抄録
Mn-Zn spinel ferrite thin films were prepared on a Pt underlayer by reactive facing-targets sputtering to increase the deposition rate to improve the productivity. The film prepared at PO2 of 25% crystallized and possessed 4πMs of 3.4 kG. The discharge voltage changed with PO2 because of the oxidation of the target surface. The discharge voltage-current characteristics were examined to clarify the extent of oxidation of the targets. It was found that a proper discharge voltage is required to prepare Mn-Zn ferrite films. Although saturation magnetization increased with increase in substrate temperature, the surface roughness also increased. By thinning the Mn-Zn ferrite films and inserting the hyperoxidized layer that showed flat surface as the interlayer, the surface roughness of the film decreased from 4.4 nm to 2.8 run. Saturation magnetization was improved from 3.4 kG to 4.8 kG in the same preparation condition (Ts=400°C, PO2=25%) by adjusting the inlet position of O2 gas. By using the new method, the deposition rate increased to be 16 times that of the conventional method.
