High speed, high efficiency, low cost semiconductor optical communication device and method of making same

Abstract

The application provides a high-speed, high-efficiency and low-cost semiconductor optical communication device and a preparation method thereof. The high-speed, high-efficiency and low-cost semiconductor optical communication device comprises a first Bragg reflector, first to Nth active layers arranged in sequence along a first direction on one side of the first Bragg reflector, wherein N is an integer greater than or equal to 2; first to N-1th tunnel junctions, wherein any nth-1th tunnel junction is located between an nth-1th active layer and an nth active layer, n is an integer greater than or equal to 2 and less than or equal to N; first to N-1th current limiting layers arranged along the first direction, wherein any nth-1th current limiting layer is located on the side of the nth-1th tunnel junction along a second direction, and the nth-1th current limiting layer has an overlapping projection on the sidewall of the nth-1th tunnel junction along the second direction; and wherein the second direction is perpendicular to the first direction.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, specifically to a high-speed, high-efficiency, and low-cost semiconductor optical communication device and its fabrication method. Background Technology

[0002] In recent years, with the rapid development of large-scale modeling technology in artificial intelligence, technologies such as Chatgpt have demonstrated enormous application potential and will have broad application scenarios in the future. This has led to a surge in computing power demand, which significantly impacts the future development speed of large-scale modeling technology. Data centers will be a crucial infrastructure for the future AI era. Currently, the most widely used network interconnection technology in data centers is optical communication based on vertical-cavity surface-emitting lasers (VCSELs). Developing semiconductor optical communication devices with higher modulation rates can help improve communication speed and data interaction capabilities in data centers, saving on the layout of semiconductor optical communication devices and thus reducing costs. At the same time, with the large-scale deployment of semiconductor optical communication devices (the computing power support equipment in data centers), energy consumption will become a significant challenge. In a sense, the cost of energy consumption will be a crucial factor determining the operating cost. Besides considering deploying semiconductor optical communication devices in regions or countries with lower energy costs, optimizing the energy consumption of the semiconductor optical communication devices themselves is also a very important issue. This is crucial for cost reduction and achieving green AI development. Therefore, developing ultra-high modulation rate and ultra-high efficiency semiconductor optical communication devices is of great significance and has market demand. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is how to simultaneously improve the modulation rate and efficiency of semiconductor optical communication devices while reducing costs, thereby providing a high-speed, high-efficiency, and low-cost semiconductor optical communication device and its fabrication method.

[0004] This application provides a high-speed, high-efficiency, and low-cost semiconductor optical communication device, comprising: a first Bragg reflector; a first active layer to an Nth active layer arranged sequentially along a first direction on one side of the first Bragg reflector, where N is an integer greater than or equal to 2; a first tunnel junction to an (N-1)th tunnel junction, wherein any (n-1)th tunnel junction is located between the (n-1)th active layer and the nth active layer, where n is an integer greater than or equal to 2 and less than or equal to N; a first current limiting layer to an (N-1)th current limiting layer arranged along the first direction, wherein any (n-1)th current limiting layer is located on the side of the (n-1)th tunnel junction along a second direction, and any (n-1)th current limiting layer has an overlapping projection along the second direction on the sidewall of the (n-1)th tunnel junction; wherein the second direction is perpendicular to the first direction.

[0005] Optionally, any (n-1)th current-limiting layer is a semiconductor current-limiting layer; the doping concentration of any (n-1)th current-limiting layer is much smaller than the doping concentration of the (n-1)th tunnel junction.

[0006] Optionally, any (n-1)th current-limiting layer is an insulating current-limiting layer; wherein, the Al content in any (n-1)th tunnel junction is greater than or equal to 0.9.

[0007] Optionally, any (n-1)th tunnel junction includes a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type; the first conductivity type and the second conductivity type are opposite.

[0008] Optionally, in the direction from the (n-1)th current limiting layer to the (n-1)th tunnel junction, the ratio of the width of any (n-1)th current limiting layer to the width of any (n-1)th tunnel junction is 50% to 80%.

[0009] Optionally, in the direction from the (n-1)th current limiting layer to the (n-1)th tunnel junction, the width of any (n-1)th tunnel junction is 1 micrometer to 20 micrometers.

[0010] Optionally, it also includes: an Nth current limiting layer located on the side of the Nth active layer opposite to the first Bragg reflector; and a second Bragg reflector located on the side of the Nth current limiting layer opposite to the first Bragg reflector.

[0011] Optionally, the Nth current limiting layer includes a light-emitting region and an oxide region surrounding the light-emitting region; the light-emitting region and any (n-1)th tunnel junction are disposed opposite to each other along the first direction, and the oxide region and any (n-1)th current limiting layer are disposed opposite to each other along the first direction.

[0012] Optionally, it further includes: a top tunnel junction located between the Nth active layer and the second Bragg mirror; wherein the Nth current limiting layer is located on the side of the top tunnel junction along the second direction, and the Nth current limiting layer has an overlapping projection along the second direction on the sidewall of the top tunnel junction.

[0013] Optionally, any (n-1)th current-limiting layer surrounds the (n-1)th tunnel junction.

[0014] This application also provides a method for fabricating a high-speed, high-efficiency, and low-cost semiconductor optical communication device, comprising: forming a first active layer to an Nth active layer, a first tunnel junction to an (N-1)th tunnel junction, and a first current limiting layer to an (N-1)th current limiting layer arranged along a first direction on one side of a first Bragg reflector; N is an integer greater than or equal to 2; wherein, any (n-1)th tunnel junction is located between the (n-1)th active layer and the nth active layer; any (n-1)th current limiting layer is located on the side of the (n-1)th tunnel junction along a second direction, and any (n-1)th current limiting layer has an overlapping projection along the second direction on the sidewall of the (n-1)th tunnel junction, where n is an integer greater than or equal to 2 and less than or equal to N; wherein, the second direction is perpendicular to the first direction.

[0015] Optionally, the step of forming an arbitrary (n-1)th tunnel junction and an arbitrary (n-1)th current confinement layer includes: forming an (n-1)th initial tunnel junction on the side of the (n-1)th active layer away from the first Bragg reflector; and oxidizing the edge region of the (n-1)th initial tunnel junction to form the (n-1)th tunnel junction and the (n-1)th current confinement layer.

