Vertical cavity surface emitting laser and preparation method thereof

Abstract

The embodiments of the present application relate to a vertical cavity surface emitting laser and a method for preparing the same. The vertical cavity surface emitting laser comprises a substrate and a resonant cavity structure provided on the substrate; the resonant cavity structure comprises a bottom reflector structure, an active layer, a photoelectric confinement layer, and a top reflector structure; the photoelectric confinement layer is provided with a photoelectric confinement pattern for defining the light-emitting area of ​​the vertical cavity surface emitting laser; the projection shape of the photoelectric confinement pattern on the substrate comprises at least a current concentration area; and an ion implantation area, which at least forms and covers the current concentration area, and the ion implantation area is configured to passivate the current concentration area. The present application forms an ion implantation area by performing ion implantation in the current concentration area, passivates the current concentration area, and improves the reverse breakdown resistance of the device.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of semiconductor laser technology, and in particular to vertical cavity surface emitting lasers and methods for preparing the same. Background Art

[0002] Vertical-cavity surface-emitting laser (VCSEL) is a new type of semiconductor laser characterized by small size, low threshold current, and easy two-dimensional integration. It is widely used in optical communications, optical interconnection and other fields.

[0003] However, the reverse breakdown voltage of VCSEL devices is still a technical indicator that needs to be improved. Improving the reverse breakdown voltage can not only enhance the reliability of the device but also expand its application range.

[0004] The above content is only used to assist in understanding the technical solution of the present invention and does not constitute an admission that the above content is prior art. Summary of the Invention

[0005] The main purpose of the present invention is to provide a vertical cavity surface emitting laser and a preparation method thereof, aiming to solve the above technical problems in the prior art.

[0006] Based on this, it is necessary to provide a vertical cavity surface emitting laser and a preparation method thereof to address the above technical problems.

[0007] In a first aspect, the present application provides a vertical cavity surface emitting laser, comprising a substrate and a resonant cavity structure provided on the substrate;

[0008] The resonant cavity structure includes a bottom reflector structure, an active layer, an optoelectronic confinement layer, and a top reflector structure; the optoelectronic confinement layer is provided with an optoelectronic confinement pattern for defining a light-emitting area of ​​the vertical cavity surface emitting laser; the projection shape of the optoelectronic confinement pattern on the substrate includes at least a current concentration area; and

[0009] An ion implantation region is formed to at least cover the current concentration region, and the ion implantation region is configured to passivate the current concentration region.

[0010] In one embodiment, the projection shape of the photoelectric confinement pattern on the substrate includes an irregular geometric shape or a regular polygon;

[0011] The current concentration region at least covers the corner positions of the irregular geometric shape; or the current concentration region at least covers the corner positions of the regular polygon.

[0012] In one embodiment, the projection shape of the photoelectric confinement pattern on the substrate is a regular polygon, and the ion implantation region at least includes a remaining region after the regular polygon is inscribed by a circle.

[0013] In one embodiment, the ion implantation region is obtained by implanting ions into the resonant cavity structure under the shielding of a mask pattern, and the projection shape of the mask pattern on the substrate includes at least one smooth curve connected end to end.

[0014] In one embodiment, the projection shape of the mask pattern on the substrate includes six smooth curves connected end to end, and the six smooth curves are divided into two groups, each group of curves has the same curvature radius, and different groups have different curvature radii.

[0015] In one embodiment, the six smooth curves are respectively recorded as a first group of curves and a second group of curves, and the curvature radius of the first group of curves is greater than the curvature radius of the second group of curves; and / or

[0016] The centers of curvature of the first set of curves and the centers of curvature of the second set of curves are located on opposite sides.

[0017] In one embodiment, the setting position of the second group of curves corresponds to the position of the corner point.

[0018] In a second aspect, the present application further provides a method for preparing a vertical cavity surface emitting laser, comprising:

[0019] Providing an epitaxial layer; wherein the epitaxial layer includes a substrate and a bottom reflector structure, an active area and a top reflector structure provided on the substrate;

[0020] Performing mesa etching on the epitaxial layer to obtain a plurality of grooves, wherein the grooves expose a portion of the surface of the bottom reflector structure;

[0021] Performing a wet oxidation process on the epitaxial layer through the trench to obtain at least one photoelectric confinement pattern; wherein the projection shape of the photoelectric confinement pattern on the substrate includes at least a current concentration region;

[0022] A mask pattern is applied on the surface of the epitaxial layer, and an ion implantation process is performed on the epitaxial layer through the mask pattern to obtain an ion implantation region; wherein the ion implantation region at least forms and covers the current concentration region.

