A vertical cavity surface emitting laser

Abstract

The utility model relates to a laser technology field especially relates to a vertical cavity surface emitting laser, and vertical cavity surface emitting laser includes: the substrate layer, N type DBR structure, first interval layer, active layer, second interval layer and P type DBR structure that stack in proper order, wherein, the P type DBR structure is by high refractive index P type semiconductor layer and low refractive index P type semiconductor layer alternately arranged multiple periods constitute, the low refractive index P type semiconductor layer is the P type semiconductor layer containing Al component, a layer low refractive index P type semiconductor layer in the P type DBR structure adjacent the second interval layer is as first oxidation restriction layer, and the mole fraction of Al component in first oxidation restriction layer before oxidation is greater than 0.98, the utility model is at least favorable to the single transverse mode output characteristic of vertical cavity surface emitting laser under high power.

Description

Technical Field

[0001] This invention belongs to the field of laser technology, and particularly relates to a vertical cavity surface-emitting laser. Background Technology

[0002] Vertical-cavity surface-emitting semiconductor lasers (VCSELs) differ from traditional edge-emitting semiconductor lasers. The epitaxial structure of a VCSEL mainly includes an upper Bragg mirror, a lower Bragg mirror, a conductive confinement region, an active region, and a semiconductor substrate. Feedback from the upper and lower Bragg mirrors causes the laser beam to exit the cavity perpendicular to the substrate. VCSELs offer numerous advantages, including low threshold current, circular spot size, high modulation bandwidth, single-mode lasing, ease of fabrication of high-density two-dimensional arrays, and relatively low manufacturing cost. VCSELs have wide applications in many fields, such as optical switches, optical storage, all-optical information conversion, 3D sensing, laser printing, laser displays, laser lighting, automotive electronics, laser processing, consumer electronics, atomic sensing, and lidar.

[0003] The Bragg reflector of a VCSEL is formed by alternating dozens of cycles of two materials with significant band differences. Due to the low single-photon gain of VCSELs, the top or bottom DBR (distributed Bragg reflector) structure needs to achieve sufficiently high reflectivity to enable lasing at low current. Generally, the top DBR structure requires 22-25 cycles, and the bottom DBR structure requires 32-40 cycles. This results in a relatively high series resistance (approximately 80-100Ω) in the VCSEL structure itself, leading to severe chip heating and reduced device performance. Furthermore, due to the large transverse width of VCSELs, the devices typically perform multi-transverse mode lasing, resulting in poor coherence of the output laser and a large divergence angle. Additionally, since VCSELs are generally cylindrical waveguides, their polarization mode stability is relatively poor. To achieve lasing characteristics of the fundamental transverse mode in VCSELs, a common method is to fabricate a small current injection aperture (≤3μm) to suppress higher-order transverse modes. If a smaller current-limiting aperture is used to achieve single-mode lasing, this will further increase the overall series resistance of the VCSEL, increasing heat generation, power consumption, and reducing conversion efficiency. Simultaneously, high resistance leads to increased chip operating temperature, which is detrimental to overall chip reliability and reduces its lifespan.

[0004] Therefore, how to achieve both fundamental transverse mode optical characteristics and low electrical resistance in VCSELs through reliable and effective design schemes is a technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the present invention aims to provide a vertical cavity surface-emitting laser, which at least helps to improve the single transverse mode output characteristics of the vertical cavity surface-emitting laser at high power.

[0006] To achieve the above objectives, the technical solution of this utility model is implemented as follows: This invention provides a vertical cavity surface-emitting laser, comprising: a substrate layer, an N-type DBR structure, a first spacer layer, an active layer, a second spacer layer, and a P-type DBR structure stacked sequentially; wherein, the P-type DBR structure is composed of multiple cycles of alternating high-refractive-index P-type semiconductor layers and low-refractive-index P-type semiconductor layers, the low-refractive-index P-type semiconductor layers being P-type semiconductor layers containing Al composition; the first low-refractive-index P-type semiconductor layer adjacent to the second spacer layer in the P-type DBR structure serves as a first oxide confinement layer, and the molar fraction of Al composition in the first oxide confinement layer before oxidation is greater than 0.98.

