A vertical-cavity surface-emitting laser for high-speed communication and its fabrication method.

Abstract

This invention provides a vertical-cavity surface-emitting laser (VCSEL) for high-speed communication and its fabrication method. The VCSEL comprises an epitaxial wafer, an oxide layer, an electrically insulating region, a dielectric layer, and P and N metal layers. The VCSEL structure satisfies the following: 1. The epitaxial wafer includes a resonant cavity with a total thickness of 1 / 2 optical wavelength. The oxide layer is formed on the active region of the resonant cavity. 2. The electrically insulating region is formed by ion implantation and extends from top to bottom below the active region of the resonant cavity. 3. The relief structure described in the above embodiment is set near the output aperture. The combination of these three structural characteristics enables a single-mode VCSEL for high-speed modulation. By etching the relief structure on the surface of the output aperture, the dielectric and non-dielectric regions spaced apart provide different overall reflectivities, enabling filtering of higher-order modes, thereby forming a single-mode output.

Description

Technical Field

[0001] This invention relates to the field of semiconductor chip technology, and in particular to a vertical cavity surface-emitting laser for high-speed communication and its fabrication method. Background Technology

[0002] VCSEL (Vertical-Cavity Surface-Emitting Laser) is an abbreviation for vertical-cavity surface-emitting laser. Since its initial concept was proposed in 1977 by Kenichi Iga and others at the Tokyo Institute of Technology, it has undergone over forty years of technological development and innovation. Due to its numerous significant advantages, including low threshold voltage, small far-field divergence angle, high modulation rate, ease of implementation of single-mode operation, and superior two-dimensional integration, VCSEL has demonstrated broad application prospects and practical value in various fields such as broadband Ethernet, high-speed data communication, optical interconnects, three-dimensional sensing, and optical integrated components.

[0003] Compared to edge-emitting semiconductor lasers, VCSELs have long been used as multimode lasers due to their shorter resonant cavity and larger emission surface. The shorter resonant cavity results in a larger longitudinal mode spacing within the FP cavity, typically allowing only one longitudinal mode to emit light. The larger emission surface allows for more transverse modes to be emitted, thus creating multiple transverse modes. The term "multimode" generally refers to multiple transverse modes.

[0004] Single-mode lasers are needed in certain specialized fields, such as providing a better signal-to-noise ratio in sensing and reducing bit errors caused by transmission dispersion in long-distance data transmission. Therefore, single-mode VCSELs have been one of the many directions for VCSEL evolution. Traditionally, single-mode VCSELs can be obtained by reducing the diameter of the emitting region to below 3-4 micrometers; however, this significantly reduces the output power of the device. The rapid increase in resistance caused by an excessively small aperture is detrimental to high-frequency modulation, and the small aperture also poses a significant challenge to mass production.

[0005] To reduce the number of transverse modes, the cavity length of the VCSEL resonator can be increased. A longer cavity increases the losses encountered by each mode during resonance formation, while the base film experiences the least loss and wins in mode competition, thus achieving single-mode output. However, in high-speed data communication VCSELs, an excessively long cavity increases photon lifetime, significantly limiting the device's frequency bandwidth and modulation rate. Using a shorter cavity can increase the rate; however, with normal fabrication processes, this results in multimodes, which is detrimental to long-distance transmission. Summary of the Invention

[0006] The purpose of this invention is to provide a vertical-cavity surface-emitting laser (VCSEL) for high-speed communication and its fabrication method. The VCSEL provided in this invention, through simultaneous improvements in epitaxy and fabrication processes, forms a single-mode output VCSEL device suitable for high-speed communication, which is beneficial for expanding the application of VCSELs in the field of data communication. The VCSEL provided in this invention can be used as the emission source for high-speed optical modules of 400G / 800G / 1.6T. Furthermore, compared to traditional short-distance data communication with a transmission distance of less than 500 meters, the VCSEL provided in this invention can be used for high-speed optical interconnects of 500-2000 meters and above.

[0007] In a first aspect, the present invention provides a vertical-cavity surface-emitting laser (VCSEL) for high-speed communication. The VCSEL for high-speed communication includes:

[0008] An epitaxial wafer, comprising: a substrate, an N-type Bragg mirror, a resonant cavity, an active region formed in the resonant cavity, and a P-type Bragg mirror arranged sequentially from bottom to top;

[0009] An oxide layer formed on the active region in the resonant cavity;

[0010] An electrically insulating region is formed after ion implantation, extending from top to bottom below the active region in the resonant cavity;

[0011] A dielectric layer formed on the epitaxial wafer; and,

[0012] A P-metal layer formed on the epitaxial wafer;

[0013] The total thickness of the resonant cavity is 1 / 2 times the optical wavelength;

[0014] The vertical cavity surface-emitting laser further includes an exit aperture, which is formed on the P-type Bragg mirror, and the diameter of the exit aperture is larger than the diameter of the oxide hole.

[0015] The light-emitting aperture is provided with an embossed structure, which is formed by partially etching the surface of the dielectric layer. The embossed structure has a non-dielectric region and a dielectric region.

[0016] The medium region includes: a first medium region, a second medium region, and a third medium region;

[0017] The non-dielectric region includes: a first non-dielectric region and a second non-dielectric region;

[0018] A first non-dielectric region is disposed between the first dielectric region and the second dielectric region; a second non-dielectric region is disposed between the second dielectric region and the third dielectric region;

[0019] The first dielectric region is a solid circle, and the straight line connecting the center of the first dielectric region and the center of the oxide hole is perpendicular to the extending plane where the substrate is located; the diameter of the first dielectric region is smaller than the diameter of the oxide hole;

[0020] The second dielectric region is annular, and the center of both the inner and outer circles of the second dielectric region coincides with the center of the first dielectric region; the annular width of the second dielectric region is the first width;

[0021] The third medium region is annular, and the center of both the inner and outer circles of the third medium region coincides with the center of the first medium region; the ring width of the third medium region is the second width;

[0022] The first width is greater than the second width;

[0023] The diameter of the first medium region is greater than the first width.

[0024] Furthermore, both the first non-dielectric region and the second non-dielectric region are annular;

[0025] The ring width of the first non-dielectric region is the third width;

[0026] The ring width of the second non-dielectric region is the fourth width;

[0027] The third width is greater than the fourth width.

[0028] Furthermore, the diameter of the oxide pores is 6 micrometers to 10 micrometers.

[0029] Furthermore, the diameter of the oxide pore is 7 micrometers, and the diameter of the first dielectric region is 5 micrometers;

[0030] The first width is 3 micrometers, and the second width is 2 micrometers.

