Properties and structure of AlSiN and AlSiON films

Magneto-optical disks employ rare earth-transition metal amorphous alloy films (RE-TM films) as recording films, therefore improvement of the corrosion resistance of such disks is an important problem which must be resolved to enable practical application. Development of protective layers for magneto-optical disks is important to improving corrosion resistance. Such protective layers must offer excellent protective performance, and must also have a large refractive index in order that a large Kerr effect enhancement be obtained. AlSiN and AlSiON films are being developed for use as protective films meeting these requirements. However, as yet not much is known about the structure, bonding states, and relation between composition and refractive index of such films. This article reports on the refractive indices, structures, and bonding states of AlSiN and AlSiON sputtered films.