Seminars Archive

Formation of low-dimensional semiconductor nanostructures on corrugated surfaces

Abstract
Nonplanar epitaxy on V-grooves is a convenient technique for semiconductor quantum wire (QWR) fabrication. QWR formation relies on the development of self-limiting profiles during growth. I will present an overview of the self-ordering phenomena observed in nonplanar Organometallic Chemical Vapor Deposition of QWRs, and introduce an analytical model that explains quantitatively this self-limiting growth. Self-ordering results from an equilibrium between the effects of growth rate anisotropy on the different planes composing the groove (that tend to sharpen it) and of adatom migration towards the bottom, due to curvature-related chemical potential differences (that tend to broaden it). During ternary growth, entropy of mixing effects add to the curvature-related ones, influencing the self-limiting shape. Predictions of this model are used to design novel low-dimensionality confined structures, such as vertical quantum wells, QWR superlattices and vertical arrays of quantum dots on inverted pyramids. Possible future directions towards the understanding of these self-ordering phenomena will be highlighted.