A low-power AlGaInP red light semiconductor laser with limited layer strain and optimized packaging stress and a method for preparing the same

Abstract

The present invention relates to a low-power AlGaInP red semiconductor laser with optimized packaging stress by restricting layer strain and a preparation method thereof. The laser includes a substrate, a buffer layer, a lower transition layer, a lower confinement layer, a graded lower waveguide layer, a first quantum well, a barrier layer, a second quantum well, a graded upper waveguide layer, an (Al 1‑x8 Ga x8 ) y5 In 1‑y5 P first upper confinement layer, an etch stop layer, an (Al 1‑x10 Ga x10 ) y6 In 1‑y6 P second upper confinement layer, an upper transition layer, and a cap layer, which are sequentially arranged from bottom to top; wherein, 0 ≤ x8 ≤ 0.3, 0.4 ≤ y5 ≤ 0.6; 0.15 ≤ x10 ≤ 0.3, 0.4 ≤ y6 ≤ 0.48. By growing the second upper confinement layer with tensile strain, the present invention compensates for the packaging stress and reduces the residual stress generated during the sintering process; combined with a low-aluminum-component AlGaInP with higher thermal conductivity as the second upper confinement layer, the heat dissipation capacity is enhanced, the temperature of the active region is reduced, the service life of the low-power AlGaInP red semiconductor laser is improved, and the working reliability of the laser is increased.

Description

Technical Field

[0001] The invention relates to a low-power AlGaInP red light semiconductor laser with limited layer strain and optimized packaging stress and a preparation method thereof, belonging to the technical field of optoelectronics. Background Art

[0002] Semiconductor lasers have the advantages of high efficiency, long life, high beam quality, good stability, and compact structure, and are widely used in optical fiber communication, laser pumping, medical equipment, optical image processing, laser printers, etc. Among them, low-power AlGaInP red semiconductor lasers have a small output power (generally less than 100mW) and have broad application prospects in medical beauty, laser display, industrial measurement, laser printing, etc. In these applications, extending the service life of semiconductor lasers and improving the reliability of devices will help broaden the application scope of low-power AlGaInP red semiconductor lasers and increase market share.

[0003] In addition to being related to the chip's own structural design, the reliability of semiconductor lasers is closely related to the packaging structure. In order to improve the thermal conductivity of the laser, low-power AlGaInP red semiconductor lasers are usually packaged with AlN, SiC, etc., which have higher thermal conductivity. However, due to the large difference in thermal expansion coefficient between the heat sink material and the semiconductor laser chip (2 to 3 times), a large stress is generated after packaging, affecting the heat dissipation and long-term reliability of the laser. Therefore, in order to improve the long-term reliability of the laser, effective technical means must be used to reduce the packaging stress.

[0004] The packaging structure of the currently commonly used low-power AlGaInP red light semiconductor laser chip is to sequentially epitaxially grow the lower confinement layer, the light-emitting active area, the first upper confinement layer, the corrosion stop layer, and the second upper confinement layer on the semiconductor substrate, and then etch and remove the second upper confinement layer above the corrosion stop layer by photolithography and vapor phase epitaxial growth methods to form the light-emitting gain region A, and then deposit the P-side electrical contact layer to form the current injection region W, and finally deposit the N-side electrical contact layer. The output power and stability of the laser are improved by the confinement effect of the current injection region W and the light gain region A on electrons and photons. The laser chip is sintered to a heat sink using AuSn solder with the P surface facing downward. In this process, the metal solder deforms much more than the semiconductor chip during the temperature rise and fall process of sintering, so that the solder on both sides of the light-emitting gain region produces significant residual stress on the light-emitting gain region A after sintering.

[0005] The existing methods for solving packaging stress mainly focus on three aspects: (1) Optimizing the heat sink material to reduce the difference in thermal expansion coefficient with the semiconductor chip, thereby reducing packaging stress. For example, Chinese patent CN105018779A discloses a ceramic particle gradient enhanced Cu heat sink and its preparation method. The different ceramic particle content in each layer of the heat sink and the corresponding thermal expansion coefficient are used to weld the chip to the functional layer that matches its thermal expansion coefficient, thereby reducing the welding internal stress between the chip and the heat sink and improving the service life of the semiconductor laser; Chinese patent CN106159670A proposes a method for improving the heat dissipation efficiency of semiconductor lasers and a corresponding packaging structure, which uses a graphite metal composite heat sink prepared by multiple groups of metals and graphite in an intermittent arrangement to solve the problem of laser chip damage caused by thermal stress; however, this method makes the heat sink manufacturing process complicated and the cost increased. (2) Optimize the chip structure design, add a new chip multi-channel design, increase the contact area between the chip and the solder, and buffer thermal stress. For example, Chinese patent CN110224300A proposes a semiconductor laser structure and a preparation method thereof, which increases the contact area with the solder during welding and packaging by setting periodically arranged holes and N-current blocking layers on the chip, firmly bonds, buffers thermal stress, and improves the photoelectric conversion efficiency. However, this method requires adding chip manufacturing processes, which is complicated and increases the difficulty of stable production monitoring. (3) Annealing heat treatment after packaging to eliminate packaging stress. For example, Chinese patent CN1710762A discloses a method for improving the yield of semiconductor lasers, which involves an improvement in the semiconductor laser packaging process, placing a laser component that has completed other packaging processes but has not yet been capped into a sealed container with good thermal conductivity for high and low temperature cycling to release residual packaging stress. However, this method also requires additional process steps, which increases costs, and the AuSn solder migrates during the heat treatment process, which is easy to cause cavity surface damage. Summary of the invention

[0006] To solve the above problems, the present invention provides a low-power AlGaInP red light semiconductor laser with a confinement layer strain-optimized packaging stress and a preparation method thereof. On the basis of the existing packaging process, the second upper confinement layer is strained to grow to compensate for the packaging stress and reduce the residual stress generated during the sintering process; the low-aluminum component AlGaInP with higher thermal conductivity is combined as the second upper confinement layer to enhance the heat dissipation capacity, reduce the active area temperature, increase the service life of the low-power AlGaInP red light semiconductor laser, and increase the working reliability.

[0007] The technical solution of the present invention is as follows:

[0008] The first aspect of the present invention provides a low-power AlGaInP red light semiconductor laser with optimized packaging stress by limiting layer strain, the laser comprising a substrate, a buffer layer, a lower transition layer, a lower limiting layer, a gradient lower waveguide layer, a first quantum well, a barrier layer, a second quantum well, a gradient upper waveguide layer, (Al 1-x8 Ga x8 ) y5 In 1-y5 P first upper limiting layer, etching stop layer, (Al 1-x10 Ga x10 ) y6 In 1-y6 P second upper limiting layer, upper transition layer and cap layer;

[0009] Among them, 0≤x8≤0.3, 0.4≤y5≤0.6; 0.15≤x10≤0.3, 0.4≤y6≤0.48.

[0010] Among them, the y6 component is less than y5, and the second upper confinement layer is grown with low aluminum component AlGaInP to increase thermal conductivity and improve heat dissipation capacity, and y5-y6≤0.2 to avoid excessive conduction band gap difference, increase the difficulty of hole migration, and reduce photoelectric conversion efficiency; the y6 component is less than 0.48, so that the second upper confinement layer maintains tensile strain, compensates for packaging stress during welding, reduces the influence of residual stress on reliability, and improves the service life of low-power AlGaInP red light semiconductor lasers.

