The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform

Ji Yufeng - One of the best experts on this subject based on the ideXlab platform.

  • Investigation of a Unified LTCC-based Micromachining and Packaging Platform for High Density/Multifunctional Microsystem Integration
    2012
    Co-Authors: Mi Miao, Ji Yufeng, Qiu Yunsong, Zhang Jing, Zhang Yangfei, Ga Hua, Li Zhensong, Zhang Yang, Cao Rui, Wang Zhengyi
    Abstract:

    3D system-in-package has recently been considered a major enabler for high density and heterogeneous microsystem integration. We hereby proposed the concept of a unified micromachining and packaging platform based on LTCC (low temperature cofired ceramic) material system and process, which is implemented by first enhancing an existing LTCC hybrid IC fabrication line and then integrating different LTCC micromachining process modules one by one. Hence, the unified process flow can be accomplished within just one single package-test house. The platform has been capable of micromachining basic 3D MEMS (micro electromechanical system) microstructures into LTCC laminates and using them as a packaging substrate for mounting IC/MEMS from other process platforms, realizing self-contained and versatile microsystems of high density. The 3D microstructures formation process consisting of green tape machining, lamination and cofiring are demonstrated. The designing, analysis and fabricated samples of various micro functional structure enabled by the platform are illustrated, including embedded cooling microchannels (capable of lowering substrate temperature by more than 50K), microaccelerometer for harsh environment, micro Pirani Gauge for in-situ vacuum level monitoring and THz (tera hertz) vacuum microelectronic devices. Samples of overall packaged MEMS and IC chips with micromachined LTCC substrate are displayed, showing ultra-low leakage (< 5 x 10(-11) Pa . m(3)/s) vacuum packaging capability and significantly enhanced device performance. In addition, the platform has demonstrated the potential of stacking several laminates with mounted chips into a 3D frame-like microsystem. In comparison, 3D integration purely based on Si micromachining, e. g. anodic-bonding based in-situ wafer encapsulation, may only support a very limited spectrum of devices/materials and integration density and is somehow too expensive for many MEMS researchers.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000309162000062&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Computer Science, Hardware & ArchitectureEngineering, Electrical & ElectronicEICPCI-S(ISTP)

  • A LTCC microsystem vacuum package substrate with embedded cooling microchannel and Pirani Gauge
    2010
    Co-Authors: Mi Miao, Ji Yufeng, Qiu Yunsong, Zhang Jing, Zhang Yangfei, Ga Hua
    Abstract:

    This paper reports the designing, simulation and initial experimental investigation into a LTCC vacuum microsystem package substrate acting both as a vital panel and a functional structure for compact system-in-package (SiP) integration. Design, validation and experimental results for microchannels with different planar axial shapes are presented. Experimental and simulated temperature distribution over the substrate demonstrate the effectiveness of microchannel design, with substrate temperature rise cut by over 70% compared with those without microchannels. The effect of vacuum on cooling is simulated and potential ways to enhance heat transfer are suggested. The structure and principles of a Pirani Gauge integrated onto the substrate are displayed. This micro Gauge is formed by wire bonded, instead of by micromachining, and is proved to be both simple and effective in in-situ vacuum measuring inside a compact package. Therefore, this substrate proves an promising option for SiP applications in defense, industrial and consumer domains demanding high packaging density and vacuum or airtight circumstances. ?2010 IEEE.EI

  • A micro in-situ Pirani vacuum Gauge for microsystem package applications
    2010
    Co-Authors: Ga Hua, Mi Miao, Qiu Yunsong, Ji Yufeng
    Abstract:

    A novel micro-Pirani vacuum Gauge applied in microsystem packages has been experimentally investigated. The Gauge consists of a micro metal hot-wire, which is bonded on the pads of the LTCC substrate of a microsystem package and hangs over a cavity micromachined into the substrate. With a simple structure, this Gauge may provide an in-situ and realtime monitoring of the vacuum inside the chamber of microsystem packages. This paper looks into the fundamental characteristics of this kind of micro-Pirani Gauge. The performance characteristic curves are measured for metal wires with various length and current load. Based on the data thus obtained, the impacting factors are found out to optimize the micro-Pirani Gauge. ? 2010 IEEE.EI