[0016] Optionally, the steps of forming an arbitrary (n-1)th tunnel junction and an arbitrary (n-1)th current confinement layer include: forming an (n-1)th initial current confinement layer on the side of the (n-1)th active layer away from the first Bragg mirror; forming an opening penetrating the (n-1)th initial current confinement layer in the (n-1)th initial current confinement layer, wherein the initial (n-1)th current confinement layer surrounding the opening forms the (n-1)th current confinement layer; forming the (n-1)th tunnel junction in the opening; wherein the doping concentration of the arbitrary (n-1)th current confinement layer is much smaller than the doping concentration of the (n-1)th tunnel junction.

[0017] Optionally, it further includes: forming an Nth current-limiting layer on the side of the Nth active layer away from the first Bragg reflector; and forming a second Bragg reflector on the side of the Nth current-limiting layer away from the first Bragg reflector.

[0018] Optionally, forming the Nth current limiting layer includes forming a light-emitting region and an oxide region surrounding the light-emitting region; the light-emitting region and any (n-1)th tunnel junction are disposed opposite to each other along the first direction, and the oxide region and any (n-1)th current limiting layer are disposed opposite to each other along the first direction.

[0019] Optionally, it further includes: forming a top-level tunnel junction, the top-level tunnel junction being located between the Nth active layer and the second Bragg reflector; wherein the Nth current-limiting layer is located on the side of the top-level tunnel junction along the second direction, and any Nth current-limiting layer has an overlapping projection along the second direction on the sidewall of the top-level tunnel junction.

[0020] The technical solution of this invention has the following beneficial effects:

[0021] The high-speed, high-efficiency, and low-cost semiconductor optical communication device provided by this invention features an (n-1)th tunnel junction that cascades the (n-1)th active layer and the nth active layer, resulting in greater gain within the cavity and higher power output. Higher power output enables higher-order modulation coding, thereby increasing the modulation rate. Secondly, since any (n-1)th current-limiting layer is located on the side of the (n-1)th tunnel junction, and these layers have overlapping projections along the second direction on the sidewalls of the (n-1)th tunnel junction, the cavity length of the semiconductor optical communication device is significantly compressed. This reduces the device's resistance and relaxation oscillations, lowers the proportion of losses within the cavity, and improves its efficiency. Thirdly, the overlapping projections of any (n-1)th current-limiting layer along the second direction on the sidewalls of the (n-1)th tunnel junction mean that the area of ​​the (n-1)th tunnel junction's orthographic projection on the first Bragg reflector is smaller than the area of ​​any nth active layer's orthographic projection on the first Bragg reflector. This reduces the capacitance of the semiconductor optical communication device and also contributes to increasing the modulation rate. Semiconductor optical communication devices with higher modulation rates can help improve the communication speed and data interaction capabilities of data centers, and can save on the layout of semiconductor optical communication devices, thereby reducing costs. Attached Figure Description

[0022] 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.

[0023] Figure 1 This is a schematic diagram of the structure of a high-speed, high-efficiency, and low-cost semiconductor optical communication device according to an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the structure of a high-speed, high-efficiency, low-cost semiconductor optical communication device according to another embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the structure of a high-speed, high-efficiency, low-cost semiconductor optical communication device according to another embodiment of this application. Detailed Implementation

[0026] Currently, most existing methods for improving the modulation rate and efficiency of semiconductor optical communication devices are at the research level, usually employing various complex microstructures or complex electrode designs. However, these methods have very limited effect on improving the modulation rate of semiconductor optical communication devices. Secondly, they also introduce more energy consumption, which reduces the efficiency of semiconductor optical communication devices and makes it difficult to simultaneously improve the modulation rate and efficiency of semiconductor optical communication devices. Thirdly, the process becomes more complex, which increases the cost.

[0027] Based on this, the embodiments of this application provide a high-speed, high-efficiency, and low-cost semiconductor optical communication device, which simultaneously improves the modulation rate and efficiency of the semiconductor optical communication device while reducing its cost.

[0028] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] One embodiment of the present invention provides a high-speed, high-efficiency, and low-cost semiconductor optical communication device, referenced... Figure 1 and Figure 2 ,include:

[0032] First Bragg reflector 1;

[0033] The first active layer 2a to the Nth active layer are arranged sequentially along the first direction on one side of the first Bragg reflector 1, where N is an integer greater than or equal to 2;

[0034] From the first tunnel node 3a to the (N-1)th tunnel node, any (N-1)th tunnel node is located between the (N-1)th active layer and the nth active layer, where n is an integer greater than or equal to 2 and less than or equal to N;

[0035] The first current limiting layer 4a to the (N-1)th current limiting layer are arranged along the first direction. Any (n-1)th current limiting layer is located on the side of the (n-1)th tunnel junction along the second direction. Any (n-1)th current limiting layer has an overlapping projection along the second direction on the sidewall of the (n-1)th tunnel junction. The second direction is perpendicular to the first direction.

[0036] In this embodiment, the cascading of the (n-1)th active layer and the nth active layer is achieved through the (n-1)th tunnel junction, resulting in greater gain within the cavity and higher power output. Higher power output enables higher-order modulation coding, thereby increasing the modulation rate. Secondly, since any (n-1)th current-limiting layer is located on the side of the (n-1)th tunnel junction, and any (n-1)th current-limiting layer has overlapping projections along the second direction on the sidewall of the (n-1)th tunnel junction, the cavity length of the semiconductor optical communication device is greatly compressed. This reduces the resistance and relaxation oscillations of the semiconductor optical communication device, lowers the proportion of losses within the cavity, and improves the efficiency of the semiconductor optical communication device. Thirdly, the overlapping projections of any (n-1)th current-limiting layer along the second direction on the sidewall of the (n-1)th tunnel junction mean that the area of ​​the orthographic projection of the (n-1)th tunnel junction on the first Bragg reflector 1 is smaller than the area of ​​the orthographic projection of any nth active layer on the first Bragg reflector 1. This reduces the capacitance of the semiconductor optical communication device and also contributes to increasing the modulation rate. Semiconductor optical communication devices with higher modulation rates can help improve the communication speed and data interaction capabilities of data centers, and can save on the layout of semiconductor optical communication devices, thereby reducing costs.

