IMM Atom_based Nanotechnology workshop, 19 th January 2011, Arcetri (FI), Italy The network on...

IMM

Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy

The network on graphene at IMM

OUTLINE

• The IMM graphene research network• The agreement with Industry • Competences and acquired know how at IMM Agrate (MDM)• Competences and acquired know how at IMM CT

Slide 1/15

Istituto per la Microelettronica e Microsistemi

IMM


Bologna

Roma

Napoli

Lecce

Catania

Milano

The graphene research network at IMM

Graphene like materials (silicene, germanene, …) Memories and logics

Advanced characterisation & sensors See V. Morandi, R. Rizzoli

materials fundamentals & devices (Rf, power, …)

Slide 2/15

IMM


Bologna

Roma

Napoli

Lecce

Catania

Milano





Slide 3/15

IMM


Bologna

Roma

Napoli

Lecce

Catania

Milano





Slide 2/15

IMM


Bologna

Roma

Napoli

Lecce

Catania

Milano





The industrial cluster

3Sun

Slide 2/15

IMM


Bologna

Roma

Napoli

Lecce

Catania

Milano





The industrial cluster

3Sun

Slide 2/15

J.D.P.J.D.A.

J.D.A.

IMM


IMM-Agrate expertise on ReRAM memory devices Challenge: Resistive Random Access Memory

(ReRAM) in graphene.

EMMA Project-FP6 (1/9/2006-30/11/2009): Emerging Materials for Mass-storage Architectures (contact: Marco Fanciulli and Sabina Spiga)MORE Project 2010-2012 (CARIPLO): Advanced Metal-Oxide heterostructure for nanoscle ReRAM (contact: Sabina Spiga)

Top electrode

Bottom electrode

A

resistive material

Top electrode

Bottom electrode

ReRAM: a large class of emerging non-volatile memory concepts is based on a 2-terminal resistor as a memory

element that can be programmed in a high and low conductive state

Memristor concept introduced by HP

Large interest from worldwide industries on ReRAM for post high-density FLASH and for Flexible

Nonvolatile Memory Applications

Graphene Oxide Thin Films (as switching element) for Flexible Nonvolatile Memory applications H.Y. Jeong at al., Nanoletters 2010, 10, 4381–4386

single layer graphene as electrode on Nb-doped STO substrate for Pt/NiO/graphene nano-ReRAM

graphene

IMM-Agrate expertise up to now: NiO, Nb2O5, TiO2 based metal/oxide/metal thin film- and nanowire-

heterostructures

J. Y. Son et al., ACS Nano 4, 2010, 2655-2658

Slide 3/15

CNR- IMM- Agrate

IMM


MBE of Si on Ag(110), Ag(111) substratesRef. Aufray et al, Appl. Phys. Lett. 97, 223109 (2010);

Aufray et al, ibidem 96, 183102 (2010)

Option 1: silicene on metals, (in analogy with graphene)

Option 2: encapsulation silicene with 2D hexagonal dielectric lattices

Challenge: Graphene-like materials

graphite-like AlN 2D top lattice

graphite-like AlN 2D bottom lattice

functionalized silicene

Graphene like semiconductors (silicene, germanene) valuable option for active material in Post-CMOS

ditital logic devices and circuits

@ CNR-IMM (Lab. MDM)

• Molecular beam epitaxy apparatus for growth, functionalization amd in situ characterization of graphene like materials

• in situ SPM and spectroscopic diagnostic tools

• dielectric capping for prototypical MOS-like devices

Slide 4/15

CNR- IMM- Agrate

IMM


Synthesis methodsMechanical exfoliation of highly oriented pyrolityc graphite (HOPG)

High material quality: Low defects density,High mobility

Small sheets;Low production yield

Epitaxial graphene on SiC by controlled graphitisation of the surface at high temperatures (1500 –2000 °C) in inert gas ambient

Large area (wafer scale) sheets on semiconductor substrate

Substrate cost

Can be placed on different substrates:SiO2 , SiC, high-k dielectrics

Chemical exfoliation of highly oriented pyrolityc graphite (HOPG)

High production yield Small sheets;DefectsCan be placed on different substrates:

SiO2 , SiC, high-k dielectrics

growth methods

GRAPHENE at IMM-CT: highlights

More than 30 papers since 2005 by two groups (theory & Exp.)

