Method for fabricating fiducials for passive alignment of opto-electronic devices

A method for fabricating a buried heterostructure edge-emitting laser with a fiducial from a multi-layered structure comprising a substrate and an etch-stop layer, said method comprising the steps of:

• (1) creating a multi-layered structure on a substrate;
• (2) growing a first quaternary layer on said multi-layered structure, said quaternary layer being an etch-stop layer;
• (3) etching through said etch-stop layer, cladding layer, first quaternary layer, and buffer layer to form an active mesa and a fiducial, said fiducial comprising at least one surface positioned in a known spatial relation relative to said mesa;
• (4) disposing a photoresist over said fiducial;
• (5) further etching said active mesa;
• and
• (6) removing said etch mask and said photoresist to expose said fiducial and define etched cavities surrounding said active mesa;
• (7) disposing a first blocking layer in the etched cavities defining said active mesa and a second blocking layer over said fiducial;
• (8) disposing a burying layer over said active mesa, said blocking layer, and said fiducial;
• and
• (9) selectively etching said burying layer and said second blocking layer to expose said fiducial.