Buried tunnel junction type 940nm vertical cavity surface emitting laser and preparation method thereof

Abstract

The invention relates to the technical field of vertical cavity surface emitting lasers. The invention provides a buried tunnel junction type 940nm vertical cavity surface emitting laser and a preparation method thereof, and aims to solve the problem that a traditional oxidation limiting type vertical cavity surface emitting laser has limitation, most heat flow cannot smoothly pass through an oxidation limiting layer due to obstruction of the oxidation limiting layer and can only flow to a laser emitting area of an active area from an oxidation hole to cause heat accumulation. The buried tunnel junction can effectively realize the limiting function of an electric field and a light field and replace the function of an oxidation limiting layer in the vertical cavity surface emitting laser, meanwhile, the buried tunnel junction is high in heat conductivity, the heat flow transmission efficiency can be remarkably improved, heat accumulation of an active area is remarkably relieved, and the situation that heat flow transmission is blocked is avoided; formation of the buried tunnel junction does not introduce stress, the current crowding effect is small, the heat conductivity is high, heat flow transfer is not hindered, and therefore the influence of the self-heating effect on the electro-optical performance and the thermal performance of the laser is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of vertical cavity surface emitting lasers, and more particularly to a buried tunnel junction 940nm vertical cavity surface emitting laser and a preparation method thereof. Background Art

[0002] Traditional oxide-confined VCSELs have certain limitations. For example, the formation of an oxide confinement layer introduces stress and leads to severe current crowding, which affects the VCSEL's service life and output performance. Furthermore, the oxide confinement layer's low thermal conductivity and high thermal resistance limit the efficiency of heat conduction. This can lead to the premature onset of the thermal reversal current, thereby reducing the laser's peak power. Because the Joule heat generated by the p-DBR cannot escape directly from the top, and the heat sink is located on the n-DBR side, most of the heat flow can only be transferred laterally or directly downward. Due to the obstruction of the oxide confinement layer, most of the heat flow cannot pass smoothly through the oxide confinement layer and can only flow through the oxide holes to the laser emission area of ​​the active region, causing heat to accumulate in this area. As heat accumulates, the temperature of the active region rises rapidly, exacerbating the increase in the non-radiative recombination rate of carriers while suppressing the radiative recombination rate, ultimately leading to the premature onset of the thermal reversal current and reducing device performance. Summary of the Invention

[0003] In response to the problems of weak heat transfer capability and severe self-heating faced by traditional oxide-confined vertical cavity surface emitting lasers, the present invention aims to provide a buried tunnel junction 940nm vertical cavity surface emitting laser and a preparation method. The buried tunnel junction can effectively realize the confinement function of the electric field and the optical field, replacing the function of the oxide confinement layer in the vertical cavity surface emitting laser. At the same time, the thermal conductivity of the buried tunnel junction can significantly improve the heat flow transfer efficiency, significantly alleviate the heat accumulation in the active area, and avoid the obstruction of heat flow transfer. The formation of the buried tunnel junction does not introduce stress, has a small current crowding effect, and has high thermal conductivity, which will not hinder the transfer of heat flow, thereby reducing the influence of self-heating effects on the electro-optical and thermal properties of the laser.

