Resistance and Threshold Switching Voltage Drift Behavior in Phase-Change Memory and Their Temperature Dependence at Microsecond Time Scales Studied Using a Micro-Thermal Stage

Kim, S., Lee, B., Asheghi, M., Hurkx, F., Reifenberg, J.P., Goodson K.E., and Wong H.S.P., 2011, "Resistance and Threshold Switching Voltage Drift Behavior in Phase-Change Memory and Their Temperature Dependence at Microsecond Time Scales Studied Using a Micro-Thermal Stage," Transactions on Electron Devices, Vol. 58, pp. 584-592.

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We study the drift behavior of RESET resistance RRESET and threshold
switching voltage Vth in phase-change memory (PCM) and their temperature
dependence. To extend the temperature-dependent measurement to
microsecond time scales, we integrate an innovative micro-thermal stage
(MTS) on the PCM cell. The MTS changes the temperature of the programmed
region of the PCM cell within a few microseconds by placing the Pt
heater in close proximity of the programmed region. First, we
experimentally verify the existing phenomenologicalRRESET and Vth drift
model for constant annealing temperature at various temperatures between
25 degrees C and 185 degrees C down to 100 mu s and show that the
measured temperature dependence of the drift coefficient agrees well
with what is expected from the existing drift models. Based on the
existing drift model for a constant annealing temperature, we derive the
analytical expression for the R(RESET) drift for time-varying annealing
temperature and experimentally verify the analytical expression. The
derived analytical expression is important to understand the impact of
thermal disturbance on PCM reliability such as variations in R(RESET)
and V(th)

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