High resistivity FeXN sputtered films for magnetic storage devices and method of fabrication

Abstract

A preferred method of the present invention provides an improved thin film for carrying magnetic flux. With the preferred method, the magnetic thin film may be formed by depositing Fe by reactive sputtering using N2 to form a thin film comprising α-Fe and γ-Fe4N. With this method, the relative percentage of γ-Fe4N in the deposited film is increased to provide expanding lattice constants for both the α-Fe and the γ-Fe4N. Increasing γ-Fe4N increases resistivity while expanding lattice constants to provide improved coercivity at higher resistivity. Increasing the percentage of γ-Fe4N to provide expanding lattice constants for both the α-Fe and the γ-Fe4N may be accomplished by adjusting sputtering power, N2 gas percentage, a flow rate of N2, and substrate bias. In some embodiments, high sputtering power of about 3-4 kW with about 15-30 percent of N2 may be used to sputter FeX, where X is selected from the group consisting of Rh, Ta, Hf, Al, Zr, Ti, Ru, Si, Cr, V, Si, Sr, Nb, Mo, Ru, and Pd, to provide expanding α-Fe and γ-Fe2N lattice constants. In some embodiments, FeXN films having resistivity values greater than about 50 μΩcm, 80 μΩcm, 100 μΩcm, 115 μΩcm, or more, for coercivity values less than about 10 Oe, 5 Oe, or 3 Oe are possible, for values of Bs greater than around 12 kG to 17 kG. Embodiments may be used for pole or shield structures in magnetic heads for data storage and retrieval apparatuses to improve high frequency performance.

Dependencies are inferred from the claim text.