WO2011043174A1 - Optical semiconductor device and optical module using same - Google Patents

Optical semiconductor device and optical module using same Download PDF

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Publication number
WO2011043174A1
WO2011043174A1 PCT/JP2010/066083 JP2010066083W WO2011043174A1 WO 2011043174 A1 WO2011043174 A1 WO 2011043174A1 JP 2010066083 W JP2010066083 W JP 2010066083W WO 2011043174 A1 WO2011043174 A1 WO 2011043174A1
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Prior art keywords
laser diode
layer
photodiode
width
semiconductor device
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PCT/JP2010/066083
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French (fr)
Japanese (ja)
Inventor
秋山知之
菅原充
宇佐美真
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株式会社Ｑｄレーザ
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Publication of WO2011043174A1 publication Critical patent/WO2011043174A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/026—Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers
    • H01S5/0262—Photo-diodes, e.g. transceiver devices, bidirectional devices
    • H01S5/0264—Photo-diodes, e.g. transceiver devices, bidirectional devices for monitoring the laser-output

Definitions

  • the present invention relates to an optical semiconductor device and an optical module using the same.
  • Laser diodes change their light output due to temperature changes and deterioration over time.
  • a method of obtaining a constant optical output by detecting the optical output of the laser diode with a photodiode and controlling the driving current of the laser diode by feeding back the detection result.
  • Patent Documents 1 and 2 an optical semiconductor device in which a laser diode and a photodiode are integrated on the same substrate and the optical output of the laser diode is detected by the photodiode is known (for example, Patent Documents 1 and 2).
  • Patent Document 1 a photodiode is formed by performing impurity diffusion or crystal growth on a substrate on which a laser diode is formed, and the cost increases due to an increase in the number of steps for forming the photodiode.
  • Patent Document 2 since an external reflecting mirror is provided to allow laser light emitted from a laser diode to enter the photodiode, the cost increases due to an increase in the number of components.
  • An object of the present invention is to provide an optical semiconductor device capable of detecting the light output of a laser diode with a photodiode without increasing the cost, and an optical module using the same.
  • the present invention includes a semiconductor layer including a lower clad layer, an active layer, and an upper clad layer having a conductivity type opposite to the lower clad layer, which are sequentially stacked on a semiconductor substrate, and a front end surface that emits laser light;
  • a laser diode formed by extending the semiconductor layer between the front end surface and the rear end surface opposite to the front end surface, and formed in the width direction of the laser diode on the semiconductor substrate, and detects the light output of the laser diode
  • a photodiode for detecting the optical output of the laser diode can be integrated on the semiconductor substrate on which the laser diode is formed, an increase in cost due to an increase in the number of parts and an increase in the number of manufacturing steps is suppressed. be able to.
  • the width changing portion may be a narrow width portion in which the width of at least the upper cladding of the semiconductor layer is narrowed.
  • the laser diode may have a ridge portion made of the isolated upper clad layer, and the width changing portion may be formed by changing the width of the ridge portion. According to this configuration, part of the light stimulated and emitted by the laser diode can be guided to the photodiode, and the light output of the laser diode can be detected by the photodiode.
  • the photodiode includes a lower cladding layer, an active layer, and an upper cladding layer having a conductivity type opposite to the lower cladding layer, which are sequentially stacked on the semiconductor substrate, and the photodiode includes the active cladding.
  • the layer and the active layer of the laser diode may be connected. According to this configuration, light stimulated and emitted by the laser diode can be efficiently received by the photodiode.
  • the laser diode has a semiconductor mesa portion in which the lower cladding layer, the active layer, and the upper cladding layer are isolated, and the width changing portion is formed by changing the width of the semiconductor mesa portion. It can be set as the structure currently made. According to this configuration, part of the light stimulated and emitted by the laser diode can be guided to the photodiode, and the light output of the laser diode can be detected by the photodiode.
  • the photodiode includes a lower cladding layer, an active layer, and an upper cladding layer having a conductivity type opposite to the lower cladding layer, which are sequentially stacked on the semiconductor substrate, and the active layer included in the photodiode.
  • the active layer of the laser diode may be connected via a buried layer formed to cover the side surface of the semiconductor mesa portion.
  • the width changing portion may be configured to change in a step shape. According to this configuration, part of the light stimulated and emitted by the laser diode can be more reliably guided to the photodiode.
  • the photodiode may be provided on both sides so as to sandwich the laser diode. According to this configuration, the light receiving efficiency of the photodiode can be improved.
  • a low reflection film for the laser light provided on the front end surface, and a high reflection film for the laser light provided on the rear end surface, the width change portion and the rear end surface are provided.
  • An electrode for applying a voltage to the photodiode may be provided therebetween. According to this configuration, the light receiving efficiency of the photodiode can be improved.
  • the present invention includes the optical semiconductor device, and a drive circuit that receives a feedback of the optical output of the laser diode detected by the photodiode and supplies a drive current to the laser diode. It is a module. ADVANTAGE OF THE INVENTION According to this invention, the optical module which can keep the optical output of a laser diode constant can be obtained, suppressing the increase in cost.
  • an optical semiconductor device capable of detecting a light output of a laser diode with a photodiode and an optical module using the same without increasing the cost.
  • FIG. 1A is a schematic top view of the optical semiconductor device according to the first embodiment.
  • FIGS. 1B and 1C are cross-sectional views taken along lines AA and BB in FIG.
  • FIG. 2A to FIG. 2D are schematic cross-sectional views illustrating the method for manufacturing the optical semiconductor device according to the first embodiment.
  • FIG. 3A is a schematic top view for explaining light propagation in the optical semiconductor device according to the first embodiment.
  • FIGS. 3B to 3D are views of A in FIG.
  • FIG. 5 is a schematic cross-sectional view between ⁇ A and CC.
  • FIG. 4 is a schematic cross-sectional view illustrating the operation of the optical semiconductor device according to the first embodiment.
  • FIG. 5A is a schematic diagram showing a structure simulated for the light branching ratio when the width and length of narrow details are changed
  • FIG. 5B is a diagram showing the simulation result.
  • FIG. 6A is a schematic top view of the optical semiconductor device according to the second embodiment.
  • FIGS. 6B to 6D are diagrams from AA to CC in FIG. 6A.
  • FIG. 7A to FIG. 7D are schematic cross-sectional views illustrating a method for manufacturing an optical semiconductor device according to the second embodiment.
  • FIG. 8 is a block diagram of an optical module according to the third embodiment.
  • Example 1 is an example of an optical semiconductor device having a ridge-structure laser diode.
  • FIG. 1A is a schematic top view of the optical semiconductor device 100 according to the first embodiment
  • FIG. 1B is a schematic cross-sectional view taken along the line AA in FIG. 1A
  • FIG. It is a cross-sectional schematic diagram between BB of 1 (a).
  • the optical semiconductor device 100 according to the first embodiment includes a laser diode 12 and a photodiode 14 on the same semiconductor substrate 10 made of, for example, an n-type GaAs substrate. Is formed.
  • the photodiodes 14 are formed on both sides so as to sandwich the laser diode 12.
  • Both the laser diode 12 and the photodiode 14 are semiconductor layers in which a lower clad layer 22 made of an n-type AlGaAs layer, an active layer 24 and an upper clad layer 26 made of a p-type InGaP layer are sequentially laminated on the surface of the semiconductor substrate 10.
  • the lower clad layer 22 and the upper clad layer 26 may have opposite conductivity types.
  • a p-type GaAs substrate is used
  • the lower clad layer 22 is a p-type clad layer
  • the upper clad layer 26 is an n-type clad. It may be a layer.
  • the active layer 24 is a quantum dot active layer having a plurality of quantum dots 30 made of InAs in a base layer 28 made of a GaAs layer.
  • the laser diode 12 has a ridge portion 32 composed of an isolated upper clad layer 26. Concave portions 34 are formed on both sides of the ridge portion 32.
  • the semiconductor layer 20 included in the laser diode 12 is formed to extend between the front end face 16 and the rear end face 18 that is the end face opposite to the front end face 16.
  • a low reflection film (AR film) 37 for the wavelength of the emitted laser light is formed on the front end face 16, and a high reflection film (HR film) 38 for the wavelength of the emitted laser light is formed on the rear end face 18. Is formed. Thereby, the laser light is emitted from the front end face 16.
  • a contact layer 36 made of a p-type GaAs layer is formed on the ridge portion 32, and a p-electrode 40 A for the laser diode 12 is formed on the contact layer 36.
  • a p-electrode 40 A for the laser diode 12 is formed on the contact layer 36.
  • an n-electrode 42 that is commonly used by the laser diode 12 and the photodiode 14 is formed.
  • the laser diode 12 has a narrow portion 44 where the width of the ridge portion 32 is partially reduced. From the wide part 50 before and after the narrow part 44 to the narrow part 44, the width is narrowed stepwise.
  • the lower cladding layer 22 included in the photodiode 14 and the lower cladding layer 22 included in the laser diode 12 are connected because they are formed at the same time.
  • the active layer 24 included in the photodiode 14 and the active layer 24 included in the laser diode 12 are connected to each other. Are connected because they are formed at the same time.
  • the photodiode 14 has a terrace portion 46 composed of an isolated upper clad layer 26.
  • the terrace portion 46 is separated from the ridge portion 32 of the laser diode 12 by the recess 34.
  • a contact layer 36 made of a p-type GaAs layer is formed on the terrace portion 46.
  • a p-electrode 40B for the photodiode 14 is formed between the narrow portion 44 of the laser diode 12 and the rear end face 18 and on the contact layer 36 of the photodiode 14.
  • An insulating film 48 made of, for example, a silicon oxide film is formed so as to cover the terrace 46 and the recess 34 where the p-electrode 40B is not formed.
  • the pad portion 41 connected to the p-electrode 40A for the laser diode 12 is formed between the narrow width portion 44 and the front end face 16 and on the terrace portion 46 with an insulating film 48 interposed therebetween.
  • the p-electrode 40B for the photodiode 14 is also used as a pad portion.
  • 2 (a), 2 (b), and 2 (d) are schematic cross-sectional views corresponding to AA in FIG. 1 (a), and
  • FIG. 2 (c) is a cross-sectional view of FIG. It is a cross-sectional schematic diagram equivalent to between BB.
  • the lower cladding layer 22, the active layer 24, the upper cladding layer 26, and the contact layer 36 are sequentially deposited on the surface of the semiconductor substrate 10 by using, for example, MBE (Molecular Beam Epitaxy) method.
  • MBE Molecular Beam Epitaxy
  • the contact layer 36 and the upper cladding layer 26 are etched using, for example, a wet etching method.
  • a ridge portion 32 made of the upper cladding layer 26 is formed in the portion that becomes the laser diode 12
  • a terrace portion 46 made of the upper cladding layer 26 is formed in the portion that becomes the photodiode 14.
  • the narrow portion 44 in which the width of the ridge portion 32 is narrowed can be formed at the same time.
  • the insulating film 48 on the ridge portion 32, and between the narrow width portion 44 and the rear end face 18 and on the terrace portion 46. 48 are etched. Thereafter, the p-electrode 40A for the laser diode 12 is formed on the contact layer 36 of the ridge 32 where the insulating film 48 is etched, and the p-electrode 40B for the photodiode 14 is formed on the contact layer 36 of the terrace 46. .
  • a pad portion 41 is formed on the insulating film 48 of the terrace portion 46 between the narrow width portion 44 and the front end face 16.
  • an n-electrode 42 that is commonly used by the laser diode 12 and the photodiode 14 is formed. Thereby, the optical semiconductor device 100 according to the first embodiment shown in FIG. 1 is completed.
  • FIG. 3A is a schematic top view of the optical semiconductor device 100 according to the first embodiment.
  • FIGS. 3B to 3D are cross-sectional views taken along the line AA in FIG. FIG. Note that the arrows in FIG. 3A indicate the direction in which light is propagated, and the mesh portion in FIGS. 3B to 3D represents a waveguide region in which light propagates. ing.
  • the active layer 24 is sandwiched between the lower clad layer 22 and the upper clad layer 26 having a low refractive index. It is confined in the vicinity of the active layer 24.
  • the effective refractive index for light propagating in the vicinity of the active layer 24 under the ridge portion 32 is larger than the effective refractive index for light propagating in the vicinity of the active layer 24 under the recess 34 on both sides of the ridge portion 32. For this reason, light propagating in the vicinity of the active layer 24 is confined in the vicinity of the active layer 24 under the ridge portion 32.
