Heat treatment apparatus and heat treatment method for heating substrate by irradiating substrate with flashes of light
Radiant energy from a semiconductor wafer which is determined from the theoretical value of black body radiation and the actually measured result of an output from a photodiode are brought into correspondence with each other, and a table showing a correlation therebetween is acquired and stored on a magnetic disk. When a semiconductor wafer to be treated is irradiated with flashes of light from flash lamps, the photodiode receives radiant light emitted from the semiconductor wafer. A controller determines, from the output from the photodiode, the radiant energy emitted per unit time from the semiconductor wafer irradiated with flashes of light, based on the acquired table. The controller further determines the surface temperature of the semiconductor wafer from the determined radiant energy.
1. A method of heating a substrate by irradiating the substrate with flashes of light, comprising the steps of:
(a) acquiring a table showing a correlation between radiant energy per unit time from a substrate and an output from a photodiode receiving radiant light emitted from the substrate, said table showing a correlation between radiant energy per unit time from the substrate measured with a pyrometer and an output from said photodiode;
(b) irradiating the substrate with flashes of light from a flash lamp;
(c) determining, from the output from said photodiode, the radiant energy emitted per unit time from the substrate irradiated with flashes of light, based on said table; and
(d) determining the surface temperature of the substrate from the radiant energy per unit time from the substrate determined in said step (c).