NANOTECHNOLOGY Miss.M.S.Patil Mr.V.R.PatilLecturer IT Deptt. Lecturer E&TC Deptt.RCPIT,Shirpur RCPIT,ShirpurMb.-9373145351 Mb.-9373235207

Patilmanisha2003@yahoo.co.in patilvinod555@indiatimes.com

Abstract

In response to the rapidly changing face of technology and demand for physically smallerwith greater efficiency in every requirement the only solution is Nanotechnology. This papergives introduction to nanotechnology its use in various industries.An analysis of key trends inseveral major industries points to a growing market for several specific types of "nanoproducts." This analysis suggests that in some areas it is unlikely that anything less than ananotech based solution will do. In the case of today's mobile communications and byextension, future pervasive computing environments radical new nano material technologiesare necessary to support the next evolution in computing. The paper also goes on to discusshow and why nanotechnology is uniquely positioned to provide soltions to real worldproblems. There is even the prospect of self–building objects. In other words, the nano-products could be programmed to manipulate the molecules and atoms after they have beenmade.

1. Introduction To Nano-technology

It would help if you have seen movie“Inner Space”, imagine a small doctortraveling inside your body fixing upwhatever is wrong or envisage yourselfstuck in a traffic jam & being guided by thecomputers in your shirt’s threads to a clearroad or alternatively think of chameleonlike soldiers being in perfectly with theirsurroundings & sensing all oncomingattacks All these are not mereimaginations, they would be realities in thebrave new world of Nanotechnology, atechnology that would be used in this & somany more things we have not evendreamed of. All this is going to happensooner than we expect.The prefix ‘Nano’expresses extreme smallness.Nanotechnology refers to nanometer-scalescience and technology. One nanometer(nm) is one billionth of a meter, i.e. around80,000 times smaller than the width of ahuman hair.Nanotechnology is the studyand manipulation of tiny objects at thedimension of molecules and atoms. Itinvolves the control of materials at theNanoscale, achieving miniaturizationthrough atomic and molecularmanufacturing techniques. The potential

benefits of Nanotechnology are bothpervasive and revolutionary.Nanotechnology, which deals with matterat atomic levels, is not just restricted to thefield of medicine. Nanotechnology puts thepower of creation into human hands butcontrary to popular perception, theimmediate goals of Nanotechnology are notto further life & conquer death. It is moreof a quest for discovering Nanostructuresthat may have excellent electrical,chemical, mechanical, or optical properties.Nanotechnology is truly multidisciplinary.Materials scientists, mechanical andelectronic engineers, and medicalresearchers are teaming up with biologists,physicists and chemists. Research at thescale-scale frontier is unified by the need toshare knowledge, tools and techniques, andexpertise on atomic and molecularinteractions. Powerful new concepts andcapabilities, such as atomic-scale imagingand manipulation, self-assembly,knowledge of biological structure-functionrelationships, together with increasinglypowerful computing tools, are rapidlyconverging from different research fields.These will enable Nanotechnology to

progress and researchers to expand theirexpertise into new application fields.

2. History of Nano-technology.

The term ‘Nanotechnology’ waspopularized by K.Eric Drexler in 1986when he came out with a book called“Engines of Creation”, in which hedescribed what is possible with scaletechnology.However, one of the first practicalnanotechnological advances could be tracedback to 1968, when Bell Labs developedmolecular epitaxy, a technique to depositsingle atomic layer on a surface. One ofthe practical to effectively useNanotechnology happened in 1981, whenGerd Bining deployed the scanningtunneling microscope to image individualatoms. This was followed by the creation ofbuckyballs in 1985. Buckyballs measureabout a nano meter in diameter & are usedwidely for Nanotechnology applications. Samiol Lijima of NEC discoveredcarbon Nano tubes, yet another majornanotechnological advancement, in 1991 &in 1998 the 1st transistor was made from ananotube by Cess Dekker.The fact thatsingle molecules can act as molecularswitches was demonstrated in 1998according to research held at RiceUniversity. The start of 2000 saw a greatboost to Nanotechnology in the form of theNational Nanotechnology Institute (NNI) inthe U.S. NNI aims to provide more funding& greater public participation in the field ofNanotechnology.

