SHAIKH S. AHMED

Assistant Professor

Department of Electrical and Computer Engineering

Southern Illinois University Carbondale

1230 Lincoln Drive

Carbondale, IL 62901

Telephone: (618) 453-7630

Fax: (618) 453-7972

Email: ahmed@siu.edu

Post-Doctoral Research Associate (2005–2007)

School of Electrical and Computer Engineering and

Network for Computational Nanotechnology

Purdue University, West Lafayette, Indiana, USA

Ph.D. in Electrical Engineering (2003–Jan., 2005)

Nanostructures Research Group

Department of Electrical Engineering, Arizona State University, Tempe, Arizona, USA.

Dissertation title: Quantum and Coulomb Effects in Nanoscale Devices.

M.S. in Electrical Engineering (2001–2003)

Department of Electrical Engineering, Arizona State University, Tempe, Arizona, USA.

Thesis title: Modeling of Silicon-On-Insulator Devices.

B.S. in Electrical and Electronic Engineering (1993–1998)

Bangladesh University of Engineering & Technology (BUET), Dhaka, Bangladesh.

Thesis: Design and simulation of Log-Periodic Yagi-Uda Antennas.

Assistant Professor (Aug. 2007– )

Department of Electrical and Computer Engineering

Southern Illinois University Carbondale

Post-Doctoral Research Associate (2005−2007)

School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana, USA.

·        Development of comprehensive full three-dimensional quantum simulators (mainly based on non-equilibrium Green’s function) for nanowires, nanotubes, molecular devices, and other novel nanoscale semiconductor devices.

·        Study impacts of defects and disorder on the transport properties of single-walled semiconducting/metallic Carbon nanotubes.

·        Study bandstructure and crystal orientation effects in novel nanoscale devices.

·        Modeling monolithic (In,Ga)N nanorod array LED fabricated on a low-cost metallized silicon substrate.

·        Study quantum Hall effect and beyond in novel Graphene nanoribbons using NEGF approach.  

·        Study electronic structure with an emphasis on the symmetry breaking/lowering (optical anisotropy) and the fine structure and level splitting (non-degeneracy) in self-assembled zincblende quantum dots through atomistic simulations of long-range strain and piezoelectric field. 

·        Study strain and electronic structure interactions in realistically-scaled quantum dot stacks in the design of quantum cascaded lasers.

·        Development of novel parallel algorithms and methodologies for solving non-equilibrium Green’s functions from large sparse matrix systems and novel algorithms for molecular dynamics and electrostatics.

·        Cooperating with the NCN (Network for Computational Nanotechnology) team in developing generalized numerical computational tools for use in the community software on the www.nanohub.org.

·        Modeling and characterization of low frequency noise in nanoscale CNTs and MOSFETs.

Graduate Research Assistant (2001−2004)

Department of Electrical Engineering, Arizona State University, Tempe, Arizona, USA.

·        Developed a parameter-free quantum potential approach for use in conjunction with particle-based simulations. The method is based on a perturbation theory around thermodynamic equilibrium and leads to a quantum field formalism in which the size of an electron depends upon its energy.

·        Developed a full 3D Monte-Carlo particle based simulator coupled with an effective potential scheme to investigate the quantum effects occurring in recently proposed narrow-width SOI devices.

·        Investigations of the impact of discrete/unintentional doping induced variations on the performance of nanoscale devices. Three different but consistent real-space molecular dynamics (MD) schemes have been implemented: the particle-particle-particle-mesh (P³M) method, the corrected Coulomb approach and the Fast Multipole Method (FMM).

·        Developed and implemented a self-consistent event-biasing scheme for statistical enhancement in the particle-based Monte-Carlo device simulations.

·        Modeling and simulation of Focused Ion Beam MOSFET (FIBMOS) devices.

·        Modeling and simulation of Schottky Junction Transistors (SJTs). The device was found to offer higher mobility and transconductance than its conventional counterpart.

·        Study and simulation of ballistic transport in mesoscopic devices using the transfer matrix formalism.

·        Worked on developing Hydrodynamic and Extended Drift-Diffusion models to simulate thin film electro-luminescent (TFEL) devices.

·        Investigations (in progress) of the applicability of the Fast Multipole Method (FMM) and other MD methods to the simulations of non-classical FinFETs and Ionic Liquids/Ion Channels.

