Materials based on the linear chain carbon (sp-bonds between atoms) and their applications are described. Such materials were found to be promising biomaterials. The materials are produced by specific chemical and physical processes. Carbion (an improved analogue of carbylan) has a polymeric basis, bearing on its surface a linear-chain carbon layer with long chains, oriented mainly along the surface. Carbion fiber and carbion-coated materials are prepared by chemical modification (via the dehydrohalogenation reaction of the original polymeric substance, namely polyvinylidene halide). The carbion materials and implants mentioned above are fibers knitted with carbion-coated fiber nets and other products (sutures, artificial knitted vascular vessels, urethras, etc.).
{"title":"New carbon based material layers for medical application","authors":"M. Guseva, V. Babaev, N. D. Novikov, N. Bistrova","doi":"10.1109/WBL.2001.946550","DOIUrl":"https://doi.org/10.1109/WBL.2001.946550","url":null,"abstract":"Materials based on the linear chain carbon (sp-bonds between atoms) and their applications are described. Such materials were found to be promising biomaterials. The materials are produced by specific chemical and physical processes. Carbion (an improved analogue of carbylan) has a polymeric basis, bearing on its surface a linear-chain carbon layer with long chains, oriented mainly along the surface. Carbion fiber and carbion-coated materials are prepared by chemical modification (via the dehydrohalogenation reaction of the original polymeric substance, namely polyvinylidene halide). The carbion materials and implants mentioned above are fibers knitted with carbion-coated fiber nets and other products (sutures, artificial knitted vascular vessels, urethras, etc.).","PeriodicalId":315832,"journal":{"name":"3rd International Conference 'Novel Applications of Wide Bandgap Layers' Abstract Book (Cat. No.01EX500)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114667146","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}
The authors present results on both temperature-dependent resistivity (/spl rho/(T)) measurements and current-voltage (I(V)) characteristics of polycrystalline diamond thin films chemically vapour deposited by hot filament (HF-CVD) method from propane-butane gas mixture diluted in hydrogen. The films were deposited on single crystal silicon substrates. In-plane and out-of-plane I-V characteristics of the same sample are shown and observed differences are discussed, which clearly attest to concurrent transport mechanisms in the films. Then, changes in the samples resistivity under heat treatment in vacuum are presented. The authors show that a simple exponential /spl rho/(T) model is inadequate to explain the results, since distinctive peaks are found in the characteristics. Further, observed changes are analysed in terms of gradual dehydrogenation of the samples. The results indicate that electrical properties of CVD diamond films may be to some extent controlled by their proper dehydrogenation either in vacuum or in an inert gas atmosphere.
{"title":"Changes in electrical properties of thin diamond films under heat treatment","authors":"S. Kulesza, F. Rozpłoch","doi":"10.1109/WBL.2001.946569","DOIUrl":"https://doi.org/10.1109/WBL.2001.946569","url":null,"abstract":"The authors present results on both temperature-dependent resistivity (/spl rho/(T)) measurements and current-voltage (I(V)) characteristics of polycrystalline diamond thin films chemically vapour deposited by hot filament (HF-CVD) method from propane-butane gas mixture diluted in hydrogen. The films were deposited on single crystal silicon substrates. In-plane and out-of-plane I-V characteristics of the same sample are shown and observed differences are discussed, which clearly attest to concurrent transport mechanisms in the films. Then, changes in the samples resistivity under heat treatment in vacuum are presented. The authors show that a simple exponential /spl rho/(T) model is inadequate to explain the results, since distinctive peaks are found in the characteristics. Further, observed changes are analysed in terms of gradual dehydrogenation of the samples. The results indicate that electrical properties of CVD diamond films may be to some extent controlled by their proper dehydrogenation either in vacuum or in an inert gas atmosphere.","PeriodicalId":315832,"journal":{"name":"3rd International Conference 'Novel Applications of Wide Bandgap Layers' Abstract Book (Cat. No.01EX500)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123809267","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}
G. Conte, P. Acarelli, E. Cappelli, A. Fidanzio, A. Piermattei, M. Rossi, S. Salvatori, C. Venanzi
The aim of this paper is to report on the tailoring of the physical properties of polycrystalline CVD diamond in order to fulfil the requirements of radiotherapy dosimeters. A very simple device geometry has been used to study the electronic response of the polycrystalline CVD layers and results achieved with a 6 MV bremsstrahlung X-ray beam delivered by a linear accelerator are presented and discussed.
