Multi-beam semiconductor laser element, semiconductor laser device, and method for manufacturing the same

Abstract

To provide a semiconductor laser element in which a decrease in reliability during a coating process is suppressed.SOLUTION: A semiconductor laser element 100 includes three or more laser resonators 200_1 to 200_4 integrated adjacent to each other in the first direction. Each of the laser resonators 200 includes an independent power supply electrode 150, is elongated in the second direction, and has a coated end face. A plurality of electrode pads Pe1 to Pe4 are formed in pad regions 104 and 106 adjacent to a laser region 102 in the first direction. The connection wirings Lc1 to Lc4 each extend in the first direction and electrically connect the power supply electrode 150 of the corresponding laser resonator 200 to the corresponding electrode pad Pe. A thick film pad 170 is formed in the pad regions 104 and 106, and is higher than a stacked wiring structure 160 of the connection wirings Lc1 to Lc4.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a multi-beam semiconductor laser device. [Background technology]

[0002] Semiconductor lasers are used as light sources in electronic devices such as printers and head mounted displays (HMDs). To keep up with the increasing resolution of such electronic devices that handle images, multi-beam semiconductor laser elements are being adopted.

[0003] In order to miniaturize lenses and MEMS mirrors, it is necessary to narrow the beam pitch. If the beam pitch becomes narrower than the ball diameter of wire bonding or the solder pattern width of die bonding, it becomes impossible to secure an area for direct wire bonding or die bonding to the electrode on the upper surface of the laser resonator, and as a result, it becomes necessary to form the electrode pad close to the edge of the chip (semiconductor substrate). In this case, the connection wiring (laminated wiring) that connects the electrode pad and the laser resonator will straddle the laser resonator (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-135731 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have studied narrow-beam-pitch multi-beam semiconductor laser devices and have come to recognize the following problems.

[0006] The end faces of the multiple laser resonators of the multi-beam semiconductor laser element are coated with AR (Anti Reflection) coating or HR (High Reflection) coating. FIG. 1 is a diagram explaining the coating process. Prior to the coating process, semiconductor chips 4 (dies) are cut out from a wafer as a die array (LD bar) 6 in which multiple chips are integrated. The LD bar 6 is sandwiched and supported and fixed by a spacer 2, which is a jig. In this state, a coating is applied to the cleavage surface 8 of the LD bar 6. After coating, multiple semiconductor chips 4 are cut out from the LD bar 6 by a pelletizing process.

[0007] In a multi-beam semiconductor laser element with a narrow beam pitch, a pad electrode is arranged at the chip end. The wiring (called the connection wiring) that connects the power supply electrode (P-side electrode) formed on the upper surface of the central laser resonator and the pad electrode crosses the adjacent laser resonator. Focusing on the intersection of the connection wiring and the laser resonator, an insulating layer is inserted between the connection wiring and the power supply electrode of the laser electrode, forming a laminated wiring structure. This laminated wiring structure has a higher height (distance from the chip surface) than other parts. Therefore, when the LD bar 6 is fixed by the spacer 2 in the coating process, the laminated wiring structure comes into contact with the spacer 2, and pressure is concentrated. This may reduce the reliability of the semiconductor laser element. For example, if a crack occurs in the insulating layer of the laminated wiring structure, an electrical short circuit occurs between adjacent emitters.

[0008] It should be noted that this problem should not be understood as a common understanding among those skilled in the art, and moreover, this problem has been independently recognized by the present inventors.

[0009] An aspect of the present disclosure has been made in view of the above problems, and one exemplary purpose thereof is to provide a semiconductor laser element in which a decrease in reliability during a coating process is suppressed. [Means for solving the problem]

[0010] An embodiment of the present disclosure relates to a multi-beam semiconductor laser element. The multi-beam semiconductor laser element includes three or more laser resonators integrated adjacent to each other in a first direction in a laser region of a single semiconductor substrate. Each laser resonator has an independent power supply electrode, is elongated in a second direction, and has a coated end face. A pad region adjacent to the laser region in the first direction has a plurality of electrode pads corresponding to the plurality of laser resonators formed therein. The power supply electrodes of the corresponding laser resonators are electrically connected to the corresponding electrode pads by a plurality of connection wirings. The connection wirings have a stacked wiring structure at positions intersecting with the laser resonators. The multi-beam semiconductor laser element further includes a thick-film pad formed in the pad region and having a height higher than the stacked wiring structure of the connection wirings.

