Traceable profilometry with a 3D nanopositioning unit and zero indicating sensors in compensation method

Conventional 3D profilers suffer in their traceability and accuracy from nonlinearities of the 1D sensor (optical or tactile) and different measuring principles in the scanning plane compared to the sensor axis. These problems can be overcome using a traceable calibrated 3D positioning device combined with a probing system of negligible measuring range in compensation method. Drawback: reduced dynamics, because of the necessity of accelerated movement of the object to be measured in z-direction for compensating its varying height. Sensors with negligible measuring range to be used for this approach are an optical fixed focus sensor (SIOS GmbH, Germany) and a self-made scanning tunneling sensor without piezo scanner. The integration into the nanopositioning device is made according to a multisensor CMM with fixed and known positions of the sensors with respect to the machine coordinate system giving the possibility of using one sensor's data for navigating the other one. Main applications can be seen in measurement tasks where outstanding accuracy outrivals the need of high measurement speed, e.g. the calibration of step height and pitch standards for profilometry and also for SPM