Method for manufacturing semiconductor laser and semiconductor laser

Abstract

The invention relates to a method for producing at least one semiconductor laser. The method comprises: providing a semiconductor layer sequence having at least one ridge waveguide and a widened region, wherein a main extension direction of the widened region extends transversely or perpendicularly to a main extension direction of the ridge waveguide; and at least one main structure of the semiconductor laser consisting of the widened region, wherein the main structure is connected to the ridge waveguide and comprises a coupling-out facet of the semiconductor laser. According to the invention, the main structure is designed in a stepped manner and / or at least one auxiliary structure is formed from a widened region, said auxiliary structure being laterally spaced apart from the main structure. The invention further relates to a semiconductor laser.

Description

[0001] A method for manufacturing a semiconductor laser and a semiconductor laser are proposed.

[0002] The facets of a semiconductor laser can be created, for example, by breaking the semiconductor layer sequence and thus separating the semiconductor lasers in a semiconductor laser array. Alternatively, the facets of the semiconductor laser can also be created by etching before separation. Here, for example, depending on the semiconductor layer sequence or the atomic concentration in the semiconductor layer sequence, etched portions can be created in the active region of the semiconductor layer sequence.

[0003] The objective is to propose a method for manufacturing semiconductor lasers that enables efficient production. Another objective is to propose an improved semiconductor laser.

[0004] This objective is achieved through the subject matter of the independent claims. Advantageous design options and improvements are given in the dependent claims.

[0005] According to at least one embodiment, a method of manufacturing at least one semiconductor laser includes providing a sequence of semiconductor layers.

[0006] The semiconductor layer sequence can have a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type. For example, the first semiconductor layer is p-doped and the second semiconductor layer is n-doped, or vice versa.

[0007] An active region may be disposed between the first semiconductor layer and the second semiconductor layer. The active region may be configured to generate electromagnetic radiation, such as radiation in the ultraviolet, visible, or infrared spectral range. The active region may, for example, have a pn junction, a quantum well structure, and / or a multiple quantum well structure. For example, the semiconductor layer sequence may include III-V group semiconductor materials (e.g., GaN or AlInGaN) or II-VI group semiconductor materials.

[0008] The semiconductor layer sequence can have a stacking orientation. For example, the first semiconductor layer, the active region, and the second semiconductor layer are arranged sequentially along the stacking orientation, such as directly in sequence.

[0009] The semiconductor layer sequence, for example, has a main extension plane. The stacking direction of the semiconductor layer sequence may extend perpendicularly to or approximately perpendicular to the main extension plane of the semiconductor layer sequence.

[0010] The semiconductor layer sequence can be provided on a support. For example, providing the semiconductor layer sequence includes sequentially growing the semiconductor layers of the semiconductor layer sequence onto a growth substrate. The support can be a growth substrate. Alternatively, the support can be, for example, a support different from the growth substrate.

[0011] According to at least one embodiment of a method for manufacturing at least one semiconductor laser, the semiconductor layer sequence has at least one ridge waveguide.

[0012] At least one ridge waveguide may be formed at least partially from a sequence of semiconductor layers. The at least one ridge waveguide (hereinafter also referred to as a ridge waveguide) may be a vertical protrusion of the semiconductor layer sequence. The vertical direction extends, for example, parallel to the stacking direction of the semiconductor layer sequence. In other words, the semiconductor layer sequence may have a protrusion, such as a locally defined protrusion, which may be a ridge waveguide. The protrusion may, for example, be arranged on the side of the semiconductor layer sequence opposite to the carrier.

[0013] The ridge waveguide may have a main extension direction. The main extension direction of the ridge waveguide extends, for example, at least partially parallel or approximately parallel to the main extension plane of the semiconductor layer sequence. For example, the ridge waveguide is configured to be elongated, particularly ridge-shaped. In a top view of the semiconductor layer sequence, the ridge waveguide is, for example, at least approximately rectangular.

[0014] A semiconductor layer sequence may have more than one ridge waveguide. For example, a semiconductor layer sequence may have at least two ridge waveguides. The two ridge waveguides may be laterally spaced apart from each other. For example, the at least two ridge waveguides may extend parallel or approximately parallel to each other. In other words, the main extension direction of the ridge waveguide may extend at least partially parallel or approximately parallel to the main extension direction of the other ridge waveguide. For example, a semiconductor layer sequence may include multiple ridge waveguides, such as a ridge waveguide and multiple other ridge waveguides. The additional ridge waveguides may have the same characteristics as the ridge waveguide or at least one ridge waveguide.

[0015] The lateral direction is understood as the direction that extends parallel to the main extension plane of the semiconductor layer sequence. The vertical direction is generally understood as the direction that extends perpendicular to the main extension plane of the semiconductor layer sequence. The vertical and lateral directions are transverse to each other, for example, orthogonal to each other.

[0016] According to at least one embodiment of a method for manufacturing at least one semiconductor laser, a sequence of semiconductor layers has a widened region. The widened region may have a configuration, such as a layer stack, that fully or at least approximately corresponds to the configuration of a ridge waveguide. For example, the widened region is a region of the ridge waveguide in which the ridge waveguide has a larger extension in a direction transverse to or perpendicular to the main extension direction of the ridge waveguide compared to a region of the ridge waveguide outside the widened region. The extension of the ridge waveguide outside the widened region is, for example, the width of the ridge waveguide. The ridge waveguide may be integrally formed with the widened region. For example, at least two ridge waveguides may have widened regions. The widened regions of the ridge waveguides may, for example, be connected to or spaced apart from each other. For example, the semiconductor layer sequence includes continuously formed widened regions, particularly only continuously formed widened regions.

