Abstract: An annular ring assembly is provided in which mechanical elements of the retaining ring assembly maintain strict planar flatness, rigidity, high tolerances and surface stability control. Additionally, glues, adhesives, and epoxies are eliminated from the construction of the plastic retaining and backing ring assembly. Further, adverse chemical reaction and contamination from adhesives that are typically in direct contact with chemical slurry and substrate layers undergoing polishing are eliminated. As a result, the present invention provides a low cost alternative to suppliers and manufacturers of retaining rings and facilitates a method to exchange, recondition and recycle the retaining ring for an infinite period, thus reducing consumable waste materials. Further, the ring assembly maintains uniform mechanical properties and strict tolerances after post reconditioning, thus reducing the variability and maintaining process consistency.

Abstract: This data processing system for a pattern generator receives data specifying each quadrilateral element in a pattern to be generated by laser scanning or other technique. The scanning is accomplished by swaths. In the preprocessor, separate vectors are produced for the portion of each quadrilateral edge in each swath. A real time processor, including a "pipeline" or cascaded set of beam processors, is used to generate a bit map from these clipped edge vectors. The bit map itself is skew compensated to take into account relative movement between the laser scanner and the target during pattern generation.

Abstract: In this laser pattern generator, plural laser beams are arranged in a closely spaced, noninterfering array. The beams are concurrently deflected across a region of the target surface by an acousto-optic deflector driven by a swept frequency drive signal. The target is moved perpendicular to the direction of deflection to reposition it for exposure during the next stroke of the beams. The extent of target offset in the direction of deflection is measured and used to control initiation of modulation during each deflection stroke, so that each portion of the generated pattern begins from a uniform reference line on the target. Pattern data is supplied to the beam modulators in accordance with data clock pulses the repetition rate of which is established by the rate of change of frequency of the deflector drive signal.