Semiconductor optical device and method for manufacturing the same

Abstract

A semiconductor optical device, for example, includes: a base intersecting a first direction; a first protrusion protruding from the base in the first direction, comprising a planar lightwave circuit including a core layer and a cladding surrounding the core layer; a second protrusion protruding from the base in the first direction and arranged with the first protrusion in a second direction intersecting the first direction, with a height from the base in the first direction being lower than that of the first protrusion; an optical semiconductor element mounted on an end face of the second protrusion in the first direction and optically connected to the core layer; and a mark provided on the second protrusion so as to be exposed on the end face and made of the same material as the core layer.

Description

Technical Field

[0001] The present invention relates to a semiconductor optical device and a method for manufacturing the semiconductor optical device. Background Art

[0002] Conventionally, a semiconductor optical device is known in which a planar lightwave circuit is formed on a silicon substrate and a laser element is mounted at a predetermined position on a heat sink (submount) that includes the silicon substrate and the planar lightwave circuit (Patent Document 1). In Patent Document 1, alignment marks are formed on the heat sink to position the heat sink and the laser element.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2007-264470 Summary of the Invention

[0006] -Problems to be solved by the invention-

[0007] In the past, alignment marks such as those described above were often formed by forming a metal layer on the surface of a heat sink and then removing the metal layer, leaving the alignment mark shape. In this case, if the positional accuracy of the alignment mark relative to the core layer of the planar lightwave circuit is low, the positioning accuracy of the laser element and the planar lightwave circuit will be reduced.

[0008] Therefore, one of the objects of the present invention is to provide a semiconductor optical device having an improved novel structure and a method for manufacturing the semiconductor optical device, for example, capable of further improving the positioning accuracy of an optical semiconductor element.

[0009] -Methods for solving the problem-

[0010] The semiconductor optical device of the present invention, for example, comprises: a base intersecting a first direction; a first protrusion protruding from the base in the first direction and having a planar lightwave circuit, the planar lightwave circuit having a core layer and a cladding surrounding the core layer; a second protrusion protruding from the base in the first direction, arranged together with the first protrusion in a second direction intersecting the first direction, and having a height from the base in the first direction lower than that of the first protrusion; an optical semiconductor element mounted on an end face of the second protrusion in the first direction and optically connected to the core layer; and a mark provided on the second protrusion so as to be exposed on the end face and made of the same material as the core layer.

[0011] Alternatively, in the semiconductor optical device, the height of the end of the core layer in the direction opposite to the first direction from the base in the first direction is the same as the height of the end of the mark in the direction opposite to the first direction from the base in the first direction.

[0012] The semiconductor optical device may include a first mark as the mark, the first mark being adjacent to an edge of the optical semiconductor element with a gap therebetween when viewed in a direction opposite to the first direction.

[0013] The semiconductor optical device may include two second marks as the marks, and the optical semiconductor element may be located between the two second marks when viewed in a direction opposite to the first direction.

[0014] In the semiconductor optical device, the optical semiconductor element may have a quadrilateral shape when viewed in the direction opposite to the first direction, and the semiconductor optical device may have a third mark, which is adjacent to the corner of the optical semiconductor element when viewed in the direction opposite to the first direction to serve as the mark.

[0015] The semiconductor optical device may include two second protrusions as the second protrusions, and the optical semiconductor element may include a first electrode provided on an end surface of the optical semiconductor element in a direction opposite to the first direction and located between the two second protrusions.

[0016] The semiconductor optical device may further include a conductor located between the two second protrusions and electrically connected to the first electrode.

[0017] In the semiconductor optical device, the conductor may be a conductive paste.

[0018] In the semiconductor optical device, a rough surface that contacts the conductive paste and has a larger surface roughness than other portions may be provided on the end surface of the base in the first direction at a position between the two second protrusions.

[0019] The semiconductor optical device may further include a second electrode provided at a position between the two second protrusions on the end surface of the base in the first direction and electrically connected to the conductor.

[0020] The semiconductor optical device may also include: a third protrusion, which protrudes from a position of the base between the two second protrusions toward the first direction, and the height from the base in the first direction is lower than the two second protrusions; and a third electrode, which is arranged on the end face of the third protrusion in the first direction and is electrically connected to the conductor.

[0021] In the semiconductor optical device, the two protrusions may be separated in the second direction, and a second protrusion located farther from the first protrusion among the two second protrusions may be integrated with the third protrusion.

[0022] The semiconductor optical device may also include: a fourth protrusion, which protrudes from the base toward the first direction on the opposite side of the third protrusion relative to the second protrusion integrated with the third protrusion, and the height from the base in the first direction is higher than the two second protrusions, and a fourth electrode electrically connected to the third electrode is provided on the end face of the fourth protrusion in the first direction.

[0023] The semiconductor optical device may also include: a wiring pattern, which is arranged over the end face of the third protrusion in the first direction, the end face of the second protrusion in the first direction integrated with the third protrusion, and the end face of the fourth protrusion in the first direction, and electrically connects the third electrode and the fourth electrode.

[0024] The semiconductor optical device may also include: a first inclined surface between the third protrusion and the second protrusion integrated with the third protrusion, which extends toward the first direction as it moves in the direction opposite to the second direction, and the wiring pattern has a portion extending along the first inclined surface.

[0025] The semiconductor optical device may further include a second inclined surface between the second protrusion integrated with the third protrusion and the fourth protrusion, the second inclined surface extending in the first direction as it moves in a direction opposite to the second direction, and the wiring pattern has a portion extending along the second inclined surface.

[0026] In the semiconductor optical device, the central axis of the core layer may be offset in a direction opposite to the first direction with respect to the central axis of the active layer of the optical semiconductor element.

[0027] In the semiconductor optical device, an end portion of the optical semiconductor element in the second direction may abut against an end surface of the first protrusion in a direction opposite to the second direction.

[0028] In the semiconductor optical device, an end surface of the first protrusion in the direction opposite to the second direction may be inclined toward the second direction as it moves toward the first direction, and may abut against an end portion of the optical semiconductor element in the second direction.

[0029] In the semiconductor optical device, a recessed portion recessed in a direction opposite to the first direction may be provided between the first protrusion and the second protrusion.

[0030] It is also possible that in the semiconductor optical device, the end face of the first protrusion in the direction opposite to the second direction has: a first face, which is arranged to be offset from the core layer to a third direction intersecting the first direction and the second direction, and abuts against the end of the optical semiconductor element in the second direction; and a second face, which is adjacent to the first face in the direction opposite to the third direction, and is inclined relative to the first face so that the core layer and the end of the optical semiconductor element in the second direction are exposed in the direction opposite to the second direction with a gap therebetween, and is directed toward the second direction as it moves toward the direction opposite to the third direction.

[0031] In the semiconductor optical device, a normal direction of the second surface and an optical axis direction of the core layer may intersect obliquely.

