In-situ monitoring of arsenic-phosphorus exchange in MOVPE growth of InGaAs/InP quantum wells by kinetic ellipsometry

In InGaAs/InP heterostructures, interdiffusion of arsenic and phosphorus at the hetero interfaces (As-P exchange) during epitaxial growth degrades the interface abruptness. This is a significant problem when a very thin InGaAs/InP quantum well is required. In this paper, a spectroscopic and kinetic ellipsometry is used to monitor the As-P exchange in-situ in metal-organic vapor phase epitaxy (MOVPE) with TBAs and TBP as group V precursors. As a result, it is found that the monitoring of As-P exchange is possible by kinetic ellipsometry and that useful information to improve gas switching sequence is acquired from such observation. An InGaAs/InP quantum well grown by making use of such information has exhibited the best photoluminescence characteristics