Fabrication and Magnetic Properties of Thin Films Sputtered on the Substrate Excited by SAW

Permalloy films of thickness 300 Å were deposited by d.c. magnetron sputtering onto LiNbO3 single-crystal substrates excited by SAW (surface acoustic waves) at 45 MHz. Film structures, such as grain shapes and sizes were found to change drastically as functions of the excitation amplitude. Particularly when deposited at an excitation amplitude of 24 ÅQ-p, films consisted of very fine homogeneous grains and showed soft magnetic properties, namely a minimum coercive force. A uniaxial anisotropy was induced in the film plane in all films examined; however, at the critical amplitude, the in-plane easy axis was found to change significantly. It was concluded that deposition of film onto substrates excited by SAW is a highly useful method for controlling the film microstructure and magnetic properties.