  • the light propagating in the vicinity of the active layer 24 under the ridge portion 32 propagates when reaching the narrow width portion 44 where the width of the ridge portion 32 becomes narrow. Some of the light cannot travel straight, but propagates branching left and right. As described above, the propagating light branches right and left in the narrow portion 44 because the mode shape that can propagate in the narrow portion 44 can propagate in the wide portion 50 before and after the narrow portion 44. This is because it changes compared to the mode shape.
  • the light branched right and left by the narrow width portion 44 propagates under the concave portion 34 and is guided to the photodiode 14.
  • FIG. 4 shows the case where the n-electrode 42 on the back surface of the semiconductor substrate 10 is grounded, a voltage of + 2V is applied to the p-electrode 40A for the laser diode 12, and a voltage of ⁇ 1V is applied to the p-electrode 40B for the photodiode 14.
  • the electric field distribution (broken line in FIG. 4) is shown.
  • FIG. 4 by applying a forward bias by applying a voltage of +2 V to the p-electrode 40A for the laser diode 12, the holes 53 and the electrons 55 are recombined, and light is induced and emitted.
  • the stimulated emission propagates in the vicinity of the active layer 24 under the ridge portion 32. However, a part of the propagated light branches to the left and right at the narrow width portion 44 and propagates. Guided to the diode 14.
  • holes 53 and electrons 55 are generated by irradiation of the guided light, and the holes 53 and electrons 55 are generated by a reverse bias voltage ( ⁇ 1V) applied to the p-electrode 40 ⁇ / b> B for the photodiode 14. Being attracted by the electric field, a current is generated in the photodiode 14.
  • the laser diode 12 and the photodiode 14 are formed on the same semiconductor substrate 10.
  • the laser diode 12 includes a lower cladding layer 22, an active layer 24, and an upper cladding layer 26, and extends between a front end face 16 that emits laser light and a rear end face 18 that is an end face opposite to the front end face. It has a layer 20.
  • the laser diode 12 has an isolated ridge portion 32 made of the upper clad layer 26 and a narrow portion 44 due to the narrow width of the ridge portion 32.
  • the photodiodes 14 are formed on both sides of the laser diode 12 in the width direction.
  • the laser diode 12 Since the laser diode 12 has the narrow portion 44, a part of the light propagating in the vicinity of the active layer 24 under the ridge portion 32 branches to the left and right at the narrow portion 44 as described in FIGS. And is guided to the photodiode 14. Thereby, the light output of the laser diode 12 can be detected by the photodiode 14.
  • FIG. Fig.5 (a) is a schematic diagram which shows the structure used for simulation
  • FIG.5 (b) is a simulation result.
  • the simulation uses a structure in which the width of the wide portion 50 of the ridge portion 32 is 1.8 ⁇ m, the width of the narrow portion 44 is W ⁇ m, and the length is D ⁇ m.
  • the light splitting ratio was calculated when the change was made.
  • the light branching ratio is T for the proportion of light that travels straight under the ridge 32 and 1-T for the proportion of light that branches to the left and right (the proportion of light that branches and proceeds to the left and right is (1-T ) / 2).
  • the effective refractive index of the active layer 24 below the ridge 32 and the waveguide region where light propagates is 3.37748, and the effective refractive index around the waveguide region is 3. The calculation was performed as 36319.
  • the width W of the narrow portion 44 by reducing the width W of the narrow portion 44, the ratio 1-T of light propagating left and right increases. Further, increasing the length D of the narrow portion 44 also increases the ratio 1-T of the light propagating left and right.
  • the width W and length D of the narrow width portion 44 by changing the width W and length D of the narrow width portion 44, the branching ratio of the light branched to the left and right at the narrow width portion 44 changes, so that the freedom of design for obtaining a desired branching ratio is achieved. The degree is great.
  • the optical output of the laser diode 12 can be detected by the photodiode 14 formed on the same semiconductor substrate 10 as the laser diode 12. For this reason, it is not necessary to prepare a separate external photodiode, the increase in the number of components and the complexity of the assembly process can be suppressed, and the increase in cost can be suppressed.
  • the optical semiconductor device 100 according to the first embodiment can be manufactured in the same process as the process of manufacturing the laser diode having the ridge structure, and the manufacturing process is complicated. It will not become. Therefore, an increase in cost due to an increase in the number of manufacturing steps can be suppressed.
  • the active layer 24 included in the laser diode 12 and the active layer 24 included in the photodiode 14 are connected because they are formed at the same time.
  • the light branched right and left from the vicinity of the active layer 24 below the ridge portion 32 in the narrow width portion 44 propagates in the active layer 24 and is guided to the photodiode 14. That is, the light branched right and left by the narrow width portion 44 does not spread in the vertical direction (direction perpendicular to the surface of the semiconductor substrate 10), and the photodiode 14 can receive most of the branched light. For this reason, the photodiode 14 can obtain good light receiving efficiency.
  • the photodiodes 14 are preferably provided on both sides of the laser diode 12. Even when the photodiode 14 is provided only on one side of the laser diode 12, the light output of the laser diode 12 can be detected by the photodiode 14, but from the viewpoint of improving the light receiving efficiency, the laser diode 12 It is preferable that photodiodes 14 are provided on both sides.
  • the width narrows in a step shape from the wide portion 50 before and after the narrow portion 44 to the narrow portion 44.
  • the narrow width portion 44 can be branched left and right.
  • the p-electrode 40B for the photodiode 14 is preferably formed on a terrace portion 46 between the narrow width portion 44 and the rear end face 18. Since the rear end surface 18 is provided with a highly reflective film 38 for laser light, as shown in FIG. It can be detected by the photodiode 14. Thereby, the light reception efficiency in the photodiode 14 can be further improved. Further, the p electrode 40B for the photodiode 14 may be provided on the entire surface of the terrace portion 46 between the front end face 16 and the rear end face 18. Even in this case, the light reflected by the rear end face 18 can be detected by the photodiode 14.
  • the pad portion 41 connected to the p-electrode 40A is on the terrace portion 46, which is a wide portion, as shown in FIG. It is desirable to be formed. Therefore, in order to form the pad portion 41 on the terrace portion 46 and improve the light receiving efficiency of the photodiode 14, the p-electrode 40 B for the photodiode 14 has a terrace between the narrow width portion 44 and the rear end face 18. The case where it forms on the part 46 is preferable.
  • the laser diode 12 is a quantum dot laser
  • the present invention is not limited to this.
  • a semiconductor laser other than a quantum dot laser such as a quantum well laser may be used.
  • it may be a DFB (Distributed Feedback) type laser or a Fabry-Perot type laser. Even in these cases, it is possible to obtain an optical semiconductor device capable of detecting the light output of the laser diode with the photodiode while suppressing an increase in cost.
  • DFB Distributed Feedback
  • Example 2 is an example of an optical semiconductor device having a laser diode having a BH structure (buried heterostructure).
  • FIG. 6A is a schematic top view of the optical semiconductor device 200 according to the second embodiment, and FIGS. 6B to 6D are diagrams from AA to CC in FIG. 6A.
  • the optical semiconductor device 200 includes a laser diode 12 and a photodiode 14 on the same semiconductor substrate 10 made of, for example, an n-type InP substrate. Is formed.
  • the photodiodes 14 are formed on both sides so as to sandwich the laser diode 12.
  • Both the laser diode 12 and the photodiode 14 are formed on the surface of the semiconductor substrate 10, for example, a lower cladding layer 22 made of an n-type InP layer, an active layer 24 made of an InGaAsP-MQW (MultipleMultiQuantum Wells) layer, and a p-type InP layer. And an upper clad layer 26 made of a semiconductor layer 20 sequentially stacked.
  • the laser diode 12 has a semiconductor mesa portion 52 formed by the upper cladding layer 26, the active layer 24, and the lower cladding layer 22 being isolated.
  • the semiconductor mesa portion 52 is formed to extend between the front end face 16 and the rear end face 18.
  • a low reflection film (AR film) 37 for the wavelength of the emitted laser light is formed on the front end face 16, and a high reflection film (HR film) 38 for the wavelength of the emitted laser light is formed on the rear end face 18. Is formed.
  • a buried layer 54 made of an n-type InP layer is formed so as to cover the side surface of the semiconductor mesa portion 52.
  • a contact layer 36 made of a p-type InGaAs layer is formed on the semiconductor mesa portion 52, and a p-electrode 40A for the laser diode 12 is formed on the contact layer 36.
  • a p-electrode 40A for the laser diode 12 is formed on the contact layer 36.
  • an n-electrode 42 that is commonly used by the laser diode 12 and the photodiode 14 is formed on the back surface of the semiconductor substrate 10.
  • the laser diode 12 has a narrow width portion 44 in which the width of the semiconductor mesa portion 52 (that is, the lower cladding layer 22, the active layer 24, and the upper cladding layer 26) is partially reduced. From the wide part 50 before and after the narrow part 44 to the narrow part 44, the width is narrowed stepwise.
  • the side surface of the semiconductor layer 20 included in the photodiode 14 is covered with a buried layer 54. That is, the active layer 24 included in the laser diode 12 and the active layer 24 included in the photodiode 14 are connected via the buried layer 54.
  • the p for the photodiode 14 is connected via a contact layer 36 made of a p-type InGaAs layer.
  • An electrode 40B is formed.
  • An insulating film 48 made of, for example, a silicon oxide film is formed so as to cover a portion of the contact layer 36 where the p-electrode 40B is not formed.
  • the pad portion 41 connected to the p-electrode 40A for the laser diode 12 is on the insulating film 48 formed between the narrow width portion 44 and the front end face 16 and in front of the photodiode 14 (front end face 16 side). Is formed.
  • the p-electrode 40B for the photodiode 14 is also used as a pad portion.
  • FIGS. 7A to 7D are schematic cross-sectional views corresponding to the line CC in FIG. 7A
  • FIG. 7C is a cross-sectional view of FIG. It is a cross-sectional schematic diagram equivalent to between BB.
  • the lower clad layer 22, the active layer 24, the upper clad layer 26, and the contact layer 36 are sequentially deposited on the surface of the semiconductor substrate 10 by using, for example, MBE (Molecular Beam Epitaxy) method.
  • MBE Molecular Beam Epitaxy
  • the contact layer 36, the upper cladding layer 26, the active layer 24, and the lower cladding layer 22 are, for example, dried. Etching is performed using an etching method. As a result, a semiconductor mesa portion 52 composed of the isolated upper clad layer 26, active layer 24, and lower clad layer 22 is formed in the portion to become the laser diode 12. Further, the narrow width portion 44 where the width of the semiconductor mesa portion 52 is narrowed can be formed at the same time.
  • a buried layer 54 is buried in a portion etched to form the semiconductor mesa portion 52.
  • the insulating film 48 is etched. Thereafter, a p-electrode 40A for the laser diode 12 and a p-electrode 40B for the photodiode 14 are formed at the locations where the insulating film 48 has been etched.
  • a pad portion 41 is formed on the insulating film 48 between the narrow width portion 44 and the front end face 16 and in front of the photodiode 14.
  • An n-electrode 42 that is used in common by the laser diode 12 and the photodiode 14 is formed on the back surface of the semiconductor substrate 10.
  • the laser diode 12 has the narrow portion 44 due to the narrow width of the semiconductor mesa portion 52. For this reason, as shown in FIGS. 6A to 6D, a part of the light propagating in the vicinity of the active layer 24 is left and right at the narrow portion 44 for the same reason as described in the first embodiment.
  • the light is branched and propagated and guided to the photodiode 14. Thereby, the light output of the laser diode 12 can be detected by the photodiode 14.
  • the second embodiment as in the first embodiment, it is not necessary to prepare a separate external photodiode. Therefore, it is possible to suppress an increase in the number of components and a complicated assembly process, thereby suppressing an increase in cost. it can.
  • Example 2 the case where the narrow width portion 44 is formed by narrowing the width of the semiconductor mesa portion 52 (the width of the upper cladding layer 26, the active layer 24, and the lower cladding layer 22) is shown.
  • the present invention is not limited to this, and it is sufficient that the narrow portion 44 is formed by at least the width of the upper cladding layer 26 being narrowed. Even in this case, part of the light propagating in the vicinity of the active layer 24 can be branched left and right by the narrow width portion 44.
