| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for dividing a wafer comprising dividing a wafer along the streets into individual devices, the surface of the streets being coated with a film, where division can be performed without leaving the film.SOLUTION: A wafer dividing method includes: a film dividing step where a film 24 is divided along the streets 22 by irradiating a laser light of a wavelength, which is absorbed by the film, from a surface side of the wafer 2 and forming a laser processed groove 240; a rear surface grinding step where the wafer is fabricated to a prescribed thickness by grinding a rear surface of a substrate; a modified layer forming step where a modified layer 210 is formed inside the substrate along the streets and a crack 211 is generated reaching from the modified layer to the laser processed groove formed on the wafer surface by irradiating a laser light of a wavelength, which transmits through the substrate, along the streets from a rear surface side of the wafer with a focal point positioned inside the substrate; and a fracturing step where the wafer is fractured along the streets by applying external force to the wafer. |
