Pub Date : 2009-05-27DOI: 10.1109/IWCE.2009.5091108
I. M. Tienda-Luna, F. Ruiz, A. Godoy, F. Gámiz
A variety of techniques can be employed to increase the drive current in CMOS transistors. In this paper, we study the effects of using different wafer orientations and strain methods in surrounding gate transistors. Specifically, we focus on Quantum Electron Density and mobility. A significant modification of both magnitudes is to be expected, due to the changes caused in the effective mass tensor and in the conduction band edge position.
{"title":"Effect of Arbitrary Orientation and Strain on Surrounding Gate Transistors","authors":"I. M. Tienda-Luna, F. Ruiz, A. Godoy, F. Gámiz","doi":"10.1109/IWCE.2009.5091108","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091108","url":null,"abstract":"A variety of techniques can be employed to increase the drive current in CMOS transistors. In this paper, we study the effects of using different wafer orientations and strain methods in surrounding gate transistors. Specifically, we focus on Quantum Electron Density and mobility. A significant modification of both magnitudes is to be expected, due to the changes caused in the effective mass tensor and in the conduction band edge position.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116778711","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 : 2009-05-27DOI: 10.1109/IWCE.2009.5091091
Yu He, Jinyu Zhang, Ming Zhang, Yan Wang, Zhiping Yu
We investigate both end-contact and side-contact structures between Al, Pd, Sc and carbon nanotube (CNT) in this paper. The different structures show the different chemical bonds and charge transfer at the metal-CNT contact interfaces. A novel method based on dipole effect is proposed to calculate the Schottky barrier height (SBH). Different SBHs for the contacts are due to different electro-negativity of metal atoms as well as the chemical bonds.
{"title":"Chemical Bonding and Schottky Barrier for Metal-Carbon Nanotube Contacts","authors":"Yu He, Jinyu Zhang, Ming Zhang, Yan Wang, Zhiping Yu","doi":"10.1109/IWCE.2009.5091091","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091091","url":null,"abstract":"We investigate both end-contact and side-contact structures between Al, Pd, Sc and carbon nanotube (CNT) in this paper. The different structures show the different chemical bonds and charge transfer at the metal-CNT contact interfaces. A novel method based on dipole effect is proposed to calculate the Schottky barrier height (SBH). Different SBHs for the contacts are due to different electro-negativity of metal atoms as well as the chemical bonds.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131753332","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 : 2009-05-27DOI: 10.1109/IWCE.2009.5091082
H. Ryu, Sunhee Lee, Gerhard Klimeck
A highly phosphorus delta-doped Si device is modeled with a quantum well with periodic boundary conditions and the semi-empirical spds* tight-binding band model. Its temperature-dependent electronic properties are studied. To account for high doping density with many electrons, a highly parallelized self-consistent Schrodinger-Poisson solver is used with atomistic representations of multiple impurity ions. The band-structure in equilibrium and the corresponding Fermi-level position are computed for a selective set of temperatures. The result at room temperature is compared with previous studies and the temperature-dependent electronic properties are discussed further in detail with the calculated 3-D self-consistent potential profile.
{"title":"A Study of Temperature-dependent Properties of N-type d-doped Si Band-structures in Equilibrium","authors":"H. Ryu, Sunhee Lee, Gerhard Klimeck","doi":"10.1109/IWCE.2009.5091082","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091082","url":null,"abstract":"A highly phosphorus delta-doped Si device is modeled with a quantum well with periodic boundary conditions and the semi-empirical spds* tight-binding band model. Its temperature-dependent electronic properties are studied. To account for high doping density with many electrons, a highly parallelized self-consistent Schrodinger-Poisson solver is used with atomistic representations of multiple impurity ions. The band-structure in equilibrium and the corresponding Fermi-level position are computed for a selective set of temperatures. The result at room temperature is compared with previous studies and the temperature-dependent electronic properties are discussed further in detail with the calculated 3-D self-consistent potential profile.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127855034","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 : 2009-05-27DOI: 10.1109/IWCE.2009.5091157
D. Fu, Rong Zhang, B. Liu, Z. Xie, X. Xiu, Hai Lu, Youdou Zheng, G. Edwards
In this paper, the k- p perturbation theory is adopted to calculate the interband excitonic transition energies and their polarization selection rules in c-plane A1N films, Ga x Al 1-x N and In x Al 1-x N alloys modulated by both isotropic biaxial in-plane strain and alloy compositions. It is shown that valence band mixing induced by both strain and alloy composition has dramatic influence on the optical polarization properties. The calculated results provide both good physical insight into the band structure engineering and helpful instructions in the future design of high efficient and novel UV-emitters.
