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

Abstract

The present invention addresses the problem of providing a semiconductor laser element in which a decrease in reliability during a coating step is suppressed. A semiconductor laser element (100) is provided with three or more laser resonators (200 - 1-200 - 4) integrated adjacent to each other in a first direction. Each of the laser resonators (200) has an independent power supply electrode (150), and has an end surface coated in the longitudinal direction in the second direction. The plurality of electrode pads (Pe1-Pe4) are formed in pad regions (104, 106) adjacent to the laser region (102) in the first direction. Connection wires (Lc1-Lc4) each extend in a first direction, and electrically connect a power supply electrode (150) of a corresponding laser resonator (200) and a corresponding electrode pad (Pe). The thick-film pads (170) are formed in the pad regions (104, 106), and are higher than the stacked wiring structure (160) of the connection wires (Lc1-Lc4).

Description

Technical Field

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

[0002] Semiconductor lasers are used as light sources in electronic devices such as printers and head mounted displays (HMDs). In order to cope with the higher resolution of such electronic devices that process images, multi-beam semiconductor laser elements are being adopted.

[0003] In order to miniaturize lenses and MEMS mirrors, it is required to narrow the beam pitch. If the beam pitch becomes narrower than the ball diameter of wire bonding or the width of the solder pattern of chip bonding, it is impossible to ensure the area for direct wire bonding or chip bonding on the electrode on the upper surface of the laser resonator. As a result, the electrode pad needs to be formed close to the end of the chip (semiconductor substrate). In this case, the connection wiring (laminated wiring) between the electrode pad and the laser resonator will cross the laser resonator (Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-135731 Summary of the invention

[0007] Problems that the invention will solve

[0008] The present inventors have studied a multi-beam semiconductor laser element with a narrow beam pitch and have come to realize the following problem.

[0009] The end faces of the plurality of laser resonators of the multi-beam semiconductor laser element are coated with AR (Anti Reflection) coating or HR (High Reflection) coating. Figure 1 1 is a diagram for explaining the coating process. Before the coating process, a bare chip array (LD strip) 6 in which a plurality of semiconductor chips 4 (bare chips) are integrated is cut out from a wafer. The LD strip 6 is clamped, supported, and fixed by a spacer 2 as a fixture. In this state, coating is applied to the cleavage surface 8 of the LD strip 6. After coating, a plurality of semiconductor chips 4 are cut out from the LD strip 6 through a granulation process.

[0010] In a multi-beam semiconductor laser element with a narrow beam pitch, a pad electrode is arranged at the end of the chip. The wiring (called connecting wiring) connecting the power supply electrode (P-side electrode) formed on the upper surface of the central laser resonator to the pad electrode crosses the adjacent laser resonator. If we focus on the intersection of the connecting wiring and the laser resonator, an insulating layer is inserted between the connecting wiring and the power supply electrode of the laser electrode, forming a stacked wiring structure. The stacked wiring structure is higher (the distance from the chip surface) than other parts. Therefore, in the coating process, when the LD strip 6 is fixed by the spacer 2, the stacked wiring structure contacts the spacer 2, and the pressure is concentrated. As a result, there is a risk of reduced reliability of the semiconductor laser element. For example, if a crack occurs in the insulating layer of the stacked wiring structure, an electrical short circuit occurs between adjacent emitters.

[0011] In addition, this problem cannot be understood as a general knowledge of those skilled in the art, and further, this problem is uniquely recognized by the present inventors.

[0012] One aspect of the present disclosure has been made in view of the above-mentioned problem, and one exemplary object of the present disclosure is to provide a semiconductor laser element in which a decrease in reliability in a coating process is suppressed.

[0013] Means for solving problems

[0014] A certain embodiment of the present disclosure relates to a multi-beam semiconductor laser element. The multi-beam semiconductor laser element has three or more laser resonators that are adjacent and integrated along a first direction in a laser region of a single semiconductor substrate. Each laser resonator has an independent power supply electrode, and the end face is coated with the second direction as the length direction. A plurality of electrode pads corresponding to the plurality of laser resonators are formed in a pad region adjacent to the laser region in the first direction. The power supply electrodes of the corresponding laser resonators are electrically connected to the corresponding electrode pads using a plurality of connection wirings. The connection wiring has a stacked wiring structure at a position intersecting with the laser resonator. The multi-beam semiconductor laser element also has a thick film pad formed in the pad region and having a height higher than the stacked wiring structure of the connection wiring.