3. Application of Nano-technology.

Establishment of pinpoint dopingtechnology to a Nano-scale semiconductorregion by single ion implantation. In asemiconductor device smaller than 0.1micron, a statistical fluctuation due toPoisson distribution of dopant atom numberbecome a major problem, since it cannot beeliminated by simply improving theconventional doping techniques such as ionimplantation and diffusion. A deviationof electrical properties due to thefluctuation prevents further reduction ofchannel length, higher packaging density,higher device performance and so on. Inorder to reduce the fluctuation in electricalcharacteristics, we have successfullydeveloped single ion implantation (SII),

which enables us to implant dopant atomsone-by-one into a fine semiconductorregion until the necessary number isreached. So far, the aiming precision in theSII was only 200-300 nm due to a choppingfor extracting single ion from a stream ofions.A focused ion beam (FIB) optics forthe SII has been modified in order toimplant single ion into Nano-scalesemiconductor region. By extending a distance between thechopping electrode and objective lens (OL)electrode and reducing a working distance,the scale of OL (1/6) was designed to be1/19.In addition, we newly added electrodesbetween the chopping electrode and OLelectrode for the precise beam alignment. The beam diameter reaches less than20 nm, as shown in Fig. 1.

Figure-1

The deviation of single ionincident site was reduced to less than 100nm by 200-300 nm before remodeling. This modification of FIB opticsenables us to implant dopant ions into aNano-scale semiconductor region withpinpoint accuracy. An investigation ofthe correlation between the position ofdoping atoms in fine semiconductor regionsand electrical properties is in progress now. Control of an electrical characteristicof sub-micron semiconductor devices bysingle ion implantation. The inherentfluctuation of electrical properties in a finesemiconductor region has been successfullyreduced for the first time by implanting asmall number of doping atoms by means of

single ion implantation (SII). Trimmingof the conductance of a fine resistor whichcorresponds to an active region insemiconductor devices has been tried byusing the SII. Firstly the conductanceincrease per one dopant atom in a sub-micron scale Si resistor was measured to be18 nS/atom.

Secondly very fine test resistors with a sizeof sub-micron were made by conventionaldevice fabrication technology and thestatistical distribution of conductance in thetest devices was obtained. Then thenumber of single ions necessary to trim theconductance value to a certain value in thehigher side of the initial distribution wasimplanted to each test resistor. The initialconductance fluctuation of 6% has beenreduced to only 13%. Through this study,it turned out that the control of not only thenumber of impurity atoms but also itsposition was essential. Future applicationsof mass separated broad ion beams in thefield of Nano-technology The conventionalion implantation in the keV- or MeV-energy range is an ion technique for thinlayer technology in the 0.1 - 5 µm thicknessrange. Our mass separated broad ion

beam sources can be used down to verylow ion energies (from 20 eV to 1000 eV),which opens new fields of applications inthe monolayer- and nanometer-layerthickness range like: Low energy ion beams without anysputtering can be generated for surfacemodification.Mass separated soft ion implantation in thenm-range. Defined mass selected organicor inorganic ions, radicals or functionalgroups can be used for monolayer surfacemodification.

4. Future Nano Applications.

4.1. Mass selected Etching/Depositon

i. Mass separated reactive ion beametching with minimal ion damage atsemiconductors by controlled, depthdependent mass selection.

ii. Direct ion beam polymerization atlow ion energies of nm-polymerlayers by controlled, thicknessdependent mass selection.

4.2. Nano-ion implantation.

i. Doping of organic semiconductorsby low energy ion implantation withselected functional groups forpolymer LED´s for displays ororganic photovoltaic elements.

ii. Low energy ion implantation ofshallow junctions in sub micrometerstructure technology (0.2 - 10 keVfor 0.07µm-technology in silicon).

iii. Stoechiometric ion implantation fornano-tribology (surface hardening ofmicro machine tools).

iv. Low energy hydrogen ionimplantation for semiconductorpassivation (AIIIBV, SiC...)

