A presentation on the comparative study conducted on Carbon Nanotube MOSFET, Silicon Nanowire MOSFET and Single Gate MOSFET

1. A Comparative Study on Carbon
Nanotube MOSFET, Silicon Nanowire
MOSFET and Single Gate MOSFET

2. To simulate different characteristics of single gate MOSFET,
silicon nanowire MOSFET and carbon nanotube
MOSFET using the simulation tool FETToy in nanohub.
To compare between the three technologies in terms of-
 Drain current VS gate voltage relation.
 Drain current VS drain voltage relation.
 Mobile charge VS gate voltage relation.
 Quantum capacitance VS gate voltage relation.

3. Earlier approach
Analog switch with 4
terminal MOSFET
structure [1]
N-type and p-type
Gate voltage controls the
switching
Electrons have mobility 3
times the holes
Fig: single gate MOSFET [2]

4. Quantum wire structure
Wire diameter= 10^-9 nm
Mobility of electrons is
controlled by the
electrostatic potential
applied at gate contact.
‘Field effect’ operation [3]
Ballastic movement of
electrons Fig: silicon nanowire MOSFET [2]

5. Advanced technology
Graphene role as
nanotube
Single or an array of tubes
as the channel in FET
Band gap is directly
affected by chirality and
diameter. [4]
Low power device, faster
switching Fig: carbon nanotube MOSFET

6. Single gate MOSFET-
 gate oxide thickness= 1.5 nm
 gate insulator dielectric constant=3.9
 effective mass ratio=.19
 valley degeneracy=2
 body thickness=10nm.
 Silicon nanowire MOSFET-
 gate insulator dielectric constant=3.9
 transport effective mass ratio=.19
 valley degeneracy=2 and nanowire diameter=1 nm

7. Carbon nanotube MOSFET-
 nanotube diameter=1 nm
 gate insulator thickness=1.5 nm
 gate insulator dielectric constant=3.9

8. gate control constant β= .88
drain control constant α= .035
Temperature= 300K
Gate voltage= 0 t0 2 volts
Drain voltage= 0 to 2 volts
Bias points= 12

9. Carbon nanotube
MOSFET(lowest, saturates
at 1 µA)
single gate MOSFET silicon nanoribon MOSFET

10. Carbon nanotube MOSFET single gate MOSFET
(minimum slope)
silicon nanoribon MOSFET
(maximum slope)

11. Carbon nanotube MOSFET
(lower mobile charge
density
single gate MOSFET silicon nanoribon MOSFET

12. Carbon nanotube
MOSFET(lowest quantum
capacitance)
single gate MOSFET silicon nanoribon MOSFET

13. characteristics Carbon nanotube
MOSFET
Silicon nanowire
MOSFET
Single gate MOSFET
ID VS VG low high high
IDVS VD Moderate slope Minimum slope Maximum slope
Mobile charge density
VSVG
low high high
Quantum capacitane
VS VG
minimum high high

14. Carbon nanotube MOSFET has moderate slope as found from
ID VS VD characteristics. So, it can be used for amplification
purpose as well where as other two devices are limited to
mostly switching purposes. Cnt MOSFET has low quantum
capacitance. So drain voltage has less effect on the
performance of the IC that leads to drain control constant
value, α=.035 which is very close to the ideal case (for ideal
case, α=0.
So, based on the simulated results we can come to the conclusion
that carbon nanotube MOSFET is better for nanoelectronic
design among the three types of devices considered here .

15. [1] Uhua Cheng, Chenming Hu (1999). "§2.1 MOSFET c
lassification and operation".MOSFET modeling & BSIM3
user's guide. Springer. p. 13. ISBN 0-7923-8575-6.
[2] www.nanohub.org/simulation/FETToy
[3] Holmes, Justin D.; Johnston, Keith P.; Doty, R. Christopher and
Korgel, Brian A.,” Control of thickness and orientation of
solution-grown silicon nanowires.” Science (2000), 287(5457),
1471-1473
[4] Dekker, Cees; Tans, Sander J.; Verschueren, Alwin R. M. (
1998). "Room-temperature transistor based on a single carbon
nanotube", Nature 393 (6680):49.Bibcode:1998Natur.393...49
T. doi:10.1038/29954