| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a laser beam machining method capable of efficiently removing distortion caused by the heat of laser beams in the cut surface of a substrate in the laser beam machining method by which the substrate is irradiated with laser beams to cut the substrate one by one. <P>SOLUTION: A protective film 5 containing fluoride is deposited on a surface of a wafer 1. The wafer 1 with the protective film 5 being deposited thereon is held on a chuck table of a laser beam machining apparatus 10, and laser beams L are passed through the protective film 5 and applied to a division-scheduled line 2 on the surface of the wafer 1. Since the wafer 1 and the protective film 5 on the division-scheduled line 1 are melted and evaporated, a slit S is formed in the wafer 1. In this condition, fluoride in the protective film 5 is sublimed into plasma, and chemically reacted with silicon as a component of the wafer 1, and a cut surface 6 is etched. Thus, an area 7 where thermal distortion is caused is removed. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