[0007] Furthermore, in the P-type DBR structure, apart from the first low-refractive-index P-type semiconductor layer adjacent to the second spacer layer, the molar fraction of Al component in the remaining low-refractive-index P-type semiconductor layer is in the range of 0.9 to 0.93.

[0008] Furthermore, the first oxidation confinement layer includes a first oxidized portion and a first non-oxidized portion, with the first oxidized portion surrounding the first non-oxidized portion.

[0009] Furthermore, the high-refractive-index P-type semiconductor layer is a P-type low-aluminum AlGaAs material, in which the molar fraction of Al component is in the range of 0 to 0.1, and the low-refractive-index P-type semiconductor layer is a P-type high-aluminum AlGaAs material.

[0010] Furthermore, the N-type DBR structure is composed of multiple alternating periods of high-refractive-index N-type semiconductor layers and low-refractive-index N-type semiconductor layers. In the N-type DBR structure, the first low-refractive-index N-type semiconductor layer adjacent to the first spacer layer serves as the second oxide confinement layer. The molar fraction of Al component in the second oxide confinement layer before oxidation is greater than 0.98. In the N-type DBR structure, except for the first low-refractive-index N-type semiconductor layer adjacent to the first spacer layer, the molar fraction of Al component in the remaining low-refractive-index N-type semiconductor layers is in the range of 0.9 to 0.93.

[0011] Furthermore, the second oxidation confinement layer includes a second oxidized portion and a second non-oxidized portion, with the second oxidized portion surrounding the second non-oxidized portion.

[0012] Furthermore, the high-refractive-index N-type semiconductor layer is an N-type low-aluminum AlGaAs material, in which the molar fraction of Al component is in the range of 0 to 0.1, and the low-refractive-index N-type semiconductor layer is an N-type high-aluminum AlGaAs material.

[0013] Furthermore, the second spacer layer comprises a stacked first portion and a second doped portion, the second doped portion being located between the first portion and the P-type DBR structure, and the doping concentration of the second doped portion being greater than that of the first portion, with the doping concentration of the second doped portion being 1×10⁻⁶. 18 cm -3 ~5×10 18 cm -3 Within the range.

[0014] Furthermore, the vertical cavity surface-emitting laser also includes an N-type contact electrode and a P-type contact electrode. The N-type contact electrode is located on the bottom surface of the substrate away from the N-type DBR structure, and the P-type contact electrode is located on the top surface of the P-type DBR structure away from the second spacer layer.

[0015] Compared with the prior art, the present invention can achieve the following beneficial effects: The vertical cavity surface-emitting laser provided by the present invention, on the one hand, designs the mole fraction of the low refractive index P-type semiconductor layer in the first cycle near the resonant cavity in the P-type DBR structure of the device to be greater than 0.98, and uses this low refractive index P-type semiconductor layer with a mole fraction greater than 0.98 as the first oxide confinement layer, so that the first oxide confinement layer is located near the peak of the strong light intensity distribution in the resonant cavity, thereby achieving a strong effect on the light wave in the cavity. Specifically, in terms of electricity, it achieves the confinement of the current path; in terms of optics, it achieves the filtering of higher-order modes. After oxidation, the refractive index of the low refractive index P-type semiconductor layer is reduced from 3 to about 1.7. Within the resonant cavity, the light waves interacting with the oxidized region will have a reduced resonant wavelength compared to the unoxidized region due to the decrease in optical thickness. This results in a difference in resonant wavelengths between the two regions. Furthermore, after oxidation, the optical thickness of the first oxide confinement layer no longer meets the requirement of 0.25 times the wavelength, and the reflection loss at the oxide interface is significant. Therefore, the reflectivity of the oxidized portion of the first oxide confinement layer will decrease substantially, significantly increasing the coupling loss between higher-order modes and the oxidized region. When the coupling between higher-order modes and the oxidized region is enhanced, their resonant wavelength decreases compared to the fundamental mode in the unoxidized region, suppressing the material gain of higher-order modes. Moreover, the reflection loss of higher-order modes is greater than that of the fundamental mode, which helps to increase the difference between the fundamental and higher-order modes, thereby achieving stable single-mode output. On the other hand, by increasing the doping concentration of the spacer layer near the P-type DBR structure in the resonant cavity, after the charge carriers pass through the first oxide confinement layer that restricts the current, the highly doped second doped portion in the second spacer layer will cause the charge carriers entering the resonant cavity to expand laterally within a certain range. The lateral expansion of the current is equivalent to increasing the lateral emission width of the active region, thereby increasing the lateral distribution width of each mode in the resonant cavity. Combined with the first oxide confinement layer, this is beneficial to further increase the loss of higher-order modes, thereby achieving stable single-mode output. Attached Figure Description

