Optical semiconductor element and method for manufacturing optical semiconductor element

Abstract

The optical semiconductor element includes a buried layer disposed between a first mesa structure of the light-emitting portion and a second mesa structure of the light-receiving portion, and disposed at two locations: one adjacent to the first mesa structure and the other adjacent to the second mesa structure in a third direction, and the other adjacent to the first mesa structure and the other in the opposite direction. Regarding the interface between the second mesa structure and the buried layer between the second mesa structure and the light-emitting portion, within the light-receiving range of the light emitted from the light-emitting portion, there is an inclined portion in which the cut line in the cross section intersecting the first direction is inclined at a predetermined angle relative to the second direction. The first direction is the crystal orientation [100] direction, the second direction is the crystal orientation [0-11] direction or the crystal orientation [01-1] direction, the third direction is the crystal orientation [0-1-1] direction or the crystal orientation [011] direction, and the absolute value of the predetermined angle of the acute angle is 35°±30°.

Description

Technical Field

[0001] This invention relates to optical semiconductor devices and methods for manufacturing optical semiconductor devices. Background Technology

[0002] Previously, there were known light semiconductor devices that integrated a light-emitting part, such as a semiconductor laser, and a light-receiving part, such as a photodiode (for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 3-89577 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In such optical semiconductor devices, if light emitted from the light-emitting part is reflected back to the light-emitting part by the light-receiving part, it may adversely affect the output characteristics of the light-emitting part. In addition, if the active layer of the light-emitting part and the absorption layer of the light-receiving part are exposed, they may deteriorate easily.

[0008] Therefore, one of the objectives of this invention is to provide, for example, a novel optical semiconductor device and a method for manufacturing such a device that can suppress reflected light from the light-receiving portion from returning to the light-emitting portion and suppress the deterioration of the active layer and the absorption layer.

[0009] Methods for solving problems

[0010] The optical semiconductor element of the present invention includes, for example: a light-emitting portion having a first mesa structure comprising a first cladding layer, an active layer, and a second cladding layer stacked in a first direction, and emitting light in a second direction intersecting the first direction; a light-receiving portion having a second mesa structure comprising the first cladding layer stacked in the first direction, an absorption layer made of the same material as the active layer, and a second cladding layer, and being separated from the first mesa structure in the second direction, and receiving light emitted from the light-emitting portion; and a buried layer disposed between the first mesa structure and the second mesa structure, and disposed at a position adjacent to the first mesa structure and the second mesa structure respectively in a third direction intersecting the first direction and the second direction. The third direction is located at positions adjacent to the first mesa structure and the second mesa structure respectively, and includes a current blocking layer. Regarding the interface between the second mesa structure and the embedded layer between the second mesa structure and the light-emitting part, within the light-receiving range of the light emitted from the light-emitting part, there is an inclined portion with a cut line in a cross section intersecting the first direction inclined at a predetermined angle relative to the second direction. The first direction is a crystal orientation

[100] direction, the second direction is a crystal orientation [0-11] direction or a crystal orientation [01-1] direction, the third direction is a crystal orientation [0-1-1] direction or a crystal orientation

[011] direction, and the absolute value of the predetermined angle of the acute angle is 35°±30°.

[0011] In the optical semiconductor element, a trench may also be provided between the light-emitting part and the light-receiving part, the trench being open in the first direction and extending in a fourth direction that intersects the first direction and the second direction.

[0012] In the optical semiconductor element, the fourth direction may also be tilted relative to the third direction.

[0013] In the optical semiconductor element, the absolute value of the angle difference between the acute angles of the fourth direction and the third direction may be greater than 0° and less than 18°.

[0014] In the optical semiconductor element, multiple pairs of light-emitting portions and light-receiving portions that receive light emitted from the light-emitting portions may be arranged at intervals in the third direction.

[0015] In the optical semiconductor element, the interface may also have a ridge portion protruding in the opposite direction to the second direction or a valley portion recessed in the opposite direction to the second direction, wherein the ridge portion or the valley portion is offset from the center of the optical axis of the light emitted from the light-emitting part and reaching the interface in the third direction or the opposite direction to the third direction.

[0016] The method for manufacturing the optical semiconductor element of the present invention includes, for example, a light-emitting portion having a first mesa structure comprising a first cladding layer, an active layer, and a second cladding layer stacked in a first direction, and emitting light in a second direction intersecting the first direction; a light-receiving portion having a second mesa structure comprising the first cladding layer stacked in the first direction, an absorption layer made of the same material as the active layer, and a second cladding layer, and being separated from the first mesa structure in the second direction, and receiving light emitted from the light-emitting portion; and a buried layer disposed between the first mesa structure and the second mesa structure, and disposed at positions adjacent to the first mesa structure and the second mesa structure respectively in a third direction intersecting the first and second directions, and at positions adjacent to the first mesa structure and the second mesa structure respectively in the opposite direction of the third direction, and comprising a current-blocking layer, wherein the light emitted from the light-emitting portion is received at the interface between the second mesa structure and the buried layer between the second mesa structure and the light-emitting portion. Within the light-receiving range of the output light, there is an inclined portion with a cut-off line in a cross section intersecting the first direction inclined at a predetermined angle relative to the second direction. The first direction is a crystal orientation

[100] direction, the second direction is a crystal orientation [0-11] direction or a crystal orientation [01-1] direction, and the third direction is a crystal orientation [0-1-1] direction or a crystal orientation

[011] direction. The absolute value of the predetermined angle is 35°±30°. The manufacturing method of the optical semiconductor element includes: a step of forming a laminate by stacking the first cladding layer, the active layer, the absorber layer, and the second cladding layer on a substrate; a step of forming the first mesa structure and the second mesa structure by etching the laminate; and a step of forming the buried layer by filling the recess between the first mesa structure and the second mesa structure, and at a position adjacent to the first mesa structure and the second mesa structure in the opposite direction of the third direction.

