Laser cleavage cutting method and system

A method for cleavage cutting a workpiece by emission of a laser beam, comprising the steps of:

• emitting the laser beam to a first surface of the workpiece to cleavage cut the workpiece;
• determining a temperature of a portion of the workpiece near a point of incidence of the laser beam on the first surface;
• and
• controlling the laser beam output on the basis of the determined temperature so as to keep constant the temperature of said portion;
• wherein said workpiece has a first region having a first absorptivity with respect to said laser beam, and a second region having a second absorptivity with respect to said laser beam, said first absorptivity being higher than said second absorptivity;
• and
• wherein said emitting step includes the steps of providing a semitransparent material between a source of the laser beam and said first surface at said first region, and emitting the laser beam to the first region through the semitransparent material.

A method for cleavage cutting a workpiece by emission of a laser beam, comprising the steps of:

• emitting the laser beam to a first surface of the workpiece to cleavage cut the workpiece;
• determining a temperature of a portion of the workpiece near a point of incidence of the laser beam on the first surface;
• and
• controlling the laser beam output on the basis of the determined temperature, so as to keep constant the temperature of said portion;
• wherein said emitting step includes the steps of emitting the laser beam to a cutting start point on the first surface for generating an initial crack at the cutting start point, and thereafter emitting the laser beam to the first surface from the cutting start point to a direction specified by the initial crack;
• wherein said step of emitting the laser beam to a cutting start point includes the step of locally cooling the cutting start point from a second surface of the workpiece opposite the first surface;
• and
• wherein the step of locally cooling the cutting start point is performed by contacting the second surface of the workpiece with a low-temperature solid.