[0015] Furthermore, arbitrarily combined forms of the above-described constituent elements, and forms in which constituent elements and expressions of the present disclosure are converted into methods, apparatuses, systems, and the like may also be additional modes of the present disclosure.

[0016] Effects of the Invention

[0017] According to one aspect of the present disclosure, in a multi-beam semiconductor laser coating process, it is possible to prevent stress from being concentrated on a stacked wiring structure of connection wiring, thereby improving reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a figure explaining the coating process.

[0019] Figure 2 This is a perspective view of the semiconductor laser element according to the first embodiment.

[0020] Figure 3 yes Figure 2 Cross-sectional view of a semiconductor laser element.

[0021] Figure 4 It is for Figure 2 Figure 2 is a diagram of the coating process of a semiconductor laser element.

[0022] Figure 5 This is a cross-sectional view of a laser device including a semiconductor laser element.

[0023] Figure 6 This is a cross-sectional view of a laser device including a semiconductor laser element.

[0024] Figure 7 This is a cross-sectional view of a laser device including a semiconductor laser element.

[0025] Figure 8 This is a perspective view of a semiconductor laser element according to the second embodiment.

[0026] Fig. 9 This is a perspective view of a semiconductor laser element according to a third embodiment.

[0027] Fig.10 This is a perspective view of a semiconductor laser element according to a fourth embodiment.

[0028] Fig.11 This is a perspective view of a semiconductor laser element according to a fifth embodiment.

[0029] Fig.12 This is a perspective view of a semiconductor laser element according to a sixth embodiment.

[0030] Fig.13 This is a perspective view of a semiconductor laser element according to a seventh embodiment.

[0031] Fig.14 It is a perspective view of a semiconductor laser element according to a modified example.

[0032] Fig.15 This is a perspective view of a semiconductor laser element according to an eighth embodiment.

[0033] Fig.16 This is a top view of a semiconductor laser element according to a ninth embodiment.

[0034] Fig.17 This is a top view of a semiconductor laser element according to a tenth embodiment.

[0035] Fig.18 This is a top view of a semiconductor laser element according to the eleventh embodiment.

[0036] Fig.19 This is a top view of a semiconductor laser element according to Embodiment 12.

[0037] Fig. 20 This is a perspective view of a semiconductor laser element according to embodiment 13.

[0038] Fig.21 Yes means Fig. 20 A top view of an embodiment of a semiconductor laser element.

[0039] Fig. 22 yes Fig.21 Cross-sectional view of a semiconductor laser element.

[0040] Fig.23 This is a perspective view of a semiconductor laser element according to a fourteenth embodiment.

[0041] Fig.24 It is a diagram for explaining a method for manufacturing a semiconductor laser element. DETAILED DESCRIPTION

[0042] (Overview of Embodiments)

[0043] An overview of several illustrative embodiments of the present disclosure is described. This overview serves as an introduction to the detailed description that will be described later, or is for the purpose of a basic understanding of the embodiments. This overview is a portion that briefly describes some concepts of one or more embodiments, and does not limit the scope of the invention or the disclosure. In addition, this overview is not a general overview of all conceivable embodiments, and does not limit the constituent elements that are indispensable to the embodiments. For convenience, "one embodiment" is sometimes used to refer to one embodiment (embodiment, variation) or multiple embodiments (embodiment, variation) disclosed in this specification.

[0044] A multi-beam semiconductor laser element in one embodiment comprises: three or more laser resonators (laser waveguides) integrated adjacent to each other along a first direction in a laser region of a single semiconductor substrate, each laser resonator having an independent power supply electrode and having an end face coated with a second direction as a length direction; a plurality of electrode pads formed in a pad region adjacent to the laser region in the first direction and corresponding to the plurality of laser resonators; a plurality of connection wirings corresponding to the plurality of laser resonators, extending in the first direction respectively and electrically connecting the power supply electrodes of the corresponding laser resonators to the corresponding electrode pads, the connection wirings having a stacked wiring structure at positions intersecting 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 wirings.

[0045] According to this configuration, in the coating process, when the LD bar composed of a plurality of semiconductor laser elements is sandwiched and fixed by the spacers, the pressure is concentrated on the thick film pad, thereby reducing the force applied to the stacked wiring structure and improving the reliability of the semiconductor laser element.

[0046] In one embodiment, the thick film pad may also be formed of the same material as the electrode pad.

