Surface Plasmon Polarltions and Determination of Complex Dielectri c Permittivity and Thickness of thin Metal (Semiconductor) Films
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Date
1989-06
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Addis Ababa University
Abstract
Surface plasmon-pola r itons ( S21P) 100:' c.h c. .. . n be ~Jr.C. i.1 .e.o 'JO , ., ..
diel~c tric/, le t.::l (d i clcrtrich;emiconduc tor) interlace ca n be used a s;
hi ghl } se n sitiy~ non dis tructive probe for the de t ermination of the
die l e ct r ic consto.n t t: (w) - E: I (w) + t e" (w) and th i ckness h of a me t a l
semi conductor) f ilm wi t hou t a pr e set expression for f eW).
The t heo r e tical background of t he method [3] i s baf:ed on the
s ol ution of the Maxwell ' s equationa whi ch provides the dlspe rssion
equa tion of SPIP at t he surface of a thin meta l ( s emiconductor) film
and i t s i n t erpretat ion i n t er~s of at t enuated t o t a l r eflec tion (ATR)
cha rac terist i c s . The physical sense of : ne solution Is demons t r a t ed
t hr ough t he power flows and the field d i::;';r!.butions of SPIP an.d o t he r
pos s ~ble e xc i tations .
It i s s hoW_t .:hat [or str.lng absorbing meta l s (semi conduc t o r s)
l ow r2.oi a t i ve SPIP can exi&t at: f requencies higher than rh"!: pl aslna
fr eq-uenc y wp • . The aualYSJI> of the a ppr o:<!m.'lt e SOl u tion o r t he app r oxima t e
s o l u tion of dispers lon e quation f or th::l.n me t al (semic onductor) f 11. [3]
e s t ablished a well-def i ned l i mited f r equency ~8nge of its ap plicabil i t y.
It was found that Lhc upper frequency limi t de pends upon the thickness
of the f i lm and fa:ls down fr.)m W
p/t2
co - 0.35 Wp as h+O.
A computer model simulating rea lis t ic e xpe r i menta l c onditions of
measurement ATR character is tics is discussed. The accuracy of Cl (W).
c " (w) and h determinat ion is establis hed.
Description
Keywords
Surface plasmon-pola r itons