Abstract: A method of processing a wafer includes a composite substrate forming step of joining a face side of a wafer and a surface of a support substrate to each other with a joint member interposed therebetween, a grinding step of grinding a reverse side of the wafer of the composite substrate to thin down the wafer to a finished thickness, a transfer member affixing step of affixing a transfer member to the reverse side of the wafer, a joint member breaking step of breaking the joint member by applying a laser beam having a wavelength transmittable through the support substrate and absorbable by the joint member to the composite substrate from another surface side of the support substrate, and a transferring step of peeling off the support substrate from the wafer and transferring the wafer to the transfer member.

Abstract: A lift-off method includes joining a transfer substrate to a face side of an optical device layer of an optical device wafer with a joining member interposed therebetween, thereby making up a composite substrate, applying a pulsed laser beam having a wavelength transmittable through the epitaxy substrate and absorbable by a buffer layer, from a reverse side of the epitaxy substrate of the optical device wafer, thereby breaking the buffer layer, and an optical device layer transferring step of peeling off the epitaxy substrate from the optical device layer and transferring the optical device layer to the transfer substrate. The optical device layer transferring step includes the step of applying a bending moment to an area of the composite substrate that includes an outer peripheral portion thereof while holding an area of the composite substrate that includes a central portion thereof.

Abstract: A laser beam irradiation unit of a laser processing apparatus includes a laser oscillator that emits a laser beam, a characteristic conversion optical element that converts a characteristic of the laser beam emitted from the laser oscillator, a mirror and a collecting lens that are optical elements that guide the laser beam to a workpiece, a detecting unit that detects the water retention state of the characteristic conversion optical element, and a drying unit that dries the characteristic conversion optical element.

Abstract: A lift-off method includes a dividing step of dividing a buffer layer and an optical device layer stacked on a front side of a substrate to thereby form separate buffer layers and separate optical device layers, a transfer member bonding step of bonding a transfer member to a front side of the separate optical device layers, a buffer layer breaking step of applying a pulsed laser beam to the separate buffer layers to thereby break the separate buffer layers, and an optical device layer transferring step of transferring the separate optical device layers from the substrate to the transfer member. An energy density of each pulse of the pulsed laser beam is set to 1.0 to 5.0 mJ/mm2.

Abstract: A lift-off method includes a relocation substrate joining step of joining a relocation substrate to a surface of an optical device layer of an optical device wafer with a joining member interposed therebetween, thereby forming a composite substrate, a buffer layer breaking step of applying a pulsed laser beam having a wavelength transmittable through an epitaxy substrate and absorbable by a buffer layer to the buffer layer from a reverse side of the epitaxy substrate of the optical device wafer of the composite substrate, thereby breaking the buffer layer, and an optical device layer relocating step of peeling off the epitaxy substrate from the optical device layer, thereby relocating the optical device layer to the relocation substrate. In the buffer layer breaking step, irradiating conditions of the pulsed la-ser beam are changed for respective ring-shaped areas of the buffer layer, and the pulsed laser beam is applied to the optical device wafer under the changed irradiating conditions.

Abstract: A comparing method includes a processing trace forming step of positioning a condenser at a reference height and a plurality of heights by moving the condenser, and forming a plurality of processing traces in one surface of a workpiece by irradiating different positions of the one surface with a laser beam according to each of the heights, a calculating step of calculating at least one of an average of widths in a plurality of predetermined directions of each of the plurality of processing traces and an area ratio of each of the plurality of processing traces to a circle of a predetermined diameter by analyzing an image of the plurality of processing traces by an image analyzing section, and a comparing step of quantitatively comparing deviations of the plurality of processing traces from a predetermined shape on the basis of at least one of the average and the area ratio.

Abstract: A lift-off method includes a relocation substrate joining step of joining a relocation substrate to a surface of an optical device layer of an optical device wafer with a joining member interposed therebetween, thereby forming a composite substrate, a buffer layer breaking step of applying a pulsed laser beam having a wavelength transmittable through an epitaxy substrate and absorbable by a buffer layer to the buffer layer from a reverse side of the epitaxy substrate of the optical device wafer of the composite substrate, thereby breaking the buffer layer, and an optical device layer relocating step of peeling off the epitaxy substrate from the optical device layer, thereby relocating the optical device layer to the relocation substrate. In the buffer layer breaking step, irradiating conditions of the pulsed la-ser beam are changed for respective ring-shaped areas of the buffer layer, and the pulsed laser beam is applied to the optical device wafer under the changed irradiating conditions.

