Resistance Ratio Enhancement in Phase-Change RF Switches at Cryogenic Temperatures

This letter reports the dc and radio frequency (RF) performance of the phase-change RF switches (PCRS) as a function of temperature. Resistance change behavior of the germanium telluride (GeTe) material is experimentally investigated over 77 to 335 K. The device shows metallic behavior in the crystalline state which exhibits consistent low resistivity over a wide temperature range, while in the amorphous state, resistance increases to more than eleven orders of magnitude as a function of decreasing temperature from 300 to 77 K. Device current–voltage (IV) characteristics and the RF performance are investigated for multiple device cycles. The RF performance of the PCRS is reported with and without microheater are examined to confirm the performance variation of the phase-change switches at cryogenic temperatures.