Relationship between Deposition Conditions and the Magnetic Properties of Highly Resistive Fe-BN Films

In an effort to obtain a high-quality magnetic thin film for use in micro-inductors, the magnetic and structural properties of highly resistive Fe-BN films were studied. In the case of films deposited on substrates electrically isolated from ground, the Bs value, resistivity, and Hc all varied as functions of the sputtering gas pressure (Ps). The structures of as-deposited films were amorphous, and on annealing they crystallized into an ¿-Fe single phase. On the other hand, the above parameters were independent of Ps for films deposited with a negative bias voltage applied to the substrate. These films were also amorphous in the as-deposited state, and crystallized into Fe3B and ¿-Fe on annealing. XPS analyses revealed that application of a negative bias voltage decreased the N and O contents, and especially the concentration of BN, in these films. This finding is attributed to the enhancement of Ar⁺ ion bombardment at the time of deposition.