  • the narrow width portion 44 when the narrow width portion 44 is formed by narrowing the width of the semiconductor mesa portion 52, the laser diode having the BH structure (buried heterostructure).
  • the narrow portion 44 is formed by reducing the width of the entire semiconductor mesa portion 52 as in the optical semiconductor device 200 according to the second embodiment. Is preferred.
  • the active layer 24 included in the laser diode 12 and the active layer 24 included in the photodiode are connected via a buried layer 54 formed so as to cover the side surface of the semiconductor mesa portion 52 included in the laser diode 12.
  • a buried layer 54 formed so as to cover the side surface of the semiconductor mesa portion 52 included in the laser diode 12.
  • the laser diode 12 is a quantum well laser
  • the present invention is not limited to this.
  • a semiconductor laser other than the quantum well laser such as a quantum dot laser as in the first embodiment. But you can.
  • it may be a DFB type laser or a Fabry-Perot type laser. Even in these cases, it is possible to obtain an optical semiconductor device capable of detecting the light output of the laser diode with the photodiode while suppressing an increase in cost.
  • the laser diode 12 has been described as an example in which the ridge portion 32 or the semiconductor mesa portion 52 has the narrow width portion 44 in which the width is partially reduced.
  • the ridge portion 32 or the semiconductor mesa portion 52 may be partially enlarged.
  • the laser diode 12 has the width changing portion in which the width of the ridge portion 32 or the semiconductor mesa portion 52 changes, so that one of the light propagating under the ridge portion 32 or in the vicinity of the active layer 24 of the semiconductor mesa portion 52 can be obtained.
  • the part leaks to the left and right at the width changing part and propagates.
  • the optical output of the laser diode 12 can be detected by the photodiode 14. Further, it is preferable that the width changes in a stepped manner to the width changing portion.
  • Example 3 is an example of an optical module including the optical semiconductor device 100 according to Example 1.
  • FIG. FIG. 8 is a block diagram illustrating the configuration of the optical module 300 according to the third embodiment.
  • the optical module 300 according to the third embodiment includes an optical semiconductor device 100 according to the first embodiment that includes the laser diode 12 and the photodiode 14, a drive circuit 56, an APC (Auto Power Control) circuit 58, and An input unit 60 is included.
  • the input unit 60 receives a transmission data signal 62 from the outside and outputs a transmission data signal to the drive circuit 56.
  • the drive circuit 56 outputs the drive current 66 to the laser diode 12 while controlling the drive current 66 based on the control signal 64.
  • the laser diode 12 emits a laser beam 68 with an optical output corresponding to the drive current 66.
  • the photodiode 14 detects the light output of the laser diode 12 from a part 70 of the light stimulated and emitted by the active layer 24 of the laser diode 12, and generates a monitor current 72 corresponding to the light output.
  • the data is output to the APC circuit 58.
  • the APC circuit 58 compares the monitor current 72 with the reference current and outputs a control signal 64 to the drive circuit 56.
  • the optical output of the laser diode 12 is detected by the photodiode 14, and the detected optical output is fed back to the drive circuit 56 by the APC circuit 58.
  • the drive circuit 56 controls the drive current 66 based on the control signal 64 fed back by the APC circuit 58 and outputs the drive current 66 to the laser diode 12. Thereby, the light output of the laser diode 12 can be kept constant.
  • the optical module 300 according to the third embodiment includes the optical semiconductor device 100 according to the first embodiment, it is not necessary to prepare an external photodiode separate from the laser diode, and an increase in cost can be suppressed.
  • the optical module 300 according to the third embodiment may include the optical semiconductor device 200 according to the second embodiment. Even in this case, since it is not necessary to prepare a separate external photodiode, an increase in cost can be suppressed.

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  • Semiconductor Lasers (AREA)

Abstract

Disclosed is an optical semiconductor device that has a semiconductor layer (20) containing a lower clad layer (22), an active layer (24), and an upper clad layer (26) that has the opposite conductivity from the lower clad layer (22), that have been layered in the given order on a semiconductor substrate (10). The optical semiconductor device is provided with a laser diode (12) formed by the semiconductor layer (20) extending between a front end surface (16) from which laser light is emitted and a back end surface (18) that is the end surface on the reverse side from the front end surface (16), and photodiodes (14) that detect the light output of the laser diode (12) and are formed on the semiconductor substrate (10) in the widthwise direction of the laser diode (12). The laser diode (12) has a varied-width section wherein, of the semiconductor layer (20), at least the width of the upper clad layer (26) varies.

Description

光半導体装置及びそれを用いた光モジュールOptical semiconductor device and optical module using the same
　本発明は、光半導体装置及びそれを用いた光モジュールに関する。 The present invention relates to an optical semiconductor device and an optical module using the same.
　レーザダイオードは、温度変化や経時劣化などによって光出力が変化する。レーザダイオードの光出力を一定に保つために、フォトダイオードでレーザダイオードの光出力を検出し、その検出結果をフィードバックしてレーザダイオードの駆動電流を制御することで、一定の光出力を得る方法が知られている。また、レーザダイオードの光出力を検出することで、レーザダイオードが壊れていないかチェックすることもできる。 Laser diodes change their light output due to temperature changes and deterioration over time. In order to keep the optical output of the laser diode constant, there is a method of obtaining a constant optical output by detecting the optical output of the laser diode with a photodiode and controlling the driving current of the laser diode by feeding back the detection result. Are known. It is also possible to check whether the laser diode is broken by detecting the light output of the laser diode.
　例えば、同一基板上にレーザダイオードとフォトダイオードとを集積し、レーザダイオードの光出力をフォトダイオードで検出する光半導体装置が知られている（例えば、特許文献１及び２）。 For example, an optical semiconductor device in which a laser diode and a photodiode are integrated on the same substrate and the optical output of the laser diode is detected by the photodiode is known (for example, Patent Documents 1 and 2).
特開平８－１８１５２号公報JP-A-8-18152 特開平６－２２４４０６号公報JP-A-6-224406
　レーザダイオードの光出力をフォトダイオードで検出するには、レーザダイオードとは別個に外付けのフォトダイオードを用意することが一般的である。このため、部品数の増加によりコストが増大してしまう。また、外付けのフォトダイオードを用いる場合、レーザダイオードとフォトダイオードとが光結合するように高精度で位置合せをする必要があり、組み立て工程の複雑化によるコストの増大も生じる。 In order to detect the optical output of a laser diode with a photodiode, it is common to prepare an external photodiode separately from the laser diode. For this reason, cost will increase by the increase in the number of parts. In addition, when an external photodiode is used, it is necessary to align the laser diode and the photodiode with high precision so that the laser diode and the photodiode are optically coupled, and the cost is increased due to a complicated assembly process.
　例えば、特許文献１では、レーザダイオードが形成された基板に、不純物拡散又は結晶成長を行うことでフォトダイオードを形成しており、フォトダイオード形成のための工程数の増加によりコストが増大する。例えば、特許文献２では、レーザダイオードから出射されるレーザ光をフォトダイオードに入射させるために外部反射鏡を設けているため、部品数の増加によりコストが増大する。 For example, in Patent Document 1, a photodiode is formed by performing impurity diffusion or crystal growth on a substrate on which a laser diode is formed, and the cost increases due to an increase in the number of steps for forming the photodiode. For example, in Patent Document 2, since an external reflecting mirror is provided to allow laser light emitted from a laser diode to enter the photodiode, the cost increases due to an increase in the number of components.
　本発明は、コストを増大させることなく、レーザダイオードの光出力をフォトダイオードで検出することが可能な光半導体装置及びそれを用いた光モジュールを提供することを目的とする。 An object of the present invention is to provide an optical semiconductor device capable of detecting the light output of a laser diode with a photodiode without increasing the cost, and an optical module using the same.
　本発明は、半導体基板上に順次積層された下部クラッド層と活性層と前記下部クラッド層と反対の導電型の上部クラッド層とを含む半導体層を有し、レーザ光を出射する前端面と前記前端面と反対側の後端面との間を前記半導体層が延在して形成されたレーザダイオードと、前記半導体基板上に前記レーザダイオードの幅方向に形成され、前記レーザダイオードの光出力を検出するフォトダイオードと、を具備し、前記レーザダイオードは、前記半導体層のうちの少なくとも前記上部クラッドの幅が変化する幅変化部を有することを特徴とする光半導体装置である。本発明によれば、レーザダイオードが形成された半導体基板上に、そのレーザダイオードの光出力を検出するフォトダイオードを集積できるため、部品数の増加や製造工数の増加に伴うコストの増大を抑制することができる。 The present invention includes a semiconductor layer including a lower clad layer, an active layer, and an upper clad layer having a conductivity type opposite to the lower clad layer, which are sequentially stacked on a semiconductor substrate, and a front end surface that emits laser light; A laser diode formed by extending the semiconductor layer between the front end surface and the rear end surface opposite to the front end surface, and formed in the width direction of the laser diode on the semiconductor substrate, and detects the light output of the laser diode A laser diode, wherein the laser diode has a width changing portion in which a width of at least the upper cladding of the semiconductor layer is changed. According to the present invention, since a photodiode for detecting the optical output of the laser diode can be integrated on the semiconductor substrate on which the laser diode is formed, an increase in cost due to an increase in the number of parts and an increase in the number of manufacturing steps is suppressed. be able to.
　上記構成において、前記幅変化部は、前記半導体層のうちの少なくとも前記上部クラッドの幅が狭まる狭幅部である構成とすることができる。 In the above configuration, the width changing portion may be a narrow width portion in which the width of at least the upper cladding of the semiconductor layer is narrowed.
　上記構成において、前記レーザダイオードは、孤立した前記上部クラッド層からなるリッジ部を有し、前記幅変化部は、前記リッジ部の幅が変化することにより形成されている構成とすることができる。この構成によれば、レーザダイオードで誘導放出された光の一部をフォトダイオードに導くことができ、レーザダイオードの光出力をフォトダイオードで検出できる。 In the above configuration, the laser diode may have a ridge portion made of the isolated upper clad layer, and the width changing portion may be formed by changing the width of the ridge portion. According to this configuration, part of the light stimulated and emitted by the laser diode can be guided to the photodiode, and the light output of the laser diode can be detected by the photodiode.
　上記構成において、前記フォトダイオードは、前記半導体基板上に順次積層された下部クラッド層と活性層と前記下部クラッド層と反対の導電型の上部クラッド層とを有し、前記フォトダイオードが有する前記活性層と前記レーザダイオードが有する前記活性層とは接続されている構成とすることができる。この構成によれば、レーザダイオードで誘導放出された光をフォトダイオードで効率よく受光することができる。 In the above configuration, the photodiode includes a lower cladding layer, an active layer, and an upper cladding layer having a conductivity type opposite to the lower cladding layer, which are sequentially stacked on the semiconductor substrate, and the photodiode includes the active cladding. The layer and the active layer of the laser diode may be connected. According to this configuration, light stimulated and emitted by the laser diode can be efficiently received by the photodiode.
　上記構成において、前記レーザダイオードは、前記下部クラッド層と前記活性層と前記上部クラッド層とが孤立した半導体メサ部を有し、前記幅変化部は前記半導体メサ部の幅が変化することにより形成されている構成とすることができる。この構成によれば、レーザダイオードで誘導放出された光の一部をフォトダイオードに導くことができ、レーザダイオードの光出力をフォトダイオードで検出できる。 In the above configuration, the laser diode has a semiconductor mesa portion in which the lower cladding layer, the active layer, and the upper cladding layer are isolated, and the width changing portion is formed by changing the width of the semiconductor mesa portion. It can be set as the structure currently made. According to this configuration, part of the light stimulated and emitted by the laser diode can be guided to the photodiode, and the light output of the laser diode can be detected by the photodiode.
　上記構成において、前記フォトダイオードは、前記半導体基板上に順次積層された下部クラッド層と活性層と前記下部クラッド層と反対の導電型の上部クラッド層とを有し、前記フォトダイオードが有する活性層と前記レーザダイオードが有する活性層とは、前記半導体メサ部の側面を覆うように形成された埋め込み層を介して接続している構成とすることができる。 In the above configuration, the photodiode includes a lower cladding layer, an active layer, and an upper cladding layer having a conductivity type opposite to the lower cladding layer, which are sequentially stacked on the semiconductor substrate, and the active layer included in the photodiode. The active layer of the laser diode may be connected via a buried layer formed to cover the side surface of the semiconductor mesa portion.
