Semiconductor optical device and optical integrated element

Abstract

The semiconductor optical device includes, for example, a substrate extending across a first direction; and a plurality of waveguide structures each having a first cladding layer, a core layer, and a second cladding layer stacked in a first direction on the substrate, the waveguide structures extending in a second direction intersecting the first direction and guiding light in the second direction or in a direction opposite to the second direction, the first and second electrodes are separated from each other in a third direction intersecting with the first and second directions. And a first electrode provided on the opposite side from the substrate with respect to each waveguide structure, the first electrode having a first portion and a second portion thicker in the first direction than the first portion.

Description

Technical Field

[0001] The present invention relates to semiconductor optical devices and optical integrated components. Background Art

[0002] Conventionally, there is known an optical integrated device that integrally includes a semiconductor laser element, a semiconductor optical device such as a semiconductor optical amplifier, and a portion having a waveguide (hereinafter referred to as an optical functional element) (for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-92262 Summary of the Invention

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

[0007] This type of semiconductor optical device includes a semiconductor layer forming a waveguide structure and a metal layer forming an electrode. If there is a significant temperature difference between the manufacturing and operation of this semiconductor optical device, a difference in the degree of thermal contraction will occur depending on the location of the device, corresponding to the difference in the thermal expansion coefficients of the semiconductor layer and the metal layer. This can cause the semiconductor optical device to deform from its intended shape. This deformation is hereinafter referred to as thermal deformation. Thermal deformation can include, for example, warping of the semiconductor optical device, where the device deforms convexly or concavely in the direction of the waveguide structure's stacking.

[0008] In a semiconductor optical device having only a single waveguide, even when thermal deformation occurs as described above, the optical loss between the waveguide and its corresponding waveguide can be suppressed by positioning the waveguide of another optical component, etc., optically connected to the waveguide (hereinafter referred to as the corresponding waveguide). However, in a semiconductor optical device having multiple waveguides, thermal deformation causes the relative positional relationship of the multiple waveguides to change, making it difficult to suppress the reduction of optical loss between each waveguide and its corresponding waveguide.

[0009] For example, reducing the volume of the metal layer that constitutes the electrode can suppress the thermal deformation described above. However, reducing the volume of the metal layer can lead to problems such as a smaller cross-sectional area of ​​the electrode, which increases resistance, or a smaller surface area of ​​the electrode, which reduces heat dissipation and makes it difficult to achieve the desired performance.

[0010] Therefore, one of the objects of the present invention is to provide a new and improved semiconductor optical device and optical integrated element that can suppress an increase in resistance in electrodes and a decrease in heat dissipation due to the electrodes while suppressing thermal deformation, for example.

[0011] -Methods for solving the problem-

[0012] The semiconductor optical device of the present invention, for example, comprises: a substrate extending crosswise to a first direction; a plurality of waveguide structures, each having a first cladding layer, a core layer and a second cladding layer stacked in the first direction on the substrate, extending in a second direction crosswise to the first direction and guiding light in the second direction or in a direction opposite to the second direction, and being arranged separately from each other in a third direction crosswise to the first direction and the second direction; and a first electrode arranged on the side opposite to the substrate relative to each of the waveguide structures, having a first portion and a second portion having a thickness in the first direction that is thicker than the first portion.

[0013] The semiconductor optical device may also include, as the first electrode, a first electrode extending along the second direction with a first width, the second portion extending along the second direction at least partially with a second width narrower than the first width, and the first portion and the second portion being arranged at least partially along the third direction.

[0014] The semiconductor optical device may also include a first electrode as the first electrode, wherein the first electrode extends along the second direction with a first width, the second portion extends along the second direction with a second width narrower than the first width, and the first portion and the second portion are at least partially arranged along the third direction.

[0015] The semiconductor optical device may include, as the first electrode, a first electrode extending along the second direction with a first width, wherein the second portion extends along the second direction with a second width narrower than the first width at least partially at a position aligned with the core layer in the first direction.