[0047] In one embodiment, the height of the electrode pad may be 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) contacts the spacer, so the coated material does not adhere to the surface of the electrode pad. Therefore, in the subsequent assembly process, the adhesion of the bonding wire and solder can be improved.

[0048] In one embodiment, the thick film pad may also be provided separately from the plurality of electrode pads.

[0049] 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 connection wiring may be formed on the interlayer insulating film.

[0050] In one embodiment, the interlayer insulating film may be made of polyimide. Polyimide can fill the unevenness of the base and easily flatten the surface, thereby flattening the connection wiring and improving the coverage of the film.

[0051] In one embodiment, the thick film pad may be formed of the same material as the interlayer insulating film.

[0052] In one embodiment, the multi-beam semiconductor laser element may also include a prevention wall, which crosses the plurality of laser resonators and is formed at least throughout the entire laser region, and has substantially the same height as the thick film pad. According to this structure, when coating one end face of the laser resonator, it is possible to prevent the coated material from adhering to the end face on the opposite side, and it is possible to suppress the performance degradation of the coating film.

[0053] 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.

[0054] In one embodiment, a plurality of thick film pads may be formed, and the heights of the plurality of thick film pads may be substantially equal. Thus, in the coating process, the spacer can be supported parallel to the semiconductor substrate, and a plurality of LD strips and spacers can be stably stacked. Substantially equal means equal to the extent that this effect can be obtained.

[0055] In one embodiment, the interval between the plurality of laser resonators may be 100 μm or less.

[0056] A semiconductor laser device according to one embodiment includes any one of the multi-beam semiconductor laser elements described above and a supporting substrate. The multi-beam semiconductor laser element is mounted on the supporting substrate in a junction-up manner.

[0057] A semiconductor laser device according to one embodiment includes any of the above-described multi-beam semiconductor laser elements and a support substrate. The multi-beam semiconductor laser element is mounted on the support substrate in a junction-down manner, and a plurality of electrode pads are connected to a plurality of pads on the support substrate by solder.

[0058] In one embodiment, the support substrate may also include a plurality of substrate-side electrode pads corresponding to the plurality of laser resonators. Each substrate-side electrode pad may also be formed to overlap with the connection wiring and electrode pad of the corresponding laser resonator. The connection wiring and electrode pad of each laser resonator may also be joined to the corresponding substrate-side electrode pad using solder. According to this configuration, heat dissipation can be improved.

[0059] The manufacturing method of the multi-beam semiconductor laser element of one embodiment may also include an electroplating step of forming the connection wiring and the thick film pad by electroplating. The power supply in the electroplating step may also be performed via the stripe-shaped electrode and the intersection of the stripe electrode and the connection wiring, and in the case where the interlayer insulating film has an opening, it may also be performed via the opening.

[0060] (Implementation Method)

[0061] Hereinafter, the present disclosure will be described based on preferred embodiments with reference to the accompanying drawings. The same or equivalent components, parts, and processes shown in the various drawings are marked with the same reference numerals and repeated descriptions are appropriately omitted. In addition, the embodiments are examples and do not limit the disclosure. All features and combinations described in the embodiments are not necessarily the essence of the disclosure.

[0062] The dimensions (thickness, length, width, etc.) of each component recorded in the drawings may be appropriately enlarged or reduced for ease of understanding. Moreover, the dimensions of multiple components do not necessarily indicate their size relationship. Even if a certain component A is drawn thicker than another component B in the drawings, it is possible that component A is thinner than component B.

[0063] (Implementation Method 1)

[0064] Figure 2 1 is a perspective view of a semiconductor laser element 100 according to Embodiment 1. The semiconductor laser element 100 is an edge-emitting semiconductor laser element and is a multi-beam semiconductor laser having a plurality of m (m ≥ 3) emitters. In this embodiment, the number of emitters is four.

[0065] The semiconductor laser element 100 includes an N-type semiconductor substrate 110 and a stacked growth layer 120 formed on the N-type semiconductor substrate 110. The stacked growth layer 120 includes an N-type cladding layer 122, a light emitting layer 130, a P-type cladding layer 124, and a P-type contact layer (not shown), which are sequentially stacked on the N-type semiconductor substrate 110. The light emitting layer 130 includes an N-type guide layer (lower guide layer), an active layer composed 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 stacked growth layer 120 can be selected according to the desired oscillation wavelength and are not particularly limited in the present disclosure.