[0017] According to at least one embodiment of the method of manufacturing at least one semiconductor laser, the main extension direction of the widened region extends laterally or perpendicularly to the main extension direction of the ridge waveguide. The main extension direction of the ridge waveguide may, for example, be the direction in which the ridge waveguide has its maximum extension. For example, the main extension direction of the ridge waveguide extends parallel or nearly parallel to the resonator of the semiconductor laser. The resonator of the semiconductor laser is, for example, arranged between two resonator surfaces. For example, one of the resonator surfaces has a coupling output facet of the semiconductor laser. The main extension direction of the widened region may extend laterally or perpendicularly to the main extension direction of the ridge waveguide. For example, the widened region may intersect with at least one ridge waveguide.

[0018] According to at least one embodiment, a method of manufacturing at least one semiconductor laser includes forming at least one main structure of the semiconductor laser by a widened region. The at least one main structure can therefore be formed from the material of the widened region. The at least one main structure can be formed, for example, by structuring the widened region. For example, when structuring the widened region, a groove is formed in the widened region. For example, when forming the groove, sidewalls / multiple sidewalls of the main structure are formed and / or define the main structure. Multiple sidewalls of the main structure may also be referred to hereinafter as sidewalls of the main structure. The sidewalls of the main structure may include all surfaces of the main structure that extend perpendicularly to or at least approximately perpendicular to the main extension plane of the semiconductor layer sequence. The sidewalls of the main structure may, for example, be directly adjacent to the groove and at least partially laterally define the groove.

[0019] Alternatively, more than one groove may be constructed. The grooves are arranged, for example, spaced apart from each other. In particular, each groove may be arranged between the first sub-region and the second sub-region of the ridge waveguide.

[0020] The groove is configured, for example, such that it extends partially through a sequence of semiconductor layers. For example, the groove also extends into the carrier. The groove can, for example, divide a ridge waveguide into a first sub-region and a second sub-region of the ridge waveguide. In other words, the groove can be arranged between the first and second sub-regions of the ridge waveguide. The groove can, for example, be created by dry chemical etching in the widened region. Therefore, the sides of the main structure can have etching marks.

[0021] The groove may terminate flush with the widening region in a direction parallel to the main extension direction of the ridge waveguide. Alternatively, the groove may extend at least partially beyond the widening region in this direction, for example, by at least 1 µm, or at least 5 µm. The groove may extend beyond the widening region by a maximum of 50 µm, for example, a maximum of 30 µm or a maximum of 10 µm. It is also feasible for the groove to be completely disposed within the widening region in the lateral direction. The width of the widening region surrounding the edge of the groove may be from 0.1 µm to 5 µm, including the endpoint values, for example, from 0.2 µm to 3 µm, including the endpoint values.

[0022] The side of the main structure facing away from the groove is, for example, at least partially adjacent to the ridge waveguide. It is feasible for the side of the main structure facing away from the groove to be directly adjacent to the ridge waveguide. For example, the main structure extends the ridge waveguide. The main structure is, for example, arranged in the optical active region of the semiconductor laser. Compared to the optical passive region of the semiconductor laser, the optical active region of the semiconductor laser can be the region where electromagnetic radiation is coupled out during operation.

[0023] Therefore, the main structure can be, for example, a structured region of the widened region that is directly adjacent to the ridge waveguide. The main structure can be implemented as part of the widened region and / or part of the ridge waveguide. The sides of the main structure extend at least partially in the transverse direction by bending or folding. The main structure can extend beyond the groove along the main extension direction of the ridge waveguide. In other words, the main structure can be configured, for example, as a protrusion made of the widened region. The protrusion, for example, extends into the groove by a length of 1µm to 60µm, including the endpoint value, for example, 5µm to 30µm, including the endpoint value. For example, the sides of the main structure extend at least partially transversely to or perpendicular to the main extension direction of the widened region.

[0024] According to at least one embodiment of a method for manufacturing at least one semiconductor laser, the main structure is connected to a ridge waveguide. For example, the main structure may be adjacent to the ridge waveguide, particularly directly adjacent. Alternatively or additionally, the main structure may be integrally formed with the ridge waveguide.

[0025] The ridge waveguide can transition into the main structure. This can mean that the main structure is arranged at least partially along the main extension direction of the ridge waveguide. For example, the main structure directly follows the ridge waveguide along its main extension direction. The edge of the widened region can be arranged between the ridge waveguide and the main structure. For example, the main structure forms a resonator. In particular, the resonator length of the semiconductor laser can be defined by the main structure. For example, the resonator length is derived from the length of the ridge waveguide along its main extension direction and the extension of the main structure along its main extension direction. For example, the length of the ridge waveguide along its main extension direction can be from 100µm to 1500µm. For example, the main structure can extend the length of the ridge waveguide along its main extension direction by 60µm to define the resonator length of the semiconductor laser.

[0026] According to at least one embodiment of a method for manufacturing at least one semiconductor laser, the main structure includes a coupling output facet of the semiconductor laser. A region on the side of the main structure, such as a region extending perpendicularly or nearly perpendicularly to the main extension direction of the ridge waveguide, has, for example, a resonator facet or a coupling output facet. The coupling output facet of the semiconductor laser may have a crystalline plane extending perpendicularly or nearly perpendicularly to the main extension direction of the ridge waveguide. The coupling output facet is, for example, the side of the main structure facing away from the ridge waveguide. The side of the main structure may be at least partially formed by the resonator facet and / or the coupling output facet. The coupling output facet is, for example, the surface from which electromagnetic radiation is coupled out of the semiconductor laser during operation.

[0027] According to at least one embodiment of the method for manufacturing at least one semiconductor laser, the main structure is implemented in a stepped shape. The main structure may include, for example, two steps, or at least two steps. The main structure may also include at least three steps or more steps.

[0028] The steps of the main structure are arranged, for example, along the main extension direction of the ridge waveguide. The first step can be arranged closest to the ridge waveguide. Therefore, the first step is arranged, for example, between the ridge waveguide and another step along the main extension direction of the ridge waveguide. For example, the other step is arranged between the coupling output facet of the main structure and the first step. Alternatively or additionally, the other step may have a coupling output facet.

