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 microinductors, the magnetic and structural properties of highly resistive Fe-BN films were observed. In the case of the films deposited on substrates electrically isolated from a chamber, Bs, resistivity, and Hc varied as functions of the sputtering gas pressure (Ps). The structures of as-deposited films were amorphous, and on annealing they crystallized into an α-Fe single phase. On the other hand, the above parameters were independent of Ps for films deposited with a negative bias voltage applied to their substrates. These films were also in anamorphous as-deposited state, and crystallized into Fe3B and α-Fe on annealing. XPS analysis revealed that application of a negative bias voltage decreased the N and O content, especially the concentration of BN, in these films. This finding is attributed to the enhancement of Ar+ ion bombardment at the time of deposition.