Teaching Nanoelectronics

Teaching Nanoelectronics

Paolo Lugli

Institute for NanoelectronicsMunich, Germany

2

Outline

The Institute for Nanoelectronics at TUM

What is Nanoelectronics ?

Evolutionary vs. disruptive approaches More Moore More than Moore Beyond Moore

How do we teach Nanoelectronics ?

Diplom, Bachelor and Master of Science in Electronics and Information Technologies (EI) at TUM

International Master Programs at TUM Joint Master Program at NTU-Singapore New Joint EI-PH Master Program in “Nanoscience and

Nanoengineering” at TUM

Conclusions

Institute for Nanoelectronicswww.nano.ei.tum.de

Experimental activities

Nanoimprinting

Ni stamps

Si masters

100 nm50 nm

30 nm

10 nm

Nanoimprinting with MBE mold (for sub 10 nm resolution), with homemade imprinter

Commercial imprinter (up to 2,5”, down to 50 nm resolution)

• Photonic crystals• Nanopatterning for quantum wire growth• Metallic molds• Patterning of organic films. Sub-wavelength grating

Fabrication of organic devices

400 500 600 700 8000

20

40

60

80

100

85% @ 550nm

EQ

E [

%]

Wavelength [nm]OPD external quantum efficiency

S D

PEDOTgate

Plastic substrate

PVA

Electro-optical nanodevice characterization

Si nanowire FET

IR emission of a Quantum Cascade Laser


Modelling/simulation activities

Multiscale approach for Nanoelectronics: from Devices to Architectures

Device-level models

• Drift-Diffusion simulation for organic devices (TFTs, OLEDs, photodiodes, solar cells)• Ab-initio modeling of single molecule diodes and CNTs• Monte Carlo simulation of quantum devices

Au

Architectures

• Passive Crossbar non Volatile Memories• Capacitive / Ferroelectric Memories• Quantum Cellular Automata logic architectures

SPICE-level models

• DC circuit models for nanodevices• Coupling quantum circuits to resonators• Design of hysteretic devices• Analysis of active matrix array for imagers

Quantum circuit

inV outV

inC outC

C

R

L C

qRqL

M

Nanoelectronics

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• Nanotechnology is the design and construction of useful technological devices whose size is a few billionths of a meter

• Nanoscale devices will be built of small assemblies of atoms linked together by bonds to form macro-molecules and nanostructures

•Nanoelectronics encompasses nanoscale circuits and devices including (but not limited to) ultra-scaled FETs, quantum SETs, RTDs, spin devices, superlattice arrays, quantum coherent devices, molecular electronic devices, and carbon nanotubes.

• Negative resistance devices, switches (RTDs, molecular), spin transistors• Single electron transistor (SET) devices and circuits• Quantum cellular automata (QCA)

Limits of Conventional CMOS technology• Device physics scaling • Interconnects

Nanoelectronic alternatives?

Issues • Predicted performance improves with decreased dimensions, BUT• Smaller dimensions-increased sensitivity to fluctuations• Manufacturability and reproducibility• Limited demonstration system demonstration

New information processing paradigms

• Quantum computing, quantum info processing (QIP)• Sensing and biological interface• Self assembly and biomimetic behavior

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Motivation for Nanoelectronics

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The roadmap

Semiconductor technology trends (ITRS 2006)

8

Materials for Si-nanoelectronics

At the origin of Si microelectronics only few elements were necessary for the whole processes. Current technology requires a much larger number of materials.

Source: Intel 9

Source: Intel 10

More Moore -> Beyond Moore

11

Robert Chau, Intel, ICSICT, 2005

Critical issues

198810-1

Year

Ch

an

nel Ele

ctr

on

s

1992 1996 2000 2004 2008 2012 2016 2020

100

101

102

103

104

16M64M

256M1G

4G16G Memory Capacity/Chip

4M

12

Nano-Device Structure Evolution

13Source: Intel

Lg = 1.3µm; Ø = 26 nm; tox = 300nm SiO2

•Normally-off

•Schottky contacts -2,0µ

-1,5µ

-1,0µ

-500,0n

0,0

-2 -1 0

-Vgs

-20 V

-15 V

-10 V

+5V; 0 V; -5 V

drain bias Vds

[V]

drai

n cu

rren

t I d

[A

]

20V;