[0016] The semiconductor optical device may also, as the first electrode, include the following first electrode: extending along the second direction with a first width, and the second portion extending along the second direction with a second width narrower than the first width at a position deviated toward the third direction or the opposite direction of the third direction relative to the center of the first electrode in the third direction.

[0017] The semiconductor optical device may include, as the first electrode, a first electrode extending in the second direction, wherein the second portion extends longer in the second direction than the first portion.

[0018] The semiconductor optical device may include, as the first electrode, a first electrode having a first layer constituting the first portion and a portion of the second portion, and a second layer constituting a portion of the second portion on the opposite side of the first layer from the waveguide structure.

[0019] The semiconductor optical device may include a waveguide structure constituting an active waveguide as the waveguide structure.

[0020] The semiconductor optical device may include, as the waveguide structure, two waveguide structures optically connected via a folded waveguide structure.

[0021] In the semiconductor optical device, the folded-back waveguide structure may constitute a passive waveguide.

[0022] The semiconductor optical device may include a plurality of waveguide structure components, each of the plurality of waveguide structure components including the folded waveguide structure and two waveguide structures optically connected via the folded waveguide structure.

[0023] The semiconductor optical device may include, as the waveguide structure, two waveguide structures arranged in the third direction with a groove extending in the second direction interposed therebetween.

[0024] The semiconductor optical device may include a recessed portion that is recessed in a direction opposite to the first direction and reaches the substrate, and may include a second electrode that is at least partially provided in the recessed portion.

[0025] In the semiconductor optical device, the second electrode may include a third portion and a fourth portion that is thicker than the third portion.

[0026] In the semiconductor optical device, the fourth portion may include an extension portion extending in the first direction along a side surface of the recessed portion.

[0027] The semiconductor optical device may further include a semiconductor optical amplifier having the waveguide structure and an electrode pair provided corresponding to the waveguide structure.

[0028] The semiconductor optical device may further include a semiconductor light emitting element having the waveguide structure and a pair of electrodes provided corresponding to the waveguide structure.

[0029] Furthermore, the optical integrated component of the present invention may integrally include: the semiconductor optical device; and an optical functional element having a waveguide optically connected to the waveguide structure of the semiconductor optical device.

[0030] -Effects of the Invention-

[0031] According to the present invention, new and improved semiconductor optical devices and optical integrated components can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1It is an illustrative and schematic cross-sectional view of the semiconductor optical device according to the first embodiment.

[0033] Figure 2 It is an illustrative and schematic top view of the semiconductor optical device according to the first embodiment.

[0034] Figure 3 It is an illustrative and schematic top view of the semiconductor optical device according to the second embodiment.

[0035] Figure 4 It is an illustrative and schematic top view of a semiconductor optical device according to a third embodiment.

[0036] Figure 5 yes Figure 4 VV cross-sectional view.

[0037] Figure 6 It is an illustrative and schematic top view of a semiconductor optical device according to a fourth embodiment.

[0038] Figure 7 It is an illustrative and schematic top view of a semiconductor optical device according to a fifth embodiment.

[0039] Figure 8 yes Figure 7 Sectional view VIII-VIII of FIG.

[0040] Figure 9 It is an illustrative and schematic cross-sectional view of a semiconductor optical device according to a sixth embodiment.

[0041] Figure 10 It is an illustrative and schematic top view of a semiconductor optical device according to a sixth embodiment.

[0042] Figure 11 This is an illustrative and schematic plan view of an optical integrated component including the semiconductor optical device and the optical functional element according to the seventh embodiment. DETAILED DESCRIPTION

[0043] The following discloses exemplary embodiments of the present invention. The structures of the embodiments described below, as well as the functions and results (effects) resulting from these structures, are merely examples. The present invention can also be implemented using structures other than those disclosed in the following embodiments. Furthermore, the present invention can achieve at least one of the various effects (including derivative effects) derived from these structures.

[0044] A plurality of embodiments shown below possess the same structure. Therefore, according to the structure of each embodiment, the same action and effect based on this same structure can be obtained. In addition, below, sometimes the same reference numerals are used to mark the same structures as these, and repeated description is omitted.