[0017] Invention Effects

[0018] According to the present invention, a novel optical semiconductor device and a method for manufacturing the optical semiconductor device can be provided, for example, to suppress reflected light from the light-receiving part from returning to the light-emitting part and to suppress the deterioration of the active layer and the absorption layer. Attached Figure Description

[0019] Figure 1 This is an illustrative and schematic perspective view of the optical semiconductor element according to the first embodiment.

[0020] Figure 2This is an illustrative and schematic top view of the optical semiconductor element according to the first embodiment.

[0021] Figure 3 yes Figure 2 Sectional view III-III.

[0022] Figure 4 yes Figure 2 Sectional view IV-IV.

[0023] Figure 5 yes Figure 2 VV sectional view.

[0024] Figure 6 This is a flowchart illustrating an example of the steps in a method for manufacturing an optical semiconductor element according to an embodiment.

[0025] Figure 7 This is an illustrative and schematic top view of the optical semiconductor element according to the second embodiment.

[0026] Figure 8 This is an illustrative and schematic top view of the optical semiconductor element according to the third embodiment.

[0027] Figure 9 This is an illustrative and schematic perspective view of the optical semiconductor element according to the fourth embodiment.

[0028] Figure 10 This is an illustrative and schematic top view of the optical semiconductor element according to the fifth embodiment.

[0029] Figure 11 This is an illustrative and schematic top view of the optical semiconductor element according to the sixth embodiment.

[0030] Figure 12 The optical semiconductor element of the seventh embodiment and Figure 3 An illustrative and schematic sectional view at the same location.

[0031] Figure 13 This is an illustrative and schematic perspective view of the optical semiconductor element according to the eighth embodiment.

[0032] Figure 14 This is an illustrative and schematic top view of a photonic semiconductor element, which is a first variation of the embodiment.

[0033] Figure 15 This is an illustrative and schematic top view of a photonic semiconductor element, which is a second variation of the embodiment.

[0034] Figure 16 This is an illustrative and schematic perspective view of a light semiconductor element according to a third variation of the embodiment.

[0035] Figure 17 This is an illustrative and schematic cross-sectional view of a mounting structure in which the optical semiconductor element of the seventh embodiment is mounted. Detailed Implementation

[0036] Hereinafter, exemplary embodiments and modifications of the present invention are disclosed. The structures of the embodiments and modifications shown below, as well as the effects and results (effects) brought about by such structures, are examples. The present invention can also be implemented with structures other than those disclosed in the embodiments and modifications below. In addition, according to the present invention, at least one of various effects (including derived effects) obtained by the structure can be obtained.

[0037] The various embodiments and modifications shown below have the same structure. Therefore, based on the structure of each embodiment and modification, the same function and effect based on the same structure can be obtained. Furthermore, the same reference numerals will be used to label these identical structures below, and repeated descriptions will sometimes be omitted.

[0038] In this specification, ordinal numbers are applied for the purpose of distinguishing directions, locations, etc., and do not indicate priority, order, or limit the number of ordinal numbers.

[0039] In the diagrams, arrow X represents the X-direction, arrow Y represents the Y-direction, and arrow Z represents the Z-direction. The X, Y, and Z directions intersect and are orthogonal to each other. It should be noted that the X-direction can also be called the extension direction, and the Y-direction can also be called the width direction. Additionally, the Z-direction can also be called the height direction, the stacking direction, or the upward direction.

[0040] In addition, each figure is a schematic diagram for illustrative purposes, and the scale and ratio of each figure may not be consistent with the actual object.

[0041] [First Implementation Method]

[0042] [Structure of Optical Semiconductor Devices]

[0043] Figure 1 This is a perspective view of the optical semiconductor element 100A (100) according to the first embodiment. Figure 2 This is a top view of the 100A optoelectronic semiconductor device.

[0044] like Figure 1 As shown, the optical semiconductor element 100A includes a laminate 10 having layers made of semiconductors stacked on top of each other. The laminate 10 is made of semiconductor crystals. Figure 1 , 2As shown, a light-emitting part 20 and a light-receiving part 30A (30) are provided in the laminate 10. The light-emitting part 20 is a semiconductor laser element, located inside the laminate 10, and outputs detection light (laser) towards the light-receiving part 30 in the X direction. It should be noted that the light-emitting part 20 also outputs light (laser) in the opposite direction to the X direction. The light-receiving part 30 is a photodiode, which receives the light output from the light-emitting part 20 and outputs an output current corresponding to the amount of light received. The light-receiving part 30 is separated from the light-emitting part 20 in the X direction.

[0045] The laminate 10 has a generally rectangular parallelepiped shape and extends along the X direction with a specified width in the Y direction and a specified height in the Z direction.

