Proceedings Article | 18 May 2010
Proc. SPIE. 7719, Silicon Photonics and Photonic Integrated Circuits II
KEYWORDS: Luminescence, Indium, Silicon, Atomic force microscopy, Photonics, Silicon photonics, Neodymium, Semiconducting wafers, Vapor phase epitaxy, Epitaxial lateral overgrowth
There is an intense interest on integration of III-V materials on silicon and silicon-on-insulator for realisation of optical
interconnects, optical networking, imaging and disposable photonics for medical applications. Advances in photonic
materials, structures and technologies are the main ingredients of this pursuit. We investigate nano epitaxial lateral
overgrowth (NELOG) of InP material from the nano openings on a seed layer on the silicon wafer, by hydride vapour
phase epitaxy (HVPE). The grown layers were analysed by cathodoluminescence (CL) <i>in situ</i> a scanning electron
microscope, time-resolved photoluminescence (TR-PL), and atomic force microscope (AFM). The quality of the layers
depends on the growth parameters such as the V/III ratio, growth temperature, and layer thickness. CL measurements
reveal that the dislocation density can be as low as 2 - 3·10<sup>7</sup> cm<sup>-2</sup> for a layer thickness of ~6 μm. For comparison, the
seed layer had a dislocation density of ~1·10<sup>9</sup> cm<sup>-2</sup>. Since the dislocation density estimated on theoretical grounds from
TRPL measurements is of the same order of magnitude both for NELOG InP on Si and on InP substrate, the dislocation
generation appears to be process related or coalescence related. Pertinent issues for improving the quality of the grown
InP on silicon are avoiding damage in the openings due to plasma etching, pattern design to facilitate coalescence with
minimum defects and choice of mask material compatible with InP to reduce thermal mismatch.
