Somerset, NJ, May 1, 1993

53rd AVS,San Francisco November 2006

San Francisco Bay,November 2006

… celebrating Ted’s 70th birthday…

Rutgers University,February 16, 2008

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

Ted Madey and Oxide Surfaces:

Bertel

7

Resonant photoemission:

Auger Electron

Ti4+

Ti(3p)

VB

Direct Photolectron

Ti4+

Ti(3p)

VB

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

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):

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

Surface Science, Volume 331-333 (1995) 845

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

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)

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

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

Surface Science with no the pressure gap:

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

Dec. 2005

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)

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)

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:

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

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

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

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

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.

Your students,and your students’

students, and their

students…

We will always remember you, Ted.