{"title":"Numerical Simulation of Plasma Waves in High-Electron-Mobility Transistors Using Kinetic Transport Model","authors":"A. Satou, V. Ryzhii, N. Vagidov, V. Mitin","doi":"10.1109/IWCE.2009.5091133","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091133","url":null,"abstract":"We study plasma waves in a high-electron-mobility transistor (HEMT) structure by numerical simulation using the kinetic electron transport model. We find that the plasma waves in the gated section of the channel can damp even without the electron collisions with impurities and phonons. The damping is related to the thermal spread of the electron velocity. We also show that the ungated sections of the channel play an important role in determining the plasma frequency and the damping rate because the plasma waves spread over the entire channel.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"32 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":"133006282","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}
{"title":"Electrical Transport through Single DNA Molecules by Distinct Tip-Surface Configurations","authors":"Jun Qian, S. Liao, M. Stroscio, M. Dutta, Song Xu","doi":"10.1109/IWCE.2009.5091111","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091111","url":null,"abstract":"In this paper, gold-DNA-gold nanoparticle (GNP) complexes were studied by scanning tunneling microscopy (STM). I-V characteristics were collected from distinct positions of gold nanoparticle clusters and qualitatively explained by a tip- surface configuration model. Double-stranded DNA (dsDNA) of poly(dT)-poly(dA) was found to be slightly n-type semiconductor by theoretical simulation of the S-shaped I-V curves employing the Landauer formalism.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"273 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":"116552920","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}
{"title":"Mode Decomposition Techniques for Electronic Structure Calculations of 3D Nanowire Devices","authors":"D. Zhang, E. Polizzi","doi":"10.1109/IWCE.2009.5091119","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091119","url":null,"abstract":"In order to address the high numerical cost for computing the electron density of large-scale atomistic nanowire devices, we investigate the relevance of mode decomposition techniques (i.e. mode approach) for solving the Schrodinger-type equation within a real-space mesh framework. It is shown how the full mode approach or its asymptotic counterpart can be of benefit to two distinct highly efficient numerical procedures for computing the electron density: (i) the CMB strategy and (ii) the FEAST algorithm. Finally, numerical simulation examples of carbon nanotubes are presented to highlight the effects of finite dimension on the density of states.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"128 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":"121945948","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}
{"title":"Device Performance of Graphene Nanoribbon Field Effect Transistors with Edge Roughness Effects: A Computational Study","authors":"Z. Leong, K. Lam, G. Liang","doi":"10.1109/IWCE.2009.5091104","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091104","url":null,"abstract":"The device performance of armchair edge graphene nanoribbon Schottky barrier field effect transistors (A-GNR SBFETs) over different edge roughness and widths are investigated over a wide range of devices in terms of I ON /I OFF . Generally, wider GNRs outperform narrower GNRs in the presence of edge roughness effects with average leakage current reduced up to ~400% less. The average leakage current for 2.2 nm width GNR SBFETs increased 2.7 times when edge roughness increased from 5% to 10%, while the same for 1.4 nm widths increased 11.2 times In addition, a small amount of ER of 5% is well tolerated by all GNR SBFETs, with the average I ON /I OFF lowered from 4012 to 3075 for 1.4 nm widths. However, a further increase in ER to 20% degrades performance greatly, dropping I ON /I OFF to 273. The generally reliable performance of GNR SBFETs at small edge irregularities over channel widths is reported and a detailed statistical investigation provided.","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":"127561771","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}
{"title":"CNT Research: from Academic Wonder to Industrial Exploration","authors":"S. Fan","doi":"10.1109/IWCE.2009.5091094","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091094","url":null,"abstract":"Carbon nanotubes (CNT) are nano-scale tubular structures which consist of seamless cylindrical shells of graphitic sheets. They were first found by professor Sumio Iijima in the arcdischarge soot between graphite electrodes in 1991 [1]. As a newly discovered carbon allotrope, CNTs have drawn worldwide attentions by their unique electrical, mechanical, and thermal properties. Seven years after their discovery, CNTs were synthesized in the form of arrays by chemical vapor deposition (CVD) [2,3]. For the first time in the history, billions of CNTs were aligned in the vertical direction on a substrate, and their growth position can be controlled by catalyst pattern design [3]. In 2002, we discovered a new type of CNT array, which is named the super-aligned CNT array. This kind of array was composed of clean, straight and defectfree CNTs, and there exist strong Van de Waals forces between adjacent nanotubes. Due to this unique feature, when one picks a strand of CNTs by tweezers or adhesive tapes, continuous long yarns or films can be simply pulled out from the array [4], as shown in figure 1. This discovery had enabled us to produce macroscopic materials with pure CNTs with a quick and easy dry spin process, as shown in figure 2. In 2005, we scaled up the substrate size of the CNT arrays from 1 inch to 4 inches, which could provide CNT films as wide as 10 cm [5]. Figure 1. The mechanism of dry spinning CNT yarns and films from super-aligned CNT arrays. The CNT yarns and films are composed of sparse parallel CNTs along the pulling direction. With the large percent of the vacancy between CNTs, the as drawn films can have transparency up to 90%. Therefore, CNT films can be used as a new type of transparent conductive film which have potential applications in liquid crystal displays and touch panels. The CNT films also have superb flexibility which is desired in flexible IT products. Figure 2. a) Spinning CNT film. b) A SEM image of the CNT film. c) A CNT film shrink into a fiber when passing through a drop of ethanol. d) A SEM image of the CNT fiber.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"119 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":"127596312","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}