[0032] The semiconductor optical device may also include: a plurality of optical semiconductor elements as the optical semiconductor elements, each having a bottom surface placed on the second protrusion and an end surface in the second direction where the active layer is exposed, and the distance between the bottom surface and the active layer in the first direction is different; a plurality of second protrusions as the second protrusions, each having a different height from the base in the first direction, and respectively carrying different optical semiconductor elements; and a plurality of core layers as the core layers, each coupling light output by a different optical semiconductor element, the plurality of core layers in the first direction having the same distance from the base, and for a plurality of combinations of the second protrusion and the optical semiconductor element placed on the second protrusion, the distance from the base to the active layer in the first direction is the same, and the core layers arranged in the second direction with the optical semiconductor element couple light output by each of the optical semiconductor elements.

[0033] The manufacturing method of the semiconductor optical device of the present invention, for example, comprises: a process of forming a first layer by stacking along the first direction on a base intersecting with the first direction, the first layer including a portion that becomes a cladding layer of a planar lightwave circuit; a process of forming a second layer by stacking along the first direction on the first layer, the second layer including a portion that becomes a core layer of the planar lightwave circuit; a process of forming the core layer and a mark by selectively removing a stack of the second layer; a process of forming a third layer that becomes a portion of the cladding layer on a stack of the core layer and the mark formed on the first layer; a process of forming a first protrusion and a second protrusion by selectively removing a stack of the first layer, the core layer, the mark and the third layer, the first protrusion including at least the planar lightwave circuit and protruding from the base in the first direction, the second protrusion protruding from the base in the first direction at a height lower than the first protrusion with the mark exposed on the end face in the first direction; and a process of placing an optical semiconductor element on the second protrusion with the mark positioned.

[0034] -Effects of the Invention-

[0035] According to the present invention, for example, a semiconductor optical device having an improved novel structure and a method for manufacturing the semiconductor optical device can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is an illustrative and schematic perspective view of the semiconductor optical device according to the first embodiment.

[0037] Figure 2 It is an illustrative and schematic side view of the semiconductor optical device according to the first embodiment.

[0038] Figure 3 It is an illustrative and schematic top view of the semiconductor optical device according to the first embodiment.

[0039] Figure 4 yes Figure 2 An enlarged view of a portion of .

[0040] Figure 5 This is an illustrative and schematic plan view of a portion of the semiconductor optical device according to the first embodiment, with the light emitting element removed.

[0041] Figure 6 This is a flowchart showing an example of a method for manufacturing the semiconductor optical device according to the first embodiment.

[0042] Figure 7 The semiconductor optical device of the second embodiment Figure 4 An illustrative and schematic side view of the same.

[0043] Figure 8 It is an illustrative and schematic side view of a portion of the semiconductor optical device according to the third embodiment.

[0044] Figure 9 It is an illustrative and schematic side view of a semiconductor optical device according to a fourth embodiment.

[0045] Figure 10 It is an illustrative and schematic side view of a portion of a semiconductor optical device according to a fifth embodiment.

[0046] Figure 11 It is an illustrative and schematic top view of a semiconductor optical device according to a sixth embodiment.

[0047] Figure 12 It is an illustrative and schematic top view of a semiconductor optical device according to a seventh embodiment.

[0048] Figure 13 yes Figure 12 Sectional view XIII-XIII.

[0049] Figure 14 It is an illustrative and schematic top view of a portion of the semiconductor optical device according to the eighth embodiment.

[0050] Figure 15 It is an illustrative and schematic top view of a portion of the semiconductor optical device according to the ninth embodiment.

[0051] Figure 16 yes Figure 15 Sectional view XVI-XVI of FIG. DETAILED DESCRIPTION

[0052] The following discloses exemplary embodiments of the present invention. The structures of the embodiments shown below, as well as the functions and results (effects) brought about by these structures, are merely examples. The present invention can also be implemented using structures other than those disclosed in the following embodiments. In addition, according to the present invention, at least one of the various effects (including derived effects) obtained by the structures can be obtained.

[0053] The multiple embodiments shown below possess the same structure. Thus, according to the structure of each embodiment, the same action and effect based on the same structure can be obtained. In addition, the following same reference numerals are given to these same structures, and repeated description is sometimes omitted.

[0054] In this specification, ordinal numbers are given for the convenience of distinguishing parts, directions, etc., and do not indicate priority or order.

[0055] In each drawing, the X direction is indicated by an arrow X, the Y direction is indicated by an arrow Y, and the Z direction is indicated by an arrow Z. The X direction, the Y direction, and the Z direction intersect with each other and are orthogonal to each other.

[0056] [First embodiment]

[0057] Figure 1 is a perspective view of the semiconductor optical device 100A according to the first embodiment. Figure 2 is a side view of the semiconductor optical device 100A. Figure 3 It is a top view of the semiconductor optical device 100A.

[0058] The semiconductor optical device 100A includes a base 10 , a first protrusion 11 , two second protrusions 12 ( 12 - 1 and 12 - 2 ), a third protrusion 13 , a fourth protrusion 14 , and a light emitting element 20 .

[0059] The base 10 is made of a silicon substrate. The base 10 intersects and is perpendicular to the Z direction, and extends in the X and Y directions. The base 10 has a surface 10a and a back surface 10b. The surface 10a is an end surface in the Z direction. The surface 10a faces the Z direction, intersects and is perpendicular to the Z direction, and extends in the X and Y directions. The back surface 10b is located on the opposite side of the surface 10a in the Z direction and is an end surface in the opposite direction of the Z direction. The back surface 10b faces the opposite direction of the Z direction, intersects and is perpendicular to the Z direction, and extends in the X and Y directions. The Z direction is an example of a first direction.

[0060] The first protrusion 11 protrudes from the surface 10a of the base 10 in the Z direction. Figure 1 、 2 As shown, the first protrusion 11 forms a planar lightwave circuit (PLC) in which a first cladding layer 11a, a core layer 11b, and a second cladding layer 11c are stacked sequentially in the Z direction. The core layer 11b has a roughly constant height in the Z direction and a roughly constant width in the Y direction, and extends in the X direction. The cross-section of the core layer 11b, taken along the X direction, is a quadrilateral. The core layer 11b can also be called a waveguide layer. The first cladding layer 11a buries both sides of the core layer 11b in the Y direction and the opposite direction, and together with the second cladding layer 11c, surrounds the core layer 11b as a cladding.

