Arrays of GeTe electrically activated RF switches

We report the fabrication and the high-frequency characterization of four-terminals GeTe-phase change material RF switches. The device integrates an indirect heating system for reversible changing the GeTe material's state from crystalline to amorphous. We show that the dimensions of the GeTe patterns have to be optimized for obtaining high on-state resistances of a single device and proper RF performances. For an electrical activation of an initially crystalline GeTe pattern to its amorphous state we used an electrical pulse with a 500 ns duration and 60 mA intensity resulting in switches having 7fF off-state capacitance. The reverse process (switch turned to the ON state) requires an electrical pulse of 3 ps and 40 mA intensity, resulting in an on-state resistance of 36Ω. We demonstrate that arrays of similar 8-switches present very good performances, with 0.8 dB of insertion loss and 25 dB of isolation at 5 GHz.