Substrate dividing method

摘要

A substrate dividing method which can thin and divide a substrate while preventing chipping and cracking from occurring. This substrate dividing method comprises the steps of irradiating a semiconductor substrate 1 having a front face 3 formed with functional devices 19 with laser light while positioning a light-converging point within the substrate, so as to form a modified region including a molten processed region due to multiphoton absorption within the semiconductor substrate 1, and causing the modified region including the molten processed region to form a starting point region for cutting; and grinding a rear face 21 of the semiconductor substrate 1 after the step of forming the starting point region for cutting such that the semiconductor substrate 1 attains a predetermined thickness.

主权项

1. A semiconductor chip manufacturing method wherein a silicon substrate having a plurality of circuit devices formed in a matrix on a front face of the silicon substrate is divided into the circuit devices to obtain semiconductor chips, the method comprising:
irradiating the silicon substrate with laser light, thereby forming a plurality of modified regions embedded within the silicon substrate along each line of a plurality of cutting lines arranged in a grid running between the circuit devices which are adjacent to one another; reducing a thickness of the silicon substrate after forming the modified regions so that the silicon substrate is thinned so as to have a thickness not larger than 50 μm; and cutting the silicon substrate by reducing the thickness of the silicon substrate, or by fracture in the silicon substrate of which the thickness is reduced.