Submicron Device Level Thermal Characterization for Photonics and Power Devices

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Infrared (IR) Thermography has been widely used as a tool for thermal mapping and characterization of devices and systems. This technique conveniently provides non-contact measurement and the resulting 2-D thermal map provides a global view of the thermal characteristics of the target device. However, there are some major limitations with this technique in terms of spatial and temporal resolution, especially for photonic or high power device applications. The thermoreflectance thermal imaging provides a solution that addresses these challenges. We will demonstrate this capability with examples and provide the scientific background for this imaging technique. The equipment is commercially available with visible light optics, a CCD image sensor, and with sophisticated user-friendly software and the applicable signal control electronics. In contrast to typical InGaAs or InSb sensor array for IR Thermography, the visible CCD sensors are mass produced and can provide a greater number of pixels. Microsanj demonstrated how the  Thermoreflectance Imaging Analyzer can be used to detect static and dynamic hot spots on a sub-micron scale with a temperature resolution of 0.1 °C and a time resolution of 800 picoseconds. Key Highlights:

• Introduction to microscale and nano-scale thermal characterization techniques

• Basic principles of thermoreflectance imaging

• Determination of the thermoreflectance coefficient and its material and wavelength sensitivity

• Thermal imaging results for high power silicon and GaN transistors, electro-static-discharge protection devices, solar cells, and light emitting diodes.

• Through-the-substrate infrared illumination for thermal analysis of devices in flip-chip packages

• Thermal characterization of micro-refrigerators employing super lattice thin films, which have been demonstrated to provide localized cooling of 680 W/cm2.

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