Inverted field circular magnetron sputtering device
AssigneeSciVac
InventorSteven Aragon
Life of this patent
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Abstract
An inverted field circular planar magnetron sputtering device is described that produces coatings with a high degree of thickness uniformity on round wafer-like substrates. It is a compact source with no moving mechanical parts. DC signals applied to low power electromagnetic coils provide control of the coating thickness uniformity throughout the life of the target. AC signals applied to the coils oscillate the sputtering rings to improve target utilization and maintain a clean target surface. Utilization of target material is about 40% for both magnetic and non-magnetic target materials. The design accommodates versions for both direct and indirect water cooling.
Claims26
An inverted circular planer magnetron sputtering device for depositing substantially uniform coatings on substrates, comprising:
- a generally circular body having an axis of symmetry and having a target side and a back side, said target side having at least one shallow channel for flow of target coolant, said back side having formed therein a central cavity, an annular outer cavity, and an annular medial cavity disposed substantially midway between said central cavity and said outer cavity, said cavities being concentric with said axis of symmetry;
- a circular target plate having a front surface and a back surface, said target plate being affixed to said body with said back surface facing said target side;
- a plurality of permanent magnets respectively disposed within said central cavity and said outer cavity and respectively forming center and outer magnetic poles of like magnetic orientation with respect to said target plate;
- at least one annular pole piece disposed within said medial cavity;
- and
- a magnetically permeable backing plate affixed to said body and covering said back side thereof, said backing plate combining with said one annular pole piece to provide flux closure paths for an inner magnetic circuit including the permanent magnets in said central cavity and an outer magnetic circuit including the permanent magnets in said outer cavity,
- whereby when sputtering power is applied to said device, a pair of concentric plasma sputtering rings are generated including an inner sputtering ring developed by said inner magnetic circuit and an outer sputtering ring developed by said outer magnetic circuit.
Dependencies are inferred from the claim text.