·        HgFET Pseudo-MOSFET (ψ-MOSFET) characterization/measurement/modeling of silicon-on-insulator (SOI) material by Four Dimensions CV Map 92-B System allowing threshold voltage, electron and hole mobility, doping density, oxide charge, interface trap density, etc. to be determined. A SIMOX wafer (p-type, 8.5-14 ohm-cm) was used in this study.

Substitute Lecturer for Prof. Dragica Vasileska (2002–2004)

Department of Electrical Engineering, Arizona State University

Substituted for Prof. Dragica Vasileska, between 2001 and 2005, for courses listed below:

·        Electrical Network-I (EEE 201)

·        Semiconductor Device Theory I (EEE 531)

·        Semiconductor Device Theory II (EEE 532)

·        Semiconductor Process/Device Simulation (EEE 533)

·        Semiconductor Transport (EEE 534)

·        Introduction to Solid State Electronics (EEE 539)

Lecturer (1999–2000)

Islamic University of Technology, Gazipur, Dhaka, Bangladesh.

Courses Instructed: Electromagnetic Fields and Waves, Integrated Circuits, Advanced Electronics, Electrical Measurement & Instrument. Lab, Electrical Machines Lab.

Teaching Assistant (1998–1998)

Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh.

Courses Instructed: Electronics Lab., Industrial Electronics Lab., Microwave Systems and Circuits Lab.

·        Graduate Tuition Scholarship, 2001-04, Arizona State University

·        Dean’s List Scholarship in BUET

·        BUET Merit Scholarship

·        Secondary and Higher Secondary Education Board Merit Scholarship

·        Member Secretary of Electrical & Electronic Engineering Department of IUT

·        Member of American Physical Society (APS)

·        Member of IEEE

·        Reviewer of Physical Review Letter, Physical Review B, IEEE Trans. of Electron Devices,

Applied Physics Letter, and Journal of Applied Physics

·        Marquis’ Who’s Who in America

Book Chapters

1.       Shaikh Ahmed, Neerav Kharche, Rajib Rahman, Muhammad Usman, Sunhee Lee, Hoon Ryu, Hansang Bae, Steve Clark, Benjamin Haley, Maxim Naumov, Faisal Saied, Marek Korkusinski, Rick Kennel, Michael Mclennan, Timothy B. Boykin, And Gerhard Klimeck, “Multimillion Atom Simulations with NEMO 3-D”, Encyclopedia of Complexity and System Science. Springer-Verlag 2008 (accepted and to appear in Dec. 2008).

2.       Shaikh S. Ahmed, Dragica Vasileska, “Modeling of Narrow-Width SOI Devices: The Role of Quantum Mechanical Narrow Channel Effects on Device Performance”, 105-111, Large Scale Scientific Computing. Springer-Verlag 2004.

Major Journal Publications

1.       Himadri S. Pal, Kurtis D. Cantley, Shaikh S. Ahmed, and Mark S. Lundstrom, "Influence of Bandstructure and Channel Structure on the Inversion Layer Capacitance of Silicon and GaAs MOSFETs", IEEE Transactions on Electron Devices, Vol. 55, Issue 3, pp 904-908, 2008.

2.       S. Ahmed, Gerhard Klimeck, Derrick Kearney, Michael McLennan, MP Anantram, “Quantum Simulations of Dual Gate MOSFET Devices: Building and Deploying Community Nanotechnology Software Tools on NanoHUB.org”, J. High Speed Electronics, Vol 17, Issue, 3, pp 485-494, 2007.

3.       D. Vasileska, H. Khan, and S. Ahmed, "Modleing Coulomb effects in nanoscale devices", Int. J. Nanoscience (in process).

4.       S. Li, S. Ahmed, E. Darve, and G. Klimeck, "Compute the Diagonal of Sparse Matrix Inverse using FIND Algorithm", Jour. Computational Physics (accepted).

5.       Gerhard Klimeck, Shaikh Ahmed, Neerav Kharche, Hansang Bae, Steve Clark, Benjamin Haley, Sunhee Lee, Maxim Naumov, Hoon Ryu, Faisal Saied, Marta Prada, Marek Korkusinski, and Timothy B. Boykin, “Atomistic Simulation of Realistically Sized Nanodevices Using NEMO 3-D: Part I – Models and Benchmarks”, IEEE Transactions on Electron Devices, Vol 54, No 9, September 2007.