[0016] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings: Figure 1 This is a schematic diagram of the structure of the vertical cavity surface-emitting laser described in an embodiment of the present invention; Figure 2 This is a schematic diagram of the current path in a vertical-cavity surface-emitting laser. Figure 3 This is a schematic diagram of the mode distribution in a vertical cavity surface-emitting laser. Detailed Implementation

[0017] Analysis revealed the following drawbacks of existing surface-emitting lasers (VCSELs): VCSELs require a small current-limiting aperture to achieve single-mode output, leading to increased resistance, heat generation, and decreased chip power and efficiency, thus failing to achieve high-power single-mode output. Single-mode output of VCSELs can be achieved through surface etching of rings or concave reliefs, which is a commonly used single-mode VCSEL manufacturing method. This method suppresses higher-order modes by introducing a thickness difference of 0.25 wavelengths between the etched and unetched areas. However, this structure requires a specific relationship between the size of the surface relief and the size of the VCSEL oxide aperture to achieve relatively stable single-mode operation. If the difference is too large, the relief will damage the fundamental mode. The high energy consumption of the etching process affects the single-mode output power, threshold, and efficiency. If the difference is too small, the etching will not effectively suppress higher-order modes. As the injection current increases, multimode lasing will occur. The precision of the etching depth in the etching region also directly affects the filtering effect of higher-order modes. If it deviates from 0.25 times the wavelength (about 50nm), the single-mode effect will be affected. Furthermore, the reflectivity of the DBR on the output side of the VCSEL also affects the suppression effect of the etching on multimode. If the reflectivity is high, the etching will not effectively suppress higher-order modes. If the DBR reflectivity is low, the etching will effectively suppress higher-order modes, but the overall specular reflection loss of the chip will increase, and the output efficiency, power, and threshold of the fundamental mode will also deteriorate.

[0018] To address the aforementioned issues, this invention proposes a vertical cavity surface-emitting laser (VCSEL) that can meet single transverse mode output characteristics at high power. Unlike small-aperture single-mode VCSELs, the device structure provided by this invention incorporates a mode filtering structure, which can effectively suppress the lasing of higher-order modes of the VCSEL. The oxide aperture can be made larger, resulting in high power, low resistance, and high efficiency optoelectronic characteristics. Furthermore, it does not require additional etching of micro / nano structures or high-precision processing requirements, simplifying the manufacturing process.

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and do not constitute a limitation thereof.

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0021] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] refer to Figure 1 This invention provides a vertical-cavity surface-emitting laser (VCSEL), comprising: a substrate layer 100, an N-type DBR structure 101, a first spacer layer 102, an active layer 103, a second spacer layer 104, and a P-type DBR structure 105, stacked sequentially. The P-type DBR structure 105 is composed of alternating high-refractive-index P-type semiconductor layers and low-refractive-index P-type semiconductor layers over multiple periods. The low-refractive-index P-type semiconductor layers are P-type semiconductor layers containing Al components. The first low-refractive-index P-type semiconductor layer adjacent to the second spacer layer 104 in the P-type DBR structure 105 serves as a first oxide confinement layer 1051. The molar fraction of Al components in the first oxide confinement layer 1051 before oxidation is greater than 0.98. This improves the coupling strength between higher-order modes and the oxidized region in the first oxide confinement layer 1051.

