Edge-emitting semiconductor laser diode; semiconductor laser device manufacturing method and semiconductor laser device

Abstract

Edge-emitting semiconductor laser diodes; methods for manufacturing semiconductor laser devices and semiconductor laser devices. The present invention also provides a semiconductor layer sequence (2) having a first semiconductor layer (3) having a first conductivity type and a second semiconductor layer (4) having a second conductivity type, and an active region (5) configured to generate electromagnetic laser radiation (6) during operation, the active region (5) being disposed between the first semiconductor layer (3) and the second semiconductor layer (4); a ridge waveguide (8) provided on a major surface (9) of the semiconductor layer sequence (2); and a first electrical contact layer (1) disposed on the major surface (9) of the semiconductor layer sequence (2). 2), an edge-emitting semiconductor laser diode is provided, comprising a first electrical contact layer (12) that is in electrical contact with the first semiconductor layer (3), and a second electrical contact layer (13) that is arranged on the ridge waveguide (8), the second electrical contact layer (13) being in electrical contact with the second semiconductor layer (4), the first electrical contact layer (12) being arranged on the second electrical contact layer (13), so that electrical mounting areas (27) of the edge-emitting semiconductor laser diode (1) are arranged in a common plane (29).

Description

[Technical Field]

[0001] The present application provides an edge-emitting semiconductor laser diode, a method for manufacturing a semiconductor laser device, and a semiconductor laser device. Summary of the Invention [Problem to be solved by the invention]

[0002] Improved edge-emitting semiconductor laser diodes are provided, particularly edge-emitting semiconductor laser diodes that are easily integrated with photonic integrated circuits. Additionally, simplified methods of manufacturing semiconductor laser devices and improved semiconductor laser devices are provided. [Means for solving the problem]

[0003] These objects are achieved by an edge-emitting semiconductor laser diode having the features of claim 1, a method for manufacturing a semiconductor laser device having the steps of claim 14, and a semiconductor laser device having the features of claim 17.

[0004] Further embodiments and developments of the edge-emitting semiconductor laser diode, the method for manufacturing the semiconductor laser device, and the semiconductor laser device are described in the dependent claims.

[0005] According to one embodiment, an edge-emitting semiconductor laser diode comprises a semiconductor layer sequence having a first semiconductor layer having a first conductivity type and a second semiconductor layer having a second conductivity type. For example, the first conductivity type is n-conductivity type and the second conductivity type is p-conductivity type. In this case, the first semiconductor layer is an n-doped semiconductor layer and the second semiconductor layer is a p-doped semiconductor layer. It is also possible that the first conductivity type is p-conductivity type and the second conductivity type is n-conductivity type. In this case, the first semiconductor layer is p-doped and the second semiconductor layer is n-doped.

[0006] For example, the semiconductor layer sequence is based on nitride semiconductor compound materials and is configured to generate electromagnetic laser radiation, in particular in the ultraviolet to blue spectral range. Nitride compound semiconductor materials are compound semiconductor materials containing nitrogen, such as In, where 0≦x≦1, 0≦y≦1, and x+y≦1. x Al y Ga 1-x-y It is an N-based material.

[0007] According to a further embodiment of the edge-emitting semiconductor laser diode, an active region is disposed between the first semiconductor layer and the second semiconductor layer, the active region being configured to generate electromagnetic laser radiation during operation of the edge-emitting semiconductor laser diode.

[0008] According to yet another embodiment, the edge-emitting semiconductor laser diode comprises a ridge waveguide on a major surface of the semiconductor layer sequence. The ridge waveguide is particularly formed as a protrusion on the major surface of the semiconductor layer sequence and is configured to guide electromagnetic laser radiation. For example, the height of the ridge waveguide does not exceed 800 nanometers. In particular, a side surface of the ridge waveguide, which forms part of a facet of the edge-emitting semiconductor laser diode, comprises an optical exit region of the semiconductor layer sequence, which emits electromagnetic laser radiation during operation.

[0009] The main surface of the semiconductor layer sequence has a normal corresponding to the growth direction of the semiconductor layers of the semiconductor layer sequence, and the ridge waveguide extends in particular in a longitudinal direction parallel to the main surface, in particular in a direction corresponding to the propagation direction of the electromagnetic laser radiation.

[0010] According to yet another embodiment, the edge-emitting semiconductor laser diode comprises a first electrical contact layer disposed on a major surface of the semiconductor layer sequence and in electrical contact with the first semiconductor layer. In particular, the first electrical contact layer comprises or consists of a metal. For example, the thickness of the first electrical contact layer is between 200 nanometers and 3 micrometers, inclusive.

[0011] According to yet another embodiment, the edge-emitting semiconductor laser diode includes a second electrical contact layer disposed on the ridge waveguide and electrically contacting the second semiconductor layer. To provide electrical contact to the second semiconductor layer, the second electrical contact layer is particularly in at least partial direct contact with the second semiconductor layer. In particular, the second electrical contact layer includes or consists of a metal, such as Pd. For example, the thickness of the second electrical contact layer is between 20 nanometers and 200 nanometers, inclusive.

[0012] According to yet another embodiment of the edge-emitting semiconductor laser diode, the thickness of the second electrical contact layer is between 2% and 20% inclusive of the thickness of the first electrical contact layer.

[0013] According to yet another embodiment of the edge-emitting semiconductor laser diode, the first electrical contact layer is disposed on the second electrical contact layer, thereby causing the electrical mounting areas of the edge-emitting semiconductor laser diode to be coplanar. Those skilled in the art will appreciate that "coplanar electrical mounting areas" refers to within manufacturing tolerances. For example, the tops of the surfaces of the electrical mounting areas deviate from coplanarity by no more than 15%, no more than 5%, or no more than 2%.

