12 October 2012

Tehnici nanolitografice pentru fabricarea

dispozitivelor nanoelectronice

Adrian Dinescu, IMT Bucuresti

Workshop “Parteneriat pentru inovare: cercetare – industria electronica”

18 October 2012

Nanoscale Structuring and Characterization Laboratory

Raith e_Line - dedicated EBL equipmentNanoInk Nscriptor – dip pen nanolithography

NT-MDT Ntegra Aura AFM & STM

Tescan Vega LMU II

Thermionic (tungsten) SEM

FEI Nova NanoSEM630

FEG-SEM

Agilent G200 - Nanoindenter

18 October 2012

First EBL equipment in IMT - Tescan Vega LMU II and Raith Elphy Plus – installation 2006 Raith e-Line – installation 2008

150nm

30nm diameter holes in PMMA 950k 10nm diameter holes in PMMA 950k

Smallest beam diameter : 5nm @ 3pA beam current and 30kV

Smallest beam diameter: 1.5nm @ 200pA

Electron Beam Lithography equipment in IMT Bucharest

100nm

18 October 2012

Mix and match lithography: photolitography & EBL

600µm200µm

18 October 2012

Acoustic devices for GHz applications

Acoustic resonators

A.Muller, D. Neculoiu, G. Constantinidis, G. Deligeorgis, A. Dinescu, A. Stavrinidis, A. Cismaru, M. Dragoman and A. Stefanescu,

„ SAW Devices manufactured on GaN/Si for frequencies beyond 5GHz”, IEEE Electron Device Letters, Vol. 31, No. 12, Dec. 2010

D. Neculoiu, A. Müller, G. Deligeorgis, A. Dinescu, A. Stavrinidis, D. Vasilache, A. Cismaru, G. E. Stan and G. Konstantinidis,

“AlN on silicon based surface acoustic wave resonators operating at 5 GHz”, Electronics Letters, vol 45, No 23, 2009

18 October 2012

SAW devices for microwave applications (1)

AlN/Si

•Deposition by magnetron sputtering

•Sound velocity 6000 m/s

•Coupling coefficient 6%

•Deposition by MBE and MOCVD

•Sound velocity 5000 m/s

•Coupling coefficient 2%

•Monolithic integration with HEMT transistors is possible

SAWsHEMTs

GaN/Si

Collaboration IMT Bucharest – FORTH IESL Heraklion, Grece

18 October 2012

SAW devices for microwave applications (2)

GDSII layout for contact pads and alignment marks

Wafer patterned with Cr/Au contact pads

GDSII layout of the IDTs

IDTs patterned in PMMA 950kSAW resonator after

metallization and lift off

Detail of Ti/Au nanoelectrodes

Photolithography Metallization

(Cr/Au)Lift off

+

EBL

E-beam evaporation (Ti/Au)

Lift off

18 October 2012

D. Neculoiu, A. Müller, G. Deligeorgis, A. Dinescu, A. Stavrinidis, D. Vasilache, A. Cismaru, G. E. Stan and G.

Konstantinidis, “AlN on silicon based Surface Acoustic Wave resonators operating at 5 GHz”

Electron. Lett. 45, 1196 (2009)Electron. Lett. 45, 1196 (2009)Best previous result obtained before was a SAW on

AlN (but on diamond not on silicon) operating at 4.5

GHz [P. Kirsch et al. Appl Phys. Lett.88, 223504,

2006]

4.6 4.8 5 5.2 5.4

frequency, GHz

-70

-65

-60

-55

-50

-45

-40

S21, dB

Results 2009Results 2009

Resonance > Resonance > 5GHz on 5GHz on AlNAlN

SAW devices for microwave applications (5)

18 October 2012

SAW devices for microwave applications (6)

Results 2010 Results 2010

Resonance > Resonance > 5GHz on 5GHz on GaNGaN

The highest resonance frequency reported for a SAW structure on GaN (on sapphire) is

2.225 GHz, with the interdigitated transducer (IDT) having 600-nm-wide fingers and

spacings: T. Palacios, F. Calle, E. Monroy, and F. Munoz, “Submicron technologyfor III-

nitride semiconductors,” J. Vac. Sci. Technol. B, Microelectron. Process. Phenom., vol.

20, no. 5, pp. 2071–2074, Sep. 2002.

A.Muller; D.Neculoiu; G.Konstantinidis; G. Deligeorgis; A. Dinescu; A. Stavrinidis; A. Cismaru; M.Dragoman; A.Stefanescu; “SAW Devices Manufactured on GaN/Si for Frequencies Beyond 5 GHz “

IEEE ELECTRON DEVICE LETTERS IEEE ELECTRON DEVICE LETTERS Volume: 31 Issue: 12 Pages: Volume: 31 Issue: 12 Pages:

13981398--1400 1400 (2010)(2010)

SEM micrograph of the test structure. The distance between the IDTs was d = 20 µm;

for the other test structures, it was d = 100, 200, and 600 µm.

Measured reflection losses (S11) versus the frequency for threestructures with different distances between the IDTs compared with the electromagnetic simulated results (without the inclusion of the piezoelectric effect).Detail of the nanolithographic process with fingers and interdigits which are

nominally 200-nm wide, developed on the GaN surface.

(a) SEM photograph. (b) AFM image.

