In-situ internal stress observation of ferromagnetic thin films at the initial stage of the film growth during sputter-deposition process

Facing targets sputtering (FTS) system (Fig. 1(a)) can form various functional ferromagnetic thin films owing to its unique sample and targets configuration. Ru/FeCo(B) thin films prepared by the FTS system shows large uniaxial magnetic anisotropy along the facing targets direction in the film plane.[1] Structural analysis using in-plane X-ray diffraction measurements clarified that the in-plane anisotropy was caused by an anisotropic residual stress formed during deposition process. However, the origin of the anisotropic residual stress has not been understood yet. Since the initiation and accumulation of the residual stress during the film formation seem to be important; we developed high sensitive in-situ internal stress observation system to clarify the initial stage of the film growth. In this study, we discuss the film formation process at the initial stage of various ferromagnetic and non-magnetic films formed by FTS system using in-situ observation results.