TARGET ASSEMBLY FOR A MAGNETRON SPUTTERING APPARATUS, A MAGNETRON SPUTTERING APPARATUS AND A METHOD OF USING THE MAGNETRON SPUTTERING APPARATUS

摘要

To provide, in a magnetron sputtering apparatus for coating a substrate with a material of high magnetic permeability, for a sufficient trapping field of at least 24 kA/m (300 Oe) field strength above a target surface a target assembly consists of target plates (34, 33, 32) separated by through-going slits (35, 36) which the magnetic field must cross and to a support plate (31) consisting of copper to which the backside of the target is fixed. In order to avoid any release of material from the support plate and deposition of the same on the substrate each of the slits (35, 36) is shaped in such a way that there is no line-of-sight connection between the gap at the target surface and the support plate (31) at the backside of the target through the slit, the latter having, e.g., two sections which are perpendicular to the target surface, one ending at the target surface and the other at the support plate, and which are laterally offset and connected by a third section which is parallel to the target surface. Magnetic field strength in the slits (35, 36) is kept below 64 kA/m (800 Oe) to prevent the formation of plasma there.