Weber, W.M. et al. IEEE Proc. ESSDERC 2006, p. 423 (2006)

gate

S D

Vd

Vg

Id

NW

Si-NW transistor: output characteristics

15

Possible Quantum Dot Applications

PhotodetectorInputQuantum dots or

single electron transistorsas processing elements

CMOS Drivers providing fan-out

Single “cell” of a Cellular Architecture

Single Electron Memory Nanoelectronic Integrated

Circuit (NIC)

Quantum Cellular Automata Quantum Computation (QBITs)

“1” “0”

1

23

4

0

source drain

nanocrystalsgate

SiO2

gateMemorynodeSi channel

SiO2

Quantumdots

Tunnelingbarriers

Quantumdots

16

17

Beyond Moore

Beyond CMOS logic and memory device candidates:

• Nanowire transistors

• CNT transistors

• Resonant tunneling devices

• NEMS devices

• Single electron transistors

• Molecular devices

• Spintronic devices

All those candidates (some of which not yet demonstrated) still suffer from major reliability and stability problems

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Molecular components

OPV11 molecules with simplified phenyl side chains synthesized by the group of Prof. Dr. E. Thorn-Csányi at the University of Hamburg)

In collaboration with G. Abstreiter, WSI, M. Tornow, TU Braunschweig

20 nm embedded GaAs layer after etching and deposition of 3 nm Ti and 7 nm Au.

5 nm embedded GaAs layer after etching and deposition of 2 nm Ti and 6 nm Au.

S. Strobel et al., SMALL 5, 579-582 (2009)

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Cross bar non volatile memory

V

The current-voltage characteristics of molecules is typically hysteretic, with step-like nonlinearities and possibly non-symmetric (rectifying) behavior.

A crossbar memory – probably the simplest possible functional circuit – is one of the proposed application of single molecule electronics

G. Casaba et al., IEEE Transactions on Nanotechnology, 8, 369 (2009)

Problems with single molecule devices

-3 -2 -1 0 1 2 3-500p

-400p

-300p

-200p

-100p

0

100p

200p

300p

400p

500p 0Down (P03:S05-08-) 1Up (P03:S05-08-) 1Down (P03:S05-08-) 2Up (P03:S05-08-) 2Down (P03:S05-08-) 3Up (P03:S05-08-) 3Down (P03:S05-08-) 4Up (P03:S05-08-) 4Down (P03:S05-08-) 5Up (P03:S05-08-) 5Down (P03:S05-08-) 6Up (P03:S05-08-) 6Down (P03:S05-08-) 7Up (P03:S05-08-) 7Down (P03:S05-08-) 8Up (P03:S05-08-) 8Down (P03:S05-08-) 9Up (P03:S05-08-) 9Down (P03:S05-08-) 10Up (P03:S05-08-) 10Down (P03:S05-08-) 11Up (P03:S05-08-) 11Down (P03:S05-08-) 12Up (P03:S05-08-) 12Down (P03:S05-08-) 13Up (P03:S05-08-) 13Down (P03:S05-08-) 14Up (P03:S05-08-) 14Down (P03:S05-08-) 15Up (P03:S05-08-) 15Down (P03:S05-08-) 16Up (P03:S05-08-) 16Down (P03:S05-08-) 17Up (P03:S05-08-) 17Down (P03:S05-08-) 18Up (P03:S05-08-) 18Down (P03:S05-08-) 19Up (P03:S05-08-) 19Down (P03:S05-08-) 20Up (P03:S05-08-)

Cur

rent

[A]

Voltage [V]

G17-1c, P03, S05, über Nacht

A large variation is found in the IV characteristics between succesive sweeps.

Reasons can be due to:

• Configurational changes in single molecules• Variation in the number of molecules attached to the electrodes• Changes in the bond of a single molecule to the metal contact• …

Such variability has to be dealt at a circuit/architecture level

Molecular transistor

Back gate: a molecule attached to source and drain electrodes on an oxidized metal or heavily doped Si gate (substrate). This is the same configuration of the Thin Film Transistors

Electrochemical gate: a molecule bridged between source and drain electrodes in an electrolyte in which a gate field is applied by a third electrode inserted in the electrolyte.

Chemical gate: current through the molecule is controlled via a reversible chemical event, such as binding, reaction, doping or complexation.

Once a conducting molecule is set between 2 contacts, an additional electrode has be introduced as gate. There are various possibilities:

Coupled nanomagnets

Fabrication and pictures by A. Imre

Investigations of permalloy nanomagnets (thermally evaporated and patterned by electron beam lithography) confirm the simulation results

Sim

ulat

ion

AF

MS

imul

ated

fiel

dM

FM

Courtesy of W. Porod, Notre Dame University

Planar Majority Gate Design

Output points down only if both inputs are pointing up NAND gate.

