Robert W. Cohn ElectroOptics Research Institute ...eri.louisville.edu/papers_pres/ECStalk4web.pdfFOR...

Robert W. CohnElectroOptics Research Institute

& Nanotechnology CenterUniversity of Louisville

* With apologies to similarly titled books by R.P. Feynman and R. Fulghum

Good and bad definitions of nanotechnology

Is there still plenty of room at the bottom? Current limits to seeing and manipulating atoms

Some practical limits to nanodevice fabrication

Examples of nanotechniques that make research easier rather than harder

Conclusion: The lasting effects of nanotechnology

�The emerging fields of nanoscale science, engineering, and technology - the ability to work at the molecular level, atom by atom, to create large structures with fundamentally new properties and functions - are leading to unprecedented understanding and control over the basic building blocks and properties of all natural and man-made things.� M.C. Roco, NSF

�Much of nanoscience is, however, done in university laboratories, and a scanning probe microscope that is local probably has more impact on the rate of progress of the field than an electron microscope located in a different state.�

G.M. Whitesides, Harvard U.

�I find that the very term �nanotechnology� � although wonderfully suited to the description of a welcome and significant funding initiative � is at too high a level of abstraction for our purposes here today. Which �nanotechnology� are we supposed to be talking about?� J.A. Armstrong, IBM

�Nanotechnology is what I do.� S.M. Block, Stanford U.

�... a lot of resources go into the re-presentation and re-labeling of ongoing work, which nevertheless remains very much the same ...� H. Glimell, Göteborg U.

�Nanotechnology Spans the Conventional Disciplines. .... Scientists and engineers developing nanoscience and technology will have to be aware of a broader and different range of subjects than those included in the usual departmental curricula.� G.M. Whitesides, Harvard U.

�Unfortunately our engineering education system is not geared, for the most part, to teaching a unified approach to understanding and using science. ... Developing a broadly trained and educated workforcepresents a severe challenge to our four-year degree and two-year degree educational systems, which favor compartmentalized learning.�

S.J. Fonash, Penn State U.

�There is a long heritage within academia of the single discipline as the core entity of organization. Even in areas where external forces have exerted strong pressure to transcend them, disciplines have proven amazingly persistent.� H. Glimell, Göteborg U.

Use nanotechnology as a tonic that develops interdisciplinarity

SIZE COMPARISON OF BIOMATERIALS,ELECTRONICS & THE THREE BEAMS

S. Asai and Y. Wada,Proc. IEEE, April 1997

IMAGING ATOMIC STRUCTURE

Transmission ElectronMicrograph

by E. C. DickeyUniversity of Kentucky

ELECTRON STANDING WAVE ELECTRON MIRAGE

Don Eigler Group, IBM (see Nature 2/3/00)

Chemistry, molecular biology and mechanics merge at the nanoscale

4 nm

THE KINESIN MOTOR PROTEIN

Vale & Milligan Science (4/7/00)

Measures force applied by

kinesin

Has been used to unwrap folded

molecules

Motor proteins have been attached to

silicon propellers

Steven Block,Stanford

E-beam written guitar strings are 50 nanometer diameterCornell National Nanofabrication Users Facility, Laser Focus 9/97

WRITING SPEED versus RESOLUTIONFOR VARIOUS PATTERNING METHODS

S. Matsui, Proc.IEEE, April 1997

The tip is 6 �m long with a 20 nm tip radius

1 �m100 nm

Hong &Mirkin,

Northwestern

Silicon dioxide line on silicon written & profiled by AFMElectron beams also will directly oxidize silicon

Produced by chemical etching of AFM written lines

54 nmX

690 nm340 nm

in x and z

340 nmin x and z

200 nm

200 nm 30 nm

200 nm

200 nm 30 nm

15 nm

15 nm

15 nm

15 nm

AFM oxidized lines on nitrogen-passivated siliconare wet etched to produce vertical, sub-15 nm trenches

Gil Lee, Purdue & NRL

Forcedetection

of DNA

THE MICROFABRICATED BIOCAPSULENANOPORE MEMBRANE

ENCAPSULATEDCELLS

INSULIN

IMMUNOGLOBULINSNUTRIENTS

Mauro Ferrari,Ohio State

SILICONTO

SILICONBONDING

P+ poly-Si

P+ Si

Silicon

Thin oxide

After oxide etch the sidewall coating givesnanometer thick, microns in length pores

M. Ferrari,Ohio State

Nano-methods are quickly being adopted by academic institutions worldwide because of their ease of use and low cost

The interdisciplinarity of nanoscience requires and motivates improved learning, retention and creative application of the fundamentals of science

�Wisdom is not at the top of the graduate school mountain,but there in the sandpile �� R. Fulgham

�Be aware of wonder.� R. Fulgham

�� it might be just for fun.� R.P. Feynman

Surely you're joking, Mr. Feynman that "All I really needed to know (about nanotech)

I learned in kindergarten"

�Warm cookies and milk are good for you.� R. Fulgham

(not shown at talk)

From "All I Really Need to Know I Learned in Kindergarten�Robert Fulghum

All I really need to know about how to live and what to do and how to be I learned in Kindergarten. Wisdom is not at the top of the graduate school mountain, but there in thesandpile...Share everything.Play fair. Don't hit people.Put things back where you found them. Clean up your own mess.Don't take things that aren't yours.Say you're sorry when you hurt somebody.Wash your hands before you eat. Flush.Warm cookies and cold milk are good for you.Live a balanced life - learn some and think some and draw and paint and sing and dance and play and work every day some.Take a nap every afternoon.When you go out into the world, watch out for traffic, hold hands, and stick together.Be aware of wonder.And remember the Dick-and-Jane books and the first word you learned - the biggest word of all - LOOK.

SiO2 line on (110) siliconwritten & profiled by AFM

Vertical nanostructures byTMAH etch of SiO2 lines

Concept for WDM multibandfilter by AFM lithography

THE 3D NANOSCALE IMAGING FACILITYECS-9724371: MRI grant to R. W. Cohn et al., U. Louisville

10 �m

25 �m

25nm

1 1 -1 0 1 1

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85 nm

1 nm

Goal: Locate complementary microscopes in one facility for materials & devices faculty: AFM & Wyko optical profiler from NSF + SEM from UofL.Results: Started new research studies in nanofabrication (see figs below)Delivered new course Nanotechnology: Survey & Lab Practice (Sp�2000)

340 nm(in x and z)

54x

690nm

200 nm

30 nm

15 nm340 nm

(in x and z)2D grating

by AFM

AFMtrenches

on nitridedsilicon

aperiodicproposed

periodic

aperiodicgeneral

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magnitudes: 1 1 .1 .2 1 .1 .3 1 1phases: �0o

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GENERALIZED GRATING FILTERSMADE POSSIBLE BY NANOLITHOGRAPHY

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e re

flect

ivty

1�s

0�s

-1�s

Desired & approximated impulse response

Fourier spectra from desired & approximated functions

Wavelength (nm)W

avel

engt

h re

flect

ivity

(db)

633 640 647

0

-10

-20

-30

-40

GRATING FILTER DESIGNUSING REFLECTIVITIES 1, 0, -1

3 nm thick SiO lines on silicon written by AFMfollowed by anisotropic vertical etching

10 �m

25 �m

25 n

m

1 1 -1 0 1 1

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VERTICAL ETCH PLANES ON [110] SILICON

With KOH {110} plane etches 120X faster than the {111} planeResist lines in the {111} directions define vertical ridges

{100}{111} {111}