Plasmonic Nanolithography

EE235 Nanofabrication

Jie YaoApril 16, 2007

2 um

Z. Liu, et al, Nano. Lett. 5, 957, (2005)

W. Srituravanich, et al, Nano. Lett. 4, 1085 (2004)

Plasmonic NanolithographySurface plasmons (SPs) are collective free electron oscillations at a metal/dielectric interface

+ + + + + +

dielectric

metal1

2

E

Hy

kz

Kx Ez

zEz~e-|k

z|z

+ + + + + +

dielectric

metal1

2

E

Hy

kz

Kx Ez

zEz~e-|k

z|z

Main features of SPs

• Shorter wavelength (comparing with excitation light)• Evanescent wave enhancement• Bond to the surface• Propagation along the surface

• Shorter wavelength (comparing with excitation light)• Evanescent wave enhancement• Bond to the surface• Propagation along the surface

H. Raether, Surface Plasmons, (1988).

Higherresolution lithography

Light

Surface Plasmons

Plasmonic Lithography

Hole array lithography

W. Srituravanich, et al, Nano. Lett. 4, 1085 (2004)

Surface Plasmon Interference

GlassAl

|E|

Surface Plasmon Interference Nanolithography(SPIN)

PR

substrate

Z. Liu, et al, Nano. Lett. 5, 957, (2005)

Al 00.5(a)

λ0=365nm

2 um

PhotoresistAl

Quartz Quartz

PhotoresistAl

2 um

(b)

(c)

(d)

(e)

Period ~115 nm

Lithography Results (1D)

μm

(nm)~118nm

3μm

24

68

μm

(a) (b)

(c)

Lithography Results

Low reflectivity from the slit slit distance doesn’t affect the pattern quality

~60nm

2D SP Interference Lithography

(c)

(a)

(a’)

(b)

(b’)

(c)

(c’)

(d)

(d’)

• The interference pattern is determined by the arrangement of the SP sources

• The resolution is determined by the SP wavelength

Thank you

Questions?