Vanzee 1201

22
MOLECULAR ELECTRONICS MOLECULAR ELECTRONICS A Presentation to the Visiting Committee on Advanced Technology On a New Competence-Building Project in 1970 1980 1990 2000 2010 2020 10 3 10 4 10 5 10 6 10 7 10 8 Year 0.01 0.1 1 10 Pentium 4 80486 80286 4004 Number of Transistors Per Chip Feature Size (µm) “Moore’s Law” 11 December 2001

Transcript of Vanzee 1201

Page 1: Vanzee 1201

MOLECULAR ELECTRONICSMOLECULAR ELECTRONICS

A Presentation to the Visiting Committee on Advanced Technology

On a New Competence-Building Project in

1970 1980 1990 2000 2010 2020103

104

105

106

107

108

Year

0.01

0.1

1

10Pentium 4

80486

80286

4004

Num

ber o

f Tra

nsis

tors

Per

Chi

p

Feature Size (µm)

“Moore’s Law”

11 December 2001

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Molecular Electronics?Molecular Electronics?

•What is “Molecular Electronics?”•Why now?

•Who are the players?•How can NIST help?

•Our team approach.•The first year’s progress.

•The road ahead.

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Molecular ElectronicsMolecular Electronics—— moletronicsmoletronics ——

A new technology that uses molecules to perform the function of electronic components.

amplifier

wire

D

A

diod

esw

itchH2N

NO2

SH

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Moletronics in the NewsMoletronics in the News

C&E News

Washington Post

Nature

Physics Today

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Moletronic Moletronic ComponentsComponentsTransistors

Lucent Electrically-ActiveMolecules

Rice, Univ. of Alabama, UCLA

“I was one of the biggest skeptics. Now I believe that this is the inevitable wave of the future.” —R. S. Williams, Hewlett-Packard

NC

N

C

N

C16H33

C

N

junction diode

MemoryMEC, Harvard

RTD

S

S

OO

S SS S

O

OO O O O

O O

N

N

N

N

+

+

+

+

Vc

V1

V2Vout

Logic FunctionHewlett-Packard, UCLA, Mitre Corp. Nanotube FET

IBMswitch

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0.013 µm

16441945

1948

1959

2016

1970 1980 1990 2000 2010 2020103

104

105

106

107

108

Year

0.01

0.1

1

10Pentium 4

80486

80286

4004

Feature Size (µm)Tr

ansi

stor

s pe

r Chi

p

Device Physics Changes

Approaching Fundamental LimitsApproaching Fundamental Limits

ENIAC

Transistor

IC

Moore’s LawComputational Paradigm Shifts

A new components technology is required to maintain the uninterrupted succession of smaller and faster electronic devices.

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• Even big molecules are small.• Functional control through synthesis.• Self-assembling devices.

Why Use Molecules?Why Use Molecules?

metal

HS - R - X

MolecularLengths

1n

10n

100n

10µ

1970 1980 1990 2000 2010 2020

Year

Line

wid

th (m

)

Classical

Quantum

NDR RS

NO2

NH2

H2N

NO2

S

NDR – Negative Differential ResistanceR – Resistor

10 nm

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How Molecules ConductHow Molecules ConductConventional Electronics

insulator

conductor

doped semiconductors

Molecular Electronics

insulator–S—CH2—CH2—CH2 — S –

conductor

–S—CH —C —CH — S –

–S—CAc —C —CDn — S –

substituted molecules

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Moletronic Moletronic ComponentsComponents

NC

N

C

N

C16H33

C

N

Vc

V1

V2Vout

Logic FunctionHewlett-Packard, UCLA, Mitre Corp.

TransistorsLucent

junction diode

OO

S SS S

O

OO O O O

O O

N

N

N

N

+

+

+

+

switch

MemoryMEC, Harvard

Nanotube FETIBM

RTD

S

SElectrically-ActiveMolecules

Rice, Univ. of Alabama, UCLA

“I was one of the biggest skeptics. Now I believe that this is the inevitable wave of the future.” — R. S. Williams, Hewlett-Packard

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A Role for NISTA Role for NIST

To develop the measurement tools and data necessary to measure, model, and control the flow of charge through molecules and ensembles of molecules.

“To knowledge by measurement.” — Kammerlingh Onnes, Leiden Univ.

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Grand ChallengesGrand Challenges

•Develop Moletronics Metrology

• Correlate Structure and Function

Science, vol. 286, p. 1551Sci. Am. June 2000

“The field suffers from an excess of imagination and a deficiency of accomplishment.” —J. Hopfield, Princeton University

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Our Role/The ChallengeOur Role/The Challenge—— What does it mean? How do to make it useful? ——

•What is the physical basis for electrical activity in moletronic systems?

•How are electrical quantities reliably measured at molecular dimensions?

•What measurements and data are needed to speed this technology to market?

