Surface roughness of microfabrication and its influence on integrated interconnect transmission loss

Here, the disparity in metal surface roughness and its impact on loss is investigated for the integrated interconnection of optoelectronic devices fabricated by wafer-level multilayer metal-air-dielectric additive-manufacturing technology. The metal surface roughness and its influence on integrated interconnect transmission loss was analyzed. According to the different contact materials and post-treatment technique, a variety of metal surface models were established. The metal surface roughness of the fabricated samples was measured, and the influence of the micro-machining process was verified. Meanwhile, micro-coaxial transmission lines are employed as the research object to validate the mechanism of surface roughness affecting transmission loss. The measured results of the transmission line samples are well consistent with the finite element simulation results by considering the actual metal roughness.