Light irradiation type heat treatment method and heat treatment apparatus
A front surface of a semiconductor wafer is momentarily heated by irradiation with a flash of light from flash lamps. An upper radiation thermometer and a high-speed radiation thermometer unit measure a temperature of the front surface of the semiconductor wafer after the irradiation with the flash of light. The temperature data are sequentially accumulated, so that a temperature profile is acquired. An analyzer determines the highest measurement temperature of the semiconductor wafer subjected to the flash irradiation from the temperature profile to calculate a jump distance of the semiconductor wafer from a susceptor, based on the highest measurement temperature. If the calculated jump distance is greater than a predetermined threshold value, there is a high probability that the semiconductor wafer is significantly out of position, so that the transport of the semiconductor wafer to the outside is stopped.
1. A method of heating a substrate by irradiating the substrate with a flash of light, said method comprising the steps of:
(a) irradiating a front surface of a substrate supported by a susceptor in a chamber with a flash of light from a flash lamp;
(b) measuring a temperature of the front surface of said substrate at least after the irradiation with said flash of light to acquire a temperature profile; and
(c) analyzing a behavior of said substrate, based on said temperature profile acquired in said step (b) excluding time at which said flash lamp emits light,
wherein, in said step (c), a periodicity or amplitude of vibrations of said substrate is determined from the periodicity or amplitude of variations in measurement temperature appearing on a predetermined range of said temperature profile.
2. The method according to claim 1 , wherein transport of said substrate out of said chamber is stopped when the periodicity or amplitude of vibrations of said substrate determined in said step (c) is greater than a predetermined threshold value.