A low voltage laser device having an active region configured for one or more selected wavelengths of light emissions.

A wafer producing method includes a peel-off layer forming step of applying a laser beam of a wavelength passing through a hexagonal single crystal ingot with a focal point of the laser beam positioned at a depth corresponding to a thickness of a wafer to be produced from an end face of the hexagonal single crystal ingot to form a peel-off layer, a production history forming step of applying a laser beam of a wavelength passing through the wafer with a focal point of the laser beam positioned inside the wafer at a position corresponding to each of a plurality of devices to be formed on a front surface of the wafer to form a production history, and a wafer peeling step of peeling off the wafer from the hexagonal single crystal ingot.

A wafer is processed by irradiating a region to be divided with a pulse laser beam with a wavelength having absorbability to generate a thermal stress wave and propagate the wave to the inside of the region to be divided. A crushed layer is formed by executing irradiation, with a pulse laser beam with a wavelength having transmissibility with respect to the wafer, matching with a time when the thermal stress wave is generated and reaching a depth position at which a point of origin of dividing is to be generated at a sonic speed according to the material of the wafer. Absorption of the pulse laser beam with the wavelength having the transmissibility in a region in which the band gap is narrowed due to a tensile stress of the thermal stress wave forms a crushed layer that serves as the point of origin of dividing.

A wafer producing method for producing a wafer from a semiconductor ingot includes a thermal stress wave generating step of applying a pulsed laser beam having a wavelength that is absorbable by the semiconductor ingot to the semiconductor ingot held on the chuck table to generate a thermal stress wave and a fracture layer forming step of applying a pulsed laser beam having a wavelength that is transmittable through the semiconductor ingot to the semiconductor ingot in synchronism with a time during which the thermal stress wave reaches a position corresponding to a thickness of a wafer to be produced from the semiconductor ingot, causing the pulsed laser beam whose wavelength is transmittable through the semiconductor ingot to be absorbed in a region where a band gap is reduced by a tensile stress of the thermal stress wave.

The invention provides a method for laser modification of a sample to form a modified region at a target location within the sample. The method comprises positioning a sample in a laser system for modification by a laser; measuring tilt of a surface of the sample through which the laser focusses; using at least the measured tilt to determine a correction to be applied to an active optical element of the laser system; applying the correction to the active optical element to modify wavefront properties of the laser to counteract an effect of coma on laser focus; and laser modifying the sample at the target location using the laser with the corrected wavefront properties to produce the modified region.

The invention relates to a method for separating at least one solid-state layer (4) from at least one solid (1). The method according to the invention includes the steps of: producing a plurality of modifications (9) by means of laser beams in the interior of the solid (1) in order to form a separation plane (8); producing a composite structure by arranging or producing layers and/or components (150) on or above an initially exposed surface (5) of the solid (1), the exposed surface (5) being part of the solid-state layer (4) to be separated; introducing an external force into the solid (1) in order to create stresses in the solid (1), the external force being so great that the stresses cause a crack to propagate along the separation plane (8), wherein the modifications for forming the separation plane (8) are produced before the composite structure is produced.

Provided are a method of fragmenting or a method of generating cracks in a semiconductor material, and a method of producing semiconductor material lumps, which can prevent contamination from an electrode material accompanied by application of a high-voltage pulse; in a method of fragmenting or generating cracks in the semiconductor material by applying high-voltage pulse to the semiconductor material disposed in liquid, new fluid is supplied towards at least one of a part on which the high-voltage pulse is applied and a vicinity of an electrode part, and the new fluid and a part of the liquid are drawn from the liquid and discharged.

A method of producing a wafer includes a peel-off layer forming step to form a peel-off layer in a hexagonal single-crystal ingot by applying a laser beam having a wavelength transmittable through the hexagonal single-crystal ingot while positioning a focal point of the laser beam in the hexagonal single-crystal ingot at a depth corresponding to the thickness of a wafer to be produced from an end face of the hexagonal single-crystal ingot, an ultrasonic wave generating step to generate ultrasonic waves from an ultrasonic wave generating unit positioned in facing relation to the wafer to be produced across a water layer interposed therebetween, thereby to break the peel-off layer, and a peel-off detecting step to detect when the wafer to be produced is peeled off the hexagonal single-crystal ingot by positioning an image capturing unit sideways of the wafer to be produced.

Silicon carbide (SiC) wafers and related methods are disclosed that include intentional or imposed wafer shapes that are configured to reduce manufacturing problems associated with deformation, bowing, or sagging of such wafers due to gravitational forces or from preexisting crystal stress. Intentional or imposed wafer shapes may comprise SiC wafers with a relaxed positive bow from silicon faces thereof. In this manner, effects associated with deformation, bowing, or sagging for SiC wafers, and in particular for large area SiC wafers, may be reduced. Related methods for providing SiC wafers with relaxed positive bow are disclosed that provide reduced kerf losses of bulk crystalline material. Such methods may include laser-assisted separation of SiC wafers from bulk crystalline material.

Silicon carbide (SiC) wafers and related methods are disclosed that include intentional or imposed wafer shapes that are configured to reduce manufacturing problems associated with deformation, bowing, or sagging of such wafers due to gravitational forces or from preexisting crystal stress. Intentional or imposed wafer shapes may comprise SiC wafers with a relaxed positive bow from silicon faces thereof. In this manner, effects associated with deformation, bowing, or sagging for SiC wafers, and in particular for large area SiC wafers, may be reduced. Related methods for providing SiC wafers with relaxed positive bow are disclosed that provide reduced kerf losses of bulk crystalline material. Such methods may include laser-assisted separation of SiC wafers from bulk crystalline material.