Semiconductor optical device

Abstract

A semiconductor optical device may include a semiconductor substrate; a mesa stripe structure extending in a stripe shape along a first direction on the semiconductor substrate and including a contact layer on a top layer; an adjacent layer on the semiconductor substrate adjacent to the mesa stripe structure in a second direction orthogonal to the first direction; a passivation film covering at least a portion of the adjacent layer; a resin layer on the passivation film; an electrode electrically connected to the contact layer and extending continuously from the contact layer to the resin layer; and an inorganic insulating film extending continuously from the resin layer to the passivation film below the electrode, spaced apart from the mesa stripe structure and completely between the electrode and the resin layer.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Japanese Patent Application No. 2019-148456, filed on August 13, 2019, which is expressly incorporated herein by reference. Technical Field

[0003] This disclosure relates to a semiconductor optical device. Background Technology

[0004] A known structure includes a resin layer (such as a polyimide layer) having a dielectric constant lower than that of a semiconductor, disposed beneath a pad electrode to reduce parasitic capacitance caused by the pad electrode to be wire bonded. During wire bonding, the adhesion strength between the pad electrode (including a metal film) and the resin layer may be weakened, and the pad electrode may be peeled off. Therefore, an inorganic insulating film, such as SiN, can be inserted between the top surface of the resin layer and the pad electrode.

[0005] During the formation of pad electrodes on the top surface of the resin layer, a resin layer is formed on the entire surface of the semiconductor optics. An inorganic insulating film is then formed on the entire surface of the resin layer, patterned, and subsequently etched using photoresist. As the resin layer is etched, the photoresist becomes smaller, thus exposing the inorganic insulating film, which is then used as a mask to etch the resin layer. Consequently, the top surface of the resin layer is lowered, and a large height difference (step) appears between the resin layer and the inorganic insulating film. This step leads to the subsequent formation of disconnected electrodes (pad electrodes and electrodes connected to them).

[0006] The purpose of this disclosure is to provide a semiconductor optical device in which electrodes are adhered to a resin layer without degrading characteristics and reliability. Summary of the Invention

[0007] According to some possible implementations, a semiconductor optical device may include a semiconductor substrate; a mesa stripe structure extending in a stripe shape along a first direction on the semiconductor substrate and including a contact layer on a top layer; an adjacent layer on the semiconductor substrate and adjacent to the mesa stripe structure in a second direction orthogonal to the first direction; a passivation film covering at least a portion of the adjacent layer; a resin layer on the passivation film; an electrode electrically connected to the contact layer and extending continuously from the contact layer to the resin layer; and an inorganic insulating film extending continuously from the resin layer to the passivation film below the electrode, spaced apart from the mesa stripe structure and completely between the electrode and the resin layer.

[0008] According to some possible implementations, a semiconductor optical device may include a mesa stripe structure comprising a contact layer; an adjacent layer adjacent to the mesa stripe structure; a passivation film covering at least a portion of the adjacent layer; a resin layer on the passivation film; an electrode electrically connected to the contact layer and extending continuously from the contact layer to the resin layer; and an inorganic insulating film extending from the resin layer to the passivation film below the electrode. Attached Figure Description

[0009] Figure 1 It is a plan view of a semiconductor optical device;

[0010] Figure 2 It is along Figure 1 The cross-sectional view of the semiconductor optical device shown is taken along line II-II;

[0011] Figure 3 yes Figure 2 A cross-sectional view of the semiconductor optical device shown;

[0012] Figure 4 yes Figure 1 A plan view of the semiconductor optical device shown;

[0013] Figure 5 It is along Figure 4 The diagram shows a cross-sectional view of the semiconductor optical device with line VV cut off.

[0014] Figure 6 It is a plan view of a semiconductor optical device;

[0015] Figure 7 It is along Figure 6 The cross-sectional view of the semiconductor optical device shown by line VII-VII;

[0016] Figure 8 It is along Figure 6 The diagram shows a cross-sectional view of the semiconductor optical device taken along line VIII-VIII. Detailed Implementation

[0017] In the following description, some embodiments will be illustrated in detail with reference to the accompanying drawings. Throughout all the drawings used to explain the embodiments, components having identical or the same function have the same reference numerals, and repeated descriptions will be omitted. The drawings used below are for illustrative purposes only and are examples of the embodiments; the dimensions of the drawings do not always correspond to the magnification shown in the examples.

