Laser annealing device

A laser annealing device that anneals an irradiation object including a substrate and amorphous silicon formed on the substrate, by irradiating the irradiation object with pulse laser light caused by pulse oscillation, the laser annealing device comprising:

• a CW laser device configured to emit continuous wave laser light caused by continuous oscillation to preheat the amorphous silicon;
• a first highly reflective mirror configured to guide the continuous wave laser light to the amorphous silicon with a high reflectance and transmit visible light other than the reflected continuous wave laser light with a high transmittance;
• a pulse laser device configured to emit the pulse laser light toward the preheated amorphous silicon;
• a second highly reflective mirror configured to guide the pulse laser light to the amorphous silicon with a high reflectance, transmit visible light with a high transmittance and couple an irradiation optical path of the continuous wave laser light with an irradiation optical path of the pulse laser light;
• and
• a control unit configured to control an irradiation energy density of the continuous wave laser light so as to preheat the amorphous silicon to have a predetermined target temperature less than a melting point thereof, and then stop output of the continuous wave laser light and control at least one of a fluence and a number of pulses of the pulse laser light so as to crystallize the preheated amorphous silicon.