Semiconductor laser device and method for manufacturing semiconductor laser device

Abstract

The embodiment of the invention relates to the technical field of laser devices, and discloses a semiconductor laser device and a manufacturing method of the semiconductor laser device, the semiconductor laser device comprises an active module, a passive waveguide and a ridge waveguide, the active module comprises a quantum well active layer, the quantum well active layer is used for emitting laser, and the passive waveguide is used for emitting light; the passive waveguide surrounds the outer side of the active module in the circumferential direction, the ridge waveguide is connected with the top face of the second conduction part active module and the top face of the second conduction part passive waveguide, the second conduction part ridge waveguide extends in the laser emitting direction, and the second conduction part ridge waveguide comprises a first conduction part and a second conduction part which are connected. The ridge width of one end, close to the second conduction part first conduction part, of the second conduction part is gradually increased in the laser emission direction and is larger than the ridge width of the second conduction part first conduction part, the second conduction part is located on the light emitting side of the second conduction part active module, and the anti-reflection capacity of the semiconductor laser device is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of laser devices, and in particular, to a semiconductor laser device and a method for manufacturing a semiconductor laser device. Background Art

[0002] When the laser emitted by a semiconductor laser device, such as a laser, passes through a lens, an optical fiber end, and other devices, a portion of the laser will be reflected, which will affect the semiconductor laser device. In related technologies, it is usually necessary to set an isolator between the semiconductor laser device and the optical fiber to reduce the impact of the reflected light on the semiconductor laser device. The isolator accounts for a large proportion of the overall optical module cost, which increases the cost of the optical module. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] To this end, a first aspect of the present invention provides a semiconductor laser device.

[0005] A second aspect of the present invention provides a method for manufacturing a semiconductor laser device.

[0006] In view of this, according to the first aspect of the technical solution of the present application, a semiconductor laser device is proposed, the semiconductor laser device comprising: an active module, a passive waveguide and a ridge waveguide, the active module comprising a quantum well active layer, the quantum well active layer being used to emit laser, the passive waveguide surrounding the outside of the active module along the circumferential direction, the ridge waveguide being connected to the top surfaces of the second conduction part active module and the second conduction part passive waveguide, the second conduction part ridge waveguide extending along the emission direction of the laser, the second conduction part ridge waveguide comprising a first conduction part and a second conduction part connected to each other, the ridge width of the second conduction part at one end of the second conduction part close to the first conduction part of the second conduction part gradually increases along the emission direction of the laser and is greater than the ridge width of the first conduction part of the second conduction part, the second conduction part is located at the light emitting side of the second conduction part active module, and the second conduction part is opposite to the second conduction part passive waveguide.

[0007] In some technical solutions provided in the present application, optionally, the active module also includes: an upper waveguide layer, a lower waveguide layer, a grating layer and a current limiting layer, the upper waveguide layer is connected to the top surface of the quantum well active layer, the lower waveguide layer is connected to the bottom surface of the quantum well active layer, the grating layer is connected to the bottom surface of the lower waveguide layer, and the current limiting layer is respectively connected to the top surface of the upper waveguide layer and the ridge waveguide.

[0008] In some technical solutions provided in the present application, optionally, the semiconductor laser device further includes: an etch stop layer and a second filling layer, the etch stop layer is connected to the top surface of the active module and the passive waveguide, and the second filling layer is connected to the top surface of the etch stop layer. The ridge waveguide includes: a first filling layer, the first filling layer is connected to the top surface of the etch stop layer, the material of the second filling layer is the same as that of the first filling layer, and is located on both sides of the first filling layer, the second filling layers on both sides respectively form processing grooves with the first filling layer, and the first filling layer constitutes a first conductive part and a second conductive part.

[0009] In some technical solutions provided in the present application, optionally, the ridge waveguide further includes: a first contact layer, the first contact layer is connected to the top surface of the first filling layer, and the two ends of the first contact layer along the laser emission direction are respectively contracted inward to form an insulating space, and the insulating spaces on both sides are respectively opposite to the passive waveguide. The semiconductor laser device also includes: a second contact layer, an insulating layer and a metal layer, the second contact layer is connected to the top surface of the second filling layer, the material of the second contact layer is the same as that of the first contact layer, the insulating layer is connected to the outer end face of the ridge waveguide, a contact window is provided on the insulating layer, the contact window avoids the first contact layer, the metal layer covers the ridge waveguide and the insulating layer, and the metal layer forms an ohmic contact with the first contact layer.

