Selective epitaxy of semiconductor nanopyramids for nanophotonics

Abstract

We present a detailed study of the parameters which affect the geometrical perfection of nanopyramids used for the site-selected nucleation of quantum dots. Through an understanding of crystal facet formation, we demonstrate that undesirable high index planes can be suppressed using carefully optimized lithography together with properly orientated source fluxes in the growth reactor. High quality InP nanopyramids are reported with individual InAs/InP quantum dots positioned with high precision. This represents an important milestone for the fabrication of complex quantum dot based nanophotonic devices.

Influence of electron-acoustic phonon scattering on off-resonant cavity feeding within a strongly coupled quantum-dot cavity system

“…The single QD-cavity system is realized by nucleating one InAs QD at the apex of a InP pyramid (see Fig. 4) grown using selective-area epitaxy 49 . Dot formation on these InP pyramidal nanotemplates proceeds via the Stranski-Krastanow growth mode 50 similar to growth on planar substrates although some subtleties of the strain distribution will differ due to the proximity of the {110} planes that make up the sidewalls of the InP pyramid.…”

Mesa-top quantum dot single photon emitter arrays: Growth, optical characteristics, and the simulated optical response of integrated dielectric nanoantenna-waveguide systems

“…The growth is typically done using all gaseous molecular sources such as in gas source MBE or metal organic chemical vapor deposition (MOCVD) as the slow dissociative reaction kinetics and fast desorption kinetics of the relevant molecular species on the oxide enables selective growth in the holes. The lateral size and depth of the holes has been exploited for selective placement of quantum dots, including single [51][52][53] . However, such growth, being spontaneous, is sensitive to the fluctuations in the size and shape of the holes and does not allow the needed control on the shape and size of QDs formed.…”

Positioned growth of InP nanowires

“…This explains why for the VLS case the wire does not fill the opening in the SiO 2 mask, but for the catalyst-free case it does. Due to the limited lateral size of the opening in which growth occurs faceting is observed 16 . The result is a structure that grows in the <111>A direction, but in this case with a poorly defined tip shape consisting of many step edges where incorporation preferentially occurs, and well-defined faceted sidewalls with long incorporation lengths.…”