[0037] Semiconductor optical communication devices are surface-emitting semiconductor light-emitting devices.

[0038] Secondly, compared with traditional semiconductor optical communication devices, under the condition of maintaining the same power, the high-speed, high-efficiency, and low-cost semiconductor optical communication device of this embodiment can greatly reduce the operating current, thereby improving the reliability of the semiconductor optical communication device and extending its lifespan.

[0039] The first active layer 2a to the Nth active layer are arranged along a first direction. For example, the first direction is perpendicular to the surface of the first Bragg reflector 1 facing the first active layer 2a.

[0040] In one embodiment, an arbitrary (n-1)th current limiting layer surrounds the (n-1)th tunnel junction. In other embodiments, it may be that an arbitrary (n-1)th current limiting layer surrounds a portion of the sidewalls of the (n-1)th tunnel junction, while another portion of the sidewalls of the (n-1)th tunnel junction is not surrounded by the (n-1)th current limiting layer.

[0041] In one embodiment, any (n-1)th current limiting layer and (n-1)th tunnel junction are disposed on the same layer.

[0042] It should be noted that the dimension of the (n-1)th current confinement layer in the first direction can be equal to the dimension of the (n-1)th tunnel junction in the first direction. Alternatively, the dimension of the (n-1)th current confinement layer in the first direction can be greater than the dimension of the (n-1)th tunnel junction in the first direction. Or, the dimension of the (n-1)th current confinement layer in the first direction can be smaller than the dimension of the (n-1)th tunnel junction in the first direction.

[0043] In one embodiment, any (n-1)th tunnel junction includes a first semiconductor layer (not shown) of a first conductivity type and a second semiconductor layer (not shown) of a second conductivity type; the first conductivity type and the second conductivity type are opposite. For example, it can be: the first conductivity type is P-type and the second conductivity type is N-type; or it can be: the first conductivity type is N-type and the second conductivity type is P-type. In any (n-1)th tunnel junction, the first semiconductor layer and the second semiconductor layer are arranged along a first direction.

[0044] In one embodiment, in any (n-1)th tunnel junction, the second semiconductor layer is located on the side of the first semiconductor layer opposite to the first Bragg reflector 1. The conductivity type of the first Bragg reflector 1 is opposite to that of the first semiconductor layer. For example, when the conductivity type of the first Bragg reflector 1 is N-type, the conductivity type of the first semiconductor layer is P-type, and the conductivity type of the second semiconductor layer is N-type.

[0045] In one embodiment, the first semiconductor layer is doped with ions of a first conductivity type, for example, the material of the first semiconductor layer is Al doped with ions of the first conductivity type. x1 Ga 1-x1 As; the second semiconductor layer is doped with ions of a second conductivity type, for example: the material of the second semiconductor layer is Al doped with ions of a second conductivity type. x2 Ga 1-x2 As. Where x1 is greater than 0 and less than 1, and x2 is greater than 0 and less than 1.

[0046] In other embodiments, the material of the first semiconductor layer includes other semiconductor materials doped with ions of a first conductivity type, and the material of the second semiconductor layer includes other semiconductor materials doped with ions of a second conductivity type.

[0047] In one embodiment, any (n-1)th current-limiting layer is a semiconductor current-limiting layer; the doping concentration of any (n-1)th current-limiting layer is much smaller than the doping concentration of the (n-1)th tunnel junction. The resistance of any (n-1)th tunnel junction is much smaller than the resistance of the (n-1)th current-limiting layer, which allows for better control of current flow along each first tunnel junction 3a to the (N-1)th tunnel junction, while minimizing current flow along the first current-limiting layer 4a to the (N-1)th current-limiting layer, thus improving current injection efficiency and reducing the possibility of current leakage. When any (n-1)th current-limiting layer is a semiconductor current-limiting layer, a third ion may or may not be doped in any (n-1)th current-limiting layer. When a third ion is doped in any (n-1)th current-limiting layer, the doping concentration of the third ion in the (n-1)th current-limiting layer is much smaller than the doping concentration of the first conductivity type ions in the first semiconductor layer and much smaller than the doping concentration of the second conductivity type ions in the second semiconductor layer. In one embodiment, when any (n-1)th current-limiting layer is a semiconductor current-limiting layer, the material of any (n-1)th current-limiting layer is Al doped with a third ion. x3 Ga 1-x3 As, or, the material of any (n-1)th current-confining layer is Al undoped with the third ion. x3 Ga 1-x3 As.

[0048] The statement that the doping concentration of any (n-1)th current-limiting layer is much smaller than the doping concentration of the (n-1)th tunnel junction means that the doping concentration of any (n-1)th current-limiting layer is less than 1 / 10 of the doping concentration of the (n-1)th tunnel junction.

[0049] When the doping concentration of any (n-1)th current-confining layer is much smaller than the doping concentration of the (n-1)th tunnel junction, for Al x1 Ga 1-x1 The values ​​of x1 in As and Al x2 Ga 1-x2 The values ​​of x2 in As, and Al x3 Ga 1-x3 There are no restrictions on the value of x3 in As.

[0050] In another embodiment, any (n-1)th current-limiting layer is an insulating current-limiting layer, for example, the material of the insulating current-limiting layer is an oxide insulating material; wherein, the Al component content in any (n-1)th tunnel junction is greater than or equal to 0.9, for example 0.9, 0.95, or 0.98. The (n-1)th current-limiting layer being in an insulating state helps to better control the current flow along the first tunnel junction 3a to the (N-1)th tunnel junction, while minimizing the current flow along the first current-limiting layer 4a to the (N-1)th current-limiting layer, thereby improving current injection efficiency and reducing the possibility of current leakage.

[0051] In one embodiment, the material of the insulating current limiting layer comprises aluminum oxide. In other embodiments, the material of the insulating current limiting layer comprises other insulating materials.

