Abstract: A plate-shaped object processing method forms a through hole of a desired shape in a plate-shaped object. The method includes a through hole contour forming step of performing laser processing within the plate-shaped object along a contour of the through hole to be formed, by positioning, within the plate-shaped object, a focal point of a pulsed laser beam of a wavelength capable of passing through the plate-shaped object. The beam is applied along the contour of the through hole to be formed by a pulsed laser beam irradiation unit including a condenser applying the laser beams. A through hole is formed by breaking the laser-processed contour of the through hole and forming the through hole by positioning an ultrasonic transducer of an ultrasonic wave applying unit in correspondence with the contour of the through hole to be formed, and applying an ultrasonic wave.

Abstract: A separation apparatus for separating a composite substrate formed from a first substrate and a second substrate joined together includes an exfoliation unit for advancing into a boundary region between the first substrate and the second substrate of the composite substrate supported by a supporting face of a supporting base and a side face supporting unit to exfoliate the composite substrate into the first substrate and the second substrate. The exfoliation unit includes a wedge portion for advancing into the boundary region between the first substrate and the second substrate, an exfoliation member having a gas outlet open at a tip end of the wedge portion, and an exfoliation member advancing and retracting unit for advancing and retracting the wedge portion of the exfoliation member to and from the boundary region between the first substrate and the second substrate which configure the composite substrate.

Abstract: A method of dividing a single-crystal substrate along a plurality of preset division lines, includes a shield tunnel forming step of applying a pulsed laser beam having such a wavelength that permeates through the substrate along the division lines to form shield tunnels, each including a fine hole and an amorphous region shielding the fine hole, a protective member adhering step of adhering a protective member to the substrate before or after the shield tunnel forming step, and a grinding step of holding the protective member on the substrate, to which the shield tunnel forming step and the protective member adhering step are performed, on a chuck table of a grinding apparatus, grinding a reverse surface of the substrate to bring the substrate to a predetermined thickness, and dividing the substrate along the division lines along which the shield tunnels have been formed.

Abstract: A single-crystal substrate having a film deposited on a surface thereof is processed to divide the single-crystal substrate along a plurality of preset division lines, including a shield tunnel forming step of applying a pulsed laser beam having such a wavelength that permeates through the single-crystal substrate to the single-crystal substrate from a reverse side thereof along the division lines to form shield tunnels, each including a fine hole and an amorphous region shielding the fine hole, in the single-crystal substrate along the division lines, a film removing step of removing the film deposited on the single-crystal substrate along the division lines, and a dividing step of exerting an external force on the single-crystal substrate to which the shield tunnel forming step and the film removing step are performed to divide the single-crystal substrate along the division lines along which the shield tunnels have been formed.

Abstract: Disclosed herein is a processing method of a single-crystal substrate having a film formed on a front side or a back side thereof to divide the single-crystal substrate along a plurality of preset division lines. The method includes a film removing step of removing the film along the division lines, a shield tunnel forming step of applying a pulsed laser beam having a wavelength which permeates through the single-crystal substrate along the division lines to form shield tunnels, each including a fine hole and an amorphous region shielding the fine hole, in the single-crystal substrate along the division lines, and dividing step of exerting an external force on the single-crystal substrate to which the shield tunnel forming step is performed to divide the single-crystal substrate along the division lines.

Abstract: A lift-off method transfers an optical device layer of an optical device wafer onto a transfer substrate. The optical device layer is stacked on a front face of an epitaxy substrate with a buffer layer provided therebetween. A complex substrate formation step forms a complex substrate by joining the transfer substrate to a front face of the optical device layer of the optical device wafer with an adhesive. A buffer layer destruction step irradiates a laser beam at a wavelength that penetrates the epitaxy substrate and is absorbed by the buffer layer from a rear side of the epitaxy substrate of the complex substrate so as to destroy the buffer layer. An optical device layer transfer step peels off the epitaxy substrate and transfers the optical device layer onto the transfer substrate.