6.       Gerhard Klimeck, Shaikh Ahmed, Neerav Kharche, Marek Korkusinski, Muhammad Usman, Marta Prada, and Timothy B. Boykin, “Atomistic Simulation of Realistically Sized Nanodevices Using NEMO 3-D: Part II – Applications”, IEEE Transactions on Electron Devices, Vol 54, No 9, September 2007.

7.       Neophytos Neophytou, Shaikh Ahmed, Gerhard Klimeck, “Non-Equilibrium Green’s Function (NEGF) Simulation of Metallic Carbon Nanotubes: The Effect of the Vacancy Defect”, Journal of Computational Electronics, Volume 6, Numbers 1-3, pp. 317-320, September, 2007.

8.       C. Heitzinger, C. Ringhofer, S. Ahmed, and D. Vasileska, “3D Monte-Carlo Device Simulations Using an Effective Quantum Potential Including Electron-Electron Interactions”, Journal of Computational Electronics, Volume 6, Numbers 1-3, pp. 15-18, September, 2007.

9.       Neophytos Neophytou, Shaikh Ahmed, Gerhard Klimeck, “Influence of vacancies on metallic nanotube transport performance”, Applied Physics Letter, 90, 182119, 2007.

10.    S. Li, S. Ahmed, and E. Darve, “Fast Inverse using Nested Dissection for NEGF”, Journal of Computational Electronics, Volume 6, Numbers 1-3, pp. 187-190, September, 2007.

11.    S. Ahmed, M. Usman, C. Heitzinger, R. Rahman, A. Schliwa,  and G. Klimeck, “Atomistic Simulation of Non-Degeneracy and Optical Polarization Anisotropy in Zincblende Quantum Dots”, IEEE NEMS, 2007.

12.    AKM. Ahsan and S. Ahmed, “Impact of Halo Angle on 1/f noise in Conventional MOSFET technology”, Journal of Solid State Electronics, vol. 50, pp.1705–1709, 2006.

13.    D. Vasileska and S. Ahmed, “Narrow-Width SOI Devices: The Role of Quantum Mechanical Size Quantization Effect and the Unintentional Doping on the Device Operation”, IEEE Transactions on Electron Devices, vol. 52, pp. 227–236, 2005.

14.    S. Ahmed, C. Ringhofer, D. Vasileska, “Parameter-Free Effective Potential Method for Use in Particle-Based Device Simulations”, IEEE Transactions on Nanotechnology, Vol. 4, pp. 465–471, July 2005.

15.    Shaikh Ahmed, Dragica Vasileska and Christian Ringhofer, “Quantum potential approach to modeling nanoscale MOSFETs”, Journal of Computational Electronics, vol. 4, pp. 57–61, 2005.

16.    D. Vasileska, H. R. Khan and S. S. Ahmed, “Quantum and Coulomb Effects In Nanodevices”, International Journal of Nanoscience, Vol. 4, No. 3,  pp. 305–361, 2005, World Scientific Publishing Company.

17.    J. Choi, S. Ahmed, T. Dimitrova, J. Chen, and D. K. Schroder, “The Role of the Mercury-Si Schottky-Barrier Height in ψ-MOSFETs”, IEEE Transactions on Electron Devices, vol. 51, pp. 1164–1168, 2004.

18.    K. Tarik, S. Ahmed, D. Vasileska and T.J. Thornton, “Subthreshold Mobility Extraction for SOI-MESFETs”, Journal of Computational Electronics, vol. 3, pp. 243–246, 2004.

19.    H. Khan, S. Ahmed, and D. Vasileska, C. Heitzinger, C. Ringhofer “Modeling of FinFET: 3D MC Simulation Using FMM and Unintentional Doping Effects on Device Operation”, Journal of Computational Electronics, vol. 3, pp. 337–340, 2004.

20.    Shaikh Ahmed and Dragica Vasileska, “Inclusion of Short-Range Interactions in Monte Carlo Simulations of Nanoscale Devices”, Monte Carlo Methods and Applications, Vol. 10, No. 3-4, pp. 629–641, 2004.