[0011] In addition, any combination of the above components, and mutual substitution of the components and expressions of the present disclosure between methods, devices, systems, etc. are also valid aspects of the present disclosure. Effect of the Invention

[0012] According to an aspect of the present disclosure, in a coating process for a multi-beam semiconductor laser, it is possible to prevent pressure from concentrating on a stacked wiring structure of connection wiring, thereby improving reliability. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram illustrating a coating process. [Diagram 2] 1 is a perspective view of a semiconductor laser device according to a first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view of the semiconductor laser device of FIG. [Figure 4] 3A to 3C are diagrams illustrating a coating process for the semiconductor laser element of FIG. 2. [Diagram 5] 1 is a cross-sectional view of a laser device including a semiconductor laser element. [Figure 6] 1 is a cross-sectional view of a laser device including a semiconductor laser element. [Figure 7]1 is a cross-sectional view of a laser device including a semiconductor laser element. [Figure 8] FIG. 11 is a perspective view of a semiconductor laser device according to a second embodiment. [Figure 9] FIG. 11 is a perspective view of a semiconductor laser device according to a third embodiment. [Figure 10] FIG. 11 is a perspective view of a semiconductor laser device according to a fourth embodiment. [Figure 11] FIG. 11 is a perspective view of a semiconductor laser device according to a fifth embodiment. [Figure 12] FIG. 13 is a perspective view of a semiconductor laser device according to a sixth embodiment. [Figure 13] FIG. 13 is a perspective view of a semiconductor laser device according to a seventh embodiment. [Figure 14] FIG. 13 is a perspective view of a semiconductor laser element according to a modified example. [Figure 15] FIG. 13 is a perspective view of a semiconductor laser device according to an eighth embodiment. [Figure 16] FIG. 13 is a plan view of a semiconductor laser device according to a ninth embodiment. [Figure 17] FIG. 13 is a plan view of a semiconductor laser device according to a tenth embodiment. [Figure 18] FIG. 15 is a plan view of a semiconductor laser device according to an eleventh embodiment. [Figure 19] FIG. 23 is a plan view of a semiconductor laser device according to a twelfth embodiment. [Figure 20] FIG. 23 is a perspective view of a semiconductor laser device according to a thirteenth embodiment. [Figure 21] FIG. 21 is a plan view showing one embodiment of the semiconductor laser device of FIG. 20. [Figure 22] FIG. 22 is a cross-sectional view of the semiconductor laser device of FIG. 21. [Figure 23] FIG. 21 is a perspective view of a semiconductor laser device according to a fourteenth embodiment. [Figure 24] 1A to 1C are diagrams illustrating a manufacturing method of a semiconductor laser element. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] (Overview of the embodiment) A summary of some exemplary embodiments of the present disclosure is provided. This summary is intended as a prelude to the more detailed description that follows, or as a basic understanding of the embodiments. This summary is intended to provide a simplified description of some concepts of one or more embodiments, and is not intended to limit the scope of the invention or disclosure. Additionally, this summary is not intended to be a comprehensive overview of all possible embodiments, nor is it intended to limit essential elements of the embodiments. For convenience, the term "one embodiment" may refer to one embodiment (example or variant) or multiple embodiments (examples or variants) disclosed in this specification.

[0015] A multi-beam semiconductor laser element according to one embodiment includes a plurality of laser resonators, three or more, integrated adjacent to each other in a first direction in a laser region of a single semiconductor substrate, each of the laser resonators having an independent power supply electrode, a longitudinal direction in a second direction, and a coated end face; a plurality of electrode pads corresponding to the plurality of laser resonators, formed in a pad region adjacent to the laser region in the first direction; a plurality of connection wires corresponding to the plurality of laser resonators, each extending in the first direction and electrically connecting the power supply electrode of a corresponding laser resonator to a corresponding electrode pad, the connection wires having a stacked wiring structure at positions intersecting with the laser resonators; and a thick film pad formed in the pad region and having a height higher than the stacked wiring structure of the connection wires.

[0016] With this configuration, when the LD bar consisting of multiple semiconductor laser elements is sandwiched and fixed by the spacer in the coating process, pressure is concentrated on the thick film pad, which reduces the force applied to the stacked wiring structure and improves the reliability of the semiconductor laser elements.

[0017] In one embodiment, the thick film pads may be formed of the same material as the electrode pads.

[0018] In one embodiment, the height of the electrode pad is higher than the height of the stacked wiring structure of the connection wiring, and the electrode pad may be a thick film pad. In this case, in the coating process, the surface of the thick film pad (electrode pad) comes into contact with the spacer, so that the coating material does not adhere to the surface of the electrode pad. Therefore, in the subsequent assembly process, the adhesion of the bonding wire or soldering can be improved.

[0019] In one embodiment, the thick film pad may be provided separately from the multiple electrode pads.

[0020] In one embodiment, the power supply electrode is a stripe-shaped electrode, an interlayer insulating film is formed on the stripe-shaped electrode, and the connection wiring may be formed on the interlayer insulating film.

[0021] In one embodiment, the interlayer insulating film may be polyimide, which can fill in the unevenness of the base and easily flatten the surface, making it possible to flatten the connection wiring and improving the coverage of the film.

[0022] In one embodiment, the thick film pad may be formed of the same material as the interlayer dielectric.