Abstract: A method of processing a single-crystal member includes setting the peak energy density of a pulsed laser beam to a value in a range from 1 TW/cm2 to 100 TW/cm2, and applying the pulsed laser beam to the single-crystal member while positioning a converged point of the pulsed laser beam at a predetermined position spaced from an upper side of the single-crystal member to grow fine a hole and a amorphous region shielding the fine hole from the upper side of the single-crystal member, thereby forming a shield tunnel in the single-crystal member.

Abstract: A laser processing apparatus includes a plasma detecting unit for detecting a wavelength of plasma light generated by applying a pulsed laser beam from a laser beam applying unit to a workpiece. The plasma detecting unit includes a bandpass filter for passing only the wavelength of plasma light generated from a first material and a photodetector for detecting the light passed through the bandpass filter. A light intensity signal is output to a controller. The controller controls the laser beam applying unit so that the amplitude of a light intensity is detected according to the light intensity signal output from the photodetector. The pulsed laser beam is stopped after the amplitude of the light intensity is decreased to a predetermined value and a predetermined number of shots of the pulsed laser beam has been applied.

Abstract: A laser beam irradiation unit of a laser processing apparatus includes a laser oscillator which oscillates a laser beam, an output power adjustment unit which adjusts output power of the laser beam, a condenser which converges the laser beam and irradiates the converged laser beam upon a workpiece held on a chuck table, and a rocking unit which is disposed between the laser oscillator and the condenser and rocks the laser beam oscillated by the laser oscillator in an X-axis direction and a Y-axis direction. A controller has a memory in which a processing controlling program for carrying out processing for the workpiece held on the chuck table and a marking controlling program for carrying out marking for the workpiece are stored. The processing controlling program and the marking controlling program are selected by a program selection signal from an inputting unit.

Abstract: A laser processing method for forming a laser processed hole in a workpiece having a first member including a first material and a second member including a second material, the laser processed hole extending from the first member to the second member, the laser processing method including: applying a pulsed laser beam to the workpiece; using a plasma detecting means to detect the wavelength of plasma light generated by applying the pulsed laser beam to the workpiece; controlling, via a controller, a laser beam applying means according to a detection signal from the plasma detecting means; and stopping the application of the pulsed laser beam when both: (i) the light intensity detected by a first photodetector is decreased, and (ii) the light intensity detected by a second photodetector is increased to a peak value and next decreased to a given value that is slightly less than the peak value.

Abstract: A wafer processing method for dividing a wafer along a plurality of division lines to obtain a plurality of individual chips. The wafer processing method includes a filament forming step of applying a pulsed laser beam having a transmission wavelength to the wafer along each division line in the condition where the focal point of the pulsed laser beam is set inside the wafer in a subject area to be divided, thereby forming a plurality of amorphous filaments inside the wafer along each division line, and an etching step of etching the amorphous filaments formed inside the wafer along each division line by using an etching agent to thereby divide the wafer into the individual chips along the division lines.

Abstract: A wafer is formed with a plurality of division lines on a front surface of a single crystal substrate having an off angle and formed with devices in a plurality of regions partitioned by the division lines. The wafer is processed by setting a numerical aperture (NA) of a focusing lens for focusing a pulsed laser beam so that a value obtained by dividing the numerical aperture (NA) by a refractive index (N) of the single crystal substrate falls within the range from 0.05 to 0.2. The pulsed laser beam is applied along the division lines, with a focal point of the pulsed laser beam positioned at a desired position from a back surface of the single crystal substrate, so as to form shield tunnels each composed of a pore and a pore-shielding amorphous portion along the division lines from the focal point positioned inside the single crystal substrate.

Abstract: A wafer processing method for forming a via hole in a wafer. The wafer processing method includes a filament forming step of applying a pulsed laser beam to the wafer, the pulsed laser beam having a transmission wavelength to the wafer, in the condition where the focal point of the pulsed laser beam is set inside the wafer in a subject area where the via hole is to be formed, thereby forming an amorphous filament inside the wafer in the subject area, and an etching step of etching the amorphous filament formed inside the wafer by using an etching agent to thereby form the via hole inside the wafer.