[0046] Electrodes 18a and 18b are formed on the upper surface 10a of the Z-direction end of the laminate 10. Electrodes 18a and 18b are P electrodes with the same structure, for example, having a laminate structure containing Au, AuZn, Pt, etc. Electrode 18a is disposed corresponding to the light-emitting part 20, and electrode 18b is disposed corresponding to the light-receiving part 30. Electrode 18a is disposed separately from the active layer 17a in the Z-direction, and electrode 18b is disposed separately from the absorber layer 17b in the Z-direction.

[0047] Furthermore, electrodes 19a and 19b are formed on the lower surface 10b of the end of the laminate 10 located in the opposite direction to the Z direction. Electrodes 19a and 19b are N electrodes with the same structure, for example, having a laminate structure containing AuGe, Ni, Au, etc. Electrode 19a is provided corresponding to the light-emitting part 20, and electrode 19b is provided corresponding to the light-receiving part 30. It should be noted that electrodes 19a and 19b can also be integrated into a single electrode.

[0048] The laminate 10 includes a substrate 11. The substrate 11 has a quadrilateral shape intersecting the Z direction and is plate-shaped, extending along the X direction with a predetermined width in the Y direction and a predetermined height in the Z direction. The substrate 11 is made of, for example, n-InP.

[0049] A lower cladding layer 12, a lower barrier layer 13, an upper barrier layer 14, an upper cladding layer 15, a contact layer 16, an active layer 17a, and an absorber layer 17b are stacked on the substrate 11 (see reference). Figure 4 )wait.

[0050] Figure 3 yes Figure 2 Sectional view III-III. Figure 3 This is a cross-sectional view, intersecting the X direction, of the portion of the laminate 10 in which the light-emitting portion 20 is formed. The laminate 10 has within the area where the light-emitting portion 20 is formed... Figure 3 The cross-sectional shape.

[0051] At this location, approximately at the center in the Y direction, a lower cladding layer 12, an active layer 17a, an upper cladding layer 15, and a contact layer 16 are sequentially stacked on the substrate 11. The active layer 17a is sandwiched between the lower cladding layer 12 and the upper cladding layer 15 in the Z direction. This structure forms a mesa structure 20a, which is the functional part of the light-emitting part 20. The lower cladding layer 12 is made of, for example, n-InP. The upper cladding layer 15 is made of, for example, p-InP. The contact layer 16 is made of, for example, InGaAsP. In addition, the active layer 17a has, for example, a multilayer structure with InGaAsP as the main component. The lower cladding layer 12 is an example of a first cladding layer, and the upper cladding layer 15 is an example of a second cladding layer. In addition, the mesa structure 20a is an example of a first mesa structure.

[0052] At positions on substrate 11 adjacent to mesa structure 20a in the Y direction and adjacent to mesa structure 20a in the opposite Y direction, a lower cladding layer 12, a lower barrier layer 13, an upper barrier layer 14, an upper cladding layer 15, and a contact layer 16 are sequentially stacked. The lower barrier layer 13 is made of p-InP, for example, and the upper barrier layer 14 is made of n-InP, for example. The lower barrier layer 13 and the upper barrier layer 14 constitute a buried layer 41, which is an example of a current blocking layer.

[0053] Figure 4 yes Figure 2 Sectional view IV-IV. Figure 4 This is a cross-sectional view of the portion of the laminate 10 that forms the light-receiving portion 30, intersecting the X direction. The laminate 10 has, within the area where the light-receiving portion 30 is formed, a portion that... Figure 4 The same cross-sectional shape. However, the width of the absorbing layer 17b in the Y direction gradually increases as it moves toward the X direction.

[0054] At this location, approximately at the center in the Y direction, a lower cladding layer 12, an absorption layer 17b, an upper cladding layer 15, and a contact layer 16 are sequentially stacked on the substrate 11. The absorption layer 17b is sandwiched between the lower cladding layer 12 and the upper cladding layer 15 in the Z direction. This structure constitutes a mesa structure 30a, which forms the functional part of the light-receiving section 30. The absorption layer 17b is made of the same material as the active layer 17a. The mesa structure 30a is an example of a second mesa structure.

[0055] At positions on the substrate 11 adjacent to the mesa structure 30a in the Y direction and adjacent to the mesa structure 30a in the opposite direction of the Y direction, a lower cladding layer 12, a lower barrier layer 13, an upper barrier layer 14, an upper cladding layer 15, and a contact layer 16 are sequentially stacked. In these locations, the lower barrier layer 13 and the upper barrier layer 14 also constitute a buried layer 41, which is an example of a current blocking layer.

[0056] Figure 5 yes Figure 2 VV sectional view. Figure 5 This is a cross-sectional view intersecting the Y direction of the portion of the laminate 10 where the light-receiving portion 30 is formed. The laminate 10 has within the area forming the mesa structure 20a and the mesa structure 30a... Figure 5 The cross-sectional shape. However, depending on the position of the cross-section in the Y direction, the position of the end of the absorber layer 17b in the opposite direction in the X direction is different.

[0057] The structure of the light-emitting part 20 and the light-receiving part 30 Figure 3 , 4 The structure shown is the same. An embedded layer 42 having the same stacked structure as the embedded layer 41 is provided between the mesa structure 20a of the light-emitting part 20 and the mesa structure 30a of the light-receiving part 30. Light emitted from the active layer 17a of the light-emitting part 20 passes through the embedded layer 42 and is received by the absorption layer 17b of the light-receiving part 30.