  • A Micro In-Situ Pirani Vacuum Gauge for Microsystem Package Applications
    2010
    Co-Authors: Ga Hua, Mi Miao, Qiu Yunsong, Ji Yufeng
    Abstract:

    A novel micro-Pirani vacuum Gauge applied in microsystem packages has been experimentally investigated. The Gauge consists of a micro metal hot-wire, which is bonded on the pads of the LTCC substrate of a microsystem package and hangs over a cavity micromachined into the substrate. With a simple structure, this Gauge may provide an in-situ and real-time monitoring of the vacuum inside the chamber of microsystem packages. This paper looks into the fundamental characteristics of this kind of micro-Pirani Gauge. The performance characteristic curves are measured for metal wires with various length and current load. Based on the data thus obtained, the impacting factors are found out to optimize the micro-Pirani Gauge.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000328124000028&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Engineering, Electrical & ElectronicCPCI-S(ISTP)

  • A vacuum/airtight package with multifunctional LTCC substrate and integrated Pirani vacuum Gauge for 3D SIP integration applications
    2010
    Co-Authors: Mi Miao, Ji Yufeng, Ga Hua, Li Zhensong
    Abstract:

    This paper reports the design and initial experimental investigation of a vacuum/airtight package, based on a multilayered LTCC substrate that acts not only as a chip carrier with flexible interconnects but an integrated panel with multiple functional structure. Design, validation and experimental results for various cooling microchannels embedded into the substrate are presented; the substrate temperature rise is cut by over 70% compared with substrate without microchannels. The effect of vacuum on cooling is simulated. A hot-wire micro Pirani Gauge are integrated onto the substrate by wire bonding for a simple and effective in-situ vacuum measuring. The packaged sample display a leakage rate of lower than 10-12 Pa &middot m3/s. Therefore, this packaging can be an optimal choice for 3D system-in-package applications demanding high integration density, medium vacuum circumstance and long usage/storage lifecycle. ?2010 IEEE.EI

Mi Miao - One of the best experts on this subject based on the ideXlab platform.

  • Investigation of a Unified LTCC-based Micromachining and Packaging Platform for High Density/Multifunctional Microsystem Integration
    2012
    Co-Authors: Mi Miao, Ji Yufeng, Qiu Yunsong, Zhang Jing, Zhang Yangfei, Ga Hua, Li Zhensong, Zhang Yang, Cao Rui, Wang Zhengyi
    Abstract:

    3D system-in-package has recently been considered a major enabler for high density and heterogeneous microsystem integration. We hereby proposed the concept of a unified micromachining and packaging platform based on LTCC (low temperature cofired ceramic) material system and process, which is implemented by first enhancing an existing LTCC hybrid IC fabrication line and then integrating different LTCC micromachining process modules one by one. Hence, the unified process flow can be accomplished within just one single package-test house. The platform has been capable of micromachining basic 3D MEMS (micro electromechanical system) microstructures into LTCC laminates and using them as a packaging substrate for mounting IC/MEMS from other process platforms, realizing self-contained and versatile microsystems of high density. The 3D microstructures formation process consisting of green tape machining, lamination and cofiring are demonstrated. The designing, analysis and fabricated samples of various micro functional structure enabled by the platform are illustrated, including embedded cooling microchannels (capable of lowering substrate temperature by more than 50K), microaccelerometer for harsh environment, micro Pirani Gauge for in-situ vacuum level monitoring and THz (tera hertz) vacuum microelectronic devices. Samples of overall packaged MEMS and IC chips with micromachined LTCC substrate are displayed, showing ultra-low leakage (< 5 x 10(-11) Pa . m(3)/s) vacuum packaging capability and significantly enhanced device performance. In addition, the platform has demonstrated the potential of stacking several laminates with mounted chips into a 3D frame-like microsystem. In comparison, 3D integration purely based on Si micromachining, e. g. anodic-bonding based in-situ wafer encapsulation, may only support a very limited spectrum of devices/materials and integration density and is somehow too expensive for many MEMS researchers.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000309162000062&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Computer Science, Hardware & ArchitectureEngineering, Electrical & ElectronicEICPCI-S(ISTP)

