Dresden 2011 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 25: Transport

HL 25.6: Talk

Monday, March 14, 2011, 17:15–17:30, POT 151

Thermal Probing of Heat Generation in Biased Silicon Nanowires — •Fabian Menges^1,2, Heike Riel¹, Andreas Stemmer², and Bernd Gotsmann¹ — ¹IBM Research - Zurich, 8803 Rueschlikon, Switzerland — ²ETH Zurich, 8092 Zurich, Switzerland

The limited spatial resolution of conventional thermal imaging techniques hinders the local thermophysical characterization of nanoscale electronic devices. In contrast, the demand to study heat conduction and generation in nanosystems is steadily increasing. While novel materials and device geometries tend to impede heat conduction, localized regions of increased heat generation, so-called "hot spots", limit device performance and reliability. New methods are needed to understand the manifold coupling between thermal, electrical and structural device properties. To address this issue, a vacuum-operated scanning thermal microscope was developed to allow for thermal characterization of active nanoscale electronic devices. The key element of the microscope is a microfabricated heatable silicon probe, which allows probing temperature distributions with lateral resolution below 20 nm. Self-heating of a silicon nanowire was studied in-situ as a function of applied voltages. The observed temperature distributions are governed by the ratio of heat conduction along the nanowire and heat dissipation across the nanowire-substrate interface. Furthermore, nanoscopic thermal hot spots were observed at internal junctions of a silicon nanowire diode as a function of current direction. The results are discussed in relation to nanoscale thermal management in electronic devices.