Surface emitting laser and preparation method thereof

Abstract

The embodiment of the invention relates to a surface emitting laser and a preparation method thereof. The surface emitting laser comprises a substrate and a resonant cavity structure arranged on the substrate, the resonant cavity structure comprises a first reflecting mirror layer, an active layer and a second reflecting mirror layer which are sequentially positioned on the substrate; a photoelectric limiting layer is formed in the second reflector layer, the photoelectric limiting layer is of a polygonal annular structure, and the inner ring of the photoelectric limiting layer comprises at least three inner angles; the second reflector layer further comprises a non-ion injection area of an inclined cylinder, and the non-ion injection area of the inclined cylinder does not coincide with at least one inner angle of the at least three inner angles of the inner ring of the photoelectric limiting layer. In the second reflector layer, the area outside the non-ion injection area of the inclined cylinder is an ion injection area. According to the invention, the non-ion implantation region of the inclined cylinder is formed in the second reflector layer; therefore, the current concentration condition of the corresponding photoelectric limiting layer is damaged, and the reverse breakdown voltage resistance of the device is improved.

Description

Technical Field

[0001] Embodiments of the present application relate to the technical field of semiconductor lasers, and in particular to surface-emitting lasers and their manufacturing methods. Background Art

[0002] A vertical-cavity surface-emitting laser (VCSEL) is a new type of semiconductor laser, which is characterized by small size, low threshold current, easy two-dimensional integration, etc., and is widely used in fields such as optical communication and optical interconnection.

[0003] However, the reverse breakdown voltage of VCSEL devices is still a technical index 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 represent an admission that the above content is prior art. Summary of the Invention

[0005] The main object of the present invention is to provide a surface-emitting laser and its manufacturing method, aiming to solve the above technical problems in the prior art.

[0006] Based on this, it is necessary to provide a surface-emitting laser and its manufacturing method for the above technical problems.

[0007] In a first aspect, the present application provides a surface-emitting laser, including a substrate and a resonant cavity structure disposed on the substrate; The resonant cavity structure includes a first mirror layer, an active layer, and a second mirror layer sequentially located on the substrate; A photoelectric confinement layer is formed in the second mirror layer, the photoelectric confinement layer is a polygonal ring structure, and the inner ring of the photoelectric confinement layer includes at least three interior angles; and The second mirror layer further includes a non-ion-implanted region of inclined cylinders, and the non-ion-implanted region of inclined cylinders does not coincide with at least one of the at least three interior angles of the inner ring of the photoelectric confinement layer; In the second mirror layer, the region outside the non-ion-implanted region of inclined cylinders is an ion-implanted region.

[0008] In one embodiment, the shape of the inner ring of the photoelectric confinement layer includes an irregular polygon or a regular polygon; The region where the non-ion-implanted region of inclined cylinders intersects with the photoelectric confinement layer does not include at least one interior angle of the inner ring of the photoelectric confinement layer.

[0009] In one embodiment, a C-shaped contact metal pad is further included on the second mirror layer, and an opening of the C-shaped contact metal pad faces the first inner angle, where the first inner angle is an inner angle of an inner ring of the optical confinement layer in a region where a non-ion-implanted region of the inclined cylinder intersects with the optical confinement layer.

[0010] In one embodiment, a shape of a surface of the second mirror layer where a non-ion-implanted region of the inclined cylinder is away from the active layer does not include any inner angle of an inner ring of the optical confinement layer in a projection region on the optical confinement layer.

[0011] In one embodiment, a shape of an inner ring of the optical confinement layer is a regular polygon, and a projection of a shape of a surface of the second mirror layer where a non-ion-implanted region of the inclined cylinder is away from the active layer on the optical confinement layer is an inscribed circle of the inner ring of the optical confinement layer.

[0012] In one embodiment, an inclination angle of a column body of a non-ion-implanted region of the inclined cylinder with respect to a vertical direction of an upper surface of the second mirror layer is 2° - 7°.