[0011] Preferably, according to the present invention, the low-power AlGaInP red semiconductor laser of the limiting layer strain optimization package stress includes one or more of the following conditions:

[0012] I. The substrate is a GaAs substrate;

[0013] II. The buffer layer is a GaAs buffer layer;

[0014] III. The lower transition layer is Ga 1-x1 In x1 P lower transition layer; 0.45≤x1≤0.55;

[0015] IV. The lower limiting layer is (Al 1-x2 Ga x2 ) y1 In 1-y1 P lower limiting layer; 0≤x2≤0.3, 0.4≤y1≤0.6;

[0016] V. The graded lower waveguide layer is (Al 1-x3 Ga x3 ) y2 In 1-y2P gradient lower waveguide layer; 0.05≤x3≤0.6, 0.4≤y2≤0.6;

[0017] VI. The first quantum well is Ga 1-x4 In x4 P first quantum well; 0.3≤x4≤0.7;

[0018] VII. The barrier layer is (Al 1-x5 Ga x5 ) y3 In 1-y3 P barrier layer; 0.25≤x5≤0.7, 0.4≤y3≤0.6;

[0019] VIII. The second quantum well is Ga 1-x6 In x6 P second quantum well; 0.3≤x6≤0.7;

[0020] IX. The graded upper waveguide layer is (Al 1-x7 Ga x7 ) y4 In 1-y4 P gradient upper waveguide layer; 0.05≤x7≤0.6, 0.4≤y4≤0.6;

[0021] X. The corrosion stop layer is Ga 1-x9 In x9 P corrosion stop layer; 0.5≤x9≤0.7;

[0022] XI. The upper transition layer is Ga 1-x11 In x11 P upper transition layer; 0.45≤x11≤0.55;

[0023] XII. The cap layer is a GaAs cap layer.

[0024] According to the preferred embodiment of the present invention, in the low-power AlGaInP red light semiconductor laser in which the confinement layer strain optimizes the packaging stress, (Al 1-x8 Ga x8 ) y5 In 1-y5 The thickness of the first upper confinement layer P is 0.05-0.25 μm, 0≤x8≤0.3, 0.4≤y5≤0.6, and the doping concentration is 5E17-1E18 atoms / cm 3 ;(Al 1-x10 Ga x10 ) y6 In 1-y6 The thickness of the second upper confinement layer is 0.5-1.2 μm, 0.15≤x10≤0.3, 0.4≤y6≤0.48, and the doping concentration is 5E17-1.5E18 atoms / cm 3 .

[0025] According to the present invention, the optimized confinement layer doped low-power AlGaInP red semiconductor laser includes one or more of the following conditions:

[0026] ①. The buffer layer is a GaAs buffer layer, and the doping concentration of the GaAs buffer layer is 2E18 to 5E18 atoms / cm 3 , thickness is 0.1~0.3μm;

[0027] ②. The lower transition layer is Ga 1-x1 In x1 P lower transition layer, Ga 1-x1 In x1 The doping concentration of the P lower transition layer is 1E18-3E18 atoms / cm 3 , thickness is 0.1~0.3μm; 0.45≤x1≤0.55;

[0028] ③. The lower limiting layer is n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 P lower confinement layer, n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 The thickness of the P lower confinement layer is 0.5 to 1.5 μm, and the doping concentration is 5E17 to 3E18 atoms / cm 3 ;

[0029] ④. The gradient lower waveguide layer is (Al 1-x3 Ga x3 ) y2 In 1-y2 P graded lower waveguide layer, (Al 1-x3 Ga x3 ) y2 In 1-y2 The thickness of the P gradient waveguide layer is 0.05-0.15 μm, unintentionally doped, 0.05≤x3≤0.6, 0.4≤y2≤0.6;

[0030] ⑤. The first quantum well is Ga 1-x4 In x4 P first quantum well, Ga 1-x4 In x4 The thickness of the first quantum well P is 4-7 nm, unintentionally doped, 0.3≤x4≤0.7;

[0031] ⑥. The barrier layer is (Al 1-x5 Ga x5 ) y3 In 1-y3 P barrier layer, (Al1-x5 Ga x5 ) y3 In 1-y3 The thickness of the P barrier layer is 5 to 15 nm, unintentionally doped, 0.25≤x5≤0.7, 0.4≤y3≤0.6;

[0032] ⑦. The second quantum well is Ga 1-x6 In x6 P second quantum well, Ga 1-x6 In x6 The thickness of the second quantum well P is 4-7 nm, unintentionally doped, 0.3≤x6≤0.7;

[0033] ⑧. The gradient upper waveguide layer is (Al 1-x7 Ga x7 ) y4 In 1-y4 P graded upper waveguide layer, (Al 1-x7 Ga x7 ) y4 In 1-y4 The thickness of the P graded upper waveguide layer is 0.05-0.15 μm, and one-half of it near the first upper confinement layer is doped with 0.05≤x7≤0.6, 0.4≤y4≤0.6;

[0034] ⑨. Etch stop layer is P-type Ga 1-x9 In x9 P corrosion stop layer, P-type Ga 1-x9 In x9 The thickness of the P corrosion stop layer is 0.01 to 0.05 μm, and the doping concentration is 5E17 to 2E18 atoms / cm 3 , 0.4≤x9≤0.6;

[0035] ⑩. The upper transition layer is P-type Ga 1-x11 In x11 P upper transition layer, P-type Ga 1-x11 In x11 The thickness of the transition layer on P is 0.01-0.05 μm, and the doping concentration is 1E18-3E18 atoms / cm 3 , 0.4≤x11≤0.6;

[0036] The cap layer is a GaAs cap layer with a thickness of 0.1 to 0.5 μm and a doping concentration of 4E19 to 1E20 atoms / cm 3 .

[0037] According to the present invention, the optimized confinement layer doped low-power AlGaInP red semiconductor laser includes one or more of the following conditions:

[0038] ①. The buffer layer is a GaAs buffer layer, and the doping concentration of the GaAs buffer layer is 4E18 atoms / cm 3 , thickness is 0.2μm;

[0039] ②. The lower transition layer is Ga 1-x1 In x1 P lower transition layer, Ga 1-x1 In x1 The doping concentration of the P lower transition layer is 2E18 atoms / cm 3 , x1 = 0.5, thickness is 0.1 μm;

[0040] ③. The lower limiting layer is n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 P lower confinement layer, n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 The thickness of the P lower confinement layer is 1.2 μm, x2=0, y1=0.5, and the doping concentration is 1E18 atoms / cm 3 ;

[0041] ④. The gradient lower waveguide layer is (Al 1-x3 Ga x3 ) y2 In 1-y2 P graded lower waveguide layer, (Al 1-x3 Ga x3 ) y2 In 1-y2 The thickness of the waveguide layer under the P gradient is 0.08 μm, it is not intentionally doped, x3 gradients from 0.05 to 0.55, y2 = 0.5;

[0042] ⑤. The first quantum well is Ga 1-x4 In x4 P first quantum well, Ga 1-x4 In x4 The thickness of the first quantum well of P is 5 nm, it is not intentionally doped, and x4 = 0.4;

[0043] ⑥. The barrier layer is (Al 1-x5 Ga x5 ) y3 In 1-y3 P barrier layer, (Al 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the P barrier layer is 6 nm, unintentionally doped, x5 = 0.5, y3 = 0.5;

[0044] ⑦. The second quantum well is Ga1-x6 In x6 P second quantum well, Ga 1-x6 In x6 The thickness of the second quantum well P is 5 nm, unintentionally doped, x6 = 0.4;

[0045] ⑧. The gradient upper waveguide layer is (Al 1-x7 Ga x7 ) y4 In 1-y4 P graded upper waveguide layer, (Al 1-x7 Ga x7 ) y4 In 1-y4 The thickness of the P gradient upper waveguide layer is 0.08 μm, x7 gradients from 0.5 to 0.05, y2 = 0.5, and the doping concentration is 4E17 atoms / cm 3 ;

[0046] ⑨. Etch stop layer is P-type Ga 1-x9 In x9 P corrosion stop layer, P-type Ga 1-x9 In x9 The thickness of the P corrosion stop layer is 0.01 μm, x9=0.6, and the doping concentration is 1E18 atoms / cm 3 ;

[0047] ⑩. The upper transition layer is P-type Ga 1-x11 In x11 P upper transition layer, P-type Ga 1-x11 In x11 The thickness of the transition layer on P is 0.01 μm, x11=0.5, and the doping concentration is 2E18 atoms / cm 3 ;

[0048] The cap layer is a GaAs cap layer with a thickness of 0.2 μm and a doping concentration of 7E19 atoms / cm 3 .