[0004] To achieve the above object, the present invention provides the following technical solutions: A buried tunnel junction vertical cavity surface emitting laser structure includes an n-GaAs substrate and an n-GaAs buffer layer, an n-distributed Bragg reflector, an Al 0.6 Ga 0.4 As space layer, strain compensation quantum well layer, Al 0.6 Ga 0.4 As space layer, p-distributed Bragg reflection layer, p-GaAs tunnel junction layer, n-GaAs tunnel junction layer, n-Al 0.1 Ga0.9 As cladding layer, n-distributed Bragg reflector and p-GaAs cap layer, wherein: n-GaAs substrate is grown on the crystal plane, n-GaAs buffer layer is grown on the n-GaAs substrate, n-distributed Bragg reflector is grown on the n-GaAs buffer layer, Al 0.6 Ga 0.4 The As spacer layer is grown on the n-distributed Bragg reflector, and the strain compensation quantum well layer is grown on the Al 0.6 Ga 0.4 As space layer grows, Al 0.6 Ga 0.4 As spacer layers are grown on strain-compensated quantum well layers, and p-distributed Bragg reflectors are grown on Al 0.6 Ga 0.4 As space layer, p-GaAs tunnel junction layer is grown on p-distributed Bragg reflector, n-GaAs tunnel junction layer is grown on p-GaAs tunnel junction layer, n-Al 0.1 Ga 0.9 As capping layer is grown on the n-GaAs tunnel junction layer, and n-distributed Bragg reflector is grown on the n-Al 0.1 Ga 0.9 As cladding layer is grown on the p-GaAs cap layer and on the n-distributed Bragg reflector; The strain-compensated quantum well layer consists of four GaAs 0.92 P 0.08 Barrier layer and three In 0.16 Ga 0.84 As quantum well layer, GaAs 0.92 P 0.08 Barrier layer and In 0.16 Ga 0.84 As quantum well layers are grown at intervals.

[0005] Furthermore, the GaAs of the strain-compensated quantum well layer 0.92 P 0.08 The thickness of the barrier layer is 6.2nm, In 0.16 Ga 0.84 The thickness of the As quantum wells is 4.5 nm; the thickness of the two Al 0.6 Ga 0.4 The thickness of the As spacer layer is 123 nm.

[0006] Furthermore, the thickness of the n-GaAs substrate is 250 nm and the doping concentration is 3×10 18 cm -3 The thickness of the n-GaAs buffer layer is 500 nm and the doping concentration is 2×10 18 cm -3The thickness of the n-GaAs tunnel junction layer is 15 nm and the doping concentration is 3×10 19 cm -3 The p-GaAs tunnel junction layer has a thickness of 5 nm and a doping concentration of 8×10 19 cm -3 .

[0007] Furthermore, the n-distributed Bragg reflector near the crystal plane includes 35.5 pairs of n-GaAs high refractive index layers and n-Al 0.9 Ga 0.1 As low refractive index layer, starting with Al x Ga 1-x As composition graded layer; the n-distributed Bragg reflector away from the crystal plane includes 20 pairs of n-GaAs high refractive index layers and n-Al 0.9 Ga 0.1 As low refractive index layer, starting with Al x Ga 1-x As composition graded layer; Al inserted between two layers with different refractive index x Ga 1-x As composition graded layer, n-GaAs high refractive index layer thickness is 47.6 nm, doping concentration is 2×10 18 cm -3 ;Al 0.9 Ga 0.1 The As low refractive index layer has a thickness of 55.7 nm and a doping concentration of 2×10 18 cm -3 ;Al x Ga 1-x The thickness of the As composition graded layer is 20 nm, and the doping concentration is 2.5×10 18 cm -3 The Al concentration x changes from 0 to 0.9 from the high refractive index layer to the low refractive index layer, and from 0.9 to 0 from the low refractive index layer to the high refractive index layer; the n-distributed Bragg reflector is n-type doped; the p-distributed Bragg reflector layer has a thickness of 65.7 nm and a doping concentration of 2×10 18 cm -3 , the p-distributed Bragg reflector is p-type doped.

[0008] Furthermore, the p-GaAs tunnel junction layer has a thickness of 5 nm and a doping concentration of 8×10 19 cm -3 The thickness of the n-GaAs tunnel junction layer is 15 nm and the doping concentration is 3×10 19 cm -3 .