[0013] In a second aspect, the present application further provides a method for manufacturing a surface-emitting laser, including: Providing an epitaxial layer; wherein, the epitaxial layer includes a substrate and a first mirror layer, an active region, and a second mirror layer that are sequentially disposed on the substrate; Performing mesa etching on the epitaxial layer to obtain a plurality of trenches, where a part of a surface of the first mirror layer is exposed by the trenches; Performing a wet oxidation process on the epitaxial layer through the trenches to form an optical confinement layer in the second mirror layer; wherein, the optical confinement layer is a polygonal ring structure, and an inner ring of the optical confinement layer includes at least three inner angles; Applying a mask pattern on a surface of the epitaxial layer, and performing an ion implantation process on the epitaxial layer through the mask pattern to form a non-ion-implanted region of an inclined cylinder in the second mirror layer; Wherein, a region outside the non-ion-implanted region of the inclined cylinder is an ion-implanted region.

[0014] In one embodiment, the trenches are an irregular polygon or a regular polygon connected end to end.

[0015] In one embodiment, before performing the mesa etching on the epitaxial layer, the method further includes: forming a C-shaped contact metal pad on the second mirror layer.

[0016] In one embodiment, in the step of performing an ion implantation process on the epitaxial layer through the mask pattern, the angle of the ion implantation is inclined 2°-7° relative to the vertical direction of the upper surface of the second mirror layer.

[0017] The present invention has at least the following beneficial effects: The surface-emitting laser provided by the present invention forms a non-ion-implanted region with inclined cylinders in the second mirror layer, which disrupts the current concentration situation of the corresponding optical confinement layer and improves the reverse breakdown voltage resistance of the device.

[0018] In a third aspect, the present application provides a VCSEL chip, including at least one laser array; the laser array includes a plurality of surface-emitting lasers as described above; the laser array is a regularly arranged array, or a randomly arranged array, or an array having a plurality of addressable sub-arrays.

[0019] In a fourth aspect, the present application provides a light source for a lidar system, including at least one surface-emitting laser as described above or at least one VCSEL chip as described above.

[0020] In a fifth aspect, the present application provides a lidar system, including a transmitting component and a receiving component, and the transmitting component uses the light source for a lidar system as described above. Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of a surface-emitting laser in an embodiment of the present application; Figure 2 It is a top view schematic diagram of a surface-emitting laser in an embodiment of the present application; Figure 3 It is a distribution schematic diagram of the non-ion-implanted region A1 and the ion-implanted region A2 of the surface-emitting laser in an embodiment of the present application on the side of the second mirror layer far from the active layer; Figure 4 It is a distribution schematic diagram of the non-ion-implanted region A1 and the ion-implanted region A2 of the surface-emitting laser in an embodiment of the present application on the side of the second mirror layer close to the active layer; Figure 5 It is a schematic diagram of performing an ion implantation process on the epitaxial layer through the mask pattern of the surface-emitting laser in an embodiment of the present application; Figure 6 It is a flowchart of the manufacturing method of the surface-emitting laser in an embodiment of the present application.

[0022] The realization of the object, functional characteristics and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0023] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be 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 the present application and are not used to limit the present application.

[0024] It can be understood that the terms "first", "second", etc. used in the present application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of the present application, the first client may be referred to as the second client, and similarly, the second client may be referred to as the first client.

[0025] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. The meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. The meaning of "several" is at least one, such as one, two, etc., unless otherwise specifically defined.

[0026] As described in the background art of the present application, a vertical-cavity surface-emitting laser (VCSEL) is a semiconductor laser whose laser beam is emitted perpendicular to the chip surface, and has advantages such as low threshold current, high modulation bandwidth, circular spot, and easy arraying, and is widely used in the fields of optical communication, optical interconnection, 3D sensing, consumer electronics, etc.

[0027] However, there are still some problems in the existing VCSEL structures. Especially when using the oxide confinement (OA) technology, regular or irregular polygons will be formed, and current concentration regions are likely to be generated at the corner positions of the polygons. These current-concentrated corners are more likely to cause breakdown during forward bias and reverse bias, especially during reverse bias testing, thereby affecting the reliability of the device. This results in a reduction in the reliability of the VCSEL device under high-power or long-term working conditions and a shortening of the service life.

