| CPC B23K 26/53 (2015.10) [B23K 26/046 (2013.01); B23K 26/0622 (2015.10); H01L 21/78 (2013.01); B23K 2101/40 (2018.08)] | 13 Claims |
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1. A laser processing apparatus configured to form modified regions in an object to be processed along cutting lines by focusing laser light on the object, the object including a sapphire substrate having a C-plane as a main surface, the laser processing apparatus comprising:
a laser light source configured to emit the laser light;
a spatial light modulator configured to modulate the laser light emitted from the laser light source; and
a focusing optical system configured to focus the laser light modulated by the spatial light modulator on the object, wherein,
provided that a state in which aberration correction is performed to counteract spherical aberration generated at a focusing position of the laser light is defined as an ideal focusing state, and that an aberration correction amount in the ideal focusing state is defined as an ideal aberration correction amount,
the spatial light modulator performs aberration correction by a first aberration correction amount smaller than the ideal aberration correction amount when the modified region is formed along a first cutting line along an a-axis direction of the sapphire substrate, and
the spatial light modulator performs aberration correction by a second aberration correction amount smaller than the ideal aberration correction amount and different from the first aberration correction amount when the modified region is formed along a second cutting line along an m-axis direction of the sapphire substrate.
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