[0031] Furthermore, the material of the dielectric region is silicon nitride.

[0032] Furthermore, the electrically insulating region extends downwards from the P-type Bragg mirror into the resonant cavity, with the implantation depth reaching below the active region. The electrically insulating region is used to limit the current injected into the vertical cavity surface-emitting laser through the P-surface to the central region, which is the area where the oxide aperture and the light-emitting aperture are located.

[0033] In a second aspect, the present invention provides a method for fabricating a vertical-cavity surface-emitting laser (VCSEL) for high-speed communication, the method comprising:

[0034] S1, forming an epitaxial wafer on a wafer, the epitaxial wafer comprising: a substrate, an N-type Bragg mirror, a resonant cavity, an active region formed in the resonant cavity, and a P-type Bragg mirror arranged sequentially from bottom to top; wherein, the total thickness of the resonant cavity is 1 / 2 times the optical wavelength;

[0035] S2, After the epitaxial wafer growth is completed, a P-metal layer is deposited;

[0036] S3, a dielectric layer is deposited using plasma-enhanced chemical vapor deposition, the dielectric layer being used to protect the P metal layer and the epitaxial wafer;

[0037] S4, a deep pit is formed using inductively coupled plasma-reactive ion etching, which exposes the sidewalls that need to be wet-oxidized;

[0038] S5, an oxide layer is formed above the active region by wet oxidation, the oxide layer including oxide holes with a diameter of D0; in the resonant cavity, the epitaxial material above the active region is Al. x Ga 1-x As material, where x = 0.98 to 0.99, 6 micrometers ≤ D0 ≤ 10 micrometers;

[0039] S6. After using photoresist to protect the light-emitting area and part of the metal contact area, ion implantation is performed to form an electrically insulating region. The electrically insulating region is formed from top to bottom in the epitaxial wafer down to below the active region in the resonant cavity.

[0040] S7, a medium layer is deposited on the sidewall of the deep pit using plasma-enhanced chemical vapor deposition;

[0041] S8, define the light-emitting aperture of the vertical cavity surface-emitting laser in the dielectric layer, and define the etching pattern of the relief structure by photolithography, and further etch the dielectric layer at the light-emitting aperture to form the relief structure;

[0042] Wherein, the diameter of the light-emitting hole is larger than the diameter of the oxide hole; the relief structure has a non-medium region and a medium region;

[0043] The medium region includes: a first medium region, a second medium region, and a third medium region;

[0044] The non-dielectric region includes: a first non-dielectric region and a second non-dielectric region;

[0045] A first non-dielectric region is disposed between the first dielectric region and the second dielectric region; a second non-dielectric region is disposed between the second dielectric region and the third dielectric region;

[0046] The first dielectric region is a solid circle, and the straight line formed by connecting the center of the first dielectric region and the center of the oxidation hole is perpendicular to the extended plane where the substrate is located; the diameter of the first dielectric region is smaller than the diameter of the oxidation hole;

[0047] The second dielectric region is an annulus, and the centers of both the inner circle and the outer circle of the second dielectric region coincide with the center of the first dielectric region; the ring width of the second dielectric region is the first width;

[0048] The third dielectric region is an annulus, and the centers of both the inner circle and the outer circle of the third dielectric region coincide with the center of the first dielectric region; the ring width of the third dielectric region is the second width;

[0049] The first width is greater than the second width;

[0050] The diameter of the first dielectric region is greater than the first width;

[0051] S9. Fabricate the N metal layer and perform dicing to form multiple vertical cavity surface emitting lasers.

[0052] Further, in S6, the types and doses of the ion implantation include:

[0053] H+ ions with an implantation energy of 410 keV and a dose of 5E+13, H+ ions with an implantation energy of 360 keV and a dose of 4E+13, H+ ions with an implantation energy of 300 keV and a dose of 3.5E+14, H+ ions with an implantation energy of 230 keV and a dose of 3.5E+14, H+ ions with an implantation energy of 100 keV and a dose of 4E+14, and H+ ions with an implantation energy of 20 keV and a dose of 4E+14.

[0054] Further, in S1, the steps of forming the epitaxial wafer include:

[0055] S11. Grow an N-type Bragg reflector on the N-type substrate by using metalorganic chemical vapor deposition or molecular beam epitaxy, which includes an Al x Ga (1-x) As material with alternating growth of high refractive index materials and low refractive index materials, where in the high refractive index material, x = x1 and 0.05 < x1 < 0.2, and in the low refractive index material, x = x2 and 0.8 < x2 < 0.95, and the thickness of each layer of Al x Ga (1-x) As material is one-quarter of the optical thickness;

[0056] S12. Form the resonant cavity on the surface of the N-type Bragg reflector, and the resonant cavity includes an AlGaAs bulk material with a gradually changing aluminum component;

[0057] S13. After forming a resonator cavity with a thickness greater than 1 μm, deposit the active region, which includes multiple sets of strained quantum wells containing InGaAs and AlGaAs and is used to generate the gain required for laser. The active region is formed at the 1 / 2 position in the resonator cavity. After the deposition of the active region is completed, further grow the remaining thickness of the resonator cavity.

[0058] S14. Form a P-type Bragg reflector above the resonator cavity to complete the growth of the epitaxial wafer. The P-type Bragg reflector includes an AlGaAs material with alternating growth of high refractive index materials and low refractive index materials. Among them, in the high refractive index material, y = y1 and 0.05 < y1 < 0.2, and in the low refractive index material, y = y2 and 0.8 < y2 < 0.9. The thickness of each layer of AlGaAs material is one-fourth of the optical thickness. y Ga (1-y) As material, where, in the high refractive index material, y = y1 and 0.05 < y1 < 0.2, and in the low refractive index material, y = y2 and 0.8 < y2 < 0.9. The thickness of each layer of AlGa y Ga (1-y) As material is one-fourth of the optical thickness.

[0059] Further, after forming the electrically insulating region in S6, the steps of S9 include:

[0060] S91. Fabricate a polymer material layer, and after the fabrication of the polymer material layer is completed, further deposit a dielectric layer for protecting the surface and sidewalls by plasma-enhanced chemical vapor deposition. The polymer material layer is located below the P metal layer.

[0061] S92. Open a hole on the P side and perform gold plating on the front to form a gold electrode on the P metal layer.

[0062] S***93. Etch the N-side step, evaporate an alloy material to form a front N metal layer, and after the fabrication of the front N metal layer is completed, further deposit a dielectric layer for protecting the surface and sidewalls by plasma-enhanced chemical vapor deposition.