  • a vacuum airtight package with multifunctional ltcc substrate and integrated Pirani vacuum Gauge for 3d sip integration applications
    IEEE International Conference on Solid-State and Integrated Circuit Technology, 2010
    Co-Authors: Mi Miao
    Abstract:

    This paper reports the design and initial experimental investigation of a vacuum/airtight package, based on a multilayered LTCC substrate that acts not only as a chip carrier with flexible interconnects but an integrated panel with multiple functional structure. Design, validation and experimental results for various cooling microchannels embedded into the substrate are presented; the substrate temperature rise is cut by over 70% compared with substrate without microchannels. The effect of vacuum on cooling is simulated. A hot-wire micro Pirani Gauge are integrated onto the substrate by wire bonding for a simple and effective in-situ vacuum measuring. The packaged sample display a leakage rate of lower than 10 −12 Pa · m3/s. Therefore, this packaging can be an optimal choice for 3D system-in-package applications demanding high integration density, medium vacuum circumstance and long usage/storage lifecycle.

  • a ltcc microsystem vacuum package substrate with embedded cooling microchannel and Pirani Gauge
    Nano Micro Engineered and Molecular Systems, 2010
    Co-Authors: Mi Miao, Yunsong Qiu, Jing Zhang, Yangfei Zhang
    Abstract:

    This paper reports the designing, simulation and initial experimental investigation into a LTCC vacuum microsystem package substrate acting both as a vital panel and a functional structure for compact system-in-package (SiP) integration. Design, validation and experimental results for microchannels with different planar axial shapes are presented. Experimental and simulated temperature distribution over the substrate demonstrate the effectiveness of microchannel design, with substrate temperature rise cut by over 70% compared with those without microchannels. The effect of vacuum on cooling is simulated and potential ways to enhance heat transfer are suggested. The structure and principles of a Pirani Gauge integrated onto the substrate are displayed. This micro Gauge is formed by wire bonded, instead of by micromachining, and is proved to be both simple and effective in in-situ vacuum measuring inside a compact package. Therefore, this substrate proves an promising option for SiP applications in defense, industrial and consumer domains demanding high packaging density and vacuum or airtight circumstances.

  • a micro in situ Pirani vacuum Gauge for microsystem package applications
    International Conference on Electronic Packaging Technology, 2010
    Co-Authors: Yunsong Qiu, Mi Miao
    Abstract:

    A novel micro-Pirani vacuum Gauge applied in micro-system packages has been experimentally investigated. The Gauge consists of a micro metal hot-wire, which is bonded on the pads of the LTCC substrate of a microsystem package and hangs over a cavity micromachined into the substrate. With a simple structure, this Gauge may provide an in-situ and real-time monitoring of the vacuum inside the chamber of microsystem packages. This paper looks into the fundamental characteristics of this kind of micro-Pirani Gauge. The performance characteristic curves are measured for metal wires with various length and current load. Based on the data thus obtained, the impacting factors are found out to optimize the micro-Pirani Gauge.