[0049] The second aspect of the present invention provides a method for preparing a low-power AlGaInP red semiconductor laser with optimized confinement layer doping, the method comprising the following steps: performing surface heat treatment on a substrate in an MOCVD growth chamber, and then epitaxially growing a buffer layer, a lower transition layer, a lower confinement layer, a gradient lower waveguide layer, a first quantum well, a barrier layer, a second quantum well, a gradient upper waveguide layer, (Al 1-x8 Ga x8 ) y5 In 1-y5 P first upper limiting layer, etching stop layer, (Al 1-x10 Ga x10 )y6 In 1-y6 P second upper limiting layer, upper transition layer and cap layer;

[0050] Among them, in (Al 1-x8 Ga x8 ) y5 In 1-y5 The first upper confinement layer and (Al 1-x10 Ga x10 ) y6 In 1-y6 The conditions for the second upper confinement layer of P are: growth temperature 690-710℃, introduction of TMAl, TMIn, TMGa and PH 3 .

[0051] Specifically, a method for preparing a low-power AlGaInP red light semiconductor laser with limited layer strain and optimized packaging stress comprises the following steps:

[0052] S1, place the GaAs substrate in the growth chamber of the MOCVD equipment, H 2 The environment temperature was raised to 720±10℃ and baked, and AsH 3 , performing surface heat treatment on the GaAs substrate;

[0053] S2, slowly lowering the temperature to 680±10°C at a rate of not less than 30°C / min, continuing to introduce TMGa and AsH3 to grow a GaAs buffer layer on the GaAs substrate;

[0054] S3, the temperature is maintained at 680±10℃, TMGa, TMIn and PH3 are introduced, and Ga is grown on the GaAs transition layer. 1-x1 In x1 P lower transition layer;

[0055] S4, the temperature is slowly changed to 700±10°C, the heating rate is not more than 60°C / min, TMAl, TMIn, TMGa and PH3 are introduced, and n-type (Al) is grown on the lower transition layer. 1-x2 Ga x2 ) y1 In 1-y1 P lower limiting layer;

[0056] S5, the temperature is slowly changed to 650±10℃, and TMAl, TMIn, TMGa and PH are introduced. 3 , grown on the lower confinement layer (Al 1-x3 Ga x3 ) y2 In 1-y2 P gradient lower waveguide layer;

[0057] S6, the temperature is maintained at 650±10℃, and TMIn, TMGa and PH are continuously introduced. 3 , Ga is grown on the graded lower waveguide layer 1-x4 In x4 P first quantum well;

[0058] S7, the temperature is maintained at 650±10℃, and TMAl, TMIn, TMGa and PH are introduced 3 , grown on the first quantum well (Al 1-x5 Ga x5 ) y3 In 1-y3 P barrier layer;

[0059] S8, the temperature is maintained at 650±10℃, and TMIn, TMGa and PH are continuously introduced. 3 , Ga is grown on the barrier layer 1- x6 In x6 P second quantum well;

[0060] S9, the temperature is slowly changed to 700±10℃, and TMAl, TMIn, TMGa and PH are continuously introduced. 3 , grown on the first quantum well (Al 1-x7 Ga x7 ) y4 In 1-y4 P graded upper waveguide layer;

[0061] S10, the temperature is maintained at 700±10℃, and TMIn, TMAl, TMGa and PH are continuously introduced. 3 , grow a P-type (Al 1-x8 Ga x8 ) y5 In 1-5 P first upper limiting layer;

[0062] S11, the temperature is maintained at 700±10℃, and TMIn, TMGa and PH are continuously introduced. 3 , grow P-type Ga on the first upper confinement layer 1-x9 In x9 P corrosion stop layer;

[0063] S12, the temperature is maintained at 700±10℃, and TMIn, TMAl, TMGa and PH are continuously introduced. 3 , grow a P-type (Al 1-x10 Ga x10 ) y6 In 1-y6 P second upper limiting layer;

[0064] S13, the temperature is gradually changed to 680±10℃, and TMGa, AsH3 and PH are introduced 3 In the P-type (Al 1-x10 Ga x10 ) y6 In 1- y6 Ga is grown on the second upper confinement layer 1-x11 In x11 P upper transition layer;

[0065] S14, lower the temperature to 540±10℃, continue to introduce TMGa and AsH 3 , a GaAs cap layer is grown on the upper transition layer.

[0066] According to a preferred embodiment of the present invention, in step S2, the doping concentration of the GaAs transition layer is 2E18 to 5E18 atoms / cm 3 , with a thickness of 0.1 to 0.3 μm; further preferably, the thickness of the GaAs transition layer is 0.2 μm, and the doping concentration is 4E18 atoms / cm 3 .

[0067] According to the preferred embodiment of the present invention, in step S3, the Ga 1-x1 In x1 The doping concentration of the P gradient lower transition layer is 1E18~3E18 atoms / cm 3 , thickness is 0.1-0.3 μm, 0.45≤x1≤0.55; more preferably, x1=0.5, thickness is 0.1 μm, and doping concentration is 2E18 atoms / cm 3 .

[0068] According to the preferred embodiment of the present invention, in step S4, n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 The thickness of the P lower confinement layer is 0.5 to 1.5 μm, and the doping concentration is 5E17 to 3E18 atoms / cm 3 , 0≤x2≤0.3, 0.4≤y1≤0.6; further preferably, x2=0, y1=0.5, the thickness is 1.2μm, and the doping concentration is 1E18 atoms / cm 3 .

[0069] According to the preferred embodiment of the present invention, in step S5, (Al 1-x3 Ga x3 ) y2 In 1-y2The thickness of the P gradient waveguide layer is 0.05-0.15 μm, it is not intentionally doped, 0.05≤x3≤0.6, 0.4≤y2≤0.6; further preferably, x3 gradients from 0.05 to 0.55, y2=0.5, and the thickness is 0.08 μm.

[0070] According to the preferred embodiment of the present invention, in step S6, the Ga 1-x4 In x4 The thickness of the P first quantum well is 4-7 nm, it is not intentionally doped, 0.3≤x4≤0.7; more preferably, x4=0.4, and the thickness is 5 nm.

[0071] According to the preferred embodiment of the present invention, in step S7, (Al 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the P barrier layer is 5-15 nm, it is not intentionally doped, 0.25≤x5≤0.7, 0.4≤y3≤0.6; more preferably, x5=0.5, y3=0.5, and the thickness is 6 nm.

[0072] According to the preferred embodiment of the present invention, in step S8, the Ga 1-x6 In x6 The thickness of the P second quantum well is 4-7 nm, it is not intentionally doped, 0.3≤x6≤0.7; more preferably, x6=0.4, and the thickness is 5 nm.

[0073] According to a preferred embodiment of the present invention, in step S9, the (Al 1-x7 Ga x7 ) y4 In 1-y4 The thickness of the P gradient upper waveguide layer is 0.05-0.15 μm, and one-half of it near the first upper confinement layer is doped, 0.05≤x7≤0.6, 0.4≤y4≤0.6; further preferably, x7 gradients from 0.5 to 0.05, y2=0.5, the thickness is 0.08 μm, and the doping concentration is 4E17 atoms / cm 3 .

