Method for producing an optical semiconductor device having a carrier injection path or an electric-field applying path

摘要

An optical semiconductor device includes a plurality of electrodes formed on a common side of a substrate. On the substrate, a first type conductivity layer, a first main layer such as an active layer, which has any one of an undoped type, a first type conductivity and a second type conductivity, and a second type conductivity layer are formed in this order. The layers down to at least the second type conductivity layer are removed to form a ridge and at least one contact groove, which reaches the first type conductivity layer, is formed, such that surfaces having different surface indices from a surface index of the substrate are exposed at the ridge and the contact groove. A regrowth is performed on the exposed surfaces using an amphi-conductivity impurity as a dopant, such that a first portion having a first type conductivity is grown on the contact groove and a second portion having a second type conductivity is grown on the ridge. At least one transverse pn reverse junction portion is also formed during the regrowth performing step. The first type conductivity layer and the first portion act as a current injection path or first means for applying an electric field to the first main layer, and the second type conductivity layer and the second portion act as another current injection path or second means for applying an electric field to the first main layer which cooperates with the first means.