Integrated MEMS RF Probe for SEM Station—Pad Size and Parasitic Capacitance Reduction

Abstract

This letter describes a new generation of instrumentation that aims to address both on-wafer measurement of nano-devices in the microwave regime and reduction of probing pads parasitic effects. The system consists of a scanning electron microscope equipped with XYZ nano-positioners and in-house MEMS-based miniaturized ground-signal-ground probes able to probe drastically reduced access pad (2 $\,\times\,$ 2 $\mu$ m $^{2}$ ). The proof-of-concept of this system is demonstrated through one-port calibrated $S$ -parameter measurements up to 4 GHz. Comparison with a conventional on-wafer set-up shows a reduction of parasitic capacitance of the probing pad by one order of magnitude. Pad capacitances as low as 200 aF are measured.