[0052] In one embodiment, in the direction from the (n-1)th current limiting layer to the (n-1)th tunnel junction, the ratio of the width of any (n-1)th current limiting layer to the width of any (n-1)th tunnel junction is 50% to 80%, for example, 50%, 60%, 70%, or 80%. If the ratio of the width of any (n-1)th current limiting layer to the width of any (n-1)th tunnel junction is less than 50%, the current limiting effect of the (n-1)th current limiting layer is reduced, the degree of current density improvement of any (n-1)th tunnel junction is reduced, and the reduction of loop capacitance is limited. If the ratio of the width of any (n-1)th current limiting layer to the width of any (n-1)th tunnel junction is greater than 80%, the degree of resistance reduction of the semiconductor optical communication device is limited, the degree of thermal efficiency reduction is limited, and the degree of lifetime improvement is limited. Therefore, a ratio of 50% to 80% between the width of any (n-1)th current limiting layer and the width of any (n-1)th tunnel junction can effectively reduce thermal effects while effectively improving the current density and lifetime of the semiconductor optical communication device.

[0053] In one embodiment, in the direction from the (n-1)th current limiting layer to the (n-1)th tunnel junction, the width of any (n-1)th tunnel junction is 1 micrometer to 20 micrometers, for example, 1 micrometer, 5 micrometer, 10 micrometer, 15 micrometer or 20 micrometer.

[0054] In one embodiment, the high-speed, high-efficiency, low-cost semiconductor optical communication device further includes: an Nth current-limiting layer located on the side of the Nth active layer opposite to the first Bragg reflector 1.

[0055] refer to Figure 1 and Figure 2 The Nth current-limiting layer includes a light-emitting region and an oxide region surrounding the light-emitting region; the light-emitting region and any (n-1)th tunnel junction are disposed opposite to each other along the first direction, and the oxide region and any (n-1)th current-limiting layer are disposed opposite to each other along the first direction. The light-emitting region is used to transmit the laser beam, and the oxide region is used to limit the optical field of the laser beam and limit the current.

[0056] In this embodiment, the high-speed, high-efficiency, and low-cost semiconductor optical communication device further includes: a second Bragg reflector 5 located on the side of the Nth current-limiting layer opposite to the first Bragg reflector 1; a semiconductor substrate layer 6 located on the side of the first Bragg reflector 1 opposite to the second Bragg reflector 5; an ohmic contact layer 7 located on the side of the second Bragg reflector 5 opposite to the first Bragg reflector 1; a front electrode layer 8 located on the side of the partial ohmic contact layer 7 opposite to the first Bragg reflector 1, wherein the front electrode layer 8 and the orthographic projection of the light-emitting region on the surface of the first Bragg reflector 1 do not overlap; simultaneously, the front electrode layer 8 and any (n-1)th tunnel junction do not overlap on the orthographic projection of the first Bragg reflector 1; and a back electrode layer 9 located on the surface of the semiconductor substrate layer 6 opposite to the first Bragg reflector 1. In this embodiment, the larger intracavity gain can support low-threshold operation even when the reflectivity of the second Bragg reflector 5 is low, which can reduce the intracavity photon lifetime and increase the modulation rate.

[0057] In one embodiment, the high-speed, high-efficiency, low-cost semiconductor optical communication device further includes: a first waveguide layer 10a to a second waveguide layer 2N, wherein the first waveguide layer 10a is located between the first Bragg reflector 1 and the first active layer 2a, the second waveguide layer 2N is located between the Nth active layer and the Nth current-limiting layer, the second waveguide layer 2n-1 is located between the nth active layer and the (n-1)th current-limiting layer, and between the nth active layer and the (n-1)th tunnel junction, and the second waveguide layer 2n-2 is located between the (n-1)th tunnel junction and the (n-1)th active layer, and between the (n-1)th active layer and the (n-1)th current-limiting layer.

[0058] In this embodiment, reference Figure 1Taking N as an integer equal to 2 as an example, the high-speed, high-efficiency, and low-cost semiconductor optical communication device includes: a first Bragg reflector 1; a first active layer 2a and a second active layer 2b arranged sequentially on one side of the first Bragg reflector 1; a first tunnel junction 3a located between the first active layer 2a and the second active layer 2b; and a first current limiting layer 4a located on the side of the first tunnel junction 3a along a second direction, the first current limiting layer 4a having an overlapping projection along the second direction on the sidewall of the first tunnel junction 3a. The semiconductor optical communication device further includes: a second current limiting layer 4b located on the side of the second active layer 2b opposite to the first Bragg reflector 1; wherein the second current limiting layer 4b includes a light-emitting region 4b2 and an oxide region 4b1 surrounding the light-emitting region 4b2; the light-emitting region 4b2 and the first tunnel junction 3a are disposed opposite to each other along the first direction, and the oxide region 4b1 and the first current limiting layer 4a are disposed opposite to each other along the first direction. The high-speed, high-efficiency, and low-cost semiconductor optical communication device also includes a second Bragg reflector 5 located on the side of the second current-limiting layer 4b facing away from the first Bragg reflector 1. The semiconductor optical communication device also includes: a first waveguide layer 10a to a fourth waveguide layer 10d, wherein the first waveguide layer 10a is located between the first Bragg reflector 1 and the first active layer 2a; the second waveguide layer 10b is located between the first active layer 2a and the first tunnel junction 3a, and between the first active layer 2a and the first current-limiting layer 4a; the third waveguide layer 10c is located between the second active layer 2b and the first tunnel junction 3a, and between the second active layer 2b and the first current-limiting layer 4a; and the fourth waveguide layer 10d is located between the second active layer 2b and the second current-limiting layer 4b. The high-speed, high-efficiency, and low-cost semiconductor optical communication device also includes: a second Bragg reflector 5 located on the side of the second current limiting layer 4b away from the first Bragg reflector 1; a semiconductor substrate layer 6 located on the side of the first Bragg reflector 1 away from the second Bragg reflector 5; an ohmic contact layer 7 located on the side of the second Bragg reflector 5 away from the first Bragg reflector 1; a front electrode layer 8 located on the side of the partial ohmic contact layer 7 away from the first Bragg reflector 1, wherein the front electrode layer 8 and the orthographic projection of the light-emitting region 4b2 on the surface of the first Bragg reflector 1 do not overlap; simultaneously, the front electrode layer 8 and the orthographic projection of the first tunnel junction 3a on the surface of the first Bragg reflector 1 do not overlap; and a back electrode layer 9 located on the side of the semiconductor substrate layer 6 away from the first Bragg reflector 1.

