Measurement uncertainty in nanometrology: leveraging attributes of TEM and CD AFM

A new method is presented to accurately determine the exact location of a transmission electron microscopy (TEM) sample extraction site using critical dimension atomic force microscopy (CD AFM). The method entails use of the CD AFM to non-destructively pre-screen the sample, thus acquiring a "fingerprint" of the surface morphology in the region of interest. Following TEM sample "milling" and extraction, the acquired TEM micrograph feature measurements are matched to their CD AFM counterparts. By acquiring multiple feature profiles within the same TEM sample, the matching and "unique" TEM sample location is determined independently of scaling variation between the TEM and CD AFM metrologies. This method is then used to validate CD AFM image reconstruction algorithms in the present paper.