Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


J. Korean Phy. Soc. 2009; 55(2): 558-561

Published online August 14, 2009

Copyright © The Korean Physical Society.

Microscopic Characterization of Silicon Nanocrystals Formed byIn-situ Annealing

SungWon Hwang, DongHee Shin, SeungHui Hong, Suk-Ho Choi


Scanning tunneling microscopy (STM) and atomic force microscopy wereused for characterizing Si nanocrystals (NCs) embedded in SiO$_{2}$.The Si NCs were formed by {it in-situ} annealing of Si-rich oxide(SiO$_{x})$ films grown by ion beam sputtering. The thickness of theSiO$_{x}$ layers was 200 nm, and the annealing was done at 1165$^circ$C for 3 min. The sizes and the densities of the Si NCs wereestimated as 4 $sim $ 2.5 nm and 6.2 $ imes$ 10$^{11 }sim $ 3.4$ imes$ 10$^{12}$ cm$^{-2}$, respectively, for $x$ = 1.2 to 1.8,almost consistent with the high-resolution transmission electronmicroscopy (HRTEM) results. The photoluminescence peak of the Si NCsblueshifts from 1.44 to 1.63 eV as $x$ increases from 1.0 to 1.8, asexpected by the quantum confinement effect based the NC-sizevariation measured by using STM and HRTEM. These results demonstratethat STM is an accurate tool for characterizing the distributions ofsizes and densities for Si NCs.

Keywords: Silicon nanocrystals, Scanning tunneling microscopy, Atomic force microscopy, Photoluminescence