Structural characteristics of bias sputtered CoCrTa/Cr films

Crystallographic texture and lattice spacings of bias sputtered CoCrTa/Cr and Co/Cr thin films have been studied by X-ray diffraction. While only an insignificant change in the Co lattice spacing for the Co/Cr films was observed as the substrate bias voltage was increased, the increase in the CoCrTa lattice spacing for the CoCrTa/Cr films was substantial. The CoCrTa films showed nearly unchanged lattice spacings after a vacuum annealing for film stress release. The lattice increase appeared to be linearly proportional to the Ta content in the CoCrTa film. This implies that the Ta atoms tend to substitute randomly onto the hexagonal sites within the CoCrTa crystal grains, and that very little, if any of the Ta segregates to the grain boundaries