1. Department of Electronics
Nanoelectronics 01
Atsufumi Hirohata
Department of Electronics
13:00 Monday, 16/January/ (P/T 006)

2. Go into Nano-Scale 10 -3 Micron-scale Lateral Size [m] 10 -6
Vacuum tube (~ 20 cm) † †
Transistor (~ 1 cm) ‡
‡ S. M. Sze, Physics of Semiconductor Devices
(John Wiley, New York, 1981).
10 -3
Cassette tape
(~ 600 µm)
Human hair (~ 50 µm)
Transistor
(~ 50 µm) †
Video cassette tape
(~ 19 µm)
Micron-scale *
Red blood cell (~ 7 µm) *
Floppy disc
(~ 1.5  190 µm)
Lateral Size [m]
10 -6
MO disc
(~ 290  1000 nm)
Sub-Micron-scale
Processor ‡
(~ 45 nm) **
Virus
(~ 80 nm) **
HDD
(~ 25  200 nm)
Nano-scale
DNA (width ~ 2 nm) ***
***
Carbon nano-tube (width ~ 1 nm)
10 -9
Quantum-scale
Hydrogen atom (~ 0.1 nm)

3. Nanoelectronics Electronics Materials Science Electron transport
Semiconductors
Magnetism
Ferromagnets
Superconductors
Organic materials
In conclusion, we observed efficient spin filtering in Schottky diodes at room temperature. This depends on the orientation of the photon helicity and the FM magnetization.
Using spin valve structures, we demonstrated that spin filtering occurs in ballistic regions.
Combining these results, ballistic spin filtering was achieved at room temperature.
Physics
Electromagnetism
Quantum mechanics

4. Contents of Nanoelectronics
Lectures : Atsufumi Hirohata 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)

5. 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).
G. L. Squires, Problems in Quantum Mechanics (Cambridge University Press,
Cambridge, 1995).
provides broad problems with solutions.
Lecture notes / slides :

6. 01 Micro- to Nano-Electronics ?
Device miniaturisation
Micron / nanometre
Nanofabrication
New functionality
Electron transport

7. Miniaturisation of Data Processors*

8. 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 ! *

9. Current Semiconductor Technology
45-nm rule :
Nanofabrication method :
0.9 nm thick * **

10. Roadmap for Si-Based Devices
* V. V. Mitin, V. A. Kochelap and M. A. Stroscio, Introduction to Nanoelectronics (Cambridge University Press, Cambridge, 2008).

11. Latest Chips

12. Cross-Section of Latest Chips

13. Advantages of Latest Chips

14. Improvements by Latest Chips

15. 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 ~)

16. How Does a Recording Head Look Like ?
Recording media …
Recording head …
Read / write head
Lubricant ~ 1 nm
Carbon coating < 15 nm
Magnetic media ~ 30 nm
Chromium buffer ~ 50 nm
Nickel buffer ~ 10 m
Metalic/glass substrate
Arm
Recording head
Disc rotation
Configurations of a platter :
If the head is a jumbo jet (B747)...
Height 1.5 mm
0.15 mm
0.5 mm
1 mm N S

17. Development of a HDD Recording density increases at 100% / year :
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
× 18,000

18. Current Magnetic Recording Technology
Anisotropic to Giant magnetoresistance :
Longitudinal to perpendicular recording : *

19. Miniaturisation in Magnetic Recording Technology
Size evolution of a recording head in a HDD :

20. Advancement in Communication Technologies
Similar to Moore’s law :
Data transfer becomes faster.
LAN
Inside a PC
Network

21. Advantages of Nano-Scale Miniaturisation
From microelectronics to nanoelectronics :
Reduction of effective electron paths
Reduction of electron scattering
Decrease in an acceleration voltage
Decrease in device size
Faster operation
Lower power consumption
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

22. Electron Transport in a Nano-Device
Diffusive transport :
Ballistic transport :
Electron scattering
 Electrical resistivity
Negligible electron scattering
 Negligible electrical resistivity
 Transport in a vacuum
W > F
W ~ F
L ~
L >
: electron mean free path (~ 40 nm for RT)
F : Fermi wave length (~ 1 nm)
Hot-electron

23. 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).