4.3. Monolayer surfacemodification.

i. Monolayer surface modification ofinorganic substrates (like silicon...)with functional groups for dockingof selected macromolecules(biotechnology),polymer surfacemodification by selected functionalgroups like NH, NH2, CO, OH,...

semiconductor and isolater surfacemodification for direct waferbonding in vacuum.

5. Economic Potential.

Nanotechnology has the potential tosignificantly impact on materials sciencesand on manufacturing processes, on Nano-electronics and computer technology, onmedicine and health by allowing for newdiagnostic systems and monitoring systemsfor bodily functions.Nanotechnology canplay an important role in space exploration,monitoring of the environment and the useof energy resources. It can offer new ways for biotechnologyand agriculture.Nanotechnology has anenormous variety of applications. Severalfields of Nanotechnology can bedistinguished, such as: Nano-materials,Nano-electronics and Nano-biotechnology,which enable researchers to operate at thelevel of molecules an CommercialNanotechnology products are alreadyavailable and include for instance newsemi-conductor lasers and computer harddisk drives based on giant magneto-resistance. Novel materials are being marketed,such as for spectacles with scratch-resistantNano-coatings or sunburn lotionscontaining ultraviolet-absorbing Nano-particles. The bio-chip arrays currentlybeing produced are revolutionizing thedesign and output of gene analysis in thefields of biotechnology and biomedicine.

6. Ethics in Nano-technology.

Nanotechnology deals with the mostbasic assembly of matter.This is likedelivering the power of creation intohuman hands.Consider the concept of selfreplicating robots that traverse the humanbody providing all sorts of cures. The onlyself replicating mechanism we know of arethe reproductive mechanism of living cells. Chances of a deliberate misuse of thistechnology are even higher .One only hasto think of the immense destructivepotential that biotechnology has broughtabout through weapons of biologicalwarfare. Some experts have called forbanning Nanotechnology but this will belike killing one of the greatest developmentin technology even before its happened. This is where ethics takes the centerstage

7. Nano revolution.

There is a revolution. So far mostpeople don't know very much about it. It'smostly a few scientists, engineers andtechnologists like the ones at the PacificNorthwest National Laboratory who areexcited. We are in awe about thepossibilities of creating things that don'tpresently exist.There are almost an infinite number ofways to assemble atoms and molecules, thebasic building blocks of matter. Not longago we thought about these things but nowthe capability to control the movement ofatoms exists. All of this happens in theworld of the very small with dimensions ofone billionth of a meter, a nanometer. The Nanorevolution is happening.There is no doubt that it will take its placein history along side of the discovery anduse of fire, the introduction of agricultureand the industrial revolution. Theserevolutions happened over considerablelengths of time, even centuries.In some parts of the world they are still inprogress. In contrast, the Nanorevolutioncan be expected to blossom in the next fewdecades. Things are already happening veryfast. We can expect to see dramatic changesright before our eyes. "Imagine a technology so powerfulthat it will allow such achievement asdesktop manufacturing, cellular repair,artificial intelligence, inexpensive spacetravel, clean and abundant energy, andenvironmental restoration; a technology soportable that everyone can reap its benefits;a technology so fundamental that it willradically change our economic and politicalsystems; a technology so imminent thatmost of us will see its impact within ourlifetimes. Such is the promise ofNanotechnology."

8. Nanotechnology Research.

Nanotechnology research at NMRCencompasses the design, synthesis,fabrication and characterization ofNanostructures and Nanosystems. Theresearch approach is to performfundamental scientific research and toestablish core research and technologyplatforms in order to: Develop a newunderstanding of Nanoscale phenomenaand construct new Nanoscale structures,devices and systems.