[0023] In one embodiment, the multi-beam semiconductor laser element may further include a prevention wall that crosses the multiple laser resonators, is formed over at least the entire laser region, and has substantially the same height as the thick-film pad. With this structure, when one end face of the laser resonator is being coated, the coating material can be prevented from adhering to the opposite end face, and the performance degradation of the coating film can be suppressed.

[0024] In one embodiment, the power supply electrode may be a stripe-shaped electrode. An interlayer insulating film may be formed on the stripe-shaped electrode, and the prevention wall may be formed of the same material as the interlayer insulating film.

[0025] In one embodiment, a plurality of thick film pads are formed, and the heights of the plurality of thick film pads may be substantially equal. This allows the spacer to be supported parallel to the semiconductor substrate in the coating process, and allows a large number of LD bars and spacers to be stably stacked. "Substantially equal" means that the heights are equal to the extent that this effect can be obtained.

[0026] In one embodiment, the spacing between the multiple laser cavities may be 100 μm or less.

[0027] A semiconductor laser device according to an embodiment includes any one of the multi-beam semiconductor laser elements described above, and a support substrate, in which the multi-beam semiconductor laser element is junction-up mounted on the support substrate.

[0028] A semiconductor laser device according to an embodiment includes the multi-beam semiconductor laser element according to any one of the above-described embodiments, and a support substrate. The multi-beam semiconductor laser element is junction-down mounted on the support substrate, and the electrode pads are connected to the pads on the support substrate by soldering.

[0029] In one embodiment, the support substrate may include a plurality of substrate-side electrode pads corresponding to the plurality of laser resonators. Each substrate-side electrode pad may be formed to overlap a connection wiring and an electrode pad of a corresponding laser resonator. The connection wiring and the electrode pad of each laser resonator may be soldered to the corresponding substrate-side electrode pad. This configuration can improve heat dissipation.

[0030] The method for manufacturing a multi-beam semiconductor laser element according to an embodiment may include a plating step of forming the connection wiring and the thick film pad by plating. Power supply in the plating step may be performed through the stripe-shaped electrodes and the intersections of the stripe electrodes and the connection wiring, or through the openings if the openings are provided in the interlayer insulating film.

[0031] (Embodiment) Hereinafter, the present disclosure will be described with reference to the drawings based on preferred embodiments. The same or equivalent components, parts, and processes shown in each drawing will be given the same reference numerals, and duplicated descriptions will be omitted as appropriate. In addition, the embodiments are not intended to limit the disclosure, but are merely examples, and all features and combinations thereof described in the embodiments are not necessarily essential to the disclosure.

[0032] The dimensions (thickness, length, width, etc.) of each component shown in the drawings may be enlarged or reduced as appropriate for ease of understanding. Furthermore, the dimensions of multiple components do not necessarily represent their relative sizes. Even if a component A is drawn thicker than another component B on the drawings, component A may actually be thinner than component B.

[0033] (Embodiment 1) 2 is a perspective view of the semiconductor laser device 100 according to embodiment 1. The semiconductor laser device 100 is an edge-emitting semiconductor laser device, and is a multi-beam semiconductor laser having a plurality of m emitters (m≧3). In this embodiment, the number of emitters is 4.

[0034] The semiconductor laser element 100 includes an N-type semiconductor substrate 110 and a laminated growth layer 120 formed on the N-type semiconductor substrate 110. The laminated growth layer 120 includes an N-type cladding layer 122, an emission layer 130, a P-type cladding layer 124, and a P-type contact layer (not shown), which are laminated in this order on the N-type semiconductor substrate 110. The emission layer 130 includes an N-type guide layer (lower guide layer), an active layer made of a quantum well layer, and a P-type guide layer (upper guide layer). The materials of the N-type semiconductor substrate 110 and the laminated growth layer 120 may be selected according to the required oscillation wavelength, and are not particularly limited in the present disclosure.

[0035] The semiconductor laser element 100 has a central laser region 102 and pad regions 104 and 106. In the laser region 102, m (m≧3) laser cavities 200 adjacent to each other in a first direction (x direction) are formed. Each laser cavity 200 has a stripe structure extending in a second direction (y direction) perpendicular to the first direction (x direction).

[0036] In the laminated growth layer 120, a waveguide structure for confining light is formed, and the cleavage planes at both ends of this waveguide structure serve as mirrors to form a Fabry-Perot type laser resonator 200. In this example, four laser resonators 200_1 to 200_4 are formed, and a beam is emitted in the y direction from the emission end facet. The end facet of each laser resonator is coated to provide a desired reflectance.

[0037] The waveguide structure may be, for example, a buried ridge waveguide.

[0038] Alternatively, the waveguide structure may be a CSP (Channeled Substrate Planar) structure in which a groove is formed in the N-type semiconductor substrate 110 along the waveguide, and the thickness of the N-type cladding layer 122 in the groove is relatively thick.