  • A LTCC microsystem vacuum package substrate with embedded cooling microchannel and Pirani Gauge
    2010
    Co-Authors: Mi Miao, Ji Yufeng, Qiu Yunsong, Zhang Jing, Zhang Yangfei, Ga Hua
    Abstract:

    This paper reports the designing, simulation and initial experimental investigation into a LTCC vacuum microsystem package substrate acting both as a vital panel and a functional structure for compact system-in-package (SiP) integration. Design, validation and experimental results for microchannels with different planar axial shapes are presented. Experimental and simulated temperature distribution over the substrate demonstrate the effectiveness of microchannel design, with substrate temperature rise cut by over 70% compared with those without microchannels. The effect of vacuum on cooling is simulated and potential ways to enhance heat transfer are suggested. The structure and principles of a Pirani Gauge integrated onto the substrate are displayed. This micro Gauge is formed by wire bonded, instead of by micromachining, and is proved to be both simple and effective in in-situ vacuum measuring inside a compact package. Therefore, this substrate proves an promising option for SiP applications in defense, industrial and consumer domains demanding high packaging density and vacuum or airtight circumstances. ?2010 IEEE.EI

P M Sarro - One of the best experts on this subject based on the ideXlab platform.

  • tube shaped Pirani Gauge for in situ hermeticity monitoring of sin thin film encapsulation
    Journal of Micromechanics and Microengineering, 2012
    Co-Authors: F Santagata, J F Creeme, E Iervolino, P M Sarro
    Abstract:

    Here the integration of a tube-shaped Pirani Gauge with a SiN thin-film encapsulation process is presented. The tube geometry gives the sensor a very low detection limit with a small footprint, since the tube is buried under the silicon surface. The Pirani tube is very suitable for in situ evaluation of MEMS vacuum packaging. Moreover, since the Pirani gap is all around the tube and deep below the silicon surface, the deflection of the encapsulation shell is not a concern and wafer-level measurement of the device is possible. Pirani tubes with different lengths are encapsulated inside SiN micropackages in order to measure the resulting vacuum level achieved after the encapsulation step. The longest tube shows a detection limit of 0.1 Pa for a noise level of 50 μV and it has a footprint of only 0.006 mm2. The pressure inside the sealed micropackage was extracted to be 0.7 kPa. Furthermore, the pressure is monitored over time to evaluate the hermeticity of the packages. A leak rate of 8× 10−18 Pa m3 s−1 was measured over four months time.

  • a tube shaped buried Pirani Gauge for low detection limit with small footprint
    IEEE\ ASME Journal of Microelectromechanical Systems, 2011
    Co-Authors: F Santagata, J F Creeme, E Iervolino, L Mele, A W Van Herwaarde, P M Sarro
    Abstract:

    We present a micromachined Pirani Gauge that combines low detection limit and strongly reduced footprint. It consists of a tube-shaped resistor that is buried in the silicon substrate. The choice of the tube geometry gives the resistor a very high structural rigidity. This enables the fabrication of much longer resistors, thus shifting the detection limit toward lower pressures. In addition, since the resistor is buried under the silicon surface, its footprint is kept very small. The high stiffness allowed the fabrication of a 3-mm-long and 1.8-μm-thick poly-Si tube with a 1-μm gap without buckling and/or stiction problems. It shows a detection limit of 0.1 Pa for a noise level of 50 μV, and it has a footprint of only 0.012 mm2. This is an improvement of at least 20 times compared with Pirani Gauges with the same detection limit. Pirani tubes of 1.6- and 0.4-mm lengths have also been designed, fabricated, and tested. The 0.4-mm-long tube shows a low pressure limit of 2 Pa, whereas the tube of 1.6 mm shows a low pressure limit of 0.2 Pa. The measured transfer functions correspond very well to the 1-D analytical model.

  • a novel 3 d tube shaped buried poly si Pirani Gauge for extended dynamic range with small footprint
    International Conference on Micro Electro Mechanical Systems, 2010
    Co-Authors: F Santagata, J F Creeme, E Iervolino, A W Van Herwaarde, J M W Laros, J Groeneweg, P M Sarro
    Abstract:

    We have developed a novel micromachined Pirani vacuum Gauge employing a tube-shaped 3-D structure with enhanced rigidity and very low footprint because it is completely buried inside the silicon substrate. A CMOS-compatible three masks process was used to realize this new design, which allowed the fabrication, without stiction problems of a 3.2 mm long Pirani poly-Si tube with a 1.5 µm gap. Compared to previous Gauges, the dynamic range is 100 times larger, ranging from 20 mPa to 10 kPa with a maximum sensitivity of 17.5 mV/decade.