[0028] Based on this, please refer to Figure 1The present application provides a surface-emitting laser, which includes a substrate St and a resonant cavity structure (not shown in the figure) disposed on the substrate St; the resonant cavity structure includes a first mirror layer 10, an active layer 20, and a second mirror layer 30; a photoelectric confinement layer is formed in the second mirror layer, the photoelectric confinement layer is a polygonal ring structure, and the inner ring of the photoelectric confinement layer includes at least three interior angles; the photoelectric confinement layer is provided with a photoelectric confinement pattern OA for defining the light-emitting area of the surface-emitting laser; the second mirror layer further includes a non-ion-implanted area A1 of inclined cylinders, and the non-ion-implanted area A1 of the inclined cylinders does not coincide with at least one of the at least three interior angles of the inner ring of the photoelectric confinement layer; in the second mirror layer, the area outside the non-ion-implanted area of the inclined cylinders is an ion-implanted area A2, that is, the non-ion-implanted area A1 of the inclined cylinders is surrounded by the ion-implanted area A2. The ion-implanted area A2 is formed by implanting hydrogen ions or helium ions into the resonant cavity structure from the second mirror layer 30 towards the substrate at a certain inclination angle through a mask, and the implantation energy can be exemplified as 50-100 keV. The ion-implanted area A2 is configured as a non-conductive area or a passivated current concentration area, and the lattice structure of this area is damaged by ion bombardment, thereby increasing the resistivity and reducing the current passing through this area, so as to form a non-ion-implanted area of inclined cylinders in the area of the second mirror layer other than the ion-implanted area; the current concentration situation corresponding to the photoelectric confinement layer is destroyed, and the reverse breakdown voltage resistance ability of the device is improved.

[0029] In this specific embodiment, the first mirror layer 10 and the second mirror layer 30 define the resonant cavity structure of the surface-emitting laser of the present application, that is, the area between the first mirror layer 10 and the second mirror layer 30 is the resonant cavity. The resonant cavity is used to generate a standing wave, and a standing wave is a wave formed by two coherent waves propagating in opposite directions on the same straight line and superimposing on each other. Specifically, when the phases of the two waves are the same, their amplitudes are added to form a wave crest (i.e., a wave peak). When the phases of the two waves are opposite, their amplitudes are subtracted to form a wave node (i.e., a wave trough). Therefore, the positions of the wave peaks and wave troughs of the standing wave are fixed.

[0030] In one embodiment, the first mirror layer 10 may include a periodically stacked DBR structure, that is, it includes a plurality of mirrors with an optical thickness of a quarter of the lasing wavelength, and the plurality of mirrors are alternately arranged with high and low refractive indices. The second mirror layer 30 also includes a periodically stacked DBR structure, that is, a plurality of mirrors with an optical thickness of a quarter of the lasing wavelength, and the plurality of mirrors are alternately arranged with high and low refractive indices. It can be understood that the components, the number of stacking periods, etc. of the DBR structure of the first mirror layer 10 and the DBR structure of the second mirror layer 30 may be the same or different, which is not limited in this embodiment. Among them, the materials of the second mirror layer 30 and the first mirror layer 10 may be dielectric materials with electrical insulation properties, such as silicon nitride, silicon oxide, aluminum oxide, or titanium oxide, etc. The materials of the second mirror layer 30 and the first mirror layer 10 may also be semiconductor materials, such as GaAs and AlGaAs.

[0031] Among them, the material of the substrate St includes but is not limited to GaAs, InP, Si, etc. The first mirror layer 10 and the second mirror layer 30 may include film layers with periodically varying refractive indices to achieve efficient reflection or transmission of light within a specific wavelength range. The film layers with periodically varying refractive indices can be composed of semiconductor materials, dielectric materials, metal-dielectric hybrid materials, etc. For example, the first mirror layer 10 may be an N-type semiconductor layer, and the second mirror layer 30 may be a P-type semiconductor layer. Another example is that the first mirror layer 10 may be a P-type semiconductor layer, and the second mirror layer 30 may be an N-type semiconductor layer. Optionally, the materials of the N-type semiconductor layer and the P-type semiconductor layer may be but are not limited to GaAs, AlGaAs, etc., which is not limited here as long as the resonator can be defined, and all belong to the protection scope of this embodiment. In this specific embodiment, the substrate St may be made of GaAs material with a thickness between 400 microns and 600 microns, for example, the thickness is 500 microns. The first mirror layer 10 may be exemplified by being stacked by 30 to 40 pairs of AlGaAs / GaAs. The second mirror layer 30 may be exemplified by being stacked by 20 to 30 pairs of AlGaAs / GaAs.

[0032] The active layer 20 includes a multi-quantum well structure, which is composed of GaAs / AlGaAs materials, and the number of quantum wells is 3 - 5. The multi-quantum well structure is used to generate stimulated emission photons, and the emitted photons are continuously reflected in the resonator defined by the first mirror layer 10 and the second mirror layer 30, and are continuously enhanced during the reflection process, so as to finally emit laser light at a specific wavelength and with sufficient energy.