[0009] A method for preparing a buried tunnel junction type vertical cavity surface emitting laser is used to prepare the above-mentioned buried tunnel junction type vertical cavity surface emitting laser structure, specifically comprising the following steps: Step 1. Cleaning the GaAs substrate surface: introducing hydrogen gas at a reaction chamber temperature of 700-740°C for 5-15 minutes to clean away particle contaminants and remove surface oxygen atoms. Step 2. n-GaAs buffer layer growth: The reaction chamber temperature was lowered to 650-680°C, the trimethylgallium flow rate was 90 sccm, the arsine flow rate was 440 sccm, and the silane flow rate was 50-100 sccm. The growth thickness was 500 nm, and the n-type doping concentration was 2×10 18 cm -3 ; Step 3. n-distributed Bragg reflector growth: growth temperature is 650~680℃, and the total growth period is 35.5 cycles; one growth period is: Al x Ga 1-x As composition gradient layer, n-Al 0.9 Ga 0.1 As low refractive index layer, Al x Ga 1-x As composition graded layer, n-GaAs high refractive index layer; Step 4.Al 0.6 Ga 0.4 As space layer growth: The reaction chamber temperature remains unchanged, the trimethylgallium flow rate is 55 sccm, the trimethylaluminum flow rate is 125 sccm, and the arsine flow rate is 440 sccm, and the growth thickness is 123 nm; Step 5. Strain-compensated quantum well layer growth: Step 6.Al 0.6 Ga 0.4 As spatial layer growth: same as step 4; Step 7. Growth of p-distributed Bragg reflector layer: The growth conditions are the same as in step 3, and the growth thickness is 65.7 nm; Step 8. Growth of p-GaAs tunnel junction layer: Growth temperature 550-650°C, trimethylgallium flow rate 90 sccm, arsine flow rate 440 sccm, silane flow rate 50-100 sccm, growth thickness 5 nm, p-type doping concentration 8×10 19 cm -3 ; Step 9. Growth of n-GaAs tunnel junction layer: The growth conditions are the same as those in step 8, with a growth thickness of 15 nm and an n-type doping concentration of 3×10 19 cm -3After the n-GaAs tunnel junction layer is grown, it is etched. After the light output aperture is determined, the tunnel junctions on both sides of the light output aperture are etched away and then cleaned. Step 10. n-Al 0.1 Ga 0.9 As capping layer growth: trimethylgallium flow rate of 55 sccm, trimethylaluminum flow rate of 125 sccm, arsine flow rate of 440 sccm, growth thickness of 15 nm; Step 11. n-distributed Bragg reflector growth: The growth temperature is 680 ℃ to control the Zn source doping amount, to control the n-Al 0.1 Ga 0.9 The As cap layer and the n-GaAs cap layer are doped at the same doping level. For the n-GaAs cap layer, the DEZn flow rate is 5 sccm, and for the n-Al 0.1 Ga 0.9 As cap layer, DEZn source flow rate is 50 sccm, and a total of 20 cycles are grown; one growth cycle is: Al x Ga 1-x As composition gradient layer, n-Al 0.9 Ga 0.1 As low refractive index layer, Al x Ga 1-x As composition graded layer, n-GaAs high refractive index layer; Step 12. p-GaAs cap layer growth: The reaction chamber temperature was lowered to 550-650°C, the trimethylgallium flow rate was 90 sccm, the arsine flow rate was 440 sccm, the carbon tetrabromide flow rate was 10-25 sccm, the growth thickness was 5 nm, and the n-type doping concentration was 2×10 18 cm -3 .

[0010] Furthermore, the growth process of the Bragg reflector structure is as follows: Al from high refractive index layer to low refractive index layer x Ga 1-x As composition gradient layer growth: x linearly changes from 0 to 0.9, and the doping concentration is 2.5×10 18 cm -3 , thickness is 20 nm; Al 0.9 Ga 0.1 As low refractive index layer growth: doping concentration is 2×10 18 cm -3 , thickness is 55.7nm; Al from low refractive index layer to high refractive index layer x Ga 1-xAs composition gradient layer growth: x linearly changes from 0.9 to 0, and the doping concentration is 2.5×10 18 cm -3 , thickness is 20 nm; Growth of GaAs high refractive index layer: doping concentration is 2×10 18 cm -3 , thickness is 47.6nm; In the above steps, the doping concentration is controlled by adjusting the SiH4 flow rate; n-type doping is used in the n-distributed Bragg reflector, and p-type doping is used in the p-distributed Bragg reflector.

