AVS 50th International Symposium
    Semiconductors Thursday Sessions
       Session SC-ThM

Paper SC-ThM10
Strain Effects in Si-Ge Growth on Vicinal Si Surfaces Prepared by Laser Texturing

Thursday, November 6, 2003, 11:20 am, Room 326

Session: Heteroepitaxy and Strain Engineering
Presenter: F. Watanabe, University of Illinois at Urbana-Champaign
Authors: F. Watanabe, University of Illinois at Urbana-Champaign
D.G. Cahill, University of Illinois at Urbana-Champaign
J.R. Serrano, University of Illinois at Urbana-Champaign
S. Hong, University of Illinois at Urbana-Champaign
T. Spila, University of Illinois at Urbana-Champaign
J.E. Greene, University of Illinois at Urbana-Champaign
Correspondent: Click to Email
Growth of Si-Ge strained layers on Si substrates is of great interest because of its multiplicity of growth modes. These growth modes are a complicated function of temperature, alloy content, growth rate, and substrate vicinality. Laser texturing of Si provides contamination- and defect-free curved surfaces for our studies of how the morphology depends on vicinality. The surface features produced by fluid flow in the laser melt are approximately 5 µm in diameter and 200 nm in depth, and contain vicinal surfaces with orientations 0-10 degrees off (001). SiGe layers are grown by gas-source MBE. At high strain (~80% Ge), film growth is similar to that of 100% Ge, but the formation of dislocated islands at high coverage is less pronounced. At a growth temperature of 600 °C, nucleation of dome-shaped three dimensional islands takes place preferentially on vicinal surfaces with orientations within one degree of (001). Island nucleation is suppressed on surfaces oriented more than a degree off (001). At these higher vicinalities, ripple shaped morphologies form along <110> directions. The preferred regions for these instabilities are 5-10 degrees miscuts in the <110> directions inside and outside the laser dimples.