Effect of Substrate and Surface Conditioning on Magnetic Properties and Texture of CoPt Hard Bias Films

Effect of growth surface on CoPt hard bias film performance has been systematically studied using different substrates and substrate surface conditioning. Films deposited on four different types of substrates show different levels of crystallographic quality and magnetic performance. Among them, the films deposited on Al₂O₃-coated substrates are the best, up to 400 Oe higher in coercivity and 0.05 higher in remnant squareness. Proper substrate surface conditioning by ion-beam depositions has been found to be effective in improving inplace c-axis orientation; hence, magnetic properties of CoPt hard bias films. In addition, the deposition of a thin amorphous Al₂O₃ film on substrates prior to the hard bias film deposition helps to promote nearly 100% inplane c-axis crystallographic orientation.