pattern 32 shown in FIG. 12(a) and a first portion 133 having the first pattern 31 shown in FIG. 12(b).

[0181] The arrows in FIG. 18 indicate the moving directions of a plurality of transfer objects 10. In this example, the photomask 130 and the transfer objects 10 are arranged such that the second pattern 32 of the photomask 130 comes onto the plurality of transfer objects 10 before the first pattern 31.

[0182] In the second pattern 32, a chromium shielding film which is a pattern formation layer 132 having openings 132c and dot-shaped non-openings 132d shown in FIGS. 12(a) and 13 formed thereon is formed on a quartz glass which is a base material 131.

[0183] The dot-shaped non-openings 132d shield 15% of the opening area of each opening 132c.

[0184] On the other hand, in the first pattern 31, a chromium shielding film which is a pattern formation layer 132 having an opening 132a shown in FIG. 12(b) formed thereon is formed on a quartz glass which is a base material 131.

[0185] Therefore, the first portion 133 of the photomask 130 has a first laser transmittance, and the second portion 134 has a second laser transmittance lower than the first laser transmittance.

[0186] Specifically, when laser lift-off is performed in such an arrangement, the energy (energy density) of the laser 20f irradiated to a part 11b of the interface 11 between each of the plurality of transfer objects 10 and the first substrate 1 in the preliminary irradiation step shown in FIG. 12(a) is 15% lower than the energy of the laser 20 irradiated to a part 11a of the interface 11 between each of the plurality of transfer objects 10 and the first substrate 1 in the batch transfer step shown in FIG. 12(b). For example, if the energy irradiated to a part 11a of the interface 11 in the batch transfer step is 1.4 J / cm 2 then the energy of the laser 20f irradiated to a part 11b of the interface 11 in the preliminary irradiation step is 1.2 J / cm 2 and becomes so.

[0187] When the preliminary irradiation process and the batch transfer process are performed in the arrangement shown in FIG. 18, for example, as shown in FIG. 19, the second pattern 32 of the plurality of irradiation regions 32a in the preliminary irradiation process and the first pattern 31 of the plurality of irradiation regions 31a in the batch transfer process are formed so as to be displaced.

[0188] In FIG. 18, as an example, a photomask 130 having the second pattern 32 shown in FIGS. 12 and 13 is shown. However, the photomask 130 used in the present invention may have the second pattern 32 of other examples described above, or may have other second patterns.

[0189] The preliminary irradiation process described above can be performed in various modes.

[0190] For example, the preliminary irradiation process can be performed, for example, 1 to 4 times.

[0191] The number of times of the preliminary irradiation process is not particularly limited. However, by performing the preliminary irradiation process once or twice, the speed of the transfer operation by laser lift-off can be improved. Further, by performing the preliminary irradiation process three or four times, it becomes easier to control the impact applied to the transfer object at the time of laser lift-off while appropriately maintaining the speed of the transfer operation by laser lift-off.

[0192] For example, in each of the preliminary irradiation process and the batch transfer process, it is preferable to perform laser irradiation so that the irradiation region of the laser (for example, the irradiation regions 31a and 32a shown in FIG. 19) becomes 10 to 60% of the area of the interface 11 between each first substrate 1 of the plurality of transfer objects 10.

[0193] If the irradiation region in the partial irradiation in each of the preliminary irradiation process and the batch transfer process is within the range of 10 to 60% of the area of the interface 11 between each first substrate 1 of the plurality of transfer objects 10, the transfer object can be efficiently transferred from the first substrate to the second substrate, and a margin can be provided for the laser irradiation error.

[0194] Further, it is preferable to change the irradiation region of the laser between the preliminary irradiation process and the batch transfer process.

[0195] By changing the laser irradiation area between the preliminary irradiation step and the batch transfer step, for example, as described with reference to FIG. 11, when a material having a crystal structure such as a GaN layer is used as the ablation layer, the generation of the cleavage portion 13 as shown in FIG. 10 can be suppressed.

[0196] Further, it is preferable that the preliminary irradiation step and the batch transfer step are performed such that there is no overlapping portion of the laser irradiation areas, or the overlapping portion of the laser irradiation areas is 10% or less of the area of the interface 11 between the first substrate 1 of each of the plurality of transfer objects 10.

