Long term thermal drift study on SPM scanners

Scanning Probe Microscopy (SPM) imaging process is inherently slow, and commonly suffers from instrumental drift. According to experience, drift is a time dependent phenomenon and therefore it influences measurement results obtained using the instruments for long periods of time, e.g. when high resolution imaging is performed by taking many profiles. Evaluation and control of actuator drift is an important issue for high accuracy measurements. In particular, a better probe positioning can be obtained through characterization of the scanning system’s metrological performance, and distinguishing systematic and stochastic behavior components. In this work, a new approach is proposed to study long term thermal phenomena, correlating them to SPM scanner drift distortions evaluated using calibrated reference samples. Long term drift evaluation is then cross-correlated to thermal analyses carried out in parallel by means of an infrared-camera. Eventually, it is discussed how the investigations here presented may be used to improve the instrument set-up in order to reduce measurement uncertainty.