High Resolution Thermal Imaging for Electrical and Optical Characterization of Electronic and Photonic Devices.

[摘要] The impact of heating on electronic and optoelectronic devices is becoming increasingly severe as devices scale to smaller and smaller sizes. High temperature not only reduces most performance metrics, but also decreases device lifetime. In order to study and understand these problems, an important step is to measure temperature at small size scales.Here we show how CCD-based thermoreflectance temperature measurement can be successfully applied to heterojunction bipolar transistors, quantum well lasers, and quantum dot lasers for device thermal characterization with a spatial resolution of 400 nm and a temperature resolution of 10 mK. Indeed, the high spatial resolution of this technique allows one to resolve separate heat sources within a device itself; rather than viewing the entire device as a monolithic heat source, we are able to study the separate internal heat transport mechanisms that often exist.Specifically, in applying CCD-based thermoreflectance to SiGe-based heterojunction bipolar transistors, we show how temperature mapping can be used to spatially profile device current, including asymmetric behavior such as current hogging. In examining a type of high-power laser, we show how (with proper light filtering) 2D temperature profiles of the facet can be measured and linked to thermal lensing. We then describe how the CCD-based thermoreflectance setup can be modified to accommodate pulsed devices, demonstrating the technique on pulsed InGaAs quantum dot lasers and identifying separate temperature peaks due to active region heating and contact heating.Finally, we discuss how the measurement of thermal and thermoelectric properties in organic thin films can be used to derive fundamental and device-relevant electrical properties related to interface transport. By measuring the Seebeck coefficient of an OTFT, we show that one can for the first time successfully evaluate the channel thickness in a non-destructive fashion without further fabrication processes.

[发布机构] University of Michigan

[效力级别] Electronic Devices

[关键词] Thermal Imaging;Electronic Devices;Optoelectronic Devices;Mechanical Engineering;Engineering;Mechanical Engineering