　上記構成において、前記幅変化部へは段差状に幅が変化する構成とすることができる。この構成によれば、レーザダイオードで誘導放出された光の一部をより確実にフォトダイオードに導くことができる。 In the above configuration, the width changing portion may be configured to change in a step shape. According to this configuration, part of the light stimulated and emitted by the laser diode can be more reliably guided to the photodiode.
　上記構成において、前記フォトダイオードは、前記レーザダイオードを挟むように両側に設けられている構成とすることができる。この構成によれば、フォトダイオードの受光効率を向上させることができる。 In the above configuration, the photodiode may be provided on both sides so as to sandwich the laser diode. According to this configuration, the light receiving efficiency of the photodiode can be improved.
　上記構成において、前記前端面に設けられた前記レーザ光に対する低反射膜と、前記後端面に設けられた前記レーザ光に対する高反射膜と、を具備し、前記幅変化部と前記後端面との間に、前記フォトダイオードに電圧を印加するための電極が設けられている構成とすることができる。この構成によれば、フォトダイオードの受光効率を向上させることができる。 In the above-described configuration, a low reflection film for the laser light provided on the front end surface, and a high reflection film for the laser light provided on the rear end surface, the width change portion and the rear end surface are provided. An electrode for applying a voltage to the photodiode may be provided therebetween. According to this configuration, the light receiving efficiency of the photodiode can be improved.
　本発明は、上記光半導体装置と、前記フォトダイオードで検出された前記レーザダイオードの光出力のフィードバックを受けて前記レーザダイオードに駆動電流を供給する駆動回路と、を具備することを特徴とする光モジュールである。本発明によれば、レーザダイオードの光出力を一定に保つことができる光モジュールをコストの増加を抑制しつつ得ることができる。 The present invention includes the optical semiconductor device, and a drive circuit that receives a feedback of the optical output of the laser diode detected by the photodiode and supplies a drive current to the laser diode. It is a module. ADVANTAGE OF THE INVENTION According to this invention, the optical module which can keep the optical output of a laser diode constant can be obtained, suppressing the increase in cost.
　本発明によれば、コストを増大させることなく、レーザダイオードの光出力をフォトダイオードで検出することが可能な光半導体装置及びそれを用いた光モジュールを得ることができる。 According to the present invention, it is possible to obtain an optical semiconductor device capable of detecting a light output of a laser diode with a photodiode and an optical module using the same without increasing the cost.
図１（ａ）は、実施例１に係る光半導体装置の上面模式図であり、図１（ｂ）及び図１（ｃ）は、図１（ａ）のＡ－Ａ間及びＢ－Ｂ間の断面模式図である。FIG. 1A is a schematic top view of the optical semiconductor device according to the first embodiment. FIGS. 1B and 1C are cross-sectional views taken along lines AA and BB in FIG. FIG. 図２（ａ）から図２（ｄ）は、実施例１に係る光半導体装置の製造方法を示す断面模式図である。FIG. 2A to FIG. 2D are schematic cross-sectional views illustrating the method for manufacturing the optical semiconductor device according to the first embodiment. 図３（ａ）は、実施例１に係る光半導体装置における光の伝搬を説明するための上面模式図であり、図３（ｂ）から図３（ｄ）は、図３（ａ）のＡ－Ａ間からＣ－Ｃ間の断面模式図である。FIG. 3A is a schematic top view for explaining light propagation in the optical semiconductor device according to the first embodiment. FIGS. 3B to 3D are views of A in FIG. FIG. 5 is a schematic cross-sectional view between −A and CC. 図４は、実施例１に係る光半導体装置の動作について説明する断面模式図である。FIG. 4 is a schematic cross-sectional view illustrating the operation of the optical semiconductor device according to the first embodiment. 図５（ａ）は、狭細部の幅や長さを変化させた場合の光の分岐比についてシミュレーションした構造を示す模式図であり、図５（ｂ）は、シミュレーション結果を示す図である。FIG. 5A is a schematic diagram showing a structure simulated for the light branching ratio when the width and length of narrow details are changed, and FIG. 5B is a diagram showing the simulation result. 図６（ａ）は、実施例２に係る光半導体装置の上面模式図であり、図６（ｂ）から図６（ｄ）は、図６（ａ）のＡ－Ａ間からＣ－Ｃ間の断面模式図である。FIG. 6A is a schematic top view of the optical semiconductor device according to the second embodiment. FIGS. 6B to 6D are diagrams from AA to CC in FIG. 6A. FIG. 図７（ａ）から図７（ｄ）は、実施例２に係る光半導体装置の製造方法を示す断面模式図である。FIG. 7A to FIG. 7D are schematic cross-sectional views illustrating a method for manufacturing an optical semiconductor device according to the second embodiment. 図８は、実施例３に係る光モジュールのブロック図である。FIG. 8 is a block diagram of an optical module according to the third embodiment.
　以下、図面を参照して、本発明の実施例を説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
　実施例１は、リッジ構造のレーザダイオードを有する場合の光半導体装置の例である。図１（ａ）は実施例１に係る光半導体装置１００の上面模式図であり、図１（ｂ）は図１（ａ）のＡ－Ａ間の断面模式図、図１（ｃ）は図１（ａ）のＢ－Ｂ間の断面模式図である。図１（ａ）から図１（ｃ）のように、実施例１に係る光半導体装置１００は、例えばｎ型ＧａＡｓ基板からなる同一の半導体基板１０上に、レーザダイオード１２とフォトダイオード１４とが形成されている。フォトダイオード１４は、レーザダイオード１２を挟むように両側に形成されている。 Example 1 is an example of an optical semiconductor device having a ridge-structure laser diode. FIG. 1A is a schematic top view of the optical semiconductor device 100 according to the first embodiment, FIG. 1B is a schematic cross-sectional view taken along the line AA in FIG. 1A, and FIG. It is a cross-sectional schematic diagram between BB of 1 (a). As shown in FIGS. 1A to 1C, the optical semiconductor device 100 according to the first embodiment includes a laser diode 12 and a photodiode 14 on the same semiconductor substrate 10 made of, for example, an n-type GaAs substrate. Is formed. The photodiodes 14 are formed on both sides so as to sandwich the laser diode 12.
　レーザダイオード１２及びフォトダイオード１４は共に、半導体基板１０表面上に、ｎ型ＡｌＧａＡｓ層からなる下部クラッド層２２と活性層２４とｐ型ＩｎＧａＰ層からなる上部クラッド層２６とが順次積層された半導体層２０を有する。なお、下部クラッド層２２と上部クラッド層２６とは、反対の導電型であれば良く、例えば、ｐ型ＧａＡｓ基板を用い、下部クラッド層２２がｐ型クラッド層、上部クラッド層２６がｎ型クラッド層である場合でもよい。活性層２４は、ＧａＡｓ層からなるベース層２８内にＩｎＡｓからなる複数の量子ドット３０を有する量子ドット活性層である。 Both the laser diode 12 and the photodiode 14 are semiconductor layers in which a lower clad layer 22 made of an n-type AlGaAs layer, an active layer 24 and an upper clad layer 26 made of a p-type InGaP layer are sequentially laminated on the surface of the semiconductor substrate 10. 20 The lower clad layer 22 and the upper clad layer 26 may have opposite conductivity types. For example, a p-type GaAs substrate is used, the lower clad layer 22 is a p-type clad layer, and the upper clad layer 26 is an n-type clad. It may be a layer. The active layer 24 is a quantum dot active layer having a plurality of quantum dots 30 made of InAs in a base layer 28 made of a GaAs layer.
　レーザダイオード１２は、孤立した上部クラッド層２６からなるリッジ部３２を有する。リッジ部３２の両側には凹部３４が形成されている。レーザダイオード１２が有する半導体層２０は、前端面１６と前端面１６と反対側の端面である後端面１８との間を延在して形成されている。前端面１６には、出射されるレーザ光の波長に対する低反射膜（ＡＲ膜）３７が形成されていて、後端面１８には、出射されるレーザ光の波長に対する高反射膜（ＨＲ膜）３８が形成されている。これにより、レーザ光は前端面１６から出射される。 The laser diode 12 has a ridge portion 32 composed of an isolated upper clad layer 26. Concave portions 34 are formed on both sides of the ridge portion 32. The semiconductor layer 20 included in the laser diode 12 is formed to extend between the front end face 16 and the rear end face 18 that is the end face opposite to the front end face 16. A low reflection film (AR film) 37 for the wavelength of the emitted laser light is formed on the front end face 16, and a high reflection film (HR film) 38 for the wavelength of the emitted laser light is formed on the rear end face 18. Is formed. Thereby, the laser light is emitted from the front end face 16.
　リッジ部３２上には、ｐ型ＧａＡｓ層からなるコンタクト層３６が形成され、コンタクト層３６上には、レーザダイオード１２用のｐ電極４０Ａが形成されている。半導体基板１０裏面には、レーザダイオード１２とフォトダイオード１４とで共通に用いられるｎ電極４２が形成されている。レーザダイオード１２は、リッジ部３２の幅が一部で狭まる狭幅部４４を有する。狭幅部４４前後の幅広部５０から狭幅部４４へは段差状に幅が狭まっている。 A contact layer 36 made of a p-type GaAs layer is formed on the ridge portion 32, and a p-electrode 40 A for the laser diode 12 is formed on the contact layer 36. On the back surface of the semiconductor substrate 10, an n-electrode 42 that is commonly used by the laser diode 12 and the photodiode 14 is formed. The laser diode 12 has a narrow portion 44 where the width of the ridge portion 32 is partially reduced. From the wide part 50 before and after the narrow part 44 to the narrow part 44, the width is narrowed stepwise.
　フォトダイオード１４が有する下部クラッド層２２とレーザダイオード１２が有する下部クラッド層２２とは、同時に形成されるため接続されており、フォトダイオード１４が有する活性層２４とレーザダイオード１２が有する活性層２４とは、同時に形成されるため接続されている。 The lower cladding layer 22 included in the photodiode 14 and the lower cladding layer 22 included in the laser diode 12 are connected because they are formed at the same time. The active layer 24 included in the photodiode 14 and the active layer 24 included in the laser diode 12 are connected to each other. Are connected because they are formed at the same time.
　フォトダイオード１４は、孤立した上部クラッド層２６からなるテラス部４６を有する。テラス部４６は、凹部３４により、レーザダイオード１２のリッジ部３２と分離されている。テラス部４６上には、ｐ型ＧａＡｓ層からなるコンタクト層３６が形成されている。レーザダイオード１２の狭幅部４４と後端面１８との間であって、フォトダイオード１４が有するコンタクト層３６上には、フォトダイオード１４用のｐ電極４０Ｂが形成されている。ｐ電極４０Ｂが形成されていない部分のテラス部４６と凹部３４とを覆うように、例えば酸化シリコン膜からなる絶縁膜４８が形成されている。 The photodiode 14 has a terrace portion 46 composed of an isolated upper clad layer 26. The terrace portion 46 is separated from the ridge portion 32 of the laser diode 12 by the recess 34. A contact layer 36 made of a p-type GaAs layer is formed on the terrace portion 46. A p-electrode 40B for the photodiode 14 is formed between the narrow portion 44 of the laser diode 12 and the rear end face 18 and on the contact layer 36 of the photodiode 14. An insulating film 48 made of, for example, a silicon oxide film is formed so as to cover the terrace 46 and the recess 34 where the p-electrode 40B is not formed.
　レーザダイオード１２用のｐ電極４０Ａに接続するパッド部４１は、狭幅部４４と前端面１６との間であって、テラス部４６上に絶縁膜４８を介して形成されている。フォトダイオード１４用のｐ電極４０Ｂは、パッド部としても用いられる。 The pad portion 41 connected to the p-electrode 40A for the laser diode 12 is formed between the narrow width portion 44 and the front end face 16 and on the terrace portion 46 with an insulating film 48 interposed therebetween. The p-electrode 40B for the photodiode 14 is also used as a pad portion.