[0011] In summary, the invention has the following beneficial effects: The buried tunnel junction of the present invention can effectively realize the limiting function of electric field and optical field, significantly improve the heat flow transfer efficiency, avoid the obstruction of heat flow transfer, significantly alleviate the heat accumulation in the active area, and reduce the negative impact of the self-heating effect on the performance of the vertical cavity surface emitting laser, thereby delaying the occurrence of the thermal reversal point and improving the peak power of the device; the p-DBR at the top of the vertical cavity surface emitting laser is converted into an n-DBR, reducing the generation of Joule heat, thereby reducing the temperature of the multi-quantum well region, so that the thermal effect of the device is more effectively controlled, achieving the purpose of reducing the Auger recombination rate, improving the radiation recombination efficiency, power, and power conversion efficiency, and improving the output power and electro-optical conversion efficiency of the vertical cavity surface emitting laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 is the current-power-voltage curve of the buried tunnel junction vertical cavity surface emitting laser of the present invention; Figure 3 is a current-power conversion efficiency characteristic curve of the buried tunnel junction vertical cavity surface emitting laser of the present invention; Figure 4 and Figure 5 These are the radiative recombination rate and Auger recombination rate diagrams when the injection current is 20 mA; Figure 6 This is the far-field divergence angle diagram of the present invention. DETAILED DESCRIPTION

[0013] The present invention will be described in further detail below with reference to the accompanying drawings.

[0014] It should be noted that, for the sake of convenience, the directions described below are consistent with the directions of the drawings themselves, but do not limit the structure of the present invention.

[0015] like Figures 1-6As shown, the present invention discloses a buried tunnel junction vertical cavity surface emitting laser structure, comprising an n-GaAs substrate and an n-GaAs buffer layer, an n-distributed Bragg reflector, an Al 0.6 Ga 0.4 As space layer, strain compensation quantum well layer, Al 0.6 Ga 0.4 As space layer, p-distributed Bragg reflection layer, p-GaAs tunnel junction layer, n-GaAs tunnel junction layer, n-Al 0.1 Ga 0.9 As cladding layer, n-distributed Bragg reflector and p-GaAs cap layer, wherein: n-GaAs substrate is grown on the crystal plane, n-GaAs buffer layer is grown on the n-GaAs substrate, n-distributed Bragg reflector is grown on the n-GaAs buffer layer, Al 0.6 Ga 0.4 The As spacer layer is grown on the n-distributed Bragg reflector, and the strain compensation quantum well layer is grown on the Al 0.6 Ga 0.4 As space layer grows, Al 0.6 Ga 0.4 As spacer layers are grown on strain-compensated quantum well layers, and p-distributed Bragg reflectors are grown on Al 0.6 Ga 0.4 As space layer, p-GaAs tunnel junction layer is grown on p-distributed Bragg reflector, n-GaAs tunnel junction layer is grown on p-GaAs tunnel junction layer, n-Al 0.1 Ga 0.9 As capping layer is grown on the n-GaAs tunnel junction layer, and n-distributed Bragg reflector is grown on the n-Al 0.1 Ga 0.9 As cladding layer is grown on the p-GaAs cap layer and on the n-distributed Bragg reflector; The strain-compensated quantum well layer consists of four GaAs 0.92 P 0.08 Barrier layer and three In 0.16 Ga 0.84 As quantum well layer, GaAs 0.92 P 0.08 Barrier layer and In 0.16 Ga 0.84 As quantum well layer is grown at intervals, and GaAs of strain-compensated quantum well layer is grown at intervals. 0.92 P 0.08 The thickness of the barrier layer is 6.2nm, In 0.16 Ga 0.84 The thickness of the As quantum wells is 4.5 nm; the thickness of the two Al 0.6 Ga 0.4The thickness of the As spacer layer is 123 nm.

[0016] The thickness of the n-GaAs substrate is 250 nm and the doping concentration is 3×10 18 cm -3 The n-GaAs buffer layer has a thickness of 500 nm and a doping concentration of 2×10 18 cm -3 ; n-Al 0.1 Ga 0.9 The As capping layer has a thickness of 15 nm and a doping concentration of 1×10 16 cm -3 The thickness of the n-GaAs cap layer is 5 nm and the doping concentration is 2×10 18 cm -3 .