[0063] S94. Thin the surface of the substrate away from the N-type Bragg reflector, and further perform backside alloy evaporation to form a back N metal layer.

[0064] S95. Split the wafer to form multiple vertical cavity surface emitting lasers with different output optical powers.

[0065] The present invention has at least the following advantages or beneficial effects:

[0066] 1. In the resonator cavity of the vertical cavity surface emitting laser for high-speed communication, by using a resonator cavity with a total thickness of 1 / 2 times the optical wavelength, reducing the photon lifetime and increasing the response bandwidth of the vertical cavity surface emitting laser by shortening the resonator cavity to 1 / 2 times the optical wavelength, the rate is thus improved.

[0067] 2. The electrically insulating region of this invention is formed using ion implantation. Formed from top to bottom below the active region of the resonant cavity, the electrically insulating region effectively limits the current injection diameter, thereby reducing the excitation of higher-order modes. Furthermore, the size of the electrically insulating region also affects the current injection into the vertical-cavity surface-emitting laser (VCSEL) used for high-speed communication. The electrically insulating region is used to confine the current injected into the VCSEL through the P-surface to a central region, which is the area where the oxide aperture and the light-emitting aperture are located. Confining the current injected into the VCSEL through the P-surface to a central region maximizes the spatial overlap between the current and the LP01 fundamental mode, thus reducing the excitation of higher-order modes.

[0068] 3. This invention uses an etched relief structure on the surface of the light-emitting aperture to filter higher-order modes, thereby forming a single-mode output. The relief structure includes spaced-apart dielectric and non-dielectric regions that provide different overall reflectivities, enabling mode selection. Specifically, the dielectric region includes a first dielectric region located in the center of the light-emitting aperture. This first dielectric region provides optimal reflectivity and has a high degree of overlap with the fundamental mode output light of the vertical-cavity laser used for high-speed communication, thus effectively exciting the fundamental mode light.

[0069] 4. The main structural features of this invention include: 1. The epitaxial wafer includes a resonant cavity with a total thickness of 1 / 2 optical wavelength. An oxide layer is formed on the active region of the resonant cavity; 2. The electrically insulating region is formed by ion implantation, and the electrically insulating region is formed from top to bottom below the active region of the resonant cavity; 3. The relief structure described in the above embodiment is provided near the light exit aperture; The combination of the above three structural features enables a single-mode vertical-cavity surface laser for high-speed modulation.

[0070] 5. This invention also provides a method for fabricating a vertical-cavity surface-mount laser (VCSEL) for high-speed communication. The VCSEL for high-speed communication has the following three structural characteristics: 1. An epitaxial wafer includes a resonant cavity with a total thickness of 1 / 2 optical wavelength. An oxide layer is formed on the active region of the resonant cavity; 2. An electrically insulating region is formed by ion implantation, and the electrically insulating region is formed from top to bottom below the active region of the resonant cavity; 3. A relief structure as described in the above embodiment is set near the output aperture. The combination of these three structural characteristics enables a single-mode VCSEL for high-speed modulation. Experiments have shown that using the special relief structure in the technical solution of this invention, combined with a shortened resonant cavity and assisted ion implantation, is necessary to realize a single-mode VCSEL for high-speed modulation. Specifically, by etching a relief structure on the surface of the output aperture, the dielectric and non-dielectric regions spaced apart provide different overall reflectivities, achieving filtering of higher-order modes, thereby forming a single-mode output.

[0071] The vertical-cavity surface-emitting laser (VCSEL) for high-speed communication developed in this invention can be used as the emission source for high-speed optical modules of 400G / 800G / 1.6T. Furthermore, compared to traditional short-distance data communication with a transmission distance of less than 500 meters, the VCSEL for high-speed communication provided by this invention can be used for high-speed optical interconnects of 500-2000 meters or more. Attached Figure Description

[0072] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0073] Figure 1 A schematic diagram of a vertical-cavity surface-emitting laser for high-speed communication provided in an embodiment of the present invention;

[0074] Figure 2 A top view schematic diagram of the relief structure of a vertical cavity surface-emitting laser for high-speed communication provided in an embodiment of the present invention;

[0075] Figure 3 A comparison chart of the performance test results of a vertical-cavity surface-emitting laser for high-speed communication provided in an embodiment of the present invention and devices in the prior art;

[0076] Figure 4 The image shows the spectral test results of a vertical-cavity surface-emitting laser in the prior art.

[0077] Figure 5 The image shows the spectral test results of a vertical cavity surface-emitting laser for high-speed communication provided in an embodiment of the present invention.

[0078] Icon Description

[0079] Vertical-cavity surface-emitting laser 100 for high-speed communication:

[0080] Epitaxial wafer 110: substrate 10, N-type Bragg mirror 20, resonant cavity 30, active region 31, P-type Bragg mirror 40;

[0081] Oxide layer 50, electrically insulating region 60, dielectric layer 70, polymer material layer 80;

[0082] Relief structure 90:

[0083] Medium region 91: First medium region 91a, second medium region 91b, third medium region 91c;

[0084] Non-dielectric region 92: First non-dielectric region 92a, second non-dielectric region 92b;

[0085] P-metal layer 120; front N-metal layer 131; back N-metal layer 132. Detailed Implementation

[0086] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0087] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0088] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0089] Please see Figure 1 This invention provides a vertical-cavity surface-emitting laser 100 for high-speed communication, which can be used as an optical module for high-speed communication. The vertical-cavity surface-emitting laser 100 for high-speed communication includes: an epitaxial wafer 110, an oxide layer 50, an electrically insulating region 60, a dielectric layer 70, a polymer material layer 80, a P-metal layer 120, a front N-metal layer 131, and a back N-metal layer 132. The vertical-cavity surface-emitting laser 100 for high-speed communication also includes an embossed structure 90. In one embodiment, the specific structure of the embossed structure 90 is as follows... Figure 2 As shown. Figure 2 The diagram shows a top view near the exit aperture of a vertical cavity surface-emitting laser 100 used for high-speed communication.

[0090] In this embodiment, the oxide layer 50 is formed on the active region 31 of the resonant cavity 30. The electrically insulating region 60 is formed by ion implantation. The electrically insulating region 60 is formed from top to bottom below the active region 31 of the resonant cavity 30, effectively limiting the current injection diameter and thus reducing the excitation of higher-order modes. Furthermore, the size of the electrically insulating region 60 also affects the current injection of the vertical-cavity surface-emitting laser (VCSEL) used for high-speed communication. In this embodiment, the electrically insulating region 60 is used to confine the current injected into the VCSEL 100 through the P-surface to the central region, which is the area where the oxide aperture and the light-emitting aperture are located. Confining the current injected into the VCSEL 100 through the P-surface to the central region results in the highest overlap between the current and the LP01 fundamental mode space, thus reducing the excitation of higher-order modes.