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Our GoalsOur Goals• To advance the measurement sciences and

standards as applied to moletronics.– Quantitative measurement and understanding

of molecular conductance– Validated models– Characterized prototype– Test vehicle for molecular components

• To create a nucleation center for speeding the development of moletronics technology.

“New directions in science are launched by new tools much more often than by new concepts.” — Dudley Herschbach, Harvard Univ.

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A Multidisciplinary EffortA Multidisciplinary EffortChemistryChemistry

••SelfSelf--AssemblyAssembly••StructureStructure••MechanismsMechanisms••ModelingModeling

Electrical EngineeringElectrical Engineering••ContactsContacts••IntegrationIntegration••PerformancePerformance••ReliabilityReliability

M. TarlovR. van ZeeM. Tarlov

R. van ZeeJ. SuehleC. RichterJ. SuehleC. Richter

S. RobeyR. van ZeeS. Robey

R. van Zee

C. RichterC. RichterC. GonzalezC. Gonzalez

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Research EmphasesResearch EmphasesElectrical Properties of

Small Ensembles

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

Structure of Electrically-Active, Molecular Films

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

Theory

g(E) = ∆D ∆ Aπhγ2

2e2T2

NH2

NO2

S

Electrical Properties ofLarge Ensembles

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

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1000 1500 2000

In KBr Pellet

Grown from Vapor

Grown in Solution

wavenumber (cm-1)

CH2

CH2

SH

Sangle

- Studying Film Structure --

0 30 60 90

A.M. Bratkovsky, HPRLPhys. Rev. B, 64, 195413

AngleC

ondu

ctio

n

Resistance of Small EnsemblesResistance of Small Ensembles

18 MΩ±12 MΩ

CH2

CH2

SH

SHR.P. Andres et al., Purdue

Science, 272, p.1323

Resistance

p-benzenedimethanethiol

CH2

CH2

SH

S

CH2

CH2

SH

S

CH2

CH2

SH

S

CH2

CH2

SH

S

CH2

CH2

SH

S

CH2

CH2

SH

S

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From Molecules to DevicesFrom Molecules to Devices

Ultra-thin SiO22 nm - 10 nm

No. of Molecules(10 nm - 100 nm)

Molecular Length(2 nm – 10 nm)

Field SiO2

Bottom Electrode

Top Electrode

Low Temp. Au

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

NH2

NO2

S

Top Electrode

Bottom Electrode

- Building Test Structures --

~20 µm

SiO2/Si3N4

~40 nm

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-2 -1 0 1 2 3 40

10

20

30

40

Curr

ent (

pA)

Applied Voltage (V)

Testing Device PerformanceTesting Device Performance

D.R. Stewart et al., HPRLBull. Am. Phys. Soc., 46, p.1

CH3(CH2)18CO2H

Al

Al

Ti

Al2O3

OHO

OHO

OHO

OHO

OHO

OHO

OHO

OHO

OHO

OHO

OHO

OHO

OHO

OHO

OHO

OHO

0.72

0.73

0.74

0.75

Capa

cita

nce

(pF)

“1”High

current“0”

Low current

CrossBars

Probe Station

- Reliable Electrical Measurements --Device OperatingCharacteristics

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Kohn-Sham Equations

F[p(r)] = Ehf [p(r)] + Ex [p(r)]

T+Vhf(r)+Vn(r) + Vx(r) ϕi = ε ϕ i

0.0 0.5 1.0 1.5 2.0 2.5-0.1

0.0

0.1

0.2

Curr

ent

Charge on Rings (AU)

Applied Voltage (V)

Upper Ring - RU Middle Ring - RM Lower Ring - RL

Charge on Rings

Modeling Molecular SwitchesModeling Molecular Switches

• Significant charge density localization at voltages below 2.1 V (no current).

• Near 2.1 V maximum de-localization of charge density (maximum current).

• Above 2.1 V charge density localization occurs again (no current).

–S—RL—RM—RU <2.1 V

–S—RL —RM —RU ~2.1 V

NH2

S

NO2

RU

RM

RL

- Understanding Electrical Function and Molecular Structure --

–S—RL—RM—RU >2.1 V

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The Road AheadThe Road Ahead

•Small Ensemble Conduction Experiments

•Test Structure Assessment

•Electronic Structure Characterization

•Conduction Modeling

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Leveraging our ResourcesLeveraging our Resources•Nanocell Molecular Computer Collaboratory(Molecules, Electrical Characterization)

–J. M. Tour, Rice University–M.A. Reed, Yale University–P.S. Weiss, Penn State University

•Hewlett-Packard Research Labs(Devices, Electronic Structure)

–R.S. Williams–P.J. Kuekes

•Naval Research Laboratory(Molecules)

–R. Shashidhar

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Molecular Electronics!Molecular Electronics!•Important Technology

•Revolutionary•Timely

•Critical Role for NIST

• Interdisciplinary Team•Strong Partnerships with Industry & Universities

Strategies for Success