[0039] Although the buried ridge structure and the CPS structure are waveguide structures that utilize a refractive index distribution, the present disclosure is not limited thereto, and a gain waveguide structure that utilizes a gain distribution may be used. These structures are light confinement structures, and can also be understood as current confinement structures.

[0040] A power supply electrode (P-side electrode) 150 is formed on the upper surface of the laser resonator 200. In order to enable the laser resonator 200 to be driven independently, the power supply electrodes 150 are electrically insulated from each other, and the P-type semiconductor portion has an electrical resistance between each emitter, so that the power supply electrodes 150 can be driven independently. In this embodiment, the power supply electrode 150 is a stripe-shaped electrode extending along the y direction on the upper surface of the laser resonator 200.

[0041] In order to feed power to the laser resonator 200, a plurality of chip-side electrode pads (hereinafter simply referred to as electrode pads) Pe1 to Pe4 and a plurality of connection wires Lc1 to Lc4 are provided corresponding to the plurality of laser resonators 200_1 to 200_4.

[0042] A plurality of electrode pads Pe1 to Pe4 are formed in pad regions 104 and 106 adjacent in the x-direction to the laser region 102. In the case of junction-up mounting, bonding wires are connected to the electrode pads Pe1 to Pe4, and in the case of junction-down mounting, solder is connected to the electrode pads Pe1 to Pe4.

[0043] Each of the connection wires Li (i=1, 2, 3, 4) electrically connects the power supply electrode 150 of the corresponding laser resonator 200_i to the corresponding electrode pad Pi.

[0044] For the two inner ones (200_2, 200_3) of the multiple laser resonators 200_1 to 200_4, the connection wirings Lc2 and Lc3 cross the outer laser resonators. Specifically, the connection wiring Lc2 crosses the laser resonator 200_1. The connection wiring Lc2 has a multilayer wiring structure 160 at a position where it intersects with the laser resonator 200_1. The multilayer wiring structure 160 includes an interlayer insulating film 162 formed between the connection wiring Lc2 and the power supply electrode 150.

[0045] Similarly, the connection wire Lc3 crosses the laser resonator 200_4. The connection wire Lc4 has a laminated wiring structure 160 at the position where it intersects with the laser resonator 200_4.

[0046] The interlayer insulating film 162 may be made of an inorganic material such as SiO2 or an organic material such as polyimide. SiO2 is advantageous in terms of heat dissipation because it is easy to make a thin film. Polyimide has the advantage that it can fill in the unevenness of the base and the surface is easily made flat, so that the connection wiring Lc can be flattened and the film coverage is improved, but it is difficult to form a thin film, which makes cleavage and pelletization difficult.

[0047] In this embodiment, the semiconductor laser element 100 includes a thick film pad 170. The thick film pad 170 is formed in the pad regions 104 and 106, and is higher than the stacked wiring structure 160 of the connection wirings Lc2 and Lc3. The height can be understood as the distance from a reference plane perpendicular to the z-axis, and for example, the front or back surface of the N-type semiconductor substrate 110 can be taken as the reference plane. The difference Δh between the height of the thick film pad 170 and the height of the stacked wiring structure 160 is preferably larger than 1 μm, and more preferably 5 μm or more.

[0048] In this embodiment, the thick film pad 170 also serves as the electrode pads Pe1 to Pe4, and is made of a metal material. In other words, in order for the electrode pads Pe1 to Pe4 to function as the thick film pads 170, they are formed thicker than normal electrode pads.

[0049] Fig. 3 is a cross-sectional view of the semiconductor laser element 100 of Fig. 2. This cross-sectional view shows a cross section of the semiconductor laser element 100 in the xz plane at the position where the connection wirings Lc2 and Lc3 are formed. A high electrical resistance region 204 is formed between adjacent laser resonators 200 by, for example, ion implantation. A contact insulating film 154 is formed on the multilayer growth layer 120, and the contact insulating film 154 has an opening on the lower surface of the power supply electrode. The contact insulating film 154 is formed of, for example, a material such as SiO2.

[0050] A P-type contact layer 126 is formed on the P-type cladding layer 124, and a power supply electrode 150 is formed on the P-type contact layer 126. An interlayer insulating film 162_1 is formed on the power supply electrode 150_1 of the laser resonator 200_1. A connection wiring Lc2 is formed across the interlayer insulating film 162_1. An interlayer insulating film 162_4 is formed on the power supply electrode 150_4 of the laser resonator 200_4. A connection wiring Lc3 is formed across the interlayer insulating film 162_4.

[0051] The above is the configuration of the semiconductor laser device 100. Next, the advantages thereof will be described.

[0052] Fig. 4 is a diagram for explaining a coating process for the semiconductor laser element 100 of Fig. 2. An LD bar 6 including a plurality of semiconductor laser elements 100 is cut out from a wafer. The LD bar 6 is sandwiched and supported and fixed by spacers 2. In this state, a coating process is applied to the end face of each semiconductor laser element 100.