21.    M. Nedjalkov, S. Ahmed, and D. Vasileska, “A self-consistent event biasing scheme for statistical enhancement”, Journal of Computational Electronics, vol. 3, pp. 305–309, 2004.

22.    S. Ahmed, C. Ringhofer, and D. Vasileska, “An effective potential approach to modeling 25 nm MOSFET devices”, Journal of Comp. Electronics, vol.2, pp. 113–117, 2003.

23.    S. Ahmed and D. Vasileska, “Threshold voltage shifts in narrow-width SOI devices due to quantum mechanical size-quantization effects”, Physica E, vol. 19, pp. 48–52, 2003.

24.    S. Ahmed and Dragica Vasileska, “Modelling of narrow-width SOI devices”, Semicond. Science and Tech., vol. 19, pp. 131-133, 2004.

25.    S. Ahmed, C. Ringhofer, and D. Vasileska, “A thermodynamic approach to quantum potential approach to modeling of 25 nm MOSFET devices”, Superlattices and Microstructures, vol. 34, pp.311–317, 2003.

26.    D. Vasileska, R. Akis, I. Knezevic, S. N. Milicic, Shaikh S. Ahmed, and D. K. Ferry, "The role of quantization effects in the operation of ultrasmall MOSFETs and SOI devices", Microelectronic Engineering, vol 63, pp. 233–237, 2002.

27.    D. Vasileska, I. Knezevic, R. Akis, S. Ahmed, and D. K. Ferry, "The Role of Quantum Effects on the Operation of 50 nm MOSFETs, 250 nm FIBMOS Devices and Narrow-Width SOI Device Structures", Journal of Comp. Electronics, vol 1, pp. 453–457, 2002.

28.    S. Ahmed and D. Vasileska, “Narrow-Width SOI Devices: Impact of Quantum Mechanical Space-Quantization Effects on Device Performance”, IEEE Nano, pp. 223–246, 2002.

Major Refereed Archival Conference Papers/Presentations

1.       Muhammad Usman, Shaikh Ahmed, and Gerhard Klimeck, "Strain and Piezoelectric Effects on the Electronic Structure of Coupled InxGa1-xAs/GaAs Self-Assembled Quantum Dots", APS march meeting 2008, New Orleans, LA, USA.

2.       Shaikh Ahmed, "Intrinsic parameter variations in nanoscale devices", IUCRC, St. Luis, Dec 2007.

3.       Roksana Golizadeh-Mojarad, A.N.M. Zainuddin, Shaikh S. Ahmed, Gerhard Klimeck, Supriyo Datta, “Atomistic NEGF Simulations of Carbon Nano-Ribbons in Magnetic Fields”, IWCE, UM Amherst, 2007.

4.       Kurtis D. Cantley, Yang Liu, Himadri S. Pal, Tony Low, Shaikh S. Ahmed, and Mark S. Lundstrom, “Performance Analysis of III-V Materials in a Double-Gate nano-MOSFET”, IEDM, December 10-12, 2007, Hilton Washington, Washington, DC (accepted).

5.       Shaikh Ahmed, Muhammad Usman, Neerav Kharche, Andrei Schliwa, and Gerhard Klimeck, “Atomistic Simulation of Non-Degeneracy and Optical Polarization Anisotropy in Pyramidal Quantum Dots”, IEEE NEMS, Bangkok, Thailand, 2007.

6.       E. Ramayya, S. S. Ahmed, D. Vasileska, S. M. Goodnick and I. Knezevic, “Mobility of Electrons in Rectangular Si nanowires”, in Technical Proceeding of the 2006 Nanotech Conference, Vol. 3, pp. 13 – 15, 2006.

7.       Neophytos Neophytou, Shaikh Ahmed, Diego Kienle, Mark Lundstrom, Gerhard Klimeck, “Building and Deploying Community Nanotechnology Software Tools on nanoHUB.org – Non-Equilibrium Green's Function Simulations of the Impact of Atomic Defects on the Performance of Carbon Nanotube Transistors”, 2006 APS March Meeting, Monday–Friday, March 13–17, 2006, Baltimore, MD, USA.

8.       Gerhard Klimeck, Shaikh Ahmed, Marek Korkusiniski, Seungwon Lee, Faisal Saied, “Atomistic Simulations of Long-Range Strain and Close-Range Electronic Structure in Self-Assembled Quantum Dot Systems”, 2006 APS March Meeting, Monday–Friday, March 13–17, 2006, Baltimore, MD, USA.