[0045] In this specification, ordinal numbers are given for the purpose of distinguishing directions, locations, etc., and do not indicate priority or order, nor do they limit the number.

[0046] In each figure, 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, Y, and Z directions intersect and are orthogonal to each other. Hereinafter, the X direction will be referred to as the longitudinal direction or extension direction, the Y direction will be referred to as the short side direction or width direction, and the Z direction will be referred to as the stacking direction or height direction.

[0047] In addition, each figure is a schematic diagram for explanation purposes, and the scales and ratios in each figure may not necessarily match the actual objects.

[0048] [First embodiment]

[0049] [Basic structure]

[0050] Figure 1 is a cross-sectional view of the semiconductor optical device 100A ( 100 ) according to the first embodiment. Figure 2 This is a top view of the semiconductor optical device 100A (100). Figure 1 yes Figure 2 II sectional view.

[0051] like Figure 1 、 2 As shown, the semiconductor optical device 100A includes a substrate 10, two waveguide structures 20 (20-1, 20-2) and electrodes 30, 40A (40). The electrode 40A, substrate 10, waveguide structure 20-1, insulating layer 23 and electrode 30 constitute a functional portion 101, and the electrode 40A, substrate 10, waveguide structure 20-2, insulating layer 23 and electrode 30 constitute another functional portion 101. For each functional portion 101, the substrate 10 and electrode 40A are shared, and the waveguide structure 20, insulating layer 23 and electrode 30 are provided separately. However, since the structures and functions of the functional portions 101 of both sides are roughly the same, the following only describes one side (in Figure 1 In the present embodiment, a groove 100a is provided between two functional portions 101.

[0052] The substrate 10 has a substantially constant thickness in the Z direction and extends transversely to the Z direction. The substrate 10 is made of, for example, n-InP. The layers forming the waveguide structure 20, the insulating layer 23, and the electrode 30 are stacked on the substrate 10 along the Z direction using a known semiconductor process. The Z direction can be referred to as a stacking direction, a thickness direction, or a height direction. The Z direction is an example of a first direction.

[0053] An electrode 40 is provided on the surface of the substrate 10 on the opposite side in the Z direction. The electrode 40 is an N-side electrode and is separated from the core layer 21b in the opposite direction in the Z direction. The electrode 40 has a stacked structure including, for example, AuGe, Ni, and Au. The electrode 40 is an example of a second electrode.

[0054] A mesa 21 including a cladding layer 21a, a core layer 21b, and a cladding layer 21c is formed on the surface of the substrate 10 opposite the electrode 40. The cladding layer 21a, the core layer 21b, and the cladding layer 21c are stacked in sequence along the Z direction on the substrate 10. The mesa 21 extends in the X direction with a substantially constant width in the Y direction and a substantially constant height in the Z direction.

[0055] The cladding layer 21a is laminated on the substrate 10. The cladding layer 21a is made of, for example, n-InP. The core layer 21b is laminated on the cladding layer 21a. The core layer 21b has, for example, a laminated structure including n-InGaAsP. The cladding layer 21c is laminated on the core layer 21b. The cladding layer 21c is made of, for example, p-InP. The cladding layer 21a is an example of a first cladding layer, and the cladding layer 21c is an example of a second cladding layer.

[0056] The mesa 21 is surrounded by current-blocking layers 22a and 22b adjacent to each other in the Y direction and the direction opposite to the Y direction, and a cladding layer 22c adjacent to each other in the Z direction. The current-blocking layer 22a is made of, for example, p-InP, and the current-blocking layer 22b is made of, for example, n-InP. Furthermore, the cladding layer 22c is made of, for example, p-InP. The cladding layer 22c is an example of a second cladding layer.

[0057] The waveguide structure 20 including the cladding layer 21a, the core layer 21b, the cladding layer 21c, the current blocking layers 22a and 22b, and the cladding layer 22c is covered with an insulating layer 23. The insulating layer 23 has an opening 23a at a position overlapping the mesa 21 in the Z direction. The structures of the waveguide structure 20 and the insulating layer 23 are not limited to this example.

