Thermal processing method and thermal processing apparatus through light irradiation
A susceptor is preheated through light irradiation by a halogen lamp before the first semiconductor wafer of a lot as a processing target is transferred into a chamber. The temperature of the susceptor is measured by a radiation thermometer. A control unit is configured to control the output of the halogen lamp so that the temperature of the susceptor reaches a stable temperature based on a result of the measurement of the temperature of the susceptor by the radiation thermometer. The stable temperature of the susceptor is the temperature of the susceptor when the temperature of the susceptor is risen to a constant temperature by continuously performing light irradiation heating on a plurality of semiconductor wafers in the chamber without heating the susceptor.
1. A thermal processing method of heating a substrate by irradiating the substrate with light, the method comprising the steps of:
(a) transferring a substrate into a chamber to place the substrate on a susceptor;
(b) irradiating the substrate placed on said susceptor with light;
(c) measuring the temperature of said susceptor before the first substrate of a lot is transferred into said chamber; and
(d) heating said susceptor based on a result of the measurement in said step (c), wherein
when a stable temperature is set as the temperature of said susceptor when the temperature of said susceptor has risen to a constant temperature by continuously irradiating a plurality of substrates of a lot, with light to heat the substrates without heating said susceptor,
in said step (d), said susceptor is heated so that the temperature of said susceptor reaches said stable temperature.
2. The thermal processing method according to claim 1 , wherein
in said step (c), temperature is measured at a plurality of places on said susceptor, and
in said step (d), heating control is performed for each region including one of said plurality of places.
3. The thermal processing method according to claim 1 , wherein, in said step (b), said substrate is irradiated by a flash lamp with flash light from one side of said chamber.
4. The thermal processing method according to claim 3 , wherein
in said step (b), said substrate is further irradiated by a halogen lamp with light from the other side of said chamber, and
in said step (d), said susceptor is heated through light irradiation by said halogen lamp.