[0091] A dielectric layer 70 is formed on the epitaxial wafer 110, such as on the top surface of the P-type Bragg mirror 40, the side surfaces of some structural layers of the epitaxial wafer 110, or a portion of the surface of the substrate 10. The material of the dielectric layer 70 can be silicon nitride, silicon carbide, or silicon dioxide. A P-metal layer 120 is formed on the epitaxial wafer 110, and the P-metal layer 120 may further include a p-type contact metal and a gold plating layer. The P-metal layer 120 serves as the P-electrode of a vertical-cavity surface-emitting laser used for high-speed communication.

[0092] The total thickness of the resonant cavity 30 is 1 / 2 optical wavelength. A typical VCSEL device contains a resonant cavity with a thickness of 1 optical wavelength. In this invention, the resonant cavity 30 with a total thickness of 1 / 2 optical wavelength is used. By shortening the resonant cavity 30 to 1 / 2 optical wavelength, the photon lifetime is reduced, the response bandwidth of the vertical wall laser is increased, and thus the speed is improved.

[0093] The vertical-cavity surface-mount laser 100 for high-speed communication also includes light-emitting apertures disposed between spaced P-type metal layers 120. The light-emitting apertures are formed on a P-type Bragg mirror 40, such as... Figure 1 The diameter of the light-emitting aperture is larger than the diameter of the oxide aperture.

[0094] The light-emitting aperture is provided with an embossed structure 90, which is formed through the surface of a portion of the etching medium layer. For details, please refer to [reference needed]. Figure 2 The relief structure 90 has a medium region 91 and a non-medium region 92. The medium region 91 includes a first medium region 91a, a second medium region 91b, and a third medium region 91c. The non-medium region 92 includes a first non-medium region 92a and a second non-medium region 92b.

[0095] A first non-dielectric region 92a is disposed between the first dielectric region 91a and the second dielectric region 91b. A second non-dielectric region 92b is disposed between the second dielectric region 91b and the third dielectric region 91c. The first dielectric region 91a is a solid circle, and the straight line connecting the center of the first dielectric region 91a and the center of the oxide hole is perpendicular to the extending plane of the substrate. The diameter D1 of the first dielectric region 91a is smaller than the diameter D0 of the oxide hole. The second dielectric region 91b is annular, and the center of both the inner and outer circles of the second dielectric region 91b coincides with the center of the first dielectric region 91a. The annular width of the second dielectric region 91b is a first width, which is obtained by subtracting the inner diameter D21 of the outer circle diameter D22 of the second dielectric region 91b. The third dielectric region 91c is annular, and the center of both the inner and outer circles of the third dielectric region 91c coincides with the center of the first dielectric region 91a. The annular width of the third dielectric region 91c is a second width. The second width is obtained by subtracting the inner diameter D31 of the third medium region 91c from the outer diameter D32 of the third medium region 91c.

[0096] The first width is greater than the second width. The diameter of the first dielectric region 91a is greater than the first width.

[0097] In this embodiment, an embossed structure 90 is etched onto the surface of the light-emitting aperture to filter higher-order modes, thereby forming a single-mode output. The embossed structure 90 includes dielectric regions 91 and non-dielectric regions 92 spaced apart from each other, providing different overall reflectivities to achieve mode selection. Specifically, the dielectric region 91 includes a first dielectric region 91a located in the center of the light-emitting aperture. The first dielectric region 91a can provide optimal reflectivity, and the first dielectric region 91a has a high degree of overlap with the fundamental mode output light of the vertical-cavity laser 100 used for high-speed communication, which can effectively excite the fundamental mode light.

[0098] The first non-dielectric region 92a between the first dielectric region 91a and the second dielectric region 91b, and the second non-dielectric region 92b between the second dielectric region 91b and the third dielectric region 91c, both have low reflectivity. The lasing beams of the second-higher-order modes LP11 / LP12 / LP21 and higher-order modes are mainly distributed outside the first dielectric region 91a, and will encounter significant losses in the first and second non-dielectric regions 92a and 92b, which have low reflectivity. Therefore, they attenuate in the mode competition within the laser cavity, and ultimately only the fundamental mode can achieve lasing. The diameter of the first dielectric region 91a is larger than its first width, and the first width is larger than its second width. This design allows for better promotion of the fundamental mode's lasing and better suppression of the second-higher-order and higher-order modes' lasing, while simultaneously satisfying the aforementioned structural design in the substructures of the dielectric region 91a and the non-dielectric region 92a.

[0099] In this embodiment of the invention, 1. the epitaxial wafer includes a resonant cavity with a total thickness of 1 / 2 optical wavelength. An oxide layer is formed on the active region of the resonant cavity; 2. the electrically insulating region is formed by ion implantation, and the electrically insulating region is formed from top to bottom below the active region of the resonant cavity; 3. the relief structure 90 of the above embodiment is provided near the light exit aperture; the combination of the above three methods can realize a single-mode vertical cavity surface laser for high-speed modulation.

[0100] Some existing technologies incorporate detailed structures near the output aperture, but these technologies primarily improve the divergence angle and are mainly used in 3D sensing. This invention aims to achieve a single-mode vertical-cavity surface-mount laser for high-speed modulation, which cannot be achieved simply by incorporating detailed structures near the output aperture (although the device may have a small divergence angle, the speed is low). Therefore, the special relief structure 90 in this invention, combined with a shortened resonant cavity and assisted ion implantation, is necessary to realize a single-mode vertical-cavity surface-mount laser for high-speed modulation.

[0101] In this embodiment of the invention, by etching a specific surface relief structure 90 on the light-emitting surface of a vertical-cavity surface-mount laser 100 used for high-speed communication, the loss of higher-order modes can be increased, promoting the lasing of the fundamental mode. The relief structure 90 involved in this embodiment relatively reduces the specular reflectivity of higher-order modes located near the first non-dielectric region 92a and the second non-dielectric region 92b. By introducing the relief structure 90, the threshold gain of higher-order modes can be improved. In contrast, the base film is not sensitive to the low reflectivity of the first non-dielectric region 92a and the second non-dielectric region 92b introduced by the relief structure 90, while the light from the second-highest and higher-order modes is sensitive to the low reflectivity of the first non-dielectric region 92a and the second non-dielectric region 92b introduced by the relief structure 90, thereby achieving mode selection and obtaining the fundamental mode output. In other words, since the fundamental mode is mainly located in the center (first dielectric region 91a), and the fundamental mode does not coincide with the first non-dielectric region 92a and the second non-dielectric region 92b, the fundamental mode is less affected by the relief structure 90. In the non-central part (non-first dielectric region 91a), the light field of the higher-order mode largely overlaps with the first non-dielectric region 92a and the second non-dielectric region 92b. Therefore, the light of the higher-order mode is greatly affected by the relief structure 90, resulting in significant attenuation, and the higher-order mode cannot be excited.