[0010] In some technical solutions provided in the present application, optionally, the semiconductor laser device also includes: a buffer layer and a substrate layer, the buffer layer is connected to the bottom surface of the active module, the substrate layer is connected to the bottom surface of the buffer layer, the buffer layer and the substrate layer are made of the same material, the etch stop layer and the buffer layer extend circumferentially out of the active module and form a accommodating space, and the passive waveguide is located in the accommodating space.

[0011] The second technical solution of the present application provides a method for manufacturing a semiconductor laser device, which is used to manufacture the semiconductor laser device provided by any one of the above-mentioned first technical solutions, and the method for manufacturing a semiconductor laser device comprises: epitaxially growing a buffer layer on the top surface of a substrate layer; growing an active module on the top surface of the buffer layer; removing part of the outer end of the active module along the circumferential direction to form an accommodation space; growing a passive waveguide in the accommodation space; and manufacturing a ridge waveguide on the top surfaces of the passive waveguide and the active module.

[0012] In some technical solutions provided in the present application, optionally, the step of growing an active module on the top surface of the buffer layer specifically includes: growing a grating layer on the top surface of the buffer layer; growing a lower waveguide layer on the top surface of the grating layer; growing a quantum well active layer on the top surface of the lower waveguide layer; growing an upper waveguide layer on the top surface of the quantum well active layer; and growing a current limiting layer on the top surface of the upper waveguide layer.

[0013] In some technical solutions provided in the present application, optionally, the step of manufacturing a ridge waveguide on the top surface of the passive waveguide and the active module specifically includes: growing an etch stop layer on the top surface of the passive waveguide and the active module; growing a filling layer on the top surface of the etch stop layer; growing a contact layer on the top surface of the filling layer; processing two processing grooves on the filling layer and the contact layer to form a first filling layer and a second filling layer, as well as a first contact layer prototype and a second contact layer; removing the first contact layer prototype above the passive waveguide, processing an insulating space, and forming a first contact layer.

[0014] In some technical solutions provided in the present application, optionally, after the step of processing the insulating space, it also includes: growing an insulating layer on the outside of the ridge waveguide; removing the insulating layer above the first contact layer to process a contact window; depositing a covering metal layer on top of the first contact layer and the insulating layer; and cutting the metal layer.

[0015] In some technical solutions provided in the present application, optionally, before the step of removing the insulating layer above the first contact layer, the method further includes: removing the insulating layer of a preset width at both ends of the insulating layer in a direction perpendicular to the laser emission. And / or after the step of cutting the metal layer, the method further includes: grinding and polishing the substrate layer to process the thickness of the semiconductor laser device to a preset thickness; and depositing metal on the bottom surface of the substrate layer.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects:

[0017] By setting up mutually coordinated trumpet-shaped ridge waveguides and passive waveguides, after the reflected light is reflected to the end face of the semiconductor laser device, it needs to pass through a section composed of the passive waveguide and the trumpet-shaped ridge waveguide before entering the quantum well active layer. In this section, the reflected light is significantly reduced in mode coupling efficiency of the light wave due to the shrinkage of the width of the ridge waveguide from wide to narrow, and the reverse transmittance is reduced, thereby reducing the reflected light entering the quantum well active layer, improving the light field stability in the resonant cavity, and enhancing the anti-reflection ability of the semiconductor laser device, meeting the anti-reflection requirements of the semiconductor laser device, removing the isolator, and greatly reducing the production cost of the overall optical module. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0019] Figure 1 One of the structural schematic diagrams of a semiconductor laser device according to an embodiment of the present application;

[0020] Figure 2 The second structural schematic diagram of a semiconductor laser device according to an embodiment of the present application;

[0021] Figure 3 The third structural schematic diagram of a semiconductor laser device according to an embodiment of the present application;

[0022] Figure 4 A schematic flow chart of a method for manufacturing a semiconductor laser device according to an embodiment of the present application.

[0023] in, Figures 1 to 4 The corresponding relationship between the reference numerals and the component names is as follows:

[0024] 10 semiconductor laser device, 100 active module, 110 current limiting layer, 120 upper waveguide layer, 130 quantum well active layer, 140 lower waveguide layer, 150 grating layer, 200 passive waveguide, 300 ridge waveguide, 310 first conduction part, 320 second conduction part, 330 first filling layer, 340 first contact layer, 410 etch stop layer, 420 second filling layer, 430 second contact layer, 440 insulating space, 450 processing groove, 500 insulating layer, 600 buffer layer, 700 substrate layer, 800 accommodation space, 900 metal layer. DETAILED DESCRIPTION

[0025] In order to better understand the above-mentioned technical scheme, the technical scheme of the embodiments of the present application is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical scheme of the embodiments of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments may be combined with each other.

