In-depth caracterisation of the structural phase change of Germanium Telluride for RF switches

International audienceThis 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