PURPOSE: To accurately measure a temperature during heating by gas heating medium by forming it of a gas sealing plate, a fine circular gold wire and a sealing surface of ceramics.
CONSTITUTION: A temperature of a wafer 2 in vacuum is measured from a rear surface of an infrared ray thermometer 1 through a gas shielding plate 7 introduced into a pore 5 formed at a center of a heat block 3. In this case, the plate 7 is sealed with a fine circular gold wire 8. The other surface of the wire 8 is formed of a mirror-polished surface 9 of alumina. Thus, since a heating stage is formed of the plate 7, the wire 8 and the alumina 9, the temperature of the wafer 2 at the time of heating with gas can directly be measured. Accordingly, if a wafer which does not reach a desired temperature is discovered, it is further additionally heated or can be removed as a defective product from the beginning.
OKAMOTO AKIRA
KOBAYASHI HIDE
SHIMAMURA HIDEAKI