[0018] Figure 1 It is a plan view of a semiconductor optical device. Figure 2 It is along Figure 1 The diagram shows a cross-sectional view of the semiconductor optical device taken along line II-II. Semiconductor optical device 100 is a ridge waveguide type semiconductor laser.

[0019] The semiconductor optical device 100 includes a semiconductor substrate 10 (e.g., an n-type InP substrate). Multiple layers are stacked on the semiconductor substrate 10. These multiple layers include, for example, an active layer 12, a cladding layer 14, and a contact layer 16. Other semiconductor layers (e.g., light confinement layers, etch stop layers, and diffraction grating layers) may exist between the active layer 12 and the cladding layer 14. A lower electrode 18 (e.g., a cathode) is disposed on the back side of the semiconductor substrate 10.

[0020] The multiple layers include a pair of grooves 20 extending in the first direction D1. The pair of grooves 20 are formed by etching the layer above the active layer 12 in the multilayer. A mesa stripe structure M is formed between the pair of grooves 20.

[0021] The semiconductor optical device 100 includes a mesa stripe structure M. The mesa stripe structure M is composed of a stack of portions of various multiple layers. The mesa stripe structure M extends in a stripe shape on the semiconductor substrate 10 in a first direction D1. The mesa stripe structure M includes a contact layer 16 on the top layer.

[0022] The semiconductor optical device 100 includes an adjacent layer 22. The adjacent layer 22 is on the semiconductor substrate 10. In contrast to the mesa stripe structure M, the adjacent layer 22 is adjacent to one of a pair of recesses 20. The adjacent layer 22 is composed of a stack of other portions of various plurality of layers. The adjacent layer 22 is adjacent to the mesa stripe structure M in a second direction D2 orthogonal to a first direction D1.

[0023] The semiconductor optical device 100 also includes another adjacent layer 22B. The adjacent layer 22B has the same structure as the adjacent layer 22 in the thickness direction, but has different planar dimensions. A mesa stripe structure M, sandwiched between a pair of grooves 20, is disposed between the adjacent layers 22 and 22B. The adjacent layers 22 and 22B protect the mesa stripe structure M on both sides.

[0024] Semiconductor optical device 100 includes a passivation film 24. The passivation film 24 is made of, for example, SiO2. The passivation film 24 covers at least a portion of an adjacent layer 22. The passivation film 24 covers the entire plurality of layers except for the contact layer 16. The passivation film 24 extends from the adjacent layer 22 to the side surface of the mesa stripe structure M through one of a pair of grooves 20. The passivation film 24 covers at least a portion of an adjacent layer 22B. The passivation film 24 extends from the adjacent layer 22B to the side surface of the mesa stripe structure M through the other of the pair of grooves 20. The passivation film 24 is formed to avoid at least a portion (e.g., the entire top surface) of the contact layer 16.

[0025] The semiconductor optical device 100 has a resin layer 26. The resin layer 26 is made of a resin such as polyimide, which has a lower dielectric constant than the overlay layer 14. The resin layer 26 is on a passivation film 24. The resin layer 26 includes side surfaces. These side surfaces are inclined. The side surfaces of the resin layer 26 include a first region R1 adjacent to the mesa stripe structure M. The side surfaces of the resin layer 26 include a second region R2 opposite to the mesa stripe structure M. The side surfaces of the resin layer 26 include a third region R3 between the first region R1 and the second region R2. The resin layer 26 includes a top surface surrounded by the side surfaces. The top surface can be rectangular or circular. The top surface of the resin layer 26 is higher than the surface of the passivation film 24.

[0026] The semiconductor optical device 100 includes a top electrode 28. The top electrode 28 consists of a three-layer structure, for example, Ti, Pt, and Au. The top electrode 28 includes a mesa electrode 30 located on a mesa stripe structure M. The mesa electrode 30 overlaps and contacts a contact layer 16 for conduction. The top electrode 28 extends continuously from the contact layer 16 to a resin layer 26.

[0027] The upper electrode 28 includes a pad electrode 32 located on the top surface of the resin layer 26. The pad electrode 32 is a region for bonding leads (not shown) for external electrical connection. Since the resin layer 26 is inserted below the pad electrode 32, the parasitic capacitance caused by the pad electrode 32 can be reduced.

