Pub Date : 2013-12-02DOI: 10.1109/THERMINIC.2013.6675204
C. Herold, M. Beier, J. Lutz, A. Hensler
This paper discusses how the square-root-t method improves the measurement of the virtual junction temperature Tvj in a power cycling test setup. By applying this method, the measurement becomes more tolerant to measurement delays and EMC noise, thus it enables to sharpen the basis of life time estimations. However the virtual junction temperature remains a one dimensional mapping of the three-dimensional temperature gradient which combined with CTE-mismatch induces stress in the interconnection materials. Therefore Tvj-measurement data are compared to statements found in IR-images.
{"title":"Improving the accuracy of junction temperature measurement with the square-root-t method","authors":"C. Herold, M. Beier, J. Lutz, A. Hensler","doi":"10.1109/THERMINIC.2013.6675204","DOIUrl":"https://doi.org/10.1109/THERMINIC.2013.6675204","url":null,"abstract":"This paper discusses how the square-root-t method improves the measurement of the virtual junction temperature Tvj in a power cycling test setup. By applying this method, the measurement becomes more tolerant to measurement delays and EMC noise, thus it enables to sharpen the basis of life time estimations. However the virtual junction temperature remains a one dimensional mapping of the three-dimensional temperature gradient which combined with CTE-mismatch induces stress in the interconnection materials. Therefore Tvj-measurement data are compared to statements found in IR-images.","PeriodicalId":369128,"journal":{"name":"19th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125489652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-02DOI: 10.1109/THERMINIC.2013.6675224
R. Schacht, S. Rzepka, B. Michel
A parametric transient thermo-electrical coupled PSPICE macro model for a power cable as well as the verification results of the experimental and finite element simulation will be introduced. The paper describes the modeling and simulation of a simplified, single-core cable parametric model, for the use in a circuit simulator e.g. PSPICE. The verification of the simulation data between ANSYS and PSPICE has shown good results. The results of comparison between PSPICE and the experimental data are suitable. With the introduced PSPICE cable model it is now possible to model quickly at system level under various thermal conditions and cable geometries and to have time saving transient thermo-electrical simulation results to overlook the thermal influences and temperatures along the power cable and to optimize e.g. the size, weight (copper diameter, used insulating material) of the power cable under real `thermal' assembling conditions in a e.g. car or truck.
{"title":"Parametric transient thermo-electrical PSPICE model for a power cable","authors":"R. Schacht, S. Rzepka, B. Michel","doi":"10.1109/THERMINIC.2013.6675224","DOIUrl":"https://doi.org/10.1109/THERMINIC.2013.6675224","url":null,"abstract":"A parametric transient thermo-electrical coupled PSPICE macro model for a power cable as well as the verification results of the experimental and finite element simulation will be introduced. The paper describes the modeling and simulation of a simplified, single-core cable parametric model, for the use in a circuit simulator e.g. PSPICE. The verification of the simulation data between ANSYS and PSPICE has shown good results. The results of comparison between PSPICE and the experimental data are suitable. With the introduced PSPICE cable model it is now possible to model quickly at system level under various thermal conditions and cable geometries and to have time saving transient thermo-electrical simulation results to overlook the thermal influences and temperatures along the power cable and to optimize e.g. the size, weight (copper diameter, used insulating material) of the power cable under real `thermal' assembling conditions in a e.g. car or truck.","PeriodicalId":369128,"journal":{"name":"19th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122700112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-02DOI: 10.1109/THERMINIC.2013.6675225
A. Zimmermann, Klaus-Volker Schutt
Polymers are important enablers for electronic systems. Current trends and challenges for the application of polymers in electronics are described. The transition to electro mobility leads to rising power density of automotive electronics. Therefore, polymers with high thermal stability and excellent heat dissipation are required. Within the EU funded FP7 project NANOPACK, Bosch investigated different thermal greases on a specific demonstrator. The results are described and discussed with focus on thermal performance and reliability.