Abstract: A transferring method of transferring a plurality of optical device layers includes a transfer member bonding step, a buffer layer breaking step, a first optical device layer transferring step, an adhesive removing step, and a second optical device layer transferring step. In the transfer member bonding step, an optical device wafer and a transfer member are bonded to each other through an adhesive, and each spacing between adjacent ones of the optical device layers of the optical device wafer which each have been divided in a chip size is filled with the adhesive. In the adhesive removing step, at least part of the adhesive with which each spacing between the adjacent ones of the optical device layers has been filled is removed such that the optical device layers which have been embedded in an adhesive layer in the transfer member bonding step project from the adhesive layer.

Abstract: An optical device wafer processing method for transferring an optical device layer of an optical device wafer onto a transfer member includes: a dividing groove forming step of forming dividing grooves in a buffer layer; a transfer member joining step of joining the transfer member to a front surface of the optical device layer; and a laser beam applying step of applying a pulsed laser beam from a back surface side of a crystalline substrate. In the laser beam applying step, the buffer layer, or the buffer layer and part of the optical device layer, left without being divided in the dividing groove forming step, are modified in nature.

Abstract: A comparing method includes a processing trace forming step of positioning a condenser at a reference height and a plurality of heights by moving the condenser, and forming a plurality of processing traces in one surface of a workpiece by irradiating different positions of the one surface with a laser beam according to each of the heights, a calculating step of calculating at least one of an average of widths in a plurality of predetermined directions of each of the plurality of processing traces and an area ratio of each of the plurality of processing traces to a circle of a predetermined diameter by analyzing an image of the plurality of processing traces by an image analyzing section, and a comparing step of quantitatively comparing deviations of the plurality of processing traces from a predetermined shape on the basis of at least one of the average and the area ratio.

Abstract: A method of processing a wafer includes: preparing a support substrate that can transmit ultraviolet rays having a wavelength of 300 nm or shorter and can support the wafer thereon; integrating a face side of the wafer and the support substrate by sticking the face side of the wafer and the support substrate to each other with an UV-curable resin whose adhesive power can be lowered by ultraviolet rays applied thereto interposed therebetween, thereby integrally combining the wafer and the support substrate with each other; processing a reverse side of the wafer; destroying the UV-curable resin by applying a focused laser beam in an ultraviolet range having a wavelength of 300 nm or shorter from a support substrate side; and peeling off the support substrate from the face side of the wafer.

Abstract: A lift-off method transfers onto a transfer substrate an optical device layer of an optical device wafer in which the optical device layer is formed over a front surface of an epitaxy substrate through a GaN buffer layer. The lift-off method includes: bonding the transfer substrate onto a front surface of the optical device layer through a bonding layer to form a composite substrate; applying a pulsed laser beam of such a wavelength as to be transferred through the epitaxy substrate constituting the composite substrate but to be absorbed in the buffer layer from a back surface side of the epitaxy substrate, to break the buffer layer; and peeling the optical device layer from the epitaxy substrate and transferring the optical device layer onto the transfer substrate, after the buffer layer breaking step is performed.

Abstract: A transferring method of transferring a plurality of optical device layers includes a transfer member bonding step, a buffer layer breaking step, a first optical device layer transferring step, an adhesive removing step, and a second optical device layer transferring step. In the transfer member bonding step, an optical device wafer and a transfer member are bonded to each other through an adhesive, and each spacing between adjacent ones of the optical device layers of the optical device wafer which each have been divided in a chip size is filled with the adhesive. In the adhesive removing step, at least part of the adhesive with which each spacing between the adjacent ones of the optical device layers has been filled is removed such that the optical device layers which have been embedded in an adhesive layer in the transfer member bonding step project from the adhesive layer.