[0197] The irradiation areas in the preliminary irradiation step and the batch transfer step may overlap, and by setting the overlapping portion to be more than 0% and 10% or less, a margin can be provided for the laser irradiation error.

[0198] For example, by arranging the openings of the first portion 133 and the second portion 134 of the photomask 130 in a matrix, the overlapping state of the irradiation areas can be easily controlled.

[0199] Further, when the irradiation area or the non-irradiation area is linear as shown in FIGS. 4, 5(c) and (d), and FIGS. 6(c) and (d), it is preferable to arrange the irradiation area or the non-irradiation area at an interval of not less than the width in the short side direction. By doing so, the overlapping state of the irradiation areas can be easily controlled.

[0200] Also, the laser can be irradiated to 40 to 100% of the area of the interface 11 between the first substrate 1 of each of the plurality of transfer objects 10 in total in the preliminary irradiation step and the batch transfer step.

[0201] By irradiating a laser on an area of 40% or more of the interface 11 between each of the plurality of transfer objects 10 and the first substrate 1 in total of the preliminary irradiation process and the batch transfer process, transfer can be performed more efficiently. Also, in total of the preliminary irradiation process and the batch transfer process, the laser may be irradiated on the entire area, that is, 100% of the interface 11 between each of the plurality of transfer objects 10 and the first substrate 1.

[0202] And it is particularly preferable that the laser lift-off device of the present invention is configured to enable the preliminary irradiation process described above.

[0203] For example, as in the first example described with reference to FIG. 7, the laser lift-off device 100 of the present invention is further configured such that the energy of the laser irradiated on the interface 11 between the plurality of transfer objects 10 and the first substrate 1 can be switched between the energy at which the transfer object 10 does not peel off from the first substrate 1 and the energy at which the transfer object 10 peels off from the first substrate 1.

[0204] Alternatively, as in the second to fourth examples described with reference to FIGS. 12 to 17, the laser lift-off device 100 of the present invention has a pattern of the photomask 130 including a first pattern 31 and a second pattern 32. Through the first pattern 31, the laser 20 can be batch-irradiated on the interface 11 between the plurality of transfer objects 10 and the first substrate 1 with the energy for peeling the transfer object 10 from the first substrate 1, and through the second pattern 32, the laser can be batch-irradiated on the interface 11 between the plurality of transfer objects 10 and the first substrate 1 with the energy at which the transfer object 10 does not peel off from the first substrate 1. The laser lift-off device 100 in this aspect is advantageous in terms of mass production.

[0205] [Transfer object] The object to be transferred in the present invention is not particularly limited. For example, as the object to be transferred, those selected from the group consisting of semiconductor chips, LED chips, resin material films, and inorganic films can be transferred. In the resin material film, an inorganic material may be contained in the film. Further, the resin material film may have a multilayer structure, and the plurality of films constituting the multilayer structure may consist only of resin material films, or may be a combination of resin material films and inorganic material films.

[0206] When a transfer object as thin as 1 to 10 μm in thickness is irradiated over the entire surface by a normal laser lift-off method, when the dimension in the longitudinal direction of the transfer object or the area of the transfer object increases, the transfer object is likely to be damaged during laser lift-off. Specifically, in the case of a transfer object with a longitudinal dimension of 80 μm or more or an area of 6400 μm 2 or more, since the transfer object is likely to crack during laser lift-off by full-surface irradiation, the application of the present invention capable of relaxing the propulsive force applied to the transfer object is effective. There is no particular limitation on the upper limits of the longitudinal dimension and the area, but from the viewpoint of ease of production, they are each 500 μm or less and 40000 μm 2 or less.

[0207] [Method for manufacturing a receptor substrate] The laser lift-off method of the present invention described above can be applied, for example, to a method for manufacturing a receptor substrate.

