808nm semiconductor laser epitaxial wafer with linear gradient Al component double-waveguide structure and preparation method of 808nm semiconductor laser epitaxial wafer

Abstract

The invention relates to an 808nm semiconductor laser epitaxial wafer with a linear gradient Al component double-waveguide structure and a preparation method thereof. The 808nm semiconductor laser epitaxial wafer comprises an Al (x2-x3) Ga1-(x2-x3) As Al component linear gradient N outer waveguide layer, an Al (x4-x5) Ga1-(x4-x5) As Al component linear gradient N inner waveguide layer, an In < x6Ga < 1-x > 6As quantum well, a GaAsy1P1-y1 barrier layer, an Al (x7-x8) Ga1-(x7-x8) As Al component linear gradient P inner waveguide layer, an Al (x9-x10) Ga1-(x9-x10) As Al component linear gradient P outer waveguide layer, an Al < x11Ga < 1-x > 11As P limiting layer and a GaAs The overall photoelectric property of the device is improved.

Description

Technical Field

[0001] The invention relates to an 808nm semiconductor laser epitaxial wafer with a linear gradient Al component double waveguide structure and a preparation method thereof, belonging to the technical field of optoelectronics. Background Art

[0002] After years of development, GaAs-based 808nm high-power semiconductor lasers have the advantages of high power, small size, and long life. They are now widely used in important fields such as pump sources of solid-state lasers, advanced industrial production and processing, laser communications, medical cosmetology, automatic control, and military weapons. In recent years, high-power laser diodes (LDs) have been greatly improved in performance and have been widely used in fiber lasers, solid-state lasers, infrared lighting, and other fields. However, there are still key problems such as high carrier loss and high non-radiative recombination. In addition, it is difficult for LDs to obtain high power and conversion efficiency at high injection currents, which limits the further expansion of their application areas.

[0003] The Al component design in the epitaxial layer can control the carrier transmission and light field distribution in the waveguide and confinement layer. As a key functional layer, the waveguide structure can reduce carrier loss and non-radiative recombination, thereby improving the output power and photoelectric conversion efficiency. The document Chin.J.Lasers, 41, 0402003 (2014) designed a refractive index gradient waveguide structure LD. Due to the improvement of carrier injection efficiency and the optimization of band interface discontinuity between each epitaxial layer, the photoelectric conversion efficiency reached 76%. However, when the injection current increases, the electro-optical conversion efficiency decreases significantly due to the increase in carrier leakage and non-radiative recombination. The document ICOM, 47 (2015) reported a single waveguide structure with a reverse Al component gradient for expanding the light field distribution. Although the threshold current and carrier concentration are reduced, the output power and peak conversion efficiency are lower than those of traditional large optical cavity structures. At present, the mechanism of the influence of Al component gradient composite waveguide on the photoelectric performance of LD still needs further study. How to reduce carrier loss and non-radiative recombination under high injection current by designing new waveguide structures to achieve high output power and electro-optical conversion efficiency remains a difficult problem to be solved. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a high-power 808nm LD epitaxial wafer structure with an Al composition gradient dual-waveguide structure and a preparation method thereof.

[0005] The core technology of the present invention is to design a new type of double waveguide structure, in which the inner waveguide aluminum component adopts an inverse gradient distribution and the outer waveguide aluminum component adopts a positive gradient distribution. Compared with a single waveguide layer with a structure without an Al component gradient, the double waveguide layer structure with an inverse Al component gradient from the N side to the P side can reduce the injection barrier of electrons and holes by controlling the energy band offset and interface mutation, and has a higher blocking leakage barrier, thereby improving carrier transmission and leakage, reducing non-radiative recombination and carrier loss, and at the same time strengthening the optical confinement ability of the waveguide layer, concentrating the light field in the active area, thereby improving the output power and photoelectric conversion efficiency.

