Nanoelectronics: AdvanNano-Scale Semiconductor Devices” By Dr. G. S. Virdi Ex-Chief Scientist, CSIR-Central Electronics Engineering Research Institute (CEERI), Pilani, India

This lecture on Nanoelectronics is presented by Dr. G. S. Virdi, Ex-Chief Scientist, CSIR–Central Electronics Engineering Research Institute (CEERI), Pilani, India, with extensive experience in Microelectronics and Nanoelectronics research. The content covers the fundamentals of nanoscale device physics, the evolution of semiconductor technology, quantum-effect devices, and modern nanoelectronic components such as Single Electron Transistors (SETs), quantum dots, and molecular devices.

The lecture highlights the importance of nanotechnology in advancing the electronics industry, enabling ultra-compact, high-performance devices used in computing, communication, medical instrumentation, and industrial systems. It also discusses fabrication challenges, emerging applications, and future research opportunities in the field.

This lecture will be highly beneficial for engineering and science students (M.Sc., M.Tech.), research scholars, and professionals working in micro- and nano-scale semiconductor device technologies.

1. NANOELECTRONICS
.
Dr.G.S.Virdi
Ex.ChiefScientist
CSIR-Central Electronics Engineering Research Institute
Pilani—33303 1,India

2. Nano:
It is derived from a greek word
NANOSwhich meansDWARF .
In the metric system, nano refers
to 10
-9
or 1/1,000,000,000 of one
meter.
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3. Nanoelectronics:
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4. WhatisNanoelectronics?
•Art and science of manipulating matter at the nanoscale.
•One of the major technologies of Nanotechnology. Plays vital role in
the field of engineering and electronics.
•Makes use of scientific methods at atomic scale for developing the
Nano machines.
•Main target is to reduce the size, risk factor and surface areas of the
materials and
molecules.
•The Nanotechnology field has been the subject of intense focus,
particularly from the viewpoint of the electronics industry.
•It is implied to be used as the next-generation approach towards
manufacture of MEMS, microprocessors, optical switching and
several other electronic components.
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5. WhyNanoelectronics?
•Todaymicroelectronicsusedandsolvesmostproblems.
•Nanoelectronicdevicesareverysmalldevicesandovecomelimits
onscalability.
•Nanoelectronicsisnotonlyaboutsizebutalsophenomena,
mechanism,etc.
•Wideopenfieldwithvastpotentialforbreakthroughscoming
fromfundamental
research.
•Overcome2demerits:
Physicalsize
CostofICfabrication
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6. Nanoelectronics:
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7. Nanoelectronics:
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8. These days, nanotechnology has a wide area of applications.
Some of its applications are in:
Biotechnology
Electronics
Chemistry
Computing
Medicine
Physics
and many more…..
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9. IndustrialApplications
•The technology made the devices very light making the product easy to carry or
move and at the same time it has reduced the power requirement.
•Some Consumer Products which are using Nanotechnology:
Computer Hardware
Display Devices
Mobile & Communication Products
Audio Products
Camera & Films
•Electronics Examples:
Single-Electron Transistors
Controlled electron tunneling to amplify current
Resonance Tunneling Device
Quantum device use to control current
•Canalsobeusedtocreatedevicesknownasnanoelectromechanicalsystemsor
NEMS,whicharerelatedtomicroelctromechanicalsystemsorMEMSthatare
practicallyusedtomakeelectronicscomponents.
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10. NanotechnologyforMolecularDevices
•Reducing size of electronics is the need of era and this can be achieved with the
help of molecules that can be used in active devices.
•These molecules behave as diodes or programmable switches that make
connections between wires and consume less current.
•Thousands of molecules can be sandwiched between two crossing micro-scale
wires to create an active devices. Since molecular devices fit between the wires,
large area savings could be achieved.
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11. NanotechnologyinElectronics
•Electrodes made from nanowires enable flat panel displays to be flexible as well as
thinner than current flat panel displays.
•Nanolithography is used for fabrication of chips.
•The transistors are made of nanowires, that are assembled on glass or thin films of
flexible plastic.
•E-paper, displays on sunglasses and map on car windshields.
•A memristor can be used as a single-component memory cell in an integrated circuit.
• By reducing the diameter of the nanowires, researchers believe memristor
memory chips can achieve higher memory density than flash memory chips.
•Magnetic nanowires made of an alloy of iron and nickel are being used to create
dense memory devices
•ChipsproducedbyIntelbefore“i”seriesprocessorswerebetween65nm-45nmand
laterwiththehelpofnanotechnolgy22nmchipsweremadewhichitselfisamilestone
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12. Nanoelectronics
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13. Nanoelectronics:
Nanoelectronics generally refers to semiconductor devices
that have been shrunk to the nanoscale.
It can also defined as the use of NANOTECHNOLOGY on
electronics components especially on TRANSISTORS.
Present days transistors are also in the range of 45 nm, 32 nm,
and 22 nm, but still they are not included in the category of
nanoelectronics because nanoelectronics often refer to transistor
devices that are so small that inter-atomic interactions and
quantum mechanicalproperties need to be studied
extensively….
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14. History
•The first ever concept was presented in 1959 by the famous professor of physics
Dr. Richard P.Feynman.
•Invention of the scanning tunneling microscope in 1981 and the discovery of
fullerene(C60) in 1985 lead to the emergence of nanotechnology.
•The term “Nano-technology" had been coined by Norio Taniguchi in 1974.
•Theearly2000salsosaw the beginnings of
commercial applicationsof nanotechnology, although these
were limited to bulk application of nanomaterials.
•The number of transistors on a chip will approximately double every 18 to 24
months (Moore’s Law)-This law has given chip designers ideas to incorporate
new features on ICs.
•Moore's Law works largely through shrinking transistors that carry electrical
signals, so the designers can squeeze more transistors into a chip, leading to the
idea of nanoelectronics.
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15. Moore’s Law:
According to this law, "The number of transistors that can be
placed inexpensively on an integrated circuit doubles
approximately every two years. This trend has continued for
more than half a century and is expected to continue until at
least 2015 or 2020.”
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16. In 1965, Gordon Moore sketched out his prediction of the pace of
silicon technology. Decades later, Moore’s Law remains true, driven largely by
Intel’s unparalleled silicon expertise.
Moore’s Law
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17. ▶Nanoelectronics results in the reduction of size and scale of
the machine with the help of complex integration of circuits
and chips
▶It is not only about size but also phenomena, mechanism,
etc.
▶It is a wide open field with vast potential for breakthroughs
coming from fundamental research.
Nanoelectronics:
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18. Nanoelectronics devices are of two types:
Solid-state quantum-effect nanoelectronic devices
Quantum Dots (or "artificial atoms"),
Resonant Tunneling Devices, and
Single-Electron Transistors (SETs).
Molecular electronic devices
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19. Single Electron Transistor (SET):
It can be defined as a
switching device that uses
controlled electron
tunneling to amplify current
or as a device that exploits
the quantum effect of
tunneling to control and
measure the movement of
single electrons…
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20. Formation of SET:
A tunnel Junction and its schematic diagram
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21. G.S.VIRDI

