Nondestructive imaging of the microwave properties of superconducting thinfilm devices with a scanning microwave near-field microscope

In this paper, nondestructive microwave scanning techniques have been used to image the local microwave properties of planar microwave devices. A coax ial cavity, together with a niobium tip, has been used as a probe in the sc anning microwave near-field microscope. Quantitative images of the dielectr ic constant of the substrates as well as the variations of the surface resi stance of the line patterns in the metal multilayers have been obtained. Lo cal surface resistances at 3GHz have been measured on microwave devices pre pared with laser ablated YBaCuO thin films, which helps in evaluating the p erformance of the devices.