•Difficult to design – ferro- and antiferromagnetic couplings to the central dot should be equally strong

•Electrical inputs are difficult to fabricate – horizontally lying dots provide a hard-wired input. No output, we just imaged it with the MFM

•Design is based on Parish and Forshaw: Magnetic Cellular Automate Systems IEE Proc.-Circuits Devices Syst., Vol. 151, No. 5, October 2004

Programming input (bias to center dot)

Input A

Input B

Output

Imre et. al. Science 2006

3

200 nm

Working majority gate with nanomagnets

24Imre et. al. Science 2006

SEM images MFM images

Logic with nanomagnets

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In collaboration with M. Becherer and D. Schmit-Lansiedel (TUM) , W. Porod (Notre Dame)

Outputs

Inputs

Information propagation

The challenges:How to make signals propagating? Integrated clockingHow to write in the magnets? Localized field from wiresHow to read out the magnets? Hall sensor

M. Becherer et al., IEEE TRANSACTIONS ON NANOTECHNOLOGY 7, 316 (2008)

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More than Moore

Interfacing to the real worldIf the interaction is based on a non-electrical phenomenon, then specific transducers are required. Sensors, actuators, displays, imagers, fluidic or bio-interfaces (DNA, Protein, Lab-On-Chip, Neuron interfaces, etc.) are in this category

Enhancing electronics with non-pure electrical devicesNew devices can be used in RF or analog circuits and signal processing. Thanks to electrical characteristics or transfer functions that are unachievable by regular MOS circuits, it is possible to reach better system performances. RF MEMS electro-acoustic high Q resonators are a good example of this category.

Embedding power sources with the electronics:Several new applications will require on-chip or in-package micro power sources (autonomous sensors or circuits with permanent active security monitoring for instance). Energy scavenging micro-sources or micro-batteries are examples of this category.

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Why organic electronics ?

• Easy to process (low costs)

• Large area application

• Flexible substrates

• Chemical tunability of conjugated polymers (absorption spectrum)

• Easy integration in different devices

• Ecological and economic advantages

Example of organic sheet-image scanner

Inkjet-Printed solar cell from KonarkaOLED Display For Mp3-player OLED TV from Sony

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IV-Characteristics BHJ OPV

1,00E-06

1,00E-05

1,00E-04

1,00E-03

1,00E-02

1,00E-01

1,00E+00

1,00E+01

1,00E+02

-4,0 -3,0 -2,0 -1,0 0,0 1,0 2,0

V

I [m

A/c

m2]

Dark

Illuminated

P3HT

PCBMTop Electrode

P3HT:PCBM Blend

PEDOT:PSS

ITO

Substrate

Organic Photodetectors on glass

• OPD with on/off ratio of more than 104 @ -1 V

ITO/PEDOT:PSS/P3HT:PCBM/LiF/AL

0.6 nm LiF, 100 nm Al

140 nm P3HT:PCBM (1:1)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

500 550 600 650 700 750 800 850

Wavelength [nm]

Am

pli

tud

e [n

orm

aliz

ed]

Bulk heterojunction photodetector

S. Tedde et al., Fully Spray Coated Organic Photodiodes, Nano Letters 9 (3), 980 (2009)

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Organic Photodetectors on plastic

In collaboration with Siemens CT MM1

Multibarrier PET Foil

Au or ITO PEDOT:PSS

P3HT:PCBM blend

CaAg

Thin Film Encap.

I/V

400 500 600 700 8000

20

40

60

80

100

85% @ 550nm

EQ

E [

%]

Wavelength [nm]

The combination of organic semiconductors with a CMOS-chip offers advantages compared with a conventional CMOS-sensor:

high photosensitivity -> fill factors up to 100 % wavelength tunability -> sensors for infrared/ultraviolet region inexpensive fabrication subwavelength grading for optimized performance and polarization

sensitivity

PCBM:P3HT

glass-substrate

ITO

Al 100 nm

PEDOT

LiF 1nm

ITO 100 nm

Requirements for combination CMOS-organic:

work function of the metallization of CMOS chip must be aligned to organic semiconductor energy levels -> e.g. Aluminium

deposition process of organic semiconductors should be possible on rough/patterned surfaces

