Materials Research Corporation

Other

Hiroichi Ishikawa

Michael S Kolesa

Richard C Edwards

A wafer processing cluster tool, having one or more load-locks, is provided with one or more batch preheating modules that receive wafers only from the cluster tool transport module at the internal vacuum pressure of the machine. The loading, unloading, handling and processing of wafers in the machine can occur while other wafers are being preheated. The preheat module has a vertically moveable rack and is loaded with various sized batches of wafers with no vacant positions between them. Wafer shaped shields may occupy positions adjacent top and bottom wafers to cause them to heat the same as other wafers in the rack. Infrared lamps positioned outside of quartz windows heat wafers in the preheat module. The rack may rotate to improve heating uniformity. Temperature sensors, such as pyrometers, that do not contact the wafers being preheated, measure temperature for control of the heating of the lamps.

Wafer processing cluster tool batch preheating and degassing method

A method of measuring and controlling the temperature of articles stacked in parallel in a chamber. A pyrometer is positioned outside of a chamber and directed, either directly or with mirrors, through a window in the chamber wall 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.

Pyrometer temperature measurement of plural wafers stacked on a

A method and apparatus are provided for measuring the temperature of articles such as semiconductor wafers in a sealed chamber of a processing apparatus such as a batch preheating module of a semiconductor wafer processing cluster tool. Wafers of generally known nominal diameter and coefficient of thermal expansion are placed at a known initial temperature into a processing chamber which is then sealed. A pair of beams of parallel light are passed by opposite edges of the wafer and the uninterrupted light from both beams are detected and summed. When the wafer is heated in processing, light from the beams is measured again. Expansion of the wafers changes the amount of uninterrupted light detected, and the changed amount of light is measured. From the measurement, the initial temperature, the nominal diameter and the known coefficient of expansion, processing temperature is calculated and displayed or used to control chamber heaters. The beams are preferably angled to the wafer planes so that vertical alignment is not critical and so that the beams are interrupted by a single wafer when in a stack. The signals from the detectors can be used to vertically position the wafers.

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Mahwah, NJ, United States of America

Hiroichi Ishikawa