[0028] The upper electrode 28 includes a bridge electrode 34 formed between the mesa electrode 30 and the pad electrode 32. The bridge electrode 34 passes through the side surface of the resin layer 26 (first region R1), through the region between the resin layer 26 and a pair of grooves 20, through one of the pair of grooves 20, and reaches the mesa electrode 30. At least the passivation film 24 is below the bridge electrode 34.

[0029] The semiconductor optical device 100 includes an inorganic insulating film 36. The inorganic insulating film 36 is made of a different material (e.g., SiN) than the passivation film 24. The inorganic insulating film 36 covers the entire top surface of the insulating film 24. The inorganic insulating film 36 is completely inserted between the upper electrode 28 and the resin layer 26. That is, the upper electrode 28 does not contact the resin layer 26 through the inorganic insulating film 36.

[0030] When the pad electrode 32 and the resin layer 26 are in direct contact, adhesion may be insufficient, and there is a concern that the pad electrode 32 may peel off through the bonding of the leads (not shown). Therefore, it is effective to insert an inorganic insulating film 36 between the pad electrode 32 and the resin layer 26. Inserting the inorganic insulating film 36 between the pad electrode 32 and the bridge electrode 34 and the resin layer 26 enhances the adhesion between the resin layer 26 and the upper electrode 28. By forming the inorganic insulating film 36 to cover the resin layer 26 after forming it in a mountain shape, the step that could cause the upper electrode 28 to break off is eliminated, and the deterioration of characteristics and reliability can be avoided.

[0031] An inorganic insulating film 36 extends continuously from the resin layer 26 to the passivation film 24 below the upper electrode 28. The inorganic insulating film 36 covers the portion of the passivation film 24 adjacent to the resin layer 26. Additionally, an inorganic insulating film 36 is also provided between the bridge electrode 34 and the passivation film 24. From the viewpoint of eliminating the aforementioned steps, the inorganic insulating film 36 could cover only the area where the resin layer 26 is not present (i.e., the area extending to the lower end of the side surface). However, in a design where the inorganic insulating film 36 is only provided at the lower end of the side surface, due to manufacturing errors, the inorganic insulating film 36 may be interrupted in the middle of the side surface. Therefore, a portion of the inorganic insulating film 36 extends onto the passivation film 24 at its edge.

[0032] The inorganic insulating film 36 is spaced apart from the mesa stripe structure M. Therefore, the passivation film 24 is exposed from the inorganic insulating film 36 in the portion away from the resin layer 26 in the direction approaching the mesa stripe structure M. In the region where the inorganic insulating film 36 and the passivation film 24 overlap, both the inorganic insulating film 36 and the passivation film 24 are harder than the semiconductor, and therefore they may cause stress and lead to reliability and characteristic degradation. Therefore, the passivation film 24 is not covered by the inorganic insulating film 36 near the mesa stripe structure M.

[0033] The inorganic insulating film 36 covers only a portion of the surface of the resin layer 26. The inorganic insulating film 36 avoids overlapping with a portion of the side surface of the resin layer 26. The inorganic insulating film 36 covers the first region R1 of the resin layer 26 while avoiding overlap with the second region R2 of the resin layer 26. The inorganic insulating film 36 avoids overlapping with the third region R3 of the resin layer 26. In the second region R2 and the third region R3, where the bridge electrode 34 is not provided, disconnection of the upper electrode 28 is not a problem, and the inorganic insulating film 36 is not provided to reduce stress on the entire semiconductor optical device 100.

[0034] Figure 3 yes Figure 2The diagram shows a cross-sectional view of the semiconductor optical device. In a modified example, adjacent layer 222 includes a recess 238 on the top surface. The recess 238 is formed by scraping the contact layer 216 and the overlay layer 214. The inner surface of the recess 238 is covered with a passivation film 224. A resin layer 226 is disposed in the recess 238 and also on the passivation film 224.

[0035] The thickness of resin layer 226 is greater than the depth of recess 238. The thickness of resin layer 226 is greater than the distance from the top surface of passivation film 224 in recess 238 to the top surface of passivation film 224 surrounding recess 238. Resin layer 226 is placed on passivation film 224 surrounding recess 238. Resin layer 226 is higher than passivation film 224 surrounding recess 238. By forming a thick resin layer 226, parasitic capacitance can be further reduced.