{"title":"Radiotherapy dosimetry: a novel application for polycrystalline diamond thin films","authors":"G. Conte, P. Acarelli, E. Cappelli, A. Fidanzio, A. Piermattei, M. Rossi, S. Salvatori, C. Venanzi","doi":"10.1109/WBL.2001.946593","DOIUrl":"https://doi.org/10.1109/WBL.2001.946593","url":null,"abstract":"The aim of this paper is to report on the tailoring of the physical properties of polycrystalline CVD diamond in order to fulfil the requirements of radiotherapy dosimeters. A very simple device geometry has been used to study the electronic response of the polycrystalline CVD layers and results achieved with a 6 MV bremsstrahlung X-ray beam delivered by a linear accelerator are presented and discussed.","PeriodicalId":315832,"journal":{"name":"3rd International Conference 'Novel Applications of Wide Bandgap Layers' Abstract Book (Cat. No.01EX500)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114281523","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}
This paper reviews our recent achievements in homoepitaxial CVD diamond layers for electronic devices. We have successfully synthesized high quality homoepitaxial diamond layers with atomically flat surface by the microwave plasma chemical vapor deposition (CVD) using a low CH4 concentration of CH4/H2 gas system less than 0.15% CH4/H2 ratio and Ib (001) substrates with low-misorientation angle less than 1.5°. These layers have atomically flat and have excellent electrical and optical properties. For example, highquality Schottky junctions between Al and p-type high-conductivity layer near the surface of these layers have been obtained. Based on this growth method, we have also successfully synthesized B-doped diamond layers using trimethylboron [B(CH3)3,TMB] gas as a B doping source, whose Hall mobility is 1840 cm2/Vs at 290 K. Schottky junctions fabricated by the B-doped diamond also show excellent performances, indicating that the quality of these diamond layers is device grade.
{"title":"Diamond layers for active electronic devices","authors":"H. Okushi","doi":"10.1109/WBL.2001.946545","DOIUrl":"https://doi.org/10.1109/WBL.2001.946545","url":null,"abstract":"This paper reviews our recent achievements in homoepitaxial CVD diamond layers for electronic devices. We have successfully synthesized high quality homoepitaxial diamond layers with atomically flat surface by the microwave plasma chemical vapor deposition (CVD) using a low CH4 concentration of CH4/H2 gas system less than 0.15% CH4/H2 ratio and Ib (001) substrates with low-misorientation angle less than 1.5°. These layers have atomically flat and have excellent electrical and optical properties. For example, highquality Schottky junctions between Al and p-type high-conductivity layer near the surface of these layers have been obtained. Based on this growth method, we have also successfully synthesized B-doped diamond layers using trimethylboron [B(CH3)3,TMB] gas as a B doping source, whose Hall mobility is 1840 cm2/Vs at 290 K. Schottky junctions fabricated by the B-doped diamond also show excellent performances, indicating that the quality of these diamond layers is device grade.","PeriodicalId":315832,"journal":{"name":"3rd International Conference 'Novel Applications of Wide Bandgap Layers' Abstract Book (Cat. No.01EX500)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129118434","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}
W. Kaczorowski, A. Gołąbczak, J. Grabarczyk, P. Louda, P. Niedzielski
Nanocrystalline diamond has very attractive properties such as low friction coefficient, low wear resistance and chemical inertness. It also has a very high hardness. The characteristics of NCD makes it a good candidate for a wide range of tribological applications such as bearings, gears, cutting tools for machining non-ferrous metals, plastics, chip-board and composite materials. Hard carbon coatings are known to have good antisticking properties with respect to aluminum. In this paper, characterization experiments of nanocrystalline diamond for cutting aluminium are presented.