Slide 5/15

S. Sonde, F. Giannazzo, V. Raineri, and E. Rimini, J. Vac. Sci. Technol. B 27, 868 (2009).S. Sonde, F. Giannazzo, V. Raineri, and E. Rimini, Phys. Status Solidi B, 1–4 (2010) S. Sonde, F. Giannazzo, V. Raineri, R. Yakimova, J.-R. Huntzinger, A. Tiberj, and J. Camassel, Phys. Rev. B 80, 241406(R) (2009).

IMM


Synthesis methodsMechanical exfoliation of highly oriented pyrolityc graphite (HOPG)

High material quality: Low defects density,High mobility

Small sheets;Low production yield

Epitaxial graphene on SiC by controlled graphitisation of the surface at high temperatures (1500 –2000 °C) in inert gas ambient

Large area (wafer scale) sheets on semiconductor substrate

Substrate cost

Can be placed on different substrates:SiO2 , SiC, high-k dielectrics

Chemical exfoliation of highly oriented pyrolityc graphite (HOPG)

High production yield Small sheets;DefectsCan be placed on different substrates:

SiO2 , SiC, high-k dielectrics

growth methods

GRAPHENE at IMM-CT: highlights

More than 30 papers since 2005 by two groups (theory & Exp.)

Slide 5/15

S. Sonde, F. Giannazzo, V. Raineri, and E. Rimini, J. Vac. Sci. Technol. B 27, 868 (2009).S. Sonde, F. Giannazzo, V. Raineri, and E. Rimini, Phys. Status Solidi B, 1–4 (2010) S. Sonde, F. Giannazzo, V. Raineri, R. Yakimova, J.-R. Huntzinger, A. Tiberj, and J. Camassel, Phys. Rev. B 80, 241406(R) (2009).

BEYOND STATE OF THE ART

First EG on 4H-SiC off axis

Patended substrates

High mobility

IMM


GRAPHENE at IMM-CT: Highlights

Transfer to substrates: methods and functionalization

Slide 6/15

Silanization of SiOSilanization of SiO2 2

Phosphonization of SiOPhosphonization of SiO2 2

Transfer by Transfer by nanoimprintingnanoimprinting

Few -layers graphene on m etalFew -layers graphene on m etal

IMM



Transfer to substrates: methods and functionalization

Slide 6/15

Silanization of SiOSilanization of SiO2 2

Phosphonization of SiOPhosphonization of SiO2 2

Transfer by Transfer by nanoimprintingnanoimprinting

Few -layers graphene on m etalFew -layers graphene on m etal

CHALLENGES • From nanoscale properties to large area EG on 4H-SiC (150 mm)• Functionalisation (to control the G carrier concentration,

to control the G layer transfer to other substrates)

IMM


Quantum capacitance and local transport


Qdepl

SCM Electronic Module

+ Vg

n+ SiCn+ SiC

n-SiCAeffQscrGraphene

Qdepl

Under the influence of electric field, 2DEG manifests itself as a capacitor, Quantum capacitor.

+ Vg

Gnd

C’q

C’depl

ΔVgr

ΔVdepl

0 .0 0 .5 1 .0 1 .5 2 .01 0

-4

1 0-3

1 0-2

1 0-1

1 0 0

SiO 2

G ra p h e n e

C

(a

.u.)

V g (V )

0.0 0.5 1.0 1.50

5

10

15

20

25

Ae

ff (×1

04 nm

2)

n (×10 1 1 cm-2 )

0 10 20 30 400

100

200

300

l eff (

nm)

n (× 106 m -1)

SiO

SiC

leffAeff

F. Giannazzo, S. Sonde, V. Raineri, E. Rimini, Nano Lett. 9, 23 (2009).F. Giannazzo, S. Sonde, V. Raineri, and E. Rimini, Appl. Phys. Lett. 95, 263109 (2009).