[0036] Figure 4 yes Figure 1 The diagram shows a plan view of a semiconductor optical device. Figure 5 It is along Figure 4 The image shows a cross-sectional view of the semiconductor optics taken from the VV line. In the modified example, the inorganic insulating film 336 covers the entire surface of the resin layer 326.

[0037] Specifically, the inorganic insulating film 336 is shaped to cover the entire top and side surfaces of the resin layer 326. The inorganic insulating film 336 is also placed on the passivation film 324 surrounding the resin layer 326. Because the entire resin layer 326 is covered by the inorganic insulating film 336, deformation of the resin layer 326 during formation can be prevented. Since the resin layer 326 is not etched after patterning, it can more stably maintain its shape without creating steps, and the possibility of the upper electrode 328 being disconnected can be eliminated.

[0038] Figure 6 It is a plan view of a semiconductor optical device. Figure 7 It is along Figure 6 The cross-sectional view of the semiconductor optical device shown along line VII-VII. Figure 8 It is along Figure 6 The cross-sectional view of line VIII-VIII of the semiconductor optical device shown.

[0039] In the semiconductor optics 400, continuous light emitted by the laser portion 442 is modulated by the modulator portion 442 by injecting a drive current, and signal light is output. The semiconductor optics 400 is a modulator-integrated semiconductor optics (e.g., a modulator-integrated laser), wherein the laser portion 440 (e.g., a semiconductor laser) and the modulator portion 442 are monolithically integrated on the same semiconductor substrate 410.

[0040] Laser section 440 is a distributed feedback semiconductor laser (DFB laser). Modulator section 442 is an electro-absorption modulator (EA modulator). Besides its advantageous characteristics of low chirp (wave modulation), large extinction ratio (i.e., the difference between the ON and OFF levels of the optical signal), and wide bandwidth, EA modulators are widely used due to their small size and low cost. Semiconductor optics device 400 is a DFB laser device integrating an EA modulator.

[0041] Semiconductor optical device 400 has a buried heterostructure (BH structure). A BH structure refers to a structure in which a semi-insulating semiconductor layer (adjacent layer 422) is buried on both sides of a mesa-shaped fringe structure M having an optical waveguide. The BH structure has a strong effect of confining light in the lateral direction, and the far-field pattern (FFP) becomes more rounded in the BH structure. Therefore, the BH structure has the advantage of high coupling efficiency with optical fibers and further excellent heat dissipation, making it widely used.

[0042] Semiconductor optical device 400 includes a semiconductor substrate 410. The semiconductor substrate 410 is made of a semiconductor doped with n-type impurities (e.g., n-type InP). The semiconductor substrate 410 includes protrusions 444. The protrusions 444 extend in a stripe shape in a first direction D1. The protrusions 444 at least constitute the lower end of the mesa stripe structure M.

[0043] The mesa stripe structure M includes a first mesa stripe structure M1 for constituting the laser section 440 (semiconductor laser). The mesa stripe structure M also includes a second mesa stripe structure M2 for constituting the modulator section 442.

[0044] The semiconductor optical device 400 has a quantum well layer 412 extending in a stripe shape along a first direction D1 on a protrusion 444. The quantum well layer 412 is made of an intrinsic semiconductor undoped with p-type or n-type impurities. The quantum well layer 412 forms part of a mesa stripe structure M. In the semiconductor laser (first mesa stripe structure M1), the quantum well layer 412 is the active layer. In the modulator section 442 (second mesa stripe structure M2), the quantum well layer 412 is the absorption layer. The quantum well layer 412 is a multiple quantum well (MQW) layer. When an electric field is applied to the MQW layer, the quantum confined Stark effect (QCSE) is obtained, in which the absorption edge of light in the MQW layer shifts towards the longer wavelength side. The EA modulator uses QCSE to modulate light. The MQW layer includes multiple quantum well layers 412 (InGaAsP) with introduced strain and barrier layers, each barrier layer being inserted between adjacent quantum well layers 412.

[0045] Above and below the quantum well layer 412, light-guiding layers (not shown) made of InGaAsP are provided. The quantum well layer 412 (active layer) of the laser section 440 and the quantum well layer 412 (absorption layer) of the modulator section 442 are optically connected by docking. In the laser section 440, a diffraction grating layer made of InGaAsP is disposed on the quantum well layer 412 (active layer).

