Laser epitaxial structure and manufacturing method thereof, VCSEL chip

Abstract

The present invention provides a laser epitaxial structure and a manufacturing method thereof, and a VCSEL chip, wherein the laser epitaxial structure comprises: a substrate, a buffer layer, an N-type DBR layer, an active region, an oxide layer, a P-type DBR layer and a P-type ohmic contact layer stacked in sequence; the N-type DBR layer and the P-type DBR layer respectively comprise a plurality of groups of alternately grown low-refractive index material layers and high-refractive index material layers, and a tunnel junction is formed between the interfaces of the low-refractive index material layers and the high-refractive index material layers, so that the internal quantum effect of the laser can be improved, and the performance of the laser can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and more specifically, to a laser epitaxial structure and a manufacturing method thereof, and a VCSEL chip. Background Art

[0002] In recent years, with the rapid development of network technology, the number of network users has increased dramatically, network congestion has become increasingly serious, and the requirements for network transmission capacity and transmission speed have become higher and higher. Among them, lasers are particularly eye-catching. It not only provides more free wavelengths, greatly reduces the operating cost and backup cost of the system, greatly improves the capacity and transmission volume of the system, but also has real-time adjustable wavelengths, which is a key component of the future all-optical network.

[0003] Existing lasers usually use multiple groups of DBRs (distributed Bragg reflectors) as reflectors of the resonant cavity, and have a certain doping concentration. The N-type DBR uses N-type doping, and the P-type DBR uses P-type doping. However, since the DBR is composed of two materials with a large refractive index difference (such as AlAs / GaAs) in a cycle, there will be a high barrier difference, and it is difficult for electrons to transition, thereby limiting the generation of a large amount of heat in the barrier junction. In the case of a large number of DBR pairs, the internal resistance of the laser increases, and the current is consumed too much in the DBR, resulting in a large threshold current of the laser, which reduces the current expansion inside the chip and seriously affects the performance of the laser. Summary of the invention

[0004] In view of this, the present invention provides a laser epitaxial structure and a manufacturing method thereof, and a VCSEL chip to solve the problem of increased internal resistance caused by connecting multiple groups of DBRs in series on both sides of the active region in the prior art.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A laser epitaxial structure, comprising:

[0007] A substrate, wherein the substrate is a conductive substrate;

[0008] A buffer layer, an N-type DBR layer, an active region, an oxide layer, a P-type DBR layer and a P-type ohmic contact layer are sequentially stacked on the surface of the substrate along a first direction; the first direction is perpendicular to the substrate and points from the substrate to the P-type ohmic contact layer; the N-type DBR layer and the P-type DBR layer respectively include a plurality of groups of alternately grown low-refractive index material layers and high-refractive index material layers, and a tunnel junction is formed between the interfaces of the low-refractive index material layer and the high-refractive index material layer.

[0009] Preferably, the low refractive index material layer includes an N-type doped layer, the high refractive index material layer includes a P-type doped layer, the tunnel junction includes a stack of an N-type high-doped layer and a P-type high-doped layer, and the N-type high-doped layer is arranged close to the N-type doped layer, and the P-type high-doped layer is arranged close to the P-type doped layer, so that a tunneling effect is formed between the N-type doped layer and the P-type doped layer.

[0010] Preferably, the starting layer and the ending layer of the N-type DBR layer along the first direction are both N-type doped; and the starting layer and the ending layer of the P-type DBR layer along the first direction are both P-type doped.

[0011] Preferably, the thickness of the N-type high-doped layer does not exceed 5 nm; the thickness of the P-type high-doped layer does not exceed 3 nm.

[0012] Preferably, the N-type doped layer and the N-type high-doped layer include Al x Ga 1-x As material layer; the P-type doped layer and the P-type high-doped layer include Al x Ga 1-x As material layer; wherein, 0<x≤0.5, 0.5<y<1.