[0066] 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 resonators 200 adjacent to each other in a first direction (x direction) are formed. Each laser resonator 200 has a stripe structure extending in a second direction (y direction) orthogonal to the first direction (x direction).

[0067] A waveguide structure for confining light is formed on the stacked growth layer 120, and the cleavage surfaces at both ends of the waveguide structure serve as reflectors to form a Fabry-Perot type laser resonator 200. In this example, four laser resonators 200_1 to 200_4 are formed, and a light beam is radiated from the emission end surface in the y direction. The end surface of each laser resonator is coated to give a desired reflectivity.

[0068] The waveguide structure may be, for example, a buried ridge waveguide.

[0069] Alternatively, the waveguide structure may be a CSP (Channeled Substrate Planer) structure in which a groove is formed on the N-type semiconductor substrate 110 along the waveguide and the thickness of the N-type cladding layer 122 in the groove portion is relatively thick.

[0070] The buried ridge structure and the CSP structure are waveguide structures using a refractive index distribution, but the present disclosure is not limited thereto, and a gain waveguide structure using a gain distribution may also be used. These structures are light confinement structures and can also be understood as current crowding structures.

[0071] A power supply electrode (P-side electrode) 150 is formed on the upper surface of the laser resonator 200. In order to independently drive the laser resonator 200, the power supply electrodes 150 are electrically insulated from each other, and the P-type semiconductor portion has a resistor between each emitter, so that it can be electrically independently driven. In this embodiment, the power supply electrode 150 is a stripe-shaped electrode extending in the y direction on the upper surface of the laser resonator 200.

[0072] In order to supply 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 wirings Lc1 to Lc4 are provided corresponding to the plurality of laser resonators 200_1 to 200_4 .

[0073] A plurality of electrode pads Pe1 to Pe4 are formed in pad regions 104 and 106 adjacent to the laser region 102 in the x direction. Bonding wires are connected to the electrode pads Pe1 to Pe4 in the case of junction-up mounting, and solder is connected in the case of junction-down mounting.

[0074] Each connection wiring 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.

[0075] For the inner two (200_2, 200_3) of the plurality of 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 stacked wiring structure 160 at a position intersecting with the laser resonator 200_1. The stacked wiring structure 160 includes an interlayer insulating film 162 formed between the connection wiring Lc2 and the power supply electrode 150.

[0076] Similarly, the connection wiring Lc3 crosses the laser resonator 200_4. The connection wiring Lc4 has a laminated wiring structure 160 at a position intersecting with the laser resonator 200_4.

[0077] As the material of the interlayer insulating film 162, inorganic materials such as SiO2 and organic materials such as polyimide can be used. SiO2 is easy to be thinned, so it is advantageous from the perspective of heat dissipation. Polyimide can fill the unevenness of the substrate and the surface can be easily flattened, so it has the advantages of being able to flatten the connection wiring Lc and improve the coverage of the film, but it is difficult to form it thinly, so it is difficult to cleave and granulate.

[0078] In the present 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 wiring Lc2 and Lc3. The height can be determined as the distance from a reference plane orthogonal to the z-axis, for example, the surface or back surface of the N-type semiconductor substrate 110 can be used as the reference plane. Preferably, the difference Δh between the height of the thick film pad 170 and the height of the stacked wiring structure 160 is greater than 1 μm, and more preferably greater than 5 μm.

[0079] In the present 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, the electrode pads Pe1 to Pe4 are formed thicker than ordinary electrode pads so as to function as the thick film pad 170 .

[0080] Figure 3 yes Figure 2 1 is a cross-sectional view of a semiconductor laser element 100. The 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 resistance region 204 formed by, for example, ion implantation is formed between adjacent laser resonators 200. A contact insulating film 154 is formed on the stacked growth layer 120, and the contact insulating film 154 opens at the lower surface of the power supply electrode. The contact insulating film 154 is formed of, for example, a material such as SiO2.

[0081] 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. In addition, 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.

[0082] The above is the structure of the semiconductor laser element 100. Next, its advantages will be described.

[0083] Figure 4 It is for Figure 2 FIG. 1 is a diagram showing a coating process of a semiconductor laser element 100. LD bars 6 including a plurality of semiconductor laser elements 100 are cut out from a wafer. The LD bars 6 are sandwiched, supported, and fixed by spacers 2. In this state, the end faces of the semiconductor laser elements 100 are subjected to coating treatment.

