Multidimensional Mapping of Electrical properties using Fast Force Volume

AFM-based property mapping modes such as Force Volume & PeakForce Tapping provide force spectra at each pixel enabling detailed mechanical characterization. In this work, the force spectra are augmented by also acquiring electrical spectra for every pixel of the image. During each force-distance cycle, a ‘hold segment’ is inserted during which a fixed force is applied and electrical spectra are collected by ramping certain electrical operating parameters. This results in multi-dimensional datacubes whereby electrical & mechanical spectra are present for each pixel. Optimization of the force mapping movements and the electrical measurement setup allowed us to maintain a relatively high imaging speed (typ. 20-100 ms/pixel). The approach is illustrated by four modes: In C-AFM, I-V spectra in each pixel are acquired by ramping the DC bias. The resulting datacube is used to extract high-resolution current barrier property maps. Applied to SCM and sMIM, dC/dV-V and C-V spectra are acquired. In PFM either switching loops or contact resonance spectra are obtained. Investigation of a variety of materials illustrates the capability to reveal sample properties which are not accessible or easily missed in conventional methods where maps at only one or a few discrete settings are acquired.