carbon nanotubes and electronics - ieeeewh.ieee.org/soc/cpmt/presentations/cpmt0511.pdf · scv...

SCV Chapter, CPMT Society, IEEE November 9, 2005

1

Carbon nanotubes and electronics

Dana Hammer-FritzingerAlan RaeNovember 2005 CPMT Society SCV Chapter meeting

Contents

Nano and electronicsCarbon nanotubesElectronics opportunities and challenges

http://www.cpmt.org/scv/


2

Why is NanoDynamics involved in electronics?

Delaware C-corp started in 2002 and led by executives with an average of over 25 years experience in advanced technologyincluding electronics (materials, equipment and devices)

Headquarters, laboratory, and manufacturing facility in Buffalo, NY

Research operations in Columbus, OH and Pittsburgh PA

Over 70 employees, more than 15 PhDs and strong contract research links to universities and other companies

Focused on commercialcommercial applications of nanomaterials, nano-intermediates, and nano-enabled products

1/3 of applications will be in electronics (NNI)

NanoDynamics is active in SEMI, iNEMI, IPC and SMTA

Strategic Business Units


3

NanoDynamics and Carbon Nanotubes

Carbon Nanotubes

Novel process yields:Breakthrough economiesNew product possibilitiesApplications flexibility

CNT on a carbon fiber


4

Status & Outlook

Multi-wall carbon nanotubes produced by a low-pressure process singly or on substrates

Intellectual property in place

Pilot facilities in place and operational

Product being sampled & qualifiedin select applications

Working with NanoCyl (one of Europe’s largest producers) to introduce their powders in the USA

The ABC’s of NanotechnologyA – Awfully small; a nanometer is:

. 00004 mils for the mechanical engineers

.001 microns for the electrical engineers0.5 times the diameter of a strand of DNA for the biologists

B – Big businessWorldwide, investment in nanotech research exceeds $9 billion, $1 billion by governments this year in the USA, Europe and Japan EACH.Over 1600 nanotech companies have started up in the past 5 years70% of the companies making up the DJIA have declared a nanotech strategy

C – Cause for concern and considerationA disruptive technology that will impact businesses large and small, along with major economic and military considerations in the next ten years


5

Impact on Industry

Impact on Electronics Manufacturing

Nanotechnology and Nanomaterials are toolsThey are here, they will be improved, and they will continue to offer economic and performance options that have not been available with conventional materials

First applications will be in filled, composite and sinterable systems


6

Current applicationsStructural

Sporting goods – tennis, hockey, golf, bikes, F1

http://www.eastonbike.com/ http://www.zyvex.com/Significant improvement in strength by reinforcing epoxy in epoxy-carbon fiber composites at ~1%

…and several military applications we won’t discuss..

Why are nanotubes interesting?

They are carbon cylinders with strong pi bonding similar to the planes in graphite

High physical strength along the cylinderHigh electrical conductivity along the cylinder

Depending whether the atoms show straight or a spiral arrangement they can be conducting or semiconducting

High thermal conductivity along the cylinder>1000 Wm0K, more than twice that of copper


7

Types

Single wallSemiconducting or conducting

Double wallMultiwallFunctionalized

Coupling agents to improve adhesion to polymers


8

How are they made?Vapor phase processesCatalytic decomposition of hydrocarbons e.g. ethylene on a transition metal catalyst

Catalyst can be on a surface, on a substrate e.g. ceramic…


9

CNT examples

Multiwall on a carbon fiberMultiwall bulk


10

Making them

High pressure or combustion processes(they do occur naturally in low yields - you make them yourselves in your barbecue or diesel engine!)

Collect by growing selectively from a substrate and harvestingEasier to make multiwall than single wallDifficult to

get them straight.separate conducting from semiconductingseparate from amorphous carbon, catalyst residues etc.


11

Structure of the nanotubes after synthesis

Aggregates are large: must be disentangled during the dispersion process Strong influence of the texture of the aggregates on the dispersion process

Using them

Difficult toGet pure semiconductors or conductorsPlace individually

An AFM is NOT a practical production tool!Disperse and deposit in bulk


12

Dispersion and distribution of carbon nanotubes:Difficult…

but do-able…

using high-shear melt-blending techniques (e.g. twin-screw extruder, Buss Kneader) with/or modification of the CNT

Using them

Primary applications (within 5 years) will simply use bulk properties

Mechanical strengthElectrical conductivityThermal conductivity

Secondary applicationsSemiconductor structures

Memory, solar cell, sensor, LEDFlame retardants


13

Bulk Properties Electrical conductivity

Percolation limits <3 wt %Opportunities in enhancing existing adhesives, shielding, transparent adhesivesSame concept as structural – add small quantities, not necessarily replace existing systems

Thermal conductivitywmK-1; solder 30 copper 400, CNT > 1000Heat spreaders and TIM

Conductivity is along fibers


14

MFI (@10 Kg) vs Surface Resistivity for PS compound

0

510

1520

25

3035

40

0 2 4 6 8 10 12 14 16Log Surface Resistivity (Ohm/sq)

Nanocyl MWNT CB

MFI

@20

0°C

(g/1

0min

)

Conductive additive-Resistivity


15

Semiconductor properties

High electron mobilityMuch better than organic semiconductors, another challenger to CMOS!

If reliable semiconductor structures can be produced by parallel self-assembly at low cost, CNTs pose a real alternative to CMOS, otherwise they will be a niche play

TransistorsIndividual nanotubes

IBM field effect transistorhttp://domino.research.ibm.com/comm/pr.nsf/pages/news.20020520_nanotubes.html

Planar flexible networks – non aligned

http://www.nano.com/news/archives/publications/Flexible%20Nanotube%20Electronics.pdf

Aligned nanotube networksTI “crossbar latch”

http://www.azonano.com/details.asp?ArticleID=1206

Source Drain

GateDielectric

CNT


16

Memory

Simple principles, difficult execution..Nantero DRAM

Electrostatic switching of CNT filamentswww.nantero.comClose to commercialization

Michigan StateNanotube containing a C60 buckyballhttp://www.pa.msu.edu/cmp/csc/memory.html

SamsungNanotube transistor with a Si3N4 overlay (similar concept to flash memoryhttp://www.trnmag.com/Stories/2003/061803/Nanotube_transistors_make_memory_Brief_061803.html

CNT


17

Other devicesPhotovoltaics / solar cells

http://www.azonano.com/news.asp?newsID=548LED

http://domino.research.ibm.com/comm/pr.nsf/pages/news.20020520_nanotubes.html

SensorsSelective multi-gas sensorshttp://www.clemson.edu/research/ottSite/techs/nopatent/ChopraRao.htm

Field effect displayshttp://news.com.com/Carbon+TVs+to+edge+out+liquid+crystal,+plasma/2100-1041_3-5512225.html


18

In Conclusion

Carbon nanotubes will have a major influence on electronicsThe first will using bulk properties in conductive adhesives, heat spreaders etcThe really big payoff will be in disruptive applications

Semiconductive and novel structuresFirst to commercialize will be displays and memory

[email protected]

carbon nanotubes and electronics - ieeeewh.ieee.org/soc/cpmt/presentations/cpmt0511.pdf · scv...

Documents