[0025] Before oxidation, the thickness of each high-refractive-index P-type semiconductor layer is equal to the distance of light traveling a quarter wavelength in that layer, and the thickness of each low-refractive-index P-type semiconductor layer is equal to the distance of light traveling a quarter wavelength in that layer.

[0026] The active layer 103 is an active region composed of multiple quantum well structures. The active layer 103 is used to generate the optical gain required to form a laser. The active layer 103, the first spacer layer 102 and the second spacer layer 104 together constitute the resonant cavity of the vertical cavity surface emitter laser. The first spacer layer 102 and the second spacer layer 104 are used to adjust the cavity length. The band gap of the first spacer layer 102 is larger than the band gap of the quantum well, and the band gap of the second spacer layer 104 is larger than the band gap of the quantum well, so as to form a confinement effect on the charge carriers.

[0027] Furthermore, in the P-type DBR structure 105, apart from the low-refractive-index P-type semiconductor layer adjacent to the second spacer layer 104, the molar fraction of Al component in the remaining low-refractive-index P-type semiconductor layer is in the range of 0.9 to 0.93.

[0028] Furthermore, the first oxide confinement layer 1051 includes a first oxidized portion and a first non-oxidized portion, with the first oxidized portion surrounding the first non-oxidized portion. The first oxidized portion is formed by lateral oxidation of the first low-refractive-index P-type semiconductor layer adjacent to the second spacer layer 104 in the P-type DBR structure 105 using a wet nitrogen oxidation method. The oxidation rate can be controlled by adjusting parameters such as oxidation temperature, water vapor temperature, pressure, and flow rate, and the lateral oxidation depth can be controlled by controlling the time. Ultimately, a first non-oxidized portion with an unoxidized center and a first oxidized portion with an oxidized periphery are formed. The first oxidized portion forms a high-resistance region, and the current injected into the laser will be restricted to only passing through the first non-oxidized portion in the center.

[0029] Furthermore, the high-refractive-index P-type semiconductor layer is a P-type low-aluminum AlGaAs material, in which the molar fraction of Al component is in the range of 0 to 0.1, and the low-refractive-index P-type semiconductor layer is a P-type high-aluminum AlGaAs material.

[0030] Furthermore, the N-type DBR structure 101 is composed of multiple alternating periods of high-refractive-index N-type semiconductor layers and low-refractive-index N-type semiconductor layers. In the N-type DBR structure 101, the first low-refractive-index N-type semiconductor layer adjacent to the first spacer layer 102 serves as the second oxidation confinement layer. The molar fraction of Al component in the second oxidation confinement layer before oxidation is greater than 0.98.

[0031] Furthermore, in the N-type DBR structure 101, apart from the first low-refractive-index N-type semiconductor layer adjacent to the first spacer layer 102, the molar fraction of Al component in the remaining low-refractive-index N-type semiconductor layer is in the range of 0.9 to 0.93.

[0032] Furthermore, the second oxide confinement layer includes a second oxidized portion and a second non-oxidized portion, with the second oxidized portion surrounding the second non-oxidized portion. The second oxidized portion is formed by lateral oxidation of the first low-refractive-index N-type semiconductor layer adjacent to the first spacer layer 102 in the N-type DBR structure 101 using a wet nitrogen oxidation method. The oxidation rate can be controlled by adjusting parameters such as oxidation temperature, water vapor temperature, pressure, and flow rate, and the lateral oxidation depth can be controlled by controlling the time. Ultimately, a second non-oxidized portion with an unoxidized center and a second oxidized portion with an oxidized periphery are formed. The second oxidized portion forms a high-resistance region, and the current injected into the laser will be restricted to passing only through the second non-oxidized portion in the center.

