@inproceedings{harris_pavlidis_wyers_newberry_graham_franzon_davis_2016, title={Thermal raman and IR measurement of heterogeneous integration stacks}, DOI={10.1109/ITHERM.2016.7517727}, abstractNote={Thermal management and planning is important for heterogeneous integration due to the introduction of a complex thermal path. Thermal measurement of operating devices provides necessary data points for future design as well as validation of models. In this paper, two methods for measuring thermal performance of DAHI (Diverse Accessible Heterogeneous Integration) GaN HEMTs are presented and contrasted: IR microscopy and micro Raman spectroscopy. The QFI IR system uses a per-pixel material emissivity flat temperature calibration when the device is in an off-state, and then calculates operating temperatures by CCD exposure. Two separate QFI systems with differing CCD resolutions were used to collect thermal data and are compared. Raman Thermometry by contrast, is a laser point measurement of the frequency shift in scattered photons due to phonon vibrational modes whose frequencies are temperature dependent. Differences in measurements between the two methods arising from the stack of materials used in the DAHI process and their transparency are discussed. A method for measuring the surface temperature of the devices through Raman by the use of TiO2 nanoparticles is also presented in conjunction with a profile of the HEMT. Measurements are presented alongside thermal simulation results using prototype software Mentor Graphics™ Calibre®.}, booktitle={2016 15th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)}, author={Harris, T. R. and Pavlidis, G. and Wyers, E. J. and Newberry, D. M. and Graham, S. and Franzon, P. and Davis, W. R.}, year={2016}, pages={1505–1510} }
 @article{harris_priyadarshi_melamed_ortega_manohar_dooley_kriplani_davis_franzon_steer_et al._2012, title={A Transient Electrothermal Analysis of Three-Dimensional Integrated Circuits}, volume={2}, ISSN={["2156-3985"]}, DOI={10.1109/tcpmt.2011.2178414}, abstractNote={A transient electrothermal simulation of a 3-D integrated circuit (3DIC) is reported that uses dynamic modeling of the thermal network and hierarchical electrothermal simulation. This is a practical alternative to full transistor electrothermal simulations that are computationally prohibitive. Simulations are compared to measurements for a token-generating asynchronous 3DIC clocking at a maximum frequency of 1 GHz. The electrical network is based on computationally efficient electrothermal macromodels of standard and custom cells. These are linked in a physically consistent manner with a detailed thermal network extracted from an OpenAccess layout file. Coupled with model-order reduction techniques, hierarchical dynamic electrothermal simulation of large 3DICs is shown to be tractable, yielding spatial and temporal selected transistor-level thermal profiles.}, number={4}, journal={IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY}, author={Harris, T.R. and Priyadarshi, S. and Melamed, S. and Ortega, C. and Manohar, R. and Dooley, S.R. and Kriplani, N.M. and Davis, W.R. and Franzon, Paul and Steer, M.B. and et al.}, year={2012}, month={Apr}, pages={660–667} }
 @article{melamed_thorolfsson_harris_priyadarshi_franzon_steer_davis_2012, title={Junction-level thermal analysis of 3-D integrated circuits using high definition power blurring}, volume={31}, DOI={10.1109/tcad.2011.2180384}, abstractNote={The degraded thermal path of 3-D integrated circuits (3DICs) makes thermal analysis at the chip-scale an essential part of the design process. Performing an appropriate thermal analysis on such circuits requires a model with junction-level fidelity; however, the computational burden imposed by such a model is tremendous. In this paper, we present enhancements to two thermal modeling techniques for integrated circuits to make them applicable to 3DICs. First, we present a resistive mesh-based approach that improves on the fidelity of prior approaches by constructing a thermal model of the full structure of 3DICs, including the interconnect. Second, we introduce a method for dividing the thermal response caused by a heat load into a high fidelity “near response” and a lower fidelity “far response” in order to implement Power Blurring high definition (HD), a hierarchical thermal simulation approach based on Power Blurring that incorporates the resistive mesh-based models and allows for junction-level accuracy at the full-chip scale. The Power Blurring HD technique yields approximately three orders of magnitude of improvement in memory usage and up to six orders of magnitude of improvement in runtime for a three-tier synthetic aperture radar circuit, as compared to using a full-chip junction-scale resistive mesh-based model. Finally, measurement results are presented showing that Power Blurring high definition (HD) accurately determines the shape of the thermal profile of the 3DIC surface after a correction factor is added to adjust for a discrepancy in the absolute temperature values.}, number={5}, journal={IEEE Transactions on Computer-aided Design of Integrated Circuits and Systems}, author={Melamed, S. and Thorolfsson, T. and Harris, T. R. and Priyadarshi, S. and Franzon, Paul and Steer, M. B. and Davis, W. R.}, year={2012}, pages={676–689} }
 @inproceedings{harris_melamed_luniya_davis_steer_doxsee_obermiller_hawkinson_2010, title={Thermal analysis and verification of a mounted monolithic integrated circuit}, ISSN={["1558-058X"]}, DOI={10.1109/secon.2010.5453924}, abstractNote={As circuit density increases and high-power applications are facilitated, thermal considerations become paramount a design concern. In this paper, a high power monolithic microwave integrated circuit (MMIC) is modeled by the fREEDA multi-physics simulator and measured for validation. While validation is the crux of any simulation model, it is known that thermal measurements accurate to a high resolution are problematic. As such, the thermal profile of integrated circuits cannot be measured directly with infrared thermal imaging due to unequivalent emissivities of materials. It becomes necessary to use an absorptive ink to approximate a blackbody so that the infrared emissions can be used to infer temperature. The impact and effect of this thermal imaging technique is investigated in this work by comparing measurements with detailed thermal simulations with and without the surface treatment. Thermal analysis uses the finite element method and a reduced-order model based on cuboids with effective thermal conductivities. The end goal is to provide a simulation tool to designers, which can be extended to any project which requires attention to thermal preference.}, booktitle={Proceedings of the IEEE SoutheastCon 2010 (SoutheastCon)}, author={Harris, T.R. and Melamed, S. and Luniya, S. and Davis, W.R. and Steer, M.B. and Doxsee, L.E. and Obermiller, K. and Hawkinson, C.}, year={2010}, pages={37–40} }