Demonstration of improved frequency response in laminated sputtered top poles

Summary form only given. It has been previously shown that soft, anisotropic properties can be achieved in sputtered laminated films by careful choice of lamination period and nitrogen doping level of Fe-based materials. Such films exhibit superior high frequency permeability when compared to bulk electroplated materials at sheet film level, attributed to eddy current suppression. This is an important characteristic of pole materials used in thin film recording heads under high transfer rate operating conditions. Heads have been manufactured with two-piece top poles, the upper portion of the top pole comprising of 2 /spl mu/m thick layer with a lamination period of 300 /spl Aring/ FeAlN/10 /spl Aring/ Al/sub 2/O/sub 3/. Pole definition was achieved at wafer level using conventional processing techniques. Electrical tests were performed and when the results were compared to similar heads with standard electroplated 45-55 NiFe, it was seen that the controls started to degrade at about 170-180 MHz, while heads with laminated poles did not degrade until 230-250 MHz, a 40% improvement in high frequency performance.