The accurate measurement of local RF-voltages within integrated circuits is crucial for the development of miniaturized electronic devices. Contactless probing techniques are considered a promising approach to overcome the space limitations imposed by the size of required contact pads used in conventional probing techniques. This project aims at developing a scanning probe based measurement system capable of mapping voltages within RF-devices with sub-um spatial resolution.
Scanning probe based microscopy systems are widely used for surface analysis in various research fields, such as biology, physics and material science. A small probe is scanned over the investigated sample to record surface properties with nanometer resolution. Due to its outstanding spatial resolution, this concept is employed for the measurement of voltages in highly integrated RF-devices in this project.
A small conducting probe is used as capacitively coupled sensor which is moved to individual circuit test points using high precision positioning stages. The measurement system can therefore be used for contactless evaluation of circuits without modifications of the layout. The small physical size of today’s RF-devices impose major challenges on the development of the system which have to be solved and will be addressed in this project.
To this end, a detailed analysis of the probe-circuit interaction is carried out using electrostatic and circuit simulations to identify the relevant trade-offs between sensitivity, spatial resolution and invasiveness, thus enabling the selection of suitable measurement parameters for achieving the best possible performance.