Extremely clean sputtering process and microstructural properties of Ni-Fe films fabricated by this process

A specialized sputtering machine which enables the film deposition in the extremely clean atmosphere (XC-process) was newly constructed. Excellent base pressure less than 8×10−12 Torr, which corresponds to about 1×10−8 Torr l/sec in the build up rate, succeed in realization in the process chamber. By use of both this new sputtering chamber and highly purified Ar gas with large amount of flow rate, the very low impurity level during deposition is realized in the XC-process. This impurity level is about 4 orders lower than that of the normal sputtering process. By applying the XC-process to the fabrication of Ni-Fe films, grain size remarkably increases, and the highly coherent (111) crystal plane with lower fault density forms continuously from initial layer to the top of the films.