9.       Shaikh Ahmed, Dragica Vasileska, Gerhard Klimeck, Christian Ringhofer, “Efficacy of the Thermalized Quantum Potential Approach for Modeling Nanoscale Semiconductor Devices”, 2006 APS March Meeting, Monday–Friday, March 13–17, 2006, Baltimore, MD, USA.

10.    Shaikh Ahmed, M. P. Anantram, Neophytos Neophytou, Marek Korkusinski, Gerhard Klimeck, “Quantum Simulations of Electronic Structure and Transport Properties in Conventional and Novel Nanoscale Devices”, 7th World Congress on Computational Mechanics, Los Angeles 2006.

11.    Neophytos Neophytou, Shaikh Ahmed, M.P. Anantram and Gerhard Klimeck, “Non-Equilibrium Green’s Function (NEGF) Simulation of Metallic Carbon Nanotube Transistors: Impact of Vacancy Defect”, IWCE, Vienna, Austria, 2006.

12.    Shaikh Ahmed, Muhammad Usman, Clemens Heitzinger, Rajib Rahman, Andrei Schliwa, and Gerhard Klimeck “Symmetry breaking and fine structure splitting in self-assembled zincblende quantum dots: atomistic simulations of long-range strain and piezoelectric field”, ICPS 2006, Vienna, Austria, July 24-28 2006 .

13.    Gerhard Klimeck, Rick Kennel, Michael McLennan, Stephen Clark, Clemens Heitzinger, Shaikh S. Ahmed, Wei Qiao, David Ebert,  Sebastien Goasguen, Krishna Madhavan, “nanoHUB.org – A fully operational Science  Gateway for the nano Science Community”, The Second IEEE/ACM International Workshop on High Performance Computing for Nano-science and Technology (HPCNano06), Nov. 13, 2006, Tampa, Florida, USA (Invited).

14.    S. Ahmed, M. Usman, C. Heitzinger, R. Rahman, A. Schliwa,  and G. Klimeck, “Atomistic Simulation of Non-Degeneracy and Optical Polarization Anisotropy in Zincblende Quantum Dots”, The 2nd Annual IEEE International Conference on Nano/Micro Engineered and Molecular Systems (IEEE-NEMS), Bangkok, Thailand, Jan 16-19, 2007.

15.    Gerhard Klimeck, Shaikh Ahmed, Clemens Heitzinger, Neerav Kharche, Muhammad Usman, Mathieu Luisier, Raesong Kim, Neophytos Neophytou, Michael McLennan, and Timothy B. Boykin, “Quantum Dot, Nanowire, and Bandstructure Modeling, and Deployment On Nanohub.Org”, International Workshop Tera- and Nano-Devices: Physics and Modeling, October 16-19, 2006, Aizu, Japan (Invited).

16.    Shaikh S. Ahmed, Marek Korkusinski, Faisal Saied, Haiying Xu, Seungwon Lee, Mohamed Sayeed, Sebastien Goasguen and Gerhard Klimeck, “Large Scale Simulation in Nanostructures with NEMO3-D on Linux Clusters”, The 6th LCI International Conference on Linux Clusters: The HPC Revolution 2005, April 26-28, 2005, The Carolina Inn, University of North Carolina, Chapel Hill, North Carolina, USA.

17.    Shaikh Ahmed, “Building and Deploying Community Nanotechnology Software Tools on nanoHUB.org – Atomistic Simulations of Multimillion-Atom Quantum Dot Nanostructures”, I-light Symposium 2005, Indiana University, September 2005.

18.    Dragica Vasileska, Shaikh Ahmed, Christian Ringhofer, “Quantum Effects Incorporation into Monte Carlo Device Simulators for Modeling Nano-Scale Devices”, 2nd Annual Conference on Foundations of Nanoscience: Self-Assembled Architectures and Devices (Fnano05), Snowbird Cliff Lodge, Snowbird, UT, April 24 –April 28, 2005.

19.    H. Khan, S.S. Ahmed, D. Vasileska, “Examination of the Effects of Unintentional Doping on the Operation of FinFETs with Monte Carlo Simulation Integrated with Fast Multipole Method (FMM)”, 2005 NSTI Nanotech Conference & Trade Show, Anaheim, May 8-12, 2005.

