This paper presents the phase change characterization of Germanium Telluride GeTe used for RF switches when a direct heating is performed. The study describes the method to activate the transition between crystalline and amorphous states, allowing to reach a resistance ratio of 1.8.10 4 between both states. RF measurements were performed up to 40 GHz on fabricated switches, showing an ON-state resistance of 1.7 Ω. An OFF-state capacitance of 5.4 fF was extracted from simulation, resulting in an estimated cutoff frequency of 17 THz. The study also shows the importance of the GeTe thickness to optimize the performance of the device.

* 2xW in shunt **see definition in section III, equation (2) **estimated (as twice that in series configuration as is almost doubled)

This paper presents a RF to mm-wave switch based on Germanium Telluride phase change material. An integration process compatible with a standard CMOS back end of line is proposed to realize directly heated switches. RF measurements, performed up to 65 GHz, show an ON-state resistance of 1 Ω with an OFF-state capacitance of 7 fF corresponding to a 22 THz cutoff frequency which constitutes a state-of-the-art Figure-of-Merit. Switching time of only 60 ns in both phase changes allow energy consumption one decade lower than the state-of-the-art for crystallization. A geometrical variation of GeTe dimensions shows a linear evolution of RF performance in terms of ON-state resistance and an almost unchanged performance in the OFF-state.