Transcript nanoelec01_introduction_transport.ppsx

Nanoelectronics
01
Atsufumi Hirohata
Department of Electronics
13:00 Monday, 16/January/2017
(P/T 006)
Go into Nano-Scale
10
-3
Transistor (~ 1 cm) ‡
Vacuum tube (~ 20 cm) †
Cassette tape
(~ 600 µm)
Human hair (~ 50 µm)
Transistor
(~ 50 µm) †
Lateral Size [m]
Micron-scale
Video cassette tape
(~ 19 µm)
Red blood cell (~ 7 µm) *
Floppy disc
(~ 1.5  190 µm)
10 -6
Sub-Micron-scale
Virus
(~ 80 nm) **
MO disc
(~ 290  1000 nm)
Processor ‡
(~ 45 nm)
HDD
(~ 25  200 nm)
Nano-scale
DNA (width ~ 2 nm) ***
10 -9
Carbon nano-tube (width ~ 1 nm)
Quantum-scale
* http://www.esa.int/esaKIDSen/SEMOC68LURE_LifeinSpace_1.html
** http://www.guardian.co.uk/pictures/image/0,8543,-11404142447,00.html
*** http://www.wired.com/medtech/health/news/2003/02/57674
Hydrogen atom (~ 0.1 nm)
†
‡
http://www.wikipedia.org/
S. M. Sze, Physics of Semiconductor Devices
(John Wiley, New York, 1981).
Nanoelectronics
Electronics
Materials Science
• Electron transport
• Semiconductors
• Magnetism
• Ferromagnets
• Superconductors
• Organic materials
Physics
• Electromagnetism
• Quantum mechanics
Contents of Nanoelectronics
Lectures : Atsufumi Hirohata ([email protected], P/Z 019)
Electrical transport in nano-scale (Weeks 2 ~ 10)
[13:00 Mons. (P/T 006) & 11:00 Weds. (D/L 036)]
I. Introduction to nanoelectronics (01)
II. Electromagnetism (02 & 03)
III. Basics of quantum mechanics (04 ~ 06)
IV. Application of quantum mechanics (07, 10, 11, 13 & 14)
V. Nanodevices (08, 09, 12, 15 ~ 18)
Workshops : (1/2 marks in your assessment)
Equation solving in quantum physics (Week 2, 4, 6 & 8)
[17:00 Fris. (V 123 & P/T 007)]
Submit your answers to the General Office by 12:00 on the following Fris.
Examination : (1/2 marks in your assessment)
Closed book exam (Equation solving + Essay)
References
General textbooks in nanoelectronics :
K. Goser, P. Glosekotter and J. Diestuhl, Nanoelectronics and Nanosystems
(Springer, Berlin, 2004).
covers all the topics in the field.
V. V. Mitin, V. A. Kochelap and M. A. Stroscio, Introduction to Nanoelectronics
(Cambridge University Press, Cambridge, 2008).
focuses on semiconductor nanoelectronics and nanodevices.
Douglas Natelson, Nanostructures and Nanotechnology (Cambridge University
Press, Cambridge, 2016).
focueses on nanoelectronic devices.
General textbooks in quantum mechanics :
R. Eisberg and R. Resnick, Quantum Physics of Atoms, Molecules, Solids, Nuclei
and Particles (John Wiley, New York, 1985).
covers all the topics in the field.
G. L. Squires, Problems in Quantum Mechanics (Cambridge University Press,
Cambridge, 1995).
provides broad problems with solutions.
Lecture notes / slides : http://www-users.york.ac.uk/~ah566/lectures/lectures.html
01 Micro- to Nano-Electronics ?
Device miniaturisation
•
Micron / nanometre
•
•
Nanofabrication
•
New functionality
•
Electron transport
Miniaturisation of Data Processors
* http://www.wikipedia.org/
Miniaturisation and Integration in Semiconductor Devices
Moore’s law :
“The number of transistors on a chip will double every 18 months.” (1965)
10 years later he revised this to “every 24 months.”
 The development speed becomes even faster !
* http://www.intel.com/
Current Semiconductor Technology
45-nm rule :
Nanofabrication method :
0.9 nm thick
* http://www.intel.com/
** http://www.kodak.com/
Roadmap for Si-Based Devices
* V. V. Mitin, V. A. Kochelap and M. A. Stroscio, Introduction to Nanoelectronics (Cambridge University Press, Cambridge, 2008).
Latest Chips
Cross-Section of Latest Chips
Advantages of Latest Chips
Improvements by Latest Chips
Increase in Recording Density of Hard Disc Drives
Similar to Moore’s law :
Areal density in a hard disc drive (HDD) will double every 36 months. (~ 1992)
After giant magnetoresistance (GMR) implementation,
it will double less than every 20 months. (1992 ~)
How Does a Recording Head Look Like ?
Recording media …
Recording head …
Read / write head
Configurations of a platter :
Recording head
If the head is a jumbo jet (B747)...
Arm
Lubricant ~ 1 nm
Carbon coating < 15 nm
Magnetic media ~ 30 nm
Chromium buffer ~ 50 nm
Nickel buffer ~ 10 m
Metalic/glass substrate
Disc rotation
N
S
0.15 mm
0.5 mm
1 mm
Height 1.5 mm
Development of a HDD
Recording density increases at 100% / year :
× 18,000
First HDD in the world :
RAMMAC 305 (1956, IBM)
60 cm platter × 50 = 4.4 MB
10 Mbit / inch2
Current HDD :
MK2035GSS (2006, Toshiba)
6.4 cm platter × 2 = 200 GB
178.8 Gbit / inch2
Current Magnetic Recording Technology
Anisotropic to Giant magnetoresistance :
Longitudinal to perpendicular recording :
* http://www.hitachigst.com/
Miniaturisation in Magnetic Recording Technology
Size evolution of a recording head in a HDD :
Advancement in Communication Technologies
Similar to Moore’s law : Data transfer becomes faster.
LAN
Inside a PC
Network
Advantages of Nano-Scale Miniaturisation
From microelectronics to nanoelectronics :
 Reduction of effective electron paths
 Reduction of electron scattering
 Faster operation
 Decrease in an acceleration voltage
 Lower power consumption
 Decrease in device size
 Higher integration / lower cost
 More complicated fabrication processes
 Higher fabrication cost
 Larger distributions in device properties
 Leakage currents (insulator < 1nm thick)
 No electron confinement (path < 10 nm thick)
 Joule heating
 Need to be solved in Nanoelectronics
• Electromagnetism
• Quantum physics
• Nano-device fabrication
Electron Transport in a Nano-Device
Ballistic transport :
Diffusive transport :
Electron scattering
Negligible electron scattering
 Electrical resistivity
 Negligible electrical resistivity
 Transport in a vacuum
W > F
W ~ F
L~
L>
: electron mean free path (~ 40 nm for Cu @ RT)
F : Fermi wave length (~ 1 nm)
Hot-electron
Electron Transport in Nano-Structures
4 fundamental nano-device structures :
2D
Ultrathin film (quantum well)
Superlattice (multilayer)
1D
0D
Quantum wire (nano-wire)
Quantum dot (nano-dot)
* H. Sakaki and N. Yokoyama, Nanoelectronics (Ohm-sha, Tokyo, 2004).