{"title":"Characterization of nanocrystalline diamond for cutting aluminium alloys","authors":"W. Kaczorowski, A. Gołąbczak, J. Grabarczyk, P. Louda, P. Niedzielski","doi":"10.1109/WBL.2001.946576","DOIUrl":"https://doi.org/10.1109/WBL.2001.946576","url":null,"abstract":"Nanocrystalline diamond has very attractive properties such as low friction coefficient, low wear resistance and chemical inertness. It also has a very high hardness. The characteristics of NCD makes it a good candidate for a wide range of tribological applications such as bearings, gears, cutting tools for machining non-ferrous metals, plastics, chip-board and composite materials. Hard carbon coatings are known to have good antisticking properties with respect to aluminum. In this paper, characterization experiments of nanocrystalline diamond for cutting aluminium are presented.","PeriodicalId":315832,"journal":{"name":"3rd International Conference 'Novel Applications of Wide Bandgap Layers' Abstract Book (Cat. No.01EX500)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130673814","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}
R. Kalish, V. Richter, B. Fizgeer, N. Koenigsfeld, Y. Avigal, A. Hoffman, E. Cheifetz, D. Hoxley
Electron emission from diamond surfaces has recently attracted much attention due to the outstanding physical and electrical properties of diamond (including the negative electron affinity (NEA) that some diamond surfaces exhibit). In general, induced electron emission from any material involves three stages: (I) the excitation of electrons in the bulk; (II) their transport to the surface and (III) the escape of the electrons into the vacuum. The ion induced electron emission (IIEE) yield (/spl gamma/) is defined as the number of emitted electrons per incident ion. It was found to depend on the electronic energy loss of the moving ion in the material. For clean metal surfaces /spl gamma/ is usually about 2-5, however for conducting, boron doped, hydrogenated diamond layers amazingly large values for the IIEE yield (reaching 150 for 200 keV proton bombardment) were recently reported. These large values suggest the use of diamond as a material for the realization of "single ion detectors". Furthermore, the unique way electron-hole pairs are created by ion impact, and the large depth inside the material where they are generated, may also shed light on the processes involved in the other forms of electron emission from diamond. Here the authors present results of IIEE from differently treated and different kinds of diamonds: (i) Boron doped CVD diamond on Si, grain size of the order of a few microns. (ii) Undoped CVD diamond layers, grain size of the order of a few microns. (iii) Boron doped CVD diamond thin layers with sub-micron grain size. (iv) Boron doped CVD diamond thin membranes (free standing) with sub-micron grain size, for which electrons emitted both backwards and forwards are measured.
{"title":"Ion-induced electron-emission from diamond","authors":"R. Kalish, V. Richter, B. Fizgeer, N. Koenigsfeld, Y. Avigal, A. Hoffman, E. Cheifetz, D. Hoxley","doi":"10.1109/WBL.2001.946546","DOIUrl":"https://doi.org/10.1109/WBL.2001.946546","url":null,"abstract":"Electron emission from diamond surfaces has recently attracted much attention due to the outstanding physical and electrical properties of diamond (including the negative electron affinity (NEA) that some diamond surfaces exhibit). In general, induced electron emission from any material involves three stages: (I) the excitation of electrons in the bulk; (II) their transport to the surface and (III) the escape of the electrons into the vacuum. The ion induced electron emission (IIEE) yield (/spl gamma/) is defined as the number of emitted electrons per incident ion. It was found to depend on the electronic energy loss of the moving ion in the material. For clean metal surfaces /spl gamma/ is usually about 2-5, however for conducting, boron doped, hydrogenated diamond layers amazingly large values for the IIEE yield (reaching 150 for 200 keV proton bombardment) were recently reported. These large values suggest the use of diamond as a material for the realization of \"single ion detectors\". Furthermore, the unique way electron-hole pairs are created by ion impact, and the large depth inside the material where they are generated, may also shed light on the processes involved in the other forms of electron emission from diamond. Here the authors present results of IIEE from differently treated and different kinds of diamonds: (i) Boron doped CVD diamond on Si, grain size of the order of a few microns. (ii) Undoped CVD diamond layers, grain size of the order of a few microns. (iii) Boron doped CVD diamond thin layers with sub-micron grain size. (iv) Boron doped CVD diamond thin membranes (free standing) with sub-micron grain size, for which electrons emitted both backwards and forwards are measured.","PeriodicalId":315832,"journal":{"name":"3rd International Conference 'Novel Applications of Wide Bandgap Layers' Abstract Book (Cat. No.01EX500)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130225171","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}
