Pub Date : 1998-10-19DOI: 10.1109/IWCE.1998.742714
B. Eisenberg
Ionic channels are proteins with a hole down their middle, natural nanotubes of great biological importance because they regulate many activities of cells in health and disease. Ionic channels have simple structure and obey the familiar drift-diffusion equations of semiconductor physics. It seems likely that higher resolution theories of computational electronics (e.g., Monte Carlo simulations) will reveal even more about how channels, and perhaps other proteins, function. Thus, the study of channels is a promising area for interdisciplinary investigation.
{"title":"Ionic channels in biological membranes: natural nanotubes described by the drift-diffusion equations","authors":"B. Eisenberg","doi":"10.1109/IWCE.1998.742714","DOIUrl":"https://doi.org/10.1109/IWCE.1998.742714","url":null,"abstract":"Ionic channels are proteins with a hole down their middle, natural nanotubes of great biological importance because they regulate many activities of cells in health and disease. Ionic channels have simple structure and obey the familiar drift-diffusion equations of semiconductor physics. It seems likely that higher resolution theories of computational electronics (e.g., Monte Carlo simulations) will reveal even more about how channels, and perhaps other proteins, function. Thus, the study of channels is a promising area for interdisciplinary investigation.","PeriodicalId":357304,"journal":{"name":"1998 Sixth International Workshop on Computational Electronics. Extended Abstracts (Cat. No.98EX116)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129260899","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 : 1998-10-19DOI: 10.1109/IWCE.1998.742760
D. Vasileska, W. J. Gross, D. Ferry
The authors present simulation results for the subthreshold characteristics of n-channel MOSFETs with 0.1 /spl mu/m gate-length and 0.05 /spl mu/m gate-width obtained with our 3D-DD simulator. We also presented a new method that one can successfully use in a particle-based simulator to properly account for the short-range portions of the e-e and e-i interactions without double-counting the long-range portions of these two interaction terms.
{"title":"Modeling of deep-submicrometer MOSFETs: random impurity effects, threshold voltage shifts and gate capacitance attenuation","authors":"D. Vasileska, W. J. Gross, D. Ferry","doi":"10.1109/IWCE.1998.742760","DOIUrl":"https://doi.org/10.1109/IWCE.1998.742760","url":null,"abstract":"The authors present simulation results for the subthreshold characteristics of n-channel MOSFETs with 0.1 /spl mu/m gate-length and 0.05 /spl mu/m gate-width obtained with our 3D-DD simulator. We also presented a new method that one can successfully use in a particle-based simulator to properly account for the short-range portions of the e-e and e-i interactions without double-counting the long-range portions of these two interaction terms.","PeriodicalId":357304,"journal":{"name":"1998 Sixth International Workshop on Computational Electronics. Extended Abstracts (Cat. No.98EX116)","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115684344","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 : 1998-10-19DOI: 10.1109/IWCE.1998.742722
Y. Kamakura, K. Taniguchi
High-energy hole scattering rates for a full band Monte Carlo simulation in Si are verified using the quantum yield experiment. We compare two models that yield the correct velocity-field and ionization coefficient characteristics but quite different energy distributions. It is demonstrated that the quantum yield experiment is available as a new monitor of hole scattering rates in Si: the model based on ab initio impact ionization rate shows good agreement with the experiments.
{"title":"Verification of hole scattering rates in Si with quantum yield experiment","authors":"Y. Kamakura, K. Taniguchi","doi":"10.1109/IWCE.1998.742722","DOIUrl":"https://doi.org/10.1109/IWCE.1998.742722","url":null,"abstract":"High-energy hole scattering rates for a full band Monte Carlo simulation in Si are verified using the quantum yield experiment. We compare two models that yield the correct velocity-field and ionization coefficient characteristics but quite different energy distributions. It is demonstrated that the quantum yield experiment is available as a new monitor of hole scattering rates in Si: the model based on ab initio impact ionization rate shows good agreement with the experiments.","PeriodicalId":357304,"journal":{"name":"1998 Sixth International Workshop on Computational Electronics. Extended Abstracts (Cat. No.98EX116)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114962550","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 : 1998-10-19DOI: 10.1109/IWCE.1998.742693
C. Jacoboni, A. Bertoni, P. Bordone, R. Brunetti
A Wigner-function approach to the study of quantum transport in open systems in the presence of phonon scattering is presented. Two important issues are discussed: a) the existence of Wigner paths in phase space with many analogies with the semiclassical description of transport and b) how to deal with boundary conditions for the analysis of real open structures. Theoretical and computational results are discussed in view of the application of this formalism to the simulation of transport in mesoscopic structures.
{"title":"Wigner paths and boundary conditions for electron transport in open systems with electron-phonon interaction","authors":"C. Jacoboni, A. Bertoni, P. Bordone, R. Brunetti","doi":"10.1109/IWCE.1998.742693","DOIUrl":"https://doi.org/10.1109/IWCE.1998.742693","url":null,"abstract":"A Wigner-function approach to the study of quantum transport in open systems in the presence of phonon scattering is presented. Two important issues are discussed: a) the existence of Wigner paths in phase space with many analogies with the semiclassical description of transport and b) how to deal with boundary conditions for the analysis of real open structures. Theoretical and computational results are discussed in view of the application of this formalism to the simulation of transport in mesoscopic structures.","PeriodicalId":357304,"journal":{"name":"1998 Sixth International Workshop on Computational Electronics. Extended Abstracts (Cat. No.98EX116)","volume":"8 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114028941","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 : 1998-10-19DOI: 10.1109/IWCE.1998.742703
Géza Tóth, J. Timler, C. Lent
A coherence vector formalism is used to describe quantum computing with quantum-dot cellular automata, and the realizations of basic quantum gates are also discussed.
用相干向量的形式描述了量子点元胞自动机的量子计算，并讨论了基本量子门的实现。
{"title":"Quantum computing with quantum-dot cellular automata using coherence vector formalism","authors":"Géza Tóth, J. Timler, C. Lent","doi":"10.1109/IWCE.1998.742703","DOIUrl":"https://doi.org/10.1109/IWCE.1998.742703","url":null,"abstract":"A coherence vector formalism is used to describe quantum computing with quantum-dot cellular automata, and the realizations of basic quantum gates are also discussed.","PeriodicalId":357304,"journal":{"name":"1998 Sixth International Workshop on Computational Electronics. Extended Abstracts (Cat. No.98EX116)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130770324","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 : 1998-10-19DOI: 10.1109/IWCE.1998.742741
S. Babiker, A. Asenov, S. Roy, J. Barker, S. Beaumont
The impact of In/sub x/Al/sub 1-x/As strain control buffers on the performance of low In content InGaAs channel pseudomorphic high electron mobility transistor p(HEMT) is investigated. It is shown that relaxed and tensile strained channel devices outperform the conventional compressively strained channel devices. It is argued that strain engineering in GaAs based devices makes it possible to realise RF characteristics comparable to InP based pHEMTs while obtaining improved breakdown characteristics.
{"title":"Strain engineered In/sub x/Ga/sub 1-x/As channel pHEMTs on virtual substrates: a simulation study","authors":"S. Babiker, A. Asenov, S. Roy, J. Barker, S. Beaumont","doi":"10.1109/IWCE.1998.742741","DOIUrl":"https://doi.org/10.1109/IWCE.1998.742741","url":null,"abstract":"The impact of In/sub x/Al/sub 1-x/As strain control buffers on the performance of low In content InGaAs channel pseudomorphic high electron mobility transistor p(HEMT) is investigated. It is shown that relaxed and tensile strained channel devices outperform the conventional compressively strained channel devices. It is argued that strain engineering in GaAs based devices makes it possible to realise RF characteristics comparable to InP based pHEMTs while obtaining improved breakdown characteristics.","PeriodicalId":357304,"journal":{"name":"1998 Sixth International Workshop on Computational Electronics. Extended Abstracts (Cat. No.98EX116)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130902474","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 : 1998-10-19DOI: 10.1109/IWCE.1998.742762
K. Matsuzawa, Y. Oowaki, M. Nakamura, N. Aoki, I. Mizushima
We investigate the propriety of SCM (scanning capacitance microscopy) for determination of impurity distribution of MOSFETs. Two-dimensional impurity distribution is converted from /spl Delta/C//spl Delta/V signal obtained by SCM. It is revealed that the SCM signal is quite sensitive to the effects of charge depletion around the pn junction, singularity of structure in vicinity of SiO/sub 2//Si interface (edge effect), and the work function of the gate electrode. Making use of process/device simulations to analyze these effects, it is found that the SCM signal near the channel surface region of the Si substrate contains large error due to the edge effects. The lateral extent of the source/drain region obtained by SCM shows reasonable agreement with that determined by measurements and simulations of electrical characteristics of the MOSFET.