[0061] The first cladding layer 11a and the second cladding layer 11c are made of, for example, a quartz glass material. The core layer 11b is made of, for example, a quartz glass material having a higher refractive index than the first cladding layer 11a and the second cladding layer 11c. The core layer 11b can also be made of, for example, quartz glass containing germanium oxide (GeO2) or zirconium oxide (ZrO2) as dopants to increase the refractive index. Furthermore, the relative refractive index difference between the core layer 11b and the first and second cladding layers 11a and 11c can be appropriately set within the range of 0.1 to 10%. The width of the core layer 11b in the Y direction can be set to 0.5 to 5 μm, and the height in the Z direction can be set to 0.5 to 5 μm. As an example, when the relative refractive index difference is set to 0.45%, the cross-sectional dimensions of the core layer 11b in the Y and Z directions are preferably 3 μm x 3 μm.

[0062] The two second protrusions 12 (12-1, 12-2) protrude from the surface 10a of the base 10 in the Z direction. The two second protrusions 12 have the same height from the surface 10a of the base 10 in the Z direction, but are lower than the protrusion height of the first protrusion 11 in the Z direction.

[0063] The two second protrusions 12-1 and 12-2 are separated from each other in the X direction. The second protrusion 12-1 is located on the opposite side of the first protrusion 11 relative to the second protrusion 12-2. The two second protrusions 12-1 and 12-2 are aligned with the first protrusion 11 in the X direction.

[0064] The second protrusion 12 functions as a pedestal for mounting the light-emitting element 20. The end surface 12a of the second protrusion 12, which faces the Z direction and is perpendicular to the Z direction, extends in the X and Y directions. The second protrusion 12 is an example of a supporting portion and can also be referred to as a mounting portion. Furthermore, the end surface 12a can also be referred to as a supporting surface or mounting surface for the light-emitting element 20.

[0065] The two second protrusions 12-1 and 12-2 support the front and rear sides of the light emitting element 20 in the X direction relative to the center in the X direction. The second protrusion 12-1 supports the ends of the light emitting element 20 in the opposite direction in the X direction, and the second protrusion 12-2 supports the ends of the light emitting element 20 in the X direction.

[0066] The second protrusions 12 - 1 and 12 - 2 extend in the Y direction, supporting the light emitting element 20 on both sides of the Y direction relative to the center of the Y direction. However, the present invention is not limited to this, and the second protrusions 12 may be separated in the Y direction, and the separated second protrusions 12 in the Y direction support the light emitting element 20.

[0067] Furthermore, a recess 11e is provided between the second protrusion 12-2, which is closer to the first protrusion 11, and the first protrusion 11. The bottom surface of the recess 11e may be spaced apart from the surface 10a of the base 10 in the Z direction or may be the surface 10a of the base 10.

[0068] The third protrusion 13 protrudes from the surface 10 a of the base 10 in the Z direction. The height of the third protrusion 13 from the surface 10 a of the base 10 in the Z direction is lower than the height of the second protrusion 12 .

[0069] The third protrusion 13 is located between the two second protrusions 12-1 and 12-2, and is aligned with the first protrusion 11 and the two second protrusions 12-1 and 12-2 in the X direction. Furthermore, the third protrusion 13 is adjacent to the second protrusion 12-1, which is located farther from the first protrusion 11, in the X direction and is integrated with the second protrusion 12-1. Together with the second protrusion 12-1, the third protrusion 13 forms a height difference that decreases as it moves in the X and Z directions.

[0070] The Z-direction end surface 13a of the third protrusion 13 faces the Z-direction, intersecting and perpendicular to the Z-direction, and extending in the X- and Y-directions. A thin, film-like electrode 10d is provided on the end surface 13a. Electrode 10d is made of a highly conductive material such as gold. Electrode 10d is an example of a third electrode.

[0071] The fourth protrusion 14 protrudes from the surface 10 a of the base 10 in the Z direction. The height of the fourth protrusion 14 from the surface 10 a of the base 10 is higher than the heights of the two second protrusions 12 and the third protrusion 13 , and is substantially the same as the height of the first protrusion 11 .

[0072] The fourth protrusion 14 is arranged along the X direction with the first protrusion 11, the two second protrusions 12, and the third protrusion 13. The fourth protrusion 14 is located on the opposite side of the third protrusion 13 relative to the second protrusion 12-1, and is also located on the opposite side of the first protrusion 11 relative to the light-emitting element 20. That is, the light-emitting element 20 is located between the first protrusion 11 and the fourth protrusion 14 in the X direction.

[0073] The fourth protrusion 14 is adjacent to the second protrusion 12-1 in the opposite direction of the X direction and is integrated with the second protrusion 12-1. The fourth protrusion 14, the second protrusion 12-1, and the third protrusion 13 form a step that decreases in height in the X and Z directions.

[0074] The Z-direction end surface 14a of the fourth protrusion 14 faces the Z-direction, intersecting and perpendicular to the Z-direction, and extending in the X-direction and the Y-direction. Thin, film-like electrodes 10e and 10f are provided on the end surface 14a. Electrodes 10e and 10f are made of a highly conductive material such as gold. Electrodes 10e and 10f are, for example, locations for electrical connection to external wiring (not shown). In this case, electrodes 10e and 10f can also be referred to as external electrodes. Electrode 10f is an example of a fourth electrode.

[0075] The two second protrusions 12 , the third protrusion 13 , and the fourth protrusion 14 are made of the same material as that of the first cladding layer 11 a and the second cladding layer 11 c .

[0076] On the surface 10a of the base 10, a thin film-like electrode 10c is provided between the two second protrusions 12, that is, between the second protrusion 12-2 and the third protrusion 13. Electrode 10c is made of a highly conductive material such as gold. Electrode 10c is an example of a second electrode.

[0077] The light emitting element 20 is, for example, a laser diode and has a substantially rectangular parallelepiped shape. That is, when viewed in the direction opposite to the Z direction, the light emitting element 20 has a substantially quadrilateral shape.

[0078] The light-emitting element 20 is an example of an optical semiconductor element optically connected to the core layer 11b. The optical semiconductor element optically connected to the core layer 11b is not limited to the light-emitting element 20 and may also be a light-receiving element or a light modulating element. A light modulating element is an element that modulates any of the properties of light by performing spatial modulation, phase modulation, or reverse intensity modulation. Furthermore, the optical semiconductor element may be a structure in which two or more elements selected from a light-emitting element, a light-receiving element, and a light modulating element are integrated.

[0079] The light-emitting element 20 has an end face 20a in the Z direction, an end face 20b in the opposite direction of the Z direction, an end face 20c in the X direction, and an end face 20d in the opposite direction of the X direction. End faces 20a and 20b intersect and are perpendicular to the Z direction and extend in the X and Y directions. Furthermore, end faces 20c and 20d intersect and are perpendicular to the X direction and extend in the Y and Z directions.

[0080] like Figure 2 As shown, the light emitting element 20 includes a cladding layer 21 and an active layer 22. The X-direction end of the active layer 22 faces the core layer 11b of the first protrusion 11. Light emitted from the active layer 22 in the X-direction is coupled to the core layer 11b. The X-direction is an example of a second direction.

