摘要 |
A laser processing method for forming a deteriorated layer, which has been once molten and then re-solidified, in the inside of a wafer by applying a pulse laser beam capable of passing through the wafer to the wafer along a dividing line formed on the wafer, comprising: a protective tape affixing step for affixing a protective tape having gas permeability to one side of the wafer; a wafer holding step for holding the wafer having the protective tape affixed thereto on the chuck table of a laser beam machine in such a manner that the surface side onto which the protective tape has been affixed comes into contact with the chuck table; and a laser beam application step for applying a pulse laser beam capable of passing through the wafer from the other surface side of the wafer held on the chuck table with its focusing point set to a position near the one surface of the wafer to form the deteriorated layer exposed to the one surface along the dividing line in the inside of the wafer.
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