[0023] In one embodiment, the projection shape of the mask pattern on the substrate includes at least one smooth curve connected end to end.

[0024] In one embodiment, the projection shape of the mask pattern on the substrate includes six smooth curves connected end to end, and the six smooth curves are divided into two groups, each group of curves has the same curvature radius, and different groups have different curvature radii.

[0025] In one embodiment, the six smooth curves are respectively recorded as a first group of curves and a second group of curves, and the curvature radius of the first group of curves is greater than the curvature radius of the second group of curves; and / or

[0026] The centers of curvature of the first set of curves and the centers of curvature of the second set of curves are located on opposite sides.

[0027] In one embodiment, the setting position of the second group of curves corresponds to the position of the corner point.

[0028] In one embodiment, the projection shape of the photoelectric confinement pattern on the substrate is a regular polygon, and the ion implantation region at least includes a remaining region after the regular polygon is inscribed by a circle.

[0029] The present invention has at least the following beneficial effects:

[0030] The vertical cavity surface emitting laser provided by the present invention performs ion implantation passivation on the current concentration area in the vertical cavity surface emitting laser, so that the current concentration corresponding to the photoelectric confinement pattern is destroyed, thereby improving the reverse breakdown voltage capability of the device.

[0031] In a third aspect, the present application provides a VCSEL chip comprising at least one laser array; the laser array comprises a plurality of vertical cavity surface emitting lasers as described above; the laser array is a regularly arranged array, or a randomly arranged array, or an array having multiple addressable sub-arrays.

[0032] In a fourth aspect, the present application provides a light source for a lidar system, comprising at least one vertical cavity surface emitting laser as described above or at least one VCSEL chip as described above.

[0033] In a fifth aspect, the present application provides a laser radar system, comprising a transmitting component and a receiving component, wherein the transmitting component adopts the above-mentioned light source for the laser radar system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the structure of a vertical cavity surface emitting laser in one embodiment of the present application;

[0035] Figure 2a Schematic diagram of the relative shape of OA and IMP according to one embodiment of the present application;

[0036] Figure 2b-2c A schematic diagram of an IMP shape according to an embodiment of the present application;

[0037] Figure 3 This is a flow chart of a method for manufacturing a vertical cavity surface emitting laser in one embodiment of the present application.

[0038] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0040] It should be understood that the terms "first," "second," and the like used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are used solely to distinguish a first element from another element. For example, a first client may be referred to as a second client, and similarly, a second client may be referred to as a first client, without departing from the scope of this application.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, features specified as "first" or "second" may explicitly or implicitly include at least one of such features. "Multiple" means at least two, such as two, three, etc., unless otherwise specifically defined. "Several" means at least one, such as one, two, etc., unless otherwise specifically defined.

[0042] As described in the background technology of this application, a vertical-cavity surface-emitting laser (VCSEL) is a semiconductor laser whose laser beam is emitted perpendicular to the chip surface. It has the advantages of low threshold current, high modulation bandwidth, circular spot, and easy arraying. It is widely used in optical communications, optical interconnection, 3D sensing, consumer electronics and other fields.

[0043] However, existing VCSEL structures still have some issues. In particular, when using oxide confinement (OA) technology, regular or irregular polygons are formed, and current concentrations are likely to occur at the corners of the polygons. These current-concentrated corners are more likely to cause breakdown under forward and reverse bias, especially during reverse bias testing, thus affecting device reliability. This reduces the reliability and service life of VCSEL devices under high-power or long-term operating conditions.

