LASER-STIMULATED SELECTIVE-AREA GROWTH OF QUANTUM DOTS

We report on the selective area growth of InAs quantum dots on GaAs by ultraviolet (UV) laser stimulated or,organometallic vapor phase epita xy. At the low substrate temperature of 435 degrees C, exposure to a 2 48.2 nm continuous wave laser beam enhances the InAs growth rate by ap proximately 30%, causing the transition from two-dimensional (2D) to 3 D growth mode to occur in the laser stimulated region only. Photolumin escence spectra from the UV laser stimulated growth region show both w etting layer and quantum dot luminescence, whereas only the wetting la yer peak is present in the spectra from the dark grown regions. A phot oluminescence map shows good spatial agreement between the region exhi biting quantum dot luminescence and the UV stimulated spot size. Since no quantum dot peak shifts are detected, but the luminescence intensi ty increases towards the center of the region stimulated with the Gaus sian UV beam, we conclude that the island density rather than island s ize distribution is influenced by the UV intensity.