Semiconductor optical device and a method of fabricating the same

Abstract

In order to provide excellent device characteristics and enhance fabrication yield and run-to-run reproducibility in a buried device structure using a low mesa on a p-type substrate, a cross sectional configuration before growth of a contact layer of a device, i.e., after growth of an over-cladding layer is flattened so as not to cause a problem in crystal quality of the contact layer. A mesa-stripe stacked body including at least a p-type cladding layer (), an active layer () and an n-type cladding layer () is formed on a p-type semiconductor substrate (), a current-blocking layer () is buried in both sides of the stacked body, and an n-type over-cladding layer () and an n-type contact layer () are disposed on the current-blocking layer () and the stacked body. The n-type over-cladding layer () is made of a semiconductor crystal having a property for flattening a concavo-convex shape of upper surfaces of the current-blocking layer () and the stacked body.