Advanced nanoscale metrology of pole-tip recession with AFM

Atomic force microscopes (AFM) have been widely used for precision metrology. However, most conventional AFM revealed their limits in accuracy due to the inferior characteristics of piezoelectric tube scanner. In order to overcome these limits, we introduced the new XE AFM, which has a z-scanner separated from the x–y scanner. With the new XE AFM, we were able to successfully measure dimensions of pole-tip recession (PTR) in magneto-resistance (MR) head, which had been difficult to be measured by conventional AFM. In addition, we found that it is important to use non-contact AFM, not tapping mode AFM for accurate measurement of PTR since the tapping force can depress the pole-tip region and make the PTR value appear larger than it actually is. In order to confirm this phenomenon, we performed force modulation microscopy and contact mode AFM at various force set points.