Fabrication of nanomagnetic probes via focused ion beam etching and deposition

A focused ion beam (FIB) process can be utilized not only for etching but also for deposition at dimensions in the nanoscale range. In this paper, a ring-type magnetic head with dimensions in the nanoscale range was fabricated via FIB etching followed by FIB deposition of non-magnetic tungsten into the etched trenches. As a result, magnetic pole tips each with a cross-section as narrow as 140 × 60 nm2 and with a length as tall as 500 nm were protected and supported from all the sides. Direct observation of the 'easy' magnetization switching via magnetic force microscopy verified that favourable magnetic properties were preserved during such nanoscale processing.