[0053] The semiconductor laser element 100 comes into contact with the spacer 2 at the thick film pad 170 which is the highest, and the multilayer wiring structure 160 does not come into contact with the spacer 2. Therefore, the pressure applied to the multilayer wiring structure 160 can be reduced, and a decrease in the reliability of the semiconductor laser element 100 can be prevented.

[0054] Next, an example of mounting the semiconductor laser device 100 will be described.

[0055] 5 is a cross-sectional view of a semiconductor laser device 300 including a semiconductor laser element 100. The semiconductor laser device 300 includes a support substrate (also referred to as a submount) 310 and the semiconductor laser element 100. The semiconductor laser element 100 is mounted on the support substrate 310 in a junction-up manner, that is, with the N-side electrode 152 facing the support substrate 310.

[0056] The electrode pads Pe2 and Pe3 are connected to a lead (anode) of a package (not shown) or an anode of a driving circuit via bonding wires 320_2 and 320_3. The N-side electrode 152 is connected to an electrode 312 formed on a support substrate 310 via solder 322. The electrode 312 is connected to a lead (cathode) of a package (not shown) or a cathode of a driving circuit via a bonding wire 324.

[0057] 6 is a cross-sectional view of a laser device including a semiconductor laser element 100. The laser device 400 includes a support substrate 410 and the semiconductor laser element 100. The semiconductor laser element 100 is mounted on the support substrate 410 in a junction-down manner, that is, with the power supply electrode 150 facing the support substrate 410.

[0058] A plurality of substrate-side electrode pads 412_1 to 412_4 corresponding to a plurality of laser resonators 200_1 to 200_4 are formed on the support substrate 410. In the cross-sectional view of FIG. 6, only two substrate-side electrode pads 412_2 to 412_3 are shown. The electrode pads Pe2 and Pe3 are connected to substrate-side electrode pads (hereinafter simply referred to as electrode pads) 412_2 and 412_3 formed on the support substrate 410 via solders 420_2 and 420_3. The electrode pads 412_2 and 412_3 are connected to the lead (anode) of a package (not shown) or the anode of a driving circuit via bonding wires 422_2 and 422_3, respectively. The N-side electrode 152 is connected to the lead (cathode) of a package (not shown) or the cathode of a driving circuit via a bonding wire 424.

[0059] As shown in FIG. 6, the electrode pads Pe3 and Pe4, which are thick-film pads, play a role in preventing the stacked wiring structure 160 and the support substrate 410 from coming into contact with each other even when junction-down mounting is performed.

[0060] FIG. 7 is a cross-sectional view of a laser device including a semiconductor laser element 100. FIG. 7 is an example of junction-down mounting, similar to FIG. 6. In FIG. 7, the substrate-side electrode pad 412_2 corresponding to each laser resonator 200_2 is formed so as to overlap the electrode pad Pe2 and the connection wiring Lc2 of the corresponding laser resonator. The connection wiring Lc2 and the electrode pad Pe2 are connected to the substrate-side electrode pad 412_2 via the solder 420_2. The same applies to the connection wiring Lc3 side.

[0061] The configuration in FIG. 7 can improve heat dissipation compared to the configuration in FIG.

[0062] (Embodiment 2) 8 is a perspective view of a semiconductor laser device 100A according to the second embodiment. In the first embodiment, the electrode pads Pe1 to Pe4 also serve as the thick film pads 170. In contrast, in FIG. 8, the thick film pads 170A are formed independently of the electrode pads Pe1 to Pe4. In this configuration, the thick film pads 170A may be made of metal or an insulator. When the thick film pads 170A are made of an insulator, they can be formed by the same film formation process using the same material as the interlayer insulating film 162.

[0063] The function of the thick film pad 170A is to prevent the stacked wiring structure 160 from contacting the spacer in the coating process, and this function should be achieved in the state of the LD bar. As shown in Fig. 8, when the thick film pad 170A is formed only in the pad region 104 on one side, this function is achieved together with the thick film pad 170A similarly formed on another adjacent chip.

[0064] Of course, additional thick film pads 170A may be formed.

[0065] (Embodiment 3) 9 is a perspective view of a semiconductor laser device 100B according to embodiment 3. In the semiconductor laser device 100B, a pad region 104 is provided only on one side of the chip, and a laser region 102 is provided on the opposite side. All of the four electrode pads Pe1 to Pe4 are formed in the pad region 104.

[0066] The connection wiring Lc2 has a multilayer wiring structure 160 at an intersection with the power supply electrode 150_1. The connection wiring Lc3 has a multilayer wiring structure 160 at an intersection with the power supply electrodes 150_2 and 150_3. The connection wiring Lc4 has a multilayer wiring structure 160 at an intersection with the power supply electrodes 150_2, 150_3, and 150_4.

[0067] (Embodiment 4) The semiconductor laser element 100A in Fig. 8 and the semiconductor laser element 100B in Fig. 9 have a cantilever structure when mounted junction-down, and are therefore structurally unstable when the chip has a wide lateral width. In the fourth embodiment, a structure suitable for junction-down mounting will be described.

