Mechanisms determining three-dimensional SiGe lsland density on Si(001) |
| |
Authors: | J S Sullivan H Evans D E Savage M R Wilson M G Lagally |
| |
Affiliation: | (1) University of Wisconsin-Madison, 53706 Madison, WI |
| |
Abstract: | Thin, coherently strained, films of SiGe were deposited on Si(001) in the Stranski-Krastanow (SK) growth mode to form small,
faceted, dislocation-free-three-dimensional (3D) islands. The number density of these islands was determined as functions
of SiGe alloy composition, growth rate, and substrate temperature during growth. From these experiments, the classical model
of 3D island nucleation and growth yields an approximate activation energy for diffusion of Ge dimers on a Ge covered Si(001)
surface of 0.70 eV. The dependence of the 3D-island number density on growth rate cannot be understood without modifying the
classical model to account for the wetting layer present in SK systems. Heteroepitaxial strain is not included in the classical
model of island nucleation and growth. A simple linear elastic model that fits the data is developed that predicts the island
number density is proportional to the inverse square of the Ge mole fraction in the alloy plus a constant. |
| |
Keywords: | Heteroepitaxial strain SiGe Stranski-Krastanow (SK) three-dimensional (3D) islands |
本文献已被 SpringerLink 等数据库收录! |
|