Morphological Evolution and Composition of Self-Assembled Ge/Si(100) Quantum Dots
Abstract
In this talk, we will first investigate the shape evolution of Ge/Si(100) islands as a function of size and then study the island composition at various growth temperatures. Atomic force microscope images were analyzed to map accurately the facet evolution of the Ge islands grown by molecular beam epitaxy at 400°C. A rich array of facets and island morphologies were observed in addition to the commonly observed huts, domes, and dislocated domes. We performed a statistical analysis of the electron energy loss spectroscopy data of the observed morphologies to determine their composition for growth temperatures between 400 and 700°C. Average Ge concentration in the islands is found to decrease dramatically as the growth temperature increases. In addition, an examination of the Ge/Si interface reveals an increasing diffusivity with growth temperature. The physics underlying these intriguing results will be discussed.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2002
- Bibcode:
- 2002APS..MARQ23012D