[0046] The mesa stripe structure M includes a cladding layer 414 extending in a stripe shape along a first direction D1 on the quantum well layer 412 (the diffraction grating layer in the laser section 440). The cladding layer 414 is made of a zinc-doped semiconductor (p-type InP), where zinc is a p-type impurity. The mesa stripe structure M includes a contact layer 416. The contact layer 416 consists of a p-type InGaAsP layer and a p-type InGaAs layer, and each layer is doped with a p-type impurity (Zn).

[0047] The semiconductor optical device 400 includes an adjacent layer 422 as a buried layer. The adjacent layer 422 is made of an iron (Fe)-doped semiconductor (e.g., InP). Fe-doped InP is a semi-insulating semiconductor. The adjacent layer 422 is placed on the top surface of the semiconductor substrate 410. The adjacent layer 422 is adjacent to each of the two sides of the mesa stripe structure M in a second direction D2 orthogonal to the first direction D1, and forms a buried heterostructure. The semiconductor optical device 400 is a mesa stripe type.

[0048] The adjacent layer 422 includes an inclined surface 446 adjacent to the top surface of the mesa stripe structure M and inclined along the plane orientation of the (111) plane. The inclined surface 446 is inclined upward in a direction away from the mesa stripe structure M. The adjacent layer 422 includes a flat surface 448 outside the inclined surface 446 and extending parallel to the horizontal surface.

[0049] The mesa stripe structure M and the adjacent layer 422 are covered by a passivation film 424. The passivation film 424 includes a via 450. In the via 450, the top surface of the mesa stripe structure M (contact layer 416) is exposed, and a portion of the top surface of the adjacent layer 422 (tilted surface 446) is also exposed adjacent to it. The passivation film 424 avoids overlapping with the tilted surface 446.

[0050] A resin layer 426 is disposed on the adjacent layer 422 and the passivation film 424 in the modulator section 442. In contrast, no resin layer is provided in the laser section 440. The reason is that since a DC voltage for emitting continuous light is applied to the laser section 440, the effect of parasitic capacitance in the laser section 440 is minimal.

[0051] The upper electrode 428 of the modulator section 442 is placed on the passivation film 424. The upper electrode 428 is electrically connected to the contact layer 416 in the via 450. The upper electrode 428 includes a mesa electrode 430, a pad electrode 432, and a bridge electrode 434. The semiconductor optical device 400 includes an anti-reflective film (not shown) on the end surface from which light is emitted, and a high-reflective film (not shown) on the end surface opposite to the end surface.

[0052] The foregoing disclosure provides illustrations and descriptions, but is not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. Modifications and variations may be made in light of the foregoing disclosure, or may be derived from practice of the embodiments.

[0053] Even though specific combinations of features are described and / or disclosed in this application, these combinations are not intended to limit the disclosure of various implementations. In fact, many of these features can be combined in ways not specifically described and / or disclosed in this application. Although the implementations listed below may depend directly on only one of the implementations, the disclosure of various implementations includes every implementation combined with every other implementation in the set of said implementations.

[0054] Unless explicitly stated otherwise, no element, action, or instruction used herein should be construed as essential or necessary. Furthermore, as used herein, the articles “a” and “an” are intended to include one or more items and are interchangeable with “one or more.” Additionally, as used herein, the article “the” is intended to include one or more items referenced in combination with the article “the” and is interchangeable with “one or more.” Furthermore, as used herein, the term “set” is intended to include one or more items (e.g., related items, unrelated items, a combination of related and unrelated items, etc.) and is interchangeable with “one or more.” Figure 1 In cases involving an item, the phrase “only one” or similar language is used. Additionally, as used herein, the terms “has,” “have,” “having,” etc., are intended to be open-ended terms. Furthermore, the phrase “based on” is intended to mean “at least partially based on”, unless otherwise explicitly stated. Additionally, as used herein, the term “or” is intended to be inclusive when used in series and may be used interchangeably with “and / or”, unless otherwise explicitly stated (e.g., if used in combination with “or” or “only one of them”).

