simultaneous reflection and transmission measurements of scandium oxide thin films in the extreme...

Simultaneous Reflection and Transmission Measurements of Scandium Oxide Thin

Films in the Extreme Ultraviolet

Guillermo Acosta

Dr. David Allred

Dr. R. Steven Turley

Niki Farnsworth

Jed Johnson

Department of Physics and AstronomyBrigham Young University

Provo, Utah

My most sincere thanks…My most sincere thanks…

Mr. W. Lifferth, Mr. M. Erickson, Mr. W. S. Daniel, Mr. J. Ellsworth

Nan Ah You and the Physics Department Front Office Staff

WAESO and MGE@MSA Rocky Mountain NASA Space Grant

Consortium

Mr. W. Lifferth, Mr. M. Erickson, Mr. W. S. Daniel, Mr. J. Ellsworth

Nan Ah You and the Physics Department Front Office Staff

WAESO and MGE@MSA Rocky Mountain NASA Space Grant

Consortium

We measure thin films in the extreme ultraviolet

We measure thin films in the extreme ultraviolet

Measurements are made at Advanced Light Source, Lawrence Berkeley National Laboratory

Preferred technique for collecting transmission data is a thin film deposited on a photodiode (Seely, Korde, SPIE Meeting 1999; Seely, Uspenskii, J. Opt. Soc. Am 2004)

β(ω) can be found from transmission data, and reflection data can be used to find δ(ω).

Measurements are made at Advanced Light Source, Lawrence Berkeley National Laboratory

Preferred technique for collecting transmission data is a thin film deposited on a photodiode (Seely, Korde, SPIE Meeting 1999; Seely, Uspenskii, J. Opt. Soc. Am 2004)

β(ω) can be found from transmission data, and reflection data can be used to find δ(ω).

photodiode

coated photodiode

transmission measurement

reflection measurement

Energy can only go three places:

Transmitted, Reflected, Absorbed

Energy can only go three places:

Transmitted, Reflected, Absorbed

Sometimes…Sometimes…

Samples are not uniform Photodiode does not have absolute uniform

response Beam intensity changes Short on time

Samples are not uniform Photodiode does not have absolute uniform

response Beam intensity changes Short on time

Collect transmission and reflection data simultaneously

Collect transmission and reflection data simultaneously

Measurements would be from exactly the same spot of the sample.

Twice as much data, strongly correlated allows for more robust model

Optimize beam time

Measurements would be from exactly the same spot of the sample.

Twice as much data, strongly correlated allows for more robust model

Optimize beam time

A New StageA New Stage

Essentially all angles availableEssentially all angles available

The migrating peaks in the reflection data are interference

fringes.

Bragg’s Law m* =d*sin

and are known.

The migrating peaks in the reflection data are interference

fringes.

Bragg’s Law m* =d*sin

and are known.

26

27

28

Reflectance of Scandium Oxide Thin Film

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

2.70 2.95 3.20 3.45 3.70 3.95 4.20 4.45 4.70

Wavelength (nm)

Ref

lect

ance

(%

)

8.2 degrees10 degrees11.5 degrees14.5 degrees

29

Reflectance of Scandium Oxide Thin Film

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

2.70 2.95 3.20 3.45 3.70 3.95 4.20 4.45 4.70

Wavelength (nm)

Ref

lect

ance

(%

)

8.2 degrees10 degrees11.5 degrees14.5 degrees

30

Reflectance of Scandium Oxide Thin Film

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

2.70 2.95 3.20 3.45 3.70 3.95 4.20 4.45 4.70

Wavelength (nm)

Ref

lect

ance

(%

)

8.2 degrees10 degrees11.5 degrees14.5 degrees

31

Reflectance of Scandium Oxide Thin Film

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

2.70 2.95 3.20 3.45 3.70 3.95 4.20 4.45 4.70

Wavelength (nm)

Ref

lect

ance

(%

)

8.2 degrees10 degrees11.5 degrees14.5 degrees

32

Reflectance of Scandium Oxide Thin Film

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

2.70 2.95 3.20 3.45 3.70 3.95 4.20 4.45 4.70

Wavelength (nm)

Ref

lect

ance

(%

)

8.2 degrees10 degrees11.5 degrees14.5 degrees

33

The coincidence of maxima and minima from data collected at two different angles may allow

for the index of refraction to cancel out of equation.

This would only leave m and d as unknown.

The coincidence of maxima and minima from data collected at two different angles may allow

for the index of refraction to cancel out of equation.

This would only leave m and d as unknown.

Calculations of Scandium Oxide predict the L edge at 397.4 eV

Calculations of Scandium Oxide predict the L edge at 397.4 eV

Measurements show the edge at 402.6 eV

In conclusion…In conclusion…

Reflection and transmission data are collected from exactly the same portion of the sample

One set of physical parameters will be appropriate for analyzing both sets of data

Measurements of scandium oxide thin films are different from accepted predictions

Reflection and transmission data are collected from exactly the same portion of the sample

One set of physical parameters will be appropriate for analyzing both sets of data

Measurements of scandium oxide thin films are different from accepted predictions

Thank you.

acosta_g@hotmail.com

Thank you.

acosta_g@hotmail.com