Optical semiconductor element

An optical semiconductor element, comprising:

• a substrate;
• a semiconductor stacked body including an optical layer that generates or absorbs light, a first semiconductor layer arranged on a side opposite to the substrate with respect to the optical layer, and a second semiconductor layer arranged on a side of the substrate with respect to the optical layer, the optical layer and the first semiconductor layer forming a mesa portion formed on the second semiconductor layer and the second semiconductor layer including an outer portion located outside the mesa portion;
• a first electrode formed on the mesa portion and electrically connected to the first semiconductor layer;
• a first insulating layer formed on the first electrode;
• a second electrode including a first portion electrically connected to the second semiconductor layer at the outer portion, a second portion arranged on the first insulating layer so as to overlap the first electrode in a thickness direction of the substrate, and a third portion electrically connected to the first portion and the second portion;
• and
• a second insulating layer formed on the second electrode,
• wherein a first opening for exposing the first electrode is formed in the first insulating layer,
• a second opening for exposing the second portion of the second electrode is formed in the second insulating layer,
• at least a part of an upper surface of the first electrode is located nearer to the substrate than an upper surface of the second electrode,
• a third opening connected to the first opening is formed in a region of the second insulating layer on the first insulating layer,
• the third opening overlaps the first opening when viewed in a plan view of the optical semiconductor element, and
• when viewed in the plan view of the optical semiconductor element, the third portion extends along a first direction from the first portion toward the second portion, and a width of the third portion in a second direction perpendicular to the first direction is smaller than a width of the second portion in the second direction.