{"title":"Simulation analysis of impurity profile extraction by SCM","authors":"K. Matsuzawa, Y. Oowaki, M. Nakamura, N. Aoki, I. Mizushima","doi":"10.1109/IWCE.1998.742762","DOIUrl":"https://doi.org/10.1109/IWCE.1998.742762","url":null,"abstract":"We investigate the propriety of SCM (scanning capacitance microscopy) for determination of impurity distribution of MOSFETs. Two-dimensional impurity distribution is converted from /spl Delta/C//spl Delta/V signal obtained by SCM. It is revealed that the SCM signal is quite sensitive to the effects of charge depletion around the pn junction, singularity of structure in vicinity of SiO/sub 2//Si interface (edge effect), and the work function of the gate electrode. Making use of process/device simulations to analyze these effects, it is found that the SCM signal near the channel surface region of the Si substrate contains large error due to the edge effects. The lateral extent of the source/drain region obtained by SCM shows reasonable agreement with that determined by measurements and simulations of electrical characteristics of the MOSFET.","PeriodicalId":357304,"journal":{"name":"1998 Sixth International Workshop on Computational Electronics. Extended Abstracts (Cat. No.98EX116)","volume":"54 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114253977","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 : 1998-10-19DOI: 10.1109/IWCE.1998.742744
T. Maruizumi, Y. Takemura, J. Ushio, M. Miyao
We have extended the two-dimensional deposition simulator with a micrometer feature scale based on the ballistic transport and reaction model originally developed by Cale et al. (1993) to include a scheme to inhibit and/or accelerate the deposition reaction stemming from the product gases. We have also improved the algorithm used to calculate a self-consistent gas flux distribution on micro features at each step in the simulation. Application of this deposition simulator to seven CVD systems for ULSI usage showed good agreement between the calculated and experimental feature profiles. The validity of the reactive sticking coefficient's role as a general descriptor for step coverage characteristics was thoroughly examined using these simulated results and we concluded that the intrinsic reaction mechanism is more reliable than the sticking coefficient for all CVD characteristics. Molecular orbital calculation was also demonstrated to be extremely helpful in clarifying the intrinsic deposition mechanism.
