Patent ID: 8637337

Claim:
A method for producing an integrated optical device, comprising the steps of: preparing a substrate including first and second regions arranged in a predetermined direction; growing, on the first and second regions of the substrate, a first stacked semiconductor layer including a first optical waveguiding layer, first and second cladding layers positioned on the first optical waveguiding layer, and a first etch-stop layer positioned between the first and second cladding layers, the first etch-stop layer having a composition different from compositions of the first and second cladding layers; etching the first stacked semiconductor layer through a first etching mask formed on the first region until the first optical waveguiding layer is exposed; selectively growing, on the second region through the first etching mask, a second stacked semiconductor layer including a second optical waveguiding layer, third and fourth cladding layers positioned on the second optical waveguiding layer, and a second etch-stop layer positioned between the third and fourth cladding layers, the second etch-stop layer having a composition different from compositions of the third and fourth cladding layers; and forming a ridge structure by etching the second and fourth cladding layers through a second etching mask formed on the first and second stacked semiconductor layers, the second etching mask longitudinally extending in the predetermined direction, wherein the step of etching the first stacked semiconductor layer includes a step of forming a first overhang between the first and second cladding layers by selectively etching the first etch-stop layer by wet etching with an etchant having a higher etching rate for the first etch-stop layer than for the first and second cladding layers, the first overhang being constituted by the second cladding layer.