Patent ID: 8603920

Claim:
A manufacturing method of a semiconductor device comprising: irradiating a laser beam on a single crystal silicon substrate, and scanning the laser beam on the substrate so that a portion of the substrate is poly crystallized, at least a part of the portion of the substrate that is poly crystallized being exposed on a surface of the substrate; and etching the portion of the substrate that is poly crystallized with an etchant, wherein, in the irradiating and scanning, a laser beam irradiation condition is such that a laser beam power is in a range between 0.1 watts and 1.2 watts, a scanning speed is 300 millimeters per second, and a frequency is 80 kHz, and the portion of the substrate that is poly crystallized includes a plurality of dome-shaped voids formed by the irradiating and the scanning under the laser beam irradiation condition.