[0026] The first embodiment of the present application provides a semiconductor laser device 10, such as Figure 1 and Figure 2As shown, the semiconductor laser device 10 includes: an active module 100, a passive waveguide 200 and a ridge waveguide 300. The active module 100 includes a quantum well active layer 130, and the quantum well active layer 130 is used to emit laser light. The passive waveguide 200 surrounds the outer side of the active module 100 along the circumferential direction. The ridge waveguide 300 is connected to the top surface of the second conduction part active module 100 and the second conduction part passive waveguide 200. The second conduction part ridge waveguide 300 extends along the emission direction of the laser light. The conducting part ridge waveguide 300 includes a first conducting part 310 and a second conducting part 320 connected to each other. The ridge width of the second conducting part 320 at one end close to the second conducting part 310 gradually increases along the emission direction of the laser and is greater than the ridge width of the second conducting part 310. The second conducting part 320 is located at the light emitting side of the second conducting part active module 100, and the second conducting part 320 is opposite to the second conducting part passive waveguide 200.

[0027] In this embodiment, the electrons in the quantum well active layer 130 are in an unstable high-energy state. The electrons quickly transition to a low-energy state and release photons, generating an initial light field. The photon conduction band electrons absorb and transition, emitting two photons, forming stimulated radiation. The high energy level when the conduction band electron state density is higher continuously generates stimulated radiation, and the light field is enhanced, enabling the quantum well active layer 130 to emit laser light to the outside.

[0028] The quantum well active layer 130 can be InAlGaAsMQWs (Multi-Quantum Wells). The quantum well active layer 130 of the active module 100 is the location where photons and gain are generated. It is composed of multiple barriers and wells (high and low bandgap widths) to form a strained quantum well structure, which can effectively increase the light confinement factor, making the output power of the semiconductor laser device 10 larger, and at the same time can also improve the differential gain of the semiconductor laser device 10 and improve the modulation characteristics of the semiconductor laser device 10.

[0029] Figure 1 and Figure 2 In the figure, the arrow at the X position points to the emission direction of the laser, and the arrow at the R position points to the circumference of the active module 100. The passive waveguide 200 surrounds the outer periphery of the active module 100 and encloses a part of the outer end of the semiconductor laser device 10. The height of the active module 100 is the same as the height of the passive waveguide 200. The passive waveguide 200 can be InGaAsP PWS (passive waveguides). After the chip is naturally cleaved, the end face is the passive waveguide 200, which avoids the end face of the Russian harmonic recombination and material oxidation, greatly improving the reliability of the conductor laser device. At the same time, the passive waveguide 200 does not constitute the resonant cavity of the conductor laser device, and the width change of the ridge waveguide 300 will not cause the generation of high-order modes.

[0030] The ridge waveguide 300 is located on the top of the active module 100 and the passive waveguide 200 and extends along the emission direction of the laser. The end faces on both sides of the ridge waveguide 300 are flush with the outer end faces on both sides of the passive waveguide 200, and the ridge waveguide 300 bulges upward. The ridge waveguide 300 includes a first conductive portion 310 and a second conductive portion 320 connected to each other. Figure 2 D is the ridge width. At the end of the second conducting part 320 close to the first conducting part 310, the ridge width gradually increases along the laser emission direction and is greater than the ridge width of the first conducting part 310. The ridge width of the other end of the second conducting part 320 remains the same. The second conducting part 320 is located outside the laser emitting end face of the active module 100, so that the ridge waveguide 300 forms a trumpet-shaped waveguide structure with an expanded width at one end, and the expanded position is located above the passive waveguide 200. The trumpet opening end of the ridge waveguide 300 faces the laser emission end face and cooperates with the passive waveguide 200. The ridge waveguide 300 realizes lateral control of photons and carriers through a lower equivalent refractive index, limits the generated laser transmission, and makes the laser emit from the end face.

[0031] Exemplarily, the length of the ridge waveguide 300 is 20um to 40um, the ridge width of the first conductive part 310 is 2um, the ridge width of the light-emitting end of the second conductive part 320 is 4um to 6um, and the side wall of the connecting end of the second conductive part 320 is a slope, and the expansion angle of the slope relative to the side wall of the first conductive part 310 is 30° to 50°.

[0032] It should be noted that after the laser is emitted from the quantum well active layer 130 , part of the laser is reflected and returns to the end face of the semiconductor laser device 10 , and enters the quantum well active layer 130 , affecting the stability of the light field in the resonant cavity.