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IMM


GRAPHENE at IMM-CT: HighlightsThe role of interfaces on mobility

104

10 5

10 6DG -SiC

SPP

ci

equi

exp10 4

10 5

10 6EG -SiC

cm

2 /Vs

0.5 1.0 1.5

10 4

105

10 6DG -SiO 2

nV g-n0 (×101 1 cm 2 /VS)

Nci_EG=2.5x1011cm-2

23000 cm2V-1s-1

Epitaxial graphene

Slide 8/15

Giannazzo F, Roccaforte F, Raineri V, Liotta SF, Europhys. Lett., 74, 686 (2006)

S. Sonde, F. Giannazzo, C. Vecchio, V. Raineri, E. Rimini, App. Phys. Lett., 97, 132101 (2010)Also selected for publication on Virtual Journal of Nanoscale Science & Technology.

IMM



From thin to fat FET

1 m1 m 60 nm

mnm

60 nm60 nm

mnm

1 m1 m 60 nm

mnm

60 nm60 nm

mnm

Atomic force microscopy

4H-SiC (0001) n+

4H-SiC (0001) n-EG

HSQ PtPt Pt

GateDrainSource

Lg=10m

Optical microscopy

Slide 9/15F. Giannazzo, C. Vecchio, V. Raineri, E. Rimini, submitted

IMM


-5 0 5 10

0.0

2.0x10-5

4.0x10-5

6.0x10-5

8.0x10-5

VD = 0 V VD = 0.2 V VD = 0.4 V VD = 0.6 V VD = 0.8 V

ID(A)

VG(V)

Transfer characteristicsHole conduction

Dirac point

Output characteristics0V < VD< 10V0V < VG< 14V

STEP = 1V

0 5 100.0

3.0x10-4

6.0x10-4

9.0x10-4

VG = 14 V

VG = 12 V VG = 10 V VG = 8 V VG = 6 V V

G = 4 V

VG = 2 V V

G = 0 V

I D(A

)

VD(V)Transconductance

-2 0 2 4 6 8 10 12 14-4.0x10

-6

-2.0x10-6

0.0

2.0x10-6

4.0x10-6

6.0x10-6

VG(V)

gm(S

)

VD = 0.8 V

VD = 0.6 V

VD = 0.4 V

VD = 0.2 V

VD = 0 V

Ambipolar transport

Electron conduction


fat FET characteristics

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IMM

Atom_based Nanotechnology workshop, 19th January 2011, Arcetri (FI), Italy Slide 11/15

0 10 20 300

1000

2000

3000

eff (

cm2 V

-1s-1

)

Vgs

(V) 0 20 40 60 80 1000

20

40

60

80

100

Fre

qu

en

cy (

%)

l (nm)

first processing end of processing

0 2000 4000 6000 80000

20

40

60

80

100

(cm2V-1s-1)

Mapping distribution

GRAPHENE at IMM-CT: challenges

IMM


CHALLENGES • Physical model nano- macro properties• New devices architectures

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0 10 20 300

1000

2000

3000

eff (

cm2 V

-1s-1

)

Vgs

(V) 0 20 40 60 80 1000

20

40

60

80

100

Fre

qu

en

cy (

%)

l (nm)

first processing end of processing

0 2000 4000 6000 80000

20

40

60

80

100

(cm2V-1s-1)

Mapping distribution

GRAPHENE at IMM-CT: challenges

Buried gate

New devices architectures

MIS inversion layer

FLGInsulator

Id

Vg>Vth

MIS inversion layer

FLGInsulator

Id

Vg>Vth

Rdrift

Rsource

CMIS

CMIS

CFLG

Rch,MIS RFLG

Vg

Rc,FLG-SiC

Vd

Rdrift

Rsource

CMIS

CMIS

CFLG

Rch,MIS RFLG

Vg

Rc,FLG-SiC

Vd

(a) (b)

(c)

