Preparation of TbFeCo Films by Two Source Magnetron-Sputtering

Abstract

An investigation was made to evaluate the variation in the magnetic and magneto-optic properties of amorphous TbFeCo alloy films deposited by the two source magnetron-sputtering method as a function of sputtering parameters, such as rf input power, Ar pressure and substrate rotation.
With the variation of Ar pressure, saturation magnetization (M_s), coercivity (H_c) and deposition rate of amorphous TbFeCo alloy films changed. Ms reached the minimum value, although H_c and the deposition rate reached the maximum value at about 5mTorr Ar. Using mass spectrometry to detect the ionic species in the glow discharge plasma, we found that the ion current for ionic species, such as Ar⁺, Fe⁺, Co⁺ and Tb⁺, had the maximum value at about 5 mTorr Ar. These results indicate that the changes in the magnitude of M_s, H_c and deposition rate are due to the changes in sputtered atomic number.
With the variation of substrate rotation, M_s, the perpendicular magnetic anisotropy energy (K_⊥) and the Kerr rotation angle (θ_k) did not change above about 20 rpm but increased rapidly below this. This seems to be due to the changes of composition and structure in the micro area of the film; however, these were not detected by energy dispersive X-ray fluorescence analysis, Auger electron spectroscopy or reflection electron diffraction.