Advances in the growth and characterization of Ge quantum dots and islands
- PDF / 1,822,716 Bytes
- 16 Pages / 612 x 792 pts (letter) Page_size
- 31 Downloads / 201 Views
Review
Advances in the growth and characterization of Ge quantum dots and islands J-M. Baribeaua) Institute for Microstructural Sciences, National Research Council Canada, Ottawa, Ontario, K1A 0R6, Canada
N.L. Rowell Institute for National Measurements Standards, National Research Council Canada, Ottawa, Ontario, K1A 0R6, Canada
D.J. Lockwood Institute for Microstructural Sciences, National Research Council Canada, Ottawa, Ontario, K1A 0R6, Canada (Received 8 June 2005; accepted 18 August 2005)
We review recent advances in the growth of Si1−xGex islands and Ge dots on (001) Si. We first discuss the evolution of the island morphology with Si1−xGex coverage and the effect of growth parameters or post-growth annealing on the shape of the islands and dots. We outline some of the structural and optical properties of Si1−xGex islands and assess progress in the determination of their composition and strain distribution. Finally, we discuss various approaches currently being investigated to engineer Si1−xGex quantum dots and in particular to control their size, density, and spatial distribution. For example, we show how C pre-deposition on Si (001) can influence the nucleation and growth of Ge islands.
I. INTRODUCTION
The growth and properties of semiconductor threedimensional (3D) islands and quantum dots have been studied extensively in the last decade. These novel nanostructures offer interesting prospects for the development of new electronic or optoelectronic devices. Accurate control of the size, shape, position, and density is, however, crucial for the exploitation of these nanostructures in quantum devices such as qbits or single photon emitters. Si1−xGex on Si is one of the best-studied systems exhibiting self-organized nanostructures in semiconductor heteroepitaxy. When deposited on (001) Si, Ge, and Si1−xGex alloys can undergo a transition from planar twodimensional (2D) growth to a 3D island structure1,2 when
a)
Address all correspondence to this author. e-mail: [email protected] This paper was selected as the Outstanding Meeting Paper for the 2004 MRS Fall Meeting Symposium F Proceedings, Vol. 832. DOI: 10.1557/JMR.2005.0405 3278
J. Mater. Res., Vol. 20, No. 12, Dec 2005
the development of a 3D morphology is energetically more favorable than the generation of dislocations.3,4 Considerable work has been done on the growth and characterization of Si1−xGex islands and Ge dots, and important results have been reported in several reviews.5–9 Here we briefly outline progress in the growth and characterization of Si1−xGex islands and Ge dots on (001) Si. In particular, we discuss the evolution of the island morphology with Si1−xGex coverage, look at the effect of the growth parameters or post-growth treatments on the shape of the islands, review recent developments in the determination of the composition and strain distribution of individual Si1−xGex islands, discuss the optical properties of dots and islands stressing the importance of quantum confinement, and finally, examine various appro
Data Loading...
