What are “thin films” and what are “thick films”?
Microwave components are currently being made using high-temperature superconductors in two distinct ways. Thin-film technology can be used to make planar circuits for microwave applications, including filters, resonators, delay lines and others. In order for these devices to work well, the superconducting material must be of very high crystalline quality. An alternative approach is to take copper microwave components, such as resonant cavity filters, and coat them with a paste of superconductor precursor material that is then fired on to form a ceramic superconducting coating. The crystalline quality of the resultant material is poor, but there is enough of it to provide the low-loss benefits of superconductors anyway. One disadvantage of this technique is that the resultant electronic components are not much more compact than their conventional counterparts. Another is that it is only applicable to certain applications where a superconducting coating will be beneficial.