[0044] Based on this, see Figure 1 and Figure 2a-2cThe present application provides a vertical cavity surface emitting laser (VCSEL) comprising a substrate St and a resonant cavity structure (not shown) disposed on the substrate St. The resonant cavity structure comprises a bottom reflector structure 10, an active layer 20, an optoelectronic confinement layer, and a top reflector structure 30. The optoelectronic confinement layer is provided with an optoelectronic confinement pattern OA for defining the light-emitting area of ​​the VCSEL. The projection of the optoelectronic confinement pattern OA on the substrate includes at least a current concentration region (not shown). An ion implantation region A2 forms and covers at least the current concentration region. The ion implantation region A2 is configured to passivate the current concentration region. The ion implantation region A2 is formed by implanting hydrogen or helium ions from the side of the top mirror structure 30 into the resonant cavity structure. The implantation energy can be, for example, 50-100 KeV. The ion implantation region A2 is configured to passivate the current concentration region. Ion bombardment damages the lattice structure of the region, thereby increasing the resistivity and reducing the current flowing through the region. This prevents excessive current concentration in the region, which can lead to device performance degradation and shortened life.

[0045] In this specific embodiment, please refer to Figure 3 The bottom reflector structure 10 and the top reflector structure 30 define the resonant cavity structure of the vertical cavity surface emitting laser of the present application, that is, the area between the bottom reflector structure 10 and the top reflector structure 30 is the resonant cavity. The resonant cavity is used to generate standing waves. Standing waves are waves formed by two coherent waves propagating in opposite directions on the same straight line and superimposed on each other. Specifically, when the two waves are in phase, their amplitudes add together to form antinodes (i.e., crests). When the two waves are in opposite phases, their amplitudes subtract from each other to form nodes (i.e., troughs). Therefore, the positions of the crests and troughs of the standing wave are fixed.

[0046] In one embodiment, the bottom reflector structure 10 may include a periodically stacked DBR structure, that is, a plurality of reflectors with an optical thickness of one-quarter the laser wavelength, and the plurality of reflectors are arranged alternately according to high and low refractive indices. The top reflector structure 30 also includes a periodically stacked DBR structure, that is, a plurality of reflectors with an optical thickness of one-quarter the laser wavelength, and the plurality of reflectors are arranged alternately according to high and low refractive indices. It can be understood that the components, number of stacking periods, etc. of the DBR structure of the bottom reflector structure 10 and the DBR structure of the top reflector structure 30 may be the same or different, and this embodiment does not limit this. Among them, the material of the top reflector structure 30 and the bottom reflector structure 10 can be a dielectric material with electrical insulation, for example, it can include silicon nitride, silicon oxide, aluminum oxide or titanium oxide. The material of the top reflector structure 30 and the bottom reflector structure 10 can also be a semiconductor material, for example, it can include GaAs and AlGaAs.

[0047] The material of the substrate St includes, but is not limited to, GaAs, InP, Si, etc. The bottom reflector structure 10 and the top reflector structure 30 may include a film layer with a periodically varying refractive index to achieve efficient reflection or transmission of light within a specific wavelength range. The film layer with a periodically varying refractive index can be composed of semiconductor materials, dielectric materials, metal-dielectric hybrid materials, etc. For example, the bottom reflector structure 10 can be an N-type semiconductor layer, and the top reflector structure 30 can be a P-type semiconductor layer. For another example, the bottom reflector structure 10 can be a P-type semiconductor layer, and the top reflector structure 30 can be an N-type semiconductor layer. Alternatively, the materials of the N-type semiconductor layer and the P-type semiconductor layer can be, but are not limited to, GaAs, AlGaAs, etc., and are not limited here. As long as the resonant cavity can be defined, it falls within the scope of protection of this embodiment. In this specific embodiment, the substrate St can be made of GaAs material with a thickness between 400 and 600 microns, for example, 500 microns. The bottom reflector structure 10 can be composed of 30 to 40 pairs of AlGaAs / GaAs stacked together. The top reflector structure 30 may be formed by, for example, 20 to 30 pairs of AlGaAs / GaAs stacks.

[0048] The active layer 20 comprises a multi-quantum well structure composed of GaAs / AlGaAs materials, with 3-5 quantum wells. The multi-quantum well structure is used to generate stimulated emission of photons. The emitted photons are continuously reflected in the resonant cavity defined by the bottom reflector structure 10 and the top reflector structure 30, and are continuously enhanced during the reflection process, ultimately emitting laser light at a specific wavelength and with sufficient energy.