[0033] By setting up the trumpet-shaped ridge waveguide 300 and the passive waveguide 200 that cooperate with each other, the reflected light needs to pass through a section composed of the passive waveguide 200 and the trumpet-shaped ridge waveguide 300 after being reflected to the end face of the semiconductor laser device 10 before entering the quantum well active layer 130. In this section, the reflected light is significantly reduced in mode coupling efficiency of the light wave due to the shrinkage of the width of the ridge waveguide 300 from wide to narrow, and the reverse transmittance is reduced, thereby reducing the reflected light entering the quantum well active layer 130, improving the light field stability in the resonant cavity, and enhancing the anti-reflection ability of the semiconductor laser device 10, meeting the anti-reflection requirements of the semiconductor laser device 10, removing the isolator, and greatly reducing the production cost of the overall optical module.

[0034] In some embodiments provided in this application, Figure 1As shown, optionally, the active module 100 further includes: an upper waveguide layer 120, a lower waveguide layer 140, a grating layer 150 and a current limiting layer 110, the upper waveguide layer 120 is connected to the top surface of the quantum well active layer 130, the lower waveguide layer 140 is connected to the bottom surface of the quantum well active layer 130, the grating layer 150 is connected to the bottom surface of the lower waveguide layer 140, and the current limiting layer 110 is respectively connected to the top surface of the upper waveguide layer 120 and the ridge waveguide 300.

[0035] In this embodiment, the upper waveguide layer 120 and the lower waveguide layer 140 are respectively located on both sides of the quantum well active layer 130, and the upper waveguide layer 120 and the lower waveguide layer 140 are InAlGaAsGRIN-SCH (Gradient Refractive Index SeparateConfinement Heterostructure). There is a large bandgap width difference between the upper waveguide layer 120 and the lower waveguide layer 140 and the quantum well active layer 130, which confines the carriers in the quantum well active layer 130. In addition, there is a small refractive index difference between the upper waveguide layer 120 and the lower waveguide layer 140 and the quantum well active layer 130, and the refractive index gradually decreases from the quantum well active layer 130 to the outside, so that the photons are confined in the quantum well active layer 130, the upper waveguide layer 120 and the lower waveguide layer 140, and the light field confinement factor is increased. The gradient composition can also effectively improve the lattice matching and the quality of crystal epitaxy, and reduce the number of internal defects and non-radiative recombination centers.

[0036] The grating layer 150 is located below the lower waveguide layer 140. The grating layer 150 includes InGaAsP and InP. AlGaInAs is arranged at intervals in the InP. A periodically arranged structure is formed in the grating layer 150, so that light of a specific wavelength can be effectively reflected back into the cavity, thereby realizing laser oscillation. The grating layer 150 constitutes a resonant cavity, in which light waves propagate back and forth repeatedly and enhance their intensity. Voltage is applied to the chip and current is injected, so that the electrons in the quantum well active layer 130 continuously generate stimulated radiation. Under the action of negative feedback from the grating layer 150, the active module 100 works in a single longitudinal mode. The grating layer 150 plays a mode selection role, screening out lasers of a specific mode.

[0037] The current limiting layer 110 is located between the upper waveguide layer 120 and the ridge waveguide 300. The current limiting layer 110 may be an InAlAs Subcladding. The current limiting layer 110 can limit the diffusion of carriers from the active module 100 in the N region to the ridge waveguide 300 in the P region, so that the carriers are concentrated in the quantum well active layer 130, thereby reducing Ith (Lasing Threshold) and improving the photoelectric conversion efficiency.

[0038] In some embodiments provided in this application, Figure 3 As shown, optionally, the semiconductor laser device 10 further includes: an etch stop layer 410 and a second filling layer 420, the etch stop layer 410 is connected to the top surface of the active module 100 and the passive waveguide 200, and the second filling layer 420 is connected to the top surface of the etch stop layer 410. The ridge waveguide 300 includes: a first filling layer 330, the first filling layer 330 is connected to the top surface of the etch stop layer 410, the material of the second filling layer 420 is the same as that of the first filling layer 330, and is located on both sides of the first filling layer 330, and the second filling layers 420 on both sides respectively form processing grooves 450 with the first filling layer 330, and the first filling layer 330 constitutes the first conductive part 310 and the second conductive part 320.

[0039] In this embodiment, the etching stop layer 410 may be InGaAsP, and the second filling layer 420 and the first filling layer 330 are both InP cladding. When manufacturing the ridge waveguide 300, the etching stop layer 410 and the filling layer are epitaxially grown on the top surfaces of the passive waveguide 200 and the active module 100 in sequence, and part of the filling layer is removed by photolithography, etching and corrosion on the surface of the wafer, and two processing grooves 450 are processed to divide the filling layer into the first filling layer 330 and the second filling layer 420. The first filling layer 330 is located between the two second filling layers 420, and the processing grooves 450 are formed between the second filling layers 420 on both sides and the first filling layer 330. Among them, the etching generally adopts wet etching. In order to control the morphology after etching, the etching stop layer 410 is set to block the etching solution and prevent the solution from continuing to corrode the active module 100 downward.

