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Activitats en NanotecnologiesGrup de Dispositius, Sensors i Disseny VLSI

Eduard LlobetLluís F. Marsal

mic

rosy

stem

s nanotechnologies

for chemical

analysis

MMinoSinoS

mic

rosy

stem

s nanotechnologies

for chemical

analysis

MMinoSinoS

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Sub-línies

• MINOS: Microsystems and Nanotechnologies for Chemical Analysis (4 permanent, 2 RC, 1 JC, 9 PhD students)

– Nanosized metal oxide films for gas sensors

– CNT based gas sensors

– Porous alumina as template material

• NEPHOS: Nano Electronic and Photonic Systems ( 4 permanent, 1 RC, 1 JC, 8 PhD students)

– Modeling of nanoscale MOSFETs

– Porous and macroporous silicon

– Photonic crystals

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Projectes

• Desarrollo de tecnología para células solares fotovoltaicasTIC2002-4184-C02-02, 2003-2005

• SINANO E04003S

• EUROSOI E04002S

• Food Quality and Safety with Microsystems, GoodFood FP6-IST-1-508774-IP, 2003-2006

• Técnicas y tecnologías para el desarrollo de microsistemas analizadores de gases basados en agrupaciones integradas de sensores catalíticos TIC2003-06301, 2004-2006

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Modeling of nanoscale MOSFETs

• We have developed a physics-based compact model for ballistic nanoscale GAA MOSFETs which is based on Landauer’s transmission theory and incorporates the effects of multi-subband conduction.

• Scattering has been later incorporated to this model when used for DG MOSFETs.

• A compact model for Surrounding Gate MOSFETs under the drift-diffusion approximation has also been developed.

Cylindrical GAA witha 65 nm diameter Si film

Dotted line: measurementsSolid line: model0.2 0.4 0.6 0.8 1 1.2 1.4

0

5

10

15

20

Tra

nsco

nduc

tanc

e (

S)

T=70 mK

11E

VDS=2 mV

21E

12E 1

3E

11E

22E

21E 1

2E14E

13E 2

2E

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Porous-macroporous silicon

Silicon dioxide pillar arrays

Macropores with modulated pore diameter in depth

Silicon Oxide Microneedles

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Photonic crystals

J X J

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

T E

T M

9 0 m

7 0 m

4 0 m

1 0 m

9 0 m

1 0 m

m ic ro p o ro u s la y e r

Photonic band structure of air holes in silicon.

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Nanosized metal oxide films for gas sensors

• Ultra-thin films of metal oxides are grown by sputtering with interruptions.

No interr. 1 interr. 3 interr.

• As grain size diminishes, gas sensitivity increases.

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CNT based gas sensors

Characteristics:

– Catalytic carbon deposition method

– Purity > 95%

– Diameter:

• MWNT: 3 to 25 nm (outer diam.)

– Length:

• up to 50 m

MWNT functionalised in an RF inductively coupled oxygen plasma

Pur

e M

WN

TM

WN

T+

WO

3

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CNT based gas sensors

Response to NO2 of a pure MWNT sensor (functionalised with 20% at.

oxygen at the surface)

Response to NH3 of a WO3+MWNT sensor (functionalised with 10% at.

oxygen at the surface)

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Porous alumina as template material

Anodization of Al foils

Cu nanowires electroplated using a nanoporous alumina

template

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Publicacions rellevants

• Modeling of Nanoscale Gate-All-Around MOSFETs, IEEE Electron Device Letters, 2004

• Analysis of photonic band gaps in two-dimensional photonic crystals with rods covered by a thin interfacial layer, Phys. Rev.B, 2004

• Continuous analytic current-voltage model for surrounding gate MOSFETs, IEEE Electron Device Letters, 2004

• Effects of symmetry reduction in two-dimensional square and triangular lattices, Phys. Rev.B, 2004

• Detection of NO2 and NH3 with Oxygen Functionalised MWNT-based -hotplate gas sensors, Eurosensors XVIII, 2004 and submitted to Sensors Actuators B.

• New Technology of Metal Oxide Thin Film Preparation for Chemical Sensor Application, presented at E-MRS 2004 and submitted to Sensors Actuators B.