[0058] Each waveguide structure 20 extends in the X direction, guiding light in the X direction or in a direction opposite to the X direction. Furthermore, the two waveguide structures 20 ( 20 - 1 , 20 - 2 ) are separated from each other in the Y direction and arranged in the Y direction with the groove 100 a interposed therebetween. The X direction is an example of the second direction, and the Y direction is an example of the third direction.

[0059] An electrode 30 made of a conductor is provided on the side of each waveguide structure 20 opposite the substrate 10 relative to the cladding layer 22c. The electrode 30 is a P-side electrode and is separated from the core layer 21b in the Z direction. The electrode 30 includes a first layer 30a and a second layer 30b stacked on the first layer 30a. The first layer 30a is in contact with the cladding layer 22c via an opening 23a provided in the insulating layer 23. The first layer 30a is also called a thin film layer, and the second layer 30b is also called a thick film layer. The electrode 30 is an example of a first electrode. The electrode 30 and the electrode 40 together constitute an electrode pair.

[0060] The functional portion 101 of the above structure can function as, for example, a semiconductor optical amplifier. These semiconductor optical amplifiers amplify light input from one end of the core layer 21b and output it from the other end. Therefore, the semiconductor optical device 100A constitutes a semiconductor optical amplifier array. In this case, the core layer 21b of the functional portion 101 is also referred to as an active layer, an example of an active waveguide.

[0061] [Electrode Structure]

[0062] Here, if Figure 1 As shown, the second layer 30b partially covers the first layer 30a. Thus, the electrode 30 is configured to have a first portion 31 having only the first layer 30a and a second portion 32 including the first layer 30a and the second layer 30b and being thicker than the first portion 31. Here, assuming that the electrode 30 is composed only of the thick second portion 32, thermal deformation may become greater. On the contrary, if the electrode 30 is composed only of the thin first portion 31, the cross-sectional area of ​​the electrode 30 may become smaller and the resistance may increase, or the surface area of ​​the electrode 30 may become smaller and the heat dissipation may decrease. In this regard, according to this embodiment, by having the electrode 30 having a relatively thin first portion 31 and a relatively thick second portion 32, thermal deformation can be suppressed, and an increase in resistance and a decrease in heat dissipation can be suppressed.

[0063] Furthermore, in the case of a plurality of waveguide structures 20 separated in the Y direction, as in the present embodiment, if the relative positions of the core layers 21b of each waveguide structure 20 change due to thermal deformation, this has an effect on reducing the optical coupling efficiency between the core layer 21b and the waveguide corresponding to the core layer 21b. Here, the thermal deformation of the deformation mode in which the position of each layer in the Z direction changes as it moves toward the Y direction (hereinafter referred to as the second deformation mode) has a greater impact on the change in the relative positions of the plurality of core layers 21b than the thermal deformation of the deformation mode in which the position of each layer in the Z direction changes as it moves toward the X direction (hereinafter referred to as the first deformation mode). Therefore, in the present embodiment, as Figure 2As shown, the electrode 30 extends in the X-direction with a width W1, and the second portion 32 extends in the X-direction with a width W2 that is narrower than width W1. In other words, the first portion 31 and the second portion 32 both extend in the X-direction and are aligned with each other in the Y-direction. If the second portion 32 extends in the Y-direction, it will contract further in the Y-direction due to the decrease in operating temperature compared to that during manufacturing. Therefore, in the semiconductor optical device 100, the deformation in the second deformation mode is greater than that in the first deformation mode. In this regard, in this embodiment, the second portion 32 extends in the X-direction, which further reduces the deformation in the second deformation mode. This ensures the required electrical conductivity and heat dissipation in the electrode 30, while also suppressing changes in the relative positions of the multiple core layers 21b and, consequently, suppressing a decrease in the optical coupling efficiency between the core layers 21b and the waveguides to which they correspond. Width W1 is an example of the first width, and width W2 is an example of the second width.

