Abstract
We provide an overview of a novel self-assembly process that occurrs during GeSi/Si(001) strain-layer heteroepitaxy under conditions of limited adatom mobility. Suppression of copious surface diffusion leads to limited three-dimensional roughening in the form of pits that partially consume a thick, metastable wetting layer. The material ejected from the pits accumulates alongside, eventually forming a symmetric quantum dot molecule consisting of four islands bound to a {105}-faceted pit. These structures, which are of interest in nanologic applications, appear to arise from an intrinsic strainrelief mechanism in a relatively narrow regime of deposition conditions. An additional degree of morphological control is obtained by annealing films containing pits, before they evolve to full quantum dot molecules. Annealing promotes a one-dimensional growth instability leading to the formation of highly anisotropic grooves, bounded by long, wire-like islands. Finally, we show that patterns created in the Si substrate using a focused ion beam can control the location of quantum dot molecules, which is an additional critical step towards being able to use these structures for computing.
Original language | English (US) |
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Article number | KK4.3 |
Pages (from-to) | 1-11 |
Number of pages | 11 |
Journal | Materials Research Society Symposium Proceedings |
Volume | 849 |
State | Published - 2005 |
Event | 2004 MRS Fall Meeting - Boston, MA, United States Duration: Nov 29 2004 → Dec 2 2004 |
All Science Journal Classification (ASJC) codes
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering