AFM tip gauge by nuclear tracks methodology

Abstract

Atomic force microscopy (AFM) instrumentation in the different modes of operation is a metrologic system for evaluating some surface properties of solid and semisolid materials. The resolution of this instrument depends strongly on the tip sharpness, which can be changed by contamination of the AFM tip apex due to wearing and/or breaking. In order to assess new and old tips, scanning electron microscopy (SEM) inspection is often used, which is not very convenient due to the availability and demand of SEM services. In the market there are some expensive devices for verification of the tip geometry, and for the particular case of AFM in the tapping mode, a simple proposal has been published based on fiber-like samples. In this work, we present an AFM tip gauge device based on the use of a pattern of etched tracks on CR-39 material. For the preparation of the device, the requirements are a radioactive alpha particle source with specific energy, controlled temperature bath and KOH solution, with all these parameters optimized for the tip evaluation, based on the AFM profilometry image. This work shows another interesting and a very useful application of nuclear tracks methodology (NTM).