[0208] For example, a method for manufacturing a receptor substrate on which a plurality of transfer objects are arranged, the method including: a step of preparing a donor substrate having the plurality of transfer objects and a receptor precursor substrate; and a step of transferring the transfer objects from the donor substrate to the receptor precursor substrate by laser lift-off to obtain a receptor substrate. In the step of obtaining the receptor substrate, in accordance with the laser lift-off method of the present invention, laser lift-off is performed on the plurality of transfer objects from the donor substrate as the first substrate to the receptor precursor substrate as the second substrate. If it is a method for manufacturing a receptor substrate, since the transfer objects are transferred by the laser lift-off method of the present invention to obtain a receptor substrate, a receptor substrate having transfer objects without displacement or damage can be manufactured.

[0209] The method for manufacturing a receptor substrate of the present invention is an example of the application of the laser lift-off method of the present invention, and the application of the laser lift-off method of the present invention is not limited thereto.

[0210] [Photomask] The photomask of the present invention is a photomask that can be used in the laser lift-off method of the present invention described above. Therefore, the photomask of the present invention includes all aspects of the photomask 130 described above.

[0211] For example, the photomask of the first aspect of the present invention is a photomask 130 used in a laser lift-off method for transferring a transfer object 10 from a first substrate 1 having the transfer object 10 to a second substrate 2 by laser lift-off. The photomask is configured to irradiate the received laser collectively at the interface 11 between each of the plurality of transfer objects 10 and the first substrate 1, and has a pattern 31 for shaping the laser so that only a part 11a of the interface between each of the plurality of transfer objects 10 and the first substrate 1 becomes the irradiation region. 11 It is a photomask having a pattern 31 for shaping the laser so that only a part 11a of the interface between each of the plurality of transfer objects 10 and the first substrate 1 becomes the irradiation region.

[0212] As described above, the pattern 31 of the photomask 130 may be configured to shape the laser so that a plurality of irradiation regions are formed, or may be configured to shape the laser so that a plurality of non-irradiation regions where the laser is not irradiated are formed with respect to the interface 11 between each of the plurality of transfer objects 10 and the first substrate 1.

[0213] Also, for example, if a photomask 130 having a first portion 133 where a pattern (first pattern) 31 is formed and having a first laser transmittance and a second portion 134 having a second laser transmittance lower than the first laser transmittance is used, the preliminary irradiation step and the batch transfer step described above can be performed without changing the output of the laser oscillator 110.

[0214] Viewing such a photomask 130 from another aspect, the photomask according to the second aspect of the present invention is a photomask used in a laser lift-off method for transferring a transfer object 10 from a first substrate 1 provided with the transfer object 10 to a second substrate 2 by laser lift-off, and has a pattern 31 for shaping the received laser into a pattern shape and a first portion 133 having a first laser transmittance and a second portion 134 having a second laser transmittance lower than the first laser transmittance, which can be referred to as the photomask 130.

[0215] By performing the laser lift-off method of the present invention using the photomask 130 of the present invention, it is possible to suppress the occurrence of displacement of the transfer object and breakage of the transfer object during transfer. Note that the laser lift-off method of the present invention can be performed without using the photomask 130 of the present invention.

Examples

[0216] Hereinafter, the present invention will be specifically described using examples and comparative examples, but the present invention is not limited thereto.

[0217] (Example 1) A sapphire substrate having 1.5 million LED chips as transfer objects was prepared as the first substrate. The size of the LED chips was 40 μm × 60 μm.

[0218] Also, a quartz substrate having a silicone rubber layer as an adhesive layer on its surface was prepared as the second substrate.

[0219] In Example 1, a total of 1.5 million LED chips were transferred from the first substrate to the second substrate by the Contact-LLO method using the laser lift-off apparatus shown in FIG. 2.

[0220] In Example 1, a pre-irradiation step and a batch transfer step were performed using the photomask 130 described with reference to FIGS. 12, 13, and 18. Specifically, in this example, as shown in FIG. 18, since a plurality of transfer objects are relatively moved in the direction of the arrow with respect to the photomask, the laser lift-off is actually performed in the following order. (i) Pre-irradiation step for the lower row (ii) Batch transfer step for the lower row and pre-irradiation step for the upper row (iii) Batch transfer step for the upper row and pre-irradiation step for the row one above the upper row (iv) Batch transfer step for the row one above the upper row and pre-irradiation step for the row two above the upper row Of course, the pre-irradiation step and the batch transfer step may be completed for each fixed area, for example, for each row, and then the pre-irradiation step and the batch transfer step for other areas may be performed. Also, after performing the pre-irradiation step for all the LED chips, the batch transfer step may be performed for all the LED chips. Here, the pre-irradiation step for all the LED chips may be a single pre-irradiation step or a plurality of pre-irradiation steps divided for each fixed area. Also, the batch transfer step for all the LED chips may be a single batch transfer step or a plurality of batch transfer steps divided for each fixed area.