[0029] The step may be characterized, for example, by having different extensions along a direction perpendicular or approximately perpendicular to the main extension direction of the ridge waveguide. Alternatively or additionally, the step may extend beyond another step in a transverse direction parallel to the main extension direction of the widened region, and vice versa. In other words, the stepped main structure may have a shoulder and / or multiple angle and orientation variations in a top view.

[0030] According to at least one embodiment of a method for manufacturing at least one semiconductor laser, at least one auxiliary structure is formed by a widened region. For example, the auxiliary structure is laterally spaced from the main structure.

[0031] The fact that at least one auxiliary structure is formed by a widened region can mean that at least one auxiliary structure is composed of the material of the widened region. Therefore, the auxiliary structure can be implemented as part of the widened region. For example, the auxiliary structure is not implemented as part of the ridge waveguide and is spaced apart from the ridge waveguide. In particular, the auxiliary structure is located on the side of the ridge waveguide. In other words, the ridge waveguide does not transition into the auxiliary structure. For example, the auxiliary structure does not have a side that couples the electromagnetic radiation generated by the semiconductor laser during operation. At least one auxiliary structure can, for example, be constructed using the same process as the main structure and / or in a common process with the main structure. In other words, all features disclosed for constituting the main structure can be used to constitut the auxiliary structure, and vice versa.

[0032] For example, when creating the groove, the sidewalls of the auxiliary structure are formed. The groove can be created by dry chemical etching. The sidewalls of the auxiliary structure can at least partially define the groove laterally. The sidewalls of the auxiliary structure can include all surfaces of the auxiliary structure that extend perpendicular to or at least approximately perpendicular to the main extension plane of the semiconductor layer sequence. For example, two sub-regions of the sidewalls of the auxiliary structure can form an angle different from 180°. In other words, the sidewalls of the auxiliary structure, for example in a top view of the semiconductor layer sequence, can extend at least partially laterally and / or perpendicular to the main extension direction of the widened region and / or extend in a partially curved and / or bent manner. In the top view, the auxiliary structure can have a convex structure and / or a concave structure. In particular, the sidewalls of the auxiliary structure can extend at least partially convex or concave. In other words, the auxiliary structure can, for example, be configured as a protrusion made of the widened region. The length of the auxiliary structure protruding into the groove, for example, is 0.5µm to 60µm, including the endpoint values, for example, 5µm to 30µm, including the endpoint values.

[0033] Auxiliary structures can be arranged spaced apart from the main structures. For example, auxiliary structures are arranged in the optically passive region of a semiconductor laser. The optically passive region can be a region of the semiconductor laser that does not generate or couple output electromagnetic radiation during operation. It is feasible for the auxiliary structures not to have the resonator surface and / or coupling output facet of the semiconductor laser. In particular, electromagnetic radiation generated in the active region of the semiconductor laser is not coupled at the auxiliary structure. The auxiliary structure, for example, is not directly adjacent to the ridge waveguide. In particular, the auxiliary structure can be arranged such that the auxiliary structure does not follow the ridge waveguide along its main extension direction. For example, the semiconductor layer sequence includes two ridge waveguides having a main structure arranged thereon. At least one auxiliary structure, for example, at least two auxiliary structures, can be arranged between the two main structures. Therefore, the widened region can have at least two protrusions between the two main structures.

[0034] In at least one embodiment of the method of manufacturing at least one semiconductor laser, a sequence of semiconductor layers is provided having at least one ridge waveguide and a broadened region, wherein the main extension direction of the broadened region extends laterally or perpendicularly to the main extension direction of the ridge waveguide. The broadened region constitutes at least one main structure of the semiconductor laser, wherein the main structure is connected to the ridge waveguide and includes a coupling output facet of the semiconductor laser. The main structure is implemented as a stepped shape, and / or the broadened region constitutes at least one auxiliary structure, which is laterally spaced from the main structure.

[0035] The method for manufacturing at least one semiconductor laser described herein allows for the efficient fabrication of semiconductor lasers. Furthermore, at least one semiconductor laser can be manufactured at low cost. Specifically, the resonator facets and / or coupling output facets of the semiconductor laser can be fabricated by etching. By constructing a stepped main structure or auxiliary structures laterally spaced from the main structure, the etching of the coupling output facets during wet chemical etching—either on the crystalline plane used to expose the coupling output facets or on the sides of the main and / or auxiliary structures—can be minimized, reduced, or prevented. This allows for the efficient fabrication of high-quality resonator facets or coupling output facets. Therefore, wet chemical etching can be specifically influenced by the shape of the grooves or the shape of the main and / or auxiliary structures to obtain particularly smooth resonator facets through etching. Furthermore, multiple resonator facets can be fabricated simultaneously and with minimal loss.

[0036] According to at least one embodiment of the method for manufacturing a semiconductor laser, the coupling output facet of the semiconductor laser is produced by wet chemical etching.

[0037] Wet chemical etching allows for the removal of material not only in the vertical direction but also in the lateral direction. The material can be layers of a semiconductor layer sequence. In wet chemical etching, for example, the material of the semiconductor layer sequence can be etched in the lateral direction. For example, the sides of the main structure are smoothed during wet chemical etching. The average roughness of the sides of the main structure after wet chemical etching is, for example, a maximum of 50 nm, a maximum of 30 nm, or a maximum of 10 nm. Specifically, the RMS roughness (root mean square roughness) is, for example, a maximum of 10 nm, a maximum of 2 nm, or a maximum of 1 nm. The sides of the main structure, through wet chemical etching, can, for example, form the resonator surface and / or coupling output facets of a semiconductor laser. The sides of the main structure can partially, particularly only partially, have crystalline planes that extend perpendicularly to or nearly perpendicular to the main extension direction of the ridge waveguide. Crystalline planes extending perpendicularly to the main extension direction of the ridge waveguide are exposed, for example, at the sides of the main structure by wet chemical etching. The coupling output facets can, for example, have etching marks.

[0038] Therefore, the coupling output facets can be etched before the semiconductor laser array is separated into individual semiconductor lasers. In particular, the coupling output facets are not generated during separation (e.g., by fracture).

