Abstract
Reactive sputtering apparatus utilizing electron cyclotron resonance (ECR) microwave plasma was developed for deposition of ferrite thin-films. High deposition rate of 44 nm/min. was achieved using a conic alloy target, and the deposited soft ferrite thin films successfully crystallized without heat treatment during film deposition and post annealing. Magnetic and physical properties for the films were analyzed in terms of saturation magnetization, coercivity, uniformity of film thickness, and inner stress. These properties were proved to be good enough as soft magnetic films. The result described that the oxygen partial pressure ratio to deposition rate strongly affected the magnetic properties. Well crystallized ultra thin (3-nm-thick) ferrite films were also successfully deposited on MgO(100) underlayer. These results imply that ECR sputtering method is one of the most effective deposition methods for highly crystallized polycrystalline thick and thin films. Low target voltage sputtering as low as −100 V successfully improved crystal orientation of the ferrite films by suppressing the affect of recoiled argon ion bombardment to the substrate.
