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Introduction Electronics without silicon is unbelievable. Disadvantages when used in power electronics application, such as: 1) bulk in size 2) slow operating speed, etc.

Contd … :

Contd … Pure Silicon and Germanium are semiconductors in normal temperature. In earlier days they were used widely for manufacturing of electronic components. Fig: Part of mordern periodic table

Contd …:

Contd … Research people found that carbon has more advantages than silicon. Using carbon as the manufacturing material, we can achieve smaller, faster and stronger chips.

What is diamond chip?:

What is diamond chip? In a single definition, Diamond Chip or Carbon Chip is an Electronic Chip manufactured on a diamond structure Carbon wafer

How is it possible ?:

H ow is it possible ? Diamond structural carbon is non conducting in nature. To make it conducting, doping process is performed. Boron-- as the p-type. Nitrogen--as the n-type.


i nvention Developed by Nippon Telegraph and Telephone Corporation (NTT), Japan, 1991. A diamond semiconductor operates on a 81 GHz frequency, and is more than twice the speed of earlier devices.

Some facts…:

S ome facts… Carbon is not a semiconductor. Some of the carbon allotropes acts as semiconductor. The functionality of graphene. The functionality of nanotubes. Fig: Carbon atom.


Graphene. allotrope of carbon. structure is one-atom-thick planar sheets of sp 2 -bondage densely packed in a honeycomb crystal lattice. Properties: It has a remarkably high electron mobility at room temperature. Graphene structure can be doped easily. Can be converted back to its undoped. Fig : Graphene sheet in planer structure.

What is carbon nanotube?:

What is carbon nanotube? Just fold the graphene sheet into a tube like structure It is a nanosize cylinder of carbon atoms. It has less than one nanometer diameter. Fig:Carbon nanotubes made step by step. Fig :View of CNT.

Types of nanotubes:

Types of nanotubes Fig: All SWNT structures. Fig:multiwalled

How Nanotubes act as semiconductors?:

How Nanotubes act as semiconductors? For a given (n,m) nanotube If n=m then nanotube is metallic; If n-m is multiple of 3 then the nanotube is a semiconductor . Thus all armchair nanotubes (n=m), are metallic; and some zigzag and chiral types nanotubes are semiconducting. e.g.: zigzag : (3,0); (6,0) etc. chiral : (5,2); (7,1) etc. Fig:graph.

Why the name DIAMOND CHIP?:

Why the name DIAMOND CHIP? Lonsdaleite is an sp3 bondage allotropic form of carbon i.e. 3-dimentional CNT. Crystal structure of Lonsdaleite looks exactly like diamond. Fig (a): Lonsdaleite Structure . (b):crystal structure of Lonsdaleite. (a) (b)

Properties of CNT :

Properties of CNT Properties 1 Strength 2 Hardness 3 Electrical 4 Thermal 5 One-dimensional transport


Properties… HARDNESS : It can withstand a pressure up to 24GPa without deformation. STRENGTH : Carbon nanotubes are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively.


Properties… ELECTRICAL : High electrical conductivity (10 -6 ohm). Do not suffer from electro migration or atomic diffusion and thus can carry high current densities (10 7 -10 9 A/cm 2 ),which is 1000 times that of copper. Both metal and semiconductor can be formed.


Properties… THERMAL : The temperature stability of carbon nanotubes is estimated to be up to 2800 °C in vacuum and about 750 °C in air. ONE DIMENTIONAL TRANSPORT : Because of the nanoscale dimensions, electrons propagate only along the tube's axis. Carbon nanotubes are frequently referred to as “one-dimensional” Fig: Flow of electrons In Carbon Nanotubes.

CNT can form ideal diode.:

CNT can form ideal diode. We placed two separate gates underneath a single-walled nanotube Biasing one gate with a negative voltage and the other with a positive voltage, a p-n junction ideal diode is formed. Fig :showing ideal diode charecteristics.

A brief idea about carbon transistors:

A brief idea about carbon transistors Much smaller components are possible. Conducts electricity faster as electrons travels through straight line without scattering. Ultimately we get faster and more efficient electronic component.

How nanotubes are useful in digital logic?:

How nanotubes are useful in digital logic? Simple inverter device consists of a nanotube FET and a large bias resistance: which converts a high input voltage to a low one –i.e., "one" to "zero" - and vice versa. By adding an extra FET in parallel, the researchers made a NOR gate. This device needs two "zero" inputs to give a "one" output, or two "ones" to give a "zero”.


ADVANTAGES Smaller components are possible. It works at higher temperature. Faster than silicon chips. Larger power handling capacity. ..OF DIMOND CHIP OVER SILICON CHIP

Carbon nanotube Applications :

Carbon nanotube Applications Information and Communications, Materials and Manufacturing, Biomedical, Energy and Environmental, Transportation Consumer goods.


LIMITATIONS Much more expensive than silicon. Doping process is very hard to perform due to the diamond structure , than in silicon.

Conclusion :

Conclusion Thus diamond chip replaces the need of silicon in every aspect in future generation.


references http://www.authorstream.com http://www.seminarprojects.com http://www.wikipedia.com http://www.jpl.nasa.gov http://www.google.com http://cnx.org/content/m22580/latest http://www.infoworld.com/t/platforms/study-carbon-nanotubes-make-best-semiconductors-487 http://ieeexplore.ieee.org



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