[0081] like Figure 3As shown, the active layer 22 extends in the X direction at a fixed width in the Y direction at the center position in the Y direction. Figure 2 As shown, in this embodiment, the active layer 22 is located closer to the end face 20b than the end face 20a. This is merely an example, and the Z-direction position of the active layer 22 can be modified as appropriate. The Z-direction position of the active layer 22 is set so that it faces the core layer 11b in the X-direction and light output from the active layer 22 is coupled to the core layer 11b.

[0082] A thin film-like electrode 23 is provided on the end face 20b of the light-emitting element 20 in the opposite direction of the Z direction. On the other hand, a thin film-like electrode 24 is provided on the end face 20a of the light-emitting element 20 in the Z direction. Both electrodes 23 and 24 are made of a highly conductive material such as gold. In one example, electrode 24 serves as a cathode, and electrode 23 serves as an anode.

[0083] The electrode 24 is electrically connected to the electrode 10 e on the fourth protrusion 14 via a conductive wiring such as a bonding wire (not shown).

[0084] Figure 4 yes Figure 2 An enlarged view of a portion of the Figure 4 As shown, a conductive paste 40 is sandwiched between the electrode 23 and the electrode 10c on the surface 10a of the base 10. The electrode 23 and the electrode 10c are electrically connected via the conductive paste 40. The conductive paste 40 is sandwiched between the electrode 23 and the electrode 10c, for example, in a compressed and deformed state, and is in close contact with both the electrodes 23 and 10c. The electrode 10c is electrically connected to the electrode 10f via a conductor wiring such as a bonding wire (not shown). Therefore, the electrode 23 is electrically connected to the electrode 10f on the fourth protrusion 14 via the conductive paste 40, the electrode 10c and the conductor wiring. The structure having the conductive paste 40 as described above can provide the following advantages: for example, it is possible to relatively easily form a conductor wiring between the electrode 23 and the electrode 10f provided on the end surface 20b on the base 10 side of the light-emitting element 20. The conductive paste 40 is an example of a conductor. The electrode 23 is an example of a first electrode. It should be noted that the electrodes 10c and 10f may also be electrically connected via a conductor wiring such as a bonding wire (not shown) that relays the electrode 10d. In this case, since the conductor wiring can be shorter, advantages such as improved wiring workability and reduced damage to the conductor wiring can be achieved.

[0085] Conductive paste 40 may also contain a thermally conductive filler. In this case, conductive paste 40 also functions as a thermally conductive member. Thermally conductive fillers include particles, powders, nanoparticles, and the like made from electrically conductive and highly thermally conductive metal materials such as gold and silver-based metals. Silver-based metals include silver and silver alloys. Conductive paste 40 may also be, for example, a silver paste containing silver particles as a thermally conductive filler. The above-described structure provides the following advantages: for example, heat generated in light-emitting element 20 can be dissipated toward base 10 via conductive paste 40, thereby easily suppressing excessive temperature increases in light-emitting element 20.

[0086] In addition, if Figure 4 As shown, a rough surface 10g having a greater surface roughness than other portions of surface 10a is provided on the surface 10a of the base 10, in an area separated from the electrode 10c. The conductive paste 40 is also partially in contact with the rough surface 10g. The surface area of ​​the rough surface 10g is larger than that of other portions of surface 10a. Therefore, compared to a case where the conductive paste 40 is in contact with these other portions, the contact area between the base 10 (rough surface 10g, surface 10a) and the conductive paste 40 can be increased. Consequently, the amount of heat transferred from the conductive paste 40 to the base 10 can be further increased. Therefore, this structure provides the advantage of further increasing the amount of heat generated in the light-emitting element 20 that can be transferred to the base 10 via the conductive paste 40, thereby further preventing excessive temperature increases in the light-emitting element 20.

[0087] Figure 5 FIG. 2 is a plan view of a portion of the semiconductor optical device 100A excluding the light emitting element 20. This portion may also be referred to as a heat sink S. FIG.

[0088] like Figure 5 As shown, four marks 30 are provided on the end surfaces 12a of the two second protrusions 12, at least partially exposed on these end surfaces 12a. When an operator or a robot places the light-emitting element 20 on these end surfaces 12a, the marks 30 serve as targets or references for visual confirmation of the placement position by the operator, or for the robot to determine the placement position based on image processing of camera-captured images. The marks 30 can also be referred to as alignment marks.

[0089] like Figure 5As shown, in this embodiment, a plurality of marks 30 are provided on the end surface 12a. In this embodiment, four marks 30 are provided as an example. The light-emitting element 20 is positioned on the second protrusion 12 using these four marks 30 as a reference. Specifically, when viewed in the direction opposite to the Z direction, the light-emitting element 20 is positioned so that the end surface 20e in the Y direction or the direction opposite to the Y direction is adjacent to the mark 30. The end surface 20e is an example of an edge.

[0090] Furthermore, in this embodiment, when viewed from the opposite direction of the Z direction, at a given placement position of the light-emitting element 20, a gap of substantially the same distance can be formed between the two marks 30 arranged in the Y direction on the second protrusion 12-1 and the end face 20e of the light-emitting element 20, with the light-emitting element 20 positioned centrally between the two marks 30. Furthermore, at this given placement position, a gap of substantially the same distance can be formed between the two marks 30 arranged in the Y direction on the second protrusion 12-2 and the end face 20e of the light-emitting element 20, with the light-emitting element 20 positioned centrally between the two marks 30. That is, in this embodiment, when viewed from the opposite direction of the Z direction, the marks 30 and the end face 20e of the light-emitting element 20 are adjacent to each other with a gap therebetween. The marks 30 are both examples of first marks and second marks.

[0091] It should be noted that, when viewed from the opposite Z direction, it is not essential to provide a gap between the mark 30 and the end surface 20e at a given placement position. For example, the edge of the mark 30 and the end surface 20e may completely overlap, or a portion of the mark 30 may overlap the light-emitting element 20. Even in these cases, a portion of the mark 30 and the end surface 20e are adjacent when viewed from the opposite Z direction. It should be noted that, in the case of a structure in which the light-emitting element 20 overlaps a portion of the mark 30, a marking such as a scale mark may be provided on the mark 30.

[0092] In addition, in this embodiment, the mark 30 is made of the same material as the core layer 11b. Next, a method for manufacturing the semiconductor optical device 100A including the mark 30 described above will be described.

[0093] [Manufacturing process of semiconductor optical devices]

[0094] Figure 6 FIG. 1 is a flow chart showing a method for manufacturing the semiconductor optical device 100A. Figure 6As shown, first, quartz glass particles are deposited along the Z direction on the susceptor 10 by, for example, the FHD method (FHD: flame hydrolysis deposition), and the glass particles are heated to be transparently vitrified to form a first layer (S1) including a portion to become the first cladding layer 11a.