[0014] The edge-emitting semiconductor laser diode is particularly based on the idea that a relatively thick first electrical contact layer, which is in electrical contact with the first semiconductor layer, is also disposed on a relatively thin second electrical contact layer to achieve electrical contact pads with flush electrical mounting areas, thus achieving a surface-mountable edge-emitting semiconductor laser diode.

[0015] In particular, edge-emitting semiconductor laser diodes are implemented as flip chips with electrical mounting areas on the same surface, which allow the electrical mounting areas to be mounted to other components, such as photonic integrated circuits, via a bonding layer, such as a solder. Edge-emitting semiconductor laser diodes with a flip chip design have the advantage that they do not require wire bonding for external electrical connections.

[0016] According to yet another embodiment, an edge-emitting semiconductor laser diode comprises: a semiconductor layer sequence having a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, and an active area configured to generate electromagnetic laser radiation during operation, the active area being disposed between the first and second semiconductor layers; a ridge waveguide at a major surface of the semiconductor layer sequence; a first electrical contact layer disposed on a major surface of the semiconductor layer sequence and in electrical contact with the first semiconductor layer; a second electrical contact layer disposed on the major surface of the ridge waveguide and in electrical contact with the second semiconductor layer; The first electrical contact layer is disposed on the second electrical contact layer, so that the electrical mounting areas of the edge-emitting semiconductor laser diode are disposed on the same plane.

[0017] According to yet another embodiment, the edge-emitting semiconductor laser diode includes an electrical insulating layer that electrically insulates a portion of the first electrical contact layer that is in electrical contact with the first semiconductor layer from a portion of the first electrical contact layer that is arranged on the second electrical contact layer. In particular, the first electrical contact layer is structured and has different, non-contiguous portions. In particular, the first electrical contact layer includes or consists of at least two portions that are arranged on the same plane but are not connected to each other, one portion in electrical contact with the first semiconductor layer and one portion that is arranged on the second electrical contact layer. The electrical insulating layer is also at least partially arranged on the same plane as the first electrical contact layer, and is arranged in the region between the two portions of the first electrical contact layer to electrically insulate them.

[0018] In particular, the electrically insulating layer is arranged in the opening of the first electrical contact layer and preferably completely fills said opening, e.g., the insulating layer is in direct contact with the semiconductor layer sequence in the opening of the first electrical contact layer.

[0019] According to yet another embodiment of the edge-emitting semiconductor laser diode, the electrical insulating layer is a distributed Bragg reflector (DBR). In particular, the distributed Bragg reflector extends over the first main surface of the semiconductor layer sequence and over the side surfaces of the semiconductor layer sequence, the side surfaces comprising the facets with the light exit surfaces of the edge-emitting semiconductor laser diode. In this case, the distributed Bragg reflector preferably forms a resonator for electromagnetic laser radiation on the facets of the edge-emitting semiconductor laser diode. In particular, the distributed Bragg reflector electrical insulating layer has a thickness on the side surfaces of the semiconductor layer sequence that is smaller than its thickness on the main surface, e.g., for process reasons.

[0020] For example, the thickness of the electrically insulating layer is at least 0.5 micrometers, at least 1 micrometer, or at least 3 micrometers across the major surface of the semiconductor layer sequence. On the side of the semiconductor layer sequence, the electrically insulating layer, which is a distributed Bragg reflector, has a thickness of, for example, at least 200 nanometers, at least 500 nanometers, or at least 900 nanometers. For example, the distributed Bragg reflector includes or consists of alternating layers of SiO2 and SiN. For example, the layers of the distributed Bragg reflector are deposited by PCVD (short for plasma-enhanced chemical vapor deposition).

[0021] According to yet another embodiment of the edge-emitting semiconductor laser diode, the electrical insulation layer has at least two openings, and the first electrical contact layer and the electrical pad layer are disposed in direct contact with each other within the openings, e.g., the electrical insulation layer is disposed between the first electrical contact layer and the electrical pad layer, excluding the openings, within the electrical contact pads.

[0022] According to yet another embodiment of the edge-emitting semiconductor laser diode, the ridge waveguide is partially disposed in at least one opening in the electrical insulating layer. In particular, the electrical insulating layer is higher than the ridge waveguide in the vertical direction. That is, the thickness of the electrical insulating layer is greater than the height of the ridge waveguide. In this way, the ridge waveguide is protected, particularly during bonding with other elements. Particularly preferably, a first electrical contact layer is disposed over the ridge waveguide at least in the opening, which further protects the ridge waveguide and promotes heat dissipation during operation. Furthermore, an electrical pad layer is preferably disposed in the opening, e.g., in direct contact with the first electrical contact layer.

[0023] If the ridge waveguide is partially disposed within at least one opening in the electrical insulating layer and the ridge waveguide is covered with a first electrical contact layer, the electrical insulating layer preferably exceeds the first electrical contact layer, and if an electrical pad layer is provided covering the first electrical contact layer, the electrical insulating layer preferably also exceeds the electrical pad layer.

[0024] In particular, the ridge waveguide is covered in at least one opening of the electrical insulating layer by a second electrical contact layer, a first electrical contact layer, and an electrical pad layer, where the second electrical contact layer is preferably arranged between the ridge waveguide and the first electrical contact layer. In particular, over the ridge waveguide, the following layers are arranged in direct contact with each other in the following order: - a second electrical contact layer, a first electrical contact layer, -Electrical pad layer.

