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 (F_co) of 12.5 THz. This represents the highest reported Fco achieved with chalcogenide switches to date. The threshold voltage (V_th) 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.