Patent ID: 8211719

Claim:
A method of processing a substrate, the method comprising: preparing a substrate, a first mask disposed adjacent to a first surface of the substrate, a condenser disposed adjacent to the first surface of the substrate, a second mask including a second light transmitting portion, and a photo detecting member including a photo detecting portion, wherein the first mask includes a first light transmitting portion that allows light to be transmitted therethrough, the condenser is configured to condense light that has passed through the first light transmitting portion toward the second light transmitting portion, the second light transmitting portion allows the light condensed by the condenser to be transmitted therethrough, and the photo detecting portion is configured to detect light that has passed through the second light transmitting portion; and forming a recess in the substrate by irradiation of a laser beam from a direction opposite to the first surface of the substrate, wherein the laser beam is detected by the photo detecting portion, and when an intensity of the laser beam detected by the photo detecting portion is equal to or larger than a specific intensity, the irradiation of the laser beam is stopped.