[0025] According to yet another embodiment of the edge-emitting semiconductor laser diode, the semiconductor layer sequence is provided with a via extending from the main surface through the semiconductor layer sequence. For example, the via extends completely through the semiconductor layer sequence to the substrate on which the semiconductor layer sequence is mounted. This is particularly the case when the substrate is electrically conductive. It is also possible for the via to extend only through the semiconductor layer sequence to the first semiconductor layer. In particular, within the via, the first electrical contact layer is in direct physical contact with the first semiconductor layer and / or the substrate. In particular, the via runs parallel to the ridge waveguide.

[0026] According to yet another embodiment of the edge-emitting semiconductor laser diode, the via runs parallel to the ridge waveguide and divides the semiconductor layer sequence into a first region and a second region in a plan view of the main surface of the semiconductor layer sequence, which shape provides a good current distribution within the semiconductor layer sequence.

[0027] According to yet another embodiment of the edge-emitting semiconductor laser diode, the electrical pad layer is at least partially constituted by at least one first electrical contact pad and at least one second electrical contact pad, the first electrical contact pad being arranged in the first region and the second electrical contact pad being arranged in the second region, in particular the first electrical contact pad being configured to be in external electrical contact with the first semiconductor layer and the second electrical contact pad being configured to be in external electrical contact with the second semiconductor layer.

[0028] Particularly preferably, the surface of the first electrical contact pad and the surface of the second electrical contact pad constitute or form the electrical mounting area of ​​the edge-emitting semiconductor laser diode.

[0029] According to yet another embodiment of the edge-emitting semiconductor laser diode, the first and / or second electrical contact pads have a circular shape in plan view on the main surface of the semiconductor layer sequence. For example, the edge-emitting semiconductor laser diode has three first electrical contact pads arranged in a first region of the semiconductor layer sequence and three second electrical contact pads arranged in a second region of the semiconductor layer sequence. In particular, the three first electrical contact pads are arranged in a straight line parallel to the ridge waveguide and the edge of the edge-emitting semiconductor laser diode. Furthermore, the three second electrical contact pads are particularly preferably arranged in a straight line parallel to the ridge waveguide and the edge of the edge-emitting semiconductor laser diode.

[0030] According to yet another embodiment of the edge-emitting semiconductor laser diode, an electrical insulating layer is arranged at least partially on or over the semiconductor layer sequence. The electrical insulating layer has at least one recess in the boundary region. In particular, the main surface of the semiconductor layer sequence is freely accessible at the recess. This has the advantage that the surface is very well defined for the ridge waveguide with the light exit region of the edge-emitting semiconductor laser diode.

[0031] The edge-emitting semiconductor laser diode is configured to be part of a semiconductor laser device. A method for manufacturing the semiconductor laser device and the semiconductor laser device are described below. Features and embodiments described with respect to the edge-emitting semiconductor laser diode may also be embodied in the semiconductor laser device and the method for manufacturing the semiconductor laser device, and vice versa.

[0032] According to an embodiment of the method for manufacturing a semiconductor laser device, in particular as described above, an edge-emitting semiconductor laser diode is provided. In particular, the edge-emitting semiconductor laser diode has at least two electrical mounting areas on the same surface. That is, the edge-emitting semiconductor laser diode is implemented as a flip chip. Preferably, the electrical mounting areas of the edge-emitting semiconductor laser diode are arranged on the same plane.

[0033] According to an embodiment of the method, a photonic integrated circuit having external mounting pads is provided, in particular the photonic integrated circuit having at least two external mounting pads configured to mount an edge-emitting semiconductor laser diode to the external mounting pads via its electrical mounting region.

[0034] According to yet another embodiment of the method, the electrical mounting area of ​​the edge-emitting semiconductor laser diode is mechanically stable and electrically conductively connected to an external mounting pad.

[0035] According to yet another embodiment of the method, an electrical insulating layer is arranged at least partially on or over the semiconductor layer sequence. The electrical insulating layer has at least one cutout in the boundary region. Preferably, the main surface of the semiconductor layer sequence is freely accessible at the cutout. Furthermore, the photonic integrated circuit has at least one z-alignment structure inserted in the cutout between the electrical mounting area of ​​the edge-emitting semiconductor laser diode and the connection with the external mounting pad. The z-alignment structure of the photonic integrated circuit is configured in particular for alignment of the edge-emitting semiconductor laser diode at least in the growth direction of the semiconductor layer sequence.

[0036] According to yet another embodiment of the method, connecting the electrical mounting area of ​​the edge-emitting semiconductor laser diode to the external mounting pad includes disposing solid solder that at least partially forms the external mounting pad and disposing the electrical mounting area of ​​the edge-emitting semiconductor laser diode offset onto the solid solder. In particular, the solid solder is liquefied, especially after the electrical mounting area of ​​the edge-emitting semiconductor laser diode is disposed on the solid solder. The liquefaction is achieved, for example, by a reflow process. In particular, the liquid solder wets the electrical mounting area of ​​the edge-emitting semiconductor laser diode, and the liquid solder moves the edge-emitting semiconductor laser diode, thereby self-aligning the optical exit area of ​​the edge-emitting semiconductor laser diode with the active optical element of the photonic integrated circuit. In particular, the circular shape of the electrical contact pad of the edge-emitting semiconductor laser diode allows for controlled movement of the edge-emitting semiconductor laser diode during the self-alignment process.

[0037] In particular, during reflow of the liquid solder, the surface tension of the liquid solder, e.g., capillary forces, cause the edge-emitting semiconductor laser diode to move, whereby the z-alignment structure helps to limit such movement and self-align the edge-emitting semiconductor laser diode.