18 October 2012

SAW, single resonator; length 100 µm IDTs, digit/interdigit spacing 0.2 µm; Distance between reflectors and IDTs: d= 0.95 µm;IDT: 100 fingers/interdigits ; reflectors 60 digits /interdigitsGaN/Si; GaN layer 1 µm thinIDT and reflectors 0.1 µm thin Au

Sensitivity ~ 356.9 kHz/°C = 65 ppm/°C

Q = 400

SAW devices for microwave applications (7)

SmartPower - Smart integration of GaN & SiC high power electronics for industrial

and RF applications. (www.smart-power.com)Experiments to prove the concept of monolithic integration of MMIC and GaN T sensor.

18 October 2012

1. A.Muller, G. Konstantinidis, M. Dragoman, D. Neculoiu, A. Dinescu, M. Androulidaki, M. Kayambaki, A. Stavrinidis, D. Vasilache, C. Buiculescu, I. Petrini, A. Kostopoulos and

D. Dascalu, “GaN Membrane-supported UV Photodetector manufactured using nanolithographic process” , Microelectronics Journal; ,40,2009, p 319-321.

2. A. Müller, G. Konstantinidis, M. Androulidaki, A. Dinescu, A. Stefanescu , A. Cismaru , D. Neculoiu , E. Pavelescu, A. Stavrinidis, “Front and backside-illuminated GaN/Si

based metal–semiconductor–metal ultraviolet photodetectors manufactured using micromachining and nano-lithographic technologies”, Thin Solid Films, 520 (2012) 2158–2161

Schematic cross-section of the membrane MSM UV detector structure.

Top view of the detector Detail of the interdigitated contacts

a) Responsivity vs wavelength for the 0.5µm finger/interdigit UV GaN detector before the silicon substrate removal.

b) Responsivity vs wavelengthfor the 0.5 µm finger/interdigit UV detectorst manufactured on thin GaN membrane.

MSM photodetectors on silicon supported GaN membranes

18 October 2012

E. Budianu, M. Purica, A. Dinescu, E. Manea “Metal-Semiconductor-Metal photodetector on silicon insulating wafersbased on nanoscale interdigitated electrodes”, EMRS Fall meeting 2009, September 14-18, Warsaw, Poland

Schematic cross-section of the membrane MSM UV detector structure.

MSM photodetectors on silicon

18 October 2012

EBL for graphene based devices

Inte

nsi

ty (

a. u.)

1 500 2 000 2 500 3 000 3 500 4 000Raman shift (cm-1)

26

40

.7

15

86

.1

Inte

nsi

ty (

a. u.)

1 500 2 000 2 500 3 000 3 500 4 000Raman shift (cm-1)

26

57

.6 15

83

.2

Inte

nsi

ty (

a. u

.)

1 500 2 000 2 500 3 000 3 500 4 000Raman shift (cm-1)

2656.7

1581.0

Raman spectra of a few selected points of graphene flake used for FET fabricationSubstrate: p++ silicon, boron doped, resistivity 0.005 Ωcm, covered with 300nm dry thermal oxide

MLG BLG SLG

AFM image of the SLG

Equipment: NT-MDT N-Tegra Aura

A.C. Ferrari et. al., Pyhs. Rev. Lett. 97 , 187401 (2006)

18 October 2012

SLG areas surrounded by alignment marks

18 October 2012

Patterned electrical contacts on graphene flakes

18 October 2012

CPW structures on SLG

18 October 2012

E-beam lithography patterning of graphene flake

RIE etching (oxygen plasma) of graphene flake

Electron resist deposition

EBL exposure

RIE (oxygen plasma)

Electron resist removal

Cutting process for SLG

- Electronresist

-SLG

-Silicon dioxide

-Silicon

18 October 2012

Electrical contacts for source and drain fabricated by e-beam lithography, metal evaporation (Ti/Au- 5-30nm), and lift-off

Inte

nsi

ty (

a. u.)

1 500 2 000 2 500 3 000 3 500 4 000Raman shift (cm-1)

1588.1

2642.8

18 October 2012

Graphene ribbonsPristine SLG

Graphene patterned for RIE

Patterning in the PMMA before metal coating The structre with 20 transistors after lift-off

A back gated FET on graphene ribbon

Array of 17 back gated FETs on graphene ribbons

18 October 2012

The device under test, on the probing stationSemiconductor Characterization System - 4200-SCS/C/Keithleywith Wafer Probing Station –Easyprobe EP6/ Suss MicroTec

0

2

4

6

8

10

12

14

-40 -30 -20 -10 0 10 20 30 40

Back gate voltage (V)

Rds (kΩ)

0

10

20

30

40

50

60

70

80

0 200 400 600 800 1000 1200

Dose (µC/cm2)

Rd

s i

n t

he

CN

P (

kΩ

)

Rds in the CNP vs irradiation dose (HV = 200V)

Similar behavior at 500V and 1kV

18 October 2012L. Gence, V. Callegari, A Dinescu, S. Melinte and S. Demoustier-Champagne, “Hybrid Polymer nanowire based electronic devices correlated characterization”

14-th International Conference of Modulated Semiconductor Structures (MSS 14), 19-24 July 2009, Kobe, Japan

EBID module

SEM micrographs showing platinum lines connecting a polymer nanowire to the electrical pads

18 October 2012

Structure used for electrical characterization of CNTs at high frequencies. EBL was used for patterning the small calibration line and EBID technique for fixing the CNTs

Platinum deposition was used for fixing the CNTs across V-shaped trenches in order to measure their mechanical properties

• Project: Carbon nAnotube Technology for High-speed nExt-geneRation nano-InterconNEcts – CATHERINE (FP7/STREP, 2008-2010)