{"title":"Polymers in power electronics - Performance of thermal interface materials","authors":"A. Zimmermann, Klaus-Volker Schutt","doi":"10.1109/THERMINIC.2013.6675225","DOIUrl":"https://doi.org/10.1109/THERMINIC.2013.6675225","url":null,"abstract":"Polymers are important enablers for electronic systems. Current trends and challenges for the application of polymers in electronics are described. The transition to electro mobility leads to rising power density of automotive electronics. Therefore, polymers with high thermal stability and excellent heat dissipation are required. Within the EU funded FP7 project NANOPACK, Bosch investigated different thermal greases on a specific demonstrator. The results are described and discussed with focus on thermal performance and reliability.","PeriodicalId":369128,"journal":{"name":"19th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117001365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-02DOI: 10.1109/THERMINIC.2013.6675229
J. Heilmann, I. Nikitin, D. May, K. Pressel, B. Wunderle
This paper proposes a guideline for the mechanical acceleration of end-of-lifetime prognostics of metal based thermal interfaces. As die attach material, we used an advanced nano-effect sintered silver layer as interface between die and steel substrate which has very good electrical and thermal conductivities. Two types of experiments/simulations are scheduled. A mechanical 4-pt bending experiment to cause the specimens to undergo fatigue failure rapidly as well as a thermal strain induced fatigue by thermal cycling for comparison. The manufactured specimens are designed to be used for both. With a Finite Element (FE)-model it is possible to simulate the accumulated von Mises strain as failure parameter to generate a lifetime model. Most of the work is currently in progress and results will be delivered soon as full paper.
{"title":"Reliability of advanced thermal interface technologies based on sintered die-attach materials","authors":"J. Heilmann, I. Nikitin, D. May, K. Pressel, B. Wunderle","doi":"10.1109/THERMINIC.2013.6675229","DOIUrl":"https://doi.org/10.1109/THERMINIC.2013.6675229","url":null,"abstract":"This paper proposes a guideline for the mechanical acceleration of end-of-lifetime prognostics of metal based thermal interfaces. As die attach material, we used an advanced nano-effect sintered silver layer as interface between die and steel substrate which has very good electrical and thermal conductivities. Two types of experiments/simulations are scheduled. A mechanical 4-pt bending experiment to cause the specimens to undergo fatigue failure rapidly as well as a thermal strain induced fatigue by thermal cycling for comparison. The manufactured specimens are designed to be used for both. With a Finite Element (FE)-model it is possible to simulate the accumulated von Mises strain as failure parameter to generate a lifetime model. Most of the work is currently in progress and results will be delivered soon as full paper.","PeriodicalId":369128,"journal":{"name":"19th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128432444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-02DOI: 10.1109/THERMINIC.2013.6675238
E. Bándy, A. Foldvary, M. Rencz
This paper studies the typical solar cell applications of spin-on silicate glass layers (Filmtronics Inc. 15A and 20B) in function of the applied heat treatment. The masking capability in wet etching procedures, like surface texturing and long-time anisotropic etching used in semitransparent solar cells, and also the surface passivation characteristics of p-type surfaces were examined. Optical microscopy inspections sustain the suitability in wet etching procedures of different temperature cured SOG layers. The best masking results in long-time anisotropic etching were gained for 800°C, N2 gas cured 20B layer. Microwave induced photoconductive decay (μ-PCD) measurements were conducted to reveal the lifetime changes that occur compared to raw material of differently passivated samples: Si3N4, SiO2 and spin-on glass layers cured at distinct temperatures. The measurements confirm a significant lifetime increase reached in case of 800°C, O2 gas cured 15A layer.