　次に、図２（ａ）から図２（ｄ）を用い、実施例１に係る光半導体装置１００の製造方法を説明する。図２（ａ）、図２（ｂ）及び図２（ｄ）は、図１（ａ）のＡ－Ａ間に相当する断面模式図であり、図２（ｃ）は、図１（ａ）のＢ－Ｂ間に相当する断面模式図である。図２（ａ）のように、例えばＭＢＥ（Molecular Beam Epitaxy）法を用い、半導体基板１０表面上に、下部クラッド層２２、活性層２４、上部クラッド層２６、及びコンタクト層３６を順次堆積する。 Next, a method for manufacturing the optical semiconductor device 100 according to the first embodiment will be described with reference to FIGS. 2 (a) to 2 (d). 2 (a), 2 (b), and 2 (d) are schematic cross-sectional views corresponding to AA in FIG. 1 (a), and FIG. 2 (c) is a cross-sectional view of FIG. It is a cross-sectional schematic diagram equivalent to between BB. As shown in FIG. 2A, the lower cladding layer 22, the active layer 24, the upper cladding layer 26, and the contact layer 36 are sequentially deposited on the surface of the semiconductor substrate 10 by using, for example, MBE (Molecular Beam Epitaxy) method.
　図２（ｂ）及び図２（ｃ）のように、コンタクト層３６上に形成したマスク層をマスクとして、コンタクト層３６と上部クラッド層２６とを、例えばウエットエッチング法を用いてエッチングする。これにより、レーザダイオード１２となる部分においては、上部クラッド層２６からなるリッジ部３２が形成され、フォトダイオード１４となる部分においては、上部クラッド層２６からなるテラス部４６が形成される。また、リッジ部３２の幅が狭まる狭幅部４４も同時に形成することができる。 2B and 2C, using the mask layer formed on the contact layer 36 as a mask, the contact layer 36 and the upper cladding layer 26 are etched using, for example, a wet etching method. As a result, a ridge portion 32 made of the upper cladding layer 26 is formed in the portion that becomes the laser diode 12, and a terrace portion 46 made of the upper cladding layer 26 is formed in the portion that becomes the photodiode 14. Further, the narrow portion 44 in which the width of the ridge portion 32 is narrowed can be formed at the same time.
　図２（ｄ）のように、絶縁膜４８を全面堆積した後、リッジ部３２上の絶縁膜４８と、狭幅部４４と後端面１８との間であって、テラス部４６上の絶縁膜４８と、をエッチングする。その後、絶縁膜４８をエッチングした箇所であるリッジ部３２のコンタクト層３６上にレーザダイオード１２用のｐ電極４０Ａを、テラス部４６のコンタクト層３６上にフォトダイオード１４用のｐ電極４０Ｂを形成する。狭幅部４４と前端面１６との間であって、テラス部４６の絶縁膜４８上にパッド部４１を形成する。半導体基板１０裏面には、レーザダイオード１２とフォトダイオード１４とで共通に用いられるｎ電極４２を形成する。これにより、図１に示した実施例１に係る光半導体装置１００が完成する。 As shown in FIG. 2D, after the insulating film 48 is deposited over the entire surface, the insulating film 48 on the ridge portion 32, and between the narrow width portion 44 and the rear end face 18 and on the terrace portion 46. 48 are etched. Thereafter, the p-electrode 40A for the laser diode 12 is formed on the contact layer 36 of the ridge 32 where the insulating film 48 is etched, and the p-electrode 40B for the photodiode 14 is formed on the contact layer 36 of the terrace 46. . A pad portion 41 is formed on the insulating film 48 of the terrace portion 46 between the narrow width portion 44 and the front end face 16. On the back surface of the semiconductor substrate 10, an n-electrode 42 that is commonly used by the laser diode 12 and the photodiode 14 is formed. Thereby, the optical semiconductor device 100 according to the first embodiment shown in FIG. 1 is completed.
　次に、図３及び図４を用いて、実施例１に係る光半導体装置１００の動作について説明する。まず、図３を用いて、レーザダイオード１２が有する活性層２４で誘導放出された光の伝搬について説明する。図３（ａ）は、実施例１に係る光半導体装置１００の上面模式図であり、図３（ｂ）から図３（ｄ）は、図３（ａ）のＡ－Ａ間からＣ－Ｃ間の断面模式図である。なお、図３（ａ）中の矢印は、光が伝搬される方向を表しており、図３（ｂ）から図３（ｄ）中の網線部は、光が伝搬する導波領域を表している。 Next, the operation of the optical semiconductor device 100 according to the first embodiment will be described with reference to FIGS. First, the propagation of light stimulated and emitted by the active layer 24 of the laser diode 12 will be described with reference to FIG. FIG. 3A is a schematic top view of the optical semiconductor device 100 according to the first embodiment. FIGS. 3B to 3D are cross-sectional views taken along the line AA in FIG. FIG. Note that the arrows in FIG. 3A indicate the direction in which light is propagated, and the mesh portion in FIGS. 3B to 3D represents a waveguide region in which light propagates. ing.
　図３（ａ）及び図３（ｂ）のように、活性層２４は屈折率の低い下部クラッド層２２と上部クラッド層２６とに挟まれているため、活性層２４で誘導放出された光は活性層２４近傍に閉じ込められる。また、リッジ部３２下の活性層２４近傍を伝搬する光に対する実効屈折率は、リッジ部３２両側の凹部３４下の活性層２４近傍を伝搬する光に対する実効屈折率より大きい。このため、活性層２４近傍を伝搬する光は、リッジ部３２下の活性層２４近傍に閉じ込められる。 As shown in FIGS. 3A and 3B, the active layer 24 is sandwiched between the lower clad layer 22 and the upper clad layer 26 having a low refractive index. It is confined in the vicinity of the active layer 24. The effective refractive index for light propagating in the vicinity of the active layer 24 under the ridge portion 32 is larger than the effective refractive index for light propagating in the vicinity of the active layer 24 under the recess 34 on both sides of the ridge portion 32. For this reason, light propagating in the vicinity of the active layer 24 is confined in the vicinity of the active layer 24 under the ridge portion 32.
　図３（ａ）及び図３（ｃ）のように、リッジ部３２下の活性層２４近傍を伝搬してきた光が、リッジ部３２の幅が狭くなる狭幅部４４に到達すると、伝搬してきた光の一部はまっすぐに進むことができず、左右に分岐して伝搬するようになる。このように、伝搬してきた光が狭幅部４４で左右に分岐するのは、狭幅部４４で伝搬することのできるモード形状が、狭幅部４４前後の幅広部５０で伝搬することのできるモード形状と比べて変化するためである。 As shown in FIGS. 3A and 3C, the light propagating in the vicinity of the active layer 24 under the ridge portion 32 propagates when reaching the narrow width portion 44 where the width of the ridge portion 32 becomes narrow. Some of the light cannot travel straight, but propagates branching left and right. As described above, the propagating light branches right and left in the narrow portion 44 because the mode shape that can propagate in the narrow portion 44 can propagate in the wide portion 50 before and after the narrow portion 44. This is because it changes compared to the mode shape.
　図３（ａ）及び図３（ｄ）のように、狭幅部４４で左右に分岐された光は、凹部３４下を横断して伝搬し、フォトダイオード１４に導かれる。 As shown in FIGS. 3A and 3D, the light branched right and left by the narrow width portion 44 propagates under the concave portion 34 and is guided to the photodiode 14.
　図４は、半導体基板１０裏面のｎ電極４２は接地させ、レーザダイオード１２用のｐ電極４０Ａに＋２Ｖの電圧を印加させ、フォトダイオード１４用のｐ電極４０Ｂに－１Ｖの電圧を印加させた場合の電界分布（図４中の破線）を示している。図４のように、レーザダイオード１２用のｐ電極４０Ａに＋２Ｖの電圧を印加させて順方向のバイアスを加えることで、ホール５３と電子５５とが再結合して光が誘導放出される。 FIG. 4 shows the case where the n-electrode 42 on the back surface of the semiconductor substrate 10 is grounded, a voltage of + 2V is applied to the p-electrode 40A for the laser diode 12, and a voltage of −1V is applied to the p-electrode 40B for the photodiode 14. The electric field distribution (broken line in FIG. 4) is shown. As shown in FIG. 4, by applying a forward bias by applying a voltage of +2 V to the p-electrode 40A for the laser diode 12, the holes 53 and the electrons 55 are recombined, and light is induced and emitted.
　誘導放出された光は、前述したように、リッジ部３２下の活性層２４近傍を伝搬するが、伝搬する光の一部は狭幅部４４で左右に分岐して伝搬されるようになりフォトダイオード１４に導かれる。フォトダイオード１４では、導かれた光の照射によりホール５３と電子５５とが生じ、ホール５３と電子５５とはフォトダイオード１４用のｐ電極４０Ｂに印加された逆バイアスの電圧（－１Ｖ）によって生じる電界に引かれ、フォトダイオード１４に電流を生じさせる。 As described above, the stimulated emission propagates in the vicinity of the active layer 24 under the ridge portion 32. However, a part of the propagated light branches to the left and right at the narrow width portion 44 and propagates. Guided to the diode 14. In the photodiode 14, holes 53 and electrons 55 are generated by irradiation of the guided light, and the holes 53 and electrons 55 are generated by a reverse bias voltage (−1V) applied to the p-electrode 40 </ b> B for the photodiode 14. Being attracted by the electric field, a current is generated in the photodiode 14.
　以上説明してきたように、実施例１に係る光半導体装置１００は、同一の半導体基板１０上にレーザダイオード１２とフォトダイオード１４とが形成されている。レーザダイオード１２は、下部クラッド層２２と活性層２４と上部クラッド層２６とを含みレーザ光を出射する前端面１６と前端面と反対側の端面である後端面１８との間を延在する半導体層２０を有する。また、レーザダイオード１２は、上部クラッド層２６からなる孤立したリッジ部３２と、リッジ部３２の幅が狭まることによる狭幅部４４とを有する。フォトダイオード１４は、レーザダイオード１２の幅方向両側に形成されている。 As described above, in the optical semiconductor device 100 according to the first embodiment, the laser diode 12 and the photodiode 14 are formed on the same semiconductor substrate 10. The laser diode 12 includes a lower cladding layer 22, an active layer 24, and an upper cladding layer 26, and extends between a front end face 16 that emits laser light and a rear end face 18 that is an end face opposite to the front end face. It has a layer 20. Further, the laser diode 12 has an isolated ridge portion 32 made of the upper clad layer 26 and a narrow portion 44 due to the narrow width of the ridge portion 32. The photodiodes 14 are formed on both sides of the laser diode 12 in the width direction.
　レーザダイオード１２が狭幅部４４を有することで、図３及び図４で説明したように、リッジ部３２下の活性層２４近傍を伝搬する光の一部は狭幅部４４で左右に分岐して伝搬されるようになりフォトダイオード１４に導かれる。これにより、フォトダイオード１４でレーザダイオード１２の光出力を検出することができる。 Since the laser diode 12 has the narrow portion 44, a part of the light propagating in the vicinity of the active layer 24 under the ridge portion 32 branches to the left and right at the narrow portion 44 as described in FIGS. And is guided to the photodiode 14. Thereby, the light output of the laser diode 12 can be detected by the photodiode 14.
　ここで、図５を用いて、狭幅部４４の幅及び長さと光の分岐比との関係を計算したシミュレーションについて説明する。図５（ａ）は、シミュレーションに用いた構造を示す模式図であり、図５（ｂ）は、シミュレーション結果である。図５（ａ）のように、シミュレーションには、リッジ部３２の幅広部５０の幅を１．８μｍ、狭幅部４４の幅をＷμｍ、長さをＤμｍとした構造を用い、Ｗ及びＤを変化させた場合における光の分岐比を計算した。光の分岐比は、リッジ部３２下を真っ直ぐ進む光の割合をＴ、左右に分岐して進む光の割合を１－Ｔ（左側及び右側に分岐して進む光の割合はそれぞれ（１－Ｔ）／２）とした。リッジ部３２下の活性層２４であって光が伝搬する導波領域（図３（ｂ）の網線部）の実効屈折率を３．３７７４８とし、導波領域周辺の実効屈折率を３．３６３１９として計算を行った。 Here, the simulation for calculating the relationship between the width and length of the narrow portion 44 and the light branching ratio will be described with reference to FIG. Fig.5 (a) is a schematic diagram which shows the structure used for simulation, and FIG.5 (b) is a simulation result. As shown in FIG. 5A, the simulation uses a structure in which the width of the wide portion 50 of the ridge portion 32 is 1.8 μm, the width of the narrow portion 44 is W μm, and the length is D μm. The light splitting ratio was calculated when the change was made. The light branching ratio is T for the proportion of light that travels straight under the ridge 32 and 1-T for the proportion of light that branches to the left and right (the proportion of light that branches and proceeds to the left and right is (1-T ) / 2). The effective refractive index of the active layer 24 below the ridge 32 and the waveguide region where light propagates (the meshed portion in FIG. 3B) is 3.37748, and the effective refractive index around the waveguide region is 3. The calculation was performed as 36319.