[0013] Preferably, the doping sources of the N-type doping layer and the N-type high-doping layer both include Si or Te; the doping concentration of the N-type doping layer is 1*10E17-1*10E19, excluding endpoint values; and the doping concentration of the N-type high-doping layer is greater than or equal to 1*10E19.

[0014] Preferably, the doping sources of the P-type doping layer and the P-type high-doping layer both include Mg or Zn; the doping concentration of the P-type doping layer is 1*10E17-1*10E19, excluding endpoint values; and the doping concentration of the P-type high-doping layer is greater than or equal to 1*10E19.

[0015] Preferably, the number of groups of the N-type DBR layers that grow alternately is 0-30, excluding the endpoint value; the number of groups of the P-type DBR layers that grow alternately is 0-30, excluding the endpoint value.

[0016] The present invention also provides a method for manufacturing a laser epitaxial structure, which is used for any of the laser epitaxial structures described above, and comprises the following steps:

[0017] Step 1: providing a growth substrate;

[0018] Step 2: growing a buffer layer on the surface of the substrate;

[0019] Step 3, depositing an N-type DBR layer on the surface of the buffer layer;

[0020] The N-type DBR layer includes a plurality of groups of low-refractive index material layers and high-refractive index material layers grown alternately; and a tunnel junction is formed between the interfaces of the low-refractive index material layers and the high-refractive index material layers;

[0021] The low refractive index material layer includes an N-type doped layer, the high refractive index material layer includes a P-type doped layer, the tunnel junction includes a stack of an N-type high doped layer and a P-type high doped layer, and the N-type high doped layer is arranged close to the N-type doped layer, and the P-type high doped layer is arranged close to the P-type doped layer, so that a tunnel effect is formed between the N-type doped layer and the P-type doped layer;

[0022] The starting layer and the ending layer of the N-type DBR layer along the growth direction are both N-type doped;

[0023] The thickness of the N-type high-doped layer does not exceed 5 nm; the thickness of the P-type high-doped layer does not exceed 3 nm;

[0024] The N-type doped layer and the N-type high-doped layer include Al x Ga 1-x As material layer; the P-type doped layer and the P-type high-doped layer include Al x Ga 1-x As material layer; wherein 0<x≤0.5, 0.5<y<1;

[0025] The doping sources of the N-type doping layer and the N-type high-doping layer both include Si or Te; the doping concentration of the N-type doping layer is 1*10E17-1*10E19, excluding the endpoint value; the doping concentration of the N-type high-doping layer is greater than or equal to 1*10E19;

[0026] The number of groups of the N-type DBR layers alternately grown is 0-30 groups, excluding the endpoint value;

[0027] Step 4: growing an active region on the surface of the N-type DBR layer;

[0028] Step 5: growing an oxide layer on the surface of the active area;

[0029] Step 6: depositing a P-type DBR layer on the surface of the oxide layer;

[0030] The P-type DBR layer includes a plurality of groups of low-refractive index material layers and high-refractive index material layers grown alternately; and a tunnel junction is formed between the interfaces of the low-refractive index material layers and the high-refractive index material layers;

[0031] The low refractive index material layer includes an N-type doped layer, the high refractive index material layer includes a P-type doped layer, the tunnel junction includes a stack of an N-type high doped layer and a P-type high doped layer, and the N-type high doped layer is arranged close to the N-type doped layer, and the P-type high doped layer is arranged close to the P-type doped layer, so that a tunnel effect is formed between the N-type doped layer and the P-type doped layer;

[0032] The starting layer and the ending layer of the P-type DBR layer along the growth direction are both P-type doped;

[0033] The thickness of the N-type high-doped layer does not exceed 5 nm; the thickness of the P-type high-doped layer does not exceed 3 nm;

[0034] The N-type doped layer and the N-type high-doped layer include Al x Ga 1-x As material layer; the P-type doped layer and the P-type high-doped layer include Al x Ga 1-x As material layer; wherein 0<x≤0.5, 0.5<y<1;

[0035] The doping sources of the P-type doping layer and the P-type high-doping layer both include Mg or Zn; the doping concentration of the P-type doping layer is 1*10E17-1*10E19, excluding the endpoint value; the doping concentration of the P-type high-doping layer is greater than or equal to 1*10E19;

[0036] The number of groups of the alternately grown P-type DBR layers is 0-30, excluding the end value;

[0037] Step 7: growing a P-type ohmic contact layer on the surface of the P-type DBR layer.

