CNTFET, FinFET and MESFET Md. Rakibul Karim Akanda University of California Riverside, California, USA
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 1. Schematic cross-sectional view of the wraparound gate multi-CNTchannel FET. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 2. Approximate cross-sectional view of the CNTFET with gate-tochannel capacitance for the end CNT channel (Cgc,e) and the middle CNT channel (Cgc,m). Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 3. Conceptual representation of the wraparound gate CNTFET illustrating the image charge distribution of the CNT channel. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 4. Schematic of screening effect due to parallel conducting channels in the wraparound CNTFET with multi-CNT channels. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 5. Schematic presentation of fringing capacitance and associated device parameters of the CNTFET. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 6. Conceptual illustration of gate-to-drain/source capacitance of the CNTFET. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 7. Model of the CNTFET with multi-CNT channels created by COMSOL and used in 3-D simulation. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 8. Variation of voltage in the wraparound gate CNTFET with multi-CNT having 25-nm pitch as obtained from 3-D simulation using the FEM. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 9. Three-dimensional simulation result of voltage variation in the CNTFET having 15-nm pitch using FEM. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 10. Gate-to-channel capacitance of end CNT for a different gate dielectric. The proposed FEM model is in excellent agreement with the analytical model. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 11. Gate-to-channel capacitance of mid CNT for a different gate dielectric. The proposed FEM model is in excellent agreement with the analytical model. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 12. Gate-to-channel capacitance of end CNT as a function of pitch. Improvement over the top-gate device and agreement between the FEM and analytical models is apparent. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 13. Gate-to-channel capacitance of mid CNT as a function of pitch. Improvement over the top-gate device and agreement between the FEM and analytical models is apparent. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 14. Variation of gate outer fringe capacitance of end CNT with S/D extension length. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 15. Variation of gate outer fringe capacitance of mid CNT with S/D extension length. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "FEM Model of Wraparound CNTFET With Multi-CNT and Its Capacitance Modeling," in IEEE Transactions on Electron Devices, vol. 60, no. 1, pp , Jan doi: /TED Fig. 16. Variation of gate-to-S/D capacitance with S/D extension length. Finite Element Model of Wraparound CNTFET Using Comsol
M. R. K. Akanda and Q. D. M. Khosru, "Analysis of output transconductance of FinFETs incorporating quantum mechanical and temperature effects with 3D temperature distribution," 2011 International Semiconductor Device Research Symposium (ISDRS), College Park, MD, 2011, pp doi: /ISDRS FinFET Transconductance Including Temperature and Quantum Mechanical Effect
M. R. K. Akanda, R. Islam and Q. D. M. Khosru, "A physically based compact model for FinFETs on-resistance incorporating quantum mechanical effects," International Conference on Electrical & Computer Engineering (ICECE 2010), Dhaka, 2010, pp doi: /ICELCE Fig. 18. Different planes (A and B) for contact resistance Fig. 17. Different parts of on resistance in FinFET FinFET On-Resistance
M. S. Islam and M. R. K. Akanda, "3D temperature distribution of SiC MESFET using Green's function," International Conference on Electrical & Computer Engineering (ICECE 2010), Dhaka, 2010, pp doi: /ICELCE Fig. 19. Cross section of SiC MESFET (side view) Fig. 20. Mobility versus temperature curve Temperature Effect in SiC MESEFET
M. S. Islam, M. R. K. Akanda, S. Anwar and A. Shahriar, "Analysis of resistances and transconductance of SiC MESFET considering fabrication parameters and mobility as a function of temperature," International Conference on Electrical & Computer Engineering (ICECE 2010), Dhaka, 2010, pp doi: /ICELCE Fig. 21. Specific on-resistance (approximated) versus channel doping concentration without considering (Dashed Line) and considering (solid line) temperature effect Fig. 22. The I-V Characteristics of 4H-SiC MESFET with W=150 m and L=1 m at T=300K for Ideal condition (Solid Line), Channel Length Modulation Effect (Dash Dot Line) and Self Heating effect (Dashed Line) Change in Mobility and Resistance of SiC MESFET with Temperature and Doping
M. S. Islam, M. R. K. Akanda, S. Anwar and A. Shahriar, "Analysis of resistances and transconductance of SiC MESFET considering fabrication parameters and mobility as a function of temperature," International Conference on Electrical & Computer Engineering (ICECE 2010), Dhaka, 2010, pp doi: /ICELCE Fig. 23. The Drain to source resistance, Rds versus Drain voltage Vds at T=300K for Ideal condition (Solid Line), Channel Length Modulation Effect (Dash Dot Line) and Self Heating effect (Dashed Line) Fig. 24. The Source-Drain Resistance for different Physical and fabrication parameters for T=300K (Dashed Line) and T=340K (Solid Line) Change in Mobility and Resistance of SiC MESFET with Temperature and Doping