[0049] The multi-quantum well structure is where laser gain amplification is generated, and the center position of the multi-quantum well structure can be aligned with the position where the light field is strongest to achieve a greater amplification effect. Furthermore, in the case of multiple multi-quantum well structures, the confinement factors of the multi-quantum well structures in the same section of the light field are within the same preset range, that is, the confinement factors of each multi-quantum well structure are maintained at the same level, so that the contribution of each multi-quantum well structure to luminescence is similar. It can be understood that similar luminescence contributions mean that the injection of current into each multi-quantum well structure is more uniform, which helps to reduce the threshold current of the device, thereby reducing the power consumption of the device and extending its service life. Moreover, when the contribution of each multi-quantum well structure to luminescence is similar, the distribution of carriers in each multi-quantum well structure will be more uniform, which helps to reduce the recombination loss of carriers, thereby improving the overall luminescence efficiency of the device.

[0050] The photoelectric confinement layer is formed in the top reflector structure 30. Specifically, the photoelectric confinement layer is located on the side of the corresponding active layer 20 away from the substrate St to limit the flow of current, so that the current flows only within the luminescent region defined by the photoelectric confinement layer 132, thereby reducing unnecessary energy consumption, thereby reducing the threshold current and increasing the current density. Moreover, the photoelectric confinement layer can also confine the light field to the luminescent region defined by the photoelectric confinement layer, reducing light scattering and diffraction, thereby optimizing the divergence angle of the device and improving the beam quality. Typically, the photoelectric confinement layer is set at the location with the lowest light field intensity, that is, at the trough of the standing wave, so that it has a smaller confinement factor, which helps to reduce the divergence angle of the device.

[0051] Photoelectric confinement layers can include any of air column-type, oxide-type, ion-implanted, and tunnel junction-type confinement layers. Air column-type confinement layers confine current and light through air columns, hollow structures formed through dry etching techniques. The air columns have a lower refractive index than the surrounding semiconductor material, effectively confining light to the central region. Ion-implanted confinement layers modify the electrical properties of semiconductor materials by injecting ions into them, creating high-resistance regions that restrict current flow and thus indirectly limit the light generation region.

[0052] In one embodiment, the oxidation-restricted photoelectric confinement layer includes an unoxidized region of AlGaAs material with a high Al content and an oxidized region of aluminum oxide material. The oxidized region is arranged outside the unoxidized region, and the unoxidized region forms a light-emitting region for effective current injection. Among them, the semiconductor layer in the unoxidized region of the photoelectric confinement layer can be understood as a photoelectric confinement pattern OA, which is used to define the light-emitting region of the vertical cavity surface emitting laser. When current enters, the current can only flow to the active layer 20 through the photoelectric confinement pattern OA in the photoelectric confinement layer, thereby achieving the limitation of the current injection path and the optical mode field. Furthermore, the AlGaAs layer with a high aluminum content can be converted into aluminum oxide through a selective oxidation process to form an outer unoxidized region.

[0053] In one embodiment, the tunnel junction type photoelectric confinement layer includes at least one highly doped N-type structure layer and at least one highly doped P-type structure layer. Specifically, a potential barrier is formed between the highly doped N-type structure layer and the highly doped P-type structure layer, and electrons are allowed to pass through the potential barrier by tunneling, thereby achieving lateral confinement of the current. In one embodiment, the material of the N-type structure layer and the P-type structure layer is Al x Ga 1-x As, the doping concentration of the N-type structure layer and the P-type structure layer is greater than 1e 18 cm -3 , where 0≤x≤1.

[0054] In one embodiment, the projection shape of the photoelectric confinement pattern OA on the substrate St includes an irregular geometric shape or a regular polygon. For example, when the projection shape of the photoelectric confinement pattern OA on the substrate St is an irregular geometric shape, the irregular geometric shape can be a hexagon, a pentagon, a spindle, a teardrop, a concave quadrilateral, a diamond, etc.; when the projection shape of the photoelectric confinement pattern OA on the substrate St is a regular polygon, the regular polygon can be a regular triangle, a square, a rectangle, a regular pentagon, a regular hexagon, a regular heptagon, a regular octagon, etc. It can be understood that whether it is an irregular geometric shape or a regular polygon, there will basically be a corner point in the pattern, that is, the intersection of two adjacent sides. The position of the corner point is a place where current is easily concentrated, that is, the current concentration area described in this application. When a forward bias or a reverse bias is applied to the device, it is more likely to cause voltage breakdown in the current concentration area, which is not conducive to the overall life and reliability of the device. Furthermore, the current concentration region at least covers the corner positions of the irregular geometric shape; or the current concentration region at least covers the corner positions of the regular polygon. In other words, the current concentration region at least includes the focal position of the current limiting pattern OA.