[0038] A VCSEL chip, comprising:

[0039] The laser epitaxial structure described in any one of the above items;

[0040] The oxide layer is subjected to oxidation treatment, and the central area of ​​the oxide layer is an unoxidized area to form a conductive channel;

[0041] An N-type electrode is disposed on a surface of the substrate facing away from the buffer layer;

[0042] A P-type annular electrode is disposed around a surface of the P-type ohmic contact layer on one side away from the P-type DBR layer.

[0043] Through the above technical solution, the following effects are achieved:

[0044] 1. The laser epitaxial structure provided by the present invention solves the problem of increased series internal resistance caused by the accumulation of different barrier heights between multiple groups of high and low refractive index materials in the N-type DBR layer and the P-type DBR layer by arranging a tunnel junction between the interfaces of the low refractive index material layer and the high refractive index material layer of the N-type DBR layer and the P-type DBR layer, thereby effectively reducing the internal resistance of the laser, improving the internal quantum effect of the laser, and ultimately significantly improving the performance of the laser.

[0045] 2. Furthermore, by setting the low refractive index material layer to include an N-type doped layer, the high refractive index material layer to include a P-type doped layer, the tunnel junction includes a stack of an N-type high-doped layer and a P-type high-doped layer, and the N-type high-doped layer is arranged close to the N-type doped layer, and the P-type high-doped layer is arranged close to the P-type doped layer, so that a tunneling effect is formed between the N-type doped layer and the P-type doped layer, and the N-type high-doped layer and the P-type high-doped layer have a high doping concentration to form a tunneling current, which can reduce the series resistance of the N-type DBR layer and the series resistance of the P-type DBR layer, reduce heat loss, and further improve the performance of the laser.

[0046] 3. Furthermore, by setting the thickness of the N-type high-doped layer to be no more than 5nm and the thickness of the P-type high-doped layer to be no more than 3nm, since the tunneling junction includes a stack of an N-type high-doped layer and a P-type high-doped layer, if the thickness of the N-type high-doped layer and the P-type high-doped layer is too thick, the roughness of the interface between the N-type high-doped layer and the P-type high-doped layer will increase. In particular, when the doping source of the P-type high-doped layer adopts relatively large atoms such as Mg, the impact on the growth interface will be greater, resulting in poor crystal quality and affecting the tunneling effect. Limiting the thickness of the N-type high-doped layer and the P-type high-doped layer can ensure the quality of crystal growth and the tunneling effect, thereby improving the luminous efficiency of the laser.

[0047] 4. The method for manufacturing the laser epitaxial structure provided by the present invention, which is formed by the doping process of the N-type DBR layer and the P-type DBR layer, can effectively solve the problem of increased internal resistance caused by connecting multiple groups of DBRs in series on both sides of the active area, which affects the laser performance.

[0048] 5. The VCSEL chip provided by the present invention, by using the aforementioned laser epitaxial structure in combination with the use of conductive channels, N-type electrodes and P-type annular electrodes, can effectively solve the problem of low luminous efficiency and poor performance of the vertical cavity surface emitting laser caused by the increase of internal resistance due to the series connection of multiple groups of DBRs on both sides of the active area in the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0050] Figure 1 A schematic diagram of a laser epitaxial structure provided in Embodiment 1 of the present invention;

[0051] Figure 2 A schematic diagram of the N-type DBR layer structure provided in Example 1 of the present invention;

[0052] Figure 3 A schematic diagram of the P-type DBR layer structure provided in Example 1 of the present invention;