[0033] Furthermore, the high-refractive-index N-type semiconductor layer is an N-type low-aluminum AlGaAs material, in which the molar fraction of Al component is in the range of 0 to 0.1, and the low-refractive-index N-type semiconductor layer is an N-type high-aluminum AlGaAs material.

[0034] Furthermore, the second spacer layer 104 includes a stacked first portion 1041 and a second doped portion 1042. The second doped portion 1042 is located between the first portion 1041 and the p-type DBR structure 105. The doping concentration of the second doped portion 1042 is greater than that of the first portion 1041, and the doping concentration of the second doped portion 1042 is 1×10⁻⁶. 18 cm -3 ~5×10 18 cm -3 Within the specified range, the doping concentration of the first part 1041 is less than 1×10⁻⁶. 18 cm -3 In some embodiments, the first part 1041 may also be left undoped.

[0035] In some embodiments, the thickness of the second doped portion 1042 is in the range of 40 nm to 60 nm, and the material of the second doped portion 1042 can be AlGaAs, with C as the dopant.

[0036] refer to Figure 2 and Figure 3 , Figure 2 The red line in the diagram represents the current path when the second doped portion 1042 is not heavily doped. Figure 2 The blue line in the diagram represents the current path when the second doped portion 1042 is heavily doped. Figure 3The blue lines in the text indicate higher-order modes. Figure 3 The red line represents the fundamental mode, the dashed line represents the mode distribution when the second doped portion 1042 is heavily doped, and the solid line represents the mode distribution when the second doped portion 1042 is not heavily doped. It can be seen that increasing the doping concentration of the spacer layer near the P-type DBR structure 105 in the resonant cavity is beneficial for the carriers entering the resonant cavity to undergo a certain range of lateral expansion. This lateral expansion of the current is equivalent to increasing the lateral emission width of the active region, thereby increasing the lateral distribution width of each mode within the resonant cavity.

[0037] Furthermore, the vertical cavity surface-emitting laser also includes an N-type contact electrode 107 and a P-type contact electrode 106. The N-type contact electrode 107 is located on the bottom surface of the substrate layer 100 away from the N-type DBR structure 101, and the P-type contact electrode 106 is located on the top surface of the P-type DBR structure 105 away from the second spacer layer 104. The P-type contact electrode 106 surrounds the light-emitting aperture.

[0038] In some embodiments, the P-type DBR structure 105 is located on a portion of the surface of the second spacer layer 104 away from the active layer 103. The vertical cavity surface-emitting laser also includes an insulating layer 108, which is located on the remaining surface of the second spacer layer 104 away from the active layer 103. The insulating layer 108 is located on the surface of the P-type DBR structure 105 without the light-emitting aperture and the P-type contact electrode 106.

[0039] In some embodiments, the vertical-cavity surface-emitting laser (VCSEL) is a VCSEL with a center wavelength of 850 nm, and the substrate layer 100 is made of GaAs. The N-type DBR structure 101 is composed of 35-40 alternating periods of high-refractive-index N-type semiconductor layers and low-refractive-index N-type semiconductor layers, and the reflectivity of the N-type DBR structure 101 is >99.9%. The P-type DBR structure 105 is composed of 20-24 alternating periods of high-refractive-index P-type semiconductor layers and low-refractive-index P-type semiconductor layers. The reflectivity of the P-type DBR structure 105 is lower than that of the N-type DBR structure 101, so that light is emitted from the top. The material of the first spacer layer 102 is lattice-matched with the material of the substrate layer 100, and the material of the first spacer layer 102 is AlGaAs. The active layer 103 is composed of multiple alternating periods of quantum well layers and barrier layers, the quantum well layers are made of GaAs, and the barrier layers are made of AlGaAs. x Ga 1-xAs, x=0.2~0.4; the material of the second spacer layer 104 is lattice-matched with the material of the substrate layer 100, the material of the second spacer layer 104 is AlGaAs, and the dopant is C; the total optical thickness of the first spacer layer 102, the active layer 103 and the second spacer layer 104 is half a wavelength that is an integer multiple of 850nm, thereby satisfying the standing wave condition of the laser; the material of the insulating layer 108 can be SiO2 or Si3N4, and the thickness of the insulating layer 108 is in the range of 300nm~500nm; the material of the P-type contact electrode 106 includes Ti, Pt and Au; the material of the N-type contact electrode 107 includes Au, Ge and Ni.

