Selective nucleation and controlled growth: quantum dots
on metal, insulator and semiconductor surfaces
J. A. Venables, P.A. Bennett, H. Brune, J. Drucker & J.H. Harding,
submitted to Phil. Trans. Roy. Soc. London series A, May 2002.
Nucleation and growth models are well developed for nucleation on homogeneous substrates,
and can typically be described in terms of three energy parameters. Nucleation on
substrates containing point defect traps has been investigated, at the cost of
introducing more energy parameters. This paper outlines the quantitative description
of such growth models, using rate and rate-diffusion equations, in terms of energies
for individual surface processes, with examples taken from metal-metal, metal-insulator
and semiconductor growth. The challenge to modelling is to describe the large range
of length and time scales in thin film fabrication and degradation, without relying
on too many (unknown) material parameters, which often occur in combination. Separating
them into elementary processes often proves to be a challenge. One typically requires
selective nucleation using patterned substrates, in combination with controlled,
self-organized, growth for reliable nanotechnology. Reconstructed semiconductor
surfaces offer both a further challenge to modelling and an opportunity for future
technology; these paradoxes are discussed as space permits.
Latest version of this document: 24th May 2002.