本文采用k- p摄动理论计算了各向同性双轴面内应变和合金成分调制的c面A1N薄膜、Ga x Al 1-x N和In x Al 1-x N合金带间激子跃迁能及其极化选择规律。结果表明，由应变和合金成分引起的价带混合对光学偏振性能有显著影响。计算结果为波段结构工程提供了良好的物理见解，并为今后设计高效新型紫外发射体提供了有益的指导。
{"title":"Strain- and Compositional Modulation of the Near-Band-Edge Band Structures of AlN and Its Ternary Alloys with GaN and InN","authors":"D. Fu, Rong Zhang, B. Liu, Z. Xie, X. Xiu, Hai Lu, Youdou Zheng, G. Edwards","doi":"10.1109/IWCE.2009.5091157","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091157","url":null,"abstract":"In this paper, the k- p perturbation theory is adopted to calculate the interband excitonic transition energies and their polarization selection rules in c-plane A1N films, Ga x Al 1-x N and In x Al 1-x N alloys modulated by both isotropic biaxial in-plane strain and alloy compositions. It is shown that valence band mixing induced by both strain and alloy composition has dramatic influence on the optical polarization properties. The calculated results provide both good physical insight into the band structure engineering and helpful instructions in the future design of high efficient and novel UV-emitters.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121392222","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 : 2009-05-27DOI: 10.1109/IWCE.2009.5091149
S. Souma, M. Ogawa, Takahiro Yamamoto, Kazuyuki Watanabe
We study the spin filtering characteristics of the zigzag-edged graphene nanoribbon spin filtering device, applying the spin-density functional tight-binding method and the non- equilibrium Green's function method. Our simulations have shown that the spin filtering effect can be controlled by applying the side-gate voltages that effectively induce the transverse electric fields. Influence of an edge lattice vacancy on the spin- filtering effect is also discussed.
{"title":"Simulation of Graphene Nanoribbon Spin-Filter Device with Spin-Density Functional Tight-Binding Method","authors":"S. Souma, M. Ogawa, Takahiro Yamamoto, Kazuyuki Watanabe","doi":"10.1109/IWCE.2009.5091149","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091149","url":null,"abstract":"We study the spin filtering characteristics of the zigzag-edged graphene nanoribbon spin filtering device, applying the spin-density functional tight-binding method and the non- equilibrium Green's function method. Our simulations have shown that the spin filtering effect can be controlled by applying the side-gate voltages that effectively induce the transverse electric fields. Influence of an edge lattice vacancy on the spin- filtering effect is also discussed.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125979029","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 : 2009-05-27DOI: 10.1109/IWCE.2009.5091116
M. Bescond, M. Lannoo, L. Raymond, F. Michelini, M. Pala
This study presents ionized impurity impacts on silicon nanowire MOS transistors. We first calculate the current characteristics with a self-consistent three-dimensional (3D) Green's function approach and show the effects of both acceptor and donor impurities on the physical electron properties. In particular, we emphasize that the presence of a donor induces different transport phenomena according to the applied gate bias. Considering an attractive Coulomb potential, we then evaluate the effective mass validity by comparing the localized states of cubic dots with those obtained through a sp 3 third-neighbor tight-binding model. Our results show that in first approximation, the effective mass is still adapted to treat ionized impurities.
{"title":"Influence of Ionized Impurities in Silicon Nanowire MOS Transistors","authors":"M. Bescond, M. Lannoo, L. Raymond, F. Michelini, M. Pala","doi":"10.1109/IWCE.2009.5091116","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091116","url":null,"abstract":"This study presents ionized impurity impacts on silicon nanowire MOS transistors. We first calculate the current characteristics with a self-consistent three-dimensional (3D) Green's function approach and show the effects of both acceptor and donor impurities on the physical electron properties. In particular, we emphasize that the presence of a donor induces different transport phenomena according to the applied gate bias. Considering an attractive Coulomb potential, we then evaluate the effective mass validity by comparing the localized states of cubic dots with those obtained through a sp 3 third-neighbor tight-binding model. Our results show that in first approximation, the effective mass is still adapted to treat ionized impurities.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"06 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128241384","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 : 2009-05-27DOI: 10.1109/IWCE.2009.5091140
M. Usman, H. Ryu, Sunhee Lee, Y. H. Tan, Gerhard Klimeck
The atomistic tight binding simulator NEMO 3-D has previously been validated against the experimental data for quantum dots, wells, and wires in the InGaAlAs and SiGe material systems. Here, we demonstrate our new capability to compute optical matrix elements and transition strengths in tight binding. Systematic multi-million atom electronic structure calculations explore the quantum confined stark shift and the ground state optical transition rate for an electric field in the lateral (100) direction. The simulations treat the strain in a ~15 million atom system and the electronic structure in a subset of ~9 million atoms. The effects of the long range strain, the optical polarization anisotropy, the interface roughness, and the non- degeneracy of the p-states which are missing in continuum methods like effective mass approximation or kp are included. A significant red shift in the emission spectra due to an applied in- plane electric field indicating a strong quantum confined stark effect (QSCE) is observed. The ground state optical transition rate rapidly decreases with the increasing electric field magnitude due to reduced spatial overlap of ground electron and hole states.