[0055] As an example, see Figure 2a When the projection shape of the photoelectric confinement pattern OA on the substrate is a regular polygon, such as an equilateral triangle or a regular hexagon, the ion implantation area A2 at least includes the remaining area after the regular polygon is inscribed by a circle. Figure 2a As shown, when the photoelectric confinement pattern OA is a regular hexagon, the ion implantation area A2 is Figure 2a In the case of the black filled area, the six corner points of the original regular hexagon can be passivated so that current does not flow through or is greatly limited to flow through the ion implantation area A2.

[0056] As an example, the ion implantation area A2 is obtained by implanting ions into the resonant cavity structure under the shielding of a mask pattern IMP, and the projection shape of the mask pattern IMP on the substrate St includes at least one smooth curve connected end to end. Specifically, when a smooth curve connected end to end is included, the smooth area can be a circle ( Figure 2a ).

[0057] As an example, the projection shape of the mask pattern IMP on the substrate St may include six segments of smooth curves connected end to end, and the six segments of smooth curves are divided into two groups, each group of curves has the same curvature radius, and different groups have different curvature radiuses. Figure 2b and Figure 2cThe six smooth curves are respectively recorded as the first group of curves S1 and the second group of curves S2. The setting position of the second group of curves S2 corresponds to the position of the aforementioned corner points. However, the number of curves in the second group of curves S2 can be equal to the number of corner points, or they can be unequal. For example, if they are equal, there are six curves in the second group of curves S2. If they are unequal, there are three curves in the second group of curves S2 (e.g. Figure 2b 、 2c As an example, the curvature radius of the first set of curves S1 is greater than the curvature radius of the second set of curves S2; further, Figure 2b and Figure 2c In the second set of curves S2, the curvature radii of the curves are different. Figure 2b The radius of curvature is less than Figure 2c The curvature radius in the curve is larger, which can make the connection between different groups of curves smoother and avoid introducing new corner points. Figure 2b and Figure 2c In the example, the intersection of the first set of curves S1 and the second set of curves S2 should be smooth, without sharp corners, forming an "S"-shaped effect. Furthermore, the center of curvature of the first set of curves S1 and the center of curvature of the second set of curves S2 are located on opposite sides. Furthermore, when multiple VCSELs are arrayed, adjacent second set of curves S2 may form a Via region. This can be understood by referring to related art and will not be elaborated in this application.

[0058] Second, please refer to Figure 3 , the present application also provides a method for preparing a vertical cavity surface emitting laser, comprising steps S10-S40:

[0059] Step S10, providing an epitaxial layer; wherein the epitaxial layer includes a substrate and a bottom reflector structure, an active region, and a top reflector structure provided on the substrate;

[0060] Step S20, performing mesa etching on the epitaxial layer to obtain a plurality of grooves, wherein the grooves expose a portion of the surface of the bottom reflector structure;

[0061] Step S30, performing a wet oxidation process on the epitaxial layer through the trench to obtain at least one photoelectric confinement pattern; wherein the projection shape of the photoelectric confinement pattern on the substrate includes at least a current concentration region;

[0062] In step S40 , a mask pattern is applied on the surface of the epitaxial layer, and an ion implantation process is performed on the epitaxial layer through the mask pattern to obtain an ion implantation region. The ion implantation region at least forms and covers the current concentration region.

[0063] Specifically, if Figure 3As shown, the complete preparation method in this specific embodiment can generally include the steps of epitaxial growth, oxidative trench etching, wet oxidation, deep trench etching, deep trench ion implantation, and conductive portion fabrication. The epitaxial growth, MESA trench etching, wet oxidation, deep trench etching, and deep trench ion implantation processes can be understood with reference to the existing VCSEL process, and this embodiment does not specifically improve these steps. The key improvement of this application lies in the ion implantation step after wet oxidation.