[0064] In addition, if Figure 2 As shown, in this embodiment, the second portion 32 extends in the X direction at a position overlapping with the core layer 21b in the Z direction. This allows for more efficient power supply from the electrode 30 to the core layer 21b, compared to a case where the electrode 30 is offset from the position overlapping with the core layer 21b in the Z direction.

[0065] In addition, if Figure 2 As shown, in this embodiment, when viewed in the direction opposite to the Z direction, the second portion 32 is offset in the Y direction or in the direction opposite to the Y direction relative to the centerline C located at the center of the electrode 30 in the X direction. When utilizing the Z-direction end surface of the first portion 31 as an area for wiring (not shown) for wire bonding or for contact with a probe to confirm height position, it is preferable to ensure a larger size for the first portion 31. In this regard, in this embodiment, the second portion 32 is provided at a position offset in the Y direction relative to the centerline C of the electrode 30. This allows for a larger Z-direction end surface of at least one first portion 31 compared to a case where the second portion 32 is provided at a position overlapping the centerline C of the electrode 30.

[0066] As described above, the electrode 30 includes the first layer 30a and the second layer 30b. The first layer 30a constitutes the first portion 31 and a portion of the second portion 32, and the second layer 30b constitutes the portion of the second portion 32 on the opposite side of the first layer 30a from the waveguide structure 20. According to this embodiment, the electrode 30 having the first portion 31 and the second portion 32 of different thicknesses can be formed using a relatively simple process.

[0067] As described above, according to the present embodiment, a new and improved semiconductor optical device 100 can be obtained that can suppress an increase in resistance in the electrode 30 and a decrease in heat dissipation of the electrode 30 while suppressing thermal deformation, for example.

[0068] [Second embodiment]

[0069] Figure 3 This is a top view of a semiconductor optical device 100B (100) according to the second embodiment. In this embodiment, although the structure of the functional portion 101 itself is different from that of the first embodiment, the functional portion 101 has the same waveguide structure 20 and electrodes 30 and 40 (see Figure 1 ) and operates by using a semiconductor light-emitting element such as a semiconductor laser. These semiconductor light-emitting elements output light from one end of the core layer 21b. That is, the semiconductor optical device 100B of this embodiment is configured as a semiconductor light-emitting element array. In the case where the semiconductor light-emitting element is a semiconductor laser, each functional part 101 has a reflective film that constitutes a laser resonator. In addition, in the case where the semiconductor light-emitting element is a DFB type semiconductor laser, each functional part 101 also has a diffraction grating layer for determining the laser oscillation wavelength. In this embodiment, the electrode 30 also has the same structure as the first embodiment. Therefore, according to this embodiment, the same effect as the first embodiment can be obtained.

[0070] [Third embodiment]

[0071] Figure 4 1 is a top view of a semiconductor optical device 100C (100) according to the third embodiment. Figure 5 yes Figure 4 In this embodiment, the two functional units 101 have the same structure as the first embodiment and operate as semiconductor optical amplifiers, and the waveguide structures 20 of the two functional units 101 are optically connected to each other via a folded waveguide structure 50 having a core layer 21b that functions as a passive waveguide. Figure 5 As shown, the folded-back waveguide structure 50 has a high-top structure. With this structure, the semiconductor optical device 100C as a whole functions as a semiconductor optical amplifier. This semiconductor optical amplifier amplifies light input from one end of the core layer 21b of one functional portion 101 and outputs it from one end of the core layer 21b of another functional portion 101. In this embodiment, the electrode 30 also has the same structure as in the first embodiment. Therefore, this embodiment also achieves the same effects as in the first embodiment.

[0072] [Fourth embodiment]

[0073] Figure 6This is a top view of a semiconductor optical device 100D (100) according to a fourth embodiment. In this embodiment, semiconductor optical amplifiers, similar to those in the third embodiment, are arranged in the Y direction via grooves 100a. In other words, the semiconductor optical device 100D according to this embodiment constitutes a semiconductor optical amplifier array. In this embodiment, the electrode 30 also has the same structure as in the first embodiment. Therefore, this embodiment also achieves the same effects as in the first embodiment.