[0033] The multi - quantum well structure is the place where laser gain amplification occurs. The central position of the multi - quantum well structure can be aligned with the position where the optical field is the strongest to achieve a greater amplification effect. Further, in the case of including multiple multi - quantum well structures, the confinement factor of the multi - quantum well structures in the same optical field is 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 current injection in 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.

[0034] The optical - electrical confinement layer is formed in the second mirror layer 30. Specifically, the optical - electrical 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 only flows within the light - emitting region defined by the optical - electrical confinement layer 132, thereby reducing unnecessary energy consumption, further reducing the threshold current, and increasing the current density. Moreover, the optical - electrical confinement layer can also confine the optical field within the light - emitting region defined by the optical - electrical confinement layer, reducing the scattering and diffraction of light, thereby optimizing the divergence angle of the device and improving the beam quality. Usually, the optical - electrical confinement layer is set at the position where the optical field intensity is the lowest, that is, at the trough of the standing wave, so that it has a small confinement factor, which helps to reduce the divergence angle of the device.

[0035] The optical - electrical confinement layer can include any one of an air - column - type optical - electrical confinement layer, an oxidation - confinement - type optical - electrical confinement layer, an ion - implantation - type optical - electrical confinement layer, and a tunnel - junction - type optical - electrical confinement layer. Among them, the air - column - type optical - electrical confinement layer realizes the confinement of current and light through air columns. The air columns are hollow structures formed by dry - etching technology, and their refractive index is lower than that of the surrounding semiconductor materials, thereby effectively confining the light within the central region. The ion - implantation - type optical - electrical confinement layer changes its electrical properties by implanting ions into the semiconductor material to form a high - resistance region, and the high - resistance region can limit the flow of current, thereby indirectly limiting the light - generating region.

[0036] In one embodiment, the oxidation-limited optoelectronic confinement layer includes an unoxidized region made of AlGaAs with a high Al component and an oxidized region made of aluminum oxide. The oxidized region is disposed outside the unoxidized region, and the unoxidized region forms a light-emitting region for effective current injection. Herein, the semiconductor layer of the unoxidized region in the optoelectronic confinement layer can be understood as an optoelectronic confinement pattern OA, and the optoelectronic confinement pattern OA is used to define the light-emitting region of the surface-emitting laser. When current enters, the current can only flow to the active layer 20 through the optoelectronic confinement pattern OA in the optoelectronic confinement layer, thereby realizing the confinement of the current injection path and the optical mode field. Further, through a selective oxidation process, the AlGaAs layer with a high aluminum component can be converted into aluminum oxide to form the peripheral unoxidized region.

[0037] In one embodiment, the tunnel-junction optoelectronic confinement layer includes at least one highly doped N-type structural layer and at least one highly doped P-type structural layer. Specifically, a potential barrier is formed between the highly doped N-type structural layer and the highly doped P-type structural layer, and electrons are allowed to pass through the potential barrier through the tunnel effect, thereby realizing the lateral confinement of the current. In one embodiment, the materials of the N-type structural layer and the P-type structural layer are selected as Al x Ga 1-x As, and the doping concentration of the N-type structural layer and the P-type structural layer is greater than 1e 18 cm -3 , where 0 ≤ x ≤ 1.

[0038] In one embodiment, the shape of the inner ring of the optoelectronic confinement layer includes an irregular polygon or a regular polygon; the region where the non-ion-implanted region of the inclined cylinder intersects the optoelectronic confinement layer does not include at least one inner angle of the inner ring of the optoelectronic confinement layer.

[0039] Exemplarily, when the projected shape of the optoelectronic confinement pattern OA on the substrate St is an irregular geometric shape, the irregular geometric shape can be a hexagon, pentagon, spindle shape, water droplet shape, concave quadrilateral, diamond shape, etc.; when the projected shape of the optoelectronic confinement pattern OA on the substrate St is a regular polygon, the regular polygon can be an equilateral triangle, square, rectangle, regular pentagon, regular hexagon, regular heptagon, regular octagon, etc. It can be understood that whether it is an irregular geometric shape or a regular polygon, there will basically be corner points in the pattern, that is, the intersection points of two adjacent sides. The corner point position is a place where current is prone to concentrate, which is the current concentration region described in the present application. When a forward bias or reverse bias is applied to the device, a voltage breakdown phenomenon is more likely to occur in the current concentration region, which is not conducive to the overall life and reliability of the device. Further, the current concentration region at least covers the corner point position of the irregular geometric shape; or the current concentration region at least covers the corner point position of the regular polygon. That is to say, the current concentration region at least includes the focal point position of the current confinement pattern OA.

