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Page 1: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

Somerset, NJ, May 1, 1993

Page 2: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

53rd AVS,San Francisco November 2006

Page 3: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

San Francisco Bay,November 2006

Page 4: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

… celebrating Ted’s 70th birthday…

Rutgers University,February 16, 2008

Page 5: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

ca. 50 papers (many of which are highly-cited) on oxides or related topics.

Ted Madey and Oxide Surfaces:

Page 6: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

Bertel

Page 7: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

7

Resonant photoemission:

Auger Electron

Ti4+

Ti(3p)

VB

Direct Photolectron

Ti4+

Ti(3p)

VB

Page 8: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

Electron Stimulated O+ Emission from TiO2

Conduction BandAuger Electrons

Fermi level

Ti4+ O2-

O(2s)

Ti(3p)

VB

Knotek and Feibelman, PRL 40 (1978) 964

Knotek-Feibelman model:

ESDIAD from TiO2:R.L. Kurtz, R. Stockbauer, and T.E. Madey“Angular Distribution of Ions Desorbing from TiO2”Nucl. Instr. Meth. B 13 (1986) 518

Page 9: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

TiO2(110)point defect

Ti(5)O(3)

O(2)

R.L. Kurtz, R. Stockbauer, and T.E. Madey, “Synchrotron Radiation Studies of H2O Adsorption on TiO2(110)”, Surf. Sci. 218 (1989) 178;

J.-M. Pan, B.L. Maschhoff, U.D., and T.E. Madey, “Interaction of water, oxygen, and hydrogen with TiO2(110) having different defect densities”, JVST B 10 (1992) 2470

(Combined >400 citations)

Adsorption of Water on TiO2(110):

Page 10: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

U. D., J.-M. Pan, and T.E. Madey"Ultrathin Metal Films on TiO2(110): An Overview"

Surface Science, Volume 331-333 (1995) 845

Page 11: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

EUV

Extreme UV Lithography(= 13.4 nm)

S. Bajts, N.V. Edwards, and T.E. Madey, “Properties of ultrathin films appropriate for optics capping layers exposed to high energy photon irradiation” Surf. Sci. Rep. 63 (2007) 73

Mirrors: Si/Mo multilayersMirrors: Si/Mo multilayers

Page 12: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

EU

V

HCx

H2O

surface carbon growth surface, sub-surface oxidation

Cap layer

EUV mirror contamination mechanismsEUV mirror contamination mechanisms

13.5 nm, 92eV

12

(Collaboration: Fraunhofer Institut für Angewandte Optik und Feinmechanik, National Institute of Standards, Rutgers University, Tulane University, Intel)

Page 13: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

Theodore E. Madey, Boris Yakshinskiy, M. Nejib Hedhili, Shimon Zalkind

Page 14: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

4. Mitigation for MMA/TiO2 at 300K( oxygen and electron-irradiation: 100µA, 100eV)

0 2 4 6 8 10 12 14 16 18 200.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 100 200 300 400 500 600

0.01

0.1

1

C film growth, nm / hr

P(O2) / P(MMA) ratio

P(O2)=1.5x10-6 Torr

P(MMA)~10-8 Torr

No oxygen

P(MMA)~10-8 Torr

T=300KIel=100 μA,Eel=100eV

P(O2)=3x10-7Torr

P(MMA)~5x10-10Torr

P(O2)=3x10-6Torr

P(MMA)~10-8Torr ( )C film thickness nm

Electronfluence(×1018el/cm2)

P(O2)=3x10-7Torr

P(MMA)~10-8Torr

Oxygenoff

MitigationeffectsforMMA/TiO2

O2 is effective mitigating agent for TiO2

Theodore E. Madey, Boris Yakshinskiy, M. Nejib Hedhili, Shimon Zalkind

Page 15: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

Surface Science with no the pressure gap:

Page 16: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

Electron-stimulated desorption of oxygen from TiO2(011)-2x1

Dec. 2005

Page 17: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

O(3)Ti(5)

O(1) - ‘titanyl groups’’

O(3)

T.J. Beck et al., PRL 93 (3) (2004) 036104; Di Valentin et al., JACS 2005;Beck et al, Surf. Sci. Lett, 2005; Dulub et al., Surf. Sci, 2006

TiO2(011)-2x1:

?

Rutile TiO2

(Equilibrium Crystal Shape)

Ramamoorthy and VanderbiltPhys. Rev. B 49, 16721 (1994)

Page 18: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

T.J. Beck et al., PRL 93 (3) (2004) 036104; Di Valentin et al., JACS 2005;Beck et al, Surf. Sci. Lett, 2005; Dulub et al., Surf. Sci, 2006

TiO2(011)-2x1:

‘Brookite-like’ model (XQ Gong et al, Surf Sci 2008)

Rutile TiO2

(Equilibrium Crystal Shape)

Ramamoorthy and VanderbiltPhys. Rev. B 49, 16721 (1994)

Page 19: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

Electron Stimulated Desorption Ion Angular Distribution (ESDIAD) from TiO2(011)-(2x1)

[100] 300 eV

O+ O+[100]

[011

]

Conduction BandAuger Electrons

Fermi level

Ti4+ O2-

O(2s)

Ti(3p)

VB

Knotek and Feibelman, PRL 40 (1978) 964

Knotek-Feibelman model:

Page 20: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

40 mine-

1.8 x 1017 e/cm2

70%

20 min e- 9.2 x 1016 e/cm2

55%

2.3 x 1016 e/cm25 min e-

35%

before

4%

STM of TiO2(011)-(2x1) after electron bombardment

Zig-zag atoms (O atoms) disappear rapidly with electron bombardment (high cross section).

Thermally induced O-vac. defects.

One-dimensional rows of O atoms instead of zig-zag arrangement.

O. Dulub, M. Batzill, S. Solovev, E. Loginova, A. Alchagirov, T. E. Madey, and U. Diebold,

Science 317 (2007) 1052 – 1056

Page 21: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

The effect of electron bombardment on the defect structure of TiO2(011)-(2x1)

Clean TiO2(011) surface before irradiation. Density of oxygen vacancies is ~ 4%

9.2 x 1016 e/cm255% vacancies

Page 22: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

Site-specific cross sections for electron stimulated desorption:

D = 9.2 x 1016 e/cm2N = 55% vacancies experiment

Once a defect is created, the desorption probabilities for the four neighboring atoms are adjusted

1/20 1/20 1/2000 1/2000

1/20 1/200 1/200

Modeled defect configuration:

Quenching of electronic excitation by defect state

Page 23: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

Site-specific cross sections for electron stimulated desorption:

D = 9.2 x 1016 e/cm2N = 55% vacancies experiment

(1/20) = 1.2 x 10-16 cm21/20 1/20 1/2000 1/2000

1/20 1/200 1/200 (1/200) = 1.2 x 10-17 cm2

(1/2000) = 1.2 x 10-18 cm2

n = Pn A

P - desorption probability A - area per surface O atom (25 Å2)

Quenching of electronic excitation by defect state

O. Dulub, M. Batzill, S. Solovev, E. Loginova, A. Alchagirov, T. E. Madey, and U. Diebold,

Science 317 (2007) 1052 – 1056

Page 24: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

Lessons I learned from working with Ted:

• Enjoy what you do.• Pay attention to details.• “Published means forever” - write well!• Prepare your talks.• Pay attention at conferences.• Read.• Read.• Read.• You can be successful in science, AND a good person.

Page 25: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.
Page 26: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.

Your students,and your students’

students, and their

students…

We will always remember you, Ted.

Page 27: Somerset, NJ, May 1, 1993. 53 rd AVS, San Francisco November 2006.