[0058] Figure 2 The double-dotted line (VLa) is the cut line in the Z-direction section of the interface 20b between the platform structure 20a (active layer 17a and lower cladding 12) and the embedded layers 41 and 42. Additionally, Figure 2 The double-dotted line (VLb) in the figure is the cut-off line in the cross section of the interface 30b between the mesa structure 30a (absorbing layer 17b and lower cladding 12) and the embedded layers 41 and 42, intersecting the Z-direction. It should be noted that the cut-off lines VLa and VLb shown in each figure are cut-off lines in the cross section passing approximately at the center of the active layer 17a or the absorbing layer 17b in the Z-direction, but the cut-off lines of the cross section at any position in the Z-direction are approximately parallel to the cut-off lines VLa and VLb.

[0059] from Figure 2 As can be seen, in this embodiment, the cut line VLb of the interface 30b between the mesa structure 30a of the light-receiving part 30 and the embedded layer 42, except for the ridge portion 30c protruding in the opposite direction to the X direction (the direction between the X and Z directions), is inclined at a predetermined angle (angle difference θ1) relative to the X direction. That is, in this structure, the interface 30b does not face the opposite direction to the X direction. Therefore, the reflected light from the portion of the interface 30b other than the ridge portion 30c of the light emitted from the active layer 17a of the light-emitting part 20 does not propagate in the opposite direction to the X direction and does not return to the active layer 17a of the light-emitting part 20. Therefore, according to this structure, it is possible to suppress the adverse effects of reflected light at the interface 30b on the light-emitting characteristics of the light-emitting part 20. The portion of the interface 30b other than the ridge portion 30c is an example of an inclined portion.

[0060] [Manufacturing Method]

[0061] Figure 6This is a flowchart illustrating an example of the steps in a method for manufacturing an optical semiconductor element 100. For example... Figure 6 As shown, firstly, layers constituting mesa structures 20a and 30a, namely the lower cladding layer 12, the active layer 17a, the absorber layer 17b, and a portion (lower part) of the upper cladding layer 15 (S1), are stacked on the substrate 11. As described above, the active layer 17a and the absorber layer 17b are made of the same material, and therefore can be stacked in the same process.

[0062] Next, the laminate formed in S1 is subjected to, for example, wet etching, thereby forming mesa structures 20a and 30a (S2). Specifically, with the upper ends (Z-direction ends) of the mesa structures 20a and 30a masked by the dielectric layer, etching is selectively performed in the opposite direction of the Z-direction to remove the portions surrounding the mesa structures 20a and 30a, thereby forming mesa structures 20a and 30a of a predetermined shape. That is, in the laminate, recesses are formed around the mesa structures 20a and 30a. The portions surrounding the mesa structures 20a and 30a refer to the portions between the mesa structures 20a and 30a, and adjacent to each mesa structure 20a and 30a in the Y-direction and the opposite direction of the Y-direction. Figures 3-5 The double-dotted line and the aforementioned interfaces 20b and 30b are at least a portion of the side surfaces of the platform structures 20a and 30a at the end of S2.

[0063] Next, layers 41 and 42, namely the lower barrier layer 13 and the upper barrier layer 14, are stacked to fill the recesses formed around the mesa structures 20a and 30a (S3). In S3, the embedded layers 41 and 42 are formed by epitaxial growth while the upper ends (ends in the Z direction) of the mesa structures 20a and 30a are masked by the dielectric layer. Through this S3, the recesses around the mesa structures 20a and 30a are filled by the embedded layers 41 and 42.

[0064] Here, when the materials constituting the mesa structures 20a and 30a and the buried layers 41 and 42 are made of, for example, a group III-V compound semiconductor with a zincblende structure, abnormal growth occurs on the interfaces 20b and 30b depending on their orientation (normal direction). For example, voids may sometimes form, unwanted protrusions may form, or warping may occur. This is because the coupling force between crystals varies depending on the direction. In particular, if voids, protrusions, or warping occur at the interface 30b of the light-receiving portion 30, it is possible to cause adverse conditions such as reduced coupling efficiency of light from the light-emitting portion 20 to the light-receiving portion 30, increased dark current, and light from the light-emitting portion 20 being reflected in an unintended direction at the interface 30b. In addition, along with this, the detection accuracy in the light-receiving portion 30 may decrease, or individual differences in the detection characteristics of the light-receiving portion 30 may occur. Therefore, the inventors have conducted in-depth research through repeated experiments and simulations, and the results are as follows: Figure 2 As shown, the Z direction is set as the crystal orientation

[100] direction, the X direction is set as the crystal orientation [0-11] direction, and the Y direction is set as the crystal orientation [0-1-1] direction. Based on this, it was confirmed that by setting the absolute value of the angle difference θ1 between the severance line VLb and the X direction at interface 30b to 35°±30°, abnormal growth does not occur at interface 30b, and the generation of voids, protrusions, and warping can be suppressed. Furthermore, from this perspective, it was confirmed that the absolute value of this angle difference θ1 is more preferably 35°±10°.

[0065] Next, the upper surface of the laminate formed in S3 is smoothed by etching, for example (S4), and an upper structure, such as a portion of the upper cladding 15 (the upper part, the portion above the buried layers 41 and 42) and a contact layer 16 are formed on the upper surface (S5). Then, electrodes 18a, 18b, 19a, and 19b are formed (S6).