[0102] In one embodiment, both the first non-dielectric region 92a and the second non-dielectric region 92b are annular. The annular width of the first non-dielectric region 92a is a third width. The annular width of the second non-dielectric region 92b is a fourth width. The third width is greater than the fourth width.

[0103] In this embodiment, the specific structural configuration of the first non-dielectric region 92a and the second non-dielectric region 92b can better suppress the lasing of the second-highest order mode and the higher-order mode, so that only the fundamental mode can obtain lasing in the vertical cavity surface emitter laser 100 used for high-speed communication.

[0104] In one embodiment, the diameter of the oxide pores in the oxide layer 50 is between 6 micrometers and 10 micrometers. The light field passes through the oxide pores. The diameter of the position from the base film to the surface relief structure 90 is about 4 micrometers to 7 micrometers. The diameter of higher-order modes will be larger, possibly reaching 8 micrometers to 11 micrometers. The relief structure 90 is set in this invention to provide different overall reflectivity, thereby realizing mode selection.

[0105] In one embodiment, the diameter D0 of the oxide pore can be set to 7 micrometers. In another embodiment, the diameter D0 of the oxide pore can be set to 8 micrometers. In yet another embodiment, the diameter D0 of the oxide pore can be set to 9 micrometers. In still another embodiment, the diameter D0 of the oxide pore can be set to 10 micrometers.

[0106] In one embodiment, the diameter of the oxide hole is 7 micrometers, and the diameter of the first dielectric region 91a is 5 micrometers. The first width is 3 micrometers, and the second width is 2 micrometers. The diameter D1 of the first dielectric region 91a (e.g., 5 micrometers) is smaller than the diameter D0 of the oxide hole (e.g., 7 micrometers). The second dielectric region 91b is annular, with both the inner and outer circles of the second dielectric region 91b coinciding with the center of the first dielectric region 91a. The annular width of the second dielectric region 91b is the first width. The first width is obtained by subtracting the inner diameter D21 (e.g., 8 micrometers) of the outer diameter D22 (e.g., 11 micrometers) of the second dielectric region 91b. The third dielectric region 91c is annular, with both the inner and outer circles of the third dielectric region 91c coinciding with the center of the first dielectric region 91a. The annular width of the third dielectric region 91c is the second width. The second width is obtained by subtracting the inner diameter D31 (e.g., 13 micrometers) of the outer diameter D32 (e.g., 15 micrometers) of the third dielectric region 91c. The area beyond the center of the first dielectric region 91a, with a diameter of 12 μm, is the ion implantation region, i.e., the electrically insulating region 60.

[0107] In one embodiment, the dielectric layer 70 is made of silicon nitride.

[0108] In one embodiment, the electrically insulating region 60 extends downwards from the P-type Bragg mirror 40 into the resonant cavity 30, with the implantation depth reaching below the active region 31. The electrically insulating region 60 serves to confine the current injected through the P-surface into the vertical-cavity surface-emitting laser 100 used for high-speed communication to a central region, which is the area containing the oxide aperture and the light-emitting aperture. The central region includes a stacked structure disposed between the back N-metal layer 132 and the P-metal layer 120, encompassing the area containing the oxide aperture and the light-emitting aperture.

[0109] In this embodiment, the electrically insulating region 60 is used to confine the current injected into the vertical-cavity surface-emitting laser 100 through the P-surface to a central region, which is the area where the oxide aperture and the light-emitting aperture are located. Confining the current injected into the vertical-cavity surface-emitting laser 100 through the P-surface to the central region results in the highest degree of overlap between the current and the LP01 fundamental mode in space, which can reduce the excitation of higher-order modes.

[0110] In one embodiment, the active region 31 is located at the 1 / 2 position in the resonant cavity 30, which facilitates photolasing.

[0111] In another aspect of the present invention, a method for fabricating a vertical-cavity surface-emitting laser 100 for high-speed communication includes:

[0112] S1, an epitaxial wafer 110 is formed on a wafer. The epitaxial wafer 110 includes, from bottom to top, a substrate 10, an N-type Bragg mirror 20, a resonant cavity 30, an active region 31 formed in the resonant cavity 30, and a P-type Bragg mirror 40. The total thickness of the resonant cavity 30 is 1 / 2 times the optical wavelength.

[0113] In this step, a resonant cavity with a total thickness of 1 / 2 optical wavelength is set. By shortening the resonant cavity 30 to 1 / 2 optical wavelength, the photon lifetime is reduced, the response bandwidth of the vertical wall laser is increased, and thus the rate is improved.

[0114] S2, after the epitaxial wafer 110 is grown, a P metal layer 120 is deposited. The material of the P metal layer 120 can be Ti / Pt / Au.

[0115] S3, a dielectric layer 70 is deposited using plasma-enhanced chemical vapor deposition (PECVD). The dielectric layer 70 can be made of silicon nitride. The dielectric layer 70 is used to protect the P metal layer 120 and the epitaxial wafer 110.

[0116] S4 uses inductively coupled plasma-reactive ion etching (ICP-RIE etching) to create deep pits, which expose the sidewalls that will be wet-oxidized. These pits are then used for wet oxidation in subsequent steps.

[0117] S5, High-temperature steam is introduced into the wet oxidation furnace and wet oxidation is performed through the sidewall of the deep pit: an oxide layer 50 is formed above the active region 31 by wet oxidation. The oxide layer 50 includes oxide holes with a diameter of D0. In the resonant cavity 30, the epitaxial material above the active region 31 is Al. x Ga 1-x As material, where x = 0.98 to 0.99, 6 micrometers ≤ D0 ≤ 10 micrometers.

[0118] S6. After protecting the light-emitting area and part of the metal contact area with photoresist, ion implantation is performed to form an electrically insulating region 60. The electrically insulating region 60 is formed from top to bottom in the epitaxial wafer 110, extending below the active region 31 in the resonant cavity 30. The ion implantation region is the electrically insulating region 60, which provides a better current-limiting area and helps suppress higher-order modes.