[0017] The n-distributed Bragg reflector near the crystal plane consists of 35.5 pairs of n-GaAs high refractive index layers and n-Al 0.9 Ga 0.1 As low refractive index layer, starting with Al x Ga 1-x As composition graded layer; the n-distributed Bragg reflector away from the crystal plane includes 20 pairs of n-GaAs high refractive index layers and n-Al 0.9 Ga 0.1 As low refractive index layer, starting with Al x Ga 1-x As composition graded layer; Al inserted between two layers of different refractive index x Ga 1-x As composition graded layer, n-GaAs high refractive index layer thickness is 47.6 nm, doping concentration is 2×10 18 cm -3 ;Al 0.9 Ga 0.1 The As low refractive index layer has a thickness of 55.7 nm and a doping concentration of 2×10 18 cm -3 ;Al x Ga 1-x The thickness of the As composition graded layer is 20 nm, and the doping concentration is 2.5×10 18 cm -3 The Al concentration x changes from 0 to 0.9 from the high refractive index layer to the low refractive index layer, and from 0.9 to 0 from the low refractive index layer to the high refractive index layer; the n-distributed Bragg reflector is n-type doped; the p-distributed Bragg reflector layer has a thickness of 65.7 nm and a doping concentration of 2×10 18 cm -3 , p-distributed Bragg reflector is p-type doped, p-distributed Bragg reflector includes Al0.9 Ga 0.1 As low refractive index layer and Al x Ga 1-x As composition gradient layer, Al 0.9 Ga 0.1 The thickness of the As low refractive index layer is 44.039 nm, and the doping concentration is 2×10 18 cm -3 , Al x Ga 1-x The thickness of the As composition graded layer is 20 nm, and the doping concentration is 2×10 18 cm -3 , the concentration of Al x changes gradually from 0.9 to 0, inserting Al x Ga 1-x The As composition gradient layer is designed to avoid the higher voltage drop and series resistance caused by the sudden change of refractive index, reduce the impact of thermal effects on device performance, and appropriately increase the doping concentration in the gradient area to achieve the purpose of significantly reducing the potential barrier while ensuring a higher reflectivity.

[0018] The p-GaAs tunnel junction layer has a thickness of 5 nm and a doping concentration of 8×10 19 cm - The thickness of the n-GaAs tunnel junction layer is 15 nm and the doping concentration is 3×10 19 cm -3 .

[0019] The present invention also discloses a method for preparing a buried tunnel junction type vertical cavity surface emitting laser, which is used to prepare the above-mentioned buried tunnel junction type vertical cavity surface emitting laser structure, specifically comprising the following steps: Step 1. Cleaning the GaAs substrate surface: introducing hydrogen gas at a reaction chamber temperature of 700-740°C for 5-15 minutes to clean away particle contaminants and remove surface oxygen atoms. Step 2. n-GaAs buffer layer growth: The reaction chamber temperature was lowered to 650-680°C, the trimethylgallium flow rate was 90 sccm, the arsine flow rate was 440 sccm, and the silane flow rate was 50-100 sccm. The growth thickness was 500 nm, and the n-type doping concentration was 2×10 18 cm -3 ; Step 3. n-distributed Bragg reflector growth: growth temperature is 650~680℃, and the total growth period is 35.5 cycles; one growth period is: Al x Ga 1-x As composition gradient layer, n-Al 0.9 Ga 0.1 As low refractive index layer, Al x Ga 1-xAs composition graded layer, n-GaAs high refractive index layer; Step 4.Al 0.6 Ga 0.4 As space layer growth: The reaction chamber temperature remains unchanged, the trimethylgallium flow rate is 55 sccm, the trimethylaluminum flow rate is 125 sccm, and the arsine flow rate is 440 sccm, and the growth thickness is 123 nm; Step 5. Strain-compensated quantum well layer growth: Step 6.Al 0.6 Ga 0.4 As space layer growth: same as step 4; Step 7. Growth of p-distributed Bragg reflector layer: The growth conditions are the same as in step 3, and the growth thickness is 65.7 nm; Step 8. Growth of p-GaAs tunnel junction layer: Growth temperature 550-650°C, trimethylgallium flow rate 90 sccm, arsine flow rate 440 sccm, silane flow rate 50-100 sccm, growth thickness 5 nm, p-type doping concentration 8×10 19 cm -3 ; Step 9. Growth of n-GaAs tunnel junction layer: The growth conditions are the same as step 8, with a growth thickness of 15 nm and an n-type doping concentration of 3×10 19 cm -3 After the n-GaAs tunnel junction layer is grown, it is etched. The appropriate light output aperture is selected according to actual needs. After the light output aperture is determined, the tunnel junctions on both sides of the light output aperture are etched away and then cleaned. Step 10. n-Al 0.1 Ga 0.9 As capping layer growth: trimethylgallium flow rate of 55 sccm, trimethylaluminum flow rate of 125 sccm, arsine flow rate of 440 sccm, growth thickness of 15 nm; Step 11. n-distributed Bragg reflector growth: The growth temperature is 680 ℃ to control the Zn source doping amount, to control the n-Al 0.1 Ga 0.9 The As cap layer and the n-GaAs cap layer are doped at the same doping level. For the n-GaAs cap layer, the DEZn flow rate is 5 sccm, and for the n-Al 0.1 Ga 0.9 As capping layer, DEZn source flow rate is 50 sccm, and a total of 20 cycles are grown; one growth cycle is: Al x Ga 1-x As composition gradient layer, n-Al 0.9 Ga 0.1 As low refractive index layer, Al x Ga1-x As component gradient layer, n-GaAs high refractive index layer Step 12. Growth of p-GaAs cap layer: the reaction chamber temperature is reduced to 550-650 DEG C, the trimethylgallium flow rate is 90 sccm, the arsine flow rate is 440 sccm, the carbon tetrabromide flow rate is 10-25 sccm, the thickness is 5 nm, and the n-type doping concentration is 2*10 18 cm -3 .