[0053] Figure 4 A schematic diagram of a laser epitaxial structure provided in Embodiment 2 of the present invention;

[0054] Figures 5 to 11 A schematic structural diagram corresponding to each step of a method for manufacturing a laser epitaxial structure provided in Embodiment 3 of the present invention;

[0055] Fig.12 A schematic diagram of a VCSEL chip structure provided by Embodiment 4 of the present invention;

[0056] Fig.13 A schematic diagram of a VCSEL chip structure provided in Embodiment 5 of the present invention;

[0057] Explanation of symbols in the figure:

[0058] 1. Substrate; 2. Buffer layer; 3. N-type DBR layer; 4. Active region; 5. Oxide layer; 5a. Conductive channel; 6. P-type DBR layer; 7. P-type ohmic contact layer; 8. N-type doped layer; 9. P-type doped layer; 10. Tunnel junction; 10a. N-type high-doped layer; 10b. P-type high-doped layer; 11. N-type electrode; 12. P-type annular electrode; 13. N-type waveguide layer; 14. P-type waveguide layer. DETAILED DESCRIPTION

[0059] To make the content of the present invention clearer, the content of the present invention is further described below in conjunction with the accompanying drawings. The present invention is not limited to this specific embodiment. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0060] Embodiment 1

[0061] This embodiment provides a laser epitaxial structure, such as Figures 1 to 3 As shown, including:

[0062] Substrate 1, substrate 1 is a conductive substrate;

[0063] A buffer layer 2, an N-type DBR layer 3, an active region 4, an oxide layer 5, a P-type DBR layer 6 and a P-type ohmic contact layer 7 are sequentially stacked on the surface of a substrate 1 along a first direction; the first direction is perpendicular to the substrate 1 and points from the substrate 1 to the P-type ohmic contact layer 7; the N-type DBR layer 3 and the P-type DBR layer 6 respectively include a plurality of groups of alternately grown low-refractive index material layers and high-refractive index material layers, and a tunnel junction 10 is formed between the interfaces of the low-refractive index material layers and the high-refractive index material layers.

[0064] The low refractive index material layer includes an N-type doped layer 8, the high refractive index material layer includes a P-type doped layer 9, the tunnel junction 10 includes a stack of an N-type high-doped layer 10a and a P-type high-doped layer 10b, and the N-type high-doped layer 10a is arranged close to the N-type doped layer 8, and the P-type high-doped layer 10b is arranged close to the P-type doped layer 9, so that a tunneling effect is formed between the N-type doped layer 8 and the P-type doped layer 9.

[0065] The starting layer and the ending layer of the N-type DBR layer 3 along the first direction are both N-type doped; the starting layer and the ending layer of the P-type DBR layer 6 along the first direction are both P-type doped.

[0066] The thickness of the N-type high-doped layer 10 a does not exceed 5 nm; the thickness of the P-type high-doped layer 10 b does not exceed 3 nm.

[0067] The N-type doped layer 8 and the N-type high-doped layer 10a include Al x Ga 1-x As material layer; P-type doped layer 9 and P-type high-doped layer 10b include Al x Ga 1-x As material layer; wherein, 0<x≤0.5, 0.5<y<1.

[0068] The doping sources of the N-type doping layer 8 and the N-type high-doping layer 10a both include Si or Te; the doping concentration of the N-type doping layer 8 ranges from 1*10E17 to 1*10E19, excluding the endpoint value; the doping concentration of the N-type high-doping layer 10a is greater than or equal to 1*10E19.

[0069] The doping sources of the P-type doping layer 9 and the P-type high-doping layer 10b both include Mg or Zn; the doping concentration of the P-type doping layer 9 ranges from 1*10E17 to 1*10E19, excluding the endpoint value; the doping concentration of the P-type high-doping layer 10b is greater than or equal to 1*10E19.

