Pillsbury, Winthrop LLP
Wafer heating device and method of controlling the same
 The present invention provides a wafer heating device which can improve uniformity of a temperature distribution within a surface area of a wafer, with a relatively simple structure. A wafer is supported on a susceptor of annular shape. A first heater of disc shape is disposed below the wafer, and a second heater of annular shape is disposed to surround the first heater. Radiation thermometers are arranged at a ceiling portion of a reaction chamber. The first radiation thermometer measures a temperature of a central area of the wafer, the second radiation thermometer measures a temperature of a peripheral area of the wafer, and the third radiation thermometer measures a temperature of the susceptor. The first heater and the second heater are controlled by independent closed loops. When a wafer is set on the susceptor, a power of the second heater is controlled by using a value measured by the second radiation thermometer as a feedback signal. When no wafer is set on the susceptor, the power of the second heater is controlled by using a value measured by the third radiation thermometer as a feedback signal. 
Toshiba Machine Co., Ltd Toshiba Ceramics Co., Ltd.
C C C C H H
C23C C30B C30B C23C H01L H01L
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Hideki Katsuyuki Hidenori Tadashi Shuji Hirofumi
Ito Iwata Takahashi Ohashi Tobashi Katsumata