Effects of substrate temperature on the magnetic properties of as-sputtered FeTaN films

We investigated the magnetic properties of as-sputtered FeTaN films as a function of deposition temperature and composition. At the deposition temperature higher than 200°C, both soft magnetism and magnetic moments can be fully achieved. While the Ta and N contents in the films affect the magnetic properties, the N content exhibits stronger effects. The magnetic properties are affected by the film microstructures via, crystallinity, grain size, and formation of Fe_xN phases. An excessive N incorporation into the films causes incomplete crystallization and/or formation of Fe₃N phases in the as-deposited state, leading to a poor soft magnetic property. As-deposited FeTaN film at the optimum composition of Fe_91.7Ta_4.2N_4.1 gives the best soft magnetic properties; coercivity of ~₂ Oe and permeability of ~1600 stable up to the frequency of 100 MHz