[0059] refer to Figure 2Another embodiment of the present invention provides a high-speed, high-efficiency, and low-cost semiconductor optical communication device, which differs from the above embodiment in that N is an integer equal to 3 as an example. The high-speed, high-efficiency, and low-cost semiconductor optical communication device includes: a first Bragg reflector 1; a first active layer 2a, a second active layer 2b, and a third active layer 2c arranged sequentially on one side of the first Bragg reflector 1; a first tunnel junction 3a and a second tunnel junction 3b, the first tunnel junction 3a being located between the first active layer 2a and the second active layer 2b; a first current limiting layer 4a and a second current limiting layer 4b, the first current limiting layer 4a being located on the side of the first tunnel junction 3a along a second direction, the first current limiting layer 4a having an overlapping projection on the sidewall of the first tunnel junction 3a along the second direction, and the second current limiting layer 4b being located on the side of the second tunnel junction 3b in a second direction, the second current limiting layer 4b having an overlapping projection on the sidewall of the second tunnel junction 3b along the second direction. The high-speed, high-efficiency, and low-cost semiconductor optical communication device further includes: a third current-limiting layer 4c, located on the side of the third active layer 2c facing away from the first Bragg reflector 1; wherein, the third current-limiting layer 4c includes a light-emitting region 4c2 and an oxide region 4c1 surrounding the light-emitting region 4c2; the light-emitting region 4c2 and the first tunnel junction 3a are arranged opposite each other along the first direction, and the light-emitting region 4c2 and the second tunnel junction 3b are arranged opposite each other along the first direction, and the oxide region 4c1 and the first current-limiting layer 4a are arranged opposite each other along the first direction, and the oxide region 4c1 and the second current-limiting layer 4b are arranged opposite each other along the first direction. The high-speed, high-efficiency, and low-cost semiconductor optical communication device further includes: a second Bragg reflector 5 located on the side of the third current-limiting layer 4b facing away from the first Bragg reflector 1. The high-speed, high-efficiency, and low-cost semiconductor optical communication device further includes: a first waveguide layer 10a to a sixth waveguide layer 10f, wherein the first waveguide layer 10a is located between the first Bragg reflector 1 and the first active layer 2a; the second waveguide layer 10b is located between the first active layer 2a and the first tunnel junction 3a, and between the first active layer 2a and the first current limiting layer 4a; the third waveguide layer 10c is located between the second active layer 2b and the first tunnel junction 3a, and between the second active layer 2b and the first current limiting layer 4a; the fourth waveguide layer 10d is located between the second active layer 2b and the second tunnel junction 3b, and between the second active layer 2b and the second current limiting layer 4b; the fifth waveguide layer 10e is located between the third active layer 2c and the second tunnel junction 3b, and between the third active layer 2c and the second current limiting layer 4b; and the sixth waveguide layer 10e is located between the third active layer 2c and the third current limiting layer 4c. The high-speed, high-efficiency, and low-cost semiconductor optical communication device also includes a second Bragg reflector 5 located on the side of the third current limiting layer 4c opposite to the first Bragg reflector 1.The semiconductor substrate layer 6 is located on the side of the first Bragg reflector 1 facing away from the second Bragg reflector 5; the ohmic contact layer 7 is located on the side of the second Bragg reflector 5 facing away from the first Bragg reflector 1; the front electrode layer 8 is located on the side of the ohmic contact layer 7 facing away from the first Bragg reflector 1, and the front electrode layer 8 and the light-emitting area 4c2 do not overlap in their orthographic projections on the surface of the first Bragg reflector 1; at the same time, the front electrode layer 8 and the first tunnel junction 3a and the second tunnel junction 3b do not overlap in their orthographic projections on the surface of the first Bragg reflector 1. The back electrode layer 9 is located on the side of the semiconductor substrate layer 6 facing away from the first Bragg reflector 1.

[0060] In other embodiments, N is an integer greater than 3, and the value of N is not limited.

[0061] Other aspects of this embodiment that are the same as those in the previous embodiments will not be described in detail.

[0062] refer to Figure 3 Another embodiment of the present invention also provides a high-speed, high-efficiency, and low-cost semiconductor optical communication device, which differs from the above embodiment in that:

[0063] The high-speed, high-efficiency, and low-cost semiconductor optical communication device also includes: a top-layer tunnel junction 3, located between the Nth active layer and the second Bragg mirror 5; wherein, the Nth current-limiting layer is located on the side of the top-layer tunnel junction 3 along the second direction, and the Nth current-limiting layer has an overlapping projection on the sidewall of the top-layer tunnel junction 3 along the second direction.

[0064] In one embodiment, the Nth current-limiting layer surrounds the top tunnel junction 3. In other embodiments, the Nth current-limiting layer may surround a portion of the sidewalls of the top tunnel junction 3, while another portion of the sidewalls of the top tunnel junction 3 is not surrounded by the Nth current-limiting layer.

[0065] The top tunnel junction 3 and any (n-1)th tunnel junction are arranged opposite each other along the first direction, and the Nth current limiting layer and any (n-1)th current limiting layer are arranged opposite each other along the first direction.

[0066] In one embodiment, the Nth current limiting layer and the top tunnel junction 3 are arranged on the same layer.

[0067] It should be noted that the dimension of the Nth current-limiting layer in the first direction can be equal to the dimension of the top tunnel junction 3 in the first direction. Alternatively, the dimension of the Nth current-limiting layer in the first direction can be greater than the dimension of the top tunnel junction 3 in the first direction. Or, the dimension of the Nth current-limiting layer in the first direction can be smaller than the dimension of the top tunnel junction 3 in the first direction.

[0068] In one embodiment, the top-layer tunnel junction 3 includes a third semiconductor layer (not shown) of a first conductivity type and a fourth semiconductor layer (not shown) of a second conductivity type; the first conductivity type and the second conductivity type are opposite. For example, the first conductivity type can be P-type and the second conductivity type can be N-type; or the first conductivity type can be N-type and the second conductivity type can be P-type. In the top-layer tunnel junction 3, the first semiconductor layer and the second semiconductor layer are arranged along a first direction.