{"title":"Optimization Algorithms for Josephson Qubits","authors":"R. Roloff, M. Wenin, Walter Pötz","doi":"10.1109/IWCE.2009.5091135","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091135","url":null,"abstract":"Superconducting nanoelectrical circuits are promising candidates for the physical implementation of the basic building block of a quantum computer, the qubit. We investigate how optimal control theory can be applied to optimize the dynamics of Josephson qubits. For the example of the charge qubit, several numerical methods are employed to search for external control fields which, by current technology, are realistic and induce the desired unitary time evolution within the system (i.e. the desired gate operation) as faithfully as possible in presence of dissipation, decoherence and leakage. Associated calculations which model the environment microscopically are time-intensive so that parallel computing methods are beneficial in the sampling over control fields. In particular, we discuss the performance of differential-evolution-algorithm based optimizations on a cluster. Using a simpler Lindblad model for environmental effects, we compare the performance of a conjugate-gradient approach to that of a genetic algorithm.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"4 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":"124460021","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}
{"title":"Numerical Quadrature of the Subband Distribution Functions in Strained Silicon UTB Devices","authors":"O. Baumgartner, M. Karner, V. Sverdlov, H. Kosina","doi":"10.1109/IWCE.2009.5091131","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091131","url":null,"abstract":"In this work, the kldrp method is used to calculate the electronic subband structure. To reduce the computational cost of the carrier concentration calculation and henceforth the required number of numerical solutions of the Schrodinger equation, an efficient 2D k-space integration by means of the Clenshaw-Curtis method is proposed. The suitability of our approach is demonstrated by simulation results of Si UTB double gate nMOS and pMOS devices.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"14 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":"121301247","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}
Noelia Fuentes, A. Parra, Enrique Oltra, J. Cuerva, S. Rodríguez-Bolívar, F. Gómez-Campos, J. A. López-Villanueva, J. E. Carceller, E. Buñuel, D. Cárdenas
{"title":"Computational Study of a Nanofuse Based on Organic Molecules","authors":"Noelia Fuentes, A. Parra, Enrique Oltra, J. Cuerva, S. Rodríguez-Bolívar, F. Gómez-Campos, J. A. López-Villanueva, J. E. Carceller, E. Buñuel, D. Cárdenas","doi":"10.1109/IWCE.2009.5091096","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091096","url":null,"abstract":"Molecular electronics might be a solution for the challenges raised in the context of the Moore's law for the following years. In this paper we present a computational study simulating the electronic behavior of a new generation of molecular switches with excellent geometrical characteristic and a good switching ratio over a wide range of voltage.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"175 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":"132601881","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}
{"title":"Performance Analysis of Graphene Bilayer Transistors Through Tight-Binding Simulations","authors":"G. Fiori, G. Iannaccone","doi":"10.1109/IWCE.2009.5091138","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091138","url":null,"abstract":"A simulation study of a tunable-gap bilayer graphene FET with independent gates is performed with a numerical solver based on the self-consistent solution of the Poisson and Schrodinger equations within the NEGF formalism. The applied vertical field manages to induce an energy gap, but its value is not large enough to suppress band-to-band tunneling and to obtain acceptable I ON /I OFF ratio for CMOS device operation.","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":"127349104","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}
Sunhee Lee, H. Ryu, Zhengping Jiang, Gerhard Klimeck
{"title":"Million Atom Electronic Structure and Device Calculations on Peta-Scale Computers","authors":"Sunhee Lee, H. Ryu, Zhengping Jiang, Gerhard Klimeck","doi":"10.1109/IWCE.2009.5091117","DOIUrl":"https://doi.org/10.1109/IWCE.2009.5091117","url":null,"abstract":"Semiconductor devices are scaled down to the level which constituent materials are no longer considered continuous. To account for atomistic randomness, surface effects and quantum mechanical effects, an atomistic modeling approach needs to be pursued. The Nanoelectronic Modeling Tool (NEMO 3-D) has satisfied the requirement by including empirical sp 3 s* and sp 3 d 5 s* tight binding models and considering strain to successfully simulate various semiconductor material systems. Computationally, however, NEMO 3-D needs significant improvements to utilize increasing supply of processors. This paper introduces the new modeling tool, OMEN 3-D, and discusses the major computational improvements, the 3-D domain decomposition and the multi-level parallelism. As a featured application, a full 3-D parallelized Schrodinger-Poisson solver and its application to calculate the bandstructure of delta doped phosphorus(P) layer in silicon is demonstrated. Impurity bands due to the donor ion potentials are computed.","PeriodicalId":443119,"journal":{"name":"2009 13th International Workshop on Computational Electronics","volume":"2674 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":"126995587","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}