EDUCATION
Post-Doctoral Research Associate (Feb, 2005–)
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
WORK/RESEARCH EXPERIENCE
Post-Doctoral Research Associate (Spring, 2005−)
School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana, USA.
1. Development of comprehensive full three-dimensional quantum simulators for nanowires, nanotubes, molecular devices, and other novel nanoscale semiconductor devices.
2. Study of charge and spin -based quantum qubit systems using the NEMO 3D code.
4. Study of impacts of defects on the transport properties of single-walled metallic Carbon nanotubes.
5. Study of symmetry breaking and fine structure splitting in self-assembled Zincblende quantum dots through atomistic simulations of long-range strain and piezoelectric field.
5. Development of novel algorithms and methodologies for solving non-equilibrium Green’s functions from large sparse matrix systems.
6. Modeling and characterization of low frequency noise in nanoscale MOSFETs.
7. Cooperating with the NCN (Network for Computational Nanotechnology) team towards providing and developing generalized numerical computational tools for use in the community software on the www.nanohub.org.
8. Collaborated with Rensselaer Polytechnic Institute, NASA Marshall Space Flight Center, Georgia State University, NASA Jet Propulsion Laboratory, California Institute of Technology in preparing a proposal for NASA Research Opportunities in Space and Earth Sciences-2005 (ROSES) on Development of a Far Infrared Simulator and Device for Exploration Applications.
Graduate Research Assistant (2001−2004)
Department of Electrical Engineering, Arizona State University, Tempe, Arizona, USA.
1. Developed a parameter-free quantum field 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.
2. 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.
3. Investigations of the impact of unintentional/discrete doping on the performance of SOI 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).
4. Developed and implemented a self-consistent event-biasing scheme for statistical enhancement in the particle-based Monte-Carlo device simulations.
5. Modeling and simulation of Focused Ion Beam MOSFET (FIBMOS) devices.
6. Modeling and simulation of Schottky Junction Transistors (SJTs). The device was found to offer higher mobility and transconductance than its conventional counterpart.
7. Study and simulation of ballistic transport in mesoscopic devices using basically the transfer matrix formalism.
8. Worked on developing Hydrodynamic and Extended Drift-Diffusion models to simulate Thin Film Electro-Luminescent (TFEL) devices.
9. Investigations (in progress) of the applicability of the Fast Multipole Method (FMM) and other MD methods to the simulations of non-classical MOSFETs (FinFETs) and Ionic Liquids/Ion Channels.
10. 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.
TEACHING EXPERIENCE
Substitute Lecturer for Prof. Dragica Vasileska (2002–2004)
Department of Electrical Engineering, Arizona State University
Substituted for Prof. Dragica Vasileska, many times between 2002 and present,
for a total of 7 courses (listed below):
Electrical Network-I (EEE 201)
Quantum Mechanics for Engineers (EEE 434)
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, Digital Systems design, Advanced Electronics, Electrical Measurement & Instrument. Lab, VLSI Design Lab, Electrical Machines Lab.
Teaching Assistant (1998–1998)
Bangladesh University of Engineering and Technology (BUET), Dhaka.
Courses Instructed: Electronics Lab., Industrial Electronics Lab., Microwave Systems and Circuits Lab.
HIGH PERFORMANCE COMPUTING AND SCIENTIFIC SOFTWARE SKILLS
Scientific Software: PADRE, SILVACO, MEDICI, MINIMOS, TSUPREM4, Prophet, RasMol, QClab, NEMO3D,
Nessie, Schred, NanoMOS, QuaMC, CPMD, PWscf, NanoFET, CNTFET, SiNW, MOCA,
BioMOCA, HSpice, OrCAD, Pspice, Mentor Graphics, LASI.
Operating Systems: UNIX/LINUX Professional, Mac OSX, Windows 2000/XP/NT.
Languages: C/C++, FORTRAN90/95/2003, Python, Tcl, XML, DOM parser development, Parallel Programming (MPI, OpenMP) and Cluster Computing, RCS/CVS/SVN repository systems handling.
Visualization: Advanced visualization techniques including animation and 3-D representation.
