Abstract: An apparatus and a method for calibrating the position of a cassette indexer in a semiconductor process machine are described. The apparatus is constructed by a base plate, a top plate and at least two support members rigidly attaching the top plate to the base plate in a parallel relationship. On the bottom side of the top plate, is mounted at least two spaced-apart rows of distance sensors each having at least five sensors capable of sensing a distance in the cavity of the calibration apparatus. After a wafer blade is extended into the cavity of the apparatus, a sensor in the front row and a sensor in the back row can be used to sense a front-to-back tilt of the wafer blade, while two adjacent sensors in the same row can be used to sense a side-to-side tilt of the wafer blade.

Abstract: A modified air activated pressure valve is described, together with a method for its manufacture, that has a pressure sensitive switch located in the inlet chamber and in the outlet chamber. These pressure sensitive switches are preset by the user to output a finite voltage (typically about 5 volts) only when they are exposed to a pressure that exceeeds some value. The outputs of both switches may then be displayed, as needed. Additionally, a display circuit is provided that gives an output signal only when both the inlet and the outlet chambers are at or above their intended pressures.

Abstract: A heat pedestal is described for use in a physical vapor deposition/chemical vapor deposition system in which cooling gas, cooling water and heated gas are used to bring a semiconductor wafer to the desired low or high temperature. Use of the apparatus and method described leads to a very rapid transition from one temperature to another. Also achieved is a precise temperature control over a wide range yielding increased flexibility of process control.