[0040] In one embodiment, the non-ion-implanted region of the inclined column is far from the active layer, and the shape of the projection region of the active layer on the surface of the second mirror layer in the optoelectronic confinement layer does not include any interior angle of the inner ring of the optoelectronic confinement layer.

[0041] In one embodiment, the shape of the inner ring of the optoelectronic confinement layer is a regular polygon, and the projection of the shape of the non-ion-implanted region of the inclined column far from the active layer on the surface of the second mirror layer in the optoelectronic confinement layer is the inscribed circle of the inner ring of the optoelectronic confinement layer.

[0042] As an example, refer to Figure 3 and Figure 4 . When the projected shape of the optoelectronic confinement pattern OA on the substrate is a regular hexagon, the distribution of the non-ion-implanted region A1 and the ion-implanted region A2 on the side of the second mirror layer far from the active layer is as shown in Figure 3 . The ion-implanted region A2 at least includes the remaining region after inscribing a circle in the regular polygon. That is, the ion-implanted region A2 is the case of the light blue filled region in Figure 3 , and the non-ion-implanted region is the region inside the circle; the distribution of the non-ion-implanted region A1 and the ion-implanted region A2 on the side of the second mirror layer close to the active layer is as shown in Figure 4 . The above ion-implanted region is the region outside the circle after deviating the circle in Figure 3 , and the non-ion-implanted region is the region inside the circle; thus, in the entire second mirror layer, the non-ion-implanted region is an inclined cylindrical region. It can be seen in Figure 4In [the above], the non-ion implantation region A1 of the inclined cylinder does not coincide with the three inner angles of the inner ring of the optical confinement layer, thus destroying the current concentration region at the inner angle tips of the traditional laser. Therefore, in this non-ion implantation region of the inclined cylinder, the shortest current path is no longer the region where the inner angle tips of the optical confinement layer are located.

[0043] As an example, the ion implantation region A2 is obtained by performing ion implantation on the resonant cavity structure under the shielding of a mask pattern IMP, and the projected shape of the mask pattern IMP on the substrate St is the circumcircle of the optical confinement pattern OA. In one of the embodiments, refer to Figure 2 ; the second mirror layer further includes a C-shaped contact metal pad, and the opening of the C-shaped contact metal pad faces the first inner angle, and the first inner angle is one of the inner angles of the inner ring of the optical confinement layer in the region where the non-ion implantation region of the inclined cylinder intersects with the optical confinement layer. In addition, the inclination direction of the non-ion implantation region A1 of the above-mentioned inclined cylinder is opposite to the opening direction of the above-mentioned C-shaped contact metal pad.

[0044] In one of the embodiments, the inclination angle of the non-ion implantation region of the inclined cylinder with respect to the vertical direction of the upper surface of the second mirror layer is 2° - 7°. For example, the inclination angle of the non-ion implantation region of the inclined cylinder with respect to the vertical direction of the upper surface of the second mirror layer can be 3°, 5°, 6° or 7°.

[0045] In a second aspect, please refer to Figure 6 , the present application further provides a method for manufacturing a surface-emitting laser, including steps S10 - S40: Step S10, providing an epitaxial layer; wherein, the epitaxial layer includes a substrate and a first mirror layer, an active region and a second mirror layer disposed on the substrate; Step S20, performing mesa etching on the epitaxial layer to obtain a plurality of trenches, and the trenches expose a part of the surface of the first mirror layer; Step S30, performing a wet oxidation process on the epitaxial layer through the trenches to form an optical confinement layer in the second mirror layer; wherein, the optical confinement layer is a polygonal ring structure, and the inner ring of the optical confinement layer includes at least three inner angles; Step S40, applying a mask pattern on the surface of the epitaxial layer, and performing an ion implantation process on the epitaxial layer through the mask pattern to form a non-ion implantation region of an inclined cylinder in the second mirror layer, and the non-ion implantation region A1 of the inclined cylinder does not coincide with at least one of the at least three inner angles of the inner ring of the optical confinement layer; wherein, the region outside the non-ion implantation region of the inclined cylinder is the ion implantation region.