[0074] [Fifth embodiment]

[0075] Figure 7 This is a top view of a semiconductor optical device 100E (100) according to the fifth embodiment. The semiconductor optical device 100E of this embodiment includes two functional portions 101 and a folded waveguide structure 50 similar to the semiconductor optical device 100C of the third embodiment, and operates similarly to the semiconductor optical device 100C. However, the structure of the electrode 30 in this embodiment differs from that in the third embodiment.

[0076] Specifically, the second portion 32 includes an active portion 32a, a pad portion 32b, and an extension portion 32c. The active portion 32a overlaps with the core layer 21b in the Z direction in each functional portion 101, supplying an electrode to the mesa 21. The pad portion 32b is located on the opposite side of the folded waveguide structure 50 from the two functional portions 101. A power supply member, such as a bonding wire, is bonded to the pad portion 32b. The extension portion 32c extends in the X direction between the active portion 32a and the pad portion 32b. The pad portion 32b and the extension portion 32c are common to multiple active portions 32a.

[0077] In this embodiment, the second portion 32 extends longer in the X direction than the first portion 31. According to this embodiment, as in the first embodiment described above, the required electrical conductivity and heat dissipation of the electrode 30 can be ensured, and the deformation amount in the second deformation mode, in which the position of each layer in the Z direction changes as it moves in the Y direction, can be further reduced. Therefore, changes in the relative positions of the multiple core layers 21b can be suppressed, and further, a decrease in the optical coupling efficiency between the core layer 21b and the waveguide corresponding to the core layer 21b can be suppressed.

[0078] Figure 8 yes Figure 7 Sectional view VIII-VIII of Figure 8 As shown, in this embodiment, the second portion 32 (the extension portion 32c thereof), which includes the first layer 30a and the second layer 30b and is thicker than the first portion 31, spans the height difference of the folded-back waveguide structure 50 having a high mesa structure. This structure prevents disconnection of the electrode 30 at the spanned position and suppresses an increase in resistance.

[0079] [Sixth embodiment]

[0080] Figure 9 is a cross-sectional view of a semiconductor optical device 100F (100) according to the sixth embodiment. Figure 10 This is a top view of the semiconductor optical device 100F (100). Figure 9 yes Figure 10 IX-IX cross-sectional view. The semiconductor optical device 100F of this embodiment includes the same two functional units 101 and the folded waveguide structure 50 as the semiconductor optical device 100C of the third embodiment, and operates in the same manner as the semiconductor optical device 100C. However, in this embodiment, the structure of the electrode 40F (40) serving as the N-side electrode differs from that of the first to fifth embodiments.

[0081] Specifically, in the semiconductor optical device 100F, a recess 100b is provided on the opposite side of the two functional parts 101 across the groove 100a. The recess 100b is recessed in the opposite direction of the Z direction and reaches the substrate 10. The electrode 40F is provided along the bottom surface 100b1 and the side surface 100b2 of the recess 100b.

[0082] Like electrode 30, electrode 40F includes a first layer 40a and a second layer 40b stacked on first layer 40a. This configuration includes a third portion 41 consisting solely of first layer 40a, and a fourth portion 42 comprising first layer 40a and second layer 40b and thicker than third portion 41. Furthermore, an opening 23b is provided in insulating layer 23 covering recess 100b at a position overlapping bottom surface 100b1. First layer 40a is in contact with substrate 10 via opening 23b.

[0083] In addition, if Figure 10 As shown, the fourth portion 42 of the electrode 40F includes an active portion 42a, a pad portion 42b, and an extension portion 42c. The active portion 42a contacts the substrate 10 at the bottom surface 100b1 of the recess 100b, supplying an electrode to the substrate 10. The pad portion 42b is separated from the active portion 42a in the direction opposite to the X direction. A power supply member such as a bonding wire is connected to the pad portion 42b. The extension portion 42c extends in the X direction between the active portion 42a and the pad portion 42b.