[0119] S7. A dielectric layer 70 is deposited on the sidewall of the deep pit using plasma-enhanced chemical vapor deposition. The dielectric layer 70 can be made of silicon nitride to protect the sidewall.

[0120] S8, the exit aperture of the vertical cavity surface-emitting laser is defined in the dielectric layer 70, and the etching pattern of the relief structure 90 is defined by photolithography. The dielectric layer 70 at the exit aperture is further etched to form the relief structure 90. The relief structure 90 includes a dielectric region 91 and a non-dielectric region 92. The dielectric region 91 includes a first dielectric region 91a, a second dielectric region 91b, and a third dielectric region 91c spaced apart. The non-dielectric region 92 includes a first non-dielectric region 92a and a second non-dielectric region 92b spaced apart.

[0121] A first non-dielectric region 92a is disposed between the first dielectric region 91a and the second dielectric region 91b. A second non-dielectric region 92b is disposed between the second dielectric region 91b and the third dielectric region 91c. The first dielectric region 91a is a solid circle, and the straight line connecting the center of the first dielectric region 91a and the center of the oxide hole is perpendicular to the extending plane of the substrate. The diameter D1 of the first dielectric region 91a is smaller than the diameter D0 of the oxide hole. The second dielectric region 91b is annular, and the center of both the inner and outer circles of the second dielectric region 91b coincides with the center of the first dielectric region 91a. The annular width of the second dielectric region 91b is a first width, which is obtained by subtracting the inner diameter D21 of the outer circle diameter D22 of the second dielectric region 91b. The third dielectric region 91c is annular, and the center of both the inner and outer circles of the third dielectric region 91c coincides with the center of the first dielectric region 91a. The annular width of the third dielectric region 91c is a second width. The second width is obtained by subtracting the inner diameter D31 of the third medium region 91c from the outer diameter D32 of the third medium region 91c.

[0122] The first width is greater than the second width. The diameter of the first dielectric region 91a is greater than the first width.

[0123] S9, fabricating an N metal layer, and cleaving it to form multiple vertical cavity surface-emitting lasers 100 for high-speed communication.

[0124] This embodiment provides a method for fabricating a vertical-cavity surface-mount laser 100 for high-speed communication. The vertical-cavity surface-mount laser 100 for high-speed communication has the following three structural characteristics: 1. An epitaxial wafer includes a resonant cavity with a total thickness of 1 / 2 optical wavelength. An oxide layer is formed on the active region of the resonant cavity; 2. An electrically insulating region is formed by ion implantation, and the electrically insulating region is formed from top to bottom below the active region of the resonant cavity; 3. An embossed structure 90 as described in the above embodiment is set near the light-emitting aperture. The combination of the above three structural characteristics can realize a single-mode vertical-cavity surface-mount laser for high-speed modulation. Experiments have shown that the special embossed structure 90 in the technical solution of this invention, combined with a shortened resonant cavity and assisted ion implantation, can realize a single-mode vertical-cavity surface-mount laser for high-speed modulation. In this embodiment, the embossed structure 90 is etched on the surface of the light-emitting aperture. The dielectric region 91 and non-dielectric region 92 arranged at intervals provide different overall reflectivities, thereby filtering higher-order modes and forming a single-mode output.

[0125] In one embodiment, in S6, the type and dosage of ion implantation include:

[0126] The H+ ions were injected with an energy of 410 keV and a dose of 5E+13, an energy of 360 keV and a dose of 4E+13, an energy of 300 keV and a dose of 3.5E+14, an energy of 230 keV and a dose of 3.5E+14, an energy of 100 keV and a dose of 4E+14, and an energy of 20 keV and a dose of 4E+14.

[0127] In this embodiment, the use of specific types and dosages of ion implantation helps to form an electrically insulating region extending below the active region of the resonant cavity. This electrically insulating region is used to confine the current injected into the vertical-cavity surface-emitting laser 100 through the P-face to a central region, which is the area containing the oxide aperture and the light-emitting aperture. Confining the current injected into the vertical-cavity surface-emitting laser 100 through the P-face to the central region ensures the highest spatial overlap between the current and the LP01 fundamental mode, thereby reducing the excitation of higher-order modes.

[0128] In one embodiment, step S1 of forming the epitaxial wafer 110 includes:

[0129] S11. On the N-type substrate 10, grow an N-type Bragg reflector 20 by metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE), which includes Al x Ga (1-x) As materials with alternating growth of high refractive index materials and low refractive index materials. Among them, in the high refractive index material, x = x1, and 0.05 < x1 < 0.2 is satisfied; in the low refractive index material, x = x2, and 0.8 < x2 < 0.95 is satisfied. The thickness of each layer of Al x Ga (1-x) As material is one-quarter of the optical thickness.

[0130] S12. Form a resonant cavity 30 on the surface of the N-type Bragg reflector 20. The resonant cavity 30 includes an AlGaAs bulk material with a gradually changing aluminum composition. The resonant cavity 30 is used to filter light of high-order modes. The resonant cavity 30 is beneficial to form a single-mode device. The active region 31 is located in the upper-middle position of the resonant cavity 30. The thickness of the resonant cavity 30 above the active region 31 is thinner, and the thickness of the resonant cavity 30 below the active region 31 is thicker.

[0131] S13. After the resonant cavity 30 is formed to a thickness greater than 1 μm, deposit the active region 31. The active region 31 includes multiple groups of strained quantum wells containing InGaAs and AlGaAs, which are used to generate the gain required for laser. The active region 31 is formed at the 1 / 2 position in the resonant cavity 30. After the deposition of the active region 31 is completed, further grow the remaining thickness of the resonant cavity 30.

[0132] S14. Form a P-type Bragg reflector 40 (P-DBR) above the resonant cavity 30 to complete the growth of the epitaxial wafer 110. Among them, the P-type Bragg reflector 40 includes Al y Ga (1-y) As materials with alternating growth of high refractive index materials and low refractive index materials. Among them, in the high refractive index material, y = y1, and 0.05 < y1 < 0.2 is satisfied; in the low refractive index material, y = y2, and 0.8 < y2 < 0.9 is satisfied. The thickness of each layer of Al y Ga (1-y) As material is one-quarter of the optical thickness.

[0133] In this embodiment, a method for preparing the epitaxial wafer 110 is provided. The epitaxial wafer 110 with good properties is more helpful for the formation of the vertical cavity surface emitting laser 100 used for high-speed communication.