The aim of the project described in this paper was to examine the influence parameters of deposition and the method of location of samples on an RF-power electrode in the RF-PCVD method on the structure of carbon coatings, which covered cemented carbide substrates. This researches precedes an investigation concerning the covering of cemented carbide cutting tools by wear resistant carbon films, with were used in wood industry for milling of wood-base materials. As an object of investigation cutter head plates made of cemented carbide were used. Their size was about 30/spl times/12/spl times/1.5. In the deposition processes two types of parameters were applied: so-called "hard" parameters, when the bias voltage was higher then 500V, and "soft" parameters, when the bias voltage was less then 400V. In addition the flow of methane, pressure, and time of deposition were changed. In order to properly locate the cutting edge on the electrode three types of holders were used. Every process of depositing the carbon film on a cemented carbide substrate was preceded by one hour of ion etching.
{"title":"Forming carbon films on cemented carbide surface using RF PCVD method","authors":"J. Grabarczyk, P. Niedzielski, P. Louda","doi":"10.1109/WBL.2001.946562","DOIUrl":"https://doi.org/10.1109/WBL.2001.946562","url":null,"abstract":"The aim of the project described in this paper was to examine the influence parameters of deposition and the method of location of samples on an RF-power electrode in the RF-PCVD method on the structure of carbon coatings, which covered cemented carbide substrates. This researches precedes an investigation concerning the covering of cemented carbide cutting tools by wear resistant carbon films, with were used in wood industry for milling of wood-base materials. As an object of investigation cutter head plates made of cemented carbide were used. Their size was about 30/spl times/12/spl times/1.5. In the deposition processes two types of parameters were applied: so-called \"hard\" parameters, when the bias voltage was higher then 500V, and \"soft\" parameters, when the bias voltage was less then 400V. In addition the flow of methane, pressure, and time of deposition were changed. In order to properly locate the cutting edge on the electrode three types of holders were used. Every process of depositing the carbon film on a cemented carbide substrate was preceded by one hour of ion etching.","PeriodicalId":315832,"journal":{"name":"3rd International Conference 'Novel Applications of Wide Bandgap Layers' Abstract Book (Cat. No.01EX500)","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126190722","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}
P. Gielisse, H. Niculescu, J. Tremblay, S. Achmatowicz, M. Jakobowski, E. Zwierkowska, L. Golonka
The need for optimized thermal management in microelectronic devices derives from several sources, of which the ever-increasing miniaturization is only one. Power dissipation needs in certain designs are up to 40 W/cm/sup 2/, while 100 W/cm/sup 2/ is said to be required in the not too distant future. New multilayer ceramic integrated circuits (MCIC's) contain many "buried heat sources" in the form of resistors, capacitors, and inductors, the volume of which are increasing as well. Microelectronic packages and circuits and particularly high power microelectronics, require both temperature and temperature gradient control. The first primarily assures that the components are kept below a certain temperature threshold, providing reliability. Keeping the circuit between specific low and high temperature boundaries, primarily effects performance and structural considerations. Where other solutions are not available due to size, thermal load, or other systems considerations, a cold plate-a substrate equipped with liquid flow channels-could be resorted to. In most cases, however, the complexity that cold plates introduce, cannot be tolerated if for no reason other than cost. Heat exchange via a high thermal conductivity substrate connected to an appropriate heat sink must, in most cases, be relied on. Electrically conducting (metallic) substrates have become available but most applications require it to be a dielectric, exemplified by the most widely used "electronic" alumina (Al/sub 2/O/sub 3/, 96%) with an average thermal conductivity value of 20 W/mK. The last five years or so have seen an increase in the use of polycrystalline AlN (k/spl cong/175 W/mK). Its application has also been limited due to cost. Substrates based on yet another (polycrystalline) wide bandgap material, SiC (250 W/mK), are again too costly for most applications and are conductive. Furthermore, SiC occurs in several polymorphic forms and many polytypes i.e., it is hard to obtain phase pure, potentially causing property variations. SiC as well as diamond are available in single crystal thin film form and various quality (conductivity) grades. Commercially available polycrystalline thin film diamond ranges in TC value between 750 and 1500 W/mK. The as-deposited material displays a high surface roughness requiring, in most cases, extensive and thus expensive polishing to "planarize" it to receive the electronic circuitry.
