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) in situ 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 - 3·10⁷ cm^-2 for a layer thickness of ~6 μm. For comparison, the seed layer had a dislocation density of ~1·10⁹ cm^-2. 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.

Date Published: 17 May 2010
PDF: 9 pages
Proc. SPIE 7719, Silicon Photonics and Photonic Integrated Circuits II, 77190Q (17 May 2010); doi: 10.1117/12.858122

Published in SPIE Proceedings Vol. 7719:
Silicon Photonics and Photonic Integrated Circuits II
Giancarlo Cesare Righini, Editor(s)