RELEVANT GRADUATE LEVEL COURSEWORK/STUDY TOPICS
Quantum Mechanics
Solid State Electronics
Semiconductor Transport
Quantum Transport in Nanostructures
Electronic Transport in Mesoscopic Systems
Semiconductor Device & Process Simulation
Advanced Silicon Processing
Semiconductor Device Theory-I
Semiconductor Device Theory-II
Advanced MOS Devices
Semiconductor Device Characterization
SOI Devices: Modeling and Characterization
Advanced Mathematics for Physics and Engineering (MIT-online-audit)
Computational Materials Science (MIT-online-audit)
Advanced CMOS Analog Integrated Circuits
Analog to Digital (A/D) Converters
VLSI Design
Analog Integrated Circuits
Digital Systems and Circuits
HONORS/ACTIVITIES
· Graduate Tuition Scholarship, 2001-04, Arizona State University.
· Dean’s List Scholarship in BUET.
· BUET Merit Scholarship.
· Member Secretary of Electrical & Electronic Engineering Department of IUT.
· Member of American Physical Society (APS).
· 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
PUBLICATIONS/ DEVELOPMENT
Published Book Chapter
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. 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. S. Ahmed and Dragica Vasileska, “Modelling of narrow-width SOI devices”, Semicond. Science and Tech., vol. 19, pp. 131-133, 2004.
9. 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.
10. 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.
11. 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.
12. 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.
13. 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.
14. Shaikh Ahmed, Dragica Vasileska and Christian Ringhofer, “Quantum potential approach to modeling nanoscale MOSFETs”, Journal of Computational Electronics, vol. 4, pp. 57–61, 2005.
15. 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.
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. S. Li, S. Ahmed, and E. Darve, “Fast Inverse using Nested Dissection for NEGF”, Journal of Computational Electronics (in press).
18. 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 (in press).
19. 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 (in press).
Major Refereed Archival Conference Papers/Presentations
20. 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.
21. 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.
22. 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.
23. 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.
24. 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.
25. 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 .
26. 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).
27. 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.
28. 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).
29. 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.
30. 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.
31. 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.
32. 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.
33. 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.
34. S. S. Ahmed, R. Akis and D. Vasileska, "Quantum Effects in SOI Devices: A Scattering matrix calculation based on Landauer’s formalism", 4th International Conference on Modeling and Simulation of Microsystems, San Juan, Puerto Rico, USA, pp. 518–521, April 22–25, 2002.
35. S.S. Ahmed and D. Vasileska, “Quantum effects in narrow-width SOI devices”, MSED Proc., Barcelona, Spain, September 2003.
36. 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.
37. 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.
38. 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.
39. 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.
40. 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.
41. 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.
42. 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.
43. 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.
44. 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.
45. 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.
46. S. Ahmed and D. Vasileska, “Coulomb Effects on Nanoscale MOSFET Operation”, Fourth IEEE Conference on Nanotechnology, August 17-19, 2004, Munich, Germany.
47. 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.
48. 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”, 62nd Device Research Conference DRC, University of Notre Dame Notre Dame, Indiana, USA, June 21-23, 2004.
49. 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.
50. T. Khan, S. Ahmed, T. Thornton, D. Vasileska, “Subthreshold mobility modeling of SOI MESFETs”, IWCE 2004, Purdue University, West Lafayette, USA, October 2004.
Submitted and In-Line Papers
51. S. Ahmed, Gerhard Klimeck, Michael McLennan, MP Anantram, “Quantum Simulations of Dual Gate MOSFET Devices: Building and Deploying Community Nanotechnology Software Tools on NanoHUB.org”, submitted to J. H. Speed Electronics.
52. N. Neophytou, S. Ahmed, G. Klimeck, “Impact of Defects on Metallic Carbon Nanotubes”, submitted to Appl. Phy. Letter.
53. S. Ahmed, M. Usman, G. Klimeck, “Strain and electronic structure interactions in realistically-scaled quantum dot stacks”, for Appl. Phy. Letter.
54. S. Ahmed, N. Neophytou, E. Pollizzi, G. Klimeck, “CNTFET — A Full Three-Dimensional Non-Equilibrium Green’s Function (NEGF) Based Simulator for Carbon Nanotube FETs”, for J. Appl. Physics.
55. S. Ahmed, M. Usman, G. Klimeck, A. Schliwa, “Atomistic Simulation of Non-Degeneracy and Optical Polarization Anisotropy in Zincblende Quantum Dots”, for Phys. Rev. B.
56. AKM. Ahsan and S. Ahmed, “Impact of Halo Angle on 1/f noise in Conventional MOSFET technology”, Submitted to Journal of Solid State Electronics, 2006.