[0070] The number of groups of the N-type DBR layer 3 that grows alternately is 0-30, excluding the endpoint value; the number of groups of the P-type DBR layer 6 that grows alternately is 0-30, excluding the endpoint value.

[0071] Embodiment 2

[0072] like Figure 4 As shown, a laser epitaxial structure is different from the above-mentioned embodiment 1 in that it also includes an N-type waveguide layer 13 and a P-type waveguide layer 14, the N-type waveguide layer 13 is arranged between the N-type DBR layer 3 and the active area 4, and the P-type waveguide layer 14 is arranged between the active area 4 and the oxide layer 5.

[0073] Embodiment 3

[0074] This embodiment provides a method for manufacturing a laser epitaxial structure, which is used to manufacture the laser epitaxial structure of the first embodiment, such as Figures 5 to 11 As shown, the production method comprises the following steps:

[0075] Step 1: providing a growth substrate 1;

[0076] Step 2: growing a buffer layer 2 on the surface of the substrate 1;

[0077] Step 3, depositing an N-type DBR layer 3 on the surface of the buffer layer 2;

[0078] like Figure 2 As shown, the N-type DBR layer 3 includes a plurality of groups of low-refractive index material layers and high-refractive index material layers grown alternately; and a tunnel junction 10 is formed between the interfaces of the low-refractive index material layers and the high-refractive index material layers;

[0079] The low refractive index material layer includes an N-type doped layer 8, the high refractive index material layer includes a P-type doped layer 9, the tunnel junction 10 includes a stack of an N-type high-doped layer 10a and a P-type high-doped layer 10b, and the N-type high-doped layer 10a is arranged close to the N-type doped layer 8, and the P-type high-doped layer 10b is arranged close to the P-type doped layer 9, so that a tunnel effect is formed between the N-type doped layer 8 and the P-type doped layer 9;

[0080] The starting layer and the ending layer of the N-type DBR layer 3 along the growth direction are both N-type doped;

[0081] The thickness of the N-type high-doped layer 10a does not exceed 5 nm; the thickness of the P-type high-doped layer 10b does not exceed 3 nm;

[0082] The N-type doped layer 8 and the N-type high-doped layer 10a include Al x Ga 1-x As material layer; P-type doped layer 9 and P-type high-doped layer 10b include Al x Ga 1-x As material layer; wherein, 0<x≤0.5, 0.5<y<1.

[0083] The doping sources of the N-type doping layer 8 and the N-type high-doping layer 10a both include Si or Te, and the doping concentration of the N-type doping layer 8 ranges from 1*10E17 to 1*10E19, excluding the end value; the doping concentration of the N-type high-doping layer 10a is greater than or equal to 1*10E19;

[0084] The number of groups of the N-type DBR layer 3 alternately grown is 0-30 groups, excluding the end value;

[0085] Step 4: growing an active region 4 on the surface of the N-type DBR layer 3;

[0086] Step 5: growing an oxide layer 5 on the surface of the active area 4;

[0087] Step 6: depositing a P-type DBR layer 6 on the surface of the oxide layer 5;

[0088] like Figure 3 As shown, the P-type DBR layer 6 includes a plurality of groups of low-refractive index material layers and high-refractive index material layers grown alternately; and a tunnel junction 10 is formed between the interfaces of the low-refractive index material layers and the high-refractive index material layers;

[0089] The low refractive index material layer includes an N-type doped layer 8, the high refractive index material layer includes a P-type doped layer 9, the tunnel junction 10 includes a stack of an N-type high-doped layer 10a and a P-type high-doped layer 10b, and the N-type high-doped layer 10a is arranged close to the N-type doped layer 8, and the P-type high-doped layer 10b is arranged close to the P-type doped layer 9, so that a tunnel effect is formed between the N-type doped layer 8 and the P-type doped layer 9;

[0090] The starting layer and the ending layer of the P-type DBR layer 6 along the growth direction are both P-type doped;