22. The SET is made by placing 2 tunnel junctions in series.
The 2 tunnel junction create what is known as a “Coulomb
Island”that electrons can only enter by tunneling through one
of the insulators.
This device has 3 terminals like the FETs.
The cap may seem like a third tunnel junction, but is much
thicker than the others so that no electrons could tunnel
through it.
The cap simply serves as a way of setting the electric charge
on the coulomb island.
Formation of SET:
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23. Working:
In SET, the charge flows through the island in
quantized units.
For an electron to hop onto the island, its energy must
be greater than the COULOMB ENERGY.
When both the gate and bias voltages are zero,
electrons do not have enough energy to enter the island
and current does not flow.
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24. Working Contd…
When the bias voltage between gate and source is increased,
Electrons pass through the junction as their energy now
reaches the Coulomb Energy.
This effect is known as the Coulomb blockade,and the
critical voltage needed to transfer an electron onto the island,
equal to e/2C, is called the Coulomb gap voltage.
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25. For Function:
Capacitance of the junction must be less than 10
-17
Farads.
Size must be smaller than 10 nm.
To make a significant contribution in coulomb energy,
the wavelength of the electron must be of the size of a dot.
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26. The Coulomb Island
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27. Application of SET:
Supersensitive Electrometer
DC Current Standards
Temperature Standards
Detection of Infrared Radiation
Voltage State Logics
Charge State Logics
Programmable Single Electron Transistor Logic
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28. Advantages:
Small size
Low energy consumption
High sensitivity
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29. Disadvantages:
Lithography Techniques
Background Charge
Co tunneling
Room Temperature Operation
Linking SETs with the Outside Environment
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30. Conclusion:
Single Electronic Transistor (SET) has proved their value as tool
in scientific research. Researchers may someday assemble these
transistors into molecular versions of silicon chips , but there are
still formidable hurdles to cross.
SETs could be used for memory device, but even the latest SETs
suffer from “offset charges”, which means that the gate voltage
needed to achieve maximum current varies randomly from device
to device. Such fluctuations make it impossible to build complex
circuits, but the future does look bright for these devices.
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31. Thank You…