Yield Improvement by Wafer Mapping the Polarization Correction in InP/InGaAsP WDM Optical Power Monitors

摘要

We describe how a careful analysis of Photo-Luminescence, Mis-Match and Thicknesses in epitaxial layers that form the passive optical waveguide of a fully integrated Optical Power Monitor, can be used to eliminate yield losses from polarization dependant frequency shifts. The element which corrects polarization shifts, the compensator, is a prism like feature etched into a key epitaxial layer. Its shape can be adjusted for different dies according to the radial distributions found in the epitaxial layers from PL and X-ray mis-match maps. Yield losses from polarization dependant shifts are decreased from 90% to practically ～0%.