[0064] For example, when performing the oxide trench etching, an inductively coupled plasma etching technique can be used. The etching gas is a Cl2 / BCl3 mixed gas. The etching depth is controlled at 5-8 microns, so that the bottom of the oxide trench just exposes the top of the bottom reflector structure 10. A wet oxidation process is performed on the epitaxial layer through the trench 10 to obtain a photoelectric confinement pattern OA. The wet oxidation can be performed at a temperature of 420°C, the oxidation atmosphere is a mixed gas of water vapor and nitrogen, and the oxidation time is 30-60 minutes. The oxidation process expands inward from the sidewalls of the oxide trench, eventually forming a photoelectric confinement pattern OA with an irregular geometric shape or a regular polygon.

[0065] Furthermore, hydrogen ions can be used for ion implantation, with an implantation energy of 80 keV and an implantation dose of 3×10 14 cm -2 The mask pattern may be made of a photoresist material (PR) with a thickness of 2-3 microns.

[0066] As an example, the projection shape of the mask pattern IMP on the substrate St includes at least one smooth curve connected end to end. Specifically, when including a smooth curve connected end to end, the smooth area can be a circle ( Figure 2a ).

[0067] As an example, the projection shape of the mask pattern IMP on the substrate St may include six segments of smooth curves connected end to end, and the six segments of smooth curves are divided into two groups, each group of curves has the same curvature radius, and different groups have different curvature radiuses. Figure 2b and Figure 2c The six smooth curves are respectively recorded as the first group of curves S1 and the second group of curves S2. The setting position of the second group of curves S2 corresponds to the position of the aforementioned corner points. However, the number of curves in the second group of curves S2 can be equal to the number of corner points, or they can be unequal. For example, if they are equal, there are six curves in the second group of curves S2. If they are unequal, there are three curves in the second group of curves S2 (e.g. Figure 2b 、 2cAs an example, the curvature radius of the first set of curves S1 is greater than the curvature radius of the second set of curves S2; further, Figure 2b and Figure 2c In the second set of curves S2, the curvature radii of the curves are different. Figure 2b The radius of curvature is less than Figure 2c The curvature radius in the curve is larger, which can make the connection between different groups of curves smoother and avoid introducing new corner points. Figure 2b and Figure 2c In the example, the intersection of the first set of curves S1 and the second set of curves S2 should be smooth, without sharp corners, forming an "S"-shaped effect. Furthermore, the center of curvature of the first set of curves S1 and the center of curvature of the second set of curves S2 are located on opposite sides. Furthermore, when multiple VCSELs are arrayed, adjacent second set of curves S2 may form a Via region. This can be understood by referring to related art and will not be elaborated in this application.

[0068] As an example, see Figure 2a When the projection shape of the photoelectric confinement pattern OA on the substrate is a regular polygon, such as an equilateral triangle or a regular hexagon, the ion implantation area A2 at least includes the remaining area after the regular polygon is inscribed by a circle. Figure 2a As shown, when the photoelectric confinement pattern OA is a regular hexagon, the ion implantation area A2 is Figure 2a In the case of the black filled area, the six corner points of the original regular hexagon can be passivated so that current does not flow through or is greatly limited to flow through the ion implantation area A2.

[0069] The present invention has at least the following beneficial effects:

[0070] The vertical cavity surface emitting laser provided by the present invention performs ion implantation passivation on the current concentration area in the vertical cavity surface emitting laser, so that the current concentration corresponding to the photoelectric confinement pattern is destroyed, thereby improving the reverse breakdown voltage capability of the device.

[0071] It should be understood that although Figure 3 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 3At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0072] In a third aspect, the present application provides a VCSEL chip comprising at least one laser array; the laser array comprises a plurality of vertical cavity surface emitting lasers as described above; the laser array is a regularly arranged array, a randomly arranged array, or an array having multiple addressable sub-arrays. Based on the aforementioned vertical cavity surface emitting lasers, the VCSEL chip of this embodiment has good reliability.

[0073] In a fourth aspect, the present application provides a light source for a lidar system, comprising at least one vertical cavity surface emitting laser as described above or at least one VCSEL chip as described above.

[0074] In a fifth aspect, the present application provides a laser radar system, comprising a transmitting component and a receiving component, wherein the transmitting component adopts the above-mentioned light source for the laser radar system.

[0075] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The above-described embodiments merely represent several implementation methods of the embodiments of the present application. The descriptions thereof are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the concept of the embodiments of the present application, and these all fall within the scope of protection of the embodiments of the present application. Therefore, the scope of protection of the patent of the embodiments of the present application shall be based on the appended claims.