{"title":"Wide bandgap materials in thermal management of electronic structures","authors":"P. Gielisse, H. Niculescu, J. Tremblay, S. Achmatowicz, M. Jakobowski, E. Zwierkowska, L. Golonka","doi":"10.1109/WBL.2001.946543","DOIUrl":"https://doi.org/10.1109/WBL.2001.946543","url":null,"abstract":"The need for optimized thermal management in microelectronic devices derives from several sources, of which the ever-increasing miniaturization is only one. Power dissipation needs in certain designs are up to 40 W/cm/sup 2/, while 100 W/cm/sup 2/ is said to be required in the not too distant future. New multilayer ceramic integrated circuits (MCIC's) contain many \"buried heat sources\" in the form of resistors, capacitors, and inductors, the volume of which are increasing as well. Microelectronic packages and circuits and particularly high power microelectronics, require both temperature and temperature gradient control. The first primarily assures that the components are kept below a certain temperature threshold, providing reliability. Keeping the circuit between specific low and high temperature boundaries, primarily effects performance and structural considerations. Where other solutions are not available due to size, thermal load, or other systems considerations, a cold plate-a substrate equipped with liquid flow channels-could be resorted to. In most cases, however, the complexity that cold plates introduce, cannot be tolerated if for no reason other than cost. Heat exchange via a high thermal conductivity substrate connected to an appropriate heat sink must, in most cases, be relied on. Electrically conducting (metallic) substrates have become available but most applications require it to be a dielectric, exemplified by the most widely used \"electronic\" alumina (Al/sub 2/O/sub 3/, 96%) with an average thermal conductivity value of 20 W/mK. The last five years or so have seen an increase in the use of polycrystalline AlN (k/spl cong/175 W/mK). Its application has also been limited due to cost. Substrates based on yet another (polycrystalline) wide bandgap material, SiC (250 W/mK), are again too costly for most applications and are conductive. Furthermore, SiC occurs in several polymorphic forms and many polytypes i.e., it is hard to obtain phase pure, potentially causing property variations. SiC as well as diamond are available in single crystal thin film form and various quality (conductivity) grades. Commercially available polycrystalline thin film diamond ranges in TC value between 750 and 1500 W/mK. The as-deposited material displays a high surface roughness requiring, in most cases, extensive and thus expensive polishing to \"planarize\" it to receive the electronic circuitry.","PeriodicalId":315832,"journal":{"name":"3rd International Conference 'Novel Applications of Wide Bandgap Layers' Abstract Book (Cat. No.01EX500)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129739458","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}
B. Walkowiak, W. Jakubowski, W. Okrój, V. Kochmanska, V. Króliczak
The use of medical implants allows one to improve patients lives, and quite often it can return patients back to normal activity in their personal and professional lives. One of the most difficult problems, which is necessary to solve, is a proper selection of the materials to be used for implant construction and/or implant coating. The surface of an implant is exposed to continuous contact with body fluids and several unwanted processes may occur there. Titanium and its alloys are generally accepted as the best tolerated materials for implants. But currently many efforts are focused on thin layers of crystalline carbon, i.e. diamond like carbon (DLC) and nanocrystalline diamond (NCD), used for coating of metal implants. This technology was successfully applied in bone surgery (screws), and more recently in heart surgery (stents). We found, with the fluorescence microscopy technique, that bacterial growth was possible on stainless steel, to a lesser degree on titanium, but NCD was almost totally resistant to bacterial colonization.
