Patent ID: 7378681

Claim:
A method for reducing surface recombination in an area next to a mesa in an optical semiconductor device, the method comprising the steps of: a) providing a semiconductor cladding material on a waveguide layer; b) forming the mesa on the semiconductor cladding material by selectively etching the semiconductor cladding material down to the waveguide layer forming exposed areas of the waveguide layer next to the mesa on either side thereof and of an upper cladding layer on sidewalls of the mesa; and c) growing a thin epitaxial layer of material with a larger bandgap than the waveguide material on the exposed areas in order to reduce carrier surface recombination within the waveguide material in the area; wherein step c) includes: growing a thin epitaxial layer of semiconductor material with a larger band gap than the waveguide layer over top and sidewalls of the mesa and the area next to the mesa; and removing the thin epitaxial layer from the top of the mesa to uncover the contact layer.