Development of mjtcs on fused silica substrates at nist

We are developing a new generation of thin-film multijunction thermal converters based on fused silica substrates for ac voltage measurements at frequencies up to 100 MHz and for ac current measurements at frequencies up to 1 MHz. Fused silica has been selected over the previous crystalline quartz material because it is significantly more robust that crystalline quartz, yet retains excellent dielectric properties. We report on the design and fabrication of the new fused silica chips, including a novel method for forming thin membranes, and present results for two designs as both ac voltage and current converters.