Experimental verification of dielectric constant decrease in silicon nanostructures

Han G. Yoo; Philippe M. Fauchet

doi:10.1117/12.767475

11 February 2008 Experimental verification of dielectric constant decrease in silicon nanostructures

Han G. Yoo, Philippe M. Fauchet

Proceedings Volume 6902, Quantum Dots, Particles, and Nanoclusters V; 690203 (2008) https://doi.org/10.1117/12.767475
Event: Integrated Optoelectronic Devices 2008, 2008, San Jose, California, United States

Abstract

During the design of devices using Si nanostructures, it is often important to precisely know the dielectric function ε, since it determines many of their electrical and optical properties. Several theoretical studies have predicted a reduction in the dielectric constant ε as the nanostructure size decreases. Two competing physical mechanisms have been proposed for the reduction: quantum confinement and surface effects (due to a breaking of polarizable bonds on the surface). There have been only a few experimental works on the size dependence of ε, in which ε was measured only for one particular average size. In our work, we have measured the size-dependent ε of thin crystalline slabs at different sizes using variable angle spectroscopic ellipsometry from 270 nm to 1700 nm at the incident angles of 65°, 70° and 75°. The thin crystalline slabs of different thicknesses (~ 15 nm to 2.5 nm) were fabricated by repeatedly subjecting the top Si layer of SOI wafers to plasma oxidation and BOE etching. Ellipsometry and surface profile measurements were performed between each etching step. At the wavelength of 1700 nm, for which silicon is transparent and bulk ε is 11.7, we found thatε was reduced to 7.5 for a 2.5 nm thick Si slab. Our results represent the first systematic measurement of the dielectric function of Si nanostructures as a function of size and represent the first test of the theories.

Citation Download Citation

Han G. Yoo and Philippe M. Fauchet "Experimental verification of dielectric constant decrease in silicon nanostructures", Proc. SPIE 6902, Quantum Dots, Particles, and Nanoclusters V, 690203 (11 February 2008); https://doi.org/10.1117/12.767475

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available