{"title":"Interaction of body fluids with carbon surfaces","authors":"B. Walkowiak, W. Jakubowski, W. Okrój, V. Kochmanska, V. Króliczak","doi":"10.1109/WBL.2001.946551","DOIUrl":"https://doi.org/10.1109/WBL.2001.946551","url":null,"abstract":"The use of medical implants allows one to improve patients lives, and quite often it can return patients back to normal activity in their personal and professional lives. One of the most difficult problems, which is necessary to solve, is a proper selection of the materials to be used for implant construction and/or implant coating. The surface of an implant is exposed to continuous contact with body fluids and several unwanted processes may occur there. Titanium and its alloys are generally accepted as the best tolerated materials for implants. But currently many efforts are focused on thin layers of crystalline carbon, i.e. diamond like carbon (DLC) and nanocrystalline diamond (NCD), used for coating of metal implants. This technology was successfully applied in bone surgery (screws), and more recently in heart surgery (stents). We found, with the fluorescence microscopy technique, that bacterial growth was possible on stainless steel, to a lesser degree on titanium, but NCD was almost totally resistant to bacterial colonization.","PeriodicalId":315832,"journal":{"name":"3rd International Conference 'Novel Applications of Wide Bandgap Layers' Abstract Book (Cat. No.01EX500)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127880441","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}
Hans-Erik Nilsson, Kent Bertilsson, E. Dubaric, M. Hjelm
Silicon Carbide is a very interesting semiconductor material for high temperature, high frequency, and high power applications. The main reasons are its high saturation velocity, large thermal conductivity, high Schottky barriers, and high breakdown voltages. High quality 4H-SiC and 6H-SiC polytype substrates and epitaxial layers are commercially available today. An additional advantage of SiC is the native oxide that allows fabrication of MOS devices. A large effort has been devoted towards the development of high performance devices in SiC. The largest success has been for unipolar devices like Schottky diodes and different kinds of MESFETs. MOSFETs have also been fabricated in both 4H- and 6H-SiC. Unfortunately, the MOSFET performance was found to be much worse than expected, due to a very low surface mobility. Nevertheless, the technology developed is very interesting and includes possible large scale integration of digital circuits operating at very high temperatures. In this work we present numerical simulations of the device performance of different Field Effect Transistors (FETs). Both full band Monte Carlo simulations and macroscopic modeling using the drift-diffusion approach have been utilized in this work. The Monte Carlo simulations have been used to extract transport parameters and to evaluate the macroscopic models in a device configuration.
{"title":"Numerical simulation of field effect transistors in 4H and 6H-SiC","authors":"Hans-Erik Nilsson, Kent Bertilsson, E. Dubaric, M. Hjelm","doi":"10.1106/152451102024432","DOIUrl":"https://doi.org/10.1106/152451102024432","url":null,"abstract":"Silicon Carbide is a very interesting semiconductor material for high temperature, high frequency, and high power applications. The main reasons are its high saturation velocity, large thermal conductivity, high Schottky barriers, and high breakdown voltages. High quality 4H-SiC and 6H-SiC polytype substrates and epitaxial layers are commercially available today. An additional advantage of SiC is the native oxide that allows fabrication of MOS devices. A large effort has been devoted towards the development of high performance devices in SiC. The largest success has been for unipolar devices like Schottky diodes and different kinds of MESFETs. MOSFETs have also been fabricated in both 4H- and 6H-SiC. Unfortunately, the MOSFET performance was found to be much worse than expected, due to a very low surface mobility. Nevertheless, the technology developed is very interesting and includes possible large scale integration of digital circuits operating at very high temperatures. In this work we present numerical simulations of the device performance of different Field Effect Transistors (FETs). Both full band Monte Carlo simulations and macroscopic modeling using the drift-diffusion approach have been utilized in this work. The Monte Carlo simulations have been used to extract transport parameters and to evaluate the macroscopic models in a device configuration.","PeriodicalId":315832,"journal":{"name":"3rd International Conference 'Novel Applications of Wide Bandgap Layers' Abstract Book (Cat. No.01EX500)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122418419","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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