[0020] The growth process of the DBR laser structure is as follows: Al x Ga 1-x As component gradient layer growth: x is linearly changed from 0 to 0.9, the doping concentration is 2.5*10 18 cm -3 , and the thickness is 20 nm; Al 0.9 Ga 0.1 As low refractive index layer growth: the doping concentration is 2*10 18 cm -3 , and the thickness is 55.7 nm; Al x Ga 1-x As component gradient layer growth: x is linearly changed from 0.9 to 0, the doping concentration is 2.5*10 18 cm -3 , and the thickness is 20 nm; GaAs high refractive index layer growth: the doping concentration is 2*10 18 cm -3 , and the thickness is 47.6 nm; In the above steps, the doping concentration is controlled by adjusting the SiH4 flow rate; the n-type doping is used in the n-distributed Bragg reflector, and the p-type doping is used in the p-distributed Bragg reflector.

[0021] The structural schematic diagram of the present application is shown in the figure, the current-power-voltage and current-power conversion efficiency characteristic curves of the structure of the present application are shown in the figure, the radiation recombination rate and Auger recombination rate diagrams of the present application at an injection current of 20 mA are shown in the figure, and the far field divergence angle diagram of the structure of the present application is shown in the figure. Figure 1 Figure 2 Figure 3 Figure 4 The structure of the present application can simultaneously realize the delay of the thermal turnover point, the reduction of the voltage, the improvement of the power conversion efficiency, and the reduction of the divergence angle.

[0022] ​​​The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A buried tunnel junction vertical cavity surface emitting laser structure, characterized by: It includes an n-GaAs substrate and an n-GaAs buffer layer, an n-distributed Bragg reflector, an Al 0.6 Ga 0.4 As space layer, strain compensation quantum well layer, Al 0.6 Ga 0.4 As space layer, p-distributed Bragg reflection layer, p-GaAs tunnel junction layer, n-GaAs tunnel junction layer, n-Al 0.1 Ga 0.9 As cladding layer, n-distributed Bragg reflector and p-GaAs cap layer, wherein: The n-GaAs substrate is grown on the crystal plane, the n-GaAs buffer layer is grown on the n-GaAs substrate, the n-distributed Bragg reflector is grown on the n-GaAs buffer layer, and the Al 0.6 Ga 0.4 The As spacer layer is grown on the n-distributed Bragg reflector, and the strain compensation quantum well layer is grown on the Al 0.6 Ga 0.4 As space layer grows, Al 0.6 Ga 0.4 As spacer layers are grown on strain-compensated quantum well layers, and p-distributed Bragg reflectors are grown on Al 0.6 Ga 0.4 As space layer, p-GaAs tunnel junction layer is grown on p-distributed Bragg reflector, n-GaAs tunnel junction layer is grown on p-GaAs tunnel junction layer, n-Al 0.1 Ga 0.9 As capping layer is grown on the n-GaAs tunnel junction layer, and n-distributed Bragg reflector is grown on the n-Al 0.1 Ga 0.9 As cladding layer is grown on the p-GaAs cap layer and on the n-distributed Bragg reflector; The strain compensation quantum well layer includes four GaAs 0.92 P 0.08 Barrier layer and three In 0.16 Ga 0.84 As quantum well layer, GaAs 0.92 P 0.08 Barrier layer and In 0.16 Ga 0.84 As quantum well layers are grown at intervals.