{"title":"Two-dimensional CVD profile simulator based on ballistic transport and reaction model","authors":"T. Maruizumi, Y. Takemura, J. Ushio, M. Miyao","doi":"10.1109/IWCE.1998.742744","DOIUrl":"https://doi.org/10.1109/IWCE.1998.742744","url":null,"abstract":"We have extended the two-dimensional deposition simulator with a micrometer feature scale based on the ballistic transport and reaction model originally developed by Cale et al. (1993) to include a scheme to inhibit and/or accelerate the deposition reaction stemming from the product gases. We have also improved the algorithm used to calculate a self-consistent gas flux distribution on micro features at each step in the simulation. Application of this deposition simulator to seven CVD systems for ULSI usage showed good agreement between the calculated and experimental feature profiles. The validity of the reactive sticking coefficient's role as a general descriptor for step coverage characteristics was thoroughly examined using these simulated results and we concluded that the intrinsic reaction mechanism is more reliable than the sticking coefficient for all CVD characteristics. Molecular orbital calculation was also demonstrated to be extremely helpful in clarifying the intrinsic deposition mechanism.","PeriodicalId":357304,"journal":{"name":"1998 Sixth International Workshop on Computational Electronics. Extended Abstracts (Cat. No.98EX116)","volume":"121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115631144","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 : 1998-10-19DOI: 10.1109/IWCE.1998.742699
M. Stopa
We have performed spin density functional theory calculations to determine the electronic structure of lateral GaAs-AlGaAs quantum dots. We have developed a highly efficient, quasi-adiabatic subband method which allows us to solve the Schrodinger equation for dot electron number N/spl lsim/200. We find that the direct Coulomb energy of putting two electrons into up and down spin of the same spatial state at the Fermi surface, combined with the polarization dependent, exchange-correlation induced splitting of the spin levels, typically exceeds the average single particle level spacing and leads to spontaneous spin polarization of the dot.
{"title":"Spontaneous polarization of quantum dots","authors":"M. Stopa","doi":"10.1109/IWCE.1998.742699","DOIUrl":"https://doi.org/10.1109/IWCE.1998.742699","url":null,"abstract":"We have performed spin density functional theory calculations to determine the electronic structure of lateral GaAs-AlGaAs quantum dots. We have developed a highly efficient, quasi-adiabatic subband method which allows us to solve the Schrodinger equation for dot electron number N/spl lsim/200. We find that the direct Coulomb energy of putting two electrons into up and down spin of the same spatial state at the Fermi surface, combined with the polarization dependent, exchange-correlation induced splitting of the spin levels, typically exceeds the average single particle level spacing and leads to spontaneous spin polarization of the dot.","PeriodicalId":357304,"journal":{"name":"1998 Sixth International Workshop on Computational Electronics. Extended Abstracts (Cat. No.98EX116)","volume":"214 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116160940","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 : 1998-10-19DOI: 10.1109/IWCE.1998.742734
M. Ogawa, T. Sugano, T. Miyoshi
We report on calculations of quantum transport in an InAs/GaSb/AlSb (type II) based double barrier resonant tunneling diode. Our procedure uses a realistic band structure based on an empirical tight binding theory. In the formulation, an evanescent-wave matching at heterointerfaces as well as the conduction and valence-band-mixing effects, and the space charge effect are duly taken into account. Comparison has been made between our results and calculations using a two-band model which considers only the lowest conduction and the light-hole states. Our results show that current-voltage characteristics have an extra current peak due to significant heavy-hole mixing effects in the GaSb quantum well. It should be also noted that the matching of evanescent electron modes is essentially necessary to include the valley-mixing effects for the heterostructures, since breaking of a lattice-translational symmetry occurs at the interfaces.
{"title":"Tight binding simulation of quantum electron transport in type II resonant tunneling devices","authors":"M. Ogawa, T. Sugano, T. Miyoshi","doi":"10.1109/IWCE.1998.742734","DOIUrl":"https://doi.org/10.1109/IWCE.1998.742734","url":null,"abstract":"We report on calculations of quantum transport in an InAs/GaSb/AlSb (type II) based double barrier resonant tunneling diode. Our procedure uses a realistic band structure based on an empirical tight binding theory. In the formulation, an evanescent-wave matching at heterointerfaces as well as the conduction and valence-band-mixing effects, and the space charge effect are duly taken into account. Comparison has been made between our results and calculations using a two-band model which considers only the lowest conduction and the light-hole states. Our results show that current-voltage characteristics have an extra current peak due to significant heavy-hole mixing effects in the GaSb quantum well. It should be also noted that the matching of evanescent electron modes is essentially necessary to include the valley-mixing effects for the heterostructures, since breaking of a lattice-translational symmetry occurs at the interfaces.","PeriodicalId":357304,"journal":{"name":"1998 Sixth International Workshop on Computational Electronics. Extended Abstracts (Cat. No.98EX116)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121456448","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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