[0040] The first conducting portion 310 and the second conducting portion 320 are constructed by a first filling layer 330 , and the first filling layer 330 constructs a horn shape of a waveguide structure.

[0041] Exemplarily, the depth of the processed groove 450 is 1.5 um to 2 um.

[0042] In some embodiments provided in this application, Figure 3As shown, optionally, the ridge waveguide 300 further includes: a first contact layer 340, the first contact layer 340 is connected to the top surface of the first filling layer 330, and the two ends of the first contact layer 340 along the laser emission direction are respectively contracted inward to form an insulating space 440, and the insulating spaces 440 on both sides are respectively opposite to the passive waveguide 200. The semiconductor laser device 10 further includes: a second contact layer 430, an insulating layer 500 and a metal layer 900, the second contact layer 430 is connected to the top surface of the second filling layer 420, the material of the second contact layer 430 is the same as that of the first contact layer 340, the insulating layer 500 is connected to the outer end surface of the ridge waveguide 300, a contact window is provided on the insulating layer 500, and the contact window avoids the first contact layer 340, the metal layer 900 covers the ridge waveguide 300 and the insulating layer 500, and the metal layer 900 forms an ohmic contact with the first contact layer 340.

[0043] In this embodiment, the first contact layer 340 and the second contact layer 430 may be InGaAs. When the contact layer is epitaxially grown on the filling layer and a part of the filling layer is removed by photolithography, etching and corrosion on the wafer surface, a part of the contact layer is removed together, and two processing grooves 450 are processed to divide the contact layer into the first contact layer 340 prototype and the second contact layer 430. The first contact layer 340 prototype is located between the two second contact layers 430. The first contact layer 340 prototype is partially removed at both ends by photolithography and corrosion, that is, the first contact layer 340 prototype above the passive waveguide 200 is removed, and the insulating space 440 is processed to avoid carrier injection in the insulating space 440, thereby processing and forming the first contact layer 340.

[0044] An insulating layer 500 is grown on the ridge waveguide 300, and the insulating layer 500 may be SiO2. The insulating layer 500 covers the periphery of the ridge waveguide 300 and the inner wall of the processing groove 450, and fills the insulating space 440. The insulating layer 500 above the first contact layer 340 is removed by photolithography and corrosion, and a contact window is processed. On the top of the insulating layer 500, a specific pattern is photolithographed, and a covering metal layer 900 is deposited, and the metal layer 900 covers the ridge waveguide 300 and the insulating layer 500. The first contact layer 340 avoided by the contact window can form an ohmic contact with the metal layer 900, providing an injection channel for current.

[0045] In some embodiments provided in this application, Figure 1 As shown, optionally, the semiconductor laser device 10 further includes: a buffer layer 600 and a substrate layer 700, the buffer layer 600 is connected to the bottom surface of the active module 100, the substrate layer 700 is connected to the bottom surface of the buffer layer 600, the buffer layer 600 and the substrate layer 700 are made of the same material, the etch stop layer 410 and the buffer layer 600 extend out of the active module 100 in the circumferential direction, and form a receiving space 800, and the passive waveguide 200 is located in the receiving space 800.

[0046] In this embodiment, the substrate layer 700 is located below the buffer layer 600. The substrate layer 700 may be InP, which plays a role of mechanical support and conductivity, and lays a technological foundation for subsequent epitaxial growth, corrosion, and metallization processes.

[0047] The buffer layer 600 is located below the active module 100 . The buffer layer 600 may be InP. The buffer layer 600 can play the role of lattice matching, thermal expansion coefficient matching and defect blocking.

[0048] The etch stop layer 410 and the buffer layer 600 extend out of the active module 100 in the circumferential direction. When processing the passive waveguide 200, part of the outer end of the active module 100 is removed in the circumferential direction so that the active module 100 shrinks inward relative to the buffer layer 600. A corrosion area is processed in the circumferential direction of the active module 100. The corrosion area forms a containing space 800. The passive waveguide 200 is grown in the corrosion area so that the passive waveguide 200 surrounds the outer periphery of the active module 100.

[0049] In a second aspect of the present application, an embodiment provides a method for manufacturing a semiconductor laser device, such as Figure 4 As shown, the method for manufacturing the semiconductor laser device is used to manufacture the semiconductor laser device provided by any one of the first aspect embodiments described above, and the method for manufacturing the semiconductor laser device comprises:

[0050] Step 101, epitaxially growing a buffer layer on the top surface of the substrate layer;

[0051] Step 102, growing an active module on the top surface of the buffer layer;

[0052] Step 103, removing part of the outer end of the active module along the circumferential direction to form an accommodation space;

[0053] Step 104, growing a passive waveguide in the accommodation space;

[0054] Step 105 , fabricating ridge waveguides on the top surfaces of the passive waveguides and active modules.