[0074] According to the preferred embodiment of the present invention, in step S10, the P-type (Al 1-x8 Ga x8 ) y5 In 1-y5 The thickness of the first upper confinement layer is 0.05-0.25 μm, and the doping concentration is 5E17-1E18 atoms / cm 3 , 0≤x8≤0.3, 0.4≤y5≤0.6; further preferably, x8=0, y5=0.5, the thickness is 0.15μm, and the doping concentration is 6E17 atoms / cm 3 .

[0075] According to the preferred embodiment of the present invention, in step S11, the P-type Ga 1-x9 In x9 The thickness of the P corrosion stop layer is 0.01 to 0.05 μm, and the doping concentration is 5E17 to 1.2E18 atoms / cm 3 , 0.4≤x9≤0.6; further preferably, x9=0.6, the thickness is 0.01μm, and the doping concentration is 1E18 atoms / cm 3 .

[0076] According to the preferred embodiment of the present invention, in step S12, the P-type (Al 1-x10 Ga x10 ) y6 In 1-y6 The thickness of the second upper confinement layer is 0.5-1.2 μm, and the doping concentration is 5E17-1.5E18 atoms / cm 3 , 0.15≤x10≤0.3, 0.4≤y6≤0.48; further preferably, x10=0.25, y6=0.45, thickness is 0.7μm, doping concentration is 8E17 atoms / cm 3 .

[0077] According to the preferred embodiment of the present invention, in step S13, the P-type Ga 1-x11 In x11 The thickness of the transition layer on P is 0.01-0.05 μm, and the doping concentration is 1E18-3E18 atoms / cm 3 , 0.4≤x11≤0.6; further preferably, x11=0.5, the thickness is 0.01μm, and the doping concentration is 2E18 atoms / cm 3 .

[0078] According to a preferred embodiment of the present invention, in step S14, the cap layer has a thickness of 0.1-0.5 μm and a doping concentration of 4E19-1E20 atoms / cm 3 ; Further preferably, the thickness is 0.2 μm and the doping concentration is 7E19 atoms / cm 3 .

[0079] Preferably according to the present invention, the dopant in steps S2-S4 is Si, the dopant in steps S9-S13 is Mg, and the dopant in step S14 is C.

[0080] The beneficial effects of the present invention are:

[0081] The present invention compensates for packaging stress and reduces residual stress generated during sintering by tensile strain growth of the second upper limiting layer; combines low-aluminum component AlGaInP with higher thermal conductivity as the second upper limiting layer to enhance heat dissipation capability, reduce active area temperature, increase the service life of a low-power AlGaInP red light semiconductor laser, and increase the working reliability of the laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 The figures are a simplified structure of a laser chip (a), a force diagram of a conventional chip package (b), and a force diagram of a laser package according to Embodiment 1 of the present invention (c).

[0083] In the figure: 1 is the lower confinement layer, 2 is the light-emitting active area (composed of quantum well and waveguide layer), 3 is the first upper confinement layer, 4 is the corrosion stop layer, 5 is the second upper confinement layer, 6 is the P-side electric contact layer, 7 is the N-side electric contact layer 7, 8 is AuSn solder, and 9 is the heat sink.

[0084] Figure 2 is a schematic structural diagram of the laser described in Example 1 of the present invention;

[0085] 10 is a GaAs substrate, 11 is a GaAs buffer layer, 12 is a Ga 1-x1 In x1 P lower transition layer, 13 is (Al 1-x2 Ga x2 ) y1 In 1-y1 P lower limiting layer, 14 is (Al 1-x3 Ga x3 ) y2 In 1-y2 P is the lower waveguide layer with gradient, 15 is Ga 1-x4 In x4 P first quantum well, 16 is (Al 1-x5 Ga x5 ) y3 In 1-y3 P barrier layer, 17 is Ga 1-x6 In x6 P second quantum well, 18 is (Al 1-x7 Ga x7 ) y4 In 1-y4 P gradient upper waveguide layer, 19 is (Al 1-x8 Ga x8 ) y5 In 1-y5 P is the first upper confinement layer, 20 is Ga 1-x9 In x9 P corrosion stop layer, 21 is (Al 1- x10 Gax10 ) y6 In 1-y6 P is the second upper confinement layer, 22 is Ga 1-x11 In x11 The transition layer 23 on P is a GaAs cap layer.

[0086] Figure 3 These are the results of 50-60-70°C gradient aging tests of a conventional laser (a) and the laser described in Example 1 of the present invention (b).

[0087] In the figure: the vertical axis is the current, unit: mA, and the horizontal axis is the aging time, unit: h. DETAILED DESCRIPTION

[0088] The present invention will be further described below with reference to the embodiments and drawings, but is not limited thereto.

[0089] Embodiment 1:

[0090] like Figure 2 As shown, a low-power AlGaInP red light semiconductor laser with a limited layer strain optimized packaging stress, the laser comprises a GaAs substrate, a GaAs buffer layer, a GaAs substrate, and a GaAs substrate arranged in sequence from bottom to top. 1-x1 In x1 P lower transition layer, (Al 1- x2 Ga x2 ) y1 In 1-y1 P lower confinement layer, (Al 1-x3 Ga x3 ) y2 In 1-y2 P graded lower waveguide layer, Ga 1-x4 In x4 P first quantum well, (Al 1- x5 Ga x5 ) y3 In 1-y3 P barrier layer, Ga 1-x6 In x6 P second quantum well, (Al 1-x7 Ga x7 ) y4 In 1-y4 P graded upper waveguide layer, (Al 1- x8 Ga x8 ) y5 In 1-y5 P first upper confinement layer, Ga 1-x9 In x9 P corrosion stop layer, (Al 1-x10 Ga x10 )y6 In 1-y6 P second upper confinement layer, Ga 1-x11 In x11 P upper transition layer and GaAs cap layer.

[0091] The preparation method comprises the following steps:

[0092] S1, place the GaAs substrate in the growth chamber of the MOCVD equipment, H 2 The environment temperature was raised to 720±10℃ and baked, and AsH 3 , performing surface heat treatment on the GaAs substrate;

[0093] S2, slowly lower the temperature to 680±10℃, with a cooling rate of no less than 30℃ / min, continue to introduce TMGa and AsH3, and grow a GaAs transition layer on the GaAs substrate; the growth thickness is 0.2μm, and the doping concentration is 4E18 atoms / cm 3 , the doping element is Si;

[0094] S3, the temperature is maintained at 680±10℃, TMGa, TMIn and PH3 are introduced, and Ga is grown on the GaAs transition layer. 1-x1 In x1 P lower transition layer, growth thickness is 0.1μm, x1=0.5, doping concentration is 2E18 atoms / cm 3 , the doping element is Si;

[0095] S4, the temperature is slowly changed to 700±10°C, the heating rate is not more than 60°C / min, TMAl, TMIn, TMGa and PH3 are introduced, and n-type (Al) is grown on the lower transition layer. 1-x2 Ga x2 ) y1 In 1-y1 P lower confinement layer, growth thickness is 1.2 μm, x2=0, doping concentration is 1E18 atoms / cm 3 , the doping element is Si;

[0096] S5, the temperature is slowly changed to 650±10℃, and TMAl, TMIn, TMGa and PH are introduced. 3 , grown on the lower confinement layer (Al 1-x3 Ga x3 ) y2 In 1-y2 P gradient lower waveguide layer; growth thickness is 0.08μm, x3 gradient from 0.05 to 0.55, y2=0.5, unintentional doping;

[0097] S6, the temperature is maintained at 650±10℃, and TMIn, TMGa and PH are continuously introduced. 3, Ga is grown on the lower waveguide layer 1-x4 In x4 P first quantum well, growth thickness is 5nm, x4=0.4, no intentional doping;