[0068] Fig. 10 is a perspective view of a semiconductor laser device 100C according to embodiment 4. The semiconductor laser device 100C is obtained by adding electrode pads Pe1' to Pe4', which are thick film pads 170, to the semiconductor laser device 100B in Fig. 9. The electrode pad Pei' (i = 1, 2, 3, 4) is adjacent to the electrode pad Pei in the x direction and is electrically connected to it.

[0069] According to this configuration, when junction-mounted, the semiconductor laser device 100 can be supported by the electrode pads Pe' in addition to the electrode pads Pe, thereby increasing the structural strength.

[0070] (Embodiment 5) Fig. 11 is a perspective view of a semiconductor laser device 100D according to the fifth embodiment. The width (width in the x direction) of the electrode pad Pe is wider than that of the electrode pad Pe in Fig. 9. This can also be understood as the electrode pads Pe and Pe' in Fig. 10 being formed continuously and integrally. With this configuration, when junction-mounted, the semiconductor laser device 100 can be supported by the wide electrode pad Pe, thereby increasing the structural strength.

[0071] (Embodiment 6) 12 is a perspective view of a semiconductor laser device 100E according to the sixth embodiment. The semiconductor laser device 100E is obtained by adding a plurality of thick film pads 170E to the semiconductor laser device 100B of FIG. 9. The plurality of thick film pads 170E are formed in the pad region 106. The thick film pads 170E are electrode pads, and are soldered to a support substrate when junction-down mounting is performed. However, since the thick film pads 170E do not contribute to driving the semiconductor laser device 100, they do not need to be electrically connected to the laser resonators 200_1 to 200_4.

[0072] According to this structure, when the semiconductor device is mounted with the junction down, a cantilever structure is not formed, and therefore the structural strength can be increased.

[0073] (Embodiment 7) FIG. 13 is a perspective view of a semiconductor laser device 100F according to the seventh embodiment. The semiconductor laser device 100F has six beams (six emitters) and includes six laser resonators 200_1 to 200_6 and six electrode pads Pe1 to Pe6. The electrode pads Pe1 to Pe6 are thick film pads 170 and are arranged in two rows. According to this configuration, similar to the semiconductor laser device 100c in FIG. 10, when the device is mounted in a junction-down manner, the cantilever is supported by two rows of electrode pads Pe, thereby increasing the structural strength. The configuration in FIG. 13 is effective when the resonator length, i.e., the length of the chip in the y direction, is short.

[0074] 14 is a perspective view of a semiconductor laser device 100a according to a modified example. Three or more electrode pads Pe may be provided for one connection wiring Lc. In this example, three electrode pads Pe6 are provided for a connection wiring Lc6. The multiple electrode pads Pe6 may be aligned in the x direction or in the y direction.

[0075] (Embodiment 8) 15 is a perspective view of a semiconductor laser device 100G according to the eighth embodiment. In the semiconductor laser device 100G, six electrode pads Pe1 to Pe6 are arranged in three rows. This configuration can further increase the strength when mounted in junction-down. This is also effective when the cavity length, i.e., the length of the chip in the y direction, is short.

[0076] In the first to seventh embodiments, the interlayer insulating film 162 is formed independently for each connection wiring Lc. However, as shown in FIG. 15, the interlayer insulating film 162 may be formed continuously.

[0077] Several examples of the range in which the interlayer insulating film 162 is formed will be described.

[0078] (Embodiment 9) 16 is a plan view of a semiconductor laser device 100H according to embodiment 9. The interlayer insulating film 162 is provided only where the connection wiring Lc intersects with the power supply electrode 150 and insulation is required. In this configuration, the interlayer insulating film 162 may be made of either SiO2 or polyimide.

[0079] (Embodiment 10) FIG. 17 is a plan view of the semiconductor laser device 100I according to the tenth embodiment. The interlayer insulating film 162 is formed widely over the range where the multiple connection wirings Lc are formed, and is formed in a region that does not overlap the electrode pads. However, the interlayer insulating film 162 is not formed near the cavity end face, and is configured to be easily cleaved and pelletized. In this configuration, the interlayer insulating film 162 covers almost the entire laser region 102, and can prevent electrical shorts between the power supply electrodes 150_i. It is also effective in preventing electrical shorts caused by the adhesion of conductive foreign matter in the manufacturing process and assembly process of a narrow-pitch multi-beam laser. In addition, the interlayer insulating film itself can dissipate heat, and the area of ​​the connection wiring provided thereon can be made large, thereby providing a heat dissipation effect to the connection wiring. The interlayer insulating film 162 has openings 164_i at the locations where the connection wirings Lc_i (i=1, 2, 3, 4) and the power supply electrodes 150_i should be connected. In this configuration, the interlayer insulating film 162 may be made of either SiO2 or polyimide.