[0006] The invention utilizes MOCVD technology to grow AlGaAs material on GaAs substrate, and the AlGaAs material comprises, from bottom to top, GaAs substrate, GaAs buffer layer, Alx1Ga1-x1As N limiting layer, Al(x2-x3)Ga1-(x2-x3)As Al component linear gradient N outer waveguide layer, Al(x4-x5)Ga1-(x4-x5)As Al component linear gradient N inner waveguide layer, Inx6Ga1-x6As quantum well, GaAsy1P1-y1 barrier layer, Al(x7-x8)Ga1-(x7-x8)As Al component linear gradient P inner waveguide layer, Al(x9-x10)Ga1-(x9-x10)As Al component linear gradient P outer waveguide layer, Alx11Ga1-x11As P limiting layer, GaAs ohmic contact layer; the present invention designs a dual waveguide structure with different Al component linear gradients. The anti-Al component gradient waveguide can reduce the injection barrier of electrons and holes, and has a higher blocking leakage barrier. By controlling the energy band offset, the barrier height and interface mutation can be adjusted, thereby improving carrier transmission and leakage, so as to achieve high output power and photoelectric conversion efficiency, and improve the overall photoelectric performance of the device.

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

[0008] A high-power 808nm LD epitaxial wafer structure with an Al component gradient double waveguide structure, comprising, from bottom to top, a GaAs substrate, a GaAs buffer layer, an Alx1Ga1-x1As N limiting layer, an Al(x2-x3)Ga1-(x2-x3)As Al component linear gradient N outer waveguide layer, an Al(x4-x5)Ga1-(x4-x5)As Al component linear gradient N inner waveguide layer, an Inx6Ga1-x6As quantum well, a GaAsy1P1-y1 barrier layer, an Al(x7-x8)Ga1-(x7-x8)As Al component linear gradient P inner waveguide layer, an Al(x9-x10)Ga1-(x9-x10)As Al component linear gradient P outer waveguide layer, an Alx11Ga1-x11As P limiting layer, and a GaAs ohmic contact layer;

[0009] 0.3≤x1≤0.6, 0.3≤x2≤0.5, 0.3≤x3≤0.5, 0.3≤x4≤0.5, 0.3≤x5≤0.5, 0.2≤x6≤0.3, 0.5≤y1≤0.7, 0.3≤x7≤0.5, 0.3≤x8≤0.5, 0.3≤x9≤0.5, 0.3≤x10≤0.5, 0.3≤x11≤0.6.

[0010] Preferably according to the present invention, x1=0.55, x2=0.4, x3=0.47, x4=0.47, x5=0.4, x6=0.25, y1=0.6, x7=0.4, x8=0.47, x9=0.47, x10=0.4, x11=0.55.

[0011] The method for preparing the high-power 808nm LD epitaxial wafer structure having the Al composition gradient dual waveguide structure comprises:

[0012] (1) Growing a GaAs buffer layer and an Alx1Ga1-x1As N confinement layer in sequence on a GaAs substrate;

[0013] (2) introducing TMAl, TMGa and AH3 to grow an Al(x2~x3)Ga1-(x2~x3)As Al composition linear gradient N outer waveguide layer on the Alx1Ga1-x1As N confinement layer;

[0014] (3) maintaining the temperature at 660-680°C, introducing TMAl, TMGa and AH3 to grow an Al(x4-x5)Ga1-(x4-x5)As Al composition linear gradient N inner waveguide layer;

[0015] (4) sequentially growing Inx6Ga1-x6As quantum well and GaAsy1P1-y1 barrier layer on the Al(x4~x5)Ga1-(x4~x5)As Al composition linear gradient N inner waveguide layer;

[0016] (5) maintaining the temperature at 660-680°C, introducing TMAl, TMGa, and AH3, and growing an Al(x7-x8)Ga1-(x7-x8)AsAl composition linear gradient P inner waveguide layer on the GaAsy1P1-y1 barrier layer;

[0017] (6) maintaining the temperature at 660-680°C, introducing TMAl, TMGa, and AH3, and growing an Al(x9-x10)Ga1-(x9-x10)AsAl composition linear gradient P outer waveguide layer on the Al(x7-x8)Ga1-(x7-x8)AsAl composition linear gradient P inner waveguide layer;

[0018] (7) An Alx11Ga1-x11As P confinement layer and a GaAs ohmic contact layer are sequentially grown on the Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer.