[0095] Next, a quartz glass fine particle layer is deposited in the Z direction on the first layer, for example, by sputtering, to form a second layer (S2) including a portion to be the core layer 11b and the markings 30. In this S2, for example, ZrO2 is added to SiO2 so that the refractive index of the core layer 11b is higher than that of the first cladding layer 11a, and the relative refractive index difference is 0.45 [%].

[0096] Next, an etching mask including a pattern of the core layer 11b and a pattern of the mark 30 is formed on the second layer by photolithography, and dry etching (S3) is performed using an etching gas such as a fluorine-based gas for the second layer on which the etching mask has been formed. In this S3, the area exposed from the etching mask is removed, thereby forming the core layer 11b and the mark 30 as a portion covered by the etching mask and not removed in the second layer. Thus, the core layer 11b and the mark 30 are made of the same material as that constituting the second layer. In addition, the ends of the core layer 11b in the opposite direction of the Z direction and the ends of the mark 30 in the opposite direction of the Z direction are both boundaries between the first layer and the second layer. Figure 2 As shown by the dashed line L, the marks 30 are located at the same height in the Z direction from the surface 10a of the base 10. Therefore, the marks 30 are provided so as to be exposed on the end surface 12a and to have a predetermined length (depth) in the opposite direction from the end surface 12a in the Z direction.

[0097] Next, on the laminated body having the core layer 11b and the mark 30 formed on the first layer, quartz glass particles are deposited and heated, for example, by the FHD method to vitrify the glass particles and form a third layer including a portion to become the second cladding layer 11c (S4).

[0098] Next, the stacked body including the first layer, core layer 11b, mark 30, and third layer is subjected to selective removal by, for example, forming an etching mask and dry etching, thereby forming a heat sink S including first protrusion 11, second protrusion 12, third protrusion 13, fourth protrusion 14, and recess 11e (S5). In S5, mark 30 is left on second protrusion 12.

[0099] Next, the electrodes 10 c , 10 d , 10 e , and 10 f are formed on the heat sink S by, for example, sputtering and photolithography ( S6 ).

[0100] Next, the mark 30 is visually recognized or photographed in the direction opposite to the Z direction. Using the mark 30 as a reference, the light-emitting element 20 is placed at a predetermined position corresponding to the mark 30 on the second protrusion 12 and attached to the heat sink S, for example, by bonding (S7). When using the conductive paste 40, the conductive paste 40 is pre-placed on the heat sink S at the position covered by the light-emitting element 20 before the light-emitting element 20 is placed.

[0101] As described above, according to the present embodiment, the mark 30 is provided on the second protrusion 12 and is exposed on the end surface 12 a and is made of the same material as that of the core layer 11 b .

[0102] When a mark is formed using a metal layer through photolithography, as in conventional techniques, the position of the core layer 11b and the mark are determined using separate mask patterns, resulting in reduced positional accuracy between the core layer 11b and the mark. In contrast, according to this embodiment, since the core layer 11b and the mark 30 are formed from the same material, the relative positional relationship between the core layer 11b and the mark 30 can be determined using a single mask pattern. Consequently, according to this embodiment, the positional accuracy between the core layer 11b and the mark 30 can be improved, thereby improving the positional accuracy between the core layer 11b and the mark 30 and, consequently, the core layer 11b and the light-emitting element 20.

[0103] In addition, in this embodiment, the height of the end of the core layer 11b in the opposite direction of the Z direction from the surface 10a of the base 10 in the Z direction (first direction) is the same as the height of the end of the mark 30 in the opposite direction of the Z direction from the surface 10a of the base 10 in the Z direction.

[0104] The above-described features provide evidence that the core layer 11b and the mark 30 are formed using the same second layer formed on the first layer, as in the aforementioned steps S2 and S3. Furthermore, according to this embodiment, compared to, for example, a case where the mark is formed using a metal layer, the following advantages can be achieved: Since individual variations in the position and thickness of the mark 30 in the Z direction can be reduced, the mark 30 can be reliably left in the etching step.

[0105] In addition, as in this embodiment, when viewed in the opposite direction of the Z direction, the mark 30 (first mark) and the end face 20e (edge) of the light-emitting element 20 can be adjacent to each other with a gap therebetween, or the light-emitting element 20 can be located between the two marks 30 (second marks).

[0106] According to the above-described configuration, the marker 30 can be realized with a relatively simple configuration.

[0107] [Second embodiment]

[0108] Figure 7The semiconductor optical device 100B of the second embodiment is Figure 4 Side view of the same part.

[0109] In this embodiment, if Figure 7 As shown, a conductive paste 40 is interposed between the rough surface 10g on the surface 10a of the base 10, the electrode 10c on the surface 10a, the electrode 10d on the end surface 13a of the third protrusion 13, and the electrode 23 on the end surface 20b of the light-emitting element 20. In this way, the conductive paste 40 can also electrically connect the electrode 23 and both the electrodes 10c and 10d. The method of the first embodiment can be appropriately selected ( Figure 4 ) or adopt the same method as in this embodiment. Figure 7 In the illustrated structure, the electrodes 10d and 10f may be electrically connected via conductor wiring such as bonding wires (not shown). In this case, the following advantages can be achieved: since the conductor wiring is shorter and less, the wiring workability is further improved, and the conductor wiring is less likely to be damaged.

[0110] [Third embodiment]

[0111] Figure 8 FIG is a side view of a portion of the semiconductor optical device 100C according to the third embodiment. Figure 8 As shown, in this embodiment, the side surface 15a between the fourth protrusion 14 and the second protrusion 12-1, the side surface 15b between the second protrusion 12-1 and the third protrusion 13, and the side surface 15c between the third protrusion 13 and the base 10, all form surfaces that are inclined in the Z direction as they move in the direction opposite to the X direction. The stepped structure including the side surfaces 15a-15c described above is provided at a position offset in the Y direction relative to the mark 30. For example, when viewed in the direction opposite to the Z direction, the side surface 15b is provided at a position offset in the Y direction relative to the mark 30, toward the side opposite to the light-emitting element 20 in the Y direction or in the direction opposite to the Y direction. Side surface 15b is an example of a first inclined surface, and side surface 15a is an example of a second inclined surface.

[0112] Furthermore, a wiring pattern 16 is provided between end face 14a, side face 15a, end face 12a, side face 15b, end face 13a, side face 15c, and surface 10a, extending along these multiple surfaces with a substantially constant width in the Y direction. Electrode 10f, electrode 10d, and electrode 10c are electrically connected via wiring pattern 16. Wiring pattern 16, like electrodes 10c, 10d, and 10f, is made of a highly conductive material such as gold.

