초록 ▼

A system for locating and positioning wafers includes a wafer shuttle, a spindle, and a position sensor. The wafer shuttle retrieves wafers from a storage location, typically a wafer cassette, and transports the wafers to the spindle. The wafers are then incrementally rotated on the spindle, and the

A system for locating and positioning wafers includes a wafer shuttle, a spindle, and a position sensor. The wafer shuttle retrieves wafers from a storage location, typically a wafer cassette, and transports the wafers to the spindle. The wafers are then incrementally rotated on the spindle, and the distance between the center of rotation and the periphery of the wafer along a linear path is measured. By using three such measurements, the distance and angle with which the center of the wafer is offset from the center of rotation may be calculated. The wafer can then be centered on the spindle by rotation and translated a proper distance by the wafer shuttle. Usually, the wafers will be further rotationally oriented so that the crystal lattice lies in a desired direction.

대표청구항 ▼

A system for positioning a circular workpiece, said system comprising: means for conveying the workpiece along a linear path; means for rotating the workpiece about a center of rotation located on the linear path; means for measuring the distance along the linear path between the center of rotation

A system for positioning a circular workpiece, said system comprising: means for conveying the workpiece along a linear path; means for rotating the workpiece about a center of rotation located on the linear path; means for measuring the distance along the linear path between the center of rotation and the periphery of the workpiece; and means for determining the offset between the center of rotation and the center of the workpiece based on the measured distance between the center of rotation and the periphery of the workpiece at at least three different angles of rotation.