Soft Magnetic Co-(TiN) Composite Films Realized within a Wide-Range of Cobalt Content

The effect of Co content on the magnetic properties has been systematically investigated, to obtain high frequency soft magnetic
${\rm Co}_{\rm x}-({\rm TiN})_{1-{\rm x}}$
films. The films with Co content more than 73 at.% are perpendicular magnetic, and the films with Co content less than 45 at.% are both soft and super-para magnetic. In a wide-range of Co content (
${\rm x}=45$
–73 at.%), the
${\rm Co}_{\rm x}-({\rm TiN})_{1-{\rm x}}$
nanogranular films show good soft magnetic properties, with coercivity as low as 4 Oe and magnetization around 6–12 kG. The permeability of the films is as high as about 400 and the resonance frequency is around 1 GHz. The films exhibit good thermal stability with the low coercivity of about 5 Oe even after the annealing at 500
$^{\circ}$
C, which is very important in viewpoint of application like a CMOS-compatible fabrication technology.