Co-Si-O素材組換えターゲットにより作製されるグラニュラー薄膜の成膜条件と構造および磁気特性

抄録

  The relationship among the sputtering conditions, composition, microstructure, and magnetic properties of Co-Si-O granular film deposited using various metal-oxide composite targets was investigated. The raw materials of the sintered targets were (a) (Co)-(SiO₂), (b) (Co)-(Si)-(Co₃O₄), and (c) (Co)-(Si)-(CoO) retaining the same nominal composition of (Co)-7.7mol%(SiO₂), Co_79.9Si_6.7O_13.4 (at%). It was found that; (1) in the case of Ar gas pressure (P_Ar) of 0.6-4.0 Pa, the discharge voltage with targets (b) and (c) was lower than that with target (a), (2) the oxygen content of the film became larger with increasing P_Ar from 0.6-8.0 Pa, (3) each granular film deposited by using the three targets with the same sputtering conditions showed nearly the same film composition, phase, microstructure and magnetic properties. This indicates that it is possible to control oxygen content and O/Si ratio in the granular film at the same time by increasing the amount of raw material of oxide in the composite target. Moreover, it is indispensable for formation of SiO₂ phase in the films to choose at least two kinds of raw materials including Si or O.