[0098] S7, the temperature is maintained at 650±10℃, and TMAl, TMIn, TMGa and PH are introduced 3 , grown on the first quantum well (Al 1-x5 Ga x5 ) y3 In 1-y3 P barrier layer, grown to a thickness of 6 nm, x5 = 0.5, y3 = 0.5, unintentionally doped;

[0099] S8, the temperature is maintained at 650±10℃, and TMIn, TMGa and PH are continuously introduced. 3 , Ga is grown on the barrier layer 1- x6 In x6 P second quantum well, grown to a thickness of 5nm, x6=0.4, unintentionally doped;

[0100] S9, the temperature is slowly changed to 700±10℃, and TMAl, TMIn, TMGa and PH are continuously introduced. 3 , grown on the first quantum well (Al 1-x7 Ga x7 ) y4 In 1-y4 The P gradient upper waveguide layer has a growth thickness of 0.08 μm, and one-half of it is doped near the first upper confinement layer. x7 is gradually changed from 0.5 to 0.05, y2 = 0.5, and the doping concentration is 4E17 atoms / cm 3 , the doping element is Mg;

[0101] S10, the temperature is maintained at 700±10℃, and TMIn, TMAl, TMGa and PH are continuously introduced. 3 , grow a P-type (Al 1-x8 Ga x8 ) y5 In 1-5 P is the first upper confinement layer, with a growth thickness of 0.15 μm, x8=0, y5=0.5, and a doping concentration of 6E17 atoms / cm 3 , the doping element is Mg;

[0102] S11, the temperature is maintained at 700±10℃, and TMIn, TMGa and PH are continuously introduced. 3 , grow P-type Ga on the first upper confinement layer 1-x9 In x9P corrosion stop layer, growth thickness is 0.01μm, x9=0.6, doping concentration is 1E18 atoms / cm 3 . The doping element is Mg;

[0103] S12, the temperature is maintained at 700±10℃, and TMIn, TMAl, TMGa and PH are continuously introduced. 3 , grow a P-type (Al 1-x10 Ga x10 ) y6 In 1-y6 The second upper confinement layer P has a growth thickness of 0.7 μm, x10=0.25, y6=0.45, and a doping concentration of 8E17 atoms / cm 3 , the doping element is Mg;

[0104] S13, the temperature is gradually changed to 680±10℃, and TMGa, AsH3 and PH are introduced 3 In the P-type (Al 1-x10 Ga x10 ) y6 In 1- y6 Ga is grown on the second upper confinement layer 1-x11 In x11 The transition layer on P has a growth thickness of 0.01 μm, x11=0.5, and a doping concentration of 2E18 atoms / cm 3 , the doping element is Mg;

[0105] S14, lower the temperature to 540±10℃, continue to introduce TMGa and AsH 3 A GaAs cap layer is grown on the upper transition layer with a growth thickness of 0.02 μm and a doping concentration of 7E19 atoms / cm 3 , the doping element is C.

[0106] The simple structure of laser chip is as follows Figure 1 (a), conventional chip packaging stress Figure 1 (b) The force on the laser package described in Example 1 is as follows: Figure 1As shown in (c), a lower confinement layer, a light-emitting active region, a first upper confinement layer, an etching stop layer, and a second upper confinement layer are sequentially epitaxially grown on a semiconductor substrate. The second upper confinement layer above the etching stop layer is etched and removed by photolithography and vapor phase epitaxial growth methods to form a light-emitting gain region A. Then, a P-side electrical contact layer is deposited to form a current injection region W. Finally, an N-side electrical contact layer is deposited. The output power and stability of the laser are improved by the confinement effect of the current injection region W and the light-emitting gain region A on electrons and photons. The laser chip is sintered to a heat sink using AuSn solder with the P surface facing downward. In this process, the metal solder deforms much more than the semiconductor chip during the heating and cooling process of sintering, so that the solder on both sides of the light-emitting gain region generates significant residual stress on the light-emitting gain region A after sintering.

[0107] Depend on Figure 1 (b) and Figure 1 (c) By comparison, it can be seen that in this embodiment, the second upper confinement layer is grown with tensile strain to compensate for the packaging stress, reduce the residual stress generated during the sintering process, and help reduce the residual stress after packaging. The second upper confinement layer of the laser in this embodiment is grown with a low Al component to enhance the heat dissipation capacity of the chip. At the same time, y6 is less than 0.48, and tensile strain growth is used to compensate for the packaging stress.

[0108] Embodiment 2:

[0109] A method for preparing a low-power AlGaInP red light semiconductor laser with limited layer strain and optimized packaging stress comprises the following steps:

[0110] S1, place the GaAs substrate in the growth chamber of the MOCVD equipment, H 2 The environment temperature was raised to 720±10℃ and baked, and AsH 3 , performing surface heat treatment on the GaAs substrate;

[0111] S2, slowly lower the temperature to 680±10℃, with a cooling rate of no less than 30℃ / min, continue to introduce TMGa and AsH3, and grow a GaAs transition layer on the GaAs substrate; the growth thickness is 0.15μm, and the doping concentration is 3E18 atoms / cm 3 , the doping element is Si;

[0112] S3, the temperature is maintained at 680±10℃, TMGa, TMIn and PH3 are introduced, and Ga is grown on the GaAs transition layer. 1-x1 In x1 P lower transition layer, growth thickness is 0.2μm, x1=0.45, doping concentration is 1.5E18 atoms / cm 3 , the doping element is Si;

[0113] S4, the temperature is slowly changed to 700±10°C, the heating rate is not more than 60°C / min, TMAl, TMIn, TMGa and PH3 are introduced, and n-type (Al) is grown on the lower transition layer. 1-x2 Ga x2 ) y1 In 1-y1 The P lower confinement layer has a growth thickness of 1.0 μm, x2 = 0.1, and a doping concentration of 2E18 atoms / cm 3 , the doping element is Si;

[0114] S5, the temperature is slowly changed to 650±10℃, and TMAl, TMIn, TMGa and PH are introduced. 3 , grown on the lower confinement layer (Al 1-x3 Ga x3 ) y2 In 1-y2 P gradient lower waveguide layer; growth thickness is 0.1μm, x3 gradient changes from 0.05 to 0.5, y2=0.5, unintentional doping;

[0115] S6, the temperature is maintained at 650±10℃, and TMIn, TMGa and PH are continuously introduced. 3 , Ga is grown on the lower waveguide layer 1-x4 In x4 P first quantum well, growth thickness is 6nm, x4=0.5, unintentional doping;

[0116] S7, the temperature is maintained at 650±10℃, and TMAl, TMIn, TMGa and PH are introduced 3 , grown on the first quantum well (Al 1-x5 Ga x5 ) y3 In 1-y3 P barrier layer, grown to a thickness of 8 nm, x5 = 0.4, y3 = 0.55, unintentionally doped;

[0117] S8, the temperature is maintained at 650±10℃, and TMIn, TMGa and PH are continuously introduced. 3 , Ga is grown on the barrier layer 1- x6 In x6 P second quantum well, grown to a thickness of 6nm, x6=0.5, unintentionally doped;

[0118] S9, the temperature is slowly changed to 700±10℃, and TMAl, TMIn, TMGa and PH are continuously introduced. 3 , grown on the first quantum well (Al 1-x7 Ga x7 ) y4 In 1-y4The P gradient upper waveguide layer has a growth thickness of 0.08 μm, and half of it is doped near the first upper confinement layer. x7 is gradually changed from 0.5 to 0.1, y2 = 0.45, and the doping concentration is 3E17 atoms / cm 3 , the doping element is Mg;