[0066] As explained above, the light-emitting portion 20 and the light-receiving portion 30 of the optical semiconductor element 100 according to this embodiment have a so-called dual heterogeneous structure, which improves light containment and further enhances the laser oscillation efficiency of the light-emitting portion 20 and the photoelectric conversion efficiency of the light-receiving portion 30. Furthermore, the active layer 17a and the absorption layer 17b are covered by the embedded layer 42 and are not exposed, thus suppressing the degradation of the active layer 17a and the absorption layer 17b. Additionally, if the aforementioned laminate or laminate 10 is etched to expose the active layer 17a and the absorption layer 17b, the exposed surfaces become rough due to the etching, potentially adversely affecting the optical properties of the light-emitting portion 20 or the light-receiving portion 30. In this embodiment, etching to expose the active layer 17a and the absorption layer 17b is not performed, thus suppressing the increase in surface roughness of the end face.

[0067] Furthermore, according to this embodiment, as described above, in the inclined portion of the interface 30b other than the ridge portion 30c, the cut line VLb in the cross section of the interface 30b intersecting the Z direction is inclined at a predetermined angle (angle difference θ1) relative to the X direction. Therefore, it is possible to suppress the reflected light from the light-emitting portion 20 from the interface 30b from returning to the light-emitting portion 20. It should be noted that in this embodiment, the entire portion of the interface 30b other than the ridge portion 30c is an inclined portion, but this inclined portion only needs to be provided within the light-receiving range of the light from the light-emitting portion 20 in the interface 30b.

[0068] Furthermore, according to this embodiment, as described above, based on setting the Z direction as the crystal orientation

[100] direction, the X direction as the crystal orientation [0-11] direction, and the Y direction as the crystal orientation [0-1-1] direction, the absolute value of the angle difference θ1 between the cutting line VLb and the X direction at the interface 30b is set to 35°±30°. This suppresses the generation of voids, protrusions, and warping caused by abnormal growth at the interface 30b, thereby suppressing adverse conditions such as reduced detection accuracy of the light-receiving part 30 and individual differences in detection characteristics.

[0069] [Second and Third Embodiments]

[0070] Figure 7 This is a top view of the optical semiconductor element 100B (100) according to the second embodiment. Additionally, Figure 8 This is a top view of the optical semiconductor element 100C (100) of the third embodiment. The optical semiconductor element 100B of the second embodiment and the optical semiconductor element 100C of the third embodiment also have the same structure as the optical semiconductor element 100A of the first embodiment, and can obtain the same effect based on the same structure.

[0071] However, Figure 7 , 8 and Figure 2 A comparison reveals that the structures of the light-receiving parts 30B and 30C (30) in the second and third embodiments differ from the structure of the light-receiving part 30A (30) in the first embodiment. For example... Figure 8 As shown, in the third embodiment, the interface 30b of the light-receiving portion 30C has a valley line portion 30d that is recessed in the direction between the opposite directions of the X and Z directions, instead of the ridge portion 30c. That is, the area of ​​the interface 30b other than the valley line portion 30d becomes an inclined portion. In addition, as Figure 7As shown, the interface 30b of the light-receiving portion 30B in the second embodiment does not have the ridge portion 30c as in the first embodiment or the valley portion 30d as in the third embodiment. That is, the entire light-receiving area of ​​the light emitted from the light-emitting portion 20 in the interface 30b is an inclined portion. Moreover, in both the second and third embodiments, the cut-off line VLb of the inclined portion is inclined with respect to the X direction at the same predetermined angle (angle difference θ1) as in the first embodiment. Therefore, in these embodiments, it is also possible to suppress the reflected light from the light-emitting portion 20 at the interface 30b from returning to the light-emitting portion 20.

[0072] [Fourth and Fifth Embodiments]

[0073] Figure 9 This is a perspective view of the optical semiconductor element 100D (100) according to the fourth embodiment. Additionally, Figure 10 This is a top view of the optical semiconductor element 100E (100) of the fifth embodiment. The optical semiconductor element 100D of the fourth embodiment and the optical semiconductor element 100E of the fifth embodiment also have the same structure as the optical semiconductor element 100A of the first embodiment, and can obtain the same effect based on the same structure.

[0074] However, Figure 9 , 10 and Figure 1 , 2 A comparison reveals that the structures of the laminates 10 in the fourth and fifth embodiments differ from those in the first embodiment. In the laminate 10 of the optical semiconductor element 100D in the fourth embodiment and the laminate 10 of the optical semiconductor element 100E in the fifth embodiment, trenches 51 (50) extending in directions intersecting the Z and Y directions are respectively provided between the light-emitting portion 20 and the light-receiving portions 30A and 30B (30). In the fourth embodiment, as... Figure 9 As shown, the groove 51 is recessed from the upper surface 10a in the Z direction, extending in the Y direction with a predetermined width (e.g., a substantially constant width) in the X direction and a predetermined depth (e.g., a substantially constant depth) in the Z direction. In this case, the Y direction is an example of a fourth direction. On the other hand, in the fifth embodiment, as... Figure 10 As shown, the groove 51 is recessed from the upper surface 10a in the Z direction. However, in this structure, the groove 51 extends along the D4 direction, which is inclined relative to the Y direction at a predetermined angle (angle difference θ2). In this case, the D4 direction is an example of a fourth direction. The groove 51 has a predetermined width (e.g., a substantially constant width) in the direction intersecting the Z direction and the D4 direction, and a predetermined depth (e.g., a substantially constant depth) in the Z direction. It should be noted that, as Figure 6 As shown by the dashed line, the groove 51 (50) is set at least after S5 (S7).