Abstract: A device transferring method for transferring a plurality of devices to a mounting substrate provided with a plurality of electrodes includes: a step of adhering an expandable tape to the plurality of devices formed on a front surface side of a substrate through a buffer layer; a step of applying a laser beam to the buffer layer from a back surface side of the substrate, to break the buffer layer; a step of moving the tape in a direction for spacing away from the substrate to separate the substrate and the plurality of devices from each other, thereby transferring the plurality of devices to the tape; a step of expanding the tape in such a manner that the layout of the plurality of devices corresponds to the layout of the plurality of electrodes; and a step of bonding the plurality of devices to the plurality of electrodes at once.

Abstract: A lift-off method includes a dividing step of dividing a buffer layer and an optical device layer stacked on a front side of a substrate to thereby form separate buffer layers and separate optical device layers, a transfer member bonding step of bonding a transfer member to a front side of the separate optical device layers, a buffer layer breaking step of applying a pulsed laser beam to the separate buffer layers to thereby break the separate buffer layers, and an optical device layer transferring step of transferring the separate optical device layers from the substrate to the transfer member. An energy density of each pulse of the pulsed laser beam is set to 1.0 to 5.0 mJ/mm2.

Abstract: A method for forming an adherend with an optical thin film through sticking the optical thin film to the adherend is provided. The method includes a substrate preparation step of preparing a substrate over which the optical thin film is formed with the intermediary of a bonding layer, a sticking step of sticking the adherend with lower heat resistance compared with quartz glass to the side of the optical thin film of the substrate, a bonding layer breaking step of breaking the bonding layer through carrying out irradiation with a laser beam with such a wavelength as to be transmitted through the substrate and be absorbed by the bonding layer from the surface of the substrate on the opposite side to the surface over which the optical thin film is formed, and a separating step of separating the adherend to which the optical thin film is stuck and the substrate.

Abstract: An optical device wafer processing method for transferring an optical device layer of an optical device wafer onto a transfer member includes: a dividing groove forming step of forming dividing grooves in a buffer layer; a transfer member joining step of joining the transfer member to a front surface of the optical device layer; and a laser beam applying step of applying a pulsed laser beam from a back surface side of a crystalline substrate. In the laser beam applying step, the buffer layer, or the buffer layer and part of the optical device layer, left without being divided in the dividing groove forming step, are modified in nature.

Abstract: A device transferring method for transferring a plurality of devices to a mounting substrate provided with a plurality of electrodes includes: a step of adhering an expandable tape to the plurality of devices formed on a front surface side of a substrate through a buffer layer; a step of applying a laser beam to the buffer layer from a back surface side of the substrate, to break the buffer layer; a step of moving the tape in a direction for spacing away from the substrate to separate the substrate and the plurality of devices from each other, thereby transferring the plurality of devices to the tape; a step of expanding the tape in such a manner that the layout of the plurality of devices corresponds to the layout of the plurality of electrodes; and a step of bonding the plurality of devices to the plurality of electrodes at once.

Abstract: A lift-off method transfers onto a transfer substrate an optical device layer of an optical device wafer in which the optical device layer is formed over a front surface of an epitaxy substrate through a GaN buffer layer. The lift-off method includes: bonding the transfer substrate onto a front surface of the optical device layer through a bonding layer to form a composite substrate; applying a pulsed laser beam of such a wavelength as to be transferred through the epitaxy substrate constituting the composite substrate but to be absorbed in the buffer layer from a back surface side of the epitaxy substrate, to break the buffer layer; and peeling the optical device layer from the epitaxy substrate and transferring the optical device layer onto the transfer substrate, after the buffer layer breaking step is performed.

Abstract: A method of processing a wafer includes: preparing a support substrate that can transmit ultraviolet rays having a wavelength of 300 nm or shorter and can support the wafer thereon; integrating a face side of the wafer and the support substrate by sticking the face side of the wafer and the support substrate to each other with an UV-curable resin whose adhesive power can be lowered by ultraviolet rays applied thereto interposed therebetween, thereby integrally combining the wafer and the support substrate with each other; processing a reverse side of the wafer; destroying the UV-curable resin by applying a focused laser beam in an ultraviolet range having a wavelength of 300 nm or shorter from a support substrate side; and peeling off the support substrate from the face side of the wafer.