[0069] In one embodiment, the fourth semiconductor layer is located on the side of the third semiconductor layer facing away from the first Bragg reflector 1. The conductivity type of the first Bragg reflector 1 is opposite to that of the third semiconductor layer. For example, when the conductivity type of the first Bragg reflector 1 is N-type, the conductivity type of the third semiconductor layer is P-type, and the conductivity type of the fourth semiconductor layer is N-type.

[0070] In one embodiment, the Nth current-limiting layer is a semiconductor current-limiting layer; the doping concentration of the Nth current-limiting layer is much smaller than the doping concentration of the top tunnel junction 3.

[0071] In another embodiment, the Nth current-limiting layer is an insulating current-limiting layer, and the Al component content in the top tunnel junction 3 is greater than or equal to 0.9, for example, 0.9, 0.95 or 0.98.

[0072] In one embodiment, in the direction from the Nth current-limiting layer to the top tunnel junction 3, the ratio of the width of the Nth current-limiting layer to the width of the top tunnel junction 3 is 50% to 80%, for example, 50%, 60%, 70%, or 80%. If the ratio of the width of the Nth current-limiting layer to the width of the top tunnel junction 3 is less than 50%, the current-limiting effect of the Nth current-limiting layer is reduced, the degree of improvement in the current density of the top tunnel junction 3 is reduced, and the reduction in loop capacitance is limited. If the ratio of the width of the Nth current-limiting layer to the width of the top tunnel junction 3 is greater than 80%, the degree of reduction in the lateral resistance of the semiconductor optical communication device is limited, the degree of reduction in thermal efficiency is limited, and the degree of improvement in lifetime is limited. Therefore, a ratio of 50% to 80% for the width of the Nth current-limiting layer to the width of the top tunnel junction 3 can effectively reduce thermal effects while effectively improving the current density and lifetime of the semiconductor optical communication device.

[0073] Therefore, the Nth current-limiting layer has an overlapping projection on the sidewall of the top tunnel junction 3 along the second direction, and the ratio of the width of the Nth current-limiting layer to the width of the top tunnel junction 3 is 50%~80%. This can reduce the influence of the transverse resistance in the top tunnel junction 3 by utilizing the high doping concentration of the top tunnel junction 3, while maintaining the characteristic of reducing capacitance.

[0074] In one embodiment, the width of the top tunnel junction 3 is 1 micrometer to 20 micrometers in the direction from the Nth current limiting layer to the top tunnel junction 3, for example, 1 micrometer, 5 micrometer, 10 micrometer, 15 micrometer or 20 micrometer.

[0075] Other aspects of this embodiment that are the same as those in the previous embodiments will not be described in detail.

[0076] In this embodiment, N is an integer equal to 2 as an example. (See reference...) Figure 3 The high-speed, high-efficiency, and low-cost semiconductor optical communication device includes: a first Bragg reflector 1; a first active layer 2a and a second active layer 2b arranged sequentially along a first direction on one side of the first Bragg reflector 1; a first tunnel junction 3a located between the first active layer 2a and the second active layer 2b; a first current limiting layer 4a located on the side of the first tunnel junction 3a along a second direction, the first current limiting layer 4a having an overlapping projection along the second direction on the sidewall of the first tunnel junction 3a; a second current limiting layer 4b located on the side of the second active layer 2b away from the first Bragg reflector 1; a second Bragg reflector 5 located on the side of the second current limiting layer 4b away from the first Bragg reflector 1; and a top tunnel junction 3 located between the second active layer 2b and the second Bragg reflector 5; wherein the second current limiting layer 4b is located on the side of the top tunnel junction 3 along a second direction, the second current limiting layer 4b having an overlapping projection along the second direction on the sidewall of the top tunnel junction 3. The high-speed, high-efficiency, and low-cost semiconductor optical communication device also includes: a first waveguide layer 10a to a fourth waveguide layer 10d, wherein the first waveguide layer 10a is located between the first Bragg reflector 1 and the first active layer 2a, the second waveguide layer 10b is located between the first active layer 2a and the first tunnel junction 3a, and between the first active layer 2a and the first current limiting layer 4a, the third waveguide layer 10c is located between the second active layer 2b and the first tunnel junction 3a, and between the second active layer 2b and the first current limiting layer 4a, and the fourth waveguide layer 10d is located between the second active layer 2b and the second current limiting layer 4b, and between the second active layer 2b and the top tunnel junction 3. The high-speed, high-efficiency, and low-cost semiconductor optical communication device also includes: a semiconductor substrate layer 6 located on the side of the first Bragg reflector 1 facing away from the second Bragg reflector 5; an ohmic contact layer 7 located on the side of the second Bragg reflector 5 facing away from the first Bragg reflector 1; a front electrode layer 8 located on the side of the partial ohmic contact layer 7 facing away from the first Bragg reflector 1, wherein the front electrode layer 8 and the top tunnel junction 3 have no overlapping area on the orthographic projection of the top surface of the first Bragg reflector 1; and the front electrode layer 8 and the first tunnel junction 3a have no overlapping area on the orthographic projection of the top surface of the first Bragg reflector 1; and a back electrode layer 9 located on the side of the semiconductor substrate layer 6 facing away from the first Bragg reflector 1.

[0077] Other aspects of this embodiment that are the same as those in the previous embodiments will not be described in detail.

[0078] Another embodiment of the present invention provides a method for fabricating a high-speed, high-efficiency, and low-cost semiconductor optical communication device, comprising: forming a first active layer 2a to the Nth active layer, a first tunnel junction 3a to the (N-1)th tunnel junction, and a first current limiting layer 4a to the (N-1)th current limiting layer arranged along a first direction on one side of a first Bragg reflector 1; N is an integer greater than or equal to 2; wherein, any (n-1)th tunnel junction is located between the (n-1)th active layer and the nth active layer; any (n-1)th current limiting layer is located on the side of the (n-1)th tunnel junction along a second direction, and any (n-1)th current limiting layer has an overlapping projection along the second direction on the sidewall of the (n-1)th tunnel junction, where n is an integer greater than or equal to 2 and less than or equal to N; wherein, the second direction is perpendicular to the first direction.

