| 摘要 |
PURPOSE:To unify a temperature distribution in each part of a substance to be treated, by controlling the distribution ratio of thermal output of a plurality of control units of a heating means so that a temperature at a representative point of the substance to be treated accords with a prescribed set value and that a temperature difference between temperatures at points other than the representative point is made minimum. CONSTITUTION:A control unit P starts the regulation of thermal outputs of heating zones R1, R2 and R3 on the basis of a difference between a temperature at a position C (representative point) of a temperature sensor 7 corresponding to the central portion of a wafer 3 and an aimed regular heating temperature, for instance. When there occurs a difference between the temperature at said position and temperatures observed at a position E and further a position M which correspond to the peripheral portion of the wafer 3, a control is conducted to minimize the temperature difference between the central and peripheral portions of the wafer 3 by changing sequentially the distribution ratio of thermal output in the heating zones R1-R3 through the intermediary of output distributing elements D1-D3. By this method, it is prevented that the temperature distribution in each part of the wafer 3 becomes nonuniform in a rising process of temperature. |