[0075] In the fourth and fifth embodiments, the groove 51 (50) extends from the upper surface 10a of the laminate 10 to the lower cladding 12. This allows for the electrical separation of the light-emitting portion 20 from the light-receiving portion 30. Furthermore, according to this structure, it is sometimes possible to confine reflected light (stray light) at the interface 30b within the groove 51 (50).

[0076] Furthermore, as in the fifth embodiment, the trench 51 extends along the D4 direction, which is inclined relative to the Y direction. This suppresses the reflection of light emitted from the light-emitting part 20 at the interface between the trench 51 and the buried layer 42, preventing it from returning to the light-emitting part 20. In this case, through in-depth research by the inventors, it was determined that the absolute value of the acute angle difference θ2 is preferably greater than 0° and less than 18°. That is, when the absolute value of the angle difference θ2 is greater than 18°, sometimes the laser emitted from the light-emitting part 20 undergoes total internal reflection at the side surface (interface) of the trench 51 on the side of the light-emitting part 20, and does not propagate forward from the trench 51. In addition, the larger the absolute value of the angle difference θ2, the wider the spacing between the light-emitting part 20 and the light-receiving part 30, and the larger the light semiconductor element 100. Therefore, by making the absolute value of the acute angle difference θ2 greater than 0° and less than 18°, these problems can be avoided.

[0077] [Sixth Implementation Method]

[0078] Figure 11 This is a top view of the optical semiconductor element 100F (100) according to the sixth embodiment. The optical semiconductor element 100F has a plurality of pairs 101 arranged at intervals in the Y direction, each having a light-emitting portion 20 and a light-receiving portion 30F (30) as in the embodiment described above. According to this structure, for example, light of different wavelengths can be output from the plurality of pairs 101. Furthermore, for example, by setting any pair 101 as a backup pair 101 to be used when the currently used pair 101 fails, the reliability of the optical semiconductor element 100F can be improved. It should be noted that in this embodiment, the light-receiving portion 30F has a hexagonal shape that is elongated in the X direction when viewed from above in the direction opposite to the Z direction. In this case, even at the interface of the light-receiving portion 30F at the end in the X direction, it is possible to suppress the formation of the buried layers 41, 42 in steps (S3, see reference). Figure 6 Abnormal growth in ).

[0079] Furthermore, in the optical semiconductor element 100F, a trench 51 (50) between the light-emitting portion 20 and the light-receiving portion 30 is provided in the same manner as in the fourth and fifth embodiments. However, in this embodiment, trenches 52 (50) are also provided between adjacent pairs 101. Similar to the trenches 51 in the fourth and fifth embodiments, these trenches 51, 52 (50) extend from the upper surface 10a to the lower cladding layer 12. As a result, the two sides of the trench 50 can be electrically isolated. According to this configuration, it is sometimes possible to achieve the effect of confining the reflected light (stray light) at the interface 30b within the trenches 51, 52 (50).

[0080] [Seventh and Eighth Embodiments]

[0081] Figure 12 The optical semiconductor element 100G (100) of the seventh embodiment and Figure 3 A sectional view at the same location. Additionally, Figure 13 This is a perspective view of the optical semiconductor element 100H (100) of the eighth embodiment. The optical semiconductor element 100G of the seventh embodiment and the optical semiconductor element 100H of the eighth embodiment also have the same structure as the optical semiconductor element 100A of the first embodiment, and can obtain the same effect based on the same structure.

[0082] However, Figure 12 , 13 and Figure 3 , 1 A comparison reveals that the positions of the electrodes 19a in the seventh and eighth embodiments differ from those in the first embodiment. Specifically, the electrode 19a is not disposed on the lower surface 10b, but rather on the bottom surface 10c1 of the recess 10c provided in the laminate 10. The recess 10c is recessed from the upper surface 10a in the opposite direction to the Z-direction. In other words, the recess 10c opens in the Z-direction from the upper surface 10a. Furthermore, the recess 10c reaches the lower cladding layer 12. In other words, the lower cladding layer 12 is exposed on the bottom surface 10c1 of the recess 10c. In this structure, the electrode 19a is electrically connected to the lower cladding layer 12. Additionally, in… Figure 13 In this structure, electrode 19a is both the N-electrode used in the light-emitting part 20 and the N-electrode used in the light-receiving part 30. That is, electrode 19a is shared by both the light-emitting part 20 and the light-receiving part 30.

[0083] exist Figure 12 , 13 In this structure, current can be passed between electrodes 18a and 19a via a contact layer 16, an upper cladding layer 15, an active layer 17a (or an absorber layer 17b), and a lower cladding layer 12. Although the position of electrode 19a differs from that in the first embodiment, the same function and effect can be achieved in this structure.

[0084] In addition, such as Figure 13 As shown, a groove 52 (50) can also be provided between the recess 10c and the light-emitting part 20 and the light-receiving part 30. Moreover, this groove 52 can also be connected to the groove 51 (50) between the light-emitting part 20 and the light-receiving part 30. According to this structure, the groove 50 can be used to more reliably electrically isolate the various parts.

