Characterization of Heat Propagation along Single Tin Dioxide Nanobelt Using the Thermoreflectance Method

Abstract

In this paper, we studied heat transfer properties of a single tin dioxide nanobelt using non-contact high resolution thermoreflectance imaging technique. Temperature difference across the nanobelt was created by attaching its both ends to a microfabricated thin film heater and sensor pair. High resolution thermal images of the nanobelt and thin film devices were obtained at variant pulsing current amplitudes and frequencies, which allowed us to study the inherent thermal conductance of the nanobelt. Thermoreflectance coefficient change was found to significantly affect the thermoreflectance measurement results. INTRODUCTIONOne-dimensional nanostructures such as nanowires and nanobelts have been studied extensively during the past few years. Compared to bulk materials, in low dimensional inorganic nanostructures, quantum effects and high surface to volume ratio become important. The modified density of electronic states and increased surface scattering, etc, can alter the bulk properties substantially. These significant differences promise one-dimensional nanostructures important applications in the emerging nano-electronic and nano-optical industry. Among all functional nanostructures, the ribbon-or belt-like metal oxide, such as tin dioxide (SnO 2 ), zinc oxide (ZnO 2 ) and Indium oxide (In 2 O 3 ) nanostructures are unique due to the reason that they are essentially single-crystalline semiconductors without the presence of a surface insulating layer of native oxides [1].Thermal transport property is one of the key factors limiting the performance and reliability of all nano-electronic and nano-optoelectronic devices. Metal oxide nanobelts or nanoribbons provide interesting systems for studying heat propagation behavior in low dimension. However, measurement of thermal properties on such small objects is non-trivial. As of today, only a few thermal characterization techniques are able to achieve nanoscale spatial resolution and sub-degree temperature resolution at the same time [2]. Here, we utilized thermoreflectance imaging technique. It is a non-contact temperature measurement technique that eliminates the thermal leakage error accompanied by making thermal contact. We have obtained thermal profiles along a single tin dioxide (SnO 2 ) nanobelt with various bias currents amplitudes and frequencies applied to the attached micro device.

Bias-dependent MOS transistor thermal resistance and non-uniform self-heating temperature

“…Since the dependence of the reflectivity on the local temperature variation is very small, the lock-in technique is typically utilized when the device is cycled [5,6]. As the hardware based lock-in is prohibitive for high spatial resolution full-field image detection, where hundreds of channels are carrying signals in parallel, we used the software based lock-in in our thermoreflectance imaging system.…”

“…Non-contact thermoreflectance imaging is capable of obtaining thermal images with both high spatial resolution (sub-micrometres) and temperature resolution (sub-kelvin) [5,6]. It has recently been utilized to characterize the heating effects in metallic oxide semiconductor transistors [7].…”

Temperature nonuniformity and bias-dependent thermal resistance in multi-finger MOS transistors

“…This small change in 10 -4~1 0 -5 range per degree is typically detected using lock-in technique when the temperature of the device is cycled [3,4]. Images are detected by either a PIN diode array camera or a high frame rate Intensified CCD (ICCD).…”

“…Non-contact thermoreflectance imaging is capable to obtain thermal images with both high spatial resolution (submicron) and temperature resolution (sub-Kelvin) [3,4]. It has recently been utilized to characterize heating effects in MOS transistors [5].…”