Low insertion loss RF MEMS switches fabricated on glass substrates of G2.5 size using TFT display compatible process

Abstract

This work demonstrated the first fabrication of resistive RF MEMS switches on G2.5 glass substrates via thin-film transistor (TFT) display compatible processes. By replacing gold with a copper cantilever architecture, we achieved low insertion loss ($<$0.55 dB from DC to 6 GHz) while resolving the inherent trade-off between actuation voltage and switching speed. The optimized design attained a response time of $17\mu s$ at 22 V driving voltage, with isolation exceeding 28 dB. The display process-compatible planarization and sacrificial layer techniques eliminated conventional Micro-Electro-Mechanical System (MEMS) processing while maintaining insertion loss below 0.55 dB. The successful convergence of copper-based MEMS functionality with display industry infrastructure established a transformative platform for cost-sensitive 5G applications, where traditional silicon-based approaches faced limitations in scalability and integration density.