Semiconductor optical device
A semiconductor optical device includes: a buried layer having a side surface, an upper surface, and an intermediate region; an insulating film on the upper surface of the buried layer; and an electrode including a mesa electrode, a pad electrode, and a lead-out electrode. The upper surface of the buried layer has an outer edge including a first edge extending along the first direction and a second edge extending along a second direction. The intermediate region includes an upright surface that stands straight between the side surface and the first edge, and a slope surface that slopes more gently than the upright surface and extends downward from the second edge. The lead-out electrode includes a portion on the insulating film and connected to the pad electrode, another portion on the intermediate region and through the slope surface, and another portion connected to the mesa electrode.
1 . A semiconductor optical device comprising:
a mesa-stripe structure extending in a first direction;
a buried layer configured to bury both sides of the mesa-stripe structure;
an insulating film on an upper surface of the buried layer and not on a top surface of the mesa-stripe structure,
wherein the insulating film includes a cut-out section, in a plan view, depressed in a second direction that is perpendicular to the first direction; and
an electrode including:
a mesa electrode on the top surface of the mesa-stripe structure,
a pad electrode at least partially on the insulating film, and
a lead-out electrode between the mesa electrode and the pad electrode,
wherein the lead-out electrode is inside and outside the cut-out section.
2 . The semiconductor optical device according to claim 1 , wherein the cut-out section has a length, in the second direction, that is less than or equal to half of a length of the lead-out electrode.
3 . The semiconductor optical device according to claim 1 , wherein the cut-out section has a first width and a second width in the first direction,
wherein the first width is located farther from the mesa-stripe structure than the second width, and
wherein the first width is less than the second width.
4 . The semiconductor optical device according to claim 1 , wherein the cut-out section has a width, in the first direction, that is uniform along an entire length of the cut-out section.
5 . The semiconductor optical device according to claim 1 , wherein the lead-out electrode has a width, in the first direction, that is less than a width of the pad electrode along the first direction.
6 . The semiconductor optical device according to claim 1 , wherein a part of the pad electrode is inside the cut-out section.
7 . The semiconductor optical device according to claim 1 , wherein the cut-out section has a depth that extends to the upper surface of the buried layer.
8 . A semiconductor optical device comprising:
a mesa-stripe structure extending in a first direction;
a buried layer configured to bury both sides of the mesa-stripe structure;
an insulating film on the buried layer and not on the mesa-stripe structure,
wherein the insulating film includes an opening, in a plan view, depressed in a second direction perpendicular to the first direction; and
an electrode including:
a mesa electrode on the mesa-stripe structure,
a pad electrode on the insulating film, and
a lead-out electrode between the mesa electrode and the pad electrode,
wherein the lead-out electrode is inside and outside the opening.
9 . The semiconductor optical device according to claim 8 , wherein the opening has a length, in the second direction, that is less than or equal to one fourth of a length of the lead-out electrode.
10 . The semiconductor optical device according to claim 8 , wherein the opening has a non-uniform width in the first direction.
11 . The semiconductor optical device according to claim 8 , wherein the opening has a width, in the first direction, that is uniform along an entire length of the opening.
12 . The semiconductor optical device according to claim 8 , wherein the lead-out electrode has a width, in the first direction, that is less than a width of the pad electrode along the first direction.
13 . The semiconductor optical device according to claim 8 , wherein the opening has a length, in the second direction, that is greater than a length of the lead-out electrode.
14 . The semiconductor optical device according to claim 8 , wherein the opening has a depth that extends to an upper surface of the buried layer.
15 . A semiconductor optical device comprising:
a mesa-stripe structure extending in a first direction;
a buried layer configured to bury both sides of the mesa-stripe structure;
an insulating film on the buried layer and including:
a mesa opening surrounding the mesa-stripe structure, and
an extraction opening extending in a second direction from the mesa opening,
wherein the second direction is perpendicular to the first direction; and
an electrode including:
a mesa electrode inside the mesa opening,
a pad electrode, and
a lead-out electrode inside the extraction opening and between the mesa electrode and the pad electrode.
16 . The semiconductor optical device according to claim 15 , wherein the extraction opening has a length, in the second direction, that is less than a length of the lead-out electrode.
17 . The semiconductor optical device according to claim 15 , wherein the extraction opening has a first width and a second width in the first direction,
wherein the first width is located farther from the mesa-stripe structure than the second width, and
wherein the first width is less than the second width.
18 . The semiconductor optical device according to claim 15 , wherein the extraction opening has a width, in the first direction, that is uniform along an entire length of the extraction opening.
19 . The semiconductor optical device according to claim 15 , wherein the lead-out electrode has a width, in the first direction, that is less than a width of the pad electrode along the first direction.
20 . The semiconductor optical device according to claim 15 , wherein a part of the pad electrode is inside the extraction opening, and another part of the pad electrode is on the insulating film.
21 . The semiconductor optical device according to claim 15 , wherein the extraction opening has a depth that extends to an upper surface of the buried layer.