Method of using a combination differential and absolute pressure transducer for controlling a load lock

DETAILED DESCRIPTION Accordingly, it is a general object of this invention to improve pressure monitoring and control of load locks in semiconductor fabrication process.
Another general object of this invention is to reduce contamination problems during load lock operations.
A more specific object of this invention is to provide controls that facilitate opening and closing the interior and exterior doors in load lock operations.
Another more specific object of this invention is to provide a pressure transducer for load lock control that is accurate and functional over the full range of operation from atmospheric pressures to very low evacuation pressures of 10.
sup.
-4 or lower.
Additional objects, advantages, and novel features of the invention shall be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by the practice of the invention.
The objects and the advantages may be realized and attained by means of the instrumentalities and in combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects, the apparatus of the present invention may comprise, but is not limited to, a combination differential and absolute pressure transducer apparatus for controlling a load lock that facilitates transfer of parts between a room at ambient atmospheric pressure and a vacuum processing chamber maintained at a pressure less than one (1) torr and that has an evacuatable load lock chamber, an exterior door positioned between the load lock chamber and the room, a interior door positioned between the load lock chamber and the processing chamber, a exterior door actuator that is responsive to an exterior door control signal to open or close the exterior door, an interior door actuator that is responsive to an interior door control signal to open or close the interior door, and a vacuum pump connected to the load lock chamber for evacuating the load lock chamber