{"title":"The effect of heat treatment on spin-on oxide glasses in solar cell application","authors":"E. Bándy, A. Foldvary, M. Rencz","doi":"10.1109/THERMINIC.2013.6675238","DOIUrl":"https://doi.org/10.1109/THERMINIC.2013.6675238","url":null,"abstract":"This paper studies the typical solar cell applications of spin-on silicate glass layers (Filmtronics Inc. 15A and 20B) in function of the applied heat treatment. The masking capability in wet etching procedures, like surface texturing and long-time anisotropic etching used in semitransparent solar cells, and also the surface passivation characteristics of p-type surfaces were examined. Optical microscopy inspections sustain the suitability in wet etching procedures of different temperature cured SOG layers. The best masking results in long-time anisotropic etching were gained for 800°C, N2 gas cured 20B layer. Microwave induced photoconductive decay (μ-PCD) measurements were conducted to reveal the lifetime changes that occur compared to raw material of differently passivated samples: Si3N4, SiO2 and spin-on glass layers cured at distinct temperatures. The measurements confirm a significant lifetime increase reached in case of 800°C, O2 gas cured 15A layer.","PeriodicalId":369128,"journal":{"name":"19th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128340712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-02DOI: 10.1109/THERMINIC.2013.6675219
V. Kosel, M. Schipani, E. Seebacher
A simulation approach on system level is presented. The miniaturization of semiconductor devices causes higher power dissipation density on chip in comparison to predecessors. Therefore fast simulation techniques are required to identify thermal risks in the circuits and to make thermal optimization already in the design phase prior to mass production. The FEM simulators provide accurate results at the expense of long simulation time. However, in the concept or design phase a fast estimation of temperature is needed and an accuracy of 5-15% is usually acceptable. The FEM simulators are not integrated part of IC design tools and require additional skills of designers. To facilitate the work of designers a simulation approach on system level is introduced. The basis is a thermal library implemented in the Cadence environment. The particular parts of the thermal system like die, die attach, metal-oxide-layer, power metallization, lead-frame etc. are implemented as VHDL-AMS instances in this library. Every instance consists of one dimensional T topology RC network rather than non-physical Foster one. This network represents a truncated pyramid consisting of N exponentially distributed cuboids.
{"title":"Non-linear thermal simulations of semiconductor devices on system level","authors":"V. Kosel, M. Schipani, E. Seebacher","doi":"10.1109/THERMINIC.2013.6675219","DOIUrl":"https://doi.org/10.1109/THERMINIC.2013.6675219","url":null,"abstract":"A simulation approach on system level is presented. The miniaturization of semiconductor devices causes higher power dissipation density on chip in comparison to predecessors. Therefore fast simulation techniques are required to identify thermal risks in the circuits and to make thermal optimization already in the design phase prior to mass production. The FEM simulators provide accurate results at the expense of long simulation time. However, in the concept or design phase a fast estimation of temperature is needed and an accuracy of 5-15% is usually acceptable. The FEM simulators are not integrated part of IC design tools and require additional skills of designers. To facilitate the work of designers a simulation approach on system level is introduced. The basis is a thermal library implemented in the Cadence environment. The particular parts of the thermal system like die, die attach, metal-oxide-layer, power metallization, lead-frame etc. are implemented as VHDL-AMS instances in this library. Every instance consists of one dimensional T topology RC network rather than non-physical Foster one. This network represents a truncated pyramid consisting of N exponentially distributed cuboids.","PeriodicalId":369128,"journal":{"name":"19th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131391053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-02DOI: 10.1109/THERMINIC.2013.6675197
Z. Sárkány, A. Vass-Várnai, G. Hantos, M. Rencz
This article describes a possible method to assess the long-time behaviour of IGBT modules using the combination of power cycles to stress the devices and thermal transient testing to monitor possible die-attach degradation. The failure of an IGBT module is a complex phenomenon; it consists of thermal, electrical and thermo-mechanical effects. After a theoretical overview of the possible mechanisms, a detailed description on the structure of selected IGBT module and the power cycling parameters is given. To better understand the temperature distribution on the device and the reason of the failure after the cycling, the module was opened up, inspected visually and an equivalent thermal model was built and calibrated to the physical test results. Failure mechanisms such as die attach resistance increase, wire bond cracking and gate oxide degradation were detected.