[0039] According to at least one embodiment, at least one auxiliary structure is configured as a trapezoid or semicircle in a top view of the semiconductor layer sequence.

[0040] The auxiliary structure can thus have at least two crystalline planes. For example, the side of the auxiliary structure facing the groove has at least one directional change. At the directional change, the side of the auxiliary structure can extend in a curved and / or bent manner. The auxiliary structure can be configured as a semicircle in a top view, for example. The auxiliary structure thus has, for example, multiple directional changes. Alternatively, the auxiliary structure can be configured as a stepped shape and has, for example, a trapezoidal or semicircular outline in a top view. It is feasible for all sides of the auxiliary structure to have etched marks. For example, in a finished semiconductor laser, all exposed sides of the auxiliary structure can have etched marks.

[0041] By varying the direction of the process, drilling or etching can be reduced or prevented when creating resonator surfaces (e.g., coupling output facets) through wet chemical etching.

[0042] Alternatively or additionally, the main structure may be configured as a trapezoid or semicircle in the top view.

[0043] According to at least one embodiment of a method for manufacturing a semiconductor laser, a sequence of semiconductor layers includes at least two ridge waveguides, wherein at least two main structures are formed in a broadened region, and at least two auxiliary structures are formed in the broadened region, wherein the at least two auxiliary structures are arranged between the main structures and adjacent additional main structures. The at least two main structures are formed, for example, at at least two ridge waveguides. Specifically, a main structure may be formed at each ridge waveguide. Alternatively or additionally, at least one main structure may be formed at each subsequent region of the ridge waveguide where the semiconductor laser is formed. The adjacency of two main structures may, in particular, mean that no additional main structure is arranged between them. However, at least one or more auxiliary structures may be arranged between two adjacent main structures.

[0044] By constructing at least two auxiliary structures, the groove can have a structured portion in the widened region, through which a high-quality resonator surface, such as the coupling output surface of a semiconductor laser, can be manufactured by means of wet chemical etching.

[0045] According to at least one embodiment of a method for manufacturing a semiconductor laser, a main structure and at least one auxiliary structure are constructed in a common etching process.

[0046] The main and auxiliary structures of a semiconductor laser can be formed using a dry chemical etching process (e.g., plasma etching). For example, dry chemical etching removes regions of the widened area that do not form the main or auxiliary structures of the semiconductor laser.

[0047] In other words, the broadened region can be structured using dry chemical etching, wherein the regions of the broadened region that form at least one main structure and at least one auxiliary structure are preserved. Specifically, when creating the groove, the regions of the broadened region that form at least one main structure and at least one auxiliary structure are not removed.

[0048] For example, the main structure and auxiliary structure are formed before the resonator surface is wet-etched chemically. However, it is also feasible to generate the main structure and auxiliary structure sequentially by dry-etching chemically.

[0049] For example, the sides of the main structure and auxiliary structure are smoothed in a common wet chemical etching process. During wet chemical etching, spontaneous etching is possible depending on the structure or configuration of the semiconductor layer sequence and / or due to the atomic concentration within the semiconductor layer sequence. Etching can occur, for example, in active regions.

[0050] By constructing the main and auxiliary structures prior to wet chemical etching, etching can be prevented or at least reduced. This is achieved, for example, by the presence of multiple distinct crystal planes at the auxiliary and / or main structures. For instance, lateral diffusion of the etched portion is slowed at convex and / or concave structures. The auxiliary structures can, for example, influence the etching behavior at the coupled output facets during wet chemical etching. By avoiding etching, facet quality, such as the quality of the coupled output facets, can be improved.

[0051] According to at least one embodiment, the main structure has at least partially a crystalline plane extending perpendicular to the main extension direction of the ridge waveguide, the crystalline plane forming a coupling output facet. At the crystalline plane extending perpendicular to the main extension direction of the ridge waveguide, electromagnetic radiation generated by the active region can be effectively coupled out from the semiconductor laser.

[0052] According to at least one embodiment, the main structure has at least two steps along the main extension direction of the ridge waveguide. The sides of the main structure may extend convexly and / or concavely, particularly curved or bent, in the regions of the two steps and / or in the transition from the first step to the other step. This prevents etching during wet chemical etching.

[0053] According to at least one embodiment of the method of manufacturing a semiconductor laser, the first step closest to the ridge waveguide arrangement has a lateral extension smaller than the extension of the additional step located between the first step and the coupling output facet.

[0054] For example, the first step has a lateral extension smaller than the width of the ridge waveguide. The main structure can then have an undercut in the top view of the resonator surface.

[0055] By creating undercuts, for example, different crystal planes and / or multiple directional variations are formed. This can have a positive impact on the quality of the resonator surface of a semiconductor laser during wet chemical etching, because the etching is slowed down by multiple directional variations or convex and / or concave structures of the main structure.

[0056] According to at least one embodiment of the method for manufacturing a semiconductor laser, the widened region is structured in the lateral direction before forming at least one main structure and / or at least one auxiliary structure. The structured portion, for example, has at least one transition portion where the sides of the widened region extend in a curved and / or bent manner.

[0057] For example, the widened region has at least one notch extending in a direction away from the coupling output facet of the subsequently constructed semiconductor laser. The widened region may have multiple notches. For example, the sides of the widened region are configured to be at least approximately wavy. The notch may be trapezoidal or semi-circular in a top view, for example. The notch extends away from the coupling output facet of the semiconductor laser by, for example, at least 2 µm, or at least 5 µm. For example, the notch extends beyond the coupling output facet by at most 50 µm, or at least 30 µm.

[0058] According to at least one embodiment of the method for manufacturing a semiconductor laser, a groove is formed in the widened region such that the structure of the groove follows the structured portion of the widened region. The main structure is, for example, configured as a convex shape. Alternatively, it is feasible for the main structure to consist only of a flat region of the widened region in the lateral direction. The auxiliary structure is, for example, configured as a convex or concave shape.