[0084] Furthermore, in the electrode 40F, the fourth portion 42 extends longer in the X direction than the third portion 41. With this structure, as in the first embodiment described above, the desired electrical conductivity and heat dissipation properties of the electrode 40F can be ensured, and the amount of deformation in the second deformation mode, in which the position of each layer in the Z direction changes as it moves in the Y direction, can be further reduced. This suppresses changes in the relative positions of the multiple core layers 21b, and further suppresses a decrease in the optical coupling efficiency between the core layers 21b and the waveguides corresponding to the core layers 21b.

[0085] In addition, if Figure 9 、 Figure 10 As shown, in this embodiment, the fourth portion 42, which is thicker than the third portion 41, spans the height difference of the recess 100b. This structure can prevent disconnection of the electrode 40 at the spanning position and suppress an increase in resistance.

[0086] [Seventh embodiment]

[0087] Figure 11 This is a top view of an optical integrated component 300 according to the seventh embodiment. The optical integrated component 300 includes the semiconductor optical device 100C (100) according to the third embodiment and an optical functional element 200. The optical functional element 200 may also be called a silicon platform.

[0088] The end face 100c in the X direction of the semiconductor optical device 100C and the end face 200a in the opposite direction of the X direction of the optical functional element 200 face each other. Here, the semiconductor optical device 100C has the structure of the third embodiment. Therefore, in the semiconductor optical device 100C (100), similar to the third embodiment and the first embodiment, for example, the following effects can be obtained: thermal deformation can be suppressed, and the increase in resistance in the electrode 30 and the reduction in heat dissipation of the electrode 30 can be suppressed. Therefore, in the optical integrated element 300 having the semiconductor optical device 100C (100), the ends of the core layer 21b in the X direction at two locations on the end face 100c and the ends of the core layer 200b (waveguide) in the opposite direction of the X direction at two locations on the end face 200a can be positioned with higher precision, for example, an effect of further reducing the coupling loss between the semiconductor optical device 100 and the optical functional element 200 can be obtained. In addition, the constituent material of the optical functional element 200 is not limited to silicon, and may also be other semiconductors or glass.

[0089] While the embodiments of the present invention have been described above, these embodiments are merely examples and are not intended to limit the scope of the invention. The embodiments described above can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, various structural and shape specifications (such as structure, type, orientation, form, size, length, width, thickness, height, number, placement, position, and material) can be appropriately modified for implementation.

[0090] Industrial applicability

[0091] The present invention can be used in semiconductor optical devices and optical integrated components.

[0092] -Description of Reference Numerals-

[0093] 10…Substrate

[0094] 20, 20-1, 20-2… waveguide structure

[0095] 21…table

[0096] 21a…Clad layer (first cladding layer)

[0097] 21b…core layer

[0098] 21c…Clad layer (second cladding layer)

[0099] 22a…Current blocking layer

[0100] 22b…current blocking layer

[0101] 22c…Clad layer (third cladding layer)

[0102] 23…Insulation layer

[0103] 23a…Opening

[0104] 23b…opening

[0105] 30…Electrode (first electrode, electrode pair)

[0106] 30a…first floor

[0107] 30b…Second floor

[0108] 31…the first part

[0109] 32…Second part

[0110] 32a…action part

[0111] 32b…pad part

[0112] 32c…Extension

[0113] 40, 40A, 40F…Electrodes (second electrode, electrode pair)

[0114] 40a…first floor

[0115] 40b…second floor

[0116] 41…the third part

[0117] 42…the fourth part

[0118] 42a…action part

[0119] 42b…pad

[0120] 42c…Extension

[0121] 50…Fold-back waveguide structure

[0122] 100, 100A~100F…semiconductor optical devices

[0123] 100a...slot

[0124] 100b…concave part

[0125] 100b1…bottom

[0126] 100b2…side

[0127] 100c…end face

[0128] 101…Function Department

[0129] 200... optical functional components (different parts)

[0130] 200a…end face

[0131] 200b…core layer (waveguide)

[0132] 300...Optical integrated components

[0133] C…Center line (center)

[0134] W1…Width (first width)

[0135] W2…Width (second width)

[0136] X…direction (second direction)

[0137] Y…direction (third direction)

[0138] Z…direction (first direction).