[0134] In one embodiment, after forming the electrically insulating region 60 in S6, the steps of S9 include:

[0135] S91, fabrication of polymer material layer 80, and after the polymer material layer 80 is fabricated, further deposition of dielectric layer 70 for protecting the surface and sidewalls using ion-enhanced chemical vapor deposition. Polymer material layer 80 is located below P-metal layer 120. The material of polymer material layer 80 is benzocyclobutene (BCB), with the molecular formula C8H8. BCB is a novel reactive resin that can form both thermoplastic and thermosetting polymers. Polymer material layer 80 has a low dielectric constant and dielectric loss, which helps reduce device capacitance.

[0136] S92, make a hole on the P side and perform gold plating on the front side to form a gold electrode on the P metal layer 120.

[0137] S93, etch the N-side steps, evaporate the Ge / Au alloy material to form the front N metal layer 131, and after the front N metal layer 131 is fabricated, use ion-enhanced chemical vapor deposition to further deposit a dielectric layer 70 for protecting the surface and sidewalls.

[0138] S94, the surface of the substrate 10 away from the N-type Bragg mirror 20 is thinned, and a back alloy evaporation is further performed to form a back N metal layer 132.

[0139] S95, the wafer is cleaved to form multiple vertical-cavity surface-emitting lasers 100 with different output optical powers for high-speed communication. This completes all processes, forming... Figure 1 The vertical cavity surface-emitting laser 100 shown is used for high-speed communication.

[0140] In one specific embodiment, a vertical-cavity surface laser for high-speed communication, having a shortened resonant cavity, special ion implantation, and a special relief structure 90, is fabricated using the fabrication method described in any of the preceding embodiments. The specific structure of the relief structure 90 is as follows: the diameter of the oxide hole is 7 micrometers. The first dielectric region 91a (central portion) of the relief structure 90 is circular with a diameter of 5 micrometers. The inner and outer diameters of the second dielectric region 91b (the outermost first layer structure) of the relief structure 90 are 8 micrometers and 11 micrometers, respectively. The inner and outer diameters of the third dielectric region 91c (the outermost second layer structure) of the relief structure 90 are 13 micrometers and 15 micrometers, respectively.

[0141] The central part of the relief structure 90, namely the first dielectric region 91a, provides the best reflectivity. The fundamental mode LP01 has a radius of approximately 7.5 micrometers, and its main energy is concentrated in the center, which highly overlaps with the central part of the relief structure 90 (first dielectric region 91a). Therefore, the fundamental mode LP01 can be well excited. However, the main light intensity distribution of the second-higher-order modes LP11 / LP12 / LP21 and higher-order modes is outside the radius of 5 micrometers. They will encounter the low reflectivity region (first non-dielectric region 92a and second non-dielectric region 92b) between the first dielectric region 91a, the second dielectric region 91b, and the third dielectric region 91c, resulting in greater losses. Therefore, they attenuate in the mode competition of the laser cavity, and ultimately only the fundamental mode can achieve lasing.

[0142] Specific effects are as follows Figure 3 and Figure 5 As shown. Figure 3 As shown, due to the use of the shortened resonant cavity, special ion implantation, and relief structure 90 in the above embodiments of the present invention, the laser modulation frequency (3dB bandwidth of parameter S21) is increased from 16.2GHz bandwidth of conventional devices to 20.1GHz.

[0143] like Figure 4 and Figure 5 As shown, due to the use of the shortened resonant cavity, special ion implantation, and relief structure 90 in the above embodiments of the present invention, the spectrum of the device, as observed from the spectrum, is significantly improved compared to conventional devices. Figure 4 As shown, the multimode has become the device in this invention. Figure 5 () Single-mode output.

[0144] The vertical-cavity surface-emitting laser (VCSEL) for high-speed communication developed in this invention can be used as the emission source for high-speed optical modules of 400G / 800G / 1.6T. Furthermore, compared to traditional short-distance data communication with a transmission distance of less than 500 meters, the VCSEL for high-speed communication provided by this invention can be used for high-speed optical interconnects of 500-2000 meters or more.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vertical-cavity surface-emitting laser for high-speed communication, characterized in that, include: An epitaxial wafer, comprising: a substrate, an N-type Bragg mirror, a resonant cavity, an active region formed in the resonant cavity, and a P-type Bragg mirror arranged sequentially from bottom to top; An oxide layer formed on the active region in the resonant cavity; the oxide layer includes oxide pores; An electrically insulating region is formed after ion implantation, extending from top to bottom below the active region in the resonant cavity; A dielectric layer formed on the epitaxial wafer; and, A P-metal layer formed on the epitaxial wafer; The total thickness of the resonant cavity is 1 / 2 times the optical wavelength; The vertical cavity surface-emitting laser further includes an exit aperture, which is formed on the P-type Bragg mirror, and the diameter of the exit aperture is larger than the diameter of the oxide hole. The light-emitting aperture is provided with an embossed structure, which is formed by partially etching the surface of the dielectric layer. The embossed structure has a non-dielectric region and a dielectric region. The medium region includes: a first medium region, a second medium region, and a third medium region; The non-dielectric region includes: a first non-dielectric region and a second non-dielectric region; A first non-dielectric region is disposed between the first dielectric region and the second dielectric region; a second non-dielectric region is disposed between the second dielectric region and the third dielectric region; The first dielectric region is a solid circle, and the straight line connecting the center of the first dielectric region and the center of the oxide hole is perpendicular to the extending plane where the substrate is located; the diameter of the first dielectric region is smaller than the diameter of the oxide hole; The second dielectric region is annular, and the center of both the inner and outer circles of the second dielectric region coincides with the center of the first dielectric region; the annular width of the second dielectric region is the first width; The third medium region is annular, and the center of both the inner and outer circles of the third medium region coincides with the center of the first medium region; the ring width of the third medium region is the second width; The first width is greater than the second width; The diameter of the first medium region is greater than the first width.

2. The vertical-cavity surface-emitting laser for high-speed communication according to claim 1, characterized in that, Both the first non-dielectric region and the second non-dielectric region are annular; The ring width of the first non-dielectric region is the third width; The ring width of the second non-dielectric region is the fourth width; The third width is greater than the fourth width.

3. The vertical-cavity surface-emitting laser for high-speed communication according to claim 2, characterized in that, The diameter of the oxide pores is 6-10 micrometers.

4. The vertical-cavity surface-emitting laser for high-speed communication according to claim 3, characterized in that, The diameter of the oxide pore is 7 micrometers, and the diameter of the first dielectric region is 5 micrometers; The first width is 3 micrometers, and the second width is 2 micrometers.

5. The vertical-cavity surface-emitting laser for high-speed communication according to any one of claims 1-4, characterized in that, The material of the dielectric region is silicon nitride.

