Microstructure analysis of epitaxially grown self-assembled Ge islands on nanometer-scale patterned SiO{sub 2}/Si substrates by high-resolution transmission electron microscopy
- Department of Nano Science and Engineering, Myongji University, Yongin, Gyeonggi-do 449-728 (Korea, Republic of)
The microstructure of epitaxially grown self-assembled Ge islands on patterned SiO{sub 2}/Si substrates was analyzed using high resolution transmission electron microscopy. The Ge islands were grown by molecular beam epitaxy on hexagonally ordered Si hole arrays with {approx}25 nm diameter and {approx}40 nm center-to-center distance, which are covered by 30 nm thick SiO{sub 2} mask layer patterned using self-assembled diblock copolymers. The Ge islands nucleate preferentially at the edge of overetched Si surface, and subsequently grow selectively on Si surface as opposed to SiO{sub 2} surface with increasing coverage. The lattice planes of some Ge islands are tilted from those of Si substrates. This is believed to be the reason for the observed misalignment of moire fringes. The diameter of the Ge islands is identical to that of Si holes for large Ge coverage due to the selective growth behavior. These islands are found to have dislocations at the interface with the Si substrate. These results highlight the important microstructural issues and growth behavior of quantum dots on patterned substrates.
- OSTI ID:
- 21064454
- Journal Information:
- Journal of Applied Physics, Vol. 102, Issue 10; Other Information: DOI: 10.1063/1.2812610; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Defect reduction in epitaxial GaSb grown on nanopatterned GaAs substrates using full wafer block copolymer lithography
Evolution of surface roughness in epitaxial Si{sub 0.7}Ge{sub 0.3}(001) as a function of growth temperature (200{endash}600{degree}C) and Si(001) substrate miscut