[0080] (Embodiment 11) 18 is a plan view of the semiconductor laser device 100J according to the eleventh embodiment. The interlayer insulating film 162 is formed over a wide range including the electrode pads Pe1 to Pe4, and the connection wiring Lc and the electrode pads Pe are formed on the interlayer insulating film 162. However, it is not formed on the outer periphery of the N-type semiconductor substrate 110, and is configured to be easily cleaved and pelletized. In this configuration, since there is no boundary of the interlayer insulating film 162 between the laser region and the pad region, it is possible to prevent a decrease in coverage of the connection wiring Lc at the boundary step. In this configuration, the interlayer insulating film 162 may be formed of either SiO2 or polyimide.

[0081] (Embodiment 12) 19 is a plan view of a semiconductor laser device 100K according to embodiment 12. An interlayer insulating film 162 is formed over the entire N-type semiconductor substrate 110. In this configuration, if the interlayer insulating film 162 is made of polyimide, cleavage and pelletizing become difficult. Therefore, it is preferable to select a material for the interlayer insulating film 162 that can be thinned, such as SiO2.

[0082] (Embodiment 13) As described with reference to FIG. 4, the thick film pad 170 can prevent the stacked wiring structure 160 from colliding with the spacer 2, but on the other hand, the gap between the surface of the semiconductor laser element 100 and the surface of the spacer 2 becomes wider. Therefore, when coating one end face of the semiconductor laser element 100, the coating material may pass through this gap and get onto the opposite end face and adhere thereto. If the coating material unintentionally adheres to the opposite end face, it may cause manufacturing variations or may not be possible to obtain the reflection characteristics as designed. In the thirteenth embodiment, a technique for solving this problem will be described.

[0083] FIG. 20 is a perspective view of a semiconductor laser device 100L according to the thirteenth embodiment. The semiconductor laser device 100L includes a prevention wall 180 in addition to a thick film pad 170. The prevention wall 180 crosses the laser resonators 200_1 to 200_4 in the x direction and is formed over at least the entire laser region 102. The prevention wall 180 has substantially the same height as the thick film pad 170. The prevention wall 180 may be made of a metal or an insulator. When the prevention wall 180 is made of a metal, an insulating layer is inserted between the prevention wall 180 and the power supply electrode 150. The prevention wall 180 may be made of the same material as the thick film pad 170 or a different material.

[0084] According to the semiconductor laser device 100L, the prevention walls 180 and the spacers 6 come into contact with each other in the coating process, so that it is possible to prevent the coating material from flowing around.

[0085] Fig. 21 is a plan view showing one embodiment of the semiconductor laser device 100L of Fig. 20. The interlayer insulating film 162 is formed over a wide range except for the outer periphery of the N-type semiconductor substrate 110, similar to the semiconductor laser device 100J of Fig. 18.

[0086] In this embodiment, the prevention wall 180 is made of the same metal as the electrode pads Pe1 to Pe4. In the region where the prevention wall 180 is to be formed, a wiring layer 182 serving as a base is formed using the same material and process as the connection wiring Lc. The prevention wall 180 is formed on the wiring layer 182 using the same material and process as the electrode pads Pe.

[0087] Fig. 22 is a cross-sectional view of the semiconductor laser device 100L of Fig. 21. The upper part of Fig. 22 is a cross-sectional view taken along line AA in Fig. 21, and the lower part is a cross-sectional view taken along line BB in Fig. 21.

[0088] (Embodiment 14) 23 is a perspective view of a semiconductor laser device 100M according to embodiment 14. The prevention wall 180 is formed continuously and integrally with one or some of the electrode pads Pe1 to Pe4 (electrode pad Pe1 in this example).

[0089] (Manufacturing method) Next, a description will be given of a manufacturing method for the semiconductor laser device 100 in which the electrode pads Pe also serve as the thick film pads 170. This manufacturing method includes a plating step for forming the thick film pads 170 by plating.

[0090] 24 is a diagram illustrating a manufacturing method of the semiconductor laser element 100. The power supply electrode 150 of the semiconductor laser element 100 is continuous with the power supply electrode 150 of the adjacent semiconductor laser element 100, and is electrically connected to plated power supply pins 502, 504 provided on the outer periphery of the wafer 500.

[0091] In the plating process, photoresist is applied on the wafer 500. The photoresist is opened in the plating film formation region. For example, when a thick film pad is plated, the photoresist is opened in the formation portion of the thick film pad 170, that is, the electrode pads Pe1 to Pe4. The wafer 500 is immersed in a plating solution, and power is supplied to the plating power supply pins 502 and 504 from the outside. As a result, power is supplied to the electrode pad Pe via the power supply electrode 150 and the connection wiring Lc, and a plating film is formed on the electrode pad Pe, and the thick film pad 170 can be formed. In other words, it is possible to omit a process of providing a separate power supply electrode wiring for supplying power to the thick film pad, or removing an unnecessary power supply electrode wiring after plating, thereby reducing manufacturing costs. This manufacturing method can also be used in the case where plating is to be formed to increase the film thickness of the connection wiring portion. In this case, the photoresist is opened in the connection wiring portion, and power is supplied to the connection wiring portion, which has been thinly formed in advance by evaporation or the like, via the power supply electrode 150, and plating is formed on the connection wiring portion.

