US Patent 7123639 Semiconductor optical device and method of making the same

A semiconductor optical device 100 has an n-type semiconductor layer 2, an active layer 3, and a p-type semiconductor portion 4 provided in order on a principal surface 1a of a substrate 1. The p-type semiconductor portion 4 has a ridge portion 40 and a base portion 42, and a contact layer 5 is formed on the ridge portion 40. A first portion 60 of an insulating layer 6 extends along a plane intersecting with the principal surface 1a of the substrate 1, on a side face 4b of the ridge portion 40 and on a side face 5b of the contact layer 5. An end 6a of the first portion 60 is higher than an edge 5c of the side face 5b of the contact layer 5.