Semiconductor device, semiconductor laser, and method of producing a semiconductor device

A semiconductor device, comprising:

• a first semiconductor layer having a first conductivity type, wherein a first surface of the first semiconductor layer forms a stripe-shaped ridge;
• a second semiconductor layer having a second conductivity type;
• an active layer between the first semiconductor layer and the second semiconductor layer, wherein the active layer is in direct contact with a second surface of the first semiconductor layer opposite to the first surface of the first semiconductor layer;
• a transparent conductive layer that comprises a transparent conductive material, wherein
• the transparent conductive layer contacts the first semiconductor layer on the stripe-shaped ridge, a second width is not less than 0.99 and not more than 1.0 times a first width,
• a third width is not less than 0.96 and not more than 1.0 times the second width,
• the transparent conductive layer has a uniform thickness within a range of not less than 90% and not more than 110% of the third width,
• the first width is a width of a surface of the stripe-shaped ridge in a direction perpendicular to an extending direction of the stripe-shaped ridge,
• the second width is a width of a first surface of the transparent conductive layer on a side of the stripe-shaped ridge in the direction, and
• the third width is a width of a second surface of the transparent conductive layer opposite to the stripe-shaped ridge in the direction;
• and
• a pad electrode that comprises a conductive material, wherein
• the pad electrode comes into contact with the transparent conductive layer,
• the transparent conductive layer connects the first semiconductor layer and the pad electrode,
• the pad electrode includes an intermediate layer on a connection part between the pad electrode and the transparent conductive layer,
• constituent elements of the pad electrode and constituent elements of the transparent conductive layer are fused in the intermediate layer, and
• the intermediate layer has a structure having mixed crystals of indium, tin, oxygen, and titanium.