20.    S. Ahmed and D. Vasileska, “The Influence of Unintentional Doping on nanoscale MOSFET Operation”, IVth IMACS Seminar on Monte Carlo Methods MCM, 15–19 September 2003, Berlin, Germany.  

21.    S. S. Ahmed, R. Akis and D. Vasileska, "Quantum Effects in SOI Devices: A Scattering matrix calculation based on Landauer’s formalism", 4^th International Conference on Modeling and Simulation of Microsystems, San Juan, Puerto Rico, USA, pp. 518–521, April 22–25, 2002.

22.    S.S. Ahmed and D. Vasileska, “Quantum effects in narrow-width SOI devices”, MSED Proc., Barcelona, Spain, September 2003.

23.    C. Heitzinger, S. Ahmed, C. Ringhofer, and D. Vasileska, “On the Influence of the Number of Moments in the Boltzmann Transport Equation Compared to the Hydrodynamic Transport Model”, Proc. 34th European Solid-State Dev. Res. Conference ESSDERC, September 2004, Leuven, Belgium.

24.    S. S. Ahmed, R. Akis and D. Vasileska, "Modeling of Narrow-Width SOI devices", 2002 IEEE Si Nanoelectronics Workshop, Honolulu, Hawaii, USA, June 9-10, 2002.

25.    S. S. Ahmed, and D. Vasileska, “Narrow-Width SOI Devices: Impact of Quantum Mechanical Space-Quantization Effects on Device Performance”, IEEE-NANO 2002, Arlington, Virginia, USA, August 26–28, 2002.

26.    S. S. Ahmed, and D. Vasileska, “Quantum mechanical narrow-channel effect in SOI devices”, in the Proc. of the 4th Int. Symp. on Nanostructures and Mesoscopic Systems  (NanoMes), Tempe Mission Palms Hotel, Tempe, Arizona, USA, February 17–21, 2003.

27.    S. Ahmed, C. Ringhofer, and D. Vasileska, “Effective potential approach to modeling of 25 nm MOSFET devices”, Sixth International Conference on New Phenomena in Mesoscopic Systems (NPMS-6) and Fourth International Conference on Surfaces and Interfaces of Mesoscopic Devices (SIMD-4), Maui, Hawaii, USA, December 1–5, 2003.

28.    C. Heitzinger, S. Ahmed, C. Ringhofer, and D. Vasileska, “Efficient Simulation of the Full Coulomb Interaction in Three Dimensions”, Proc. 9th International Workshop on Computational Electronics (IWCE 10), Purdue University, 2004.

29.    S. Ahmed and D. Vasileska, “Threshold voltage shifts in narrow-width SOI devices due to quantum mechanical size-quantization effects”, Technical Proceedings of the Nanotechnology Conference and Trade Show, San Fransisco, California, USA, pp. 222–225, Feb. 23–27, 2003.

30.    C. Ringhofer, D. Vasileska, S. Ahmed, “A thermodynamic quantum potential approach”, Workshop on Quantum and Many-Body Effects in Nanoscale Devices, Arizona State University, Tempe, Arizona, October 24–25, 2003. 

31.    S. Ahmed and D. Vasileska, “Modelling of narrow-width SOI devices”, 13th International Conference on Nonequilibrium Carrier Dynamics in Semiconductors (HCIS-13), July 28-August 01, 2003, Italy.

32.    C. Heitzinger, S. Ahmed, C. Ringhofer, and D. Vasileska, “Accurate Three-Dimensional Simulation of Electron Mobility Including Electron-Electron and Electron-Dopant Interactions”, Proc. 206th Meeting of the Electrochem Soc. ECS, October 2004, Honolulu, HI, USA.

33.    S. Ahmed and D. Vasileska, “Coulomb Effects on Nanoscale MOSFET Operation”, Fourth IEEE Conference on Nanotechnology, August 17-19, 2004, Munich, Germany.

34.    S. Ahmed, C. Ringhofer, and D. Vasileska, “Quantum potential for use in particle based simulations”, Proc. 9th International Workshop on Computational Electronics (IWCE 9), 25–28 May 2003, Italy.

