| CPC H01L 21/78 (2013.01) | 18 Claims |
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1. A manufacturing method of a device chip by which a wafer in which a device is formed in each of a plurality of regions marked out by a plurality of streets formed in a lattice manner in a front surface of a substrate and front surfaces of the streets are coated with a film is divided into individual device chips along the streets, the manufacturing method comprising:
a film removal step of removing the film in regions corresponding to the streets;
a modified layer forming step of, after executing the film removal step, forming a modified layer along the streets inside the wafer through positioning a focal point of a laser beam with a wavelength having transmissibility with respect to the wafer inside the wafer and executing irradiation with the laser beam from a back surface side of the wafer along regions corresponding to the regions from which the film has been removed; and
a dividing step of giving an external force to the wafer and dividing the wafer along the streets into the individual device chips after executing the modified layer forming step with use of the modified layer as the origin of division of the wafer, wherein
in the film removal step, a distance from an end part of the street in a width direction to the region from which the film is to be removed is set equal to or shorter than a predetermined upper limit value to cause formation of a step between a region in which the substrate is exposed and a region coated with the film at an outer edge part of the device chip when the wafer is divided into the individual device chips in the dividing step.
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