[0038] In addition to the z-direction alignment structure disposed on the photonic integrated circuit, the edge-emitting semiconductor laser diode can have at least one x-direction alignment structure and at least one y-direction alignment structure that constrain its movement in the x-direction and the y-direction, where the x-direction and the y-direction form planes parallel to the major surfaces of the semiconductor layer sequence. Furthermore, the y-direction corresponds to the longitudinal direction. For example, the x-direction alignment structure, the y-direction alignment structure, and / or the z-direction alignment structure are fabricated by lithography. With the aid of the x-direction alignment structure and / or the y-direction alignment structure integrated on the edge-emitting semiconductor laser diode, high positioning accuracy can be achieved during the fabrication of the semiconductor laser device.

[0039] For example, y-direction alignment structures are disclosed in German application DE 102022106009.8, which is incorporated herein by reference.

[0040] The active optical element is, for example, an optical waveguide. During self-alignment of the edge-emitting semiconductor laser diode, the optical exit area is, for example, positioned at the optical entrance area of ​​the optical waveguide. In particular, the optical exit area of ​​the edge-emitting semiconductor laser diode covers the optical entrance area of ​​the optical waveguide.

[0041] The self-alignment process is based on the idea that an edge-emitting semiconductor laser diode is positioned offset with respect to its final position on a photonic integrated circuit, moved to its final position by the restoring force of the liquid solder, and guided by the alignment structures to be aligned vertically by the z-direction alignment structures, in the x-direction by the x-direction alignment structures, and longitudinally by the y-direction alignment structures, thereby facilitating the fabrication of semiconductor laser devices by precisely aligning elements of the photonic integrated circuit, such as the optical entrance face of an optical waveguide, with the optical exit face of the edge-emitting semiconductor laser diode.

[0042] According to one embodiment, the semiconductor laser device comprises an edge-emitting semiconductor laser diode, which in operation emits electromagnetic laser radiation from an optical exit area.

[0043] According to yet another embodiment, the semiconductor laser device includes a photonic integrated circuit having an active optical element aligned with the optical exit region of the edge-emitting semiconductor laser diode, in particular, the optical exit region overlaying the optical entrance region of the active optical element.

[0044] According to yet another embodiment of the semiconductor laser device, an electrically insulating layer is arranged at least partially on the semiconductor layer sequence, for example a distributed Bragg reflector that is also arranged on the facet, in particular the light exit region, of the edge-emitting semiconductor laser diode.

[0045] The electrically insulating layer preferably has at least one cutout in the boundary region, and the photonic integrated circuit has at least one z-alignment structure inserted into the cutout, preferably exactly one z-alignment structure inserted into each cutout.

[0046] For example, the z-alignment structures are posts that extend from the major surface of the photonic integrated circuit into the notch.

[0047] Edge-emitting semiconductor laser diodes and semiconductor laser devices may have applications in data encryption, data security, random number generation, visualization, augmented reality, or virtual reality. For example, edge-emitting semiconductor laser diodes and semiconductor laser devices are part of displays, communication devices, or detection devices.

[0048] In particular, a surface-mountable edge-emitting semiconductor laser diode is configured to be mounted in a self-aligned process to a photonic integrated circuit with the aid of alignment structures, particularly z-alignment structures.

[0049] Further advantageous embodiments and developments of the edge-emitting semiconductor laser diode, the method for manufacturing the semiconductor laser device, and the semiconductor laser device result from the exemplary embodiments described below in conjunction with the drawings. [Brief explanation of the drawings]

[0050] [Figure 1] FIG. 1 shows a schematic plan view of an edge-emitting semiconductor laser diode according to an exemplary embodiment. [Figure 2] FIG. 2 schematically illustrates a cross-sectional view along line AA′ of the edge-emitting semiconductor laser diode according to the exemplary embodiment of FIG. [Figure 3] FIG. 3 shows a schematic diagram of a semiconductor layer sequence on a substrate according to an exemplary embodiment. [Figure 4] FIG. 4 shows a detailed schematic view of the portion indicated by B in FIG. [Figure 5] FIG. 5 shows a detailed schematic diagram of the portion indicated by C in FIG. [Figure 6] FIG. 6 shows an alternative exemplary embodiment of the portion designated B in FIG. [Figure 7] FIG. 7 shows a flowchart of a method for manufacturing a semiconductor laser device according to an exemplary embodiment. [Figure 8] FIG. 8 shows a schematic diagram of process steps according to the exemplary embodiment of FIG. [Figure 9] FIG. 9 is a schematic cross-sectional view taken along line AA′ of FIG. [Figure 10] FIG. 10 shows a schematic cross-sectional view of a process step according to the exemplary embodiment of FIG. [Figure 11] FIG. 11 shows a schematic cross-sectional view of a process step according to the exemplary embodiment of FIG. [Figure 12] FIG. 12 schematically illustrates a plan view of a semiconductor laser device according to an exemplary embodiment. [Figure 13] FIG. 13 is a schematic cross-sectional view taken along line AA′ in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0051] In the drawings, equal or similar elements and elements having the same function are designated with the same reference symbols. The drawings and the proportions of the elements shown therein are not to be considered as being drawn to scale. Rather, single elements, in particular layers, may be shown enlarged for better presentation and / or understanding.

[0052] The edge-emitting semiconductor laser diode 1 according to the exemplary embodiment of Figures 1 to 5 comprises a semiconductor layer sequence 2 having a first semiconductor layer 3 having a first conductivity type and a second semiconductor layer 4 having a second conductivity type (see Figures 2 and 3). Furthermore, the semiconductor layer sequence 2 comprises an active region 5 configured to generate electromagnetic laser radiation 6 during operation. The active region 5 is arranged between the first semiconductor layer 3 and the second semiconductor layer 4 (see Figure 3).

