PYROMETER TEMPERATURE MEASUREMENT OF PLURAL WAFERS STACKED IN A PROCESSING CHAMBER

摘要

2102795 9221147 PCTABS00017 An apparatus for batch processing flat articles such as semiconductor wafers (14) in a sealed chamber (12) and a method of measuring and controlling the temperature of articles stacked in parallel in the chamber. A pyrometer (53) is positioned outside of the chamber and directed, either directly or with mirrors, through a window (51) in the chamber wall (11) so that only energy from wafers removed from the ends of the stack is received by the pyrometer. The pyrometer is inclined at an angle so that substantially all energy from the opposite side of the stack and reflected through spaces between facing parallel pairs of wafer surfaces will have been reflected a large number of times by the wafers before entering the pyrometer. Thus, regardless of the emissivity or transmissivity of the wafers, the energy incident upon the pyrometer will approach that emitted by a black body of the same temperature as the wafers, and the temperature read by the pyrometer will be independent of the emissivity or transmissivity of the wafers.