NANO ELECTRONICS

NANO ELECTRONICS

ABSTRACT

Gordon Moore, one of the founders of INTEL claimed that “the number of transistors on a single silicon chip doubles every 18 to 24 months” which famously came to be known as Moore’s law. In accordance with this law till now we have been able to fabricate circuits on the micro level and there is no reason why miniaturization should stop at this level. But after a certain period of time the current technology will no longer be feasible as our basic concepts of electronics, fabrication and conduction breakdown at the nano level. Hence there is a need to bring in a new technology, which can revolutionize the entire field of electronics.

This is where steps in the concept of molecular electronics and carbon nanotubes. In the report we have mainly stressed on nanotubes because of the vast research that has taken place on them as well as the amazing properties that they exhibit. Molecular electronics encompasses biology, chemistry, computing, electronics, physics, quantum phenomenon, each subject with it’s own methodology and jargon.

Let us see a few startling facts about nanotechnology. Manufactured products are made from atoms. The properties of those products depend on how those atoms are arranged. If we rearrange the atoms in coal, we get diamonds. If we rearrange the atoms in sand (and add a pinch of impurities) we get silicon chips used in computers.

At the same time, when you are going to the nano-scale there will be many gray areas, many surprising things that might surface. Firstly at the molecular level the concept of gravity ceases to exist and classical mechanics is replaced by quantum mechanics. Also the exact behavior of electrons cannot be predicted at this level. Secondly the concept of temperature is known to breakdown at atomic level. Hence the physical properties of the system can be unpredictable.

The discovery of carbon nanotubes heralded a new era of scientific discovery that included the promise of ultra-sensitive bomb detectors, damage proof cars and super-fast computer memory chips. The nano tubes have many extraordinary properties like high elasticity and tensile strength, excellent heat conductivity and electrical properties. What remains to be done is their proper application in electrical circuits.

Carbon nanotubes are different: first they will bend over to surprisingly large angles, before they start to ripple and buckle, and then finally develop kinks as well. The amazing thing about carbon nanotubes is that these deformations are elastic - they all disappear completely when the load is removed.

To see how these properties might be useful, imagine owning a BMW car made from carbon nanotubes and being unlucky enough to crash into a wall. Due to the high force of the impact, the nanotubes would bend and then buckle, squeezing your BMW into the shape of something like a Volkswagen Beetle. This would happen over a relatively long distance, which would provide an effective "crunch zone". Moreover, after the crash all the buckles and kinks would unfold and your BMW would "reappear" as if nothing had happened! To be completely safe, however, the nanotubes would have to be combined with energy-absorbing materials, otherwise the collision between the car and the wall would be completely elastic and you would rebound from the wall with the same speed as you hit it!

Now to develop nano electronic devices we need some instrument to obtain atomic-scale images of metal surfaces and to move and position individual atoms. The Scanning Tunneling Microscope (STM) is one such device and it has played a pivotal role in the research and development of nano-devices. The report gives an in-depth analysis of its structure, working and applications.
Finally it would not be wrong to say that the following text is just a tip of the iceberg. Tremendous amount of research is currently being pursued in this direction and one just gets the feeling that we are on the brink of a NANO-REVOLUTION. And that day is not far off when we will have yet another branch in engineering-NANOELECTRONICS.

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