The deposition of InAs on GaAs proceeds first by two-dimensional (2D)
growth and above a 1.75-monolayer coverage by the formation of single-
crystal dots on a residual 2D wetting layer. By atomic force microscop
y measurements, we show that the first dots formed are in the quantum
size range (height 30 Angstrom half-base 120 Angstrom), that the dispe
rsion on their sizes is remarkably low (+/- 10%), and that they are lo
cated fairly regularly (interdot distance 600 Angstrom). Upon further
growth, density and shapes do not change but sizes increase up to doub
le values before coalescence occurs. Self-organized growth in strained
structures is then shown to be a simple and efficient way of building
regular quantum dots.