[0221] The first pattern 31 and the second pattern 32 of the photomask 130 were each a 1:1 line & space pattern with a size of 8 μm.

[0222] In the preliminary irradiation process, the energy (energy density) of the laser 20f irradiated to a part 11b of the interface 11 between each of the transfer objects 10 and the first substrate 1 was set to 1.2 J / cm 2 .

[0223] Thereafter, the photomask 130 was moved 8 μm in the direction of the arrow shown in Fig. 18, and a batch transfer process was performed.

[0224] In the batch transfer process, the energy (energy density) of the laser 20 irradiated to a part 11a of the interface 11 between each of the plurality of transfer objects 10 and the first substrate 1 was set to 1.4 J / cm 2 .

[0225] (Example 2) In Example 2, a total of 1.5 million LED chips were transferred from the first substrate to the second substrate in the same manner as in Example 1, except that the preliminary irradiation process was not performed.

[0226] (Comparative Example) In the comparative example, a total of 1.5 million LED chips were transferred from the first substrate to the second substrate in the same manner as in Example 2, except that in the batch transfer process, the entire interface 11 between each of the plurality of transfer objects 10 and the first substrate 1 was irradiated with a laser.

[0227] When the LED chips transferred to the second substrate in Examples 1 and 2 were checked, the positional accuracy of the LED chips was high, and no major damage to the LED chips was confirmed.

[0228] On the other hand, among the LED chips transferred to the second substrate in the comparative example, damage to 10% of the LED chips was confirmed.

[0229] Also, a photograph of the first substrate after transfer in Example 1 is shown in FIG. 20. As is clear from FIG. 20, almost no residue was observed on the first substrate after transfer in Example 1.

[0230] On the other hand, a photograph of the first substrate after transfer in Example 2 is shown in FIG. 9. As is clear from FIG. 9, some residues were observed on the first substrate after transfer in Example 2.

[0231] In this evaluation, due to the relationship of the light used in the microscope, the residue was observed as a black residue.

[0232] In the above-described embodiment, an example of lifting off an LED chip having a GaN layer, which is an object to be transferred, from a sapphire substrate serving as the first substrate has been described, but the present embodiment is not limited thereto. Specifically, it is also applicable when transferring a resin material film or an inorganic film such as a chip shape, a microdevice, or a chip provided on a first substrate made of a sapphire substrate or a glass substrate to a second substrate. Furthermore, it also includes the case of transferring an object to be transferred adhered via an ablation layer from a first substrate having an ablation layer such as a polyimide film formed on the surface to a second substrate.

[0233] Also, the present invention is not limited to the above-described embodiment. The above-described embodiment is an example, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same operational effects is included in the technical scope of the present invention. The invention described in the claims at the time of filing is appended below. [1] A laser lift-off method for transferring a transfer object from a first substrate having the transfer object to a second substrate by laser lift-off, comprising: a batch transfer step of collectively irradiating a laser on the interfaces between a plurality of the transfer objects and the first substrate to peel the plurality of transfer objects from the first substrate and collectively transfer them to the second substrate; The laser lift-off method according to [1], wherein in the batch transfer step, the laser is irradiated only on a part of the interface between each of the plurality of transfer objects and the first substrate. [2] The laser lift-off method according to [1], further comprising a preliminary irradiation step of irradiating a laser on the interface between each of the plurality of transfer objects and the first substrate with energy smaller than the energy irradiated in the batch transfer step and with energy at which the transfer object does not peel from the first substrate, before the batch transfer step. [3] The laser lift-off method according to [2], wherein in the preliminary irradiation step, the laser is irradiated only on a part of the interface between each of the plurality of transfer objects and the first substrate. [4] The laser lift-off method according to [2] or [3], wherein the preliminary irradiation step is performed 1 to 4 times. [5] The laser lift-off method according to any one of [2] to [4], wherein in each of the preliminary irradiation step and the batch transfer step, laser irradiation is performed such that the irradiation area of the laser is 10% to 60% of the area of the interface between each of the plurality of transfer objects and the first substrate. [6] The laser lift-off method according to any one of [2] to [5], wherein the irradiation area of the laser is changed between the preliminary irradiation step and the batch transfer step. [7] The laser lift-off method according to [6], wherein the preliminary irradiation step and the batch transfer step are performed such that there is no overlapping portion of the irradiation area of the laser, or the overlapping portion of the irradiation area of the laser is 10% or less of the area of the interface between each of the plurality of transfer objects and the first substrate. [8]The laser lift-off method according to [6] or [7], wherein, in total of the pre-irradiation step and the batch transfer step, the laser is irradiated to 40 to 100% of the area of the interface between each of the plurality of transfer objects and the first substrate. [9]The laser lift-off method according to any one of [2] to [8], wherein the output of the laser is changed between the pre-irradiation step and the batch transfer step.

