We report on the first SbTe phase-change material RF switches with a refractory TiW heater in a planar configuration. With the planar layout and heater reliability, a record switching cycle endurance of >300K was demonstrated. With on-state resistance of 0.5 ohm∗mm and off-state capacitance of 75 fF/mm, the RF switch figure-of-merit (FOM) is 4.1 THz, which is 6–7 times better than state-of-the-art RF switches, including RF silicon-on-insulator technology. With further layout optimization, SbTe phase-change material RF switches could be a potential candidate for future RF switch technology.