Optical semiconductor device having ridge structure formed on active layer containing P-type region and its manufacture method

摘要

A p-type cladding layer (3) of p-type semiconductor is formed over a substrate. An active layer (5) including a p-type semiconductor region is disposed over the p-type cladding layer. A buffer layer (10) of non-doped semiconductor is disposed over the active layer. A ridge-shaped n-type cladding layer (11) of n-type semiconductor is disposed over a partial surface of the buffer layer. The buffer layer on both sides of the ridge-shaped n-type cladding layer is thinner than the buffer layer just under the ridge-shaped n-type cladding layer.