[0055] In this embodiment, a buffer layer and an active module are epitaxially grown in sequence by using metal-organic chemical vapor deposition (MOCVD) technology on a substrate layer. By step-by-step photolithography and wet etching, a portion of the outer end of the active module is removed in the circumferential direction, so that the active module shrinks inward relative to the buffer layer, and an etched area is processed in the circumferential direction of the active module, and the etched area forms a receiving space. By using SiO2 as a mask, a passive waveguide is grown in the etched area so that the passive waveguide surrounds the outer periphery of the active module.

[0056] A flared ridge waveguide is fabricated on the top surface of the passive waveguide and the active module.

[0057] By setting up mutually coordinated trumpet-shaped ridge waveguides and passive waveguides, after the reflected light is reflected to the end face of the semiconductor laser device, it needs to pass through a section composed of the passive waveguide and the trumpet-shaped ridge waveguide before entering the quantum well active layer. In this section, the reflected light is significantly reduced in mode coupling efficiency of the light wave due to the shrinkage of the width of the ridge waveguide from wide to narrow, and the reverse transmittance is reduced, thereby reducing the reflected light entering the quantum well active layer, improving the light field stability in the resonant cavity, and enhancing the anti-reflection ability of the semiconductor laser device, meeting the anti-reflection requirements of the semiconductor laser device, removing the isolator, and greatly reducing the production cost of the overall optical module.

[0058] In some embodiments provided in the present application, optionally, the step of growing an active module on the top surface of the buffer layer specifically includes: growing a grating layer on the top surface of the buffer layer; growing a lower waveguide layer on the top surface of the grating layer; growing a quantum well active layer on the top surface of the lower waveguide layer; growing an upper waveguide layer on the top surface of the quantum well active layer; and growing a current limiting layer on the top surface of the upper waveguide layer.

[0059] In this embodiment, a grating layer, a lower waveguide layer, a quantum well active layer, an upper waveguide layer and a current limiting layer are epitaxially grown in sequence on the top surface of the buffer layer.

[0060] The upper waveguide layer and the lower waveguide layer confine the carriers in the quantum well active layer, and confine the photons in the quantum well active layer, the upper waveguide layer and the lower waveguide layer, increasing the light field confinement factor, improving the lattice matching and the crystal epitaxy quality, and reducing the number of internal defects and non-radiative recombination centers. The grating layer plays a role in mode selection, making the active module work in a single longitudinal mode and screening out lasers of a specific mode. The current limiting layer can concentrate the carriers in the quantum well active layer, reduce Ith, and improve the photoelectric conversion efficiency.

[0061] In some embodiments provided in the present application, optionally, the step of manufacturing a ridge waveguide on the top surface of the passive waveguide and the active module specifically includes: growing an etch stop layer on the top surface of the passive waveguide and the active module; growing a filling layer on the top surface of the etch stop layer; growing a contact layer on the top surface of the filling layer; processing two processing grooves on the filling layer and the contact layer to form a first filling layer and a second filling layer, as well as a first contact layer prototype and a second contact layer; removing the first contact layer prototype above the passive waveguide, processing an insulating space, and forming a first contact layer.

[0062] In this embodiment, an etch stop layer, a filling layer and a contact layer are epitaxially grown on the top surfaces of the passive waveguide and the active module in sequence, and a portion of the filling layer and the contact layer are removed by photolithography, etching and corrosion on the wafer surface, and two processing grooves are processed to divide the filling layer into a first filling layer and a second filling layer, and the contact layer into a first contact layer prototype and a second contact layer. The first filling layer is located between the two second filling layers, and the first contact layer prototype is located between the two second contact layers. Between the two processing grooves, the horn shape of the ridge waveguide is formed by the remaining first filling layer and the first contact layer prototype.

[0063] Part of the first contact layer sample is removed at both ends by photolithography and etching, that is, the first contact layer sample above the passive waveguide is removed, and an insulating space is processed to avoid carrier injection in the insulating space, thereby forming the first contact layer.

[0064] Exemplarily, the length removed at the light emitting end may be 30 um to 50 um, and the length removed at the other end may be 5 um to 15 um.

[0065] In some embodiments provided in the present application, optionally, after the step of processing the insulating space, it also includes: growing an insulating layer on the outside of the ridge waveguide; removing the insulating layer above the first contact layer to process a contact window; depositing a covering metal layer on top of the first contact layer and the insulating layer; and cutting the metal layer.