[0084] The semiconductor laser element 100 contacts the spacer 2 at the thick film pad 170 having the highest height, and the stacked wiring structure 160 does not contact the spacer 2. Therefore, the pressure applied to the stacked wiring structure 160 can be reduced, and the reliability of the semiconductor laser element 100 can be prevented from being reduced.

[0085] Next, an example of mounting the semiconductor laser element 100 will be described.

[0086] Figure 51 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 base) 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, the N-side electrode 152 is mounted toward the support substrate 310 side.

[0087] The electrode pads Pe2 and Pe3 are connected to the lead (anode) of the package (not shown) or the anode of the driving circuit via bonding wires 320_2 and 320_3. In addition, the N-side electrode 152 is connected to the electrode 312 formed on the support substrate 310 via solder 322. The electrode 312 is connected to the lead (cathode) of the package (not shown) or the cathode of the driving circuit via bonding wires 324.

[0088] Figure 6 4 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, mounted in an orientation in which the power supply electrode 150 faces the support substrate 410 side.

[0089] A plurality of substrate-side electrode pads 412_1 to 412_4 corresponding to the plurality of laser resonators 200_1 to 200_4 are formed on the support substrate 410. Figure 6 In the cross-sectional view of , only two substrate-side electrode pads 412_2 to 412_3 are shown. The electrode pads Pe2 and Pe3 are connected to the substrate-side electrode pads (hereinafter 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 the package not shown or the anode of the drive circuit via bonding wires 422_2 and 422_3, respectively. In addition, the N-side electrode 152 is connected to the lead (cathode) of the package not shown or the cathode of the drive circuit via a bonding wire 424.

[0090] like Figure 6 As shown, the electrode pads Pe3 and Pe4 as thick film pads play a role in preventing the laminated wiring structure 160 from contacting the supporting substrate 410 when the device is mounted in a junction-down manner.

[0091] Figure 7 1 is a cross-sectional view of a laser device including a semiconductor laser element 100 . Figure 7 and Figure 6 Similarly, this is an example of installation with the knot facing downward. Figure 7In the embodiment, the substrate-side electrode pad 412_2 corresponding to each laser cavity 200_2 is formed to overlap with the electrode pad Pe2 and the connection wiring Lc2 of the corresponding laser cavity. 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 is true for the connection wiring Lc3 side.

[0092] according to Figure 7 The composition of Figure 6 Compared with the structure of , the heat dissipation can be improved.

[0093] (Implementation Method 2)

[0094] Figure 8 FIG. 1 is a perspective view of a semiconductor laser element 100A according to Embodiment 2. In Embodiment 1, the electrode pads Pe1 to Pe4 also serve as the thick film pads 170. Figure 8 In the embodiment, the thick film pad 170A is formed independently of the electrode pads Pe1 to Pe4. In this configuration, the thick film pad 170A may be a metal or an insulator. When the thick film pad 170A is formed of an insulator, it can be formed using the same material as the interlayer insulating film 162 and the same film forming process.

[0095] The function of the thick film pad 170A is to prevent the laminated wiring structure 160 from contacting the spacer during the coating process, and the thick film pad 170A can be used in the form of an LD strip. Figure 8 As shown, when the thick film pad 170A is formed only in the pad region 104 on one side, the thick film pad 170A similarly formed in the other adjacent chip exhibits the same function.

[0096] Of course, additional thick film pads 170A may be formed.

[0097] (Implementation 3)

[0098] Fig. 9 1 is a perspective view of a semiconductor laser element 100B according to Embodiment 3. In the semiconductor laser element 100B, the pad region 104 is provided only on one side of the chip, and the laser region 102 is provided close to the opposite side. All four electrode pads Pe1 to Pe4 are formed in the pad region 104 .

[0099] The connection wiring Lc2 has a laminated wiring structure 160 at the intersection with the power supply electrode 150_1. The connection wiring Lc3 has a laminated wiring structure 160 at the intersection with the power supply electrodes 150_2 and 150_3. The connection wiring Lc4 has a laminated wiring structure 160 at the intersection with the power supply electrodes 150_2, 150_3, and 150_4.

[0100] (Implementation 4)

[0101] Figure 8 The semiconductor laser element 100A of Fig. 9 If the semiconductor laser element 100B is mounted in a junction-down manner, it becomes a cantilever beam structure, and therefore, when the lateral width of the chip is wide, the structure is unstable. In the fourth embodiment, a structure suitable for mounting in a junction-down manner is described.