6. The vertical-cavity surface-emitting laser for high-speed communication according to claim 5, characterized in that, The electrically insulating region extends downwards from the P-type Bragg mirror into the resonant cavity, with the implantation depth reaching below the active region. The electrically insulating region is used to limit the current injected into the vertical cavity surface-emitting laser through the P-surface to the central region, which is the area where the oxide aperture and the light-emitting aperture are located.

7. A method for fabricating a vertical-cavity surface-emitting laser for high-speed communication, characterized in that, include: S1, forming an epitaxial wafer on a wafer, the epitaxial wafer comprising: a substrate, an N-type Bragg mirror, a resonant cavity, an active region formed in the resonant cavity, and a P-type Bragg mirror arranged sequentially from bottom to top; wherein, the total thickness of the resonant cavity is 1 / 2 times the optical wavelength; S2, After the epitaxial wafer growth is completed, a P-metal layer is deposited; S3, a dielectric layer is deposited using plasma-enhanced chemical vapor deposition, the dielectric layer being used to protect the P metal layer and the epitaxial wafer; S4, a deep pit is formed using inductively coupled plasma-reactive ion etching, which exposes the sidewalls that need to be wet-oxidized; S5, an oxide layer is formed above the active region by wet oxidation, the oxide layer including oxide holes with a diameter of D0; in the resonant cavity, the epitaxial material above the active region is Al. x Ga 1-x As material, where x = 0.98~0.99, 6 micrometers ≤ D0 ≤ 10 micrometers; S6. After using photoresist to protect the light-emitting area and part of the metal contact area, ion implantation is performed to form an electrically insulating region. The electrically insulating region is formed from top to bottom in the epitaxial wafer down to below the active region in the resonant cavity. S7, a medium layer is deposited on the sidewall of the deep pit using plasma-enhanced chemical vapor deposition; S8, define the light-emitting aperture of the vertical cavity surface-emitting laser in the dielectric layer, and define the etching pattern of the relief structure by photolithography, and further etch the dielectric layer at the light-emitting aperture to form the relief structure; Wherein, the diameter of the light-emitting hole is larger than the diameter of the oxide hole; the relief structure has a non-medium region and a medium region; The medium region includes: a first medium region, a second medium region, and a third medium region; The non-dielectric region includes: a first non-dielectric region and a second non-dielectric region; A first non-dielectric region is disposed between the first dielectric region and the second dielectric region; a second non-dielectric region is disposed between the second dielectric region and the third dielectric region; The first dielectric region is a solid circle, and the straight line connecting the center of the first dielectric region and the center of the oxide hole is perpendicular to the extending plane where the substrate is located; the diameter of the first dielectric region is smaller than the diameter of the oxide hole; The second dielectric region is annular, and the center of both the inner and outer circles of the second dielectric region coincides with the center of the first dielectric region; the annular width of the second dielectric region is the first width; The third medium region is annular, and the center of both the inner and outer circles of the third medium region coincides with the center of the first medium region; the ring width of the third medium region is the second width; The first width is greater than the second width; The diameter of the first dielectric region is greater than the first width; S9 is used to fabricate an N-metal layer and cleave it to form multiple vertical cavity surface-emitting lasers.

8. The method for fabricating a vertical-cavity surface-emitting laser for high-speed communication according to claim 7, characterized in that, In S6, the type and dosage of ion implantation include: The H+ ions were injected with an energy of 410 keV and a dose of 5E+13, an energy of 360 keV and a dose of 4E+13, an energy of 300 keV and a dose of 3.5E+14, an energy of 230 keV and a dose of 3.5E+14, an energy of 100 keV and a dose of 4E+14, and an energy of 20 keV and a dose of 4E+14.

9. The method for fabricating a vertical-cavity surface-emitting laser for high-speed communication according to claim 7, characterized in that, In S1, the step of forming the epitaxial wafer includes: S11. Grow an N-type Bragg reflector on an N-type substrate by metalorganic chemical vapor deposition or molecular beam epitaxy, which includes AlGaAs materials with alternating growth of high refractive index materials and low refractive index materials. Among them, in the high refractive index materials, x = x1, and 0.05 < x1 < 0.2 is satisfied. In the low refractive index materials, x = x2, and 0.8 < x2 < 0.95 is satisfied. The thickness of each layer of AlGaAs material is one-fourth of the optical thickness. x Ga (1-x) As materials, where in the high refractive index materials, x = x1, and 0.05 < x1 < 0.2 is satisfied, and in the low refractive index materials, x = x2, and 0.8 < x2 < 0.95 is satisfied. The thickness of each layer of Al x Ga (1-x) As material is one-fourth of the optical thickness; S12, the resonant cavity is formed on the surface of the N-type Bragg mirror, the resonant cavity comprising a bulk AlGaAs material with a graded aluminum composition; S13, after the resonant cavity is formed to a thickness greater than 1 micrometer, the active region is deposited, the active region comprising multiple sets of strained quantum wells containing InGaAs and AlGaAs for generating the gain required for laser irradiation, the active region being formed at a position of 1 / 2 in the resonant cavity; after the active region is deposited, the remaining thickness of the resonant cavity is further grown; S14. A P-type Bragg reflector is formed above the resonant cavity to complete the growth of the epitaxial wafer. The P-type Bragg reflector includes Al y Ga (1-y) As materials that grow alternately with high refractive index materials and low refractive index materials. In the high refractive index materials, y = y1, and 0.05 < y1 < 0.2 is satisfied. In the low refractive index materials, y = y2, and 0.8 < y2 < 0.9 is satisfied. The thickness of each layer of Al y Ga (1-y) As material is one-quarter of the optical thickness.

10. The method for fabricating a vertical-cavity surface-emitting laser for high-speed communication according to claim 7, characterized in that, After the electrically insulating region is formed in S6, step S9 includes: S91, fabricating a polymer material layer, and after the polymer material layer is fabricated, further depositing a dielectric layer for protecting the surface and sidewalls using ion-enhanced chemical vapor deposition; the polymer material layer is located below the P metal layer; S92, make a hole on the P side and perform gold plating on the front side to form a gold electrode on the P metal layer; S93, etch N-side steps, evaporate alloy material to form front N metal layer, and after the front N metal layer is fabricated, use ion-enhanced chemical vapor deposition to further deposit a dielectric layer for protecting the surface and sidewalls. S94, the surface of the substrate away from the N-type Bragg mirror is thinned, and a back alloy evaporation is further performed to form a back N metal layer; S95, the wafer is cleaved to form multiple vertical cavity surface-emitting lasers with different output optical powers.

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