{"title":"Failure prediction of IGBT modules based on power cycling tests","authors":"Z. Sárkány, A. Vass-Várnai, G. Hantos, M. Rencz","doi":"10.1109/THERMINIC.2013.6675197","DOIUrl":"https://doi.org/10.1109/THERMINIC.2013.6675197","url":null,"abstract":"This article describes a possible method to assess the long-time behaviour of IGBT modules using the combination of power cycles to stress the devices and thermal transient testing to monitor possible die-attach degradation. The failure of an IGBT module is a complex phenomenon; it consists of thermal, electrical and thermo-mechanical effects. After a theoretical overview of the possible mechanisms, a detailed description on the structure of selected IGBT module and the power cycling parameters is given. To better understand the temperature distribution on the device and the reason of the failure after the cycling, the module was opened up, inspected visually and an equivalent thermal model was built and calibrated to the physical test results. Failure mechanisms such as die attach resistance increase, wire bond cracking and gate oxide degradation were detected.","PeriodicalId":369128,"journal":{"name":"19th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134197144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-02DOI: 10.1109/THERMINIC.2013.6675216
Y. Ni, J. Ordonez-Miranda, Y. Chalopin, S. Volz
We studied the heat propagation in Ti/Pt/Au micro-heater embedded thermal testing chips by computer simulations. Graphene was considered to be incorporated within the chips as a heat spreader in order to utilize its extremely high thermal conductivity. The classical heat conduction equation was solved numerically using the finite element analysis method. We found a linear relation between the temperature of the hot spot and the imposed heat flux, and a graphene spreader could effectively decrease the temperature of the micro-heater. These findings are in satisfying agreement with experimental measurements. In order to better understand the mechanisms behind these phenomena, the temperature distribution along the device surface was plotted and compared for systems with and without a graphene spreader. These results provide a better insight of graphene-based materials as heat spreaders and yield useful information to help improving heat removal from electronic devices.
{"title":"Modelling of graphene and few-layer graphene heat spreaders for hot-spot cooling","authors":"Y. Ni, J. Ordonez-Miranda, Y. Chalopin, S. Volz","doi":"10.1109/THERMINIC.2013.6675216","DOIUrl":"https://doi.org/10.1109/THERMINIC.2013.6675216","url":null,"abstract":"We studied the heat propagation in Ti/Pt/Au micro-heater embedded thermal testing chips by computer simulations. Graphene was considered to be incorporated within the chips as a heat spreader in order to utilize its extremely high thermal conductivity. The classical heat conduction equation was solved numerically using the finite element analysis method. We found a linear relation between the temperature of the hot spot and the imposed heat flux, and a graphene spreader could effectively decrease the temperature of the micro-heater. These findings are in satisfying agreement with experimental measurements. In order to better understand the mechanisms behind these phenomena, the temperature distribution along the device surface was plotted and compared for systems with and without a graphene spreader. These results provide a better insight of graphene-based materials as heat spreaders and yield useful information to help improving heat removal from electronic devices.","PeriodicalId":369128,"journal":{"name":"19th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128956739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-02DOI: 10.1109/THERMINIC.2013.6675210
E. Monier-Vinard, V. Bissuel, C. Dia, O. Daniel, N. Laraqi
Recent works on System-In-Package component pointed out that its in-package inductor is the hottest part. It occurs that thermal stresses due to joule heating and magnetic losses can be damaging. The present study focuses on low profile, surface-mounted, Soft Magnetic Composite inductors to define their thermal behaviour and then to propose a guideline to create pertinent models.Results highlight the impact of thermal conductivity of composite core on temperatures and the lack of properties data of iron-resin mixtures. Using mixture model, a calculation of effective thermal conductivity is proposed.To minimize the expensive meshing of the fine detailed simulations and the computation time, a novel Compact Thermal Model for inductor, based on DELPHI methodology, was established. The predictions of CTM model show good agreement, less than 10% of divergence. Further works must be done to really master the coupled interaction of magnetic, joule effect, thermal phenomenon as well as material properties.