[0102] Fig.10 FIG. 1 is a perspective view of a semiconductor laser element 100C according to a fourth embodiment. Fig. 9 The semiconductor laser element 100B further includes electrode pads Pe1' to Pe4' as thick film pads 170. The electrode pads Pei' (i=1, 2, 3, 4) are adjacent to the electrode pad Pei in the x direction and are electrically connected to each other.

[0103] According to this configuration, in the case of junction mounting, the semiconductor laser element 100 can be supported by the electrode pad Pe′ in addition to the electrode pad Pe, so that the structural strength can be improved.

[0104] (Implementation method 5)

[0105] Fig.11 is a perspective view of a semiconductor laser device 100D according to Embodiment 5. The lateral width (width in the x direction) of the electrode pad Pe is Fig. 9 This can also be understood as Fig.10 The electrode pads Pe and Pe' are continuously formed integrally. According to this structure, in the case of junction mounting, the semiconductor laser element 100 can be supported by the wide electrode pads Pe, so that the structural strength can be improved.

[0106] (Implementation 6)

[0107] Fig.12 FIG. 1 is a perspective view of a semiconductor laser element 100E according to Embodiment 6. The semiconductor laser element 100E is Fig. 9 The semiconductor laser element 100B is formed by adding a plurality of thick film pads 170E. 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 the support substrate when the semiconductor laser element 100 is mounted in a junction-down manner. However, the thick film pads 170E do not contribute to the driving of the semiconductor laser element 100, and therefore do not need to be electrically connected to the laser resonators 200_1 to 200_4.

[0108] According to this structure, when the bracket is installed with the knot facing downward, since a cantilever beam structure is not formed, the structural strength can be improved.

[0109] (Implementation 7)

[0110] Fig.13 1 is a perspective view of a semiconductor laser element 100F according to Embodiment 7. The semiconductor laser element 100F is a 6-beam (6-emitter) device having 6 laser resonators 200_1 to 200_6 and 6 electrode pads Pe1 to Pe6. The electrode pads Pe1 to Pe6 are thick film pads 170 arranged in two rows. Fig.10 Similar to the semiconductor laser element 100c, when mounted in a junction-down manner, the cantilever beam can be supported by the two rows of electrode pads Pe, thereby improving the structural strength. Fig.13 The configuration is effective when the resonator length, that is, the length of the chip in the y direction is short.

[0111] Fig.14 : is a perspective view of a semiconductor laser element 100a of 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 the connection wiring Lc6. The plurality of electrode pads Pe6 may be arranged in the x direction or in the y direction.

[0112] (Implementation 8)

[0113] Fig.15 This is a perspective view of a semiconductor laser element 100G according to Embodiment 8. In the semiconductor laser element 100G, six electrode pads Pe1 to Pe6 are arranged in three rows. This configuration can further improve the strength when mounted in a junction-down manner. This is also effective when the resonator length, that is, the length of the chip in the y direction, is short.

[0114] In the first to seventh embodiments described above, the interlayer insulating film 162 is formed independently for each connection wiring Lc. Fig.15 As shown, the interlayer insulating film 162 may also be formed continuously.

[0115] Several examples will be described regarding the formation range of the interlayer insulating film 162 .

[0116] (Implementation method 9)

[0117] Fig.16 1 is a top view of a semiconductor laser element 100H according to Embodiment 9. The interlayer insulating film 162 is provided only at locations where the connection wiring Lc and the power supply electrode 150 intersect and require insulation. In this configuration, the interlayer insulating film 162 may be formed of SiO 2 or polyimide.

[0118] (Implementation 10)

[0119] Fig.17It is a top view of the semiconductor laser element 100I of the tenth embodiment. The interlayer insulating film 162 is formed widely over the range where a plurality of connection wirings Lc are formed, and is formed in an area that does not cover the electrode pad. However, the interlayer insulating film 162 is not formed near the end face of the resonator, and becomes a structure that is easy to cleave and granulate. In this structure, the interlayer insulating film 162 covers substantially the entire area of ​​the laser region 102, and can prevent electrical short circuits between the power supply electrodes 150_i. In the manufacturing process and assembly process of a narrow-pitch multi-beam laser, it is also more effective in preventing electrical short circuits caused by the adhesion of conductive foreign matter. In addition, it is possible to obtain heat dissipation brought by the interlayer insulating film itself, and heat dissipation effect on the connection wiring brought by obtaining a wide area of ​​the connection wiring provided thereon. The interlayer insulating film 162 has an opening 164_i at the location where the connection wiring Lc_i (i=1,2,3,4) is to be connected to the power supply electrode 150_i. In this configuration, the interlayer insulating film 162 may be formed of either SiO 2 or polyimide.