Vg VgGateSource

Vd

Drain

n-typeSiC

n+-type

p-type

n+-typeFLG

InsulatorVg Vg

GateSource

Vd

Drain

n-typeSiC

n+-type

p-type

n+-typeFLG

InsulatorMIS inversion layer

FLGInsulator

Id

Vg>Vth

MIS inversion layer

FLGInsulator

Id

Vg>Vth

Rdrift

Rsource

CMIS

CMIS

CFLG

Rch,MIS RFLG

Vg

Rc,FLG-SiC

Vd

Rdrift

Rsource

CMIS

CMIS

CFLG

Rch,MIS RFLG

Vg

Rc,FLG-SiC

Vd

(a) (b)

(c)

Vg VgGateSource

Vd

Drain

n-typeSiC

n+-type

p-type

n+-typeFLG

InsulatorVg Vg

GateSource

Vd

Drain

n-typeSiC

n+-type

p-type

n+-typeFLG

Insulator

IMM


GRAPHENE at IMM-CT: ELECTRON STRUCTURE AND COHERENT TRANSPORT IN CONFINED GRAPHENE

Methodology

Electronic Structure Quantum transport

Ab initio Semiempirical

Density functional

theory, LDA and GGA exchange-correlation functionals, GAUSSIAN and SIESTA

codes

Tight-Binding (TB): single π-orbital Hamiltonian,

further parameterizations based on DFT

Extended Hückel Theory (EHT): real-orbital basis,

parameters from DFT calculations or

experimental data

Transport

Non-equilibrium Green’s functions methods coupled

to Landauer-Büttiker approach

Electrostatics

3D Poisson solver, computational box with

Neumann/Dirichlet boundary conditions

Slide 12/15

IMM


the simulation approach to transport propertiesPrevious activity overview Computation apparatus: self-consistent transport calculations Atomistic modeling of disorder in graphene based systems: from the single defect/impurity to a finite density of scattering centers GNR-metal junctionEpitaxial GNR on SiC(0001): role of interface statesFocus on defective and functionalized epitaxial GNR Complete device simulation

At CNR-IMM Catania• In house programming codes for

electronic structure and quantum transport based on atomistic semi-empirical Hamiltonians (Extended Hückel and Tight-Binding), NEGF-Poisson scheme

• Full-device simulation for 103 – 107 atoms (in the case of GNRs)

• Atomistic treatment of local alterations in the atomic structure, disorder, etc.

• Multiscale approach (electronic Hamiltonians calibrated or evaluated by first-principles calculations)

GRAPHENE at IMM: Highlights

Slide 13/15

A. La Magna et al, PRB 80, 195413 (2009) I. Deretzis and A. La Magna, Appl. Phys. Lett. 95, 063211 (2009)I. Deretzis et al., J. Phys. Cond. Mat. 22, 095504 (2010)I. Dertzis et al., Phys. Rev. B 81, 085427 (2010)I. Deretzis et al., Phys. Rev. B 82, 161413(R) (2010)I. D. and A. La Magna, accepted Appl. Phys. Lett.

IMM


IMM - CT • From nanoscale properties to large area (150 mm wafers)• Physical model considering nano-properties for macro-effects• New devices architectures• Functionalisation (to control the G carrier concentration,

to control the G layer transfer to other substrates) • Computational transport properties: multi scale approach

Slide 14/15

IMM - Agrate • Memories and logics in graphene• Graphene-like materials

IMM - Bo • see coming presentations for details

Challenges

IMM


Thank you for your attention

Catania:

Antonino La Magna*

Giuseppe Angilella**

Ioannis Deretzis***

Raffaella Lo Nigro*

Filippo Giannazzo*

Vito Raineri*

Emanuele Rimini**

Sushant Sonde***

Carmelo Vecchio ****

Agrate:

Marco Fanciulli**

Alessandro Molle*

Sabina Spiga*

Slide 15/15

* Ricercatori CNR di ruolo** Associati*** Post-doc**** Dottorandi

Bologna:

Vittorio Morandi*

Luca Ortolani***

Rita Rizzoli*

Giulio Paolo Veronese*

Alberto Roncaglia*

IMM Atom_based Nanotechnology workshop, 19 th January 2011, Arcetri (FI), Italy The network on...

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