Patent ID: 7498238
Filing Date: 2009-03-03
Classification: B23K,H01L,Y10T

Abstract:
1. A method for dicing a wafer including a first layer and a second layer, wherein the second layer is disposed on the first layer so that a front surface of the first layer contacts a backside surface of the second layer, the method comprising: forming a sealing film on the second layer to cover a front surface of the second layer and a part of the front surface of the first layer in a liquid -tightly manner, the part of the front surface of the first layer exposed from the second layer; cutting the first layer from a backside surface of the first layer along with a cutting line so that a notch is formed on the backside surface of the first layer; removing the sealing film from the second layer; irradiating a laser beam on the front surface of the second layer along with the cutting line after the removing the sealing film in such a manner that the laser beam is focused on an inside of the second layer in order to form a reforming region in the second layer by a multi photon absorption effect; and dividing the wafer along with the cutting line from the reforming region as a starting point of dividing.