[0053] In this exemplary embodiment, the first semiconductor layer 3 is an n-doped semiconductor layer and has an n-type conductivity, while the second semiconductor layer 4 is a p-doped semiconductor layer and has a p-type conductivity. The semiconductor layer sequence 2 is disposed on a substrate 7. For example, the substrate 7 is a growth substrate for the semiconductor layer sequence 2, and the semiconductor layer sequence 2 is epitaxially grown on the substrate 7 along a growth direction 45. Currently, the substrate 7 comprises or consists of electrically conductive n-doped gallium nitride.

[0054] Furthermore, the edge-emitting semiconductor layer sequence 2 comprises a ridge waveguide 8, which is a protrusion on a major surface 9 of the semiconductor layer sequence 2 (see Figures 1, 2 and 5), which guides the electromagnetic laser radiation 6 within the ridge waveguide 8 along a longitudinal direction 46 during operation of the edge-emitting semiconductor laser diode 1.

[0055] The edge-emitting semiconductor laser diode 1 has side facets 10 which are currently formed by etching and not by a scribing and breaking process. The light exit area 11, which emits electromagnetic laser radiation 6 during operation, is constituted by one facet 10 in the region of the ridge waveguide 8 (see FIG. 5).

[0056] The edge-emitting semiconductor laser diode 1 comprises a first electrical contact layer 12 arranged on an insulating layer 47 arranged on a major surface 9 of the semiconductor layer sequence 2. The insulating layer is arranged between the semiconductor layer sequence 2 and the first electrical contact layer 12. The insulating layer 47 is configured to prevent the first electrical contact layer 12 from short-circuiting the first semiconductor layer 3 and the second semiconductor layer 4.

[0057] The edge-emitting semiconductor laser diode 1 according to the exemplary embodiment of Figures 1 to 5 further comprises a via 14 in the main surface 9 of the semiconductor layer sequence 2. The via 14 enables electrical contact of the first semiconductor layer 3 by the first electrical contact layer 12. As shown in Figure 4, the via 14 penetrates the semiconductor layer sequence 2 down to the substrate 7. In the via 14, the first electrical contact layer 12 is in direct contact with the substrate 7. The via 14 runs parallel to the ridge waveguide 8 along the longitudinal direction 46 and divides the semiconductor layer sequence 2 into a first region 15 and a second region 16 in a plan view of the main surface 9 (see Figure 1).

[0058] Within the via 14, a feedthrough 48 is disposed in the insulating layer 47, thereby allowing the first electrical contact layer 12 to make electrical contact with the first semiconductor layer 3. At this time, the first electrical contact layer 12 is an n-contact layer. For example, as shown in FIG. 5, a second electrical contact layer 13 is disposed on and in direct contact with the ridge waveguide 8. The second electrical contact layer 13 makes electrical contact with the second semiconductor layer 4. At this time, the second electrical contact layer 13 is a p-contact layer.

[0059] The edge-emitting semiconductor laser diode 1 further includes an electrical pad layer 17. As shown in Fig. 1, the electrical pad layer 17 is configured to at least partially include three first electrical contact pads 18 and three second electrical contact pads 19 (each having a circular shape). The three first electrical contact pads 18 are arranged along a straight line parallel to the via 14 and the ridge waveguide 8. The three second electrical contact pads 19 are also arranged on a straight line parallel to the ridge waveguide 8 and the via 14.

[0060] The edge-emitting semiconductor laser diode 1 further comprises an electrical insulating layer 20, which is currently a distributed Bragg reflector 21. The electrically insulating layer 20, realized as a distributed Bragg reflector 21, covers the entire main surface 9 of the semiconductor layer sequence 2 and also the side surfaces of the semiconductor layer sequence 2. In particular, the facet 10 of the edge-emitting semiconductor laser diode 1 is covered by the distributed Bragg reflector 21. In particular, the front surface 22 of the ridge waveguide 8 and the back surface 23 of the ridge waveguide 8 are completely covered by the distributed Bragg reflector 21, thereby forming a resonator 24 for the electromagnetic laser radiation 6 generated in the active region 5 of the semiconductor layer sequence 2. The resonator 24 has an optical axis 25 extending along the ridge waveguide 8 parallel to the longitudinal direction 46. In particular, the distributed Bragg reflector 21 is highly reflective for the electromagnetic laser radiation 6.

[0061] In particular, the first electrical contact layer 12 is in direct contact with the n-conducting substrate 7 in a via 14 (see FIG. 4). Since the substrate 7 is electrically conductive, the first electrical contact layer 12 in direct contact with the substrate 7 is in electrical contact with the first semiconductor layer 3 in direct contact with the substrate 7. In the direct contact, an electrical insulating layer 20 is disposed on the first electrical contact layer 12 in the via 14.

[0062] The first electrical contact layer 12 is structured such that a portion of the first electrical contact layer 12 is arranged in a first region 15, a second portion of the first electrical contact layer 12 is arranged in a second region 16, and gaps are arranged between the portions of the first electrical contact layer 12. An electrical insulating layer 20 fills the gaps and electrically insulates the portions of the first electrical contact layer 12 from each other (see FIG. 2).

[0063] Furthermore, the electrical insulation layer 20 has openings 26. Three of the openings 26 in the electrical insulation layer 20 are disposed in the first region 15, while three of the openings 26 in the electrical insulation layer 20 are disposed in the second region 16. Within the openings 26, the electrical pad layer 17 and the first electrical contact layer 12 are disposed in direct contact with each other.