Use these new Nanoscale systems as atool-kit to develop new applications inscience and engineering. NMRC aims toprovide a complete Nanotechnologydevelopment loop to enable innovativeexploitation of Nanosystems specificallywithin emerging Information andCommunication Technology (ICT)application areas, e.g., Nanoscaleelectronics and at the interface betweenICT and other disciplines, e.g., withphotonics (Nano photonics) and with lifesciences (Nanobiotechnology). Highlightsof the Nanotechnology research activities atNMRC during 2000 are outlined below: -

8.1. Molecular Electronics.

Self-assembly of Nanocrystals asNanoscale electronic devices offerspossible alternatives toknown.Nanofabricationchallengese.g.,Nanolithography, while opening the way to newgenerations of electronic devices thatoperate on fundamentally different physicalprinciples. Nanoparticle-based electronicdevices may be assembled usingbiologically- inspired assembly approaches. We have successfully employed DNAas a tool for assembly of metallicNanoparticles. Short oligonucleotidesattached to nanoparticle surfaces are usedto link the nanoparticles together by self-assembly of complimentary oligonucleotidestrands. This "Nanoparticle zipping"process can be monitored optically as afunction of solution temperature (belowleft). Also, within the Nanostructurecharacterization facility, we are currentlystudying the electrical transport propertiesof prototype Nanodevices based on self-assembled arrays of metallic Nanoparticle s(see below right).

Figure -3Figure shows temperature dependentzipping and unzipping of oligonucleotide

strand linked gold Nanoparticle smonitored as a function of inter-particledistance.8.2. Design and Simulation Tools forMolecular Electronics

Figure

-4

figure above shows Simulating prototypemolecular electronic devices: Results onthe calculation of the binding configurationof a methanethiol group to the (111) face ofan Au13 cluster). Development of amolecular electronic transport description isbeing pursued as part of a generalnanoelectronics technology computer aideddesign (NANOTCAD) tool. Formulationsof electronic transport are being devised fora full quantum mechanical description ofdevices at the atomic and single electronscales.For example, to understand aspects of theinteraction between a molecule attached toa metal surface in a molecular electronicdevice, calculations have been performedon the binding of, e.g., methanethiol ontothe faces of a Au13 clusterSuch work is beginning to yield basicinsights into the structure and energy levelarrangements of molecular electronicdevices.

10. Advantages of Nano-technology.

Imagine consumer goods that replacethemselves in the future. It seems like somuch science fiction, but some scientistssuggest that this technology is very nearreality. Other things that could be achievedwith this technology include the creation ofcomputer chips that would be much fasterdue to the smaller components that can bemade. Of course it is in the medical fieldthat Nanotechnology can really produce

miracles. Imagine a nano-robot that isprogrammed to travel through yourbloodstream and is capable of cleaning outany fatty deposits, so reducing thelikelihood of heart diseases. There are anumber of amazing possibilities in thiscontext. It has also been suggested thatusing Nanotechnology, medical diagnosiswill be transformed and that the use ofnano-robots within the body could providea defense against invading viruses. This hasparticular application when considering theimmune system as this technology could beused to combat immune deficiency diseaseslike HIV/AIDS. Another possibly is the development orcreation of food. As food is also acombination of atoms, there is notheoretical reason that once perfected, thistechnology could not actually be used toproduce rather than grow food. Thepossibilities are endless. There is evenspeculation that the earth could beecologically reshaped or "terraformed".This could also mean the reintroduction ofalready extinguished species of animals. Ofcourse this all lies in the future. However,one only has to think of other technologies,including the home computer, which, onlya few years ago, were the stuff ofimaginative science fiction.11. Flaws of Nano-technology.There is always a downside.One of the aspects of this new technologythat has to be carefully considered is, whowould control a technology as powerful asthis promises to be?This is always a possibility that those whodo control this technology would not use itto the advantage of everyone. Lastly,change in itself can bring about problems. Change that is too rapid could upseteconomies and create disruption instead ofconstruction.12. Conclusion.

Nanotechnology itself may never become ahuge industry in the classical sense but itcould very well have an impact on thecommercial world. Nanotechnologypromises a new, fast world to the futuregeneration. We can hope for the earth to beecologically reshaped giving rise to thealready extinguished species.

13. References

[1] Eric K. Drexler “Engines of Creation:The Coming Era of Nanotechnology”

[2] Carol Crane, Michael Wilson, KamaliKannangara “Nanotechnology”

[3] Bhushan,Bharat “Handbook onNanotechnology”