{"title":"Quantum Confined Stark Shift and Ground State Optical Transition Rate in [100] Laterally Biased InAs/GaAs Quantum Dots","authors":"M. Usman, H. Ryu, Sunhee Lee, Y. H. Tan, Gerhard Klimeck","doi":"10.1109/IWCE.2009.5091140","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091140","url":null,"abstract":"The atomistic tight binding simulator NEMO 3-D has previously been validated against the experimental data for quantum dots, wells, and wires in the InGaAlAs and SiGe material systems. Here, we demonstrate our new capability to compute optical matrix elements and transition strengths in tight binding. Systematic multi-million atom electronic structure calculations explore the quantum confined stark shift and the ground state optical transition rate for an electric field in the lateral (100) direction. The simulations treat the strain in a ~15 million atom system and the electronic structure in a subset of ~9 million atoms. The effects of the long range strain, the optical polarization anisotropy, the interface roughness, and the non- degeneracy of the p-states which are missing in continuum methods like effective mass approximation or kp are included. A significant red shift in the emission spectra due to an applied in- plane electric field indicating a strong quantum confined stark effect (QSCE) is observed. The ground state optical transition rate rapidly decreases with the increasing electric field magnitude due to reduced spatial overlap of ground electron and hole states.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130374232","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 : 2009-05-27DOI: 10.1109/IWCE.2009.5091127
M. Shin
We have developed a full quantum transport simulator for nanowire field effect transistors based on the eight- band k ldr p Hamiltonian. The NEGF formalism was employed for transport calculation and the self-consistent calculations were performed. We were able to reduce the size of the Hamiltonian greatly by performing the mode-space transformation followed by selecting a small number of modes contributing to the transport. This, together with the approximate but highly accurate solutions of cross-section wave-functions, enabled us to carry out the transport calculation very efficiently. In this work, we demonstrate the capability of our simulator by showing the hole transport in PMOS Si nanowire transistors and the band-to-band tunneling in InAs nanowire transistors.
{"title":"NEGF Simulation of Nanowire Field Effect Transistors Using the Eight-band k · p method","authors":"M. Shin","doi":"10.1109/IWCE.2009.5091127","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091127","url":null,"abstract":"We have developed a full quantum transport simulator for nanowire field effect transistors based on the eight- band k ldr p Hamiltonian. The NEGF formalism was employed for transport calculation and the self-consistent calculations were performed. We were able to reduce the size of the Hamiltonian greatly by performing the mode-space transformation followed by selecting a small number of modes contributing to the transport. This, together with the approximate but highly accurate solutions of cross-section wave-functions, enabled us to carry out the transport calculation very efficiently. In this work, we demonstrate the capability of our simulator by showing the hole transport in PMOS Si nanowire transistors and the band-to-band tunneling in InAs nanowire transistors.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131017015","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 : 2009-05-27DOI: 10.1109/IWCE.2009.5091083
Gerhard Klimeck, D. Vasileska
← ← Abstract — The ABACUS and AQME on-line tools and their associated wiki pages form one-stop shops for educators and students of existing university courses. They are geared towards courses like "introduction to Semiconductor Devices" and "Quantum Mechanics for Engineers". The service is free to anyone and no software installation is required on the user's computer. All simulations, including advanced visualization are performed at a remote computer. The tools have been deployed on nanoHUB.org in August 2008 and haven already been used by over 700 users. This paper describes nanoHUB educational tool user requirements and the motivation for and some details about these new tools. Usage patterns and future planned assessment are discussed. The concepts of "NCN supported" and "Community Supported" tools are discussed.
{"title":"ABACUS and AQME: Semiconductor Device and Quantum Mechanics Education on nanoHUB.org","authors":"Gerhard Klimeck, D. Vasileska","doi":"10.1109/IWCE.2009.5091083","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091083","url":null,"abstract":"← ← Abstract — The ABACUS and AQME on-line tools and their associated wiki pages form one-stop shops for educators and students of existing university courses. They are geared towards courses like \"introduction to Semiconductor Devices\" and \"Quantum Mechanics for Engineers\". The service is free to anyone and no software installation is required on the user's computer. All simulations, including advanced visualization are performed at a remote computer. The tools have been deployed on nanoHUB.org in August 2008 and haven already been used by over 700 users. This paper describes nanoHUB educational tool user requirements and the motivation for and some details about these new tools. Usage patterns and future planned assessment are discussed. The concepts of \"NCN supported\" and \"Community Supported\" tools are discussed.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133307887","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：