[0064] A ridge waveguide 8 is partially arranged in an opening 26 located in the second region 16 of the semiconductor layer sequence 2 (see Figures 2 and 5). The electrically insulating layer 20 has a height above the ridge waveguide 8 in the vertical direction 45 in order to protect the ridge waveguide 8. A second electrical contact layer 13 is arranged on the ridge waveguide 8 in direct contact with the semiconductor layer sequence 2.

[0065] An insulating layer 47 is arranged on the semiconductor layer sequence 2 to prevent the first electrical contact layer 12 from short-circuiting the first semiconductor layer 3 and the second semiconductor layer 4. A feedthrough 48 is further arranged in the insulating layer 47 to allow electrical contact between the second electrical contact layer 13 and the first electrical contact layer 12 (see FIG. 5).

[0066] Furthermore, the first electrical contact layer 12 completely covers the ridge waveguide 8 within the opening 26. The electrical pad layer 17 also completely covers the ridge waveguide 8. Furthermore, the arrangement of the first electrical contact layer 12, the electrical insulating layer 20, and the electrical pad layer 17 is symmetrical with respect to the via 14 in the region of the electrical contact pads 17, 18 (see FIG. 2).

[0067] The surface of the electrical pad layer 17 forms an electrical mounting area 27 of the edge-emitting semiconductor laser diode 1, which is configured to be mechanically and / or electrically conductively connectable to an external mounting pad 28. The arrangement of the first electrical contact layer 12, the electrical insulating layer 20 and the electrical pad layer 17 in the first region 15 and the second region 16 of the semiconductor layer sequence 2 is particularly symmetrical, resulting in the electrical mounting area 27 being arranged in a common plane 29.

[0068] Furthermore, the electrically insulating layer 20 has three cutouts 30 in a border area 31 which now have a round, e.g. oval or circular, shape in plan view (see FIG. 1). The cutouts 30 in the electrically insulating layer 20 expose the main surface 9 of the semiconductor layer sequence 2 (see FIG. 2).

[0069] The edge-emitting semiconductor laser diode 1 according to the exemplary embodiment of FIG. 6 is implemented identically to, for example, the edge-emitting semiconductor laser diode 1 according to the exemplary embodiment of FIGS. 1 to 5 , but differs only in the shape of the via 14. In contrast to the edge-emitting semiconductor laser diode 1 according to FIGS. 1 to 5 , the via 14 according to FIG. 6 does not penetrate completely through the semiconductor layer sequence 2 to the substrate 7, but only through the second semiconductor layer 4 to the first semiconductor layer 3. In the via 14, the first electrical contact layer 12 is in electrical contact with the first semiconductor layer 3. The exemplary embodiment of the via 14 according to FIG. 6 for the electrical connection of the first semiconductor layer 3 is particularly reasonable when a non-conductive substrate 7, such as a sapphire substrate, is used, or when the first semiconductor layer 3 has a higher lateral conductivity than the substrate, allowing for good current spreading within the semiconductor layer sequence 2.

[0070] 7 to 11, in a first step S1 an edge-emitting semiconductor laser diode 1 is provided. The edge-emitting semiconductor laser diode 1 is implemented, for example, as already described in FIGS.

[0071] In the next step S2, a photonic integrated circuit 32 is provided. For example, the photonic integrated circuit 32 includes or is made of silicon. The photonic integrated circuit 32 has a base region 33 that is larger than the edge-emitting semiconductor laser diode 1 and an extension plane parallel to the main surface 9 of the semiconductor layer sequence 2 (see Figures 8 and 9). In end surface regions 34 surrounding a central region 35 of the photonic integrated circuit 32, the photonic integrated circuit 32 forms a frame-like elevation. The photonic integrated circuit 32 has z-direction alignment structures 37 that are pillars extending from the main surface 49 of the photonic integrated circuit 32 in the vertical direction 45.

[0072] Additionally, the photonic integrated circuit 32 includes an active optical element 39 which is currently an optical waveguide having an optical entrance region 40 .

[0073] A structured seed layer 50 for the deposition of solid solder 42 is applied onto the major surface 49 of the photonic integrated circuit 32. The solid solder 42 is deposited onto the seed layer 50, for example by electrolytic means, and the solid solder 42 at least partially forms the external mounting pads 28 of the photonic integrated circuit 32.

[0074] In particular, the solid solder 42 and the electrical mounting area 27 of the edge-emitting semiconductor laser diode 1 are currently circular. The diameter of the electrical mounting area 27 of the edge-emitting semiconductor laser diode 1 is larger than the diameter of the solid solder 42 (see FIG. 10).

[0075] In the next step S3, the edge-emitting semiconductor laser diode 1 is mechanically stable and electrically conductively connected to the photonic integrated circuit 32 by soldering.

[0076] To connect the edge-emitting semiconductor laser diode 1 and the photonic integrated circuit 32 with solder joints 41, the edge-emitting semiconductor laser diode 1 is positioned offset relative to the photonic integrated circuit 32 on solid solder 42 forming the external mounting pad 28 (see FIG. 8 ). The edge-emitting semiconductor laser diode 1 has a y-direction alignment structure 43 and an x-direction alignment structure 44 for lateral alignment of the edge-emitting semiconductor laser diode 1 in a plane parallel to the main surface 9 of the semiconductor layer sequence 2.