Abstract: A laser processing method of applying a pulsed laser beam having a repetition frequency of 20 kHz or more to a workpiece to thereby process the workpiece. The relation between the wavelength of the pulsed laser beam and the pulse width generating no cracks is determined by experiment on the basis of the absorption edge of the workpiece, thereby setting the processing conditions. The relation between various set values for the wavelength and the limits of the pulse width is plotted to prepare a graph having a vertical axis representing the wavelength and a horizontal axis representing the pulse width. The pulsed laser beam is applied in the region below a curve obtained by connecting the limits of the pulse width at the various set values for the wavelength.

Abstract: A laser processing method of applying a laser beam to a workpiece having a plurality of members, thereby forming a laser processed groove on the workpiece. The laser processing method includes the steps of setting a plurality of processing conditions respectively corresponding to a plurality of different materials forming the plurality of members constituting the workpiece, detecting the wavelengths of plasma lights generated by applying the laser beam to the plurality of members constituting the workpiece, selecting any suitable one of the processing conditions corresponding to any one of the members corresponding to the wavelength of plasma lights detected above, and applying the laser beam under the processing condition selected above.

Abstract: A laser processing method of applying a pulsed laser beam to a single crystal substrate to thereby process the single crystal substrate. The laser processing method includes a numerical aperture setting step of setting the numerical aperture (NA) of a focusing lens for focusing the pulsed laser beam so that the value obtained by dividing the numerical aperture (NA) of the focusing lens by the refractive index (N) of the single crystal substrate falls within the range of 0.05 to 0.

Abstract: A chip having a desired shape is formed from a platelike workpiece. The chip manufacturing method includes a shield tunnel forming step of applying a pulsed laser beam to the workpiece from a focusing unit included in a pulsed laser beam applying unit along the contour of the chip to be formed, with the focal point of the pulsed laser beam set at a predetermined depth from the upper surface of the workpiece, thereby forming a plurality of shield tunnels inside the workpiece along the contour of the chip to be formed. Each shield tunnel has a fine hole and an amorphous region formed around the fine hole for shielding the fine hole. In a chip forming step, ultrasonic vibration is applied to the workpiece to break the contour of the chip where the shield tunnels have been formed, thereby forming the chip from the workpiece.

Abstract: A laser processing method of applying a pulsed laser beam to a workpiece formed from a transparent member, thereby performing laser processing to the workpiece. The laser processing method includes a first laser processing step of applying a first pulsed laser beam to a subject area of the workpiece to roughen the subject area and a second laser processing step of applying a second pulsed laser beam to the roughened subject area immediately after performing the first laser processing step, thereby forming a recess in the subject area. The first and second laser processing steps are repeated to thereby form a continuous groove in the subject area.

Abstract: A lift-off method for transferring an optical device layer in an optical device wafer to a transfer substrate, the optical device layer being formed on the front side of an epitaxy substrate through a buffer layer. A transfer substrate is bonded through a bonding layer to the front side of the optical device layer of the optical device wafer, thereby forming a composite substrate. A pulsed laser beam having a wavelength transmissive to the epitaxy substrate and absorptive to the buffer layer is applied from the back side of the epitaxy substrate to the buffer layer, thereby breaking the buffer layer, and the epitaxy substrate is peeled from the optical device layer, thereby transferring the optical device layer to the transfer substrate. Ultrasonic vibration is applied to the composite substrate in transferring the optical device layer.

Abstract: A wafer is formed by slicing a single crystal ingot and removing crystal strains remaining in a peripheral portion of the wafer. In the crystal strain removing step, a laser beam having such a wavelength as to be transmitted through the wafer is applied to the wafer from one side of the wafer in positions located along the margin of the wafer and spaced a predetermined distance inward from the margin, to cause growth of fine holes and amorphous regions shielding the fine holes, over the range from one side to the other side of the wafer, whereby shield tunnels are formed in an annular pattern. Then, an external force is applied to the wafer along the shield tunnels so as to break the wafer in the region of the shield tunnels, thereby removing the peripheral wafer portion where the crystal strains are remaining.