Standard organic photodetector

Integration with CMOS

In collaboration with Uni. Trento and Fondazione Bruno Kessler 30

-4 -3 -2 -1 0 1 2

1E-7

1E-6

1E-5

1E-4

1E-3

0.01

0.1

1

10

inverted diode (dark/light=100 mW/cm²)

noninverted

Cur

rent

den

sity

(m

A/c

m²)

Voltage (V)

300 400 500 600 700 800 900 100005

10152025303540455055606570

Tra

nsm

issi

on(%

)

wave length (nm)

IV-curves (dark/light):

on/off-ratio can be even better than of standard device

lower dark current

lower light current (due to higher absorbance of gold electrode compared with ITO)

higher serial resistance

Transmission of gold-electrode (20 nm)

Preliminary results on inverted structure

D. Baierl et al., to be published in Organic Electronics 31

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Conclusions

Nanotechnology provides a variety of interesting and

promising nanostructures

Integration with CMOS will be the first step in the profitable

use of nanostructures, once process compatibility is proven

Critical issues such as reliability, stability and lifetime are

going to become routine and will have to be addressed at a

circuit/architecture level

Novel circuits and architectures are going to be needed for a

full exploitation of nanocomponents


Teaching activities Lectures

NANOLECTRONICS (6. Sem. Bach. EI)

NANOSYSTEMS (1. Sem. MSc. EI,)

MOLECULAR ELECTRONICS (2. Sem. MSc. EI)

COMPUTATIONAL METHOD IN NANOELECTRONICS (2. Sem. MSc. EI)

SEMICONDUCTOR QUANTUM DEVICES (1. Sem. MSc. EI)

NANOTECHNOLOGY (1. Sem. MSc. EI, MSc. “Microwave Engineering”,

MSc “Communication Engineering”, MSc. in “Engineering Physics”)

Labs

Nanoelectronics (6. Sem. Bach. EI.)

Simulation of semiconductor nanostructures (MSc. EI)

Characterization and simulation of molecular devices (MSc. EI.)

Design of molecular circuits (MSc. EI)

Nanobioelectronics (MSc. EI)


International Initiatives

Joint Bachelor Program in EE with Georgiatech

Joint Master Program NTU/TUM on "Integrated Circuit Design„

Joint Master Program NTU/TUM on „Microelectronics„

Int. Master in „Communication Engineering“ (section on „Comunication Electronics“)

Int. Master in „Nanoscience and Nanoengineering“ (starting 2011)

Joint Ph.D. Program (BI-NATIONALLY SUPERVISED DOCTORAL THESIS) with University of Trento (Italy)

Joint Ph.D. Program (BI-NATIONALLY SUPERVISED DOCTORAL THESIS) with Universita‘ delle Marche (Italy)

Research cooperations with several european and international companies, research labs and universities (STMicroelectronics, IBM, Arizona State University, MIT, Notre Dame University, University of Illinois U.C., Nanyang Technological University, Universita‘ di Roma „Tor Vergata“, Universita‘ di Modena, …)

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Bachelor EI (since Oct. 2008)

Menu „Nanoelectronics“ (30 Credits; 5. and 6. Semester)

Nanoelectronics 5 Sem 6 CreditsCMOS-Technologie 5 Sem 3 Credits Schaltungssimulation 5 Sem 3 CreditsPraktikum Elektronische Bauelemente 5 Sem 3 Credits

Nanotechnology 6 Sem 6 CreditsHalbleitersensoren 6 Sem 3 CreditsOptoelektronik 6 Sem 3 CreditsProjektpraktikum Nanoelektronik

und Nanotechnologie 6 Sem 3 Credits

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MSc EI (starting Oct. 2010)

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MS Communication Engineering

Mandatory Modules Sem.

Adaptive and Array Signal Processing 1

Broadband Communication Networks 1

Digital IC Design 1

Engineering Management 1

Information Theory and Source Coding 1

Advanced Topics in IC Design 2

Electronic Design Automation 2

Mixed Signal Electronics 3

Aspects of Integrated System Technology and Design 3

Testing of Digital Circuits 3

A paid internship of 10 weeks duration in a German company is intended for the semester break between the 2nd and the 3rd semester.

Elective Modules Sem.

Nanotechnology 1

Time-Varying Systems and Computations 1

Mobile Communications 1

Mathematical Methods of Information Technology 1

Advanced MOSFETs and Novel Devices 2

Image and Video Compression 2

HW/SW Codesign 2

Nanoelectronics 2

Physical Electronics 2

Advanced Network Architectures and Services 1 2

System on Chip Solutions in Networking 2

IC Manufacturing 3

MIMO Systems 3

Optimization in Communications and Signal Processing 3

Computational Methods in Nanoelectronics 3

Advanced Network Architectures and Services 2 3

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MS MicroWave Engineering

Mandatory Courses Sem.