[0113] With the above-described structure, the plurality of electrodes 10c, 10d, and 10f can be electrically connected using the wiring pattern 16 formed on the heat sink S, without resorting to wire bonding. Furthermore, the wiring pattern 16 and the conductive paste 40 enable a relatively simple structure to achieve wiring that electrically connects the electrode 23, which serves as the anode of the light-emitting element 20, and the electrode 10f, which serves as the external electrode. Furthermore, the side surfaces 15a, 15b, and 15c are inclined toward the Z direction as they face the opposite direction to the X direction. This provides advantages over a structure in which the side surfaces 15a, 15b, and 15c extend in the Z direction and are not inclined relative to the Z direction, such as easier formation of the wiring pattern 16, a shorter wiring pattern 16, and lower resistance.

[0114] [Fourth embodiment]

[0115] Figure 9 FIG. 1 is a side view of a semiconductor optical device 100D according to a fourth embodiment. Figure 9 As shown, the Z-direction height of the core layer 11b is higher, thereby increasing the Z-direction depth of the mark 30. In this case, the central axis Axc of the core layer 11b is offset in the opposite Z-direction relative to the central axis Axl of the active layer 22 of the light-emitting element 20 placed on the end surface 12a of the second protrusion 12. Specifically, by forming the mark 30, the second protrusion 12, and the core layer 11b with this offset, the following advantages can be achieved: the depth of the mark 30 from the end surface 12a can be increased, for example, allowing for more reliable formation of the mark 30 and further improving the visibility and camera-based recognition of the mark 30.

[0116] [Fifth embodiment]

[0117] Figure 10 FIG. 1 is a side view of a portion of a semiconductor optical device 100E according to a fifth embodiment. Figure 10 As shown, the X-direction end face 20c of the light emitting element 20 abuts against the X-direction end face 11f of the first protrusion 11, and this abutment positions the light emitting element 20 in the X-direction.

[0118] Furthermore, as in the first embodiment, a recessed portion 11e, recessed in the opposite Z direction, is provided between the first protrusion 11 and the second protrusion 12-2. A concave curved surface (R-shaped corner) may be formed at the end of the end face 11f in the opposite Z direction. Such a concave curved surface is prone to individual variation. In a structure where the end face 20c and the end face 11f abut, the contact between the end face 20c and the concave curved surface may contribute to individual variation in the X-direction position of the light-emitting element 20. In this regard, in this embodiment, the provision of the recessed portion 11e allows the concave curved surface formed at the end of the end face 11f in the opposite Z direction to be offset in the opposite Z direction relative to the light-emitting element 20. Thus, according to this embodiment, the following advantages can be achieved: for example, by causing the end face 20c to abut the concave curved surface, individual variation in the X-direction position of the light-emitting element 20 can be avoided.

[0119] Furthermore, the end face 11f of the first protrusion 11 is inclined at an angle α with respect to the Z direction so that, as it moves toward the X direction, a corner 20c1 of the end face 20c of the light-emitting element 20, located in the opposite direction of the Z direction, abuts against this end face 11f. The active layer 22 of the light-emitting element 20 is relatively fragile compared to the cladding layer 21 and other layers. Therefore, in a structure where the light-emitting element 20 and the first protrusion 11 abut in the X direction, abutment between the active layer 22 and the first protrusion 11 is not preferred. In this regard, in this embodiment, since the end face 11f is inclined so as to move toward the X direction as it moves toward the Z direction, a corner 20c1 of the end face 20c of the light-emitting element 20, offset in the opposite direction of the active layer 22 in the Z direction, abuts against this end face 11f, creating a gap g between the active layer 22 and the end face 11f. The gap between the active layer 22 and the end face 11f is, for example, 1 μm or less. Therefore, this embodiment can provide advantages such as preventing damage by causing the active layer 22 to contact the first protrusion 11. The end face 20c and the corner 20c1 of the light emitting element 20 are examples of the ends of the light emitting element 20 in the X direction.

[0120] [Sixth embodiment]

[0121] Figure 11 FIG is a top view of a semiconductor optical device 100F according to the sixth embodiment. Figure 11 As shown, in this embodiment, as in the fifth embodiment, the end face 20c of the light emitting element 20 in the X direction abuts against the end face 11f of the first protrusion 11 in the opposite direction to the X direction, and the light emitting element 20 is positioned in the X direction by this abutment.

[0122] In this embodiment, the end face 11f of the first protrusion 11 includes a first face 11f1 and a second face 11f2. The first face 11f1 is arranged offset from the core layer 11b in the Y direction and abuts the end face 20c of the light-emitting element 20. Furthermore, the second face 11f2 is arranged adjacent to the first face 11f1 in the direction opposite to the Y direction, and the core layer 11b is exposed in the direction opposite to the X direction with a gap g between it and the end face 20c. The core layer 11b is inclined at an angle β relative to the direction opposite to the Y direction, so that the core layer 11b is inclined toward the X direction as it moves toward the direction opposite to the Y direction. The angle β is, for example, greater than 1 degree and less than 7 degrees. With the above-described structure, a gap g can also be ensured between the active layer 22 and the first protrusion 11. Therefore, according to this embodiment, the following advantages can be obtained, such as the active layer 22 abutting against the first protrusion 11, thereby preventing damage. The Y direction is an example of a third direction.

[0123] Furthermore, in this embodiment, the normal line N (normal direction) of the second surface 11f2 and the central axis Axc (optical axis direction) of the core layer 11b intersect at an angle γ. Angle γ is, for example, not less than 5 degrees and not more than 11 degrees. This embodiment provides the following advantages: For example, return light from the core layer 11b that propagates toward the light-emitting element 20 is reflected by the second surface 11f2 and diffuses in a direction that does not couple with the core layer 11b, thereby suppressing adverse effects caused by the return light.

[0124] [Seventh embodiment]

[0125] Figure 12 FIG. 1 is a top view of a semiconductor optical device 100G according to a seventh embodiment. Figure 13 yes Figure 12 Sectional view XIII-XIII.

[0126] like Figure 12 、 13 As shown, in this embodiment, three light emitting elements 20 that output laser beams of different wavelengths are provided.

[0127] The three light-emitting elements 20 are semiconductor laser elements, such as a red light source, a blue light source, and a green light source. The red light source, for example, outputs red visible light with a wavelength of 620 to 750 nm. The blue light source, for example, outputs blue visible light with a wavelength of 450 to 495 nm. Furthermore, the green light source, for example, outputs green visible light with a wavelength of 495 to 570 nm.

[0128] The three light emitting elements 20 are arranged in the Y direction. Figure 13As shown, the end face 12a of the second protrusion 12-2 has a height difference that increases in the Z direction as it moves toward the Y direction. Specifically, the end face 12a on which the light-emitting element 20-2 is mounted is offset in the Z direction from the end face 12a on which the light-emitting element 20-1 is mounted, and the end face 12a on which the light-emitting element 20-3 is mounted is offset in the Z direction from the end face 12a on which the light-emitting element 20-2 is mounted. Consequently, the end face 20b of the light-emitting element 20-2 is offset in the Z direction from the end face 20b of the light-emitting element 20-1, and the end face 20b of the light-emitting element 20-3 is offset in the Z direction from the end face 20b of the light-emitting element 20-2. The end face 20b is an example of a bottom surface mounted on the end face 12a.