[0120] (Implementation 11)

[0121] Fig.18 1 is a top view of a semiconductor laser element 100J according to Embodiment 11. An interlayer insulating film 162 is formed over a wide range including electrode pads Pe1 to Pe4, and connection wiring Lc and electrode pads Pe are formed on the interlayer insulating film 162. However, it is not formed on the periphery of the N-type semiconductor substrate 110, making it easy to cleave and granulate. In this structure, there is no boundary of the interlayer insulating film 162 between the laser region and the pad region, so it is possible to prevent the coverage of the connection wiring Lc at the boundary step from being reduced. In this structure, the interlayer insulating film 162 can also be formed of either SiO2 or polyimide.

[0122] (Implementation 12)

[0123] Fig.19 1 is a top view of a semiconductor laser element 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 formed of polyimide, it is difficult to cleave and granulate, so a material that can be thinned, such as SiO2, is preferably selected as the material of the interlayer insulating film 162.

[0124] (Implementation 13)

[0125] As reference Figure 4As described above, by providing the thick film pad 170, it is possible to prevent the collision between the stacked wiring structure 160 and the spacer 2, but on the contrary, 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, there is a possibility that the coated material passes through the gap and goes around to the end face on the opposite side and adheres. If the undesired coated material adheres to the end face on the opposite side, it may cause manufacturing deviation or fail to obtain the designed reflection characteristics. In embodiment 13, a technology for solving this problem is described.

[0126] Fig. 20 It is a three-dimensional view of the semiconductor laser element 100L of embodiment 13. The semiconductor laser element 100L includes a prevention wall 180 in addition to the thick film pad 170. The prevention wall 180 crosses the plurality of laser resonators 200_1 to 200_4 along the x direction and is formed at least over 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 a metal or an insulator. When the prevention wall 180 is a metal, an insulating layer is inserted between the prevention wall 180 and the power supply electrode 150. In addition, the prevention wall 180 may be the same material as the thick film pad 170 or a different material.

[0127] According to the semiconductor laser element 100L, the wall 180 is prevented from coming into contact with the spacer 6 during the coating step, so that the coating material can be prevented from bypassing.

[0128] Fig.21 Yes means Fig. 20 A top view of an embodiment of a semiconductor laser element 100L. The interlayer insulating film 162 and Fig.18 The semiconductor laser element 100J is similar to the semiconductor laser element 100J and is formed in a wide range except for the outer periphery of the N-type semiconductor substrate 110.

[0129] 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 the same process as the connection wiring Lc. On the wiring layer 182, the prevention wall 180 is formed using the same material and the same process as the electrode pads Pe.

[0130] Fig. 22 yes Fig.21 FIG. 1 is a cross-sectional view of a semiconductor laser element 100L. Fig. 22 The upper layer is Fig.21 AA line section diagram, the lower layer is Fig.21 BB line cross-section diagram.

[0131] (Implementation 14)

[0132] Fig.23 1 is a perspective view of a semiconductor laser element 100M according to Embodiment 14. The preventing wall 180 is formed integrally and continuously with one or more (in this example, the electrode pad Pe1) of the plurality of electrode pads Pe1 to Pe4.

[0133] (Manufacturing method)

[0134] Next, a method for manufacturing the semiconductor laser element 100 in which the electrode pad Pe also serves as the thick film pad 170 will be described. This manufacturing method includes a plating step of forming the thick film pad 170 by electroplating.

[0135] Fig.24 1 is a diagram for explaining a method of manufacturing semiconductor laser element 100 . Power supply electrode 150 of semiconductor laser element 100 is continuous with power supply electrode 150 of adjacent semiconductor laser element 100 , and is electrically connected to plating power supply pins 502 and 504 provided on the outer periphery of wafer 500 .