Electromagnetics 1 1

Fundamentals in Communication Theory 1

Microwave Semiconductor Devices 1

Quantum Nanoelectronics 1

Integrated Systems 1


Advanced MOSFETs and Novel Devices 2

Nanoelectronics 2

Selected Topics in Nanotechnology 2


Nanotechnology 3

Computational Methods in Nanoelectronics 3

Seminar on Topics in RF-Engineering and Nanoelectronics

3

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MS Engineering Physics

Among the elective lectures in Material Science students can choose , among others,

“Semiconductor Nanoscience and Technology I”,“Bio- and Nanoelectronic Systems I and II”, “Introduction to surface and interface physics”,

as special physics lecture, or

“Molecular Electronics”, “Nanotechnology”, “Selected Topics in Nanotechnology”

as engineering lecture

Energy Science: provide a specialized education in Energy Science with lectures ranging from fission, fusion to all kinds of renewable energies.

Materials Science: dedicated education in Materials Science including lectures in bio-physics, low dimensional electronic systems, quantum optics, solid state spectroscopy and many more.

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International MS Programs in Singapore

A series of Joint International MS Programs are offered by TUM together with NTU :

Microelectronics Integrated Circuit Design Aerospace Engineering (from Aug. 2009)

and with NUS

Industrial Chemistry

in Singapore

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NTU-TUM MS Microelectronics

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NTU-TUM MS Microelectronics

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NTU-TUM MS Integrated Circuit Design

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PCP/SPUR Programme

Master Programmes under Professional Conversion Programme (PCP) with SPUR (Skills Programme for Upgrading and Resilience) funding

GIST and the Singapore Workforce Development Agency (WDA) are jointly rolling out four Master of Science programmes targeted at Professionals, Managers, Executives, Technicians (PMETs) who would like to convert or upgrade their skills under the Professional Conversion Programme (PCP). This coming May, the Master of Science in Integrated Circuit Design will commence for PMETs who are seeking a career in the Integrated Circuit Design industry. Trainees* need only pay net fees of *S$3210 (inclusive of GST) to get a world class education from leading Universities (NTU and TUM). Programmes which are offered under SPUR funding:

Master of Science in Industrial Chemistry TUM / NUSMaster of Science in Microelectronics TUM / NTUMaster of Science in Integrated Circuit Design TUM / NTUMaster of Science in Aerospace Engineering TUM / NTU

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MS Nanoscience and Nanoengineeringmodule name Sem ECTS

Physics for Nanoscience1 1 6

Circuit theory for Nanoscience2 1 6Materials and Chemistry for Nanoscience1 1 6

Signal processing2 1 6

Fundamental IT skills 1 3

Block Practical 1 3

Seminar 1 3

Electronics Lab 1 3

Management / Soft skills 1 6

Nanoscience 2 6

Advanced condensed matter 2 4Computational methods in nanoscience

2 5

Nano biotechnology 2 3

Intro. Organic Chemistry 2 3

Elective Modules 2 6

Advanced nanoscience seminar 2 3

Nanosystems 3 3

Nanoelectronics 3 3

Nanophotonics 3 3

Elective Modules 3 6

Project work / Internship 3 15

Masters Thesis 4 30

• International MS program in English • Initial selection of candidates

In the first semester, 12 credits will be devoted to the attempt of providing a common background for all. Thus, students with a Bachelor in Physics will be required to take two modules of basics engineering courses (2 in the table) while students with an EI Bachelor will take two basic physics modules (1 in the table).

Modules with 3 ECTS corresponds to a standard course with 2 hours lecture and 1 hour recitation. Modules with larger numbers of credits combine lectures with practical works, seminars or, in some cases, homework.

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Conclusions

Nanoelectronics is slowly entering the EE curricula at both

Bachelor and MS level

Interdepartment and interfaculty curricula are necessary,

especially between EE, Physics, Material Science, Chemistry and

Biology

Very interesting opportunities offered by international

cooperations

Great potentials for nanoelectronics in the areas of energy,

medicine and automation, both for teaching and research

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Thanks for your attention!

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AcknowledgmentsCentre forNanotechnology andNanomaterials

Institute for Nanoelectronics

nano

MDM

UTor Vergata

Documents

Teaching Nanoelectronics