[0059] Another concept in this implementation is to increase the edge length of the sides of the main structure and / or auxiliary structure. Furthermore, different crystal axes can be constructed.

[0060] According to at least one embodiment of a method for manufacturing a semiconductor laser, multiple semiconductor lasers are manufactured in a common process. The multiple semiconductor lasers may be separated into multiple emitters and / or single emitters.

[0061] For example, a semiconductor laser array can be separated into semiconductor lasers. A semiconductor laser may, for example, comprise only a ridge waveguide or a region of a ridge waveguide. Alternatively, the semiconductor laser array can be separated into at least one multi-emitter. The completed semiconductor laser may comprise more than one ridge waveguide. A main structure with a coupling output facet can be arranged at each ridge waveguide. At least one or more auxiliary structures can be arranged between the main structures. For example, the semiconductor laser array can be separated or split along a groove in a direction parallel to the main extension direction of the widened region. It is further feasible to separate the semiconductor laser array parallel to the main extension direction of the ridge waveguide. The semiconductor laser array can be cut or separated, for example, approximately in the middle, between two adjacent ridge waveguides.

[0062] According to at least one embodiment of a method for manufacturing a semiconductor laser, at least one auxiliary structure is laterally formed between a main structure and another main structure in a widened region. This at least one auxiliary structure allows the lateral etching to be moved away from the facet. This enables the efficient fabrication of a semiconductor laser with an etch-coupled output facet.

[0063] According to at least one embodiment of the method for manufacturing a semiconductor laser, at least one auxiliary structure is completely retained in the separate semiconductor laser. If only one auxiliary structure is arranged between the main structure and another main structure, then when the main structures are separated, alternatively only approximately half of the auxiliary structure can be retained in the separate semiconductor laser.

[0064] Furthermore, a semiconductor laser is proposed. The semiconductor laser can be manufactured, for example, by the methods described herein. In other words, all the features disclosed in the methods for manufacturing a semiconductor laser can be used in a semiconductor laser, and vice versa.

[0065] According to at least one embodiment of a semiconductor laser, the semiconductor laser includes a sequence of semiconductor layers having a ridge waveguide and a broadened region. The main extension direction of the broadened region extends laterally or perpendicularly to the main extension direction of the ridge waveguide. The semiconductor layer sequence has a main structure connected to the ridge waveguide, wherein the main structure includes a coupling output facet of the semiconductor laser and is formed by the broadened region. The main structure is implemented as a stepped shape. Alternatively or additionally, the semiconductor layer sequence has an auxiliary structure formed by the broadened region and laterally spaced from the main structure.

[0066] The semiconductor laser described herein can have a coupled output facet manufactured by etching. The coupled output facet can be manufactured efficiently, at low cost, and with high quality. The efficiency and function of the semiconductor laser can thus be improved.

[0067] According to at least one embodiment of the semiconductor laser, the main structure and / or auxiliary structure have at least one side. At least one side extends, for example, at least partially laterally and / or perpendicularly to the main extension direction of the widened region.

[0068] According to at least one embodiment of the semiconductor laser, the auxiliary structure is at least approximately trapezoidal, quarter-circular, or semi-circular in a top view of the semiconductor layer sequence.

[0069] According to at least one embodiment of a semiconductor laser, the main structure has at least two steps along the main extension direction of the ridge waveguide.

[0070] According to at least one embodiment of a semiconductor laser, the semiconductor laser is implemented as a multi-emitter having at least two main structures and at least one auxiliary structure, wherein the auxiliary structure is arranged spaced apart from the main structures along the main extension direction of the widened region.

[0071] The method for manufacturing a semiconductor laser described herein and the semiconductor laser described herein will be explained in more detail below with reference to embodiments and accompanying drawings.

[0072] Figure 1A and 1B A comparative example of a semiconductor laser is shown.

[0073] Figures 2 to 7 The steps of a method for manufacturing a semiconductor laser according to an embodiment are illustrated in a schematic top view.

[0074] Figure 8 and 9 A schematic top view illustrates the stepped main structure or auxiliary structure according to an embodiment.

[0075] Figures 10 to 12 A schematic top view illustrates intermediate steps of a method for manufacturing a semiconductor laser according to an embodiment.

[0076] Figures 13 to 15 A schematic top view illustrates intermediate steps of a method for manufacturing a semiconductor laser according to other embodiments.

[0077] Figure 16 A schematic top view illustrates an intermediate step in a method for manufacturing a semiconductor laser according to another embodiment.

[0078] The same, similar, or functionally equivalent elements in the accompanying drawings are given the same reference numerals. The shapes and dimensional proportions of the elements shown in the drawings should not be considered as drawn to scale. Rather, for better display and / or better understanding, individual elements may be exaggerated.

[0079] Figure 1AA diagram of the resonator surface 46 of the semiconductor laser 1 is shown. Here, an etched portion 7 is formed in the active region 21 of the semiconductor layer sequence 2. The etched portion 7 can be generated during a wet chemical etching process. Therefore, the resonator surface 46 can be partially etched. The resonator surface 46 of the semiconductor laser 1 can be, for example, a facet of the semiconductor laser 1, particularly the coupling output facet 41 of the semiconductor laser 1.

[0080] Figure 1B A comparative example of a semiconductor laser 1 with a resonator surface 46 is shown, which has an etched portion 7 in the active region 21 of a semiconductor layer sequence 2. The semiconductor layer sequence 2 has a ridge waveguide 3 and a broadened region 32. The sidewalls 42 of the main structure 4 can be partially etched by the etched portion 7. One concept of the method for manufacturing the semiconductor laser 1 described herein is to minimize, reduce, or prevent Figure 1A Or the etched portion 7 shown in 1B.

[0081] Figure 2 A schematic top view of a semiconductor layer sequence 2 in a method of manufacturing a semiconductor laser 1 according to one embodiment is shown. Here and hereinafter, a top view means that the line of sight extends perpendicular to the main extending plane of the semiconductor layer sequence 2. In the method steps shown herein, the semiconductor layer sequence 2 is provided.

