Advanced Materials Design by Lithography Technique

Abstract

Magnetic materials have been known from at least bc seventh century. The oldest magnetic materials are thought to be magnetite. The word of “magnet” is thought to come from the name of the Magnesia district in ancient Greece. A lot of magnetite was produced in the Magnesia district. The magnetic materials have been applied to compass for voyages from fourteenth century in Europe. The scientific investigation on magnetism has started from sixteenth century. As mentioned above, the magnetic materials have a very long history. In modern world, the magnetic materials are widely applied to the permanent magnets, magnetic sensors, transformers, medical equipments, and so on. From the 1990s, the magnetic materials have been used for spin-electronics devices. The first application of the spin-electronics devices was the magnetic heads (Tsang et al., IEEE Trans Magn 30:3801–3806, 1994; Heim et al., IEEE Trans Magn 30:316–321, 1994) in hard disk drives. Recently, the spin-electronics devices have been widely investigated (Rippard et al., Phys Rev Lett 92:27201, 2004; Tulapurkar et al., Nature 438:339–342, 2005). In this chapter, magnetic memories, magnetic logic devices and lithography techniques that are utilized to fabricate the small spin-electronics devices are introduced.