Method for the manufacture of optical semiconductor device

Claim 2

An optical semiconductor device manufacturing method comprising an ion implantation step of implanting ions into a compound semiconductor wafer through using an ion implantation mask and subsequently effecting an annealing step of activating atoms in the compound semiconductor wafer with an annealing mask film existing on the wafer, characterized in: that the ion implantation step and the annealing step are performed in succession after growing mono- or multi-layered compound semiconductor layers defining the ion implantation mask and defining the annealing mask film on the compound semiconductor wafer, and said implanting of ions into the compound semiconductor wafer being effected through the annealing mask film using the ion implantation mask.

Claim 3

An optical semiconductor device manufacturing method comprising an ion implantation step of implanting ions into a compound semiconductor wafer using an ion implantation mask and subsequently effecting an annealing step of activating atoms in the compound semiconductor wafer with an annealing mask film existing on the compound semiconductor wafer, characterized in: that the ion implantation step and the annealing step are performed in succession after growing mono- or multi-layered compound semiconductor layers defining the ion implantation mask and defining the ion implantation mask and defining the annealing mask film on the compound semiconductor wafer and then forming a metal thin film and an insulating film or forming at least the metal thin film on the ion implantation mask, and said implantation of ions into the compound semiconductor wafer being effected through the annealing mask film using the ion implantation mask and at least the metal thin film.

Claim 4

An optical semiconductor device manufacturing method comprising an ion implantation step of implanting ions into a compound semiconductor wafer using an ion implantation mask and subsequently effecting an annealing step of activating atoms in the compound semiconductor wafer with an annealing mask film existing on the compound semiconductor wafer, characterized in: that the ion implantation step and the annealing step are performed in succession after growing mono- or multi-layered compound semiconductor layers defining the ion implantation mask and defining the ion implantation mask and defining the annealing mask film on the compound semiconductor wafer and then forming a metal thin film and an insulating film or forming at least the metal thin film on the ion implantation mask, and said implantation of ions into the compound semiconductor wafer being effected through the annealing mask film using the ion implantation mask and at least the metal thin film.

Claim 5

An optical semiconductor device manufacturing method comprising an ion implantation step of implanting ions into a compound semiconductor wafer through an ion implantation mask and subsequently effecting an annealing step of activating atoms in the compound semiconductor wafer with an annealing mask film existing on the compound semiconductor wafer, the compound semiconductor wafer being composed of an optical waveguide formed by an optical waveguide layer and a plurality of clad layers smaller in energy gap than the optical waveguide layer and etched into a mesa-like form with an etching mask, a buried layer buried in the side of the mesa-like region, and at least one semiconductor layer grown on the buried layer and the optical waveguide, characterized in: that the ion implantation step and the annealing step are performed in succession after a step of forming, by crystal growth, at least one high carrier concentration semiconductor layer on the buried layer effective to diffuse an impurity dopant in the high carrier concentration semiconductor layer into the buried layer so that the high carrier concentration semiconductor layer extends down to the top of the optical waveguide and after a step of growing mono- or multi -layered compound semiconductor layers defining the ion implantation mask and defining the annealing mask film on the compound semiconductor wafer, and then forming a thin metal film and an insulating film or forming at least the thin metal film on the ion implantation mask.

Claim 6

An optical semiconductor device manufacturing method comprising an ion implantation step of implanting ions into a compound semiconductor wafer through an ion implantation mask and subsequently effecting an annealing step of activating atoms in the compound semiconductor wafer with an annealing mask film existing on the compound semiconductor wafer, the compound semiconductor wafer being composed of an optical waveguide formed by an optical waveguide layer and a plurality of clad layers smaller in energy gap than the optical waveguide layer and etched into a mesa-like form with an etching mask, a buried layer buried in the side of the mesa-like region, and at least one semiconductor layer grown on the buried layer and the optical waveguide, characterized in: that the ion implantation step and the annealing step are performed in succession after a step of forming, by crystal growth, at least one high carrier concentration semiconductor layer on the buried layer effective to diffuse an impurity dopant in the high carrier concentration semiconductor layer into the buried layer so that the high carrier concentration semiconductor layer extends down to the top of the optical waveguide and after a step of growing mono- or multi -layered compound semiconductor layers defining the ion implantation mask and defining the annealing mask film on the compound semiconductor wafer, and then forming a thin metal film and an insulating film or forming at least the thin metal film on the ion implantation mask.