2. The buried tunnel junction vertical cavity surface emitting laser structure according to claim 1, characterized in that: The GaAs strain-compensated quantum well layer 0.92 P 0.08 The thickness of the barrier layer is 6.2nm, In 0.16 Ga 0.84 The thickness of the As quantum wells is 4.5nm; the thickness of the two Al 0.6 Ga 0.4 The thickness of the As spacer layer is 123 nm.

3. The buried tunnel junction vertical cavity surface emitting laser structure according to claim 1, characterized in that: The thickness of the n-GaAs substrate is 250 nm and the doping concentration is 3×10 18 cm -3 The thickness of the n-GaAs buffer layer is 500 nm and the doping concentration is 2×10 18 cm -3 The thickness of the n-GaAs tunnel junction layer is 15 nm and the doping concentration is 3×10 19 cm -3 The p-GaAs tunnel junction layer has a thickness of 5 nm and a doping concentration of 8×10 19 cm -3 .

4. The buried tunnel junction vertical cavity surface emitting laser structure according to claim 1, characterized in that: The n-distributed Bragg reflector near the crystal plane consists of 35.5 pairs of n-GaAs high refractive index layers and n-Al 0.9 Ga 0.1 As low refractive index layer, starting with Al x Ga 1-x As composition graded layer; the n-distributed Bragg reflector away from the crystal plane includes 20 pairs of n-GaAs high refractive index layers and n-Al 0.9 Ga 0.1 As low refractive index layer, starting with Al x Ga 1-x As composition graded layer; Al inserted between two layers with different refractive index x Ga 1-x As composition graded layer, n-GaAs high refractive index layer thickness is 47.6 nm, doping concentration is 2×10 18 cm -3 ;Al 0.9 Ga 0.1 The As low refractive index layer has a thickness of 55.7 nm and a doping concentration of 2×10 18 cm -3 ;Al x Ga 1-x The thickness of the As composition graded layer is 20 nm, and the doping concentration is 2.5×10 18 cm -3 , where the Al concentration x gradually changes from 0 to 0.9 from the high refractive index layer to the low refractive index layer, and from 0.9 to 0 from the low refractive index layer to the high refractive index layer; the n-distributed Bragg reflector is n-type doped; The p-distributed Bragg reflector layer has a thickness of 65.7 nm and a doping concentration of 2×10 18 cm -3 , the p-distributed Bragg reflector is p-type doped.

5. The buried tunnel junction vertical cavity surface emitting laser structure according to claim 1, characterized in that: The p-GaAs tunnel junction layer has a thickness of 5 nm and a doping concentration of 8×10 19 cm -3 The thickness of the n-GaAs tunnel junction layer is 15 nm and the doping concentration is 3×10 19 cm -3 .