[10] Prepare a photomask including a first portion having a first laser transmittance and a second portion having a second laser transmittance lower than the first laser transmittance.

[11] In the pre-irradiation step, the laser is irradiated through the second portion of the photomask.

[12] The laser lift-off method according to any one of [2] to [8], wherein, in the batch transfer step, the laser is irradiated through the first portion of the photomask.

[11] The laser lift-off method according to [1], wherein, in the batch transfer step, laser irradiation is performed such that the laser irradiation area is 40 to 90% of the area of the interface between each of the plurality of transfer objects and the first substrate.

[12] The laser lift-off method according to any one of [1] to

[11] , wherein, in the batch transfer step, the laser is irradiated such that a plurality of irradiation areas where the laser is irradiated are formed on the interface between each of the plurality of transfer objects and the first substrate.

[13] The laser lift-off method according to

[12] , wherein, in the batch transfer step, the laser is irradiated such that the irradiation area has at least one shape selected from the group consisting of a circular shape, an elliptical shape, and a polygonal shape.

[14] The laser lift-off method according to

[12] , wherein, in the batch transfer step, the laser is irradiated such that the irradiation area has a linear shape.

[15] The laser lift-off method according to

[12] , wherein, in the batch transfer step, the irradiation area has a rectangular shape or a linear shape, and the laser is irradiated such that the longitudinal direction of the irradiation area substantially coincides with the longitudinal direction of the transfer object.

[16] The laser lift-off method according to

[12] , wherein, in the batch transfer step, the irradiation area has a rectangular shape or a linear shape, and the laser is irradiated such that the longitudinal direction of the irradiation area substantially coincides with the short-side direction of the transfer object.

[17] The laser lift-off method according to

[12] , wherein in the batch transfer process, the irradiation region has a rectangular or linear shape, and the laser is irradiated so as to straddle the transfer target adjacent to the irradiation region.

[18] The laser lift-off method according to any one of [1] to

[11] , wherein in the batch transfer process, the laser is irradiated so that a plurality of non-irradiation regions where the laser is not irradiated are formed at the interface between each of the plurality of transfer targets and the first substrate.

[19] The laser lift-off method according to

[18] , wherein in the batch transfer process, the laser is irradiated so that the non-irradiation region has at least one shape selected from the group consisting of a circular shape, an elliptical shape, and a polygonal shape.

[20] The laser lift-off method according to

[18] , wherein in the batch transfer process, the laser is irradiated so that the non-irradiation region has a linear shape.

[21] The laser lift-off method according to

[18] , wherein in the batch transfer process, the non-irradiation region has a rectangular or linear shape, and the laser is irradiated so that the longitudinal direction of the non-irradiation region substantially coincides with the longitudinal direction of the transfer target.

[22] The laser lift-off method according to

[18] , wherein in the batch transfer process, the non-irradiation region has a rectangular or linear shape, and the laser is irradiated so that the longitudinal direction of the non-irradiation region substantially coincides with the short-side direction of the transfer target.

[23] The laser lift-off method according to

[18] , wherein in the batch transfer process, the non-irradiation region has a rectangular or linear shape, and the laser is irradiated so as to straddle the transfer target adjacent to the non-irradiation region.

