Semiconductor laser having protruding portion

[0099] An example of forming a p-side protruding portion on a p-type semiconductor layer in this embodiment will be described. FIG. 1 is a schematic view showing the semiconductor laser device of this embodiment. FIG. 1B is a sectional view taken along lines XX′ in FIG. 1A. FIG. 1C is a sectional view taken along lines YY′ in FIG. 1A. The semiconductor laser device has an n-type semiconductor layer 102, an active layer 104 and a p-type semiconductor layer 103 stacked on a substrate 101, with a ridge B having stripe shape formed by etching a part of the p-type semiconductor layer. A first insulating film 109 is formed to extend from the side face of the ridge B onto the surface of the p-type semiconductor layer 103 on both sides of the ridge. A p-side ohmic electrode 105 is formed to extend from the surface of the ridge B onto the first insulating film 109. A p-side pad electrode 106 is formed on the p-side ohmic electrode 105. Portions of the surfaces of the p electrodes 105 and 106 ar

[0111] This embodiment is an example of forming the n-side protruding portion A on the n-type semiconductor layer. FIGS. 2A through 2C schematically show the semiconductor laser device according to this embodiment. FIG. 2B is a sectional view taken along lines XX′ of FIG. 2A, and FIG. 2C is a sectional view taken along lines YY′ of FIG. 2A. This embodiment employs an insulating substrate 201 and, when the p electrode and the n electrode are formed on the same side of the substrate. Since the n-type semiconductor layer 12 is exposed by etching, the p electrode (p-side pad electrode) 206 and the n electrode (n-side pad electrode) 208 are different in the surface height as shown in FIG. 2B. As a result, a space is formed opening wide above the n electrode when forming the end face protective film as shown in FIG. 21B, thereby making it easier for the end face protective film to deposit on the n electrode. In this embodiment, in contrast, since the n-side protruding portion A is formed so

[0147] This embodiment is an example where both the p-side protruding portion and the n-side protruding portion are formed. FIGS. 3A through 3C are schematic diagrams showing a form of the semiconductor laser device obtained according to the method of the present invention. FIG. 3B is a sectional view taken along lines XX′ of FIG. 3A, and FIG. 3B is a sectional view taken along lines YY′ of FIG. 3A. The protruding portions of p side and n side are provided as shown in FIG. 3. By providing the protruding portions of p side and n side, it is made possible to suppress the component of the end face protective film from depositing on the p electrode and the n electrode.

(P-Side Protruding Portion and N-Side Protruding Portion)

[0148] In order to suppress the component of the end face protective film from depositing on the electrodes, it is preferable to provide the protruding portions on both p side and n side as in this embodiment. If the protruding portion is to be provided on only one s