High target utilization magnetic arrangement for a truncated conical sputtering target

• Main Author: RUSSELL DERREK ANDREW
• Format: Patent
• Language: English
• Published: 01.10.2002
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OFNEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMICBEAMS; SEMICONDUCTOR DEVICES; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

A magnetron sputter coating vacuum processing system has a magnetron cathode that includes a frusto-conical target having a cone-shaped magnet assembly that causes the erosion rate to be highest under a main magnetic tunnel at an intermediate radius or the centerline of the target when the target is uneroded, with the location of the highest erosion rate gradually shifting to two areas as the target erodes, one being an inner at radii less than that of the target centerline and one being an outer area at radii greater than the target centerline. As a result, the target erosion tends to be equalized over the target area during the life of the target, improving target utilization. The magnet assembly includes three magnet rings, including an inner ring and an outer ring having poles magnetically connected by a yoke, which rings form a main magnetic tunnel. The polar axis of the inner ring is parallel to the target surface, and the polar axis of the outer ring is perpendicular of the target surface. An intermediate magnet ring, with a polar axis parallel to the target surface and oriented to produce a field opposite to the orientation of the poles producing the main tunnel, opposes and flattens the main tunnel as the target erodes, while separate inner and outer minor tunnels supported by the magnets of the intermediate ring and the respective inner and outer rings emerge above the target surface as the target erodes and the sputtering surface recedes into the fields of the magnets.