[0082] Semiconductor layer sequence 2 has at least one ridge waveguide 3. Semiconductor layer sequence 2 may have at least one additional ridge waveguide 31. For example, semiconductor layer sequence 2 has multiple ridge waveguides 3 and 31. The ridge waveguides 3 and the additional ridge waveguides 31 extend parallel or approximately parallel to each other.

[0083] Semiconductor layer sequence 2 has a broadened region 32. The main extension direction of the broadened region 32 extends laterally or perpendicularly to the main extension direction of the ridge waveguide 3. For example, the broadened region 32 also extends laterally or perpendicularly to the main extension direction of another ridge waveguide 31. The broadened region 32 can be formed continuously, particularly integrally. For example, the broadened regions 32 of ridge waveguides 3 and 31 form a continuous broadened region 32.

[0084] Figure 3 A schematic diagram of another method step in the method of manufacturing semiconductor laser 1 is shown. Figure 3 A semiconductor laser array 10 is shown. Figure 3 The method steps shown are, for example, followed by... Figure 2 The method steps are shown. Here, at least one main structure 4 of the semiconductor laser 1 is formed by the widened region 32. The main structure 4 is connected to the ridge waveguide 3. The main structure 4 includes the resonator surface 46 of the semiconductor laser 1. The resonator surface 46 is, for example, the coupling output surface 41 of the semiconductor laser 1.

[0085] At least one auxiliary structure 5 can be formed from the widened region 32. The at least one auxiliary structure 5 can be formed during the construction of the main structure 4. Then, the at least one auxiliary structure 5 is laterally spaced from the at least one main structure 4. For example, the auxiliary structure 5 is laterally spaced from all the main structures 4, 45 formed by the widened region 32. The auxiliary structure 5 is arranged between two adjacent main structures 4, 45.

[0086] Figure 4 A step of a method for manufacturing a semiconductor laser 1 according to one embodiment is shown in a schematic top view. Figure 4 The method steps shown represent the completed semiconductor laser array 10, which can be separated into semiconductor laser 1, single emitter 12, and / or multiple emitter 11 in subsequent method steps (see [link]). Figure 6 ).

[0087] In the embodiment shown here, at least one main structure 4 and at least one auxiliary structure 5 of the semiconductor laser 1 are configured as trapezoidal. Alternatively or additionally, the main structures 4, 45 may be convex and / or concave, for example, stepped and / or circular, in a top view. For example, at least one main structure 4, 45 may be configured as trapezoidal, at least one main structure 4, 45 may be configured as circular, and / or at least one main structure 4, 45 may be configured as stepped. All the main structures 4, 45 of the semiconductor laser array 10 may have the same or approximately the same shape, or at least partially different shapes from each other. The main structure 4 has a side 42.

[0088] Auxiliary structure 5 is arranged between two adjacent main structures 4 and 45. The auxiliary structure has a side 51. Another auxiliary structure 52 is arranged between two adjacent main structures 4 and 45. Another auxiliary structure 52 is arranged between auxiliary structure 5 and another main structure 45.

[0089] For example, the lateral dimension d2 of the auxiliary structure 5 can be less than or equal to the lateral dimension d1 of the main structures 4 and 45. For example, the lateral dimensions of the main structures 4 and 45 and the auxiliary structure 5 can all be greater than 1µm. Furthermore, the lateral dimensions of the main structures 4 and 45 and the auxiliary structure 5 can all be less than 100µm.

[0090] For example, the main structures 4, 45 and / or auxiliary structures 5, 52 are formed or defined in the widened region by forming a groove 6 through dry chemical etching. The groove 6 may extend vertically through the semiconductor layer sequence 2. For example, the groove 6 may extend vertically completely through the semiconductor layer sequence 2, for example, into a substrate not shown.

[0091] The groove 6 is configured as a continuous groove, for example, in the transverse direction. In other words, the groove 6 in the widened region 32 is continuously configured and extends completely or almost completely along the extension of the widened region 32 in the transverse direction. For example, the extension of the groove 6 along the main extension direction of the widened region 32 at least approximately corresponds to the extension of the widened region 32 along the main extension direction of the widened region 32. Here, "at least approximately" can mean that the groove 6 and the extension of the widened region 32 along the main extension direction of the widened region 32 are equal. Alternatively, the extension of the groove 6 along the main extension direction of the widened region 32 can be smaller.

[0092] The groove 6 extends entirely across the width of the ridge waveguide 3. The width of the ridge waveguide 3 is the extension of the ridge waveguide 3 perpendicular to its main extension direction. The groove 6 is arranged between the first sub-region 35 and the other sub-region 36 of the ridge waveguide 3. The sub-regions 35 and 36 of the ridge waveguide 3 can be assigned to different semiconductor lasers 1 after the semiconductor laser array 10 is separated.

[0093] In the widened region 32, the main structure 4 is arranged in the first sub-region 35 of the ridge waveguide 3 and in another sub-region 36 of the ridge waveguide 3.

[0094] The main structure 4 and the auxiliary structure 5 are formed, for example, in a common etching process. The coupling output facet of the semiconductor laser 1 is produced, for example, by wet chemical etching.

[0095] Figure 5 A semiconductor laser array 10 according to another embodiment is shown.

[0096] Figure 5 Semiconductor laser array 10 and Figure 4 The difference in the semiconductor laser array 10 shown is that only the auxiliary structure 5 is arranged between two adjacent main structures 4 and 45.

[0097] Figure 6 A semiconductor laser array 10 according to another embodiment is shown.