6. A method for preparing a buried tunnel junction vertical cavity surface emitting laser, for preparing the buried tunnel junction vertical cavity surface emitting laser structure according to any one of claims 1 to 5, characterized in that: The specific steps include: Step 1. Cleaning the GaAs substrate surface: introducing hydrogen gas at a reaction chamber temperature of 700-740°C for 5-15 minutes to clean away particle contaminants and remove surface oxygen atoms. Step 2. n-GaAs buffer layer growth: The reaction chamber temperature was lowered to 650-680°C, the trimethylgallium flow rate was 90 sccm, the arsine flow rate was 440 sccm, and the silane flow rate was 50-100 sccm. The growth thickness was 500 nm, and the n-type doping concentration was 2×10 18 cm -3 ; Step 3. n-distributed Bragg reflector growth: growth temperature is 650~680℃, and the total growth period is 35.5 cycles; one growth period is: Al x Ga 1-x As composition gradient layer, n-Al 0.9 Ga 0.1 As low refractive index layer, Al x Ga 1-x As composition graded layer, n-GaAs high refractive index layer; Step 4.Al 0.6 Ga 0.4 As space layer growth: The reaction chamber temperature remains unchanged, the trimethylgallium flow rate is 55 sccm, the trimethylaluminum flow rate is 125 sccm, and the arsine flow rate is 440 sccm, and the growth thickness is 123 nm; Step 5. Strain-compensated quantum well layer growth: Step 6.Al 0.6 Ga 0.4 As spatial layer growth: same as step 4; Step 7. Growth of p-distributed Bragg reflector layer: The growth conditions are the same as in step 3, and the growth thickness is 65.7 nm; Step 8. Growth of p-GaAs tunnel junction layer: Growth temperature 550-650°C, trimethylgallium flow rate 90 sccm, arsine flow rate 440 sccm, silane flow rate 50-100 sccm, growth thickness 5 nm, p-type doping concentration 8×10 19 cm -3 ; Step 9. Growth of n-GaAs tunnel junction layer: The growth conditions are the same as step 8, with a growth thickness of 15 nm and an n-type doping concentration of 3×10 19 cm -3 After the n-GaAs tunnel junction layer is grown, it is etched. After the light output aperture is determined, the tunnel junctions on both sides of the light output aperture are etched away and then cleaned. Step 10. n-Al 0.1 Ga 0.9 As capping layer growth: trimethylgallium flow rate of 55 sccm, trimethylaluminum flow rate of 125 sccm, arsine flow rate of 440 sccm, growth thickness of 15 nm; Step 11. n-distributed Bragg reflector growth: The growth temperature is 680 ℃ to control the Zn source doping amount, to control the n-Al 0.1 Ga 0.9 The As cap layer and the n-GaAs cap layer are doped at the same doping level. For the n-GaAs cap layer, the DEZn flow rate is 5 sccm, and for the n-Al 0.1 Ga 0.9 As capping layer, DEZn source flow rate is 50 sccm, and a total of 20 cycles are grown; one growth cycle is: Al x Ga 1-x As composition gradient layer, n-Al 0.9 Ga 0.1 As low refractive index layer, Al x Ga 1-x As composition graded layer, n-GaAs high refractive index layer; Step 12. p-GaAs cap layer growth: The reaction chamber temperature was lowered to 550-650°C, the trimethylgallium flow rate was 90 sccm, the arsine flow rate was 440 sccm, the carbon tetrabromide flow rate was 10-25 sccm, the growth thickness was 5 nm, and the n-type doping concentration was 2×10 18 cm -3 .

7. The method for preparing a buried tunnel junction vertical cavity surface emitting laser according to claim 6, wherein: The growth process of the Bragg reflector structure is as follows: Al from high refractive index layer to low refractive index layer x Ga 1-x As composition gradient layer growth: x linearly changes from 0 to 0.9, and the doping concentration is 2.5×10 18 cm -3 , thickness is 20 nm; Al 0.9 Ga 0.1 As low refractive index layer growth: doping concentration is 2×10 18 cm -3 , thickness is 55.7nm; Al from low refractive index layer to high refractive index layer x Ga 1-x As composition gradient layer growth: x linearly changes from 0.9 to 0, and the doping concentration is 2.5×10 18 cm -3 , thickness is 20 nm; Growth of GaAs high refractive index layer: doping concentration is 2×10 18 cm -3 , thickness is 47.6nm; In the above steps, the doping concentration is controlled by adjusting the SiH4 flow rate; n-type doping is used in the n-distributed Bragg reflector, and p-type doping is used in the p-distributed Bragg reflector.

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