1. G RAPHENE N ANORIBBON T UNNEL TRANSISTORS GUIDED BY:Ms.ANITTA MATHEW Asst.Professor ECE Dept. BLESSY JOSEPH S7 ECA Roll No:28

2. G RAPHENE  Crystal structure of carbon.  Arranged in flat plane, as honeycomb lattice.  Band gaps-varying inversely with the width.  Isolated in 2004.

3. F EATURES OF GRAPHENE  Ultra thin body…  Excellent thermal conductivity…  High carrier mobility, same for electrons and holes….  transparent…

4. G RAPHENE N ANORIBBON (GNR)  Thin strip.  Band gap.  Armchair & zigzag.

5. T RANSISTOR - MATERIALS  Silicon  Germanium  Indium Gallium Arsenide  Indium Phosphide  Indium Arsenide  Carbon Nanotube etc..

6. ON STATE CURRENT

7. GNR TFET  December 2008 : IBM  Why TFET ; low subthreshold swing, low off state leakage.  Why GNR ; increase on state tunneling current : -symmetric band structure -monolayer thin body -light effective mass

8. NMOSFET Vs GNR TFET

9. S TRUCTURE Oxide thickness =1.5 nm;channel length=30nm, doping density= 0.01 dopant/atom

10. W ORKING  Tunneling-penetration of particle through the barrier  Band to band tunneling  Minimum band gap

11. A DVANTAGES  Higher speed  Lower dynamic power  Lower off state power dissipation  Room temperature  Very low supply voltage  Higher packing density  Control bandgap  Excellent conductivity

12. L IMITATIONS  Lower on/off ratio  Ambipolar I-V characteristics  Edge effects

13. I ON – I ON /I OFF CHARA

14. A MBIPOLAR I-V CHARACTERISTICS

15. A SYMMETRIC SOURCE - DRAIN DOPING

16. C ONCLUSION :  Graphene has got more advantages than any other semiconductor.  GNRTFET- low power application  Making tomorrow's computer- pencil trace.  GNR TFET – back bone of modern nanoelectronics. Past Present Quantum computer

17. R EFERENCES :  Base paper: ‘Graphene Nanoribbon tunnel transistors’- Qin Zhang,Tian Fang,Huili Xing, Alan Seabaugh,and Debdeep Jena, IEEE electron device letters, 2008.  Computational Study of Tunneling Transistor Based on Graphene Nanoribbon -Pei Zhao, Jyotsna Chauhan, and Jing Guo, Department of Electrical and Computer Engineering,University of Florida  Graphene Tunneling FET and its Applications in Low-power Circuit Design- Xuebei Yang,Jyotsna Chauhan, Jing Guo,Kartik Mohanram-Dept of Electrical and Computer Engineering, Rice University, Houston

18.  Solid State Electronic Devices –Ben G.Streetman  www.itrs.net.  www.ieee.org  www.wikipedia.org.

19. THANK YOU ALL FOR YOUR VALUABLE TIME…..