[0091] The thickness of the N-type high-doped layer 10a does not exceed 5 nm; the thickness of the P-type high-doped layer 10b does not exceed 3 nm;

[0092] The N-type doped layer 8 and the N-type high-doped layer 10a include Al x Ga 1-x As material layer; P-type doped layer 9 and P-type high-doped layer 10b include Al x Ga 1-x As material layer; wherein 0<x≤0.5, 0.5<y<1;

[0093] The doping sources of the P-type doping layer 9 and the P-type high-doping layer 10b both include Mg or Zn, and the doping concentration of the P-type doping layer 9 ranges from 1*10E17 to 1*10E19, excluding the end value; the doping concentration of the P-type high-doping layer 10b is greater than or equal to 1*10E19;

[0094] The number of groups of the P-type DBR layer 6 that grow alternately is 0-30 groups, excluding the end value;

[0095] Step seven: growing a P-type ohmic contact layer 7 on the surface of the P-type DBR layer 6 .

[0096] like Figure 4 As shown, in a preferred configuration, it also includes: after step three and before step four, growing an N-type waveguide layer 13 on the surface of the N-type DBR layer 3; after step four and before step five, growing a P-type waveguide layer 14 on the surface of the active area 4 (corresponding to the laser epitaxial structure of the above-mentioned embodiment 2).

[0097] Embodiment 4

[0098] This embodiment provides a VCSEL chip, such as Fig.12 As shown, including:

[0099] The laser epitaxial structure of the first embodiment;

[0100] The oxide layer 5 is subjected to oxidation treatment, and the central area of ​​the oxide layer 5 is an unoxidized area to form a conductive channel 5a, and the size of the conductive channel 5a is set as required;

[0101] An N-type electrode 11 is disposed on a surface of the substrate 1 facing away from the buffer layer 2;

[0102] The P-type annular electrode 12 is disposed around a surface of the P-type ohmic contact layer 7 that is away from the P-type DBR layer 6 .

[0103] Embodiment 5

[0104] This embodiment provides a VCSEL chip, such as Fig.13 As shown, including:

[0105] The laser epitaxial structure of the above-mentioned embodiment 2;

[0106] The oxide layer 5 is subjected to oxidation treatment, and the central area of ​​the oxide layer 5 is an unoxidized area to form a conductive channel 5a, and the size of the conductive channel 5a is set as required;

[0107] An N-type electrode 11 is disposed on a surface of the substrate 1 facing away from the buffer layer 2;

[0108] The P-type annular electrode 12 is disposed around a surface of the P-type ohmic contact layer 7 that is away from the P-type DBR layer 6 .

[0109] In summary, through the above technical solution, the following effects are achieved:

[0110] 1. The laser epitaxial structure provided in this embodiment solves the problem of increased series internal resistance caused by the accumulation of different barrier heights between multiple groups of high and low refractive index materials in the N-type DBR layer and the P-type DBR layer by setting a tunnel junction between the interfaces of the low refractive index material layer and the high refractive index material layer in the N-type DBR layer and the P-type DBR layer, effectively reduces the internal resistance of the laser, improves the internal quantum effect of the laser, and ultimately significantly improves the performance of the laser.

[0111] 2. Furthermore, by setting the low refractive index material layer to include an N-type doped layer, the high refractive index material layer to include a P-type doped layer, the tunnel junction includes a stack of an N-type high-doped layer and a P-type high-doped layer, and the N-type high-doped layer is arranged close to the N-type doped layer, and the P-type high-doped layer is arranged close to the P-type doped layer, so that a tunneling effect is formed between the N-type doped layer and the P-type doped layer, and the N-type high-doped layer and the P-type high-doped layer have a high doping concentration to form a tunneling current, which can reduce the series resistance of the N-type DBR layer and the series resistance of the P-type DBR layer, reduce heat loss, and further improve the performance of the laser.