[0098] Figure 6 Semiconductor laser array 10 and Figure 4 The difference in the semiconductor laser array 10 shown is that the auxiliary structure 5 and two additional auxiliary structures 52 are arranged between the main structure 4 and the additional main structure 45. Figures 4 to 6In some embodiments, the distance between the main structure 4 and another main structure 45 can be at least approximately equal. Therefore, the extension of the groove 6 between the main structure 4 and the auxiliary structure 5, or the extension of the auxiliary structure 5 along the main extension direction of the widened region 32, can be different from each other. Furthermore, in this and other embodiments, the main structures 4, 45 and the auxiliary structures 5, 52 can have different extensions, shapes, and distances from each other.

[0099] Multiple semiconductor lasers 1 in the semiconductor laser array 10 can be fabricated in a common process. Subsequently, the semiconductor laser array 10 can be separated into multiple emitters 11 and / or single emitters 12. For example, the semiconductor laser array can be separated along separation lines L1 and L2. At least one auxiliary structure 5 can be completely retained within the separated semiconductor lasers 1.

[0100] Figure 7 A semiconductor laser array 10 according to another embodiment is shown. The semiconductor laser array 10 includes a ridge waveguide 3 having a first sub-region 35 and another sub-region 36, and another ridge waveguide 31. The other ridge waveguide 31 also has a first sub-region and a second sub-region. The first sub-region 35 and the other sub-region 36 are spaced apart from each other by grooves 6. A main structure 4 is arranged at the first sub-region 35 of the ridge waveguide 3. The main structure 4 is configured as a stepped structure. The main structure 4 has two steps 43 and 44. In particular, the main structure 4 may have at least two steps 43 and 44. The first step 43 is the step of the main structure 4 closest to the ridge waveguide. The other step 44 is arranged between the coupling output facet 41 of the main structure 4 and the first step 43. Alternatively or additionally, the other step 44 may have the coupling output facet 41.

[0101] Figure 8 A schematic top view of a stepped main structure 4 according to one embodiment is shown. The main structure 4 has a first step 43 and a further step 44. Thus, the embodiment of the main structure 4 shown here has two steps.

[0102] Figure 9 A schematic top view of the stepped main structure 4 according to another embodiment is shown. Figure 8 Compared to the embodiment shown, the main structure 4 shown here includes a first step 43 and two additional steps 44. The additional steps 44 have a coupling output facet 41 of the semiconductor laser 1 on the side opposite to the first step 43.

[0103] Alternatively, Figure 8 and Figure 9 An embodiment of the stepped auxiliary structure 5 can also be shown.

[0104] Figures 10 to 12A schematic top view of a semiconductor laser array 10 according to one embodiment is shown. Figures 10 to 12 In some embodiments, for example, the groove 6 is minimized. Therefore, the contact area of ​​the semiconductor layer sequence 2 with the etching medium during wet chemical etching is minimized. This can reduce or prevent etching. Figures 10 to 12 In some embodiments, auxiliary structure 5 may also be generated.

[0105] Figure 10 An embodiment of a semiconductor laser array 10 having a continuous widened region 32 is shown. Alternatively, the widened region 32 can be formed by widened regions arranged spaced apart from each other, for example... Figure 11 As shown.

[0106] exist Figure 12 In one embodiment, the groove 6 on the right side extends beyond the widened region 32.

[0107] Figure 13 A schematic top view of a semiconductor layer sequence 2 in a method for manufacturing at least one semiconductor laser 1 according to another embodiment is shown. When providing the semiconductor layer sequence 2, i.e., before forming at least one main structure 4 and / or at least one auxiliary structure 5, a widened region 32 is structured in the lateral direction, and the structured portion has at least one transition portion 33 at which the sidewalls 34 of the widened region 32 extend in a curved and / or bent manner. For example, the widened region 32 has a notch 37.

[0108] Figure 14 and Figure 15 A schematic top view of a semiconductor laser array 10 according to another embodiment is shown. Figure 14 and Figure 15 The semiconductor laser array 10 is constructed by means of... Figure 13 The widened region of the semiconductor layer sequence 2 shown constitutes at least one main structure 4 and at least one auxiliary structure 5. A groove 6 is formed in the widened region 32, such that the structure of the groove 6 follows the structured portion of the widened region 32. Figure 14 In one embodiment, the main structure 4 is configured as a protrusion in the widened region 32. The main structure 4 is implemented in a stepped shape. Alternatively, as... Figure 15 As shown, the main structure 4 is not implemented as a stepped shape. In particular, the side of the main structure 4 is defined by the notch 37 of the widened region 32.

[0109] Figure 16A semiconductor laser array 10 according to another embodiment is shown. The semiconductor laser array 10 has a plurality of semiconductor lasers 1 to be manufactured. Each semiconductor laser 1 includes at least a ridge waveguide 3, wherein a main structure 4 made of a widened region 32 is arranged at the ridge waveguide 3. Here, the main structure 4 is configured as a stepped shape. The main structure 4 has a first step 43 arranged closest to the ridge waveguide and another step 44. The other step 44 is located between the first step 43 and the coupling output facet 41 of the semiconductor laser 1. The first step 43 has a lateral extension smaller than the extension of the other step 44. Figure 16 The semiconductor laser array 10 has two auxiliary structures 5 and 52 between each of two adjacent main structures 4 and 45. Alternatively, the semiconductor laser array 10 may have no auxiliary structures 5 and 52, have only one, or have multiple auxiliary structures 5 and 52 between adjacent main structures 4 and 45.

[0110] The features and embodiments described in conjunction with the accompanying drawings can be combined with each other according to other embodiments, even if not all combinations are explicitly described. Furthermore, the embodiments described in conjunction with the accompanying drawings may alternatively or additionally have other features described in the general portion of the specification.

[0111] This invention is not limited to what has been described through the embodiments. Rather, the invention includes each new feature and each combination of features (this in particular includes each combination of features in the claims), even if the feature or combination itself is not explicitly stated in the claims or embodiments.

