THE DESIGN AND PERFORMANCE OF PLANAR MAGNETRON SPUTTERING CATHODES

The influence of the magnetic field strength and distribution on the operation characteristics of planar magnetron has been investigated with permanent and electro-magnetic units. This electro-magnetron will give variable magnetic fields of 0. 30 mT at the center of the race track. Increasing the field up to around 35 mT (250 Gauss) gives sharp improvements in the operating characteristics and increasing the field beyond this results in only marginal improvements. The configuration of the magnetic field by pole pieces and the influence of this on the operating parameters (in particular target utilization and film impurities) has been investigated with permanent magnet systems. It is shown that suitable magnetic fields parallel to the target surface can give uniform target erosion at low operating presures with efficient line of sight and high energy transfer of material to the substrate. The design of permanent magnet units with commercially available magnets of different materials is included.