[0079] This application achieves the fabrication of semiconductor optical communication devices through conventional epitaxial growth without complex processes, truly realizing one-stop epitaxial growth to achieve ultra-high modulation rate and ultra-high efficiency performance in semiconductor optical communication devices. In summary, it enables the simultaneous improvement of modulation rate and efficiency in semiconductor optical communication devices at a low cost.

[0080] In this embodiment, the semiconductor optical communication device is a vertical-cavity surface-emitting laser (VCSEL). Currently, the most widely used network interconnection technology for data centers is optical communication based on VCSELs. Because semiconductor optical communication devices can simultaneously improve modulation rate and efficiency at a low cost, this greatly reduces manufacturing difficulty, enabling industrialization and resulting in significant performance improvements for semiconductor optical communication devices that have long been commercially available.

[0081] In one embodiment, the method for fabricating a high-speed, high-efficiency, and low-cost semiconductor structure further includes: providing a semiconductor substrate layer 6; and forming a first Bragg reflector 1 on one side of the semiconductor substrate layer 6 along a first direction. In one embodiment, the step of forming an arbitrary (n-1)th tunnel junction and an arbitrary (n-1)th current confinement layer includes: forming an (n-1)th initial tunnel junction (not shown) on the side of the (n-1)th active layer opposite to the first Bragg reflector 1; and oxidizing the edge region of the (n-1)th initial tunnel junction to form the (n-1)th tunnel junction and the (n-1)th current confinement layer. In this embodiment, the oxidation process includes a wet oxidation process; in other embodiments, the oxidation process includes other oxidation processes. The formed arbitrary (n-1)th current confinement layer is an insulating current confinement layer. In this case, in a specific embodiment, the Al content in the arbitrary (n-1)th initial tunnel junction is greater than or equal to 0.9, and correspondingly, the Al content in the arbitrary (n-1)th tunnel junction is greater than or equal to 0.9. Material and structural descriptions of the (n-1)th tunnel junction and the (n-1)th current confinement layer are given by reference to the descriptions of the foregoing embodiments.

[0082] For a description of the first direction and the value of N, please refer to the description in the foregoing embodiments.

[0083] In this embodiment, the method for fabricating a high-speed, high-efficiency, and low-cost semiconductor optical communication device further includes: forming a first waveguide layer 10a to a second waveguide layer 2N, wherein the first waveguide layer 10a is located between the first Bragg reflector 1 and the first active layer 2a, the second waveguide layer 2N is located between the Nth active layer and the Nth current-limiting layer, the second (n-1)th waveguide layer is located between the nth active layer and the (n-1)th current-limiting layer, and between the nth active layer and the (n-1)th tunnel junction, and the second (n-2)th initial waveguide layer is located between the (n-1)th initial tunnel junction and the (n-1)th initial active layer, and between the (n-1)th active layer and the (n-1)th current-limiting layer.

[0084] In this embodiment, the method for fabricating a high-speed, high-efficiency, and low-cost semiconductor optical communication device further includes: forming an Nth current-limiting layer on the side of the Nth active layer away from the first Bragg reflector 1; and forming a second Bragg reflector 5 on the side of the Nth current-limiting layer away from the first Bragg reflector 1.

[0085] In one embodiment, reference Figure 1 and Figure 2 The formation of the Nth current limiting layer includes forming a light-emitting region and an oxide region surrounding the light-emitting region; the light-emitting region and any (n-1)th tunnel junction are disposed opposite to each other along a first direction, and the oxide region and any (n-1)th current limiting layer are disposed opposite to each other along the first direction.

[0086] In one embodiment, the step of forming the Nth current-limiting layer includes: forming an Nth initial current-limiting layer on the side of the Nth active layer opposite to the first Bragg reflector 1; and oxidizing the edge region of the Nth initial current-limiting layer to form the Nth current-limiting layer. For example, oxidizing the edge region of the Nth initial current-limiting layer during the oxidation process of the (n-1)th initial tunnel junction simplifies the process.

[0087] In this embodiment, the method for fabricating a high-speed, high-efficiency, and low-cost semiconductor optical communication device further includes: forming an ohmic contact layer 7 on the side of the second Bragg reflector 5 facing away from the first Bragg reflector 1; and forming a front electrode layer 8 on a portion of the ohmic contact layer 7 facing away from the first Bragg reflector 1. The front electrode layer 8 has no overlapping region with the orthographic projection of the light-emitting area onto the surface of the first Bragg reflector 1; simultaneously, the front electrode layer 8 has no overlapping region with the orthographic projection of any (n-1)th tunnel junction onto the surface of the first Bragg reflector 1.

[0088] In this embodiment, the method for fabricating a high-speed, high-efficiency, and low-cost semiconductor optical communication device further includes forming a back electrode layer 9 on the side surface of the semiconductor substrate layer 6 facing away from the first Bragg reflector 1.

[0089] Another embodiment of the present invention provides a method for fabricating a high-speed, high-efficiency, and low-cost semiconductor optical communication device. The difference from the above embodiment lies in the step of forming an arbitrary (n-1)th tunnel junction and an arbitrary (n-1)th current confinement layer, which includes: forming an (n-1)th initial current confinement layer (not shown) on the side of the (n-1)th active layer opposite to the first Bragg reflector 1; forming an opening penetrating the (n-1)th initial current confinement layer in the (n-1)th initial current confinement layer, wherein the initial (n-1)th current confinement layer surrounding the opening forms the (n-1)th current confinement layer; forming an (n-1)th tunnel junction in the opening; wherein the doping concentration of the arbitrary (n-1)th current confinement layer is much smaller than the doping concentration of the (n-1)th tunnel junction. In this embodiment, the process for forming the opening penetrating the (n-1)th initial current confinement layer includes an etching process.

[0090] In this embodiment, any (n-1)th current limiting layer is a semiconductor current limiting layer.

[0091] For material and structural descriptions of any (n-1)th current-limiting layer and any (n-1)th tunnel junction, please refer to the descriptions in the foregoing embodiments.

[0092] Other aspects of this embodiment that are the same as those in the previous embodiments will not be described in detail.

