AVS 51st International Symposium
    Semiconductors Tuesday Sessions
       Session SC-TuA

Paper SC-TuA8
Silicon Nanocrystal Formation in an Oxide Matrix: Chemical and Strain Effects

Tuesday, November 16, 2004, 3:40 pm, Room 304C

Session: Semiconductor Heteroepitaxy and Nanostructures
Presenter: D. Yu, The University of Texas at Austin
Authors: D. Yu, The University of Texas at Austin
G.S. Hwang, The University of Texas at Austin
Correspondent: Click to Email
Nanocrystalline Si (nc-Si) embedded in an oxide matrix has received great attention due to its promising applications for advanced electronic and optical devices. The unique electrical and optical properties of oxide-embedded nc-Si appear to be strongly influenced by the crystallite size, shape, density, and oxide composition. It is therefore necessary to develop a detailed understanding of the nc-Si growth. We have developed a multiscale computational model for nc-Si synthesis in an oxide matrix by phase separation of silicon suboxide. This multiscale approach combines i) first principles quantum mechanics calculations of fundamental processes and ii) kinetic Monte Carlo simulations of long-time scale phase separation. Using the computational approach, we have identified formation mechanism of Si clusters in silicon suboxide. In this talk, first we will present fundamental processes involved in the phase separation including: i) Si interstitial behavior in an oxide and ii) O diffusion energetics which depends on strain and chemical environment. Based on these results, we will discuss the relative contribution of strain and suboxide penalty to the phase separation. Finally, we will present the process of Si particle formation, together with a comparison to experimental observations.