Holding mechanism for a susceptor in a substrate processing reactor

Abstract

A collet assembly coupled to a rotary-linear drive unit allows easily placement of a susceptor shaft within a collet of the collet assembly when the collet assembly is in a first position. After the susceptor shaft is placed into the collet, the collet assembly is retracted to a second position by a spring force acting on a collet draw bar that is coupled to the collet. As the collet assembly is retracted by the spring force, the collet is closed about the susceptor shaft by the interaction between the collet and a collet spindle in which the collet is moveably mounted. As the collet closes, the collet assembly exerts a pressure about a circumferential surface of a susceptor shaft that in turn holds the susceptor shaft firmly in place within the collet, i.e., holds the susceptor shaft stationary within the collet. Consequently, when the susceptor shaft is rotated by the rotary-linear drive unit, there is no wobble associated with the rotary movement of the susceptor shaft. To disengage the collet, the rotary-linear drive unit provides a force that moves the collet upwards which in turn causes the collet to release the pressure on the susceptor shaft. Thus, a linear motion is used to engage and disengage the collet, while a rotary motion is used to turn the susceptor shaft.