[0085] [Variation Example]

[0086] Figure 14 This is a top view of the optical semiconductor element 100I (100) of the first variant of the embodiment. Figure 14 and Figure 2 A comparison reveals that the optical semiconductor element 100I essentially possesses the same structure as the optical semiconductor element 100A of the first embodiment. However, in this modified example, the ridge portion 30c is offset in the Y direction (or the opposite direction of the Y direction) relative to the optical axis center Co of the light L emitted from the light-emitting unit 20 and reaching the interface 30b. Assuming that the ridge portion 30c becomes rounded during the manufacturing process of the optical semiconductor element 100, the reflected light L emitted from the light-emitting unit 20 at the ridge portion 30c may return to the light-emitting unit 20. Regarding this, according to this modified example, even if the ridge portion 30c becomes rounded, the light L emitted from the light-emitting unit 20 will not be reflected at the ridge portion 30c, thus avoiding such an undesirable situation.

[0087] Figure 15 This is a top view of the optical semiconductor element 100J (100) of the second variation of the embodiment. Figure 15 and Figure 8 A comparison reveals that the optical semiconductor element 100J essentially possesses the same structure as the optical semiconductor element 100C of the first embodiment. However, in this modified example, the valley line portion 30d is offset in the Y direction (or the opposite direction of the Y direction) relative to the optical axis center Co of the light L emitted from the light-emitting unit 20 and reaching the interface 30b. Assuming that the valley line portion 30d becomes rounded during the manufacturing process of the optical semiconductor element 100, the reflected light of the light L emitted from the light-emitting unit 20 at the valley line portion 30d may return to the light-emitting unit 20. Regarding this, according to this modified example, even if the valley line portion 30d becomes rounded, the light L emitted from the light-emitting unit 20 will not be reflected at the valley line portion 30d, thus avoiding such an undesirable situation.

[0088] Figure 16 This is a top view of the optical semiconductor element 100K (100) of the third variation of the embodiment. Figure 16 and Figure 2A comparison reveals that the optical semiconductor element 100K has a structure substantially the same as that of the optical semiconductor element 100A in the first embodiment. However, in this modified example, a trench 51 (50) substantially the same as that of the optical semiconductor element 100E in the fifth embodiment is provided between the light-emitting portion 20 and the light-receiving portion 30. In this modified example, the light-emitting portion 20 and the ridge portion 30c are arranged in the X direction. Therefore, it is assumed that without the trench 51, the light L emitted from the light-emitting portion 20 may reach the ridge portion 30c. In this regard, in this modified example, the light L emitted from the light-emitting portion 20 can be refracted in the trench 51, which extends in the D4 direction inclined relative to the Y direction. As a result, the optical axis center Co of the light L reaching the interface 30b can be shifted in the opposite direction to the Y direction relative to the ridge portion 30c. Therefore, according to this modified example, the same effect as that described in the first and second modified examples can also be obtained. It should be noted that by providing a groove 50 that faces the X direction while also facing the Y direction, the optical axis center Co of the light L reaching the interface 30b can be shifted in the Y direction relative to the ridge portion 30c. Furthermore, the same effect can be achieved when the light-receiving portion 30 has a valley portion 30d instead of the ridge portion 30c at the same position in the Y direction.

[0089] [Example of mounting optical semiconductor devices]

[0090] Figure 17 The flip-chip is mounted on substrate 201. Figure 12 A cross-sectional view of the mounting structure 200 of the optical semiconductor element 100G according to the seventh embodiment is shown. Figure 17 As shown, electrodes 18a and 19a are bonded to electrodes 201a and 201b disposed on substrate 201 via P-type solder 202a and N-type solder 202b, respectively, and are electrically connected. Compared with other mounting structures such as wire bonding, flip-chip mounting offers significant advantages in terms of high integration, miniaturization, thinning, improved luminous efficiency, and improved heat dissipation efficiency. However, if protrusions or warping as described above occur in the optical semiconductor element 100, problems such as reduced coupling efficiency with optical functional elements coupled to the light output from the optical semiconductor element 100 may arise. In this regard, in the optical semiconductor element 100 of the above embodiments, protrusions and warping can be suppressed, thus suppressing problems such as decreased coupling efficiency.

[0091] The above embodiments and modifications of the present invention have been illustrated, but these 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 spirit of the invention. Furthermore, the specifications of various structures, shapes, etc. (construction, type, orientation, model, size, length, width, thickness, height, quantity, configuration, position, material, etc.) can be appropriately modified for implementation.

[0092] For example, in the above embodiments and variations, the second direction is the crystal orientation [0-11] direction, but it is not limited to this, and it can also be the crystal orientation [01-1] direction. In addition, in the above embodiments and variations, the third direction is the crystal orientation [0-1-1] direction, but it is not limited to this, and it can also be the crystal orientation

[011] direction.

[0093] In addition, the interface (cutting line) can be gently curved or it can be a curved surface (curve).

[0094] Industrial availability

[0095] This invention can be used in substrate assemblies and clamping components.