{"title":"Investigation of Delphi compact thermal model style for modeling surface-mounted Soft Magnetic Composite inductor","authors":"E. Monier-Vinard, V. Bissuel, C. Dia, O. Daniel, N. Laraqi","doi":"10.1109/THERMINIC.2013.6675210","DOIUrl":"https://doi.org/10.1109/THERMINIC.2013.6675210","url":null,"abstract":"Recent works on System-In-Package component pointed out that its in-package inductor is the hottest part. It occurs that thermal stresses due to joule heating and magnetic losses can be damaging. The present study focuses on low profile, surface-mounted, Soft Magnetic Composite inductors to define their thermal behaviour and then to propose a guideline to create pertinent models.Results highlight the impact of thermal conductivity of composite core on temperatures and the lack of properties data of iron-resin mixtures. Using mixture model, a calculation of effective thermal conductivity is proposed.To minimize the expensive meshing of the fine detailed simulations and the computation time, a novel Compact Thermal Model for inductor, based on DELPHI methodology, was established. The predictions of CTM model show good agreement, less than 10% of divergence. Further works must be done to really master the coupled interaction of magnetic, joule effect, thermal phenomenon as well as material properties.","PeriodicalId":369128,"journal":{"name":"19th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132881820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-02DOI: 10.1109/THERMINIC.2013.6675244
J. Reparaz, E. Chávez‐Ángel, J. Gomis-Bresco, M. R. Wagner, A. Shchepetov, M. Prunnila, J. Ahopelto, F. Alzina, C. S. Sotomayor Torres
We report on the reduction of the thermal conductivity in ultra-thin suspended Si membranes with high crystalline quality at room temperature. A series of membranes with thicknesses ranging from 9 nm to 1.5 μm was investigated using Raman thermometry, a novel contactless optical technique for thermal conductivity determination. The temperature rise of a laser spot focused on the membranes was monitored as a function of the absorbed power. For this purpose, the absorption coefficient of the membranes was experimentally determined and also theoretically modelled. A systematic decrease in the thermal conductivity was observed as reducing the thickness of the membranes which is explained using the Fuchs-Sondheimer model through the influence of phonon boundary scattering at the surfaces of the membranes. The thermal conductivity of the thinnest membrane with d= 9 nm resulted in (9±2)W/mK, thus approaching the amorphous limit but still maintaining a high crystalline quality.
{"title":"Thermal conductivity reduction in Si free-standing membranes investigated using Raman thermometry","authors":"J. Reparaz, E. Chávez‐Ángel, J. Gomis-Bresco, M. R. Wagner, A. Shchepetov, M. Prunnila, J. Ahopelto, F. Alzina, C. S. Sotomayor Torres","doi":"10.1109/THERMINIC.2013.6675244","DOIUrl":"https://doi.org/10.1109/THERMINIC.2013.6675244","url":null,"abstract":"We report on the reduction of the thermal conductivity in ultra-thin suspended Si membranes with high crystalline quality at room temperature. A series of membranes with thicknesses ranging from 9 nm to 1.5 μm was investigated using Raman thermometry, a novel contactless optical technique for thermal conductivity determination. The temperature rise of a laser spot focused on the membranes was monitored as a function of the absorbed power. For this purpose, the absorption coefficient of the membranes was experimentally determined and also theoretically modelled. A systematic decrease in the thermal conductivity was observed as reducing the thickness of the membranes which is explained using the Fuchs-Sondheimer model through the influence of phonon boundary scattering at the surfaces of the membranes. The thermal conductivity of the thinnest membrane with d= 9 nm resulted in (9±2)W/mK, thus approaching the amorphous limit but still maintaining a high crystalline quality.","PeriodicalId":369128,"journal":{"name":"19th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132292005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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