Claims

1. A semiconductor optical device, characterized in that: have: a substrate extending crosswise to the first direction; a plurality of waveguide structures, each having a first cladding layer, a core layer, and a second cladding layer stacked in the first direction on the substrate, extending in a second direction intersecting the first direction and guiding light in the second direction or a direction opposite to the second direction, and being separated from each other in a third direction intersecting the first and second directions; as well as The first electrode is provided on the side opposite to the substrate with respect to each of the waveguide structures and has a first portion and a second portion thicker than the first portion in the first direction.

2. The semiconductor optical device according to claim 1, wherein The first electrode includes a first electrode extending along the second direction with a first width, and the second portion extending along the second direction with a second width narrower than the first width at least partially.

3. The semiconductor optical device according to claim 2, wherein The first electrode includes a first electrode extending along the second direction with a first width, wherein the second portion at least partially extends along the second direction with a second width narrower than the first width, and the first portion and the second portion are at least partially aligned along the third direction. The semiconductor optical device according to claim 2 , wherein: The first electrode includes a first electrode extending in the second direction with a first width, wherein the second portion extends in the second direction with a second width narrower than the first width at least partially at a position aligned with the core layer in the first direction. The semiconductor optical device according to claim 2 , wherein: As the first electrode, there is provided a first electrode extending along the second direction with a first width, and the second portion extending along the second direction with a second width narrower than the first width at a position deviated toward the third direction or the opposite direction of the third direction relative to the center of the first electrode in the third direction. The semiconductor optical device according to claim 2 , wherein: As the first electrode, a first electrode is provided, which extends along the second direction and in which the second portion extends longer than the first portion in the second direction.

7. The semiconductor optical device according to claim 1, wherein The first electrode includes a first layer constituting the first portion and a portion of the second portion, and a second layer constituting a portion of the second portion on the opposite side of the first layer from the waveguide structure. The semiconductor optical device according to claim 1 , wherein: As the waveguide structure, a waveguide structure constituting an active waveguide is provided.

9. The semiconductor optical device according to claim 1, wherein As the waveguide structure, two waveguide structures optically connected via a folded waveguide structure are provided.

10. The semiconductor optical device according to claim 9, wherein The folded-back waveguide structure constitutes a passive waveguide. The semiconductor optical device according to claim 9 , wherein: The semiconductor optical device includes a plurality of waveguide structure components, each of which includes the folded waveguide structure and two waveguide structures optically connected via the folded waveguide structure.

12. The semiconductor optical device according to claim 1, wherein As the waveguide structure, two waveguide structures are provided, which are arranged in the third direction via a groove extending in the second direction.

13. The semiconductor optical device according to claim 1, wherein The semiconductor optical device is provided with a recessed portion that is recessed in a direction opposite to the first direction and reaches the substrate. The semiconductor optical device includes a second electrode provided at least partially in the recess. The semiconductor optical device according to claim 13 , wherein: The second electrode has a third portion and a fourth portion that is thicker than the third portion.

15. The semiconductor optical device according to claim 14, wherein The fourth portion has an extension portion extending in the first direction along a side surface of the recessed portion.

16. The semiconductor optical device according to claim 1, wherein The semiconductor optical device includes a semiconductor optical amplifier having the waveguide structure and an electrode pair provided corresponding to the waveguide structure.

17. The semiconductor optical device according to claim 1, wherein The semiconductor optical device includes a semiconductor light emitting element having the waveguide structure and an electrode pair provided corresponding to the waveguide structure.

18. An optical integrated component, characterized in that: Integrated with: The semiconductor optical device according to any one of claims 1 to 17; and An optical functional element includes a waveguide optically connected to the waveguide structure of the semiconductor optical device.

Images