[4C4] Microwave resonator method for characterising electrical properties of thin films and other advanced materials
L Hao, J Gallop, J Williams and O Shaforost
National Physical Laboratory, UK
At the National Physical Laboratory (NPL) a method has been invented and patented for characterising electrical properties of advanced materials such as thin films, graphene and semiconductor thin film. The technique is based on perturbation of a microwave dielectric resonator. The method is non‐invasive and fast. Being non‐invasive means that the conductivity of the graphene/thin film sample can be measured without touching it (normal methods require either patterning the thin film or contacting it with probes and both of these have to be carried out offline). The technology is fast, with a single measurement taking a fraction of a second, so the quality of the material can be monitored as it flows off the production line, even at a rate of metres/minute, in principle. The microwave dielectric resonator system is self‐contained and is potentially usable in relatively harsh environments.
In addition, as well as conventional electrical sheet resistance measurements, a version capable of electrical mobility and charge carrier concentration is under development.
In addition, as well as conventional electrical sheet resistance measurements, a version capable of electrical mobility and charge carrier concentration is under development.