[0096] Explanation of reference numerals in the attached figures:

[0097] 10…Layered bodies

[0098] 10a… Upper surface

[0099] 10b…lower surface

[0100] 10c…concave part

[0101] 10c1…bottom

[0102] 11…Substrate

[0103] 12… Lower cladding (first cladding)

[0104] 13…Lower blocking layer (current blocking layer)

[0105] 14…Upper blocking layer (current blocking layer)

[0106] 15… Upper cladding (second cladding)

[0107] 16…Contact Layer

[0108] 17a…Active Layer

[0109] 17b…Absorption layer

[0110] Electrodes 18a, 18b, 19a, 19b…

[0111] 20… Light-emitting part

[0112] 20a…Tabletop Construction (First Tabletop Construction)

[0113] 30a… Countertop Construction (Second Countertop Construction)

[0114] 20b…interface

[0115] 30b… Interface (slanted section)

[0116] 30, 30A, 30B, 30C, 30F... Light-receiving section

[0117] 30c…ridge section

[0118] 30d…Valleyline

[0119] 41, 42... Embedded layers

[0120] 50, 51, 52… trenches

[0121] 100, 100A, 100B, 100C, 100D, 100E, 100F, 100G, 100H, 100I, 100J, 100K… Optical semiconductor components

[0122] 101…

[0123] D4… ​​direction (fourth direction)

[0124] L…light

[0125] VLa, VLb... Cutting wire

[0126] X… direction (second direction)

[0127] Y… direction (third direction, fourth direction)

[0128] Z… direction (first direction)

[0129] θ1, θ2... angular difference.

Claims

1. An optical semiconductor element, wherein, The optical semiconductor element comprises: The light-emitting part has a first mesa structure comprising a first cladding layer, an active layer and a second cladding layer stacked in a first direction, and outputs light in a second direction intersecting the first direction; The light-receiving part has a first cladding layer stacked in the first direction, an absorption layer made of the same material as the active layer, and a second cladding layer and a second mesa structure separated from the first mesa structure in the second direction, and receives light emitted from the light-emitting part; as well as An embedded layer is disposed between the first mezzanine structure and the second mezzanine structure, and is disposed at two locations: one adjacent to the first mezzanine structure and the other to the second mezzanine structure in a third direction intersecting the first and second directions, and the other adjacent to the first mezzanine structure and the other to the second mezzanine structure in the opposite direction of the third direction. It also includes a current blocking layer. Regarding the interface between the second mesa structure and the embedded layer between the second mesa structure and the light-emitting part, within the light-receiving range of the light emitted from the light-emitting part, there is an inclined portion in the cross-section intersecting the first direction where the cut line is inclined at a predetermined angle relative to the second direction. The first direction is the crystal orientation [100] direction. The second direction is either the crystal orientation [0-11] direction or the crystal orientation [01-1] direction. The third direction is either the crystal orientation [0-1-1] direction or the crystal orientation [011] direction. The absolute value of the specified acute angle is 35° ± 30°.

2. The optical semiconductor element according to claim 1, wherein, A groove is provided between the light-emitting part and the light-receiving part, the groove being open in the first direction and extending in a fourth direction intersecting the first direction and the second direction.

3. The optical semiconductor element according to claim 2, wherein, The fourth direction is tilted relative to the third direction.

4. The optical semiconductor element according to claim 3, wherein, The absolute value of the acute angle difference between the fourth direction and the third direction is greater than 0° and less than 18°.

5. The optical semiconductor element according to any one of claims 1 to 4, wherein, Multiple pairs of light-emitting portions, each having a light-emitting portion and a light-receiving portion that receives light emitted from the light-emitting portion, are arranged at intervals in the third direction.

6. The optical semiconductor element according to claim 1, wherein, The interface has a ridge portion that protrudes in the opposite direction to the second direction or a valley portion that is recessed in the opposite direction to the second direction. The ridge portion or the valley portion is offset from the center of the optical axis of the light emitted from the light-emitting portion and reaching the interface in the third direction or the opposite direction of the third direction.

7. A method for manufacturing an optical semiconductor element, wherein the optical semiconductor element comprises: The light-emitting part has a first mesa structure comprising a first cladding layer, an active layer and a second cladding layer stacked in a first direction, and outputs light in a second direction intersecting the first direction; The light-receiving part has a first cladding layer stacked in the first direction, an absorption layer made of the same material as the active layer, and a second cladding layer and a second mesa structure separated from the first mesa structure in the second direction, and receives light emitted from the light-emitting part; as well as An embedded layer is disposed between the first mezzanine structure and the second mezzanine structure, and is disposed at two locations: one adjacent to the first mezzanine structure and the other to the second mezzanine structure in a third direction intersecting the first and second directions, and the other adjacent to the first mezzanine structure and the other to the second mezzanine structure in the opposite direction of the third direction. It also includes a current blocking layer. Regarding the interface between the second mesa structure and the embedded layer between the second mesa structure and the light-emitting part, within the light-receiving range of the light emitted from the light-emitting part, there is an inclined portion in the cross-section intersecting the first direction where the cut line is inclined at a predetermined angle relative to the second direction. The first direction is the crystal orientation [100] direction. The second direction is either the crystal orientation [0-11] direction or the crystal orientation [01-1] direction. The third direction is either the crystal orientation [0-1-1] direction or the crystal orientation [011] direction. The absolute value of the specified acute angle is 35° ± 30°, where, The method for manufacturing the optical semiconductor element includes: The process of forming a laminate by stacking the first cladding layer, the active layer, the absorbent layer, and the second cladding layer on a substrate; The process of forming the first mesa structure and the second mesa structure by etching the laminate to form recesses; and The process of forming the embedded layer by filling the recess between the first and second countertop structures and in the opposite directions of the third and third directions with the recesses adjacent to the first and second countertop structures respectively.

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