Dynamics of Epitaxy on the Nano-sized Semiconductor Surfaces
Abstract
Semiconductor self assembled quantum dots (QDs) have emerged as one of the simplest subjects for exploring and exploiting the physics and device applications of charge carriers and excitons in the three dimensional confinement regime. Nanoscale-sized surface in the form of mesa or ridges on patterned substrates offer opportunities not only for creating large densities of QDs with great homogeneity but also for novel growth-control engineering. This project aims at a fundamental understanding of the size-dependent crystal growth phenomena during the formation of QDs on the surfaces of Si stripe and mesa structures. Employing variable-temperature scanning probe microscope (VT-SPM) on the patterned substrates, we plan to observe in situ the atomistic chemical vapor deposition (CVD) growth mechanism of the QDs on the top terraces as well as on the sidewalls of pre-patterned structures. The key objective in this proposed research is to fabricate patterned structures with well-defined side walls. Specifically, we plan to fabricate patterned mesa and stripe structure with the flat (111) sidewalls on the Si(100) substrates by means of lithography and anisotropic wet chemical etch. When the patterned surface consists only of low-index surfaces with well-characterized structures, its growth behavior become more predictable and tunable. We will then perform epitaxy on the patterned surfaces and observe their evolution in atomic structure and in surface morphology on both the (100) top terraces and (111) sidewalls and QD formation in situ, in real time and in real space using VT-SPM. The fundamental understanding of the results could provide useful physical guidelines in preparing QDs for many researchers and contribute to device application development in a long-term base.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 05, 2006
- Accession Number
- ADA466533
Entities
People
- Deng-sung Lin
Organizations
- National Chiao Tung University