[0040] To address the multi-mode output problem of VCSELs, this invention designs the molar fraction of the low-refractive-index P-type semiconductor layer in the first cycle of the P-type DBR structure 105 near the resonant cavity side to be greater than 0.98, and oxidizes the low-refractive-index P-type semiconductor layer with a molar fraction greater than 0.98 into a first oxide confinement layer 1051. Similarly, the molar fraction of the low-refractive-index N-type semiconductor layer in the first cycle of the N-type DBR structure 101 near the resonant cavity side is designed to be greater than 0.98, and the low-refractive-index N-type semiconductor layer with a molar fraction greater than 0.98 into a second oxide confinement layer 1051. The first oxide confinement layer 1051 and the second oxide confinement layer are located near the peak of the strong light intensity distribution in the resonant cavity, which can have a strong effect on the light wave in the cavity. The oxidized region has a large reflection loss. At the same time, increasing the doping concentration of the second spacer layer 104 near the P-type DBR structure 105 expands the lateral width of the current flowing through the first oxide confinement layer 1051, increases the mode width, and thus increases the coupling strength between the higher-order mode and the oxidized region, increases the loss difference between modes, and increases the loss of the higher-order mode, thereby achieving stable single-mode output. Moreover, the vertical cavity surface-emitting laser provided by this utility model can be realized without complex structure and complex process.

[0041] The vertical cavity surface-emitting laser provided by this invention can be fabricated using the following method, which includes: forming a substrate layer 100, an N-type DBR structure 101, a first spacer layer 102, an active layer 103, a second spacer layer 104, and a P-type DBR structure 105 stacked sequentially. The P-type DBR structure 105 is composed of alternating high-refractive-index P-type semiconductor layers and low-refractive-index P-type semiconductor layers in multiple cycles. The low-refractive-index P-type semiconductor layers are P-type semiconductor layers containing Al components. The molar fraction of Al components in the first low-refractive-index P-type semiconductor layer adjacent to the second spacer layer 104 in the P-type DBR structure 105 is greater than 0.98. The first low-refractive-index P-type semiconductor layer adjacent to the second spacer layer 104 in the P-type DBR structure 105 is oxidized to form a first oxide confinement layer 1051.

[0042] In some embodiments, an N-type DBR structure 101 can be epitaxially grown on a substrate layer 100 using MOCVD. Then, a first spacer layer 102, an active layer 103, a second spacer layer 104, and an initial P-type DBR structure 105 are epitaxially grown sequentially on the N-type DBR structure 101. After the initial P-type DBR structure 105 is formed, the epitaxial growth is complete. Next, photoresist coating, photolithography, development, and dry etching are performed to form the P-type DBR structure. The etching gas for dry etching can be typically Cl2, BCl3, or Ar.

[0043] In some embodiments, after forming the P-type DBR structure 105, a wet nitrogen oxidation device is used to laterally oxidize the first low-refractive-index P-type semiconductor layer adjacent to the second spacer layer 104 in the P-type DBR structure 105 to form a first oxidation confinement layer 1051. The oxidation rate is controlled by adjusting parameters such as oxidation temperature, water vapor temperature, pressure, and flow rate, and the lateral oxidation depth is controlled by controlling the time. Finally, an unoxidized hole region is formed in the center, and the oxidized part forms a high-resistance region. The current injected into the laser will be restricted to only pass through the unoxidized hole region in the center.

