| 摘要 |
<p>A laser beam (L), i.e., a pulsed laser beam, is radiated with a pulse width of 31ns-54ns and a pulse pitch of 7.5µm-10µm, to form a modified region (7) to be a cut start point along a planned cut line (5) on a GaAs substrate (12). Thus, the modified region (7) formed on the GaAs substrate (12) along the planned cut line (5) permits cracks to be easily generated in the thickness direction of the processing object (1). Therefore, the modified region (7) having extremely high function as the cut start point is formed on the board-like processing object (1) provided with the GaAs substrate (12).</p> |