[0046] In one embodiment, in the step of performing an ion implantation process on the epitaxial layer through the mask pattern, the angle of the ion implantation is inclined by 2°-7° with respect to the vertical direction of the upper surface of the second mirror layer.

[0047] Specifically, as Figure 5 shown, the above mask is a circular mask, and the projection of the above mask on the above substrate is the circumcircle of the projection of the inner ring of the optical confinement layer on the substrate. Additionally, when performing an ion implantation process on the epitaxial layer through the mask pattern, the direction of the ion implantation deviates from the vertical direction of the plane where the substrate is located. And the range of the included angle α between the direction of the ion implantation and the vertical direction of the plane where the substrate is located is 2°-7°.

[0048] Specifically, the complete preparation method in this specific embodiment can generally include steps such as epitaxial growth, oxidation trench etching, wet oxidation, deep trench etching, deep trench ion implantation, and conductive part fabrication; among them, epitaxial growth, MESA trench etching, wet oxidation, deep trench etching, and deep trench ion implantation can all be understood with reference to the existing processes of surface-emitting lasers, and there is no special improvement in these steps in this embodiment. The key improvement of this application lies in the ion implantation step after wet oxidation.

[0049] Exemplarily, when performing oxidation trench etching, inductively coupled plasma etching technology can be used, the etching gas is a Cl2 / BCl3 mixed gas, and the etching depth is controlled within 5-8 microns, so that the oxidation trench just exposes the second of the first mirror layer 10. A wet oxidation process is performed on the epitaxial layer through the trench 10 to obtain an optical confinement pattern OA. The wet oxidation can be carried out 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 from the sidewall of the oxidation trench inward, and finally forms an optical confinement pattern OA with an irregular geometric shape or a regular polygon.

[0050] Furthermore, hydrogen ions can be used for ion implantation, the implantation energy is 80 keV, and the implantation dose is 3×10 14 cm -2 . The mask pattern can use a photoresist material (PR) with a thickness between 2-3 microns.

[0051] In one embodiment, the trench is an irregular polygon or a regular polygon connected end to end.

[0052] When the projected shape of the optoelectronic confinement pattern OA on the substrate St is an irregular geometric shape, the irregular geometric shape can be a hexagon, pentagon, spindle shape, water droplet shape, concave quadrilateral, diamond shape, etc.; when the projected shape of the optoelectronic confinement pattern OA on the substrate St is a regular polygon, the regular polygon can be an equilateral triangle, square, rectangle, regular pentagon, regular hexagon, regular heptagon, regular octagon, etc. It can be understood that whether it is an irregular geometric shape or a regular polygon, there will basically be corner points in the pattern, that is, the intersection points of two adjacent sides. The corner point position is a place where current is likely to concentrate, that is, the current concentration region described in this application. When a forward bias or reverse bias is applied to the device, a voltage breakdown phenomenon is more likely to occur in the current concentration region, which is not conducive to the overall life and reliability of the device. Further, the current concentration region at least covers the corner point position of the irregular geometric shape; or the current concentration region at least covers the corner point position of the regular polygon. That is to say, the current concentration region at least includes the focus position of the optoelectronic confinement pattern OA.

[0053] In one embodiment, before the mesa etching of the epitaxial layer, the method further includes: forming a C-shaped contact metal pad on the second mirror layer.

[0054] The present invention has at least the following beneficial effects: In the surface-emitting laser provided by the present invention, the ion implantation region A2 is configured as a non-conductive region or a passivated current concentration region. The lattice structure of this region is damaged by ion bombardment, thereby increasing the resistivity and reducing the current passing through this region, so as to form a non-ion implantation region in the shape of an inclined cylinder in the region of the second mirror layer except the ion implantation region; the current concentration situation of the corresponding optoelectronic confinement layer is destroyed, and the reverse breakdown voltage resistance ability of the device is improved.

[0055] It should be understood that although Figure 6 the steps in the flowchart of Figure 6 are shown in sequence according to the indication of the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover,

[0056] In a third aspect, the present application provides a VCSEL chip, including at least one laser array; the laser array includes a plurality of surface-emitting lasers as described above; the laser array is a regularly arranged array, or a randomly arranged array, or an array having a plurality of addressable sub-arrays. Based on the foregoing surface-emitting lasers, the VCSEL chip of this embodiment has good performance in terms of reliability.

