Laser processing method

A laser processing method comprising the steps of:

• irradiating an object to be processed comprising a substrate and a laminate part disposed on a front face of the substrate with laser light while positioning a light-converging point at least within the substrate, thereby forming a modified region embedded within the substrate along each line of a plurality of cutting lines arranged in a grid with respect to the substrate, each substrate modified region forming a starting point region for cutting the object inside the object at a predetermined distance from a laser light incident face of the object;
• and
• after completion of forming the substrate modified regions, applying a stress to the object which causes cutting of the substrate and the laminate part along the cutting lines thereby generating a fracture in a thickness direction of the substrate from each starting point region that reaches a front face of the laminate part and a rear face of the substrate,
• wherein after the irradiation of the laser light is performed, each substrate modified region exists only within the substrate, and
• wherein the at least one of the front and back face of the substrate is a surface of the substrate into which the laser light enters.

A laser processing method comprising the steps of:

• irradiating an object to be processed comprising a substrate and a laminate part disposed on a front face of the substrate with laser light while positioning a light-converging point within the substrate, irradiating the object with laser light while positioning a light-converging point within the laminate part, thereby forming a modified region embedded within the substrate and a laminate part modified region embedded within the laminate part along each line of a plurality of cutting lines, each of the substrate modified regions and the laminate part modified regions forming a starting point region for cutting the object inside the object at a predetermined distance from a laser light incident face of the object;
• and
• cutting the substrate and the laminate part along the cutting lines when a fracture generated in a thickness direction of the substrate from each starting point region reaches a front face of the laminate part and a rear face of the substrate;
• wherein the substrate modified regions formed embedded within the substrate and the laminate part modified regions formed embedded within the laminate part are separate from each other,
• wherein after the irradiation of the laser light is performed, each substrate modified region exists only within the substrate, and
• wherein the at least one of the front and back face of the substrate is a surface of the substrate into which the laser light enters.

A laser processing method comprising the steps of:

• irradiating a substrate with laser light while positioning a light-converging point within the substrate, thereby forming a modified region only within the substrate along each line of a plurality of cutting lines, each modified region forming a starting point region for cutting the substrate inside the substrate at a predetermined distance from a laser light incident face of the substrate;
• and
• providing a laminate part on a front face of the substrate after forming the starting point regions;
• and
• cutting the substrate and the laminate part along the cutting lines when a fracture generated in a thickness direction of the substrate from each starting point region reaches a front face of the laminate part and a rear face of the substrate,
• wherein after the irradiation of the laser light is performed, each substrate modified region exists only within the substrate, and
• wherein the at least one of the front and back face of the substrate is a surface of the substrate into which the laser light enters.

A method of manufacturing a semiconductor device formed using a laser processing method, the manufacturing method comprising:

• irradiating an object to be processed comprising a substrate and a laminate part disposed on a front face of the substrate, the substrate and the laminate part having at least one semiconductor device, with laser light while positioning a light-converging point at least within the substrate, thereby forming a modified region embedded within the substrate along each line of a plurality of cutting lines arranged in a grid with respect to the substrate, each substrate modified region forming a starting point region for cutting the object, each substrate modified region being located inside the object at a predetermined distance from a laser light incident face of the object;
• and
• after completion of forming the substrate modified regions, applying a stress to the object causing cutting of the substrate and the laminate part along the cutting lines thereby generating a fracture in a thickness direction of the substrate from each starting point region that reaches a front face of the laminate part and a rear face of the substrate, wherein completion of the cutting step results in provision of at least one manufactured semiconductor device,
• wherein after the irradiation of the laser light is performed, each substrate modified region exists only within the substrate, and
• wherein the at least one of the front and back face of the substrate is a surface of the substrate into which the laser light enters.

A method of manufacturing a semiconductor device formed using a laser processing method, the manufacturing method comprising:

• irradiating an object to be processed comprising a substrate and a laminate part disposed on a front face of the substrate, the substrate and the laminate part having at least one semiconductor device, with laser light while positioning a light-converging point within the substrate, irradiating the object with laser light while positioning a light-converging point within the laminate part, thereby forming a modified region embedded within the substrate and a laminate part modified region embedded within the laminate part along each line of a plurality of cutting lines, each of the substrate modified region and the laminate part modified region forming a starting point region for cutting the object located inside the object at a predetermined distance from a laser light incident face of the object;
• and
• cutting the substrate and the laminate part along the cutting lines when a fracture generated in a thickness direction of the substrate from each starting point region reaches a front face of the laminate part and a rear face of the substrate, wherein completion of the cutting step results in provision of at least one manufactured semiconductor device;
• wherein the substrate modified regions formed embedded within the substrate and the laminate part modified regions formed embedded within the laminate part are separate from each other,
• wherein after the irradiation of the laser light is performed, each substrate modified region exists only within the substrate, and
• wherein the at least one of the front and back face of the substrate is a surface of the substrate into which the laser light enters.

A method of manufacturing a semiconductor device formed using a laser processing method, the manufacturing method comprising:

• irradiating a substrate with laser light while positioning a light-converging point within the substrate, thereby forming a substrate modified region only within the substrate along each line of a plurality of cutting lines, each modified region forming a starting point region for cutting the substrate, each modified region being located only inside the substrate at a predetermined distance from a laser light incident face of the substrate;
• providing a laminate part on a front face of the substrate after forming the starting point regions;
• and
• cutting the substrate and the laminate part along the cutting lines when a fracture generated in a thickness direction of the substrate from each starting point region reaches a front face of the laminate part and a rear face of the substrate, wherein completion of the cutting step results in provision of at least one manufactured semiconductor device,
• wherein after the irradiation of the laser light is performed, each substrate modified region exists only within the substrate, and
• wherein the at least one of the front and back face of the substrate is a surface of the substrate into which the laser light enters.