[0129] Furthermore, if Figure 13 As shown in FIG. 1 , in this embodiment, the distance in the Z direction between the end face 20 b of the light emitting element 20-2 and the active layer 22 is longer than the distance in the Z direction between the end face 20 b of the light emitting element 20-3 and the active layer 22, and the distance in the Z direction between the end face 20 b of the light emitting element 20-1 and the active layer 22 is longer than the distance in the Z direction between the end face 20 b of the light emitting element 20-2 and the active layer 22. According to the above-mentioned structure, as Figure 13 As shown, the distances in the Z direction between the surface 10 a and the active layer 22 of the three light-emitting elements 20 - 1 to 20 - 3 are made substantially the same.

[0130] like Figure 12 As shown, three core layers 11b are provided in the first protrusion 11 corresponding to the light-emitting elements 20-1 to 20-3, for coupling the light outputted from the light-emitting elements 20-1 to 20-3. Here, as described above, the semiconductor optical device 100G of this embodiment is configured so that the distances in the Z direction between the surface 10a and the active layer 22 are substantially the same for the three light-emitting elements 20-1 to 20-3. Therefore, the distances in the Z direction between the surface 10a and the core layer 11b can be made the same for the plurality of core layers 11b. Thus, according to this embodiment, the following advantages can be achieved: for example, compared to a case where a plurality of core layers 11b are provided with different distances between the surface 10a and the core layer 11b in the Z direction, the time, effort, and cost for manufacturing the core layer 11b, i.e., the first protrusion 11, and the semiconductor optical device 100G can be reduced.

[0131] [Eighth Embodiment]

[0132] Figure 14 FIG is a top view of a semiconductor optical device 100H according to the eighth embodiment. Figure 14As shown, in this embodiment, the mark 30 is provided adjacent to the corner 20f when viewed from the direction opposite to the Z direction of the light-emitting element 20, with a gap therebetween. Furthermore, the mark 30 is formed in an L-shape, with a portion facing the end face 20d with a gap therebetween in the X direction, and a portion facing the end face 20e with a gap therebetween in the Y direction. This embodiment offers the following advantages: for example, the mark 30 can be used for both positioning the light-emitting element 20 in the X direction and positioning it in the Y direction. The mark 30 in this embodiment is an example of a third mark.

[0133] [Ninth embodiment]

[0134] Figure 15 FIG. 1 is a top view of a portion of a semiconductor optical device 100I according to a ninth embodiment. Figure 16 yes Figure 15 Sectional view XVI-XVI of Figure 15 、 16 As shown, in this embodiment, a recessed groove 31 of a constant width is provided along the periphery of the mark 30. This forms a corner portion at the peripheral edge 30a of the mark 30. This embodiment provides the following advantages: For example, by providing the corner portion at the peripheral edge 30a of the mark 30, compared to a configuration in which neither the recess 31 nor the corner portion is provided at the peripheral edge 30a, the mark 30 can be more easily visually recognized by an operator or a robot when placing the light-emitting element 20 on the end surface 12a, and the mark 30 can be more easily recognized during image processing of a captured image by a camera.

[0135] The above examples illustrate the embodiments and modifications of the present invention, but the above embodiments and modifications are merely examples and are not intended to limit the scope of the invention. The above embodiments and modifications can be implemented in various other ways, and various omissions, substitutions, combinations, and changes can be made without departing from the scope of the invention. In addition, the specifications of each structure, shape, etc. (structure, type, direction, type, size, length, width, thickness, height, number, configuration, position, material, etc.) can be appropriately changed and implemented.

[0136] -Industrial Applicability-

[0137] The present invention can be utilized in a semiconductor optical device and a method for manufacturing the semiconductor optical device.

[0138] -Explanation of symbols-

[0139] 10...base

[0140] 10a...Surface

[0141] 10b...back

[0142] 10c...electrode (second electrode)

[0143] 10d...electrode (third electrode)

[0144] 10e...electrode

[0145] 10f...electrode (fourth electrode)

[0146] 10g...rough noodles

[0147] 11...first protrusion

[0148] 11a...First cladding (cladding)

[0149] 11b...core layer

[0150] 11c...Second cladding (cladding)

[0151] 11e...concave

[0152] 11f...end face

[0153] 11f1...side 1

[0154] 11f2...side 2

[0155] 12, 12-1, 12-2...second protrusion

[0156] 12a...end face

[0157] 13...the third protrusion

[0158] 13a...end face

[0159] 14...Fourth protrusion

[0160] 14a...end face

[0161] 15a...side surface (second inclined surface)

[0162] 15b...side surface (first inclined surface)

[0163] 15c...side

[0164] 16...Wiring pattern

[0165] 20, 20-1, 20-2, 20-3...Light-emitting element (optical semiconductor element)

[0166] 20a...end face

[0167] 20b...end face (bottom face)

[0168] 20c...end face (end)

[0169] 20c1...corner (end)

[0170] 20d...end face

[0171] 20e...end face

[0172] 20f...corner

[0173] 21...cladding

[0174] 22...Active layer

[0175] 23...electrode (first electrode)

[0176] 24...electrode

[0177] 30...marks (first mark, second mark, third mark)

[0178] 30a...periphery

[0179] 31...groove

[0180] 40...Conductive paste (conductor)

[0181] 100A~100I...Semiconductor optical devices

[0182] Axc...(core layer) center axis

[0183] Ax1...Central axis (of the active layer)

[0184] g...gap

[0185] L...single dot dash line

[0186] N...Normal

[0187] S...Heat sink

[0188] X...direction

[0189] Y...direction

[0190] Z...direction (first direction)

[0191] α...angle

[0192] β...angle

[0193] γ...angle.

Claims

1. A semiconductor optical device comprising: a base, intersecting the first direction; a first protrusion protruding from the base in the first direction and having a planar lightwave circuit including a core layer and a cladding layer surrounding the core layer; two second protrusions, each protruding from the base toward the first direction, and arranged with the first protrusion in a second direction intersecting the first direction, and having a height from the base in the first direction lower than that of the first protrusion; an optical semiconductor element placed on the end surface of the second protrusion in the first direction and optically connected to the core layer; a mark, provided on the second protrusion so as to be exposed on the end surface and made of the same material as the core layer; a first electrode provided on an end surface of the optical semiconductor element in a direction opposite to the first direction and located between the two second protrusions; a conductor, which is a conductive paste located between the two second protrusions and electrically connected to the first electrode; a rough surface at a position between the two second protrusions on the end surface of the base in the first direction, in contact with the conductive paste and having a surface roughness greater than that of other portions; a third protrusion protruding from a position of the base between the two second protrusions in the first direction, and having a height from the base in the first direction lower than that of the two second protrusions; as well as The third electrode is provided on an end surface of the third protrusion in the first direction and is electrically connected to the conductor.