[0066] In this embodiment, an insulating layer is grown on the top of the outer side of the ridge waveguide, the insulating layer covers the outer side of the ridge waveguide and the inner wall of the processed groove, and fills the insulating space. The insulating layer above the first contact layer is removed by photolithography and corrosion, and a contact window is processed. On the top of the insulating layer, a specific pattern is photolithographed, a covering metal layer is deposited, and the metal layer is cut to form a desired shape. The first contact layer avoided by the contact window can form an ohmic contact with the metal layer, providing an injection channel for current.

[0067] Exemplarily, the metal layer includes a connection metal and a pad, the connection metal is connected to the ridge waveguide, and the connection metal is used to conduct the circuit. The upper end surface of the pad is coplanar with the upper end surface of the connection metal, which is convenient for adsorption operation when taking the semiconductor laser device.

[0068] In some embodiments provided in the present application, optionally, before the step of removing the insulating layer above the first contact layer, the method further includes: removing the insulating layer of a preset width at both ends of the insulating layer in a direction perpendicular to the laser emission. And / or after the step of cutting the metal layer, the method further includes: grinding and polishing the substrate layer to process the thickness of the semiconductor laser device to a preset thickness; and depositing metal on the bottom surface of the substrate layer.

[0069] In this embodiment, the insulating layer of a preset width is removed by photolithography and etching on both sides of the left and right sides of the laser emission direction, respectively, to reserve a cutting position for facilitating the subsequent decomposition of the wafer into grains.

[0070] The substrate layer is ground and polished to reduce the thickness of the semiconductor laser device to a preset thickness, and a metal for conducting the circuit is deposited on the bottom surface of the substrate layer.

[0071] Exemplarily, the preset width may be 15um to 20um, and the preset thickness may be 90um to 110um.

[0072] In a specific embodiment, the structure of the semiconductor laser device and the manufacturing method thereof are as follows:

[0073] 1. On the InP substrate layer, a metal organic chemical vapor deposition system is used to sequentially epitaxially grow an InP buffer layer, an InGaAsP grating layer, an AlGaInAs lower waveguide layer, an AlGaInAs ALQ-quantum well active layer, an AlGaInAs upper waveguide layer, and an InAlAs current limiting layer.

[0074] 2. Use stepper photolithography and wet etching to remove part of the active module, use SiO2 as a mask, grow passive waveguides in the etched area, and then grow etch stop layers, fill layers, and contact layers.

[0075] 3. Two 1.8um deep processing grooves are formed on the chip surface through photolithography, etching and corrosion, leaving a ridge waveguide in the middle, and a trumpet-shaped waveguide is made at the light output end.

[0076] 4. Remove the contact layer above the passive waveguide by photolithography and etching to avoid carrier injection at this location.

[0077] 5. Grow a SiO2 insulating layer, then use photolithography and etching to remove the SiO2 in specific areas to facilitate the subsequent decomposition of the wafer into grains.

[0078] 6. Remove the SiO2 insulating layer directly above the ridge waveguide through photolithography and etching to expose the contact layer.

[0079] 7. Photolithography is performed to produce a specific pattern, and the covering metal is deposited. The metal in the excess position is removed, and the metal above the ridge waveguide forms an ohmic contact with the contact layer.

[0080] 8. Grind and polish to reduce the thickness of the chip to 90um to 110um.

[0081] 9. Metal deposition is performed on the back side.

[0082] By adopting this structure, the intensity of light reflected back to the quantum well active layer can be reduced, thereby improving the output optical signal quality of the semiconductor laser device under a certain reflected light intensity.

[0083] According to this structure, three devices were actually manufactured for anti-reflection testing. The margin (eye diagram margin) was compared with the conventional solution under -12dB reflected light. The results are shown in Table 1:

[0084] Table 1

[0085] Sample 1 Sample 2 Sample 3 Conventional solution -36.7％ -46.1％ -28.1％ This application plan 7％ 8.1％ 12％

[0086] The numbers in the table represent the quality of the output optical signal of the semiconductor laser device after adding -12dB reflected light. The larger the number, the better the output optical signal of the semiconductor laser device and the stronger the anti-reflection ability. The epitaxial structures of the two schemes are the same, only the ridge waveguide shape is different. The ridge width of the ridge waveguide of the conventional scheme remains unchanged at 2um.

[0087] In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance; the term "plurality" refers to two or more, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0088] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “front” and “back” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention.