[24] The laser lift-off method according to any one of [1] to

[23] , wherein the transfer target is a semiconductor chip, an LED chip, a resin material film, or an inorganic film selected from the group.

[25] A method for manufacturing a receptor substrate on which a plurality of transfer targets are arranged, comprising a step of preparing a donor substrate having the plurality of transfer targets and a receptor precursor substrate, and a step of transferring the transfer target from the donor substrate to the receptor precursor substrate by laser lift-off to obtain a receptor substrate and including. In the step of obtaining the receptor substrate, a method for manufacturing a receptor substrate in which a plurality of transfer objects are laser lifted off from the donor substrate as the first substrate to the receptor precursor substrate as the second substrate by the laser lift-off method according to any one of [1] to

[23] .

[26] A laser lift-off apparatus for transferring a transfer object from a first substrate having the transfer object to a second substrate by laser lift-off, a laser oscillator, a stage for supporting the first substrate and the second substrate so as to face each other, and a photomask disposed between the optical paths of the laser oscillator and the stage and comprising, the laser oscillator, the photomask, and the stage are configured to irradiate the laser from the laser oscillator onto the interface between the plurality of transfer objects and the first substrate all at once, the photomask has a pattern that shapes the laser from the laser oscillator to irradiate only a part of the interface between each of the plurality of transfer objects and the first substrate, and is a laser lift-off apparatus.

[27] The laser lift-off apparatus according to

[26] , further configured such that the energy of the laser irradiated onto the interface between the plurality of transfer objects and the first substrate can be switched between energy at which the transfer object does not peel off from the first substrate and energy at which the transfer object peels off from the first substrate.

[28] The pattern of the photomask includes a first pattern and a second pattern, through the first pattern, the laser can be irradiated onto the interface between the plurality of transfer objects and the first substrate all at once with the energy for peeling the transfer object from the first substrate, and through the second pattern, the laser can be further configured to be irradiated onto the interface between the plurality of transfer objects and the first substrate all at once with the energy at which the transfer object does not peel off from the first substrate. The laser lift-off apparatus according to claim 27.

[29] A photomask used in a laser lift-off method for transferring a transfer object from a first substrate having the transfer object to a second substrate by laser lift-off, configured to irradiate the received laser onto the interface between each of the plurality of transfer objects and the first substrate all at once, A photomask having a pattern that shapes the laser so that only a part of the interface between each of the plurality of objects to be transferred and the first substrate becomes an irradiation region.

[30] The photomask according to

[29] , wherein the pattern shapes the laser so that a plurality of the irradiation regions are formed.

[31] The photomask according to

[29] , wherein the pattern shapes the laser so that a plurality of non-irradiation regions where the laser is not irradiated are formed with respect to the interface between each of the plurality of objects to be transferred and the first substrate.

[32] A first part having the pattern formed thereon and having a first laser transmittance, A second part having a second laser transmittance lower than the first laser transmittance The photomask according to any one of

[29] to

[31] .

[33] A photomask used in a laser lift-off method for transferring an object to be transferred from a first substrate provided with the object to be transferred to a second substrate by laser lift-off, A first part having a pattern formed thereon that shapes the received laser in a pattern shape and having a first laser transmittance, A second part having a second laser transmittance lower than the first laser transmittance The photomask having.

Claims

1. A laser lift-off device for transferring an object to be transferred from a first substrate having the object to be transferred to a second substrate by laser lift-off, comprising: a laser oscillator; a stage for supporting the first substrate and the second substrate so as to face each other; a photomask disposed between the optical paths of the laser oscillator and the stage; The laser oscillator, the photomask, and the stage are configured to irradiate the interface between the plurality of objects to be transferred and the first substrate with the laser from the laser oscillator all at once. The photomask has a pattern that shapes the laser from the laser oscillator to irradiate only a part of the interface between each of the plurality of objects to be transferred and the first substrate. The laser lift-off device is as described above.

2. The laser lift-off device according to claim 1, further configured such that the energy of the laser irradiated on the interface between the plurality of objects to be transferred and the first substrate can be switched between energy at which the object to be transferred does not peel off from the first substrate and energy at which the object to be transferred peels off from the first substrate.

