Optical semiconductor device and method of fabricating the same

摘要

This invention provides an optical semiconductor device including a semiconductor substrate having a mesa stripe in which at least an optical waveguide layer is formed, a major surface of the semiconductor substrate being a crystal plane, a semiconductor buried layer formed on the two side surfaces of the mesa stripe, and a stripe cladding layer formed on the mesa stripe region and the semiconductor buried layer and having a shape whose section is substantially trapezoidal and whose side surfaces are crystal planes.