Claims

1. A vertical cavity surface emitting laser, characterized in that: comprising a substrate and a resonant cavity structure provided on the substrate; The resonant cavity structure includes a bottom reflector structure, an active layer, an optoelectronic confinement layer, and a top reflector structure; the optoelectronic confinement layer is provided with an optoelectronic confinement pattern for defining the light-emitting area of ​​the vertical cavity surface emitting laser; the projection shape of the optoelectronic confinement pattern on the substrate includes at least a current concentration area; as well as An ion implantation region is formed to at least cover the current concentration region, and the ion implantation region is configured to passivate the current concentration region.

2. The vertical cavity surface emitting laser according to claim 1, wherein: The projection shape of the photoelectric confinement pattern on the substrate includes an irregular geometric shape or a regular polygon; The current concentration region at least covers the corner positions of the irregular geometric shape; or the current concentration region at least covers the corner positions of the regular polygon.

3. The vertical cavity surface emitting laser according to claim 2, characterized in that: The projection shape of the photoelectric confinement pattern on the substrate is a regular polygon, and the ion implantation region at least includes a remaining region after the regular polygon is inscribed by a circle.

4. The vertical cavity surface emitting laser according to claim 2, wherein: The ion implantation region is obtained by implanting ions into the resonant cavity structure under the shielding of a mask pattern, and the projection shape of the mask pattern on the substrate includes at least one smooth curve connected end to end.

5. The vertical cavity surface emitting laser according to claim 4, characterized in that: The projection shape of the mask pattern on the substrate includes six smooth curves connected end to end, and the six smooth curves are divided into two groups. The curvature radius of each group of curves is the same, and the curvature radius of different groups is different.

6. The vertical cavity surface emitting laser according to claim 5, characterized in that: The six smooth curves are respectively recorded as a first group of curves and a second group of curves, wherein the curvature radius of the first group of curves is greater than the curvature radius of the second group of curves; and / or The centers of curvature of the first set of curves and the centers of curvature of the second set of curves are located on opposite sides.

7. The vertical cavity surface emitting laser according to claim 6, characterized in that The setting positions of the second group of curves correspond to the positions of the corner points.

8. A method for preparing a vertical cavity surface emitting laser, characterized in that: include: Providing an epitaxial layer; wherein the epitaxial layer includes a substrate and a bottom reflector structure, an active area and a top reflector structure provided on the substrate; Performing mesa etching on the epitaxial layer to obtain a plurality of grooves, wherein the grooves expose a portion of the surface of the bottom reflector structure; Performing a wet oxidation process on the epitaxial layer through the trench to obtain at least one photoelectric confinement pattern; wherein the projection shape of the photoelectric confinement pattern on the substrate includes at least a current concentration region; A mask pattern is applied on the surface of the epitaxial layer, and an ion implantation process is performed on the epitaxial layer through the mask pattern to obtain an ion implantation region; wherein the ion implantation region at least forms and covers the current concentration region.

9. The method for preparing a vertical cavity surface emitting laser according to claim 8, wherein: The projection shape of the mask pattern on the substrate includes at least one smooth curve connected end to end.

10. The method for preparing a vertical cavity surface emitting laser according to claim 9, wherein: The projection shape of the mask pattern on the substrate includes six smooth curves connected end to end, and the six smooth curves are divided into two groups. The curvature radius of each group of curves is the same, and the curvature radius of different groups is different.

11. The method for preparing a vertical cavity surface emitting laser according to claim 10, wherein: The six smooth curves are respectively recorded as a first group of curves and a second group of curves, wherein the curvature radius of the first group of curves is greater than the curvature radius of the second group of curves; and / or The centers of curvature of the first set of curves and the centers of curvature of the second set of curves are located on opposite sides.

12. The method for preparing a vertical cavity surface emitting laser according to claim 11, wherein: The second set of curves are arranged at positions corresponding to corner points of the photoelectric confinement pattern.

13. The method for preparing a vertical cavity surface emitting laser according to claim 8, wherein: The projection shape of the photoelectric confinement pattern on the substrate is a regular polygon, and the ion implantation region at least includes a remaining region after the regular polygon is inscribed by a circle.

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