Abstract: A monitoring device for determining the presence or absence of wafer-like objects in a carrier having a plurality of shelves, each shelf being constructed to support one such object in an orientation normal to a carrier axis. The monitoring device may advantageously be used in an apparatus for handling wafer-like objects in a self-contained environment. The monitoring device includes a first detector capable of detecting movement of a body past the detector and generating a corresponding first signal. A translation member is physically coupled to the carrier, such that movement of the translation member results in movement of the carrier. The translation member is moved such that the carrier, and any objects such as wafers supported in the carrier, move along the carrier axis past the first detector. As the translation member moves, a position signal is generated, such that the position signal encodes the position of the translation member.

Abstract: A device for centering an object and rotating it to a desired angular position relative to a discerning feature. The centration device is particularly adapted for use as a station in a semiconductor wafer handling apparatus, and includes a rotatably driven chuck on which a wafer may be placed by a robot manipulator arm. The perimeter of the wafer is rotated between a light source and a linear array of charge coupled device elements, casting a shadow on the light sensitive elements as the wafer is rotated. A processor connected to the charge couple devices and to an angular position encoder on a shaft of the chuck rotating the wafer is operative to collect data relating the displacement of the perimeter from a reference point to the angular position of the wafer. The processor determines from the data a distance over which the wafer should be shifted on the chuck to center it relative to the reference point.

Abstract: An apparatus for handling or inspecting a sensitive material such as a semiconductor wafer or mask in a self-contained environment, such that the apparatus can be used outside a clean room. The apparatus incorporates a standardized mechanical interface for transferring the wafers or other sensitive material to and from the apparatus in a box having a cover, a bottom, a latch assembly releasably connecting and sealing the cover to the bottom, and a carrier such as a cassette for supporting the wafers. The apparatus includes a base and a canopy attached to the base so as to create an enclosed space between the base and canopy. The canopy includes a port door releasably secured to the canopy, the port door including an upper surface adapted for supporting the bottom of the box. The apparatus also includes a manipulator and electronic control for controlling the manipulator.