Fabricating method of optical semiconductor device

A method for fabricating a semiconductor laser on a circular semiconductor substrate, comprising parabolically changing an oscillation wavelength of said semiconductor laser from a center portion of said circular semiconductor substrate toward an outer periphery of said circular semiconductor substrate.

A method for fabricating a semiconductor optical modulator of an electro-absorption type, on a circular semiconductor substrate, comprising parabolically changing a band gap wavelength of an optical absorption layer of said semiconductor optical modulator from a center portion of said circular semiconductor substrate toward an outer periphery of said circular semiconductor substrate.

A method for fabricating a semiconductor optical integrated device having a distributed feedback laser diode monolithically integrated with a semiconductor optical modulator of an electro-absorption type or a distributed Bragg reflector laser diode monolithically integrated with a semiconductor optical modulator of an electro-absorption type, on a circular semiconductor substrate, comprising parabolically changing a band gap wavelength of an optical absorption layer of said semiconductor optical modulator and an oscillation wavelength of said distributed feedback laser diode or said distributed Bragg reflector laser diode from a center portion of said circular semiconductor substrate toward an outer periphery of said circular semiconductor substrate.

A method for fabricating an optical semiconductor device on a circular semiconductor substrate:

• comprising growing a semiconductor layer constituting said optical semiconductor device by metal-organic vapor phase epitaxy;
• while controlling a temperature distribution of said semiconductor substrate such that the band gap wavelength of the epitaxially grown layer is parabolically changed in a surface of said semiconductor substrate from a center portion of said semiconductor substrate toward an outer periphery thereof.

A method for fabricating an optical semiconductor device on a circular semiconductor substrate, comprising growing a semiconductor layer constituting said optical semiconductor device by selective metal-organic vapor phase epitaxy using a dielectric film as a growth blocking mask and changing a width of said growth blocking mask such that the band gap wavelength of the epitaxially grown layer is parabolically changed in a surface of said semiconductor substrate from a center portion of said semiconductor substrate toward an outer periphery thereof.

A method for fabricating an optical semiconductor device on a circular semiconductor substrate, comprising of growing a semiconductor layer constituting said optical semiconductor device by selective metal-organic vapor phase epitaxy using a dielectric film as a growth blocking mask while a width of an opening portion of said growth blocking mask is controlled such that the band gap wavelength of the epitaxially grown layer is parabolically changed in a surface of said semiconductor substrate from a center portion of said semiconductor substrate toward an outer periphery thereof.