2. The semiconductor optical device according to claim 1, wherein The height of the end of the core layer in the direction opposite to the first direction from the base in the first direction is the same as the height of the end of the mark in the direction opposite to the first direction from the base in the first direction.

3. The semiconductor optical device according to claim 1 or 2, wherein: The semiconductor optical device includes a first mark as the mark, the first mark being adjacent to an edge of the optical semiconductor element with a gap therebetween when viewed in a direction opposite to the first direction.

4. The semiconductor optical device according to claim 1 or 2, wherein: The semiconductor optical device has two second marks as the marks, When viewed in the direction opposite to the first direction, the optical semiconductor element is located between the two second marks.

5. The semiconductor optical device according to claim 1 or 2, wherein: The optical semiconductor element has a quadrilateral shape when viewed in a direction opposite to the first direction. The semiconductor optical device includes a third mark as the mark, the third mark being adjacent to a corner portion of the optical semiconductor element when viewed in a direction opposite to the first direction.

6. The semiconductor optical device according to claim 1 or 2, wherein: The semiconductor optical device includes a second electrode provided at a position between the two second protrusions on the end surface of the base in the first direction and electrically connected to the conductor.

7. The semiconductor optical device according to claim 1, wherein The two protrusions are separated in the second direction, Of the two second protrusions, the second protrusion located farther from the first protrusion is integrated with the third protrusion. The semiconductor optical device according to claim 1 , wherein: The semiconductor optical device includes: a fourth protrusion protruding from the base in the first direction on the opposite side of the third protrusion relative to the second protrusion integrated with the third protrusion, and having a height from the base in the first direction higher than that of the two second protrusions; A fourth electrode electrically connected to the third electrode is provided on an end surface of the fourth protrusion in the first direction.

9. The semiconductor optical device according to claim 8, wherein The semiconductor optical device includes: a wiring pattern that is provided over the end surface of the third protrusion in the first direction, the end surface of the second protrusion integrated with the third protrusion in the first direction, and the end surface of the fourth protrusion in the first direction, and electrically connects the third electrode and the fourth electrode.

10. The semiconductor optical device according to claim 9, wherein The semiconductor optical device includes a first inclined surface between the third protrusion and the second protrusion integrated with the third protrusion, the first inclined surface being oriented toward the first direction as it moves toward a direction opposite to the second direction. The wiring pattern has a portion extending along the first inclined surface.

11. The semiconductor optical device according to claim 9 or 10, wherein: The semiconductor optical device includes a second inclined surface between the second protrusion integrated with the third protrusion and the fourth protrusion, the second inclined surface being oriented toward the first direction as it moves toward a direction opposite to the second direction. The wiring pattern has a portion extending along the second inclined surface.

12. The semiconductor optical device according to claim 1 or 2, wherein: The central axis of the core layer is offset in a direction opposite to the first direction with respect to the central axis of the active layer of the optical semiconductor element.

13. The semiconductor optical device according to claim 1 or 2, wherein: The end portion of the optical semiconductor element in the second direction abuts against an end surface of the first protrusion in the direction opposite to the second direction. The semiconductor optical device according to claim 13 , wherein: An end surface of the first protrusion in the direction opposite to the second direction is inclined toward the second direction as it moves toward the first direction, and abuts against an end portion of the optical semiconductor element in the second direction. The semiconductor optical device according to claim 13 , wherein: A recessed portion recessed in a direction opposite to the first direction is provided between the first protrusion and the second protrusion. The semiconductor optical device according to claim 13 , wherein: The end surface of the first protrusion in the direction opposite to the second direction has: a first surface arranged offset from the core layer in a third direction intersecting the first direction and the second direction, and abutting against an end portion of the optical semiconductor element in the second direction; as well as The second surface is adjacent to the first surface in the direction opposite to the third direction, and is inclined relative to the first surface so that the core layer and the end of the optical semiconductor element in the second direction are exposed in the direction opposite to the second direction with a gap therebetween, and is directed toward the second direction as it moves toward the direction opposite to the third direction.

17. The semiconductor optical device according to claim 16, wherein The normal direction of the second surface and the optical axis direction of the core layer intersect obliquely.

18. The semiconductor optical device according to claim 1 or 2, wherein: The semiconductor optical device comprises: The plurality of optical semiconductor elements as the optical semiconductor elements each have a bottom surface placed on the second protrusion and an end surface in the second direction where the active layer is exposed, and the distance between the bottom surface and the active layer in the first direction is different; a plurality of second protrusions serving as the second protrusions, each having a different height from the base in the first direction and each mounting a different optical semiconductor element; as well as The plurality of core layers as the core layer couple light output from different optical semiconductor elements, respectively. The multiple core layers in the first direction are at the same distance from the base, Regarding multiple combinations of the second protrusion and the optical semiconductor element carried on the second protrusion, the distance from the base to the active layer in the first direction is the same, the light output by each optical semiconductor element is coupled with the core layer, and the core layer and the optical semiconductor element are arranged in the second direction.

19. A method for manufacturing a semiconductor optical device, comprising: A step of laminating a first layer on a substrate intersecting the first direction along the first direction to form the first layer, the first layer including a portion to be a part of the cladding of the planar lightwave circuit; a step of forming a second layer by laminating the first layer along the first direction on the first layer, the second layer including a portion serving as a core layer of the planar lightwave circuit; a step of forming the core layer and the mark by selectively removing the second layer of the laminate; forming a third layer to be a part of the cladding layer on a laminated body in which the core layer and the marker are formed on the first layer; A step of forming a first protrusion, two second protrusions, and a third protrusion by selectively removing a laminate of the first layer, the core layer, the mark, and the third layer, wherein the first protrusion includes at least the planar lightwave circuit and protrudes from the base in the first direction, the two second protrusions each protruding from the base in the first direction at a height lower than that of the first protrusion, with the mark exposed at an end surface in the first direction, and the third protrusion protruding from a position of the base between the two second protrusions in the first direction and having a lower height from the base in the first direction than the two second protrusions; forming a first electrode and a third electrode, the first electrode being provided on an end surface of the optical semiconductor element in a direction opposite to the first direction and located between the two second protrusions, and the third electrode being provided on an end surface of the third protrusion in the first direction; a step of placing a conductor, which is a conductive paste electrically connected to the first electrode, between the two second protrusions; and a step of placing the optical semiconductor element positioned relative to the mark on the second protrusion, The third electrode is electrically connected to the conductor, A rough surface is formed at a position between the two second protrusions on the end surface of the base in the first direction, the rough surface being in contact with the conductive paste and having a larger surface roughness than other portions.

Images