[0112] 3. Furthermore, by setting the thickness of the N-type high-doped layer to be no more than 5nm and the thickness of the P-type high-doped layer to be no more than 3nm, since the tunneling junction includes a stack of an N-type high-doped layer and a P-type high-doped layer, if the thickness of the N-type high-doped layer and the P-type high-doped layer is too thick, the roughness of the interface between the N-type high-doped layer and the P-type high-doped layer will increase. In particular, when the doping source of the P-type high-doped layer adopts relatively large atoms such as Mg, the impact on the growth interface will be greater, resulting in poor crystal quality and affecting the tunneling effect. Limiting the thickness of the N-type high-doped layer and the P-type high-doped layer can ensure the quality of crystal growth and the tunneling effect, thereby improving the luminous efficiency of the laser.

[0113] 4. The method for manufacturing the laser epitaxial structure provided in this embodiment, which is formed by the doping process of the N-type DBR layer and the P-type DBR layer, can effectively solve the problem of increased internal resistance caused by connecting multiple groups of DBRs in series on both sides of the active area, which affects the laser performance.

[0114] 5. The VCSEL chip provided in this embodiment, by using the aforementioned laser epitaxial structure in conjunction with the use of a conductive channel, an N-type electrode and a P-type annular electrode, can effectively solve the problem of low luminous efficiency and poor performance of the vertical cavity surface emitting laser caused by the increase of internal resistance due to the series connection of multiple groups of DBRs on both sides of the active area in the chip.

[0115] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "horizontal", "vertical", "upper", "lower", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0116] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0117] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A laser epitaxial structure, characterized in that: include: A substrate, wherein the substrate is a conductive substrate; A buffer layer, an N-type DBR layer, an active region, an oxide layer, a P-type DBR layer and a P-type ohmic contact layer are sequentially stacked on the surface of the substrate along a first direction; the first direction is perpendicular to the substrate and points from the substrate to the P-type ohmic contact layer; the N-type DBR layer and the P-type DBR layer respectively include a plurality of groups of alternately grown low-refractive index material layers and high-refractive index material layers, and a tunnel junction is formed between the interfaces of the low-refractive index material layer and the high-refractive index material layer; The low refractive index material layer includes an N-type doped layer, the high refractive index material layer includes a P-type doped layer, the tunnel junction includes a stack of an N-type high-doped layer and a P-type high-doped layer, and the N-type high-doped layer is arranged close to the N-type doped layer, and the P-type high-doped layer is arranged close to the P-type doped layer, so that a tunnel effect is formed between the N-type doped layer and the P-type doped layer; Furthermore, the starting layer and the ending layer of the N-type DBR layer along the first direction are both N-type doped; and the starting layer and the ending layer of the P-type DBR layer along the first direction are both P-type doped.

2. The laser epitaxial structure according to claim 1, characterized in that: The thickness of the N-type high-doped layer does not exceed 5 nm; the thickness of the P-type high-doped layer does not exceed 3 nm.

3. The laser epitaxial structure according to claim 1, characterized in that: The N-type doped layer and the N-type high-doped layer include Al x Ga 1-x As material layer; the P-type doped layer and the P-type high-doped layer include Al x Ga 1-x As material layer; wherein, 0<x≤0.5, 0.5<y<1.

4. The laser epitaxial structure according to claim 1, characterized in that: The doping sources of the N-type doping layer and the N-type high-doping layer both include Si or Te; the doping concentration of the N-type doping layer is 1*10E17-1*10E19, excluding endpoint values; the doping concentration of the N-type high-doping layer is greater than or equal to 1*10E19.

5. The laser epitaxial structure according to claim 1, characterized in that: The doping sources of the P-type doping layer and the P-type high-doping layer both include Mg or Zn; the doping concentration of the P-type doping layer is 1*10E17-1*10E19, excluding endpoint values; the doping concentration of the P-type high-doping layer is greater than or equal to 1*10E19.

6. The laser epitaxial structure according to claim 1, characterized in that: The number of groups of the N-type DBR layers that grow alternately is 0-30, excluding the endpoint value; the number of groups of the P-type DBR layers that grow alternately is 0-30, excluding the endpoint value.

