Abstract: The safety key has a shank which is provided with a plurality of control surfaces for properly positioning tumblers and has a front end and a rear end. At a front end, the rotor of the associated locking cylinder has at least one further control surface, which interacts with a further control surface arranged at the rear end of the shank. The safety key is backward compatible and is relatively difficult to copy.

Abstract: The safety key has a shank which is provided with a plurality of control surfaces for properly positioning tumblers and has a front end and a rear end. At a front end, the rotor of the associated locking cylinder has at least one further control surface, which interacts with a further control surface arranged at the rear end of the shank. The safety key is backward compatible and is relatively difficult to copy.

Abstract: A chuck in a coating chamber in a CVD system has a hearth for providing heat to a substrate and an interchangeable chuck surface mounted on the hearth for supporting a substrate to be coated during processing. In preferred embodiment there are a plurality of chucks in a system. Excessive coating on surfaces in the CVD chamber other than substrate surfaces to be coated is substantially removed periodically by venting the chamber and replacing the interchangeable chuck faces. Also in a preferred embodiment, an interlocking feature operable by temperature is provided to secure the chuck faces during operation and to release them for interchanging. Also in a preferred embodiment heat transfer between the hearth and the chuck is enhanced by rings and grooves that increase surface area for heat transfer.

Abstract: A seal ring presses against a wafer on a CVD chuck continuously around the outer periphery of the wafer, and with sufficient force to hold the backside of the wafer against the chuck, so no CVD material may deposit on the backside of the wafer. The seal ring has one surface for contacting the frontside of the wafer and a second surface that extends close to the CVD chuck, so the edge of the wafer is also excluded from CVD coating. With use of the wafer seal ring apparatus and method, CVD coating is confined to the frontside of a wafer. In a preferred embodiment, an apparatus with a slide operated by a cam lever and a tension spring for moving the seal ring and pressing it against a wafer on a CVD chuck is used with each of multiple chucks attached to a rotatable turret within a CVD chamber.