Study on Preparation Method of Ultra-High-Density Magnetic Recording Media by Sputtering Using Electron Cyclotron Resonance Microwave Plasma

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To achieve ultra-high density magnetic recording, It is required that recording media have magnetic microstructure which consists of nano-meter size ferro-magnetic regions and non-magnetic regions. The purpose of this research is to establish the Co-Cr media preparation method for ultra-high density magnetic recording. In this research, a new sputtering method using electron cyclotron resonance microwave plasma (ECR sputtering) was introduced which is more suitable to control a plasma precisely than the conventional diode sputtering method.Ar ions in plasma accelerated by the voltage difference between a plasma and a substrate voltage bombared the substrate during film deposition, and make drastic influence on a creation of magnetic microstructure. Ion accelerating voltage of 20V which is a relatively low value is obtained at high Ar pocess gas pressure of 8*10^<-2>Pa and long target-to-substrate distance of 230mm. The Co-Cr media fabricated in the above mentioned sputtering condition showed good crystal orientation, high perpendicular coercivity over 1400Oe and large perpendicular magnetic anisotropy field exceeding 4kOe.To control the ion accelerating voltage in wide range, the magnetic field distribution in a deposition chamber was changed using an auxiliary coil installed near the substrate holder. At cusp magnetic field, ion accelerating voltage was decreased to 11V.The compositional separation with nano-meter size in grains which was achieved in the Co-Cr films deposited at ion accerralating voltage of 11V.From the measurement of recording characteristics, it was proved that the Co-Cr media showed ultra-high density recording resolution and low noise characteristics.