7. A method for manufacturing a laser epitaxial structure, used for the laser epitaxial structure according to any one of claims 1 to 6, characterized in that: The production method comprises the following steps: Step 1: providing a growth substrate; Step 2: growing a buffer layer on the surface of the substrate; Step 3, depositing an N-type DBR layer on the surface of the buffer layer; The N-type DBR layer includes a plurality of groups of low-refractive index material layers and high-refractive index material layers grown alternately; and a tunnel junction is formed between the interfaces of the low-refractive index material layers and the high-refractive index material layers; The low refractive index material layer includes an N-type doped layer, the high refractive index material layer includes a P-type doped layer, the tunnel junction includes a stack of an N-type high doped layer and a P-type high doped layer, and the N-type high doped layer is arranged close to the N-type doped layer, and the P-type high doped layer is arranged close to the P-type doped layer, so that a tunnel effect is formed between the N-type doped layer and the P-type doped layer; The starting layer and the ending layer of the N-type DBR layer along the growth direction are both N-type doped; The thickness of the N-type high-doped layer does not exceed 5nm; the thickness of the P-type high-doped layer does not exceed 3nm; The N-type doped layer and the N-type high-doped layer include Al x Ga 1-x As material layer; the P-type doped layer and the P-type high-doped layer include Al x Ga 1-x As material layer; wherein 0<x≤0.5, 0.5<y<1; The doping sources of the N-type doping layer and the N-type high-doping layer both include Si or Te; the doping concentration of the N-type doping layer is 1*10E17-1*10E19, excluding the endpoint value; the doping concentration of the N-type high-doping layer is greater than or equal to 1*10E19; The number of groups of the N-type DBR layers alternately grown is 0-30 groups, excluding the endpoint value; Step 4: growing an active region on the surface of the N-type DBR layer; Step 5: growing an oxide layer on the surface of the active area; Step 6: depositing a P-type DBR layer on the surface of the oxide layer; The P-type DBR layer includes a plurality of groups of low-refractive index material layers and high-refractive index material layers grown alternately; and a tunnel junction is formed between the interfaces of the low-refractive index material layers and the high-refractive index material layers; The low refractive index material layer includes an N-type doped layer, the high refractive index material layer includes a P-type doped layer, the tunnel junction includes a stack of an N-type high doped layer and a P-type high doped layer, and the N-type high doped layer is arranged close to the N-type doped layer, and the P-type high doped layer is arranged close to the P-type doped layer, so that a tunnel effect is formed between the N-type doped layer and the P-type doped layer; The starting layer and the ending layer of the P-type DBR layer along the growth direction are both P-type doped; The thickness of the N-type high-doped layer does not exceed 5nm; the thickness of the P-type high-doped layer does not exceed 3nm; The N-type doped layer and the N-type high-doped layer include Al x Ga 1-x As material layer; the P-type doped layer and the P-type high-doped layer include Al x Ga 1-x As material layer; wherein 0<x≤0.5, 0.5<y<1; The doping sources of the P-type doping layer and the P-type high-doping layer both include Mg or Zn; the doping concentration of the P-type doping layer is 1*10E17-1*10E19, excluding the end value; the doping concentration of the P-type high-doping layer is greater than or equal to 1*10E19; The number of groups of the alternately grown P-type DBR layers is 0-30, excluding the end value; Step 7: growing a P-type ohmic contact layer on the surface of the P-type DBR layer.

8. A VCSEL chip, characterized in that: include: A laser epitaxial structure according to any one of claims 1 to 6; The oxide layer is subjected to oxidation treatment, and the central area of ​​the oxide layer is an unoxidized area to form a conductive channel; An N-type electrode is disposed on a surface of the substrate facing away from the buffer layer; A P-type annular electrode is disposed around a surface of the P-type ohmic contact layer on one side away from the P-type DBR layer.

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