Phase change memory (PCM) uses rapid heating and cooling to induce switching in sub-micron memory cells. The rapid rates of heating and nanoscale dimensions require accurate modeling of thermal transport phenomena in the constituent materials. This motivates improved understanding of the thermal properties of Ge2Sb2Te5 (GST) thin films and PCM electrode materials. We report measurements of thermal conductivity and interface resistance of GST and electrode materials by applying nanosecond pump-probe thermoreflectance to multilayer structures of GST-C, GST-TiN, and GST-Ti. We measure the total thermal resistance of the stack from the transient thermal response, separating the intrinsic and boundary resistance terms using a 1-D resistor model of the stack. The intrinsic conductivities for GST are 0.20 W/(m K) for GST-C, 0.33 W/(m K) for GST-TiN, 0.27 W/(m K) for low temperature deposited GST-Ti, and 0.69 for high temperature deposited GST-Ti. The thermal boundary resistances are 27.5 m(2)K/GW for GST-C, 5.2 m(2)K/GW for GST-TiN, 49.8 m(2)K/GW for low temperature GST-Ti, and 11.4 m(2)K/GW for high temperature GST-Ti.

Owing to their extraordinarily high thermal conductivities, carbon nanotubes (CNTs) are promising for use in advanced thermal interface materials (TIMs). While there has been much previous research on carbon nanotube thermal properties, there are little data for aligned films of single wall nanotubes. This paper measures the thermal interface resistances of metal-coated vertically-aligned single wall CNT (SWNT) arrays using a nanosecond pump/probe thermoreflectance technique. The data capture the vertical variation of CNT thermal properties including their interface resistances. The data show the total thermal resistance of the TIM is R" swnt,tot =1.2 times 10 -5 m 2 KW -1 , and that the CNT-metal interface resistance strongly reduces the effective vertical thermal conductivity. An approximate model shows that the evaporated metal film contacts only a small fraction of the CNTs. Based on the conclusions of the model, the individual CNT-metal contact conductance is h cnt-metal,a =6.6 times 10 7 Wm -2 K -1 which is quite good. Increasing the number of CNT-substrate contacts is a very promising approach for improving the thermal performance of CNT-based interface materials

Thermal phenomena are having an increasing influence on drive and leakage currents in modern transistors. This trend is accelerated for confined-geometry devices, which include thermally-resistive interfaces and materials with low thermal conductivity (e.g. SiO2, Si 1-xGex). This paper summarizes the nanotransistor thermal design challenges and reviews the latest advancements in electro-thermal modeling

Thermal simulations are important for advanced electronic systems at multiple length scales. A major challenge involves electrothermal phenomena within nanoscale transistors, which exhibit nearly ballistic transport both for electrons and phonons. The thermal device behavior can influence both the mobility and the leakage currents. We discuss recent advances in modeling coupled electron-phonon transport in future nanoscale transistors. The solution techniques involve solving the Boltzmann transport equation (BTE) for both electrons and phonons. We present a practical method for coupling an electron Monte Carlo simulation with an analytic split-flux form of the phonon BTE. We use this approach to model self-heating in a 20 nm quasi-ballistic n+/n/n+ silicon diode, and to investigate the role of hot electron and hot phonon transport.