[0077] The solid solder 42 is then liquefied into liquid solder 42'. The liquid solder 42' wets the electrical mounting area 27 of the edge-emitting semiconductor laser diode 1, and the volume of the liquid solder 42' redistributes by expanding to cover the entire electrical mounting area 27. The redistribution of the volume of the liquid solder 42' causes the height of the liquid solder 42' to collapse, thereby lowering the edge-emitting semiconductor laser diode 1 (see FIG. 11). The light exit area 11 of the edge-emitting semiconductor laser diode 1 is lowered to align with the light entrance area 40 of the optical integrated circuit 32. After wetting the electrical mounting area 27, the liquid solder 42 has the same diameter as the electrical mounting area 27. During wetting, the liquid solder 42' is guided by the y-direction alignment structure 43 and the x-direction alignment structure 44, and moves the edge-emitting semiconductor laser diode 1 to the correct position through a self-alignment process. The light-exit region 11 of the edge-emitting semiconductor laser diode 1 is aligned with the light-inlet region 40 of the photonic integrated circuit 32. In particular, the light-exit region 11 of the edge-emitting semiconductor laser diode 1 and the light-inlet region 40 of the optical waveguide, which is the active optical element 39 of the photonic integrated circuit 32, coincide with high precision.

[0078] After the liquid solder 42 is applied to the external mounting pad 28, the liquid solder 42 wets the surface of the external mounting pad 28, thereby reducing the thickness of the liquid solder 42. This leads to the lowering of the edge-emitting semiconductor laser diode 1 relative to the optical integrated circuit 32, and in particular, the placement of the z-direction alignment structure 37 within the notch 30 in the electrical insulating layer 20 of the edge-emitting semiconductor laser diode 1 in a self-alignment process.

[0079] After self-alignment of the edge-emitting semiconductor laser diode 1 and the optical integrated circuit 32, the liquid solder 42 solidifies to form a solid solder joint 41 that connects the electrical mounting area 27 and the external mounting pad 28 to each other in a mechanically stable and electrically conductive manner.

[0080] The semiconductor laser devices according to the exemplary embodiments of FIGS. 12 and 13 can be manufactured by the methods already described with reference to FIGS.

[0081] The semiconductor laser device according to the exemplary embodiment of FIGS. 12 and 13 includes an edge-emitting semiconductor laser diode 1 already described with reference to FIGS.

[0082] Furthermore, the semiconductor laser device includes a photonic integrated circuit 32 that is connected to the electrical mounting area 27 of the edge-emitting semiconductor laser diode 1 with the aid of solid-state solder joints 41. Furthermore, the edge-emitting semiconductor laser diode 1 includes an electrical insulation layer 20 having three z-direction alignment structures 37 arranged in the boundary area 31. The z-direction alignment structures 37 are inserted into the cutouts 30 of the electrical insulation layer 20 that are arranged in the boundary area 31.

[0083] Furthermore, the light-exit region 11 of the edge-emitting semiconductor laser diode 1 covers the light-entry region 40 of an optical waveguide that is part of the photonic integrated circuit 32. Electromagnetic laser radiation 6 emitted from the light-exit region 11 of the edge-emitting semiconductor laser diode 1 is coupled into the optical waveguide via the light-entry region 40.

[0084] This application claims priority from German application DE 102022121857.0, the disclosure of which is incorporated herein by reference.

[0085] The invention is not limited to the described embodiments, but rather includes each and every new feature and combination of features, in particular each and every combination of features in the claims, even if that feature or combination itself is not explicitly recited in a claim or embodiment. [Explanation of symbols]

[0086] 1. Edge-emitting semiconductor laser diode 2. Semiconductor Layer Sequence 3 First semiconductor layer 4 Second semiconductor layer 5 Active Area 6 Electromagnetic Laser Radiation 7. Circuit Board 8 Ridge waveguide 9. Main surface of semiconductor layer sequence 10 Facets 11 Light exit area 12 First electrical contact layer 13 Second electrical contact layer 14 Beer 15 First area 16 Second area 17 Electrical Pad Layer 18 First electrical contact pad 19 Second Electrical Contact Pad 20 Electrical insulating layer 21 Distributed Bragg reflector 22 Front of the ridge waveguide 23 Back side of ridge waveguide 24 resonator 25 Optical axis 26 Opening 27 Implementation Area 28 External Mounting Pad 29 Common plane 30 Cutout 31 Boundary area 32 Photonic Integrated Circuits 33 Base Area 34 Edge area 35 Central area 36 Elevation 37 z-direction alignment structure 38 pillars 39 Active Optical Elements 40 Light entrance area 41 Solder joints 42 Solid Solder 42' Liquid Solder 43 y-direction alignment structure 44 x-direction alignment structure 45 Growth direction 46 Longitudinal 47 Insulating layer 48 Feedthrough 49 Photonic Integrated Circuit Main Surface S1 Method steps S2 Method steps S3 Method Steps

Claims

1. An edge-emitting semiconductor laser diode (1), a semiconductor layer sequence (2) having a first semiconductor layer (3) having a first conductivity type and a second semiconductor layer (4) having a second conductivity type, and an active area (5) configured to generate electromagnetic laser radiation (6) during operation, the active area (5) being disposed between the first semiconductor layer (3) and the second semiconductor layer (4); a ridge waveguide (8) provided on a major surface (9) of said semiconductor layer sequence (2); a first electrical contact layer (12) arranged on the main surface (9) of the semiconductor layer sequence (2), the first electrical contact layer (12) being in electrical contact with the first semiconductor layer (3); a second electrical contact layer (13) disposed on the ridge waveguide (8), the second electrical contact layer (13) being in electrical contact with the second semiconductor layer (4); the first electrical contact layer (12) is disposed on the second electrical contact layer (13), so that electrical mounting areas (27) of the edge-emitting semiconductor laser diode (1) are disposed in a common plane (29); an electrical insulating layer (20) electrically insulating a portion of the first electrical contact layer (12) that is in electrical contact with the first semiconductor layer (3) from a portion of the first electrical contact layer (12) disposed on the second electrical contact layer (13); the electrically insulating layer (20) has at least two openings (26); The edge-emitting semiconductor laser diode (1) has the first electrical contact layer (12) and the electrical pad layer (17) disposed in the opening (26) in direct contact therewith.