[0044] In some embodiments, after forming the first oxide confinement layer 1051, an insulating layer 108 can be deposited on the sample surface using a PECVD device. The sample is then subjected to a second photolithography process, followed by spin coating, photolithography, development, and dry etching to expose the area where the P-type contact electrode 106 and the light-emitting aperture are formed. The etching gas used for dry etching of the insulating layer 108 can be typically CF4 and O2. Subsequently, the sample undergoes a third photolithography process, followed by spin coating, photolithography, and development to form a photoresist layer with a deposition window. Then, the P-type contact electrode 106 is deposited using electron beam evaporation or magnetron sputtering. The deposited sample is then subjected to a stripping process in acetone solution to remove the electrode material at the light-emitting aperture. The substrate is then thinned and polished, and the N-type contact electrode 107 is deposited using electron beam evaporation or magnetron sputtering.

[0045] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this utility model can be achieved, and this is not limited herein.

[0046] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A vertical-cavity surface-emitting laser, characterized in that, include: A substrate layer, an N-type DBR structure, a first spacer layer, an active layer, a second spacer layer, and a P-type DBR structure are stacked sequentially. The P-type DBR structure is composed of multiple alternating periods of high-refractive-index P-type semiconductor layers and low-refractive-index P-type semiconductor layers, wherein the low-refractive-index P-type semiconductor layer is a P-type semiconductor layer containing Al components. In the P-type DBR structure, the first low-refractive-index P-type semiconductor layer adjacent to the second spacer layer serves as the first oxidation confinement layer, and the molar fraction of Al component in the first oxidation confinement layer before oxidation is greater than 0.

98.

2. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, In the P-type DBR structure, except for the first low-refractive-index P-type semiconductor layer adjacent to the second spacer layer, the molar fraction of Al component in the remaining low-refractive-index P-type semiconductor layer is in the range of 0.9 to 0.

93.

3. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The first oxidation confinement layer includes a first oxidized portion and a first non-oxidized portion, wherein the first oxidized portion surrounds the first non-oxidized portion.

4. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The high-refractive-index P-type semiconductor layer is a P-type low-aluminum AlGaAs material, in which the molar fraction of Al component is in the range of 0 to 0.

1. The low-refractive-index P-type semiconductor layer is a P-type high-aluminum AlGaAs material.

5. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The N-type DBR structure is composed of multiple cycles of alternating high-refractive-index N-type semiconductor layers and low-refractive-index N-type semiconductor layers. In the N-type DBR structure, the first low-refractive-index N-type semiconductor layer adjacent to the first spacer layer serves as the second oxidation confinement layer. The molar fraction of Al component in the second oxidation confinement layer before oxidation is greater than 0.

98. In the N-type DBR structure, except for the first low-refractive-index N-type semiconductor layer adjacent to the first spacer layer, the molar fraction of Al component in the remaining low-refractive-index N-type semiconductor layers is in the range of 0.9 to 0.

93.

6. The vertical-cavity surface-emitting laser according to claim 5, characterized in that, The second oxidation confinement layer includes a second oxidized portion and a second non-oxidized portion, wherein the second oxidized portion surrounds the second non-oxidized portion.

7. The vertical-cavity surface-emitting laser according to claim 5, characterized in that, The high-refractive-index N-type semiconductor layer is an N-type AlGaAs material with a low aluminum content, where the molar fraction of Al is in the range of 0 to 0.

1. The low-refractive-index N-type semiconductor layer is an N-type AlGaAs material with a high aluminum content.

8. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The second spacer layer comprises a first portion and a second doped portion stacked together. The second doped portion is located between the first portion and the P-type DBR structure. The doping concentration of the second doped portion is greater than that of the first portion, and the doping concentration of the second doped portion is 1×10⁻⁶. 18 cm -3 ~5×10 18 cm -3 Within the range.

9. The vertical-cavity surface-emitting laser according to claim 1, characterized in that, The vertical cavity surface-emitting laser further includes an N-type contact electrode and a P-type contact electrode. The N-type contact electrode is located on the bottom surface of the substrate layer away from the N-type DBR structure, and the P-type contact electrode is located on the top surface of the P-type DBR structure away from the second spacer layer.

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