[0112] List of reference numerals

[0113] 1. Semiconductor laser

[0114] 10 Semiconductor Laser Array

[0115] 11 multi-launchers

[0116] 12 single transmitters

[0117] 2 Semiconductor layer sequence

[0118] 21 active areas

[0119] 3-ridge waveguide

[0120] 31. Other ridge waveguides

[0121] 32 Widened Area

[0122] 33 Transition Section

[0123] 34 Widened side area

[0124] The first sub-region of the 35-ridge waveguide

[0125] 36 additional sub-regions of the ridge waveguide

[0126] 37. Widened area notch

[0127] 4 main structures

[0128] 41 Coupled Output Facet

[0129] 42 Side of the main structure

[0130] 43 First Step

[0131] 44. Other steps

[0132] 45 Other main structures

[0133] 46 resonator face

[0134] 5 Auxiliary Structures

[0135] 51 Side of auxiliary structure

[0136] 52 Other auxiliary structures

[0137] 6 grooves

[0138] 7 Etching Section

[0139] L1 separation line

[0140] L2's other separation line

Claims

1. A method for manufacturing at least one semiconductor laser (1), comprising the following steps: - A semiconductor layer sequence (2) is provided, having at least one ridge waveguide (3) and a broadened region (32), wherein the main extension direction of the broadened region (32) extends laterally or perpendicularly to the main extension direction of the ridge waveguide (3), and - At least one main structure (4) of the semiconductor laser (1) is formed by the widened region (32), wherein the main structure (4) is connected to the ridge waveguide and includes the coupling output facet (41) of the semiconductor laser (1), and wherein, - The main structure (4) is implemented as a stepped structure and has at least two steps (43, 44) along the main extension direction of the ridge waveguide (3), and / or - The widened region (32) constitutes at least one auxiliary structure (5), which is laterally spaced from the main structure (4) and has a lateral dimension less than or equal to the lateral dimension of the main structure (4) along the main extension direction of the widened region (32).

2. The method for manufacturing a semiconductor laser (1) according to the preceding claim, wherein, The coupling output facet (41) of the semiconductor laser (1) is produced by wet chemical etching.

3. The method for manufacturing a semiconductor laser (1) according to any one of the preceding claims, wherein, The at least one auxiliary structure (5) is configured as a trapezoid or semicircle in the top view of the semiconductor layer sequence (2).

4. The method for manufacturing a semiconductor laser (1) according to any one of the preceding claims, wherein, - The semiconductor layer sequence (2) includes at least two ridge waveguides (3, 31). - At least two main structures (4, 45) are formed in the widened region (23), and - At least two auxiliary structures (5, 52) are formed in the widened region (23), wherein the at least two auxiliary structures are arranged between the main structure (4) and an adjacent additional main structure (45).

5. The method for manufacturing a semiconductor laser (1) according to any one of claims 1 to 4, wherein, The main structure (4) and the at least one auxiliary structure (5) are formed in a common etching process.

6. A method for manufacturing a semiconductor laser (1) according to any one of the preceding claims, wherein, The main structure (4) has at least a partially extending crystal plane perpendicular to the main extension direction of the ridge waveguide (3), the crystal plane forming the coupling output facet (41).

7. The method for manufacturing a semiconductor laser (1) according to any one of the preceding claims, wherein, The first step (43) closest to the ridge waveguide (3) has a lateral extension smaller than the extension of the additional step (44) located between the first step (43) and the coupling output surface (41).

8. A method for manufacturing a semiconductor laser (1) according to any one of the preceding claims, wherein, The widened region (32) is structured in the lateral direction before constituting the at least one main structure (4) and / or the at least one auxiliary structure (5), and the structured portion has at least one transition portion (33) at which the side (34) of the widened region (32) extends in a curved and / or bent manner.

9. The method for manufacturing a semiconductor laser (1) according to claim 8, wherein, A groove (6) is formed in the widened region (32) such that the structure of the groove (6) follows the structure of the widened region (32).

10. A method for manufacturing a semiconductor laser (1) according to any one of the preceding claims, wherein, - Fabricate multiple semiconductor lasers in a common process (1), and - Separate the plurality of semiconductor lasers (1) into multiple emitters (11) and / or single emitters (12).

11. The method of manufacturing a semiconductor laser (1) according to the preceding claim, wherein, The at least one auxiliary structure (5) is generated laterally between the main structure (4) and another main structure (45) in the widened region (32).

12. The method of manufacturing a semiconductor laser (1) according to any one of claims 9 to 10, wherein, The at least one auxiliary structure (5) is completely retained in the separate semiconductor laser (1).

13. A semiconductor laser (1) having a semiconductor layer sequence (2), wherein, - The semiconductor layer sequence (2) has a ridge waveguide (3) and a widened region (32). - The main extension direction of the widened region (32) extends laterally or perpendicularly to the main extension direction of the ridge waveguide (3). - The semiconductor layer sequence (2) has a main structure (4), and - The main structure (4) is connected to the ridge waveguide (3), includes the coupling output facet (41) of the semiconductor laser (1), and is formed by the widened region (32), wherein, - The main structure (4) is implemented as a stepped shape and has at least two steps (43, 44) along the main extension direction of the ridge waveguide (3), and / or - The semiconductor layer sequence has at least one auxiliary structure (5), which is formed by the widened region (32), is laterally spaced from the main structure (4), and has a lateral dimension along the main extension direction of the widened region (32) that is less than or equal to the lateral dimension of the main structure (4).

14. The semiconductor laser (1) according to claim 13, wherein, The main structure (4) and / or the auxiliary structure (5) have at least one side (42, 51), and the at least one side (42, 51) extends at least partially laterally and / or perpendicularly to the main extension direction of the widened region (32).

15. The semiconductor laser (1) according to any one of claims 13 to 14, wherein, The auxiliary structure (5) is at least approximately trapezoidal, quarter-circular or semi-circular in the top view of the semiconductor layer sequence (2).

16. The semiconductor laser (1) according to any one of claims 13 to 15, wherein the semiconductor laser is implemented as a multi-emitter (11) having at least two main structures (4, 45) and at least one auxiliary structure (5), wherein, The auxiliary structure (5) is arranged at intervals from the main structure (4, 45) along the main extension direction of the widened region (32).

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