12.5 THz Fco GeTe Inline Phase-Change Switch Technology for Reconfigurable RF and Switching Applications

Improvements to the GeTe inline phase-change switch (IPCS) technology have resulted in a record-performing radio-frequency (RF) switch. An ON-state resistance of 0.9 Ω (0.027 Ω·mm) with an OFF-state capacitance and resistance of 14.1 fF and 30 kΩ, respectively, were measured, resulting in a calculated switch cutoff frequency (Fco) of 12.5 THz. This represents the highest reported Fco achieved with chalcogenide switches to date. The threshold voltage (Vth) for these devices was measured at 3V and the measured third-order intercept point (TOI) was 72 dBm. Single-pole, single-throw (SPST) switches were fabricated, with a measured insertion loss less than 0.15 dB in the ON-state, and 15dB isolation in the OFF-state at 18 GHz. Single-pole, double-throw (SPDT) switches were fabricated using a complete backside process with through-substrate vias, with a measured insertion loss 0.25 dB, and 35dB isolation.