[0119] S10, the temperature is maintained at 700±10℃, and TMIn, TMAl, TMGa and PH are continuously introduced. 3 , grow a P-type (Al 1-x8 Ga x8 ) y5 In 1-5 P is the first upper confinement layer, with a growth thickness of 0.2 μm, x8=0.1, y5=0.45, and a doping concentration of 7E17 atoms / cm 3 , the doping element is Mg;

[0120] S11, the temperature is maintained at 700±10℃, and TMIn, TMGa and PH are continuously introduced. 3 , grow P-type Ga on the first upper confinement layer 1-x9 In x9 P corrosion stop layer, growth thickness is 0.03μm, x9=0.5, doping concentration is 7E17 atoms / cm 3 . The doping element is Mg;

[0121] S12, the temperature is maintained at 700±10℃, and TMIn, TMAl, TMGa and PH are continuously introduced. 3 , grow a P-type (Al 1-x10 Ga x10 ) y6 In 1-y6 The second upper confinement layer P has a growth thickness of 1.0 μm, x10=0.2, y6=0.4, and a doping concentration of 9E17 atoms / cm 3 , the doping element is Mg;

[0122] S13, the temperature is gradually changed to 680±10℃, and TMGa, AsH3 and PH are introduced 3 In the P-type (Al 1-x10 Ga x10 ) y6 In 1- y6 Ga is grown on the second upper confinement layer 1-x11 In x11 The transition layer on P has a growth thickness of 0.03 μm, x11=0.4, and a doping concentration of 1E18 atoms / cm 3 , the doping element is Mg;

[0123] S14, lower the temperature to 540±10℃, continue to introduce TMGa and AsH 3 A GaAs cap layer is grown on the upper transition layer with a growth thickness of 0.02 μm and a doping concentration of 7E19 atoms / cm 3 , the doping element is C.

[0124] Embodiment 3:

[0125] A method for preparing a low-power AlGaInP red light semiconductor laser with limited layer strain and optimized packaging stress, wherein the steps are as described in Example 2, except that in S10, x8=0.3, y5=0.6, and the thickness is 0.18 μm; in S12, x10=0.15, y6=0.42, and the thickness is 1.1 μm.

[0126] Embodiment 4:

[0127] A method for preparing a low-power AlGaInP red light semiconductor laser with limited layer strain and optimized packaging stress, wherein the steps are as described in Example 2, except that in S10, x8=0, y5=0.6, and the thickness is 0.12 μm; in S12, x10=0.1, y6=0.48, and the thickness is 0.6 μm.

[0128] Test example

[0129] A conventional laser and the laser described in Example 1 of the present invention were subjected to a 50-60-70°C gradient aging test.

[0130] The method of 50-60-70℃ gradient aging test is as follows: for the packaged product, the working current at different temperatures is tested at rated power; in this experiment, the product is aged at 50 / 60 / 70℃ for 2h respectively, and the change of working current is detected; after aging, the change of optical output power at 20mA and the optical output power before aging is tested at room temperature, and the attenuation ratio of optical output power is calculated.

[0131] Aging test results such as Figure 3 As shown by Figure 3 (a) and Figure 3 (b) It can be seen that the operating current of the laser described in Example 1 is relatively small at different operating temperatures, indicating that the heat dissipation capacity is improved; at the same time, the optical output power attenuation ratio of the laser described in Example 1 at 20mA before and after aging is 11.6%, which is 17.5% less than that of conventional lasers. It can be foreseen that the service life will increase and the reliability will be improved.

Claims

1. A low-power AlGaInP red light semiconductor laser with optimized packaging stress by limiting layer strain, the laser comprising a substrate, a buffer layer, a lower transition layer, a lower limiting layer, a gradient lower waveguide layer, a first quantum well, a barrier layer, a second quantum well, a gradient upper waveguide layer, (Al 1-x8 Ga x8 ) y5 In 1-y5 P first upper limiting layer, corrosion stop layer, (Al 1- x10 Ga x10 ) y6 In 1-y6 P second upper limiting layer, upper transition layer and cap layer; in, 0≤x8≤0.3, 0.4≤y5≤0.6; 0.15≤x10≤0.3, 0.4≤y6≤0.48, y6 component is less than y5, and y5-y6≤0.

2.

2. The low-power AlGaInP red semiconductor laser with optimized packaging stress by limiting layer strain according to claim 1, It is characterized in that The low-power AlGaInP red semiconductor laser wherein the confinement layer strain optimizes the package stress includes one or more of the following conditions: I. The substrate is a GaAs substrate; II. The buffer layer is a GaAs buffer layer; III. The lower transition layer is Ga 1-x1 In x1 P lower transition layer; 0.45≤x1≤0.55； IV. The lower limiting layer is (Al 1-x2 Ga x2 ) y1 In 1-y1 P lower limiting layer; 0≤x2≤0.3, 0.4≤y1≤0.6; V. The graded lower waveguide layer is (Al 1-x3 Ga x3 ) y2 In 1-y2 P gradient lower waveguide layer; 0.05≤x3≤0.6, 0.4≤y2≤0.6; VI. The first quantum well is Ga 1-x4 In x4 P first quantum well; 0.3≤x4≤0.7； VII. The barrier layer is (Al 1-x5 Ga x5 ) y3 In 1-y3 P barrier layer; 0.25≤x5≤0.7, 0.4≤y3≤0.6; VIII. The second quantum well is Ga 1-x6 In x6 P second quantum well; 0.3≤x6≤0.7； IX. The graded upper waveguide layer is (Al 1-x7 Ga x7 ) y4 In 1-y4 P gradient upper waveguide layer; 0.05≤x7≤0.6, 0.4≤y4≤0.6; X. The corrosion stop layer is Ga 1-x9 In x9 P corrosion stop layer; 0.5≤x9≤0.7; XI. The upper transition layer is Ga 1-x11 In x11 P upper transition layer; 0.45≤x11≤0.55； XII. The cap layer is a GaAs cap layer.

3. The low-power AlGaInP red light semiconductor laser with optimized packaging stress by limiting layer strain according to claim 1, It is characterized in that The confinement layer strain optimizes the packaging stress of low-power AlGaInP red semiconductor lasers. 1-x8 Ga x8 ) y5 In 1-y5 The thickness of the first upper confinement layer is 0.05-0.25 μm, 0≤x8≤0.3, 0.4≤y5≤0.6, and the doping concentration is 5E17-1E18 atoms / cm 3 , doping element is Mg; (Al 1-x10 Ga x10 ) y6 In 1-y6 The thickness of the second upper confinement layer is 0.5~1.2μm, 0.15≤x10≤0.3, 0.4≤y6≤0.48, and the doping concentration is 5E17~1.5E18 atoms / cm 3 , the doping element is Mg.