35.    S. S. Ahmed, and D. Vasileska, “Modeling of Narrow-Width SOI Devices: The Impact of Quantum Mechanical Size Quantization Effects and Unintentional Doping on Device Operation”, 62^nd Device Research Conference DRC, University of Notre Dame Notre Dame, Indiana, USA, June 21-23, 2004.

36.    C. Heitzinger, S. Ahmed, C. Ringhofer, and D. Vasileska, “On the Efficient Simulation of Electron-Electron Interactions in Nanoscale MOSFETs”, Proc. Trends in Nanotechnology, TNT September 2004, Segovia, Spain.

37.    T. Khan, S. Ahmed, T. Thornton, D. Vasileska, “Subthreshold mobility modeling of SOI MESFETs”, IWCE 2004, Purdue University, West Lafayette, USA, October 2004.

Contribution to scientific nanotechnology software development: freely available on nanoHUB.org

1.       nanoFET. simulates ballistic transport properties in two-dimensional classical and novel MOSFET devices. The overall F90 & C⁺⁺ simulation framework consists of the non-equilibrium Green’s function equations solved self-consistently with Poisson’s equation. Four different algorithms have been employed ― (1) Recursive Green’s function, RGF (2) Fast Inverse using Nested Dissection, FIND (3) A parallel RGF solver, PDIV and (4) another parallel RGF solver in F90, SPIKE. A friendly GUI based on Rappture is provided. Simulation is freely available on NanoHUB.org.

2.       CNTFET. can currently simulate the impact of quantum mechanical size quantization and phase coherence in zigzag carbon nanotubes with both planar and coaxial exterior architectures. The package is based on non-equilibrium Greens’ function (NEGF) techniques using a pz-orbital nearest-neighbor tight binding. Full three-dimensional (3D) electrostatics has been captured by the Finite-Element-Method (FEM) of solving the Poisson Equation. Solution of this set of equations is computationally intensive. One can reduce the simulation time by using a mode-space approach instead of the real-space approach. By default the simulator solves for both electrons and holes. A friendly GUI based on Rappture is provided. The simulation is freely available on NanoHUB.org.

3.       QuaMC. (pronounced as quam-see) is a quasi three-dimensional quantum-corrected diffusive semiclassical Monte Carlo transport simulator for conventional and non-conventional MOSFET devices. A parameter-free quantum field approach has been developed and utilized quite successfully in order to capture the size-quantization effects in nanoscale MOSFETs. The method is based on a perturbation theory around thermodynamic equilibrium and leads to a quantum field formalism in which the size of an electron depends upon its energy. Also in this simulator, the use of self-consistent event-biasing schemes for statistical enhancement in the Monte Carlo device simulations has been presented. The simulation is freely available on NanoHUB.org.

4.       FETToy. calculates the ballistic I-V characteristics for a conventional MOSFETs, Nanowire MOSFETs and Carbon Nanotube MOSFETs. Only the lowest subband is considered, but it is readily modifiable to include multiple subbands.

5.       MOSCap: Simulates the capacitance of bulk and dual gate capacitors for a variety of different device sizes, geometries, temperature and doping profiles.

6.       MOSFET. Simulates the capacitance of bulk and SOI Field Effect Transistors (FETs) for a variety of different device sizes, geometries, temperature and doping profiles. Enables the visualization of various device characteristics such as Id-Vd and Id-Vg. MOSFET lab is based on the Padre simulation tool developed by Mark Pinto, R. Kent Smith, and Ashraful Alam at Bell Labs.

7.       nanoMOS 3.0. NanoMOS is a 2-D simulator for thin body (less than 5 nm), fully depleted, double-gated n-MOSFETs. A choice of five transport models is available (drift-diffusion, classical ballistic, energy transport, quantum ballistic, and quantum diffusive). The quantum transport models are based on mode-space method within an effective mass approximation. Scattering in the device can also be treated by a simple model that uses so-called Büttiker probes.

8.       Schred 2.0. Calculates the envelope wavefunctions and the corresponding bound-state energies in a typical MOS (Metal-Oxide-Semiconductor) or SOS (Semiconductor-Oxide-Semiconductor) structure and a typical SOI structure by solving self-consistently the one-dimensional (1D) Poisson equation and the 1D Schrodinger equation.