EFFECTS OF ROTATION AND ION INCIDENCE ANGLE ON SPUTTER DEPTH RESOLUTION IN THIN-FILMS OF NIFE/TA

In an NiFe/Ta system, interface widths (DELTA-z) are compared for sputter profiles with stationary and rotating sample holder (Zalar rotation). For low sputter angles, the Zalar rotation brings considerable improvements in DELTA-z. For higher sputter angles, the improvement available through Zalar rotation vanishes as self-shadowing due to crystallites with less favorable orientation becomes the dominating rate mechanism. The improvement is further reduced for thinner films much below 1000 angstrom. For low sputter energies and films 125 angstrom thick, Zalar rotation has no influence. The limit of depth resolution was 30 angstrom, which resulted from the substrate-induced roughness of the NiFe/Ta interface. The interface width's maximum near 31-degrees for stationary sputter etching is characteristic of sputter-deposited fcc films.