Threshold field of phase change memory materials measured using phase change bridge devices

The threshold switching effect of phase change memory devices is typically parameterized by the threshold voltage at which this breakdown occurs. Using phase change memory bridge devices of variable length, we prove unambiguously that the important parameter for threshold switching is a critical electrical field and not a threshold voltage. By switching phase change bridge devices from the amorphous-as-deposited state, we obtain threshold fields for Ge15Sb85, Ag- and In-doped Sb2Te, Ge2Sb2Te5, and 4 nm thick Sb devices of 8.1, 19, 56, and 94 V/μm, respectively.