Claims

1. A semiconductor optical device, comprising: Semiconductor substrate; A mesa stripe structure that extends in a stripe shape along a first direction on a semiconductor substrate and includes a contact layer on a top layer; An adjacent layer, which is on the semiconductor substrate and adjacent to the mesa stripe structure in a second direction orthogonal to the first direction; A passivation film that covers at least a portion of an adjacent layer; A resin layer on a passivation film; An electrode that is electrically connected to the contact layer and extends continuously from the contact layer to the resin layer; and An inorganic insulating film extends continuously from the resin layer to the passivation film beneath the electrode and is completely situated between the electrode and the resin layer. The inorganic insulating film includes a first edge and a second edge opposite to the first edge, wherein the first edge extends along a first direction between the second edge and the mesa stripe structure. The passivation film is covered by the inorganic insulating film in the portion adjacent to the resin layer, and is exposed from the inorganic insulating film in the portion separated from the resin layer in a direction close to the tabletop stripe structure.

2. The semiconductor optical device according to claim 1, wherein... Multiple layers are stacked on a semiconductor substrate. The plurality of layers include a pair of grooves extending in a first direction. The tabletop stripe structure is composed of layers of portions of multiple layers between the pair of grooves. The adjacent layer is adjacent to one of the pair of grooves opposite to the tabletop stripe structure, and is composed of stacks of other portions of each of the multiple layers.

3. The semiconductor optical device according to claim 2, wherein, The passivation film extends from the adjacent layer through the pair of grooves to the side surface of the mezzanine stripe structure.

4. The semiconductor optical device according to claim 1, wherein, The adjacent layer is adjacent to the tabletop stripe structure and forms a buried heterogeneous structure.

5. The semiconductor optical device according to claim 4, wherein... Adjacent layers include inclined surfaces that slope upwards in a direction away from the tabletop stripe structure, and The passivation film does not overlap with the inclined surface.

6. The semiconductor optical device according to claim 1, wherein, The inorganic insulating film covers only a portion of the surface of the resin layer.

7. The semiconductor optical device according to claim 6, wherein... The resin layer includes a side surface and a top surface surrounded by the side surface, and The inorganic insulating film does not overlap with a portion of the side surface.

8. The semiconductor optical device according to claim 7, wherein The side surface of the resin layer includes a first region adjacent to the tabletop stripe structure and a second region opposite to the tabletop stripe structure. The inorganic insulating film covers the first region and does not overlap with the second region.

9. The semiconductor optical device according to claim 8, wherein... The side surface of the resin layer also includes a third region between the first and second regions, and The inorganic insulating film does not overlap with the third region.

10. The semiconductor optical device according to claim 7, wherein, The inorganic insulating film covers the entire top surface.

11. The semiconductor optical device according to claim 1, wherein, The inorganic insulating film covers the entire surface of the resin layer.

12. The semiconductor optical device according to claim 1, wherein... Adjacent layers include recesses. The passivation film is arranged to reach the recess, and The resin layer is located on the recess.

13. A semiconductor optical device, comprising: A tabletop stripe structure, the tabletop stripe structure including a contact layer; Adjacent layer, which is adjacent to the tabletop stripe structure; A passivation film that covers at least a portion of an adjacent layer; A resin layer on a passivation film; An electrode that is electrically connected to the contact layer and extends continuously from the contact layer to the resin layer; and An inorganic insulating film extending from the resin layer to a passivation film beneath the electrode. The inorganic insulating film includes a first edge and a second edge opposite to the first edge, wherein the first edge extends in one direction between the second edge and the mesa stripe structure. The passivation film is covered by the inorganic insulating film in the portion adjacent to the resin layer, and is exposed from the inorganic insulating film in the portion separated from the resin layer in a direction close to the tabletop stripe structure.

14. The semiconductor optical device according to claim 13, wherein, The adjacent layer includes an inclined surface that slopes upward in a direction away from the tabletop stripe structure.

15. The semiconductor optical device according to claim 13, wherein, The inorganic insulating film covers only a portion of the surface of the resin layer.

16. The semiconductor optical device according to claim 13, wherein, The inorganic insulating film does not overlap with a portion of the side surface of the resin layer.

17. The semiconductor optical device according to claim 16, wherein... The side surface of the resin layer includes a first region adjacent to the tabletop stripe structure and a second region opposite to the tabletop stripe structure. The inorganic insulating film covers the first region and does not overlap with the second region.

18. The semiconductor optical device according to claim 17, wherein... The side surface of the resin layer also includes a third region between the first and second regions, and The inorganic insulating film does not overlap with the third region.

19. The semiconductor optical device according to claim 13, wherein Adjacent layers include recesses. The passivation film is configured to reach the recess, and The resin layer is on the recess.

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