[0136] In the electroplating process, a photoresist is applied on the wafer 500. The photoresist is opened in the electroplating film forming area. For example, in the case of electroplating the thick film pad, an opening is made in the formation position of the thick film pad 170, that is, the position of the electrode pads Pe1 to Pe4. The wafer 500 is immersed in the electroplating solution, and power is supplied to the electroplating power supply pins 502 and 504 from the outside. Thus, power is supplied to the electrode pad Pe via the power supply electrode 150 and the connecting wiring Lc, and a film is formed by electroplating on the electrode pad Pe, so that the thick film pad 170 can be formed. That is, the process of providing an additional power supply electrode wiring for supplying power to the thick film pad and removing unnecessary power supply electrode wiring after electroplating can be omitted, and the manufacturing cost can be reduced. This manufacturing method can also be used in the case where electroplating is desired to increase the film thickness of the connecting wiring portion. In this case, the photoresist is opened in the connection wiring portion, and power is supplied to the connection wiring portion formed thinly in advance by vapor deposition or the like through the power supply electrode 150, so that a film is formed on the connection wiring portion by electroplating.

[0137] exist Fig.23 In the semiconductor laser element 100M, power is supplied to the electrode pad Pe and the wiring layer 182 of the base of the prevention wall 180 by the electroplating method, so that the prevention wall 180 can be formed simultaneously with the electrode pad Pe.

[0138] The embodiments merely illustrate the principles and applications of the present invention, and many modifications and changes in configuration are permitted in the embodiments without departing from the spirit of the present invention defined in the claims.

[0139] Description of Reference Numerals

[0140] 100 Semiconductor laser element

[0141] 102 Laser Area

[0142] 104, 106 pad area

[0143] 110 N-type semiconductor substrate

[0144] 120 Stacked Growth Layers

[0145] 122 N-type cladding

[0146] 124 P-type cladding

[0147] 130 Luminous Layer

[0148] Pe electrode pad

[0149] Lc connection wiring

[0150] 150 Power supply electrode

[0151] 152 N-side electrode

[0152] 154 Contact insulation film

[0153] 160 stacked wiring structure

[0154] 162 Interlayer insulation film

[0155] 170 Thick Film Pad

[0156] 180 Prevent wall

[0157] 200 Laser Resonator

[0158] 300 Semiconductor laser device

[0159] 310 Support substrate

Claims

1. A multi-beam semiconductor laser element, characterized in that: have: Three or more laser resonators are integrated adjacent to each other along a first direction in a laser region of a single semiconductor substrate, each laser resonator has an independent power supply electrode, and the end surface is coated along the second direction as the length direction; a plurality of electrode pads formed in a pad region adjacent to the laser region in the first direction and corresponding to the plurality of laser resonators; a plurality of connection wirings corresponding to the plurality of laser resonators, extending along the first direction respectively, electrically connecting the power supply electrodes of the corresponding laser resonators to the corresponding electrode pads, the connection wirings having a stacked wiring structure at positions intersecting the laser resonators; and A thick film pad is formed in the pad region and has a height higher than a height of the stacked wiring structure of the connection wiring.

2. The multi-beam semiconductor laser element according to claim 1, wherein: The thick film pad is formed of the same material as the electrode pad.

3. The multi-beam semiconductor laser element according to claim 1, wherein: The height of the electrode pad is higher than the height of the stacked wiring structure of the connecting wiring, and the electrode pad is the thick film pad.

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

5. 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. The multi-beam semiconductor laser element according to claim 5, wherein: The interlayer insulating film is polyimide.

7. The multi-beam semiconductor laser element according to claim 5 or 6, characterized in that: The thick film pad is formed of the same material as the interlayer insulating film.

8. The multi-beam semiconductor laser element according to any one of claims 1 to 5, characterized in that: The invention further includes a prevention wall formed on the plurality of laser cavities, extending in the first direction, and having substantially the same height as the thick-film pad.

9. The multi-beam semiconductor laser element according to claim 8, characterized in that: 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. The multi-beam semiconductor laser element according to any one of claims 1 to 5, characterized in that: There are a plurality of thick film pads, and the heights of the plurality of thick film pads are substantially equal.

11. The multi-beam semiconductor laser element according to any one of claims 1 to 5, characterized in that: The interval between the plurality of laser resonators is 100 μm or less.

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

13. A semiconductor laser device, characterized in that: have: The multi-beam semiconductor laser element according to any one of claims 1 to 5; and Support substrate, The multi-beam semiconductor laser element is mounted on the support substrate in a junction-down manner.

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

15. A manufacturing method, which is a manufacturing method of the multi-beam semiconductor laser element according to claim 1, characterized in that: The power supply electrode is a stripe electrode, The manufacturing method comprises a plating step of forming the connection wiring and the thick film pad by electroplating. The power supply in the electroplating step is performed via the stripe-shaped electrodes.

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