　図５（ｂ）のように、狭幅部４４の幅Ｗを細くすることで、左右に伝搬する光の割合１－Ｔは大きくなる。また、狭幅部４４の長さＤを長くすることでも、左右に伝搬する光の割合１－Ｔは大きくなる。このように、狭幅部４４の幅Ｗ及び長さＤを変化させることで、狭幅部４４で左右に分岐される光の分岐比が変わるため、所望の分岐比を得るための設計の自由度は大きい。 As shown in FIG. 5B, by reducing the width W of the narrow portion 44, the ratio 1-T of light propagating left and right increases. Further, increasing the length D of the narrow portion 44 also increases the ratio 1-T of the light propagating left and right. Thus, by changing the width W and length D of the narrow width portion 44, the branching ratio of the light branched to the left and right at the narrow width portion 44 changes, so that the freedom of design for obtaining a desired branching ratio is achieved. The degree is great.
　このように、実施例１に係る光半導体装置１００によれば、レーザダイオード１２の光出力を、レーザダイオード１２と同一の半導体基板１０上に形成されたフォトダイオード１４で検出することができる。このため、別個の外付けのフォトダイオードを用意する必要がなく、部品数の増加や組み立て工程の複雑化を抑制でき、コストの増大を抑制できる。 As described above, according to the optical semiconductor device 100 according to the first embodiment, the optical output of the laser diode 12 can be detected by the photodiode 14 formed on the same semiconductor substrate 10 as the laser diode 12. For this reason, it is not necessary to prepare a separate external photodiode, the increase in the number of components and the complexity of the assembly process can be suppressed, and the increase in cost can be suppressed.
　また、図２（ａ）から図２（ｄ）で説明したように、実施例１に係る光半導体装置１００は、リッジ構造を有するレーザダイオードの製造工程と同一工程で製造でき、製造工程が複雑化することがない。したがって、製造工程の工程数の増加によるコストの増大を抑制することができる。 Further, as described with reference to FIGS. 2A to 2D, the optical semiconductor device 100 according to the first embodiment can be manufactured in the same process as the process of manufacturing the laser diode having the ridge structure, and the manufacturing process is complicated. It will not become. Therefore, an increase in cost due to an increase in the number of manufacturing steps can be suppressed.
　図１のように、レーザダイオード１２が有する活性層２４とフォトダイオード１４が有する活性層２４とは、同時に形成されるため接続している。これにより、図３のように、狭幅部４４でリッジ部３２下の活性層２４近傍から左右に分岐された光は、活性層２４内を伝搬してフォトダイオード１４に導かれる。つまり、狭幅部４４で左右に分岐された光は上下方向（半導体基板１０表面に垂直な方向）に広がることがなく、フォトダイオード１４は分岐された光の大部分を受光することができる。このため、フォトダイオード１４は良好な受光効率が得られる。 As shown in FIG. 1, the active layer 24 included in the laser diode 12 and the active layer 24 included in the photodiode 14 are connected because they are formed at the same time. As a result, as shown in FIG. 3, the light branched right and left from the vicinity of the active layer 24 below the ridge portion 32 in the narrow width portion 44 propagates in the active layer 24 and is guided to the photodiode 14. That is, the light branched right and left by the narrow width portion 44 does not spread in the vertical direction (direction perpendicular to the surface of the semiconductor substrate 10), and the photodiode 14 can receive most of the branched light. For this reason, the photodiode 14 can obtain good light receiving efficiency.
　図１のように、フォトダイオード１４は、レーザダイオード１２の両側に設けられている場合が好ましい。レーザダイオード１２の片側の側方にのみフォトダイオード１４が設けられている場合でも、レーザダイオード１２の光出力をフォトダイオード１４で検出することができるが、受光効率を向上させる観点から、レーザダイオード１２の両側にフォトダイオード１４が設けられている場合が好ましい。 As shown in FIG. 1, the photodiodes 14 are preferably provided on both sides of the laser diode 12. Even when the photodiode 14 is provided only on one side of the laser diode 12, the light output of the laser diode 12 can be detected by the photodiode 14, but from the viewpoint of improving the light receiving efficiency, the laser diode 12 It is preferable that photodiodes 14 are provided on both sides.
　図１のように、狭幅部４４の前後の幅広部５０から狭幅部４４へは段差状に幅が狭まる場合が好ましい。これにより、リッジ部３２下の活性層２４近傍を伝搬してきた光の一部を、狭幅部４４で左右に分岐させることをより確実に行うことができる。また、幅広部５０から狭幅部４４になだらかに幅が変化する場合であっても、変化する距離が短い場合は、リッジ部３２下の活性層２４近傍を伝搬してきた光の一部を、狭幅部４４で左右に分岐させることができる。 As shown in FIG. 1, it is preferable that the width narrows in a step shape from the wide portion 50 before and after the narrow portion 44 to the narrow portion 44. As a result, it is possible to more reliably cause a part of the light propagating in the vicinity of the active layer 24 below the ridge portion 32 to be branched left and right by the narrow width portion 44. Further, even when the width gradually changes from the wide portion 50 to the narrow portion 44, when the changing distance is short, a part of the light propagating in the vicinity of the active layer 24 under the ridge portion 32 is The narrow portion 44 can be branched left and right.
　図１のように、フォトダイオード１４用のｐ電極４０Ｂは、狭幅部４４と後端面１８との間のテラス部４６上に形成されている場合が好ましい。後端面１８には、レーザ光に対する高反射膜３８が設けられているため、図３のように、狭幅部４４で左右に分岐して伝搬する光のうち後端面１８で反射した光についてもフォトダイオード１４で検出することができる。これにより、フォトダイオード１４での受光効率をより向上させることができる。また、フォトダイオード１４用のｐ電極４０Ｂが、前端面１６と後端面１８との間のテラス部４６上全面に設けられている場合でもよい。この場合でも、後端面１８で反射した光をフォトダイオード１４で検出することができる。しかしながら、レーザダイオード１２用のｐ電極４０Ａの幅は狭いためパッド部として用いることができないことから、図１のように、ｐ電極４０Ａに接続するパッド部４１は、幅広部分であるテラス部４６上に形成されることが望ましい。したがって、パッド部４１をテラス部４６上に形成し、且つフォトダイオード１４の受光効率を向上させるには、フォトダイオード１４用のｐ電極４０Ｂは、狭幅部４４と後端面１８との間のテラス部４６上に形成されている場合が好ましい。 As shown in FIG. 1, the p-electrode 40B for the photodiode 14 is preferably formed on a terrace portion 46 between the narrow width portion 44 and the rear end face 18. Since the rear end surface 18 is provided with a highly reflective film 38 for laser light, as shown in FIG. It can be detected by the photodiode 14. Thereby, the light reception efficiency in the photodiode 14 can be further improved. Further, the p electrode 40B for the photodiode 14 may be provided on the entire surface of the terrace portion 46 between the front end face 16 and the rear end face 18. Even in this case, the light reflected by the rear end face 18 can be detected by the photodiode 14. However, since the width of the p-electrode 40A for the laser diode 12 is narrow and cannot be used as a pad portion, the pad portion 41 connected to the p-electrode 40A is on the terrace portion 46, which is a wide portion, as shown in FIG. It is desirable to be formed. Therefore, in order to form the pad portion 41 on the terrace portion 46 and improve the light receiving efficiency of the photodiode 14, the p-electrode 40 B for the photodiode 14 has a terrace between the narrow width portion 44 and the rear end face 18. The case where it forms on the part 46 is preferable.
　実施例１においては、レーザダイオード１２が量子ドットレーザである場合を例に説明してきたが、これに限らず、例えば量子井戸レーザ等、量子ドットレーザ以外の半導体レーザの場合でもよい。また、ＤＦＢ（Distributed Feedback）型レーザであってもファブリペロ型レーザであってもよい。これらの場合でも、コストの増大を抑制しつつ、レーザダイオードの光出力をフォトダイオードで検出することが可能な光半導体装置を得ることができる。 In the first embodiment, the case where the laser diode 12 is a quantum dot laser has been described as an example. However, the present invention is not limited to this. For example, a semiconductor laser other than a quantum dot laser such as a quantum well laser may be used. Further, it may be a DFB (Distributed Feedback) type laser or a Fabry-Perot type laser. Even in these cases, it is possible to obtain an optical semiconductor device capable of detecting the light output of the laser diode with the photodiode while suppressing an increase in cost.
　実施例２は、ＢＨ構造（埋め込みヘテロ構造）のレーザダイオードを有する場合の光半導体装置の例である。図６（ａ）は実施例２に係る光半導体装置２００の上面模式図であり、図６（ｂ）から図６（ｄ）は、図６（ａ）のＡ－Ａ間からＣ－Ｃ間の断面模式図である。なお、図６（ａ）中の矢印は、光が伝搬される方向を表しており、図６（ｂ）から図６（ｄ）中の網線部は、光が伝搬する導波領域を表している。 Example 2 is an example of an optical semiconductor device having a laser diode having a BH structure (buried heterostructure). FIG. 6A is a schematic top view of the optical semiconductor device 200 according to the second embodiment, and FIGS. 6B to 6D are diagrams from AA to CC in FIG. 6A. FIG. Note that the arrows in FIG. 6A represent the direction in which light is propagated, and the mesh portion in FIGS. 6B to 6D represents a waveguide region in which light propagates. ing.
　図６（ａ）から図６（ｄ）のように、実施例２に係る光半導体装置２００は、例えばｎ型ＩｎＰ基板からなる同一の半導体基板１０上に、レーザダイオード１２とフォトダイオード１４とが形成されている。フォトダイオード１４は、レーザダイオード１２を挟むように両側方に形成されている。 As shown in FIGS. 6A to 6D, the optical semiconductor device 200 according to the second embodiment includes a laser diode 12 and a photodiode 14 on the same semiconductor substrate 10 made of, for example, an n-type InP substrate. Is formed. The photodiodes 14 are formed on both sides so as to sandwich the laser diode 12.
　レーザダイオード１２及びフォトダイオード１４は共に、半導体基板１０表面上に、例えばｎ型ＩｎＰ層からなる下部クラッド層２２と、ＩｎＧａＡｓＰ－ＭＱＷ（Multiple Quantum Wells）層からなる活性層２４と、ｐ型ＩｎＰ層からなる上部クラッド層２６と、が順次積層された半導体層２０を有する。 Both the laser diode 12 and the photodiode 14 are formed on the surface of the semiconductor substrate 10, for example, a lower cladding layer 22 made of an n-type InP layer, an active layer 24 made of an InGaAsP-MQW (MultipleMultiQuantum Wells) layer, and a p-type InP layer. And an upper clad layer 26 made of a semiconductor layer 20 sequentially stacked.
　レーザダイオード１２は、上部クラッド層２６と活性層２４と下部クラッド層２２とが孤立することで形成された半導体メサ部５２を有する。半導体メサ部５２は、前端面１６と後端面１８との間を延在して形成されている。前端面１６には、出射されるレーザ光の波長に対する低反射膜（ＡＲ膜）３７が形成されていて、後端面１８には、出射されるレーザ光の波長に対する高反射膜（ＨＲ膜）３８が形成されている。半導体メサ部５２の両側には、半導体メサ部５２の側面を覆うようにｎ型ＩｎＰ層からなる埋め込み層５４が形成されている。 The laser diode 12 has a semiconductor mesa portion 52 formed by the upper cladding layer 26, the active layer 24, and the lower cladding layer 22 being isolated. The semiconductor mesa portion 52 is formed to extend between the front end face 16 and the rear end face 18. A low reflection film (AR film) 37 for the wavelength of the emitted laser light is formed on the front end face 16, and a high reflection film (HR film) 38 for the wavelength of the emitted laser light is formed on the rear end face 18. Is formed. On both sides of the semiconductor mesa portion 52, a buried layer 54 made of an n-type InP layer is formed so as to cover the side surface of the semiconductor mesa portion 52.
