Light irradiation type heat treatment method and heat treatment apparatus

A heat treatment apparatus for irradiating a substrate with a flash of light to heat the substrate, comprising:

• a chamber for receiving a substrate therein;
• a continuous lighting lamp for irradiating said substrate with light to preheat said substrate;
• a flash lamp for irradiating a front surface of said substrate with a flash of light to flash-heat said substrate;
• and
• a first radiation thermometer including a photovoltaic detector and for measuring a temperature of said substrate,
• wherein said first radiation thermometer executes a first measurement mode and a second measurement mode in parallel to measure the temperature of said substrate,
• said first measurement mode being a measurement mode in which data acquisition is performed at a first sampling interval,
• said second measurement mode being a measurement mode in which data acquisition is performed at a second sampling interval shorter than said first sampling interval.

A heat treatment apparatus for irradiating a substrate with a flash of light to heat the substrate, comprising:

• a chamber for receiving a substrate therein;
• a continuous lighting lamp for irradiating said substrate with light to preheat said substrate;
• a flash lamp for irradiating a front surface of said substrate with a flash of light to flash-heat said substrate;
• and
• a first radiation thermometer including a photovoltaic detector and for measuring a temperature of said substrate,
• wherein a process using a digital filter is performed on a signal outputted from said photovoltaic detector.