In-plane parallel bias magnetic field generator for sputter coating magnetic materials onto substrates

摘要

Magnetic domains in a thin magnetic film on information storage devices are aligned during manufacture of the device, preferably at the time the film is deposited onto a substrate by sputtering. A compact magnetic field generator generates a parallel magnetic field across the substrate with a magnet assembly that is not larger than approximately twice the size of the substrate or not larger than the sputtering target cathode assembly. The magnet assembly includes an interior magnet with poles at opposite ends of the substrate and two side magnets having pole pieces spaced by an air gap from the poles of the interior magnet. The interior magnet preferably includes a central magnet and two intermediate magnets, which share the same pole pieces as the central magnet. The interior magnets are located between the central magnet and the side magnets. The magnets, which are preferably electromagnets, are adjusted by varying the current therethrough, preferably by adjusting the current of the intermediate magnets, or by moving the pole pieces to adjust the gaps between those of the side and interior magnets, until the field is parallel to within one degree. Magnetic devices, such as read and write heads, are produced from products of the process.