　半導体メサ部５２上には、ｐ型ＩｎＧａＡｓ層からなるコンタクト層３６が形成され、コンタクト層３６上にレーザダイオード１２用のｐ電極４０Ａが形成されている。半導体基板１０裏面には、レーザダイオード１２とフォトダイオード１４とで共通に用いられるｎ電極４２が形成されている。レーザダイオード１２は、半導体メサ部５２（つまり、下部クラッド層２２と活性層２４と上部クラッド層２６）の幅が一部で狭まる狭幅部４４を有する。狭幅部４４前後の幅広部５０から狭幅部４４へは段差状に幅が狭まっている。 A contact layer 36 made of a p-type InGaAs layer is formed on the semiconductor mesa portion 52, and a p-electrode 40A for the laser diode 12 is formed on the contact layer 36. On the back surface of the semiconductor substrate 10, an n-electrode 42 that is commonly used by the laser diode 12 and the photodiode 14 is formed. The laser diode 12 has a narrow width portion 44 in which the width of the semiconductor mesa portion 52 (that is, the lower cladding layer 22, the active layer 24, and the upper cladding layer 26) is partially reduced. From the wide part 50 before and after the narrow part 44 to the narrow part 44, the width is narrowed stepwise.
　フォトダイオード１４が有する半導体層２０の側面は、埋め込み層５４により覆われている。つまり、レーザダイオード１２が有する活性層２４とフォトダイオード１４が有する活性層２４とは、埋め込み層５４を介して接続されている。レーザダイオード１２の狭幅部４４と後端面１８との間であって、フォトダイオード１４が有する上部クラッド層２６上には、ｐ型ＩｎＧａＡｓ層からなるコンタクト層３６を介してフォトダイオード１４用のｐ電極４０Ｂが形成されている。ｐ電極４０Ｂが形成されていない部分のコンタクト層３６等を覆うように、例えば酸化シリコン膜からなる絶縁膜４８が形成されている。 The side surface of the semiconductor layer 20 included in the photodiode 14 is covered with a buried layer 54. That is, the active layer 24 included in the laser diode 12 and the active layer 24 included in the photodiode 14 are connected via the buried layer 54. On the upper clad layer 26 between the narrow width portion 44 and the rear end face 18 of the laser diode 12 and on the upper cladding layer 26 of the photodiode 14, the p for the photodiode 14 is connected via a contact layer 36 made of a p-type InGaAs layer. An electrode 40B is formed. An insulating film 48 made of, for example, a silicon oxide film is formed so as to cover a portion of the contact layer 36 where the p-electrode 40B is not formed.
　レーザダイオード１２用のｐ電極４０Ａに接続するパッド部４１は、狭幅部４４と前端面１６との間であって、フォトダイオード１４の前方（前端面１６側）に形成された絶縁膜４８上に形成されている。フォトダイオード１４用のｐ電極４０Ｂは、パッド部としても用いられる。 The pad portion 41 connected to the p-electrode 40A for the laser diode 12 is on the insulating film 48 formed between the narrow width portion 44 and the front end face 16 and in front of the photodiode 14 (front end face 16 side). Is formed. The p-electrode 40B for the photodiode 14 is also used as a pad portion.
　次に、図７（ａ）から図７（ｄ）を用い、実施例２に係る光半導体装置２００の製造方法を説明する。図７（ａ）、図７（ｂ）及び図７（ｄ）は、図７（ａ）のＣ－Ｃ間に相当する断面模式図であり、図７（ｃ）は、図７（ａ）のＢ－Ｂ間に相当する断面模式図である。図７（ａ）のように、例えばＭＢＥ（Molecular Beam Epitaxy）法を用い、半導体基板１０表面上に、下部クラッド層２２、活性層２４、上部クラッド層２６、及びコンタクト層３６を順次堆積する。 Next, a method for manufacturing the optical semiconductor device 200 according to the second embodiment will be described with reference to FIGS. 7A to 7D. 7A, 7B, and 7D are schematic cross-sectional views corresponding to the line CC in FIG. 7A, and FIG. 7C is a cross-sectional view of FIG. It is a cross-sectional schematic diagram equivalent to between BB. As shown in FIG. 7A, the lower clad layer 22, the active layer 24, the upper clad layer 26, and the contact layer 36 are sequentially deposited on the surface of the semiconductor substrate 10 by using, for example, MBE (Molecular Beam Epitaxy) method.
　図７（ｂ）及び図７（ｃ）のように、コンタクト層３６上に形成したマスク層をマスクとして、コンタクト層３６と上部クラッド層２６と活性層２４と下部クラッド層２２とを、例えばドライエッチング法を用いてエッチングする。これにより、レーザダイオード１２となる部分において、孤立した上部クラッド層２６と活性層２４と下部クラッド層２２とからなる半導体メサ部５２が形成される。また、半導体メサ部５２の幅が狭まる狭幅部４４も同時に形成することができる。 7B and 7C, using the mask layer formed on the contact layer 36 as a mask, the contact layer 36, the upper cladding layer 26, the active layer 24, and the lower cladding layer 22 are, for example, dried. Etching is performed using an etching method. As a result, a semiconductor mesa portion 52 composed of the isolated upper clad layer 26, active layer 24, and lower clad layer 22 is formed in the portion to become the laser diode 12. Further, the narrow width portion 44 where the width of the semiconductor mesa portion 52 is narrowed can be formed at the same time.
　図７（ｄ）のように、半導体メサ部５２を形成するためにエッチングした部分に、埋め込み層５４を埋め込む。次いで、絶縁膜４８を全面堆積した後、半導体メサ部５２上の絶縁膜４８と、狭幅部４４と後端面１８との間であって、フォトダイオード１４となるべき部分のコンタクト層３６上の絶縁膜４８と、をエッチングする。その後、絶縁膜４８をエッチングした箇所にレーザダイオード１２用のｐ電極４０Ａとフォトダイオード１４用のｐ電極４０Ｂとを形成する。狭幅部４４と前端面１６との間であってフォトダイオード１４の前方の絶縁膜４８上にパッド部４１を形成する。半導体基板１０裏面にレーザダイオード１２とフォトダイオード１４とで共通して用いられるｎ電極４２を形成する。これにより、図６に示した実施例２に係る光半導体装置２００が完成する。 As shown in FIG. 7D, a buried layer 54 is buried in a portion etched to form the semiconductor mesa portion 52. Next, after the entire surface of the insulating film 48 is deposited, the insulating film 48 on the semiconductor mesa portion 52, the portion between the narrow width portion 44 and the rear end surface 18, on the contact layer 36 that is to become the photodiode 14. The insulating film 48 is etched. Thereafter, a p-electrode 40A for the laser diode 12 and a p-electrode 40B for the photodiode 14 are formed at the locations where the insulating film 48 has been etched. A pad portion 41 is formed on the insulating film 48 between the narrow width portion 44 and the front end face 16 and in front of the photodiode 14. An n-electrode 42 that is used in common by the laser diode 12 and the photodiode 14 is formed on the back surface of the semiconductor substrate 10. Thereby, the optical semiconductor device 200 according to Example 2 shown in FIG. 6 is completed.
　実施例２に係る光半導体装置２００によれば、レーザダイオード１２は、半導体メサ部５２の幅が狭まることによる狭幅部４４を有する。このため、図６（ａ）から図６（ｄ）のように、実施例１で説明した理由と同様の理由により、活性層２４近傍を伝搬する光の一部は狭幅部４４で左右に分岐して伝搬されるようになりフォトダイオード１４に導かれる。これにより、フォトダイオード１４でレーザダイオード１２の光出力を検出することができる。 According to the optical semiconductor device 200 according to the second embodiment, the laser diode 12 has the narrow portion 44 due to the narrow width of the semiconductor mesa portion 52. For this reason, as shown in FIGS. 6A to 6D, a part of the light propagating in the vicinity of the active layer 24 is left and right at the narrow portion 44 for the same reason as described in the first embodiment. The light is branched and propagated and guided to the photodiode 14. Thereby, the light output of the laser diode 12 can be detected by the photodiode 14.
　したがって、実施例２によれば、実施例１と同様に、別個の外付けのフォトダイオードを用意する必要がないため、部品数の増加や組み立て工程の複雑化を抑制でき、コストの増大を抑制できる。 Therefore, according to the second embodiment, as in the first embodiment, it is not necessary to prepare a separate external photodiode. Therefore, it is possible to suppress an increase in the number of components and a complicated assembly process, thereby suppressing an increase in cost. it can.
　なお、実施例２では、半導体メサ部５２の幅（上部クラッド層２６と活性層２４と下部クラッド層２２との幅）が狭まることで狭幅部４４が形成されている場合を示したが、これに限られず、少なくとも上部クラッド層２６の幅が狭くなることで狭幅部４４が形成されていればよい。この場合でも、活性層２４近傍を伝搬する光の一部を狭幅部４４で左右に分岐させることができる。しかしながら、図７（ａ）から図７（ｄ）で説明したように、半導体メサ部５２の幅を狭めることで狭幅部４４を形成する場合は、ＢＨ構造（埋め込みヘテロ構造）を有するレーザダイオードの製造工程と同一工程で製造でき、製造工程が複雑化することがない。したがって、製造工程の工程数の増加によるコストの増加を抑制できるため、実施例２に係る光半導体装置２００のように、半導体メサ部５２全層の幅が狭まることで狭幅部４４が形成されている場合が好ましい。 In Example 2, the case where the narrow width portion 44 is formed by narrowing the width of the semiconductor mesa portion 52 (the width of the upper cladding layer 26, the active layer 24, and the lower cladding layer 22) is shown. However, the present invention is not limited to this, and it is sufficient that the narrow portion 44 is formed by at least the width of the upper cladding layer 26 being narrowed. Even in this case, part of the light propagating in the vicinity of the active layer 24 can be branched left and right by the narrow width portion 44. However, as described with reference to FIGS. 7A to 7D, when the narrow width portion 44 is formed by narrowing the width of the semiconductor mesa portion 52, the laser diode having the BH structure (buried heterostructure). It can be manufactured in the same process as the manufacturing process, and the manufacturing process is not complicated. Therefore, since an increase in cost due to an increase in the number of manufacturing steps can be suppressed, the narrow portion 44 is formed by reducing the width of the entire semiconductor mesa portion 52 as in the optical semiconductor device 200 according to the second embodiment. Is preferred.
　図６のように、レーザダイオード１２が有する活性層２４とフォトダイオードが有する活性層２４とは、レーザダイオード１２が有する半導体メサ部５２の側面を覆うように形成された埋め込み層５４を介して接続されている。これにより、狭幅部４４で活性層２４近傍から左右に分岐された光は、埋め込み層５４内を伝搬してフォトダイオード１４に導かれることができる。 As shown in FIG. 6, the active layer 24 included in the laser diode 12 and the active layer 24 included in the photodiode are connected via a buried layer 54 formed so as to cover the side surface of the semiconductor mesa portion 52 included in the laser diode 12. Has been. Thereby, the light branched right and left from the vicinity of the active layer 24 in the narrow width portion 44 can propagate through the buried layer 54 and be guided to the photodiode 14.
　実施例２においては、レーザダイオード１２が量子井戸レーザである場合を例に説明したが、これに限らず、例えば、実施例１のような量子ドットレーザ等、量子井戸レーザ以外の半導体レーザの場合でもよい。また、ＤＦＢ型レーザであってもファブリペロ型レーザであってもよい。これらの場合でも、コストの増大を抑制しつつ、レーザダイオードの光出力をフォトダイオードで検出することが可能な光半導体装置を得ることができる。 In the second embodiment, the case where the laser diode 12 is a quantum well laser has been described as an example. However, the present invention is not limited to this. For example, in the case of a semiconductor laser other than the quantum well laser, such as a quantum dot laser as in the first embodiment. But you can. Further, it may be a DFB type laser or a Fabry-Perot type laser. Even in these cases, it is possible to obtain an optical semiconductor device capable of detecting the light output of the laser diode with the photodiode while suppressing an increase in cost.
