1305.4946 (Kyle L. Grosse et al.)

Direct observation of nanometer-scale Joule and Peltier effects in phase
change memory devices    [PDF]

Kyle L. Grosse, Feng Xiong, Sungduk Hong, William P. King, Eric Pop

We measure power dissipation in phase change memory (PCM) devices by scanning Joule ex-pansion microscopy (SJEM) with ~50 nm spatial and 0.2 K temperature resolution. The temperature rise in the Ge2Sb2Te5 (GST) is dominated by Joule heating, but at the GST-TiW contacts it is a combination of Peltier and current crowding effects. Comparison of SJEM and electrical characterization with simulations of the PCM devices uncovers a thermopower ~350 uV/K for 25 nm thick films of face centered-cubic crystallized GST, and contact resistance ~2.0 x 10^-8 Ohm-m2. Knowledge of such nanoscale Joule, Peltier, and current crowding effects is essential for energy-efficient design of future PCM technology.

View original: http://arxiv.org/abs/1305.4946