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 laser preheating control method is applied to a laser preheating control device. When a cutter processes a workpiece along a process path, a laser source of the device is provided to output a laser beam to the workpiece for selectively forming a laser spot on the workpiece surface. And according to a movement direction of the cutter, a laser controller of the device is provided to form the laser spot only on a preheating region of the workpiece, where in front of the cutter in the process path, for preheating the workpiece in the preheating region. As a result, the laser spot will not repeatedly heat the workpiece behind the cutter in the process path, and the qualitative change of the workpiece caused by repeating heating is preventable.

A laser preheating control method is applied to a laser preheating control device. When a cutter processes a workpiece along a process path, a laser source of the device is provided to output a laser beam to the workpiece for selectively forming a laser spot on the workpiece surface. And according to a movement direction of the cutter, a laser controller of the device is provided to form the laser spot only on a preheating region of the workpiece, where in front of the cutter in the process path, for preheating the workpiece in the preheating region. As a result, the laser spot will not repeatedly heat the workpiece behind the cutter in the process path, and the qualitative change of the workpiece caused by repeating heating is preventable.

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.

Shape memory alloys (SMAs) may be used for static rock splitting. The SMAs may be used as high-energy multifunctional materials, which have a unique ability to recover large deformations and generate high stresses in response to thermal loads.

A wafer producing apparatus includes an ingot grinding unit that grinds the upper surface of an ingot to planarize the upper surface, a laser irradiation unit that positions the focal point of a laser beam with such a wavelength as to be transmitted through the ingot to a depth corresponding to the thickness of a wafer to be produced from the upper surface of the ingot and irradiates the ingot with the laser beam to form a separation layer, a wafer separating unit that separates the wafer from the ingot, and a tray having a support part that supports the separated wafer.

A laser preheating control method is applied to a laser preheating control device. When a cutter processes a workpiece along a process path, a laser source of the device is provided to output a laser beam to the workpiece for selectively forming a laser spot on the workpiece surface. And according to a movement direction of the cutter, a laser controller of the device is provided to form the laser spot only on a preheating region of the workpiece, where in front of the cutter in the process path, for preheating the workpiece in the preheating region. As a result, the laser spot will not repeatedly heat the workpiece behind the cutter in the process path, and the qualitative change of the workpiece caused by repeating heating is preventable.

A laser preheating control method is applied to a laser preheating control device. When a cutter processes a workpiece along a process path, a laser source of the device is provided to output a laser beam to the workpiece for selectively forming a laser spot on the workpiece surface. And according to a movement direction of the cutter, a laser controller of the device is provided to form the laser spot only on a preheating region of the workpiece, where in front of the cutter in the process path, for preheating the workpiece in the preheating region. As a result, the laser spot will not repeatedly heat the workpiece behind the cutter in the process path, and the qualitative change of the workpiece caused by repeating heating is preventable.

A splitting apparatus comprising a first splitting blade having a smooth top with a width X and a shoulder angle of less than the friction angle, relative to a point in the middle of the top, and a second splitting blade disposed opposite the first splitting blade, the second splitting blade having a smooth top with a width Y and a shoulder angle of less than the friction angle, relative to a point in the middle of the top.

A splitting apparatus comprising a first splitting blade having a smooth top with a width X and a shoulder angle of less than the friction angle, relative to a point in the middle of the top, and a second splitting blade disposed opposite the first splitting blade, the second splitting blade having a smooth top with a width Y and a shoulder angle of less than the friction angle, relative to a point in the middle of the top.