[0057] In a fourth aspect, the present application provides a light source for a lidar system, including at least one surface-emitting laser as described above or at least one VCSEL chip as described above.

[0058] In a fifth aspect, the present application provides a lidar system, including a transmitting component and a receiving component, and the transmitting component uses the light source for a lidar system as described above.

[0059] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0060] The above-described embodiments only represent several implementation manners of the embodiments of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the embodiments of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the embodiments of the present application. Therefore, the protection scope of the patent of the embodiments of the present application should be subject to the appended claims.

Claims

1. A surface-emitting laser, characterized in that, It includes a substrate and a resonant cavity structure disposed on the substrate; The resonant cavity structure includes a first mirror layer, an active layer, and a second mirror layer that are sequentially located on the substrate; An optical power confinement layer is formed in the second mirror layer. The optical power confinement layer is a polygon ring structure, and the inner ring of the optical power confinement layer includes at least three interior angles; And The second mirror layer further includes a non-ion implanted region of inclined columns, and the non-ion implanted region of the inclined columns does not coincide with at least one of the at least three interior angles of the inner ring of the optical power confinement layer; In the second mirror layer, the region outside the non-ion implanted region of the inclined columns is an ion implanted region.

2. The surface emitting laser according to claim 1, characterized in that, The shape of the inner ring of the optical power confinement layer includes an irregular polygon or a regular polygon; The region where the non-ion implanted region of the inclined columns intersects the optical power confinement layer does not include at least one interior angle of the inner ring of the optical power confinement layer.

3. The surface emitting laser according to claim 2, wherein, A C-shaped contact metal pad is further included on the second mirror layer, and the opening of the C-shaped contact metal pad faces the first interior angle. The first interior angle is an interior angle of the inner ring of the optical power confinement layer in the region where the non-ion implanted region of the inclined columns intersects the optical power confinement layer.

4. The surface emitting laser according to claim 2, wherein, The shape of the non-ion implanted region of the inclined columns far from the active layer on the surface of the second mirror layer does not include any interior angles of the inner ring of the optical power confinement layer in the projection region on the optical power confinement layer.

5. The surface-emitting laser according to claim 4, characterized in that, The shape of the inner ring of the optical power confinement layer is a regular polygon, and the projection of the shape of the non-ion implanted region of the inclined columns far from the active layer on the surface of the second mirror layer on the optical power confinement layer is an inscribed circle of the inner ring of the optical power confinement layer.

6. The surface-emitting laser according to any one of claims 1 to 5, characterized in that, The inclination angle of the columns of the non-ion implanted region of the inclined columns relative to the vertical direction of the upper surface of the second mirror layer is 2°-7°.

7. A method for manufacturing a surface-emitting laser, characterized in that, It includes: Providing an epitaxial layer; wherein, the epitaxial layer includes a substrate and a first mirror layer, an active region, and a second mirror layer that are sequentially disposed on the substrate; Performing mesa etching on the epitaxial layer to obtain a plurality of trenches, and a part of the surface of the first mirror layer is exposed by the trenches; Performing a wet oxidation process on the epitaxial layer through the trenches to form an optical power confinement layer in the second mirror layer; wherein, the optical power confinement layer is a polygon ring structure, and the inner ring of the optical power confinement layer includes at least three interior angles; Applying a mask pattern on the surface of the epitaxial layer, and performing an ion implantation process on the epitaxial layer through the mask pattern to form a non-ion implanted region of inclined columns in the second mirror layer; Wherein, the region outside the non-ion implanted region of the inclined columns is an ion implanted region.

8. The manufacturing method of the surface emitting laser according to claim 7, characterized in that, The trenches are irregular polygons or regular polygons connected end to end.

9. The manufacturing method of the surface-emitting laser according to claim 8, characterized in that, Before performing the mesa etching on the epitaxial layer, the method further includes: forming a C-shaped contact metal pad on the second mirror layer.

10. The method for manufacturing a surface-emitting laser according to claim 9, characterized in that, In the step of performing the ion implantation process on the epitaxial layer through the mask pattern, the angle of the ion implantation is inclined 2°-7° relative to the vertical direction of the upper surface of the second mirror layer.

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