Ga Hua - One of the best experts on this subject based on the ideXlab platform.

  • Investigation of a Unified LTCC-based Micromachining and Packaging Platform for High Density/Multifunctional Microsystem Integration
    2012
    Co-Authors: Mi Miao, Ji Yufeng, Qiu Yunsong, Zhang Jing, Zhang Yangfei, Ga Hua, Li Zhensong, Zhang Yang, Cao Rui, Wang Zhengyi
    Abstract:

    3D system-in-package has recently been considered a major enabler for high density and heterogeneous microsystem integration. We hereby proposed the concept of a unified micromachining and packaging platform based on LTCC (low temperature cofired ceramic) material system and process, which is implemented by first enhancing an existing LTCC hybrid IC fabrication line and then integrating different LTCC micromachining process modules one by one. Hence, the unified process flow can be accomplished within just one single package-test house. The platform has been capable of micromachining basic 3D MEMS (micro electromechanical system) microstructures into LTCC laminates and using them as a packaging substrate for mounting IC/MEMS from other process platforms, realizing self-contained and versatile microsystems of high density. The 3D microstructures formation process consisting of green tape machining, lamination and cofiring are demonstrated. The designing, analysis and fabricated samples of various micro functional structure enabled by the platform are illustrated, including embedded cooling microchannels (capable of lowering substrate temperature by more than 50K), microaccelerometer for harsh environment, micro Pirani Gauge for in-situ vacuum level monitoring and THz (tera hertz) vacuum microelectronic devices. Samples of overall packaged MEMS and IC chips with micromachined LTCC substrate are displayed, showing ultra-low leakage (< 5 x 10(-11) Pa . m(3)/s) vacuum packaging capability and significantly enhanced device performance. In addition, the platform has demonstrated the potential of stacking several laminates with mounted chips into a 3D frame-like microsystem. In comparison, 3D integration purely based on Si micromachining, e. g. anodic-bonding based in-situ wafer encapsulation, may only support a very limited spectrum of devices/materials and integration density and is somehow too expensive for many MEMS researchers.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000309162000062&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Computer Science, Hardware & ArchitectureEngineering, Electrical & ElectronicEICPCI-S(ISTP)

  • A LTCC microsystem vacuum package substrate with embedded cooling microchannel and Pirani Gauge
    2010
    Co-Authors: Mi Miao, Ji Yufeng, Qiu Yunsong, Zhang Jing, Zhang Yangfei, Ga Hua
    Abstract:

    This paper reports the designing, simulation and initial experimental investigation into a LTCC vacuum microsystem package substrate acting both as a vital panel and a functional structure for compact system-in-package (SiP) integration. Design, validation and experimental results for microchannels with different planar axial shapes are presented. Experimental and simulated temperature distribution over the substrate demonstrate the effectiveness of microchannel design, with substrate temperature rise cut by over 70% compared with those without microchannels. The effect of vacuum on cooling is simulated and potential ways to enhance heat transfer are suggested. The structure and principles of a Pirani Gauge integrated onto the substrate are displayed. This micro Gauge is formed by wire bonded, instead of by micromachining, and is proved to be both simple and effective in in-situ vacuum measuring inside a compact package. Therefore, this substrate proves an promising option for SiP applications in defense, industrial and consumer domains demanding high packaging density and vacuum or airtight circumstances. ?2010 IEEE.EI

  • A micro in-situ Pirani vacuum Gauge for microsystem package applications
    2010
    Co-Authors: Ga Hua, Mi Miao, Qiu Yunsong, Ji Yufeng
    Abstract:

    A novel micro-Pirani vacuum Gauge applied in microsystem packages has been experimentally investigated. The Gauge consists of a micro metal hot-wire, which is bonded on the pads of the LTCC substrate of a microsystem package and hangs over a cavity micromachined into the substrate. With a simple structure, this Gauge may provide an in-situ and realtime monitoring of the vacuum inside the chamber of microsystem packages. This paper looks into the fundamental characteristics of this kind of micro-Pirani Gauge. The performance characteristic curves are measured for metal wires with various length and current load. Based on the data thus obtained, the impacting factors are found out to optimize the micro-Pirani Gauge. ? 2010 IEEE.EI

  • A Micro In-Situ Pirani Vacuum Gauge for Microsystem Package Applications
    2010
    Co-Authors: Ga Hua, Mi Miao, Qiu Yunsong, Ji Yufeng
    Abstract:

    A novel micro-Pirani vacuum Gauge applied in microsystem packages has been experimentally investigated. The Gauge consists of a micro metal hot-wire, which is bonded on the pads of the LTCC substrate of a microsystem package and hangs over a cavity micromachined into the substrate. With a simple structure, this Gauge may provide an in-situ and real-time monitoring of the vacuum inside the chamber of microsystem packages. This paper looks into the fundamental characteristics of this kind of micro-Pirani Gauge. The performance characteristic curves are measured for metal wires with various length and current load. Based on the data thus obtained, the impacting factors are found out to optimize the micro-Pirani Gauge.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000328124000028&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Engineering, Electrical & ElectronicCPCI-S(ISTP)

  • A vacuum/airtight package with multifunctional LTCC substrate and integrated Pirani vacuum Gauge for 3D SIP integration applications
    2010
    Co-Authors: Mi Miao, Ji Yufeng, Ga Hua, Li Zhensong
    Abstract:

    This paper reports the design and initial experimental investigation of a vacuum/airtight package, based on a multilayered LTCC substrate that acts not only as a chip carrier with flexible interconnects but an integrated panel with multiple functional structure. Design, validation and experimental results for various cooling microchannels embedded into the substrate are presented; the substrate temperature rise is cut by over 70% compared with substrate without microchannels. The effect of vacuum on cooling is simulated. A hot-wire micro Pirani Gauge are integrated onto the substrate by wire bonding for a simple and effective in-situ vacuum measuring. The packaged sample display a leakage rate of lower than 10-12 Pa &middot m3/s. Therefore, this packaging can be an optimal choice for 3D system-in-package applications demanding high integration density, medium vacuum circumstance and long usage/storage lifecycle. ?2010 IEEE.EI

Silva, Ubirata Correia - One of the best experts on this subject based on the ideXlab platform.

  • Implementação da técnica de difração de elétrons de baixa energia
    Universidade Federal do Rio Grande do Norte, 2010
    Co-Authors: Silva, Ubirata Correia
    Abstract:

    O objetivo deste trabalho é descrever a implementação da técnica de Difração de elétrons de Baixa Energia (Low Energy Electron Diffaction - LEED) no Laboratório de Nanoestruturas Magnéticas e Semicondutoras do Departamento de Física Teórica e Experimental da UFRN. Ao longo deste trabalho, foram realizadas implementações de aparatos experimentais para a completa montagem do LEED. Um novo sistema de vácuo foi montado, este é composto pela bomba mecânica, bomba turbomolecular e bomba iônica para ultra alto vácuo e seus respectivos sensores de medidas de pressão (medidor Pirani, para medidas de baixo vácuo e o medidor de alcance amplo WRG); manutenção do canhão de ions, que é basicamente um mini-sputtering, com função de limpeza das amostras; montagem, manutenção e manuseio do espectrômetro de massa por quadrupolo, cuja finalidade principal é investigar a contaminação gasosa no interior da câmara de ultra alto vácuo. Destaque-se, que a principal contribuição deste trabalho foi a montagem do sistema de aquecimento da amostra, ou seja, um novo porta-amostra. Neste além da função de porta-amostra e aquecedor, foi necessário implementar a função de sustentação no ambiente de ultra-alto vácuo. Esse conjunto de ações é fundamental para o funcionamento completo da técnica LEEDThe purpose of this study is to describe the implementation of the Low Energy Electron Diffaction (LEED) technique in the Laboratory of Magnetic Nanostructures and Semiconductors of the Department of Theoretical and Experimental Physics of the Universidade Federal do Rio Grande do Norte (UFRN), Natal, Brazil. During this work experimental apparatus were implemented for a complete LEED set-up. A new vacuum system was also set up. This was composed of a mechanical pump, turbomolecular pump and ionic pump for ultra-high vacuum and their respective pressure measurement sensors (Pirani Gauge for low vacuum measures and the wide range Gauge -WRG); ion cannon maintenance, which is basically mini-sputtering, whose function is sample cleaning; and set-up, maintenance and handling of the quadrupole mass spectrometer, whose main purpose is to investigate gas contamination inside the ultra-high vacuum chamber. It should be pointed out that the main contribution of this Master's thesis was the set-up of the sample heating system; that is, a new sample holder. In addition to the function of sample holder and heater, it was necessary to implement the function of sustaining the ultra-high vacuum environment. This set of actions is essential for the complete functioning of the LEED techniqu

  • Implementação da técnica de difração de elétrons de baixa energia
    Física da Matéria Condensada; Astrofísica e Cosmologia; Física da Ionosfera, 2010
    Co-Authors: Silva, Ubirata Correia
    Abstract:

    The purpose of this study is to describe the implementation of the Low Energy Electron Diffaction (LEED) technique in the Laboratory of Magnetic Nanostructures and Semiconductors of the Department of Theoretical and Experimental Physics of the Universidade Federal do Rio Grande do Norte (UFRN), Natal, Brazil. During this work experimental apparatus were implemented for a complete LEED set-up. A new vacuum system was also set up. This was composed of a mechanical pump, turbomolecular pump and ionic pump for ultra-high vacuum and their respective pressure measurement sensors (Pirani Gauge for low vacuum measures and the wide range Gauge -WRG); ion cannon maintenance, which is basically mini-sputtering, whose function is sample cleaning; and set-up, maintenance and handling of the quadrupole mass spectrometer, whose main purpose is to investigate gas contamination inside the ultra-high vacuum chamber. It should be pointed out that the main contribution of this Master's thesis was the set-up of the sample heating system; that is, a new sample holder. In addition to the function of sample holder and heater, it was necessary to implement the function of sustaining the ultra-high vacuum environment. This set of actions is essential for the complete functioning of the LEED techniqueO objetivo deste trabalho é descrever a implementação da técnica de Difração de elétrons de Baixa Energia (Low Energy Electron Diffaction - LEED) no Laboratório de Nanoestruturas Magnéticas e Semicondutoras do Departamento de Física Teórica e Experimental da UFRN. Ao longo deste trabalho, foram realizadas implementações de aparatos experimentais para a completa montagem do LEED. Um novo sistema de vácuo foi montado, este é composto pela bomba mecânica, bomba turbomolecular e bomba iônica para ultra alto vácuo e seus respectivos sensores de medidas de pressão (medidor Pirani, para medidas de baixo vácuo e o medidor de alcance amplo WRG); manutenção do canhão de ions, que é basicamente um mini-sputtering, com função de limpeza das amostras; montagem, manutenção e manuseio do espectrômetro de massa por quadrupolo, cuja finalidade principal é investigar a contaminação gasosa no interior da câmara de ultra alto vácuo. Destaque-se, que a principal contribuição deste trabalho foi a montagem do sistema de aquecimento da amostra, ou seja, um novo porta-amostra. Neste além da função de porta-amostra e aquecedor, foi necessário implementar a função de sustentação no ambiente de ultra-alto vácuo. Esse conjunto de ações é fundamental para o funcionamento completo da técnica LEE