3. The pattern of the photomask includes a first pattern and a second pattern. Through the first pattern, the laser can be irradiated all at once on the interface between the plurality of objects to be transferred and the first substrate with energy at which the object to be transferred peels off from the first substrate, and through the second pattern, the laser can be irradiated all at once on the interface between the plurality of objects to be transferred and the first substrate with energy at which the object to be transferred does not peel off from the first substrate. The laser lift-off device according to claim 1 is further configured as described above.

4. A photomask used in a laser lift-off method for transferring an object to be transferred from a first substrate having the object to be transferred to a second substrate by laser lift-off, configured to irradiate the interface between each of the plurality of objects to be transferred and the first substrate with the received laser all at once, and having a pattern that shapes the laser such that only a part of the interface between each of the plurality of objects to be transferred and the first substrate becomes an irradiation region.

5. The photomask according to claim 4, wherein the pattern shapes the laser such that a plurality of the irradiation regions are formed.

6. ​ ​ ​ ​ ​ The photomask according to claim 4, wherein the laser is shaped such that a plurality of non-irradiation regions where the laser is not irradiated are formed on the interface between the first substrate and each of the plurality of objects to be transferred.

7. A first portion in which the pattern is formed and which has a first laser transmittance, and a second portion having a second laser transmittance lower than the first laser transmittance The photomask according to any one of claims 4 to 6, comprising:

8. A photomask used in a laser lift-off method for transferring an object to be transferred from a first substrate provided with the object to be transferred to a second substrate by laser lift-off, A first portion in which a pattern for shaping the received laser into a pattern is formed and which has a first laser transmittance, and a second portion having a second laser transmittance lower than the first laser transmittance The photomask according to claim 9, comprising:

9. A transfer device for transferring an object to be transferred from a first substrate provided with the object to be transferred to a second substrate by laser, A laser oscillator, A stage for supporting the first substrate and the second substrate so as to face each other, And a photomask disposed between the optical paths of the laser oscillator and the stage Comprising: The laser oscillator, the photomask, and the stage are configured to collectively irradiate the interface between the plurality of objects to be transferred and the first substrate with the laser from the laser oscillator, The transfer device, wherein the photomask has a pattern for shaping the laser from the laser oscillator into a shape that irradiates only a part of the interface between each of the plurality of objects to be transferred and the first substrate.

10. The transfer device according to claim 9, further configured such that the energy of the laser irradiated on the interface between the plurality of objects to be transferred and the first substrate can be switched between energy at which the object to be transferred does not peel off from the first substrate and energy at which the object to be transferred peels off from the first substrate.

11. The pattern of the photomask includes a first pattern and a second pattern, Through the first pattern, the laser can be collectively irradiated on the interface between the plurality of objects to be transferred and the first substrate with energy for peeling the object to be transferred from the first substrate, and The transfer device according to claim 9, further configured such that the laser can be collectively irradiated onto the interface between the plurality of objects to be transferred and the first substrate through the second pattern with energy that does not cause the object to be transferred to peel off from the first substrate.

12. A photomask used in a transfer method for transferring an object to be transferred from a first substrate having the object to be transferred to a second substrate by a laser, configured to collectively irradiate the received laser onto the interface between each of the plurality of objects to be transferred and the first substrate, the photomask having a pattern that shapes the laser such that only a part of the interface between each of the plurality of objects to be transferred and the first substrate becomes an irradiation region.

13. The photomask according to claim 12, wherein the pattern shapes the laser such that a plurality of the irradiation regions are formed.

14. The photomask according to claim 12, wherein the pattern shapes the laser such that a plurality of non-irradiation regions where the laser is not irradiated are formed on the interface between each of the plurality of objects to be transferred and the first substrate.

15. A first portion having the pattern formed thereon and having a first laser transmittance, and a second portion having a second laser transmittance lower than the first laser transmittance The photomask according to any one of claims 12 to 14.

16. A photomask used in a transfer method for transferring an object to be transferred from a first substrate having the object to be transferred to a second substrate by a laser, a first portion having a pattern formed thereon that shapes the received laser in a pattern and having a first laser transmittance, and a second portion having a second laser transmittance lower than the first laser transmittance The photomask having.

Images