[0092] In the semiconductor laser device 100M of FIG. 23, power is supplied to the wiring layer 182 underlying the electrode pads Pe and the prevention walls 180 by this plating method, so that the prevention walls 180 can be formed simultaneously with the electrode pads Pe.

[0093] The embodiments merely illustrate the principles and applications of the present invention, and many modifications and changes in arrangement are permitted to the embodiments without departing from the spirit of the present invention defined in the claims. [Explanation of symbols]

[0094] 100 Semiconductor laser element 102 Laser Region 104,106 Pad Area 110 N-type semiconductor substrate 120 Layered Growth 122 N-type cladding layer 124 P-type cladding layer 130 Light-emitting layer PE electrode pad Lc connection wiring 150 Power supply electrode 152 N side electrode 154 Contact insulating film 160 Multilayer wiring structure 162 Interlayer insulating film 170 Thick Film Pad 180 Prevention wall 200 Laser resonator 300 Semiconductor laser device 310 Support Board

Claims

1. A multi-beam semiconductor laser element, a plurality of laser resonators, three or more, integrated adjacent to each other in a first direction in a laser region of a single semiconductor substrate, each of the laser resonators having an independent power supply electrode, a longitudinal direction in the second direction, and a coated end face; a plurality of electrode pads corresponding to the plurality of laser resonators, the electrode pads being formed in a pad region adjacent to the laser region in the first direction; a plurality of connection wires corresponding to the plurality of laser resonators, each extending in the first direction and electrically connecting the power supply electrode of the corresponding laser resonator to the corresponding electrode pad, the connection wires having a laminated wiring structure at positions intersecting the laser resonators; a thick film pad formed in the pad region and having a height higher than the stacked wiring structure of the connection wiring; A multi-beam semiconductor laser device comprising:

2. 2. The multi-beam semiconductor laser device according to claim 1, wherein the thick film pads are made of the same material as the electrode pads.

3. 2. The multi-beam semiconductor laser device according to claim 1, wherein the height of said electrode pad is greater than the height of said laminated wiring structure of said connection wiring, and said electrode pad is said thick film pad.

4. 2. The multi-beam semiconductor laser device according to claim 1, wherein the thick film pad is provided separately from the plurality of electrode pads.

5. 2. The multi-beam semiconductor laser element according to claim 1, wherein the power supply electrode is a stripe-shaped electrode, an interlayer insulating film is formed on the stripe-shaped electrode, and the connection wiring is formed on the interlayer insulating film.

6. 6. A multi-beam semiconductor laser device according to claim 5, wherein the interlayer insulating film is made of polyimide.

7. 7. The multi-beam semiconductor laser device according to claim 5, wherein the thick film pad is made of the same material as the interlayer insulating film.

8. 6. The multi-beam semiconductor laser device according to claim 1, further comprising a prevention wall formed on the plurality of laser resonators, extending in the first direction, and having substantially the same height as the thick film pads.

9. 9. The multi-beam semiconductor laser element according to claim 8, wherein the power supply electrode is a stripe-shaped electrode, an interlayer insulating film is formed on the stripe-shaped electrode, and the prevention wall is formed of the same material as the interlayer insulating film.

10. 6. The multi-beam semiconductor laser device according to claim 1, wherein the number of said thick film pads is multiple, and the heights of the multiple thick film pads are substantially equal.

11. 6. The multi-beam semiconductor laser device according to claim 1, wherein the interval between the plurality of laser resonators is 100 [mu]m or less.

12. A multi-beam semiconductor laser element according to any one of claims 1 to 5, A support substrate; Equipped with The semiconductor laser device is characterized in that the multi-beam semiconductor laser element is junction-up mounted on the support substrate.

13. A multi-beam semiconductor laser element according to any one of claims 1 to 5, A support substrate; Equipped with The multi-beam semiconductor laser element is mounted on the support substrate in a junction-down manner.

14. the support substrate includes a plurality of substrate-side electrode pads corresponding to the plurality of laser resonators, and each substrate-side electrode pad is formed so as to overlap the connection wiring and the electrode pad of the corresponding laser resonator; 14. The semiconductor laser device according to claim 13, wherein the connection wiring and the electrode pad of each laser resonator are joined to a corresponding substrate-side electrode pad by soldering.

15. 2. A method for manufacturing a multi-beam semiconductor laser device according to claim 1, comprising the steps of: the power supply electrode is a stripe electrode, forming the connection wiring and the thick film pad by plating; The manufacturing method according to claim 1, wherein power is supplied through the stripe electrodes in the plating step.

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