Patent ID: 8229290

Claim:
A heat treatment apparatus for heating a substrate by irradiation thereof with light, said heat treatment apparatus comprising: a holder holding a substrate; a flash lamp emitting light to the substrate held by said holder; a switching element connected in series to said flash lamp, a capacitor, and a coil; a pulse-signal generator generating and outputting a pulse signal including one or more pulses to said switching element to control drive of said switching element; and a waveform setter setting a waveform of the pulse signal generated by said pulse-signal generator, said waveform setter setting a waveform that causes a surface temperature of the substrate held by said holder to change in such a manner that, with light emission from said flash lamp, said surface temperature is maintained during a certain period of time within a first temperature range that induces recovery of defects, and then with subsequent flashing light emission from said flash lamp, said surface temperature reaches a second temperature that is higher than said first temperature range and that induces activation of impurities.