　実施例１および実施例２において、レーザダイオード１２は、リッジ部３２または半導体メサ部５２の幅が一部で狭まる狭幅部４４を有する場合を例に示したが、この場合に限られず、例えば、リッジ部３２または半導体メサ部５２の幅が一部で広がる場合でもよい。このように、レーザダイオード１２が、リッジ部３２または半導体メサ部５２の幅が変化する幅変化部を有することで、リッジ部３２下または半導体メサ部５２の活性層２４近傍を伝搬する光の一部は幅変化部で左右に漏れて伝搬するようになる。これにより、フォトダイオード１４でレーザダイオード１２の光出力を検出することが可能となる。また、幅変化部へは段差状に幅が変化する場合が好ましい。 In the first embodiment and the second embodiment, the laser diode 12 has been described as an example in which the ridge portion 32 or the semiconductor mesa portion 52 has the narrow width portion 44 in which the width is partially reduced. The ridge portion 32 or the semiconductor mesa portion 52 may be partially enlarged. As described above, the laser diode 12 has the width changing portion in which the width of the ridge portion 32 or the semiconductor mesa portion 52 changes, so that one of the light propagating under the ridge portion 32 or in the vicinity of the active layer 24 of the semiconductor mesa portion 52 can be obtained. The part leaks to the left and right at the width changing part and propagates. As a result, the optical output of the laser diode 12 can be detected by the photodiode 14. Further, it is preferable that the width changes in a stepped manner to the width changing portion.
　実施例３は、実施例１に係る光半導体装置１００を備える光モジュールの例である。図８は、実施例３に係る光モジュール３００の構成を示すブロック図である。図８のように、実施例３に係る光モジュール３００は、レーザダイオード１２とフォトダイオード１４とを備える実施例１に係る光半導体装置１００、駆動回路５６、ＡＰＣ（Auto Power Control）回路５８、及び入力部６０を有する。入力部６０は、外部から送信データ信号６２を受信し、駆動回路５６に送信データ信号を出力する。駆動回路５６は、制御信号６４に基づき駆動電流６６を制御しつつ、レーザダイオード１２に駆動電流６６を出力する。レーザダイオード１２は、駆動電流６６に応じた光出力でレーザ光６８を出射する。フォトダイオード１４は、実施例１で説明したようにレーザダイオード１２の活性層２４で誘導放出された光の一部７０からレーザダイオード１２の光出力を検出し、光出力に応じたモニタ電流７２をＡＰＣ回路５８に出力する。ＡＰＣ回路５８は、モニタ電流７２と基準電流とを比較し、制御信号６４を駆動回路５６に出力する。 Example 3 is an example of an optical module including the optical semiconductor device 100 according to Example 1. FIG. FIG. 8 is a block diagram illustrating the configuration of the optical module 300 according to the third embodiment. As shown in FIG. 8, the optical module 300 according to the third embodiment includes an optical semiconductor device 100 according to the first embodiment that includes the laser diode 12 and the photodiode 14, a drive circuit 56, an APC (Auto Power Control) circuit 58, and An input unit 60 is included. The input unit 60 receives a transmission data signal 62 from the outside and outputs a transmission data signal to the drive circuit 56. The drive circuit 56 outputs the drive current 66 to the laser diode 12 while controlling the drive current 66 based on the control signal 64. The laser diode 12 emits a laser beam 68 with an optical output corresponding to the drive current 66. As described in the first embodiment, the photodiode 14 detects the light output of the laser diode 12 from a part 70 of the light stimulated and emitted by the active layer 24 of the laser diode 12, and generates a monitor current 72 corresponding to the light output. The data is output to the APC circuit 58. The APC circuit 58 compares the monitor current 72 with the reference current and outputs a control signal 64 to the drive circuit 56.
　このように、実施例３に係る光モジュール３００によれば、フォトダイオード１４でレーザダイオード１２の光出力を検出し、検出した光出力をＡＰＣ回路５８により駆動回路５６にフィードバックする。駆動回路５６は、ＡＰＣ回路５８によりフィードバックされた制御信号６４に基づき駆動電流６６を制御して、レーザダイオード１２に駆動電流６６を出力する。これにより、レーザダイオード１２の光出力を一定に保つことができる。 As described above, according to the optical module 300 according to the third embodiment, the optical output of the laser diode 12 is detected by the photodiode 14, and the detected optical output is fed back to the drive circuit 56 by the APC circuit 58. The drive circuit 56 controls the drive current 66 based on the control signal 64 fed back by the APC circuit 58 and outputs the drive current 66 to the laser diode 12. Thereby, the light output of the laser diode 12 can be kept constant.
　また、実施例３に係る光モジュール３００は、実施例１に係る光半導体装置１００を備えているため、レーザダイオードと別個の外付けのフォトダイオードを用意する必要がなく、コストの増大を抑制できる。なお、実施例３に係る光モジュール３００は、実施例１に係る光半導体装置１００を備えている場合を例に示したが、実施例２に係る光半導体装置２００を備えている場合でもよい。この場合でも、別個の外付けのフォトダイオードを用意する必要がないため、コストの増大を抑制できる。 Further, since the optical module 300 according to the third embodiment includes the optical semiconductor device 100 according to the first embodiment, it is not necessary to prepare an external photodiode separate from the laser diode, and an increase in cost can be suppressed. . In addition, although the case where the optical module 300 according to the third embodiment includes the optical semiconductor device 100 according to the first embodiment is illustrated as an example, the optical module 300 according to the third embodiment may include the optical semiconductor device 200 according to the second embodiment. Even in this case, since it is not necessary to prepare a separate external photodiode, an increase in cost can be suppressed.
　以上、本発明の好ましい実施例について詳述したが、本発明は係る特定の実施例に限定されるものではなく、特許請求の範囲に記載された本発明の要旨の範囲内において、種々の変形・変更が可能である。 The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims.・ Change is possible.

Claims (10)

  1. 　半導体基板上に順次積層された下部クラッド層と活性層と前記下部クラッド層と反対の導電型の上部クラッド層とを含む半導体層を有し、レーザ光を出射する前端面と前記前端面と反対側の端面である後端面との間を前記半導体層が延在して形成されたレーザダイオードと、
    　前記半導体基板上に前記レーザダイオードの幅方向に形成され、前記レーザダイオードの光出力を検出するフォトダイオードと、を具備し、
    　前記レーザダイオードは、前記半導体層のうちの少なくとも前記上部クラッド層の幅が変化する幅変化部を有することを特徴とする光半導体装置。     A semiconductor layer including a lower clad layer, an active layer, and an upper clad layer having a conductivity type opposite to the lower clad layer, which are sequentially stacked on a semiconductor substrate, and has a front end face that emits laser light and a front face opposite to the front end face A laser diode formed by extending the semiconductor layer between a rear end face that is an end face on the side;
    A photodiode formed on the semiconductor substrate in a width direction of the laser diode and detecting a light output of the laser diode;
    The laser diode has a width changing portion in which a width of at least the upper cladding layer of the semiconductor layer changes.
  2. 　前記幅変化部は、前記半導体層のうちの少なくとも前記上部クラッド層の幅が狭まる狭幅部であることを特徴とする請求項１記載の光半導体装置。 2. The optical semiconductor device according to claim 1, wherein the width changing portion is a narrow width portion where a width of at least the upper cladding layer of the semiconductor layer is narrowed.
  3. 　前記レーザダイオードは、孤立した前記上部クラッド層からなるリッジ部を有し、
    　前記幅変化部は、前記リッジ部の幅が変化することにより形成されていることを特徴とする請求項１または２記載の光半導体装置。     The laser diode has a ridge portion composed of the isolated upper clad layer,
    3. The optical semiconductor device according to claim 1, wherein the width changing portion is formed by changing a width of the ridge portion.
  4. 　前記フォトダイオードは、前記半導体基板上に順次積層された下部クラッド層と活性層と前記下部クラッド層と反対の導電型の上部クラッド層とを有し、
    　前記フォトダイオードが有する前記活性層と前記レーザダイオードが有する前記活性層とは接続していることを特徴とする請求項３記載の光半導体装置。     The photodiode has a lower clad layer, an active layer, and an upper clad layer of a conductivity type opposite to the lower clad layer, which are sequentially stacked on the semiconductor substrate,
    4. The optical semiconductor device according to claim 3, wherein the active layer of the photodiode is connected to the active layer of the laser diode.
  5. 　前記レーザダイオードは、前記下部クラッド層と前記活性層と前記上部クラッド層とが孤立した半導体メサ部を有し、
    　前記幅変化部は、前記半導体メサ部の幅が変化することにより形成されていることを特徴とする請求項１または２記載の光半導体装置。     The laser diode has a semiconductor mesa portion in which the lower cladding layer, the active layer, and the upper cladding layer are isolated,
    3. The optical semiconductor device according to claim 1, wherein the width changing portion is formed by changing a width of the semiconductor mesa portion.
  6. 　前記フォトダイオードは、前記半導体基板上に順次積層された下部クラッド層と活性層と前記下部クラッド層と反対の導電型の上部クラッド層とを有し、
    　前記フォトダイオードが有する活性層と前記レーザダイオードが有する活性層とは、前記半導体メサ部の側面を覆うように形成された埋め込み層を介して接続していることを特徴とする請求項５記載の光半導体装置。     The photodiode has a lower clad layer, an active layer, and an upper clad layer of a conductivity type opposite to the lower clad layer, which are sequentially stacked on the semiconductor substrate,
    6. The active layer of the photodiode and the active layer of the laser diode are connected via a buried layer formed so as to cover a side surface of the semiconductor mesa portion. Optical semiconductor device.
  7. 　前記幅変化部へは段差状に幅が変化することを特徴とする請求項１から６のいずれか一項記載の光半導体装置。 The optical semiconductor device according to any one of claims 1 to 6, wherein a width of the width changing portion changes stepwise.
  8. 　前記フォトダイオードは、前記レーザダイオードを挟むように両側に設けられていることを特徴とする請求項１から７のいずれか一項記載の光半導体装置。 8. The optical semiconductor device according to claim 1, wherein the photodiode is provided on both sides so as to sandwich the laser diode.
  9. 　前記前端面に設けられた前記レーザ光に対する低反射膜と、前記後端面に設けられた前記レーザ光に対する高反射膜と、を具備し、
    　前記幅変化部と前記後端面との間に、前記フォトダイオードに電圧を印加するための電極が設けられていることを特徴とする請求項１から８のいずれか一項記載の光半導体装置。     A low reflection film for the laser light provided on the front end face, and a high reflection film for the laser light provided on the rear end face,
    9. The optical semiconductor device according to claim 1, wherein an electrode for applying a voltage to the photodiode is provided between the width changing portion and the rear end face.
  10. 　請求項１から９のいずれか一項記載の光半導体装置と、
    　前記フォトダイオードで検出された前記レーザダイオードの光出力のフィードバックを受けて前記レーザダイオードに駆動電流を供給する駆動回路と、を具備することを特徴とする光モジュール。     An optical semiconductor device according to any one of claims 1 to 9,
    An optical module comprising: a drive circuit that receives a feedback of an optical output of the laser diode detected by the photodiode and supplies a drive current to the laser diode.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10223966A (en) * 1997-01-31 1998-08-21 Sharp Corp Gain coupled distributed feedback semiconductor laser
JP2003163415A (en) * 2002-12-06 2003-06-06 Nichia Chem Ind Ltd Nitride semiconductor light emitting element
JP2005228943A (en) * 2004-02-13 2005-08-25 Opnext Japan Inc Semiconductor optical element and optical communication module employing it
JP2006286810A (en) * 2005-03-31 2006-10-19 Fujitsu Ltd Semiconductor device
JP2007081196A (en) * 2005-09-15 2007-03-29 Sony Corp Semiconductor laser device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10223966A (en) * 1997-01-31 1998-08-21 Sharp Corp Gain coupled distributed feedback semiconductor laser
JP2003163415A (en) * 2002-12-06 2003-06-06 Nichia Chem Ind Ltd Nitride semiconductor light emitting element
JP2005228943A (en) * 2004-02-13 2005-08-25 Opnext Japan Inc Semiconductor optical element and optical communication module employing it
JP2006286810A (en) * 2005-03-31 2006-10-19 Fujitsu Ltd Semiconductor device
JP2007081196A (en) * 2005-09-15 2007-03-29 Sony Corp Semiconductor laser device

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