4. The low-power AlGaInP red semiconductor laser with optimized packaging stress by limiting layer strain according to claim 1, It is characterized in that The optimized confinement layer doped low-power AlGaInP red semiconductor laser includes one or more of the following conditions: ①. The buffer layer is a GaAs buffer layer, and the doping concentration of the GaAs buffer layer is 2E18~5E18 atoms / cm 3 , thickness is 0.1~0.3μm, and the doping element is Si; ②. The lower transition layer is Ga 1-x1 In x1 P lower transition layer, Ga 1-x1 In x1 The doping concentration of the P lower transition layer is 1E18-3E18 atoms / cm 3 , thickness is 0.1~0.3μm; 0.45≤x1≤0.55, doping element is Si; ③. The lower limiting layer is n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 P lower confinement layer, n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 The thickness of the P lower confinement layer is 0.5~1.5μm, and the doping concentration is 5E17~3E18 atoms / cm 3 , the doping element is Si; ④. The gradient lower waveguide layer is (Al 1-x3 Ga x3 ) y2 In 1-y2 P graded lower waveguide layer, (Al 1-x3 Ga x3 ) y2 In 1-y2 The thickness of the waveguide layer under the P gradient is 0.05~0.15μm, unintentionally doped, 0.05≤x3≤0.6, 0.4≤y2≤0.6; ⑤. The first quantum well is Ga 1-x4 In x4 P first quantum well, Ga 1-x4 In x4 The thickness of the first quantum well of P is 4~7nm, unintentionally doped, 0.3≤x4≤0.7; ⑥. The barrier layer is (Al 1-x5 Ga x5 ) y3 In 1-y3 P barrier layer, (Al 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the P barrier layer is 5~15nm, unintentionally doped, 0.25≤x5≤0.7, 0.4≤y3≤0.6; ⑦. The second quantum well is Ga 1-x6 In x6 P second quantum well, Ga 1-x6 In x6 The thickness of the second quantum well P is 4~7nm, unintentionally doped, 0.3≤x6≤0.7; ⑧. The gradient upper waveguide layer is (Al 1-x7 Ga x7 ) y4 In 1-y4 P graded upper waveguide layer, (Al 1-x7 Ga x7 ) y4 In 1-y4 The thickness of the P gradient upper waveguide layer is 0.05~0.15μm, and one-half of it close to the first upper confinement layer is doped with 0.05≤x7≤0.6, 0.4≤y4≤0.6, and the doping element is Mg; ⑨. Etch stop layer is P-type Ga 1-x9 In x9 P etching stop layer, P-type Ga 1-x9 In x9 The thickness of the P corrosion stop layer is 0.01~0.05μm, and the doping concentration is 5E17~2E18 atoms / cm 3 , 0.4≤x9≤0.6, the doping element is Mg; ⑩. The upper transition layer is P-type Ga 1-x11 In x11 P upper transition layer, P-type Ga 1-x11 In x11 The thickness of the transition layer on P is 0.01~0.05μm, and the doping concentration is 1E18~3E18 atoms / cm 3 , 0.4≤x11≤0.6, the doping element is Mg; ⑪. The cap layer is GaAs cap layer, the thickness of GaAs cap layer is 0.1~0.5μm, and the doping concentration is 4E19~1E20 atoms / cm 3 , the doping element is C.

5. The low-power AlGaInP red semiconductor laser with optimized packaging stress by limiting layer strain according to claim 1, It is characterized in that The optimized confinement layer doped low-power AlGaInP red semiconductor laser includes one or more of the following conditions: ①. The buffer layer is a GaAs buffer layer, and the doping concentration of the GaAs buffer layer is 4E18 atoms / cm 3 , thickness is 0.2μm, doping element is Si; ②. The lower transition layer is Ga 1-x1 In x1 P lower transition layer, Ga 1-x1 In x1 The doping concentration of the P lower transition layer is 2E18 atoms / cm 3 , x1=0.5, thickness is 0.1μm, doping element is Si; ③. The lower limiting layer is n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 P lower confinement layer, n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 The thickness of the P lower confinement layer is 1.2 μm, x2=0, y1=0.5, and the doping concentration is 1E18 atoms / cm 3 , the doping element is Si; ④. The gradient lower waveguide layer is (Al 1-x3 Ga x3 ) y2 In 1-y2 P graded lower waveguide layer, (Al 1-x3 Ga x3 ) y2 In 1-y2 The thickness of the waveguide layer under the P gradient is 0.08 μm, it is not intentionally doped, x3 gradients from 0.05 to 0.55, y2=0.5; ⑤. The first quantum well is Ga 1-x4 In x4 P first quantum well, Ga 1-x4 In x4 The thickness of the first quantum well of P is 5nm, it is not intentionally doped, and x4=0.4; ⑥. The barrier layer is (Al 1-x5 Ga x5 ) y3 In 1-y3 P barrier layer, (Al 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the P barrier layer is 6 nm, unintentionally doped, x5=0.5, y3=0.5; ⑦. The second quantum well is Ga 1-x6 In x6 P second quantum well, Ga 1-x6 In x6 The thickness of the second quantum well of P is 5nm, it is not intentionally doped, and x6=0.4; ⑧. The gradient upper waveguide layer is (Al 1-x7 Ga x7 ) y4 In 1-y4 P graded upper waveguide layer, (Al 1-x7 Ga x7 ) y4 In 1-y4 The thickness of the P gradient upper waveguide layer is 0.08 μm, x7 gradients from 0.5 to 0.05, y2 = 0.5, and the doping concentration is 4E17 atoms / cm 3 , the doping element is Mg; ⑨. Etch stop layer is P-type Ga 1-x9 In x9 P etching stop layer, P-type Ga 1-x9 In x9 The thickness of the P corrosion stop layer is 0.01 μm, x9=0.6, and the doping concentration is 1E18 atoms / cm 3 , the doping element is Mg; ⑩. The upper transition layer is P-type Ga 1-x11 In x11 P upper transition layer, P-type Ga 1-x11 In x11 The thickness of the transition layer on P is 0.01 μm, x11=0.5, and the doping concentration is 2E18 atoms / cm 3 , the doping element is Mg; ⑪. The cap layer is GaAs cap layer, the thickness of GaAs cap layer is 0.2μm, and the doping concentration is 7E19 atoms / cm 3 , the doping element is C.

6. A method for preparing a low-power AlGaInP red semiconductor laser with limited layer strain and optimized packaging stress. It is characterized in that The method comprises the following steps: performing surface heat treatment on the substrate in the MOCVD growth chamber, and then epitaxially growing a buffer layer, a lower transition layer, a lower confinement layer, a gradient lower waveguide layer, a first quantum well, a barrier layer, a second quantum well, a gradient upper waveguide layer, (Al 1-x8 Ga x8 ) y5 In 1-y5 P first upper limiting layer, corrosion stop layer, (Al 1-x10 Ga x10 ) y6 In 1-y6 P second upper limiting layer, upper transition layer and cap layer; Among them, the (Al 1-x8 Ga x8 ) y5 In 1-y5 The thickness of the first upper confinement layer is 0.05-0.25 μm, 0≤x8≤0.3, 0.4≤y5≤0.6, and the doping concentration is 5E17-1E18 atoms / cm 3 , doping element is Mg; (Al 1-x10 Ga x10 ) y6 In 1-y6 The thickness of the second upper confinement layer is 0.5~1.2μm, 0.15≤x10≤0.3, 0.4≤y6≤0.48, and the doping concentration is 5E17~1.5E18 atoms / cm 3 , the doping element is Mg; The (Al 1-x8 Ga x8 ) y5 In 1-y5 P first upper confinement layer and (Al 1-x10 Ga x10 ) y6 In 1-y6 The growth conditions of the second upper confinement layer of P are: growth temperature 690-710℃, introduction of TMAl, TMIn, TMGa and PH 3 .