[0093] Another embodiment of the present invention also provides a method for fabricating a high-speed, high-efficiency, and low-cost semiconductor optical communication device, which differs from the above embodiment in that:

[0094] Reference for Fabrication Methods of High-Speed, High-Efficiency, and Low-Cost Semiconductor Optical Communication Devices Figure 3 It also includes: forming a top-level tunnel junction 3, which is located between the Nth active layer and the second Bragg reflector 5; wherein the Nth current-limiting layer is located on the side of the top-level tunnel junction 3 along the second direction, and any Nth current-limiting layer has an overlapping projection on the sidewall of the top-level tunnel junction 3 along the second direction.

[0095] The description of forming the top-level tunnel junction 3 and the Nth current-limiting layer is the same as that in the foregoing embodiments and will not be repeated here.

[0096] Other aspects of this embodiment that are the same as those in the previous embodiments will not be described in detail.

[0097] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A high-speed, high-efficiency, low-cost semiconductor optical communication device, characterized in that, include: First Bragg reflector; The first active layer to the Nth active layer are arranged sequentially along the first direction on one side of the first Bragg reflector, where N is an integer greater than or equal to 2; From the first tunnel node to the (N-1)th tunnel node, any (N-1)th tunnel node is located between the (N-1)th active layer and the nth active layer, where n is an integer greater than or equal to 2 and less than or equal to N; The first to the (N-1)th current limiting layers are arranged along the first direction. Any (n-1)th current limiting layer is located on the side of the (n-1)th tunnel junction along the second direction and between the (n-1)th active layer and the nth active layer. Any (n-1)th current limiting layer has an overlapping projection along the second direction on the sidewall of the (n-1)th tunnel junction. In the direction from the (n-1)th current limiting layer to the (n-1)th tunnel junction, the ratio of the width of any (n-1)th current limiting layer to the width of any (n-1)th tunnel junction is 50% to 80%. The Nth current-limiting layer is located on the side of the Nth active layer opposite to the first Bragg reflector; the Nth current-limiting layer includes a light-emitting region and an oxide region surrounding the light-emitting region; the light-emitting region and any (n-1)th tunnel junction are disposed opposite to each other along the first direction and are located on the side of any (n-1)th current-limiting layer in the second direction; the oxide region and any (n-1)th current-limiting layer are disposed opposite to each other along the first direction and are located on the side of any (n-1)th tunnel junction in the second direction. A second Bragg reflector located on the side of the Nth current limiting layer opposite to the first Bragg reflector; The second direction is perpendicular to the first direction.

2. The high-speed, high-efficiency, low-cost semiconductor optical communication device according to claim 1, characterized in that, Any (n-1)th current-limiting layer is a semiconductor current-limiting layer; the doping concentration of any (n-1)th current-limiting layer is much smaller than the doping concentration of the (n-1)th tunnel junction.

3. The high-speed, high-efficiency, low-cost semiconductor optical communication device according to claim 1, characterized in that, Any (n-1)th current-limiting layer is an insulating current-limiting layer; wherein, the Al component content in any (n-1)th tunnel junction is greater than or equal to 0.

9.

4. The high-speed, high-efficiency, low-cost semiconductor optical communication device according to claim 1, characterized in that, Any (n-1)th tunnel junction includes a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type; the first conductivity type and the second conductivity type are opposite.

5. The high-speed, high-efficiency, low-cost semiconductor optical communication device according to claim 1, characterized in that, In the direction from the (n-1)th current limiting layer to the (n-1)th tunnel junction, the width of any (n-1)th tunnel junction is 1 micrometer to 20 micrometers.

6. The high-speed, high-efficiency, low-cost semiconductor optical communication device according to claim 1, characterized in that, An arbitrary (n-1)th current-limiting layer surrounds the (n-1)th tunnel junction.

7. A method for fabricating a high-speed, high-efficiency, and low-cost semiconductor optical communication device, characterized in that, include: On one side of the first Bragg reflector, a first active layer to the Nth active layer, a first tunnel junction to the (N-1)th tunnel junction, and a first current limiting layer to the (N-1)th current limiting layer arranged along the first direction are formed; N is an integer greater than or equal to 2. Wherein, any (n-1)th tunnel junction is located between the (n-1)th active layer and the nth active layer; any (n-1)th current limiting layer is located on the side of the (n-1)th tunnel junction along the second direction, and any (n-1)th current limiting layer has an overlapping projection on the sidewall of the (n-1)th tunnel junction along the second direction, where n is an integer greater than or equal to 2 and less than or equal to N; An Nth current-limiting layer is formed on the side of the Nth active layer away from the first Bragg reflector; forming the Nth current-limiting layer includes forming a light-emitting region and an oxide region surrounding the light-emitting region; the light-emitting region and any (n-1)th tunnel junction are disposed opposite to each other along the first direction and located on the side of any (n-1)th current-limiting layer in the second direction, and the oxide region and any (n-1)th current-limiting layer are disposed opposite to each other along the first direction and located on the side of any (n-1)th tunnel junction in the second direction; A second Bragg reflector is formed on the side of the Nth current-limiting layer away from the first Bragg reflector; wherein the second direction is perpendicular to the first direction.

8. The method for fabricating a high-speed, high-efficiency, low-cost semiconductor optical communication device according to claim 7, characterized in that, The steps of forming an arbitrary (n-1)th tunnel junction and an arbitrary (n-1)th current confinement layer include: forming an (n-1)th initial tunnel junction on the side of the (n-1)th active layer away from the first Bragg reflector; The edge region of the (n-1)th initial tunnel junction is oxidized to form the (n-1)th tunnel junction and the (n-1)th current confinement layer.

9. The method for fabricating a high-speed, high-efficiency, low-cost semiconductor optical communication device according to claim 7, characterized in that, The steps of forming an arbitrary (n-1)th tunnel junction and an arbitrary (n-1)th current confinement layer include: forming an (n-1)th initial current confinement layer on the side of the (n-1)th active layer away from the first Bragg reflector; An opening is formed in the (n-1)th initial current limiting layer, penetrating the (n-1)th initial current limiting layer, wherein the initial (n-1)th current limiting layer surrounding the opening forms the (n-1)th current limiting layer; The (n-1)th tunnel junction is formed in the opening; wherein the doping concentration of any (n-1)th current-limiting layer is much smaller than the doping concentration of the (n-1)th tunnel junction.

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