2. 2. The edge-emitting semiconductor laser diode (1) of claim 1, wherein the electrically insulating layer (20) is a distributed Bragg reflector (21).

3. the ridge waveguide (8) is partially disposed within at least one opening (26) in the electrically insulating layer (20); 2. The edge-emitting semiconductor laser diode (1) of claim 1, wherein the electrically insulating layer (20) exceeds the ridge waveguide (8) in the vertical direction (45).

4. 2. The edge-emitting semiconductor laser diode (1) of claim 1, wherein the ridge waveguide (8) is covered by the first electrical contact layer (12), the second electrical contact layer (13), and an electrical pad layer (17) within at least one opening (26) of the electrical insulating layer (20).

5. the semiconductor layer sequence (2) has a via (14) penetrating the semiconductor layer sequence (2) from the main surface (9); 2. The edge-emitting semiconductor laser diode (1) of claim 1, wherein the first electrical contact layer (12) is in direct physical contact with the first semiconductor layer (3) and / or the substrate (7) at the via (14).

6. the via (14) runs parallel to the ridge waveguide (8); 6. The edge-emitting semiconductor laser diode (1) according to claim 5, wherein the via (14) divides the semiconductor layer sequence (2) into a first region (15) and a second region (16) in a plan view of the main surface (9) of the semiconductor layer sequence (2).

7. the electrical pad layer (17) is at least partially constituted by at least one first electrical contact pad (18) and at least one second electrical contact pad (19); 7. The edge-emitting semiconductor laser diode (1) according to claim 6, wherein the first electrical contact pad (18) is arranged in the first region (15) and the second electrical contact pad (19) is arranged in the second region (16).

8. the first electrical contact pad (18) is configured to make external electrical contact with the first semiconductor layer (3); 8. Edge-emitting semiconductor laser diode (1) according to claim 7, wherein the second electrical contact pad (19) is configured to make external electrical contact with the second semiconductor layer (4).

9. 8. The edge-emitting semiconductor laser diode (1) according to claim 7, wherein the first electrical contact pad (18) and / or the second electrical contact pad (19) have a circular shape in plan view on the main surface (9) of the semiconductor layer sequence (2).

10. 8. The edge-emitting semiconductor laser diode (1) according to claim 7, wherein three first electrical contact pads (18) are arranged in the first region (15) of the semiconductor layer sequence (2) and three second electrical contact pads (19) are arranged in the second region (16) of the semiconductor layer sequence (2).

11. an electrically insulating layer (20) is disposed at least in part on the semiconductor layer sequence (2); the electrically insulating layer (20) has at least one notch (30) in a boundary region (31); 2. The edge-emitting semiconductor laser diode (1) according to claim 1, wherein the main surface (9) of the semiconductor layer sequence (2) is freely accessible at the recess (30).

12. Providing an edge-emitting semiconductor laser diode (1) according to any one of claims 1 to 11; Providing a photonic integrated circuit (32) having at least two external mounting pads (28); and connecting the edge-emitting semiconductor laser diode (1) to the photonic integrated circuit (32), A method for manufacturing a semiconductor laser device, wherein the electrical mounting area (27) of the edge-emitting semiconductor laser diode (1) is mechanically stable and electrically conductively connected to the external mounting pad (28).

13. an electrically insulating layer (20) disposed at least in part on or over the semiconductor layer sequence (2); the electrically insulating layer (20) has at least one notch (30) in a boundary region (31); 13. The method of claim 12, wherein the photonic integrated circuit (32) has at least one z-alignment structure (37) inserted into the notch (30) during a step of connecting the electrical mounting area (27) of the edge-emitting semiconductor laser diode (1) with the external mounting pad (28).

14. The step of connecting the electrical mounting area (27) of the edge-emitting semiconductor laser diode (1) to the external mounting pad (28) comprises: disposing a solid solder (42) on the photonic integrated circuit (32), the solid solder (42) at least partially forming the external mounting pad (28); disposing the electrical mounting area (27) of the edge-emitting semiconductor laser diode (1) on the solid solder (42) in an offset manner; and liquefying the solid solder (42) into a liquid solder (42'); 13. The method of claim 12, wherein the liquid solder (42') moves the edge-emitting semiconductor laser diode (1) so that a light exit area (11) of the edge-emitting semiconductor laser diode (1) is self-aligned with an active optical element (39) of the photonic integrated circuit (32).

15. An edge-emitting semiconductor laser diode (1) according to any one of claims 1 to 11, which emits electromagnetic laser radiation (6) from a light exit area (11) during operation; a photonic integrated circuit (32) having an active optical element (39), the active optical element (39) being aligned with the light exit area (11); an electrically insulating layer (20) is disposed at least in part on the semiconductor layer sequence (2); the electrically insulating layer (20) has at least one notch (30) in a boundary region (31); The semiconductor laser device, wherein the photonic integrated circuit (32) has at least one z-alignment structure (37) inserted into the notch (30).

16. 16. The semiconductor laser device of claim 15, wherein the z-alignment structure (37) is a post (38) extending from a major surface of the photonic integrated circuit (32) at the cutout (30).

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