7. A method for preparing a low-power AlGaInP red semiconductor laser with limited layer strain and optimized packaging stress. It is characterized in that The method comprises the following steps: S1, place the GaAs substrate in the growth chamber of the MOCVD equipment, H 2 The environment temperature was raised to 720±10℃ and baked, and AsH 3 , performing surface heat treatment on the GaAs substrate; S2, slowly lower the temperature to 680±10℃, with a cooling rate of no less than 30℃ / min, and continue to introduce TMGa and AsH 3 , growing a GaAs buffer layer on a GaAs substrate; Wherein, the doping concentration of the GaAs transition layer is 2E18~5E18 atoms / cm 3 , thickness is 0.1~0.3μm; S3, the temperature is maintained at 680±10℃, TMGa, TMIn and PH are introduced 3 , Ga is grown on the GaAs transition layer 1-x1 In x1 P lower transition layer; Among them, the Ga 1-x1 In x1 The doping concentration of the P gradient lower transition layer is 1E18~3E18 atoms / cm 3 , thickness is 0.1~0.3μm, 0.45≤x1≤0.55; S4, the temperature is slowly changed to 700±10℃, the heating rate is not more than 60℃ / min, and TMAl, TMIn, TMGa and PH are introduced. 3 , grow n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 P lower limiting layer; Wherein, the n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 The thickness of the P lower confinement layer is 0.5~1.5μm, and the doping concentration is 5E17~3E18 atoms / cm 3 , 0≤x2≤0.3, 0.4≤y1≤0.6; S5, the temperature is slowly changed to 650±10℃, and TMAl, TMIn, TMGa and PH are introduced. 3 , grown on the lower confinement layer (Al 1- x3 Ga x3 ) y2 In 1-y2 P gradient lower waveguide layer; Among them, the (Al 1-x3 Ga x3 ) y2 In 1-y2 The thickness of the P gradient waveguide layer is 0.05-0.15 μm, unintentionally doped, 0.05≤x3≤0.6, 0.4≤y2≤0.6; S6, the temperature is maintained at 650±10℃, and TMIn, TMGa and PH are continuously introduced. 3 , Ga is grown on the graded lower waveguide layer 1-x4 In x4 P first quantum well; Among them, the Ga 1-x4 In x4 The thickness of the first quantum well of P is 4~7nm, unintentionally doped, 0.3≤x4≤0.7; S7, the temperature is maintained at 650±10℃, TMAl, TMIn, TMGa and PH are introduced 3 , grown on the first quantum well (Al 1-x5 Ga x5 ) y3 In 1-y3 P barrier layer; Among them, the (Al 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the P barrier layer is 5~15nm, unintentionally doped, 0.25≤x5≤0.7, 0.4≤y3≤0.6; S8, the temperature is maintained at 650±10℃, and TMIn, TMGa and PH are continuously introduced. 3 , Ga is grown on the barrier layer 1-x6 In x6 P second quantum well; Among them, the Ga 1-x6 In x6 The thickness of the second quantum well P is 4~7nm, unintentionally doped, 0.3≤x6≤0.7; S9, the temperature is slowly changed to 700±10℃, and TMAl, TMIn, TMGa and PH are continuously introduced. 3 , grown on the second quantum well (Al 1-x7 Ga x7 ) y4 In 1-y4 P graded upper waveguide layer; Among them, the (Al 1-x7 Ga x7 ) y4 In 1-y4 The thickness of the P graded upper waveguide layer is 0.05~0.15μm, and half of it close to the first upper confinement layer is doped with 0.05≤x7≤0.6, 0.4≤y4≤0.6; S10, the temperature is maintained at 700±10℃, and TMIn, TMAl, TMGa and PH are continuously introduced. 3 , grow a P-type (Al 1-x8 Ga x8 ) y5 In 1-5 P first upper limiting layer; Among them, the P type (Al 1-x8 Ga x8 ) y5 In 1-y5 The thickness of the first upper confinement layer is 0.05~0.25μm, and the doping concentration is 5E17~1E18 atoms / cm 3 , 0≤x8≤0.3, 0.4≤y5≤0.6; S11, the temperature is maintained at 700±10℃, and TMIn, TMGa and PH are continuously introduced. 3 , grow P-type Ga on the first upper confinement layer 1-x9 In x9 P corrosion stop layer; Wherein, the P-type Ga 1-x9 In x9 The thickness of the P corrosion stop layer is 0.01~0.05μm, and the doping concentration is 5E17~1.2E18 atoms / cm 3 , 0.4≤x9≤0.6; S12, the temperature is maintained at 700±10℃, and TMIn, TMAl, TMGa and PH are continuously introduced. 3 , grow a P-type (Al 1-x10 Ga x10 ) y6 In 1-y6 P second upper limiting layer; Among them, the P type (Al 1-x10 Ga x10 ) y6 In 1-y6 The thickness of the second upper confinement layer is 0.5~1.2μm, and the doping concentration is 5E17~1.5E18 atoms / cm 3 , 0.15≤x10≤0.3, 0.4≤y6≤0.48; S13, the temperature gradually changes to 680±10℃, and TMGa and AsH 3 and PH 3 In the P-type (Al 1-x10 Ga x10 ) y6 In 1-y6 Ga is grown on the second upper confinement layer 1-x11 In x11 P upper transition layer; Wherein, the P-type Ga 1-x11 In x11 The thickness of the transition layer on P is 0.01~0.05μm, and the doping concentration is 1E18~3E18 atoms / cm 3 , 0.4≤x11≤0.6; S14, lower the temperature to 540±10℃, continue to introduce TMGa and AsH 3 , a GaAs cap layer is grown on the upper transition layer The thickness of the cap layer is 0.1-0.5 μm, and the doping concentration is 4E19-1E20 atoms / cm 3 .

8. The method for preparing a low-power AlGaInP red semiconductor laser with optimized packaging stress by limiting layer strain according to claim 7, It is characterized in that In step S2, the thickness of the GaAs transition layer is 0.2 μm and the doping concentration is 4E18 atoms / cm 3 ; In step S3, the Ga 1-x1 In x1 The thickness of the transition layer under the P gradient is 0.1 μm, x1=0.5, and the doping concentration is 2E18 atoms / cm 3 ; In step S4, the n-type (Al 1-x2 Ga x2 ) y1 In 1-y1 The thickness of the P lower confinement layer is 1.2 μm, x2=0, y1=0.5, and the doping concentration is 1E18 atoms / cm 3 ; In steps S2 to S4, the dopant is Si.

9. The method for preparing a low-power AlGaInP red semiconductor laser with optimized packaging stress by limiting layer strain according to claim 7, It is characterized in that In step S5, the (Al 1-x3 Ga x3 ) y2 In 1-y2 The thickness of the waveguide layer under the P gradient is 0.08μm x3 gradients from 0.05 to 0.55, y2=0.5; In step S6, the Ga 1-x4 In x4 The thickness of the first quantum well P is 5nm, x4=0.4; In step S7, the (Al 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the P barrier layer is 6 nm, x5=0.5, y3=0.5; In step S8, the Ga 1-x6 In x6 The thickness of the second quantum well P is 5nm, x6=0.4; In step S9, the (A1 1-x7 Ga x7 ) y4 In 1-y4 The thickness of the P-graded upper waveguide layer is 0.08 μm, and the doping concentration is 4E17 atoms / cm 3 , x7 gradually changes from 0.5 to 0.05, y2=0.

5.

10. The method for preparing a low-power AlGaInP red semiconductor laser with optimized packaging stress by limiting layer strain according to claim 7, It is characterized in that In step S10, the P-type (Al 1-x8 Ga x8 ) y5 In 1-y5 The thickness of the first upper confinement layer is 0.15 μm, and the doping concentration is 6E17 atoms / cm 3 , x8=0, y5=0.5; In step S11, the P-type Ga 1-x9 In x9 The thickness of the P corrosion stop layer is 0.01 μm and the doping concentration is 1E18 atoms / cm 3 , x9=0.6; In step S12, the P-type (Al 1-x10 Ga x10 ) y6 In 1-y6 The thickness of the second upper confinement layer is 0.7 μm, and the doping concentration is 8E17 atoms / cm 3 , x10=0.25, y6=0.45; In step S13, the P-type Ga 1-x11 In x11 The thickness of the transition layer on P is 0.01 μm, and the doping concentration is 2E18 atoms / cm 3 , x11=0.5; In step S14, the cap layer has a thickness of 0.2 μm and a doping concentration of 7E19 atoms / cm 3 ; The dopant in steps S9 to S13 is Mg, and the dopant in step S14 is C.

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