[0089] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0090] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A semiconductor laser device, characterized in that: include: An active module, the active module comprising a quantum well active layer, the quantum well active layer being used for emitting laser light; A passive waveguide circumferentially surrounds the outer side of the active module; A ridge waveguide is connected to the top surfaces of the active module and the passive waveguide, the ridge waveguide extends along the emission direction of the laser, the ridge waveguide includes a first transmission part and a second transmission part connected to each other, the ridge width of the second transmission part at one end close to the first transmission part gradually increases along the emission direction of the laser and is greater than the ridge width of the first transmission part, the second transmission part is located at the light emitting side of the active module, and the second transmission part is opposite to the passive waveguide.

2. The semiconductor laser device according to claim 1, wherein The active module also includes: an upper waveguide layer connected to the top surface of the quantum well active layer; A lower waveguide layer connected to the bottom surface of the quantum well active layer; a grating layer connected to the bottom surface of the lower waveguide layer; The current limiting layer is respectively connected to the top surface of the upper waveguide layer and the ridge waveguide.

3. The semiconductor laser device according to claim 1, wherein Also includes: an etch stop layer connected to the top surfaces of the active module and the passive waveguide; a second filling layer connected to the top surface of the etch stop layer; The ridge waveguide comprises: The first filling layer is connected to the top surface of the etch stop layer. The material of the second filling layer is the same as that of the first filling layer and is located on both sides of the first filling layer. Processing grooves are formed between the second filling layers on both sides and the first filling layer respectively. The first filling layer constitutes the first conduction part and the second conduction part.

4. The semiconductor laser device according to claim 3, wherein: The ridge waveguide further comprises: A first contact layer connected to the top surface of the first filling layer, wherein two ends of the first contact layer along the laser emission direction are respectively contracted inward to form an insulating space, and the insulating spaces on both sides are respectively opposite to the passive waveguide; The semiconductor laser device further comprises: a second contact layer connected to the top surface of the second filling layer, wherein the material of the second contact layer is the same as that of the first contact layer; an insulating layer connected to the outer end surface of the ridge waveguide, wherein a contact window is provided on the insulating layer, and the contact window avoids the first contact layer; A metal layer covers the ridge waveguide and the insulating layer, and the metal layer forms an ohmic contact with the first contact layer.

5. The semiconductor laser device according to claim 3, wherein: Also includes: A buffer layer connected to the bottom surface of the active module; The substrate layer is connected to the bottom surface of the buffer layer. The buffer layer and the substrate layer are made of the same material. The etching stop layer and the buffer layer extend out of the active module along the circumferential direction and form a receiving space. The passive waveguide is located in the receiving space.

6. A method for manufacturing a semiconductor laser device, for manufacturing the semiconductor laser device according to any one of claims 1 to 5, characterized in that: include: epitaxially growing a buffer layer on a top surface of the substrate layer; growing an active module on a top surface of the buffer layer; Removing a portion of the outer end of the active module along the circumferential direction to form an accommodation space; growing a passive waveguide in the accommodation space; Ridge waveguides are fabricated on the top surfaces of the passive waveguide and the active module.

7. The method for manufacturing a semiconductor laser device according to claim 6, wherein: The step of growing an active module on the top surface of the buffer layer specifically includes: growing a grating layer on the top surface of the buffer layer; growing a lower waveguide layer on the top surface of the grating layer; growing a quantum well active layer on the top surface of the lower waveguide layer; growing an upper waveguide layer on the top surface of the quantum well active layer; A current limiting layer is grown on the top surface of the upper waveguide layer.

8. The method for manufacturing a semiconductor laser device according to claim 6, wherein: The step of manufacturing a ridge waveguide on the top surface of the passive waveguide and the active module specifically includes: growing an etch stop layer on the top surface of the passive waveguide and the active module; growing a filling layer on the top surface of the etch stop layer; growing a contact layer on the top surface of the filling layer; Processing two processing grooves on the filling layer and the contact layer to form a first filling layer and a second filling layer, and a first contact layer prototype and a second contact layer; The first contact layer sample above the passive waveguide is removed, an insulating space is processed, and a first contact layer is formed.

9. The method for manufacturing a semiconductor laser device according to claim 8, wherein: After the step of processing the insulating space, the method further comprises: growing an insulating layer on the outer side of the ridge waveguide; removing the insulating layer above the first contact layer to form a contact window; depositing a capping metal layer on top of the first contact layer and the insulating layer; The metal layer is cut.

10. The method for manufacturing a semiconductor laser device according to claim 9, wherein: Before the step of removing the insulating layer above the first contact layer, the method further includes: Removing the insulating layer of a preset width at both ends of the insulating layer along a direction perpendicular to the laser emission; and / or After the step of cutting the metal layer, the method further comprises: Grinding and polishing the substrate layer to process the thickness of the semiconductor laser device to a preset thickness; Metal is deposited on the bottom surface of the substrate layer.

Images