To provide a dot marking device and a marking method therefor which enables to obtain a down mark shape which is minute but excellent in its visibility and correctly forms such a minute dot.
This device is equipped with a laser oscillator (10), a beam homonizer (20) to smoothen an energy distribution of a laser beam irradiated from the laser oscillator (10), a liquid crystal mask (30) to make the laser beam into a transmittal/non-transmittal status by a control driving of the laser beam compliance with a displayed pattern, a beam profile changing means (40) to transform an energy density distribution of the laser beam into a given distribution shape form corresponding to one dot of the liquid crystal mask (30), and a lens unit (50) to form an image of a beam transmitted through the crystal mark (30) onto a semi-conductor wafer surface by a dot unit. The maximum length of one liquid crystal mask dot is 50-2,000 μm and the maximum length of one dot by the lens unit is 1-10 μm. A peripheral wall of a hole opening of the dot mark formed by the device is cut in a sharply slanted shape like, for example, a barnacle shape and a difference of contrast between inside and outside of the hole is made extremely large.
MORI AKIRA
KOMURA TAKASUKE
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