[0019] Preferably, according to the present invention, in step (1), a GaAs buffer layer and an Alx1Ga1-x1As N confinement layer are sequentially grown on a GaAs substrate; comprising:

[0020] 1) Place the GaAs substrate in the growth chamber of the MOCVD equipment, heat the H2 environment to 710-730°C and bake for 20-40 minutes, then introduce AsH3 to perform high-temperature heat treatment on the GaAs substrate to remove water and oxygen on the substrate surface;

[0021] 2) Control the temperature of the growth chamber of the MOCVD equipment to slowly drop to 660-680°C, with a cooling rate not higher than 30°C / min, introduce TMGa and AsH3, and grow a GaAs buffer layer with a thickness of 100-300nm on the GaAs substrate;

[0022] 3) The temperature of the growth chamber of the MOCVD equipment is maintained at 660-680° C., TMAl, TMGa and AH3 are introduced, and an Alx1Ga1-x1As N confinement layer with a thickness of 1-1.3 um is grown on the GaAs buffer layer.

[0023] Preferably, according to the present invention, the specific implementation process of step (4) includes:

[0024] 4) The temperature of the MOCVD equipment growth chamber is reduced to 610-630°C, and TMGa, TMIn and AsH3 are introduced to grow Inx6Ga1-x6As quantum wells with a thickness of 5-10nm, without intentional doping;

[0025] 5) The temperature of the growth chamber of the MOCVD equipment is increased to 660-680°C, and TMGa, PH3 and AsH3 are introduced to grow a GaAsy1P1-y1 barrier layer with a thickness of 5-10nm.

[0026] Preferably, in step (7), an Alx11Ga1-x11As P confinement layer and a GaAs ohmic contact layer are sequentially grown on the Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer; comprising:

[0027] 6) The temperature of the growth chamber of the MOCVD equipment is maintained at 660-680°C, and TMAl, TMGa, and AsH3 are introduced to grow an Alx11Ga1-x11As P confinement layer with a thickness of 0.7-1um on the Al(x9-x10)Ga1-(x9-x10)As Al composition linear gradient P outer waveguide layer;

[0028] 7) The temperature of the growth chamber of the MOCVD equipment is reduced to 540-560°C, TMGa and AsH3 are introduced, and a GaAs ohmic contact layer with a thickness of 100-300 nm is grown on the Alx11Ga1-x11AsP confinement layer.

[0029] Further preferably, in step 1), the high temperature heat treatment temperature is 720° C. and the baking time is 30 minutes.

[0030] Further preferably, in step 2), the temperature of the growth chamber of the MOCVD equipment is 670° C., the growth thickness is 200 nm, and the doping concentration is 1E18-5E18 atoms / cm 3 .

[0031] Most preferably, in step 2), the doping concentration is 2E18 atoms / cm3, and the doping source is Si2H6.

[0032] Further preferably, in step 3), the temperature of the growth chamber of the MOCVD equipment is 670° C., the growth thickness is 1 um, 0.3≤x1≤0.6, and the doping concentration is 2E18-2E19 atoms / cm 3 .

[0033] Most preferably, in step 3), x1=0.55, the doping concentration is 1E19 atoms / cm3, and the doping source is Si2H6.

[0034] Preferably, according to the present invention, in step (2), the temperature of the growth chamber of the MOCVD equipment is maintained at 660-680°C, and the thickness of the grown Al(x2~x3)Ga1-(x2~x3)As Al composition linear gradient N outer waveguide layer is 0.2-0.4um.

[0035] Further preferably, in step (2), the temperature of the growth chamber of the MOCVD equipment is 670°C, the thickness of the grown Al(x2~x3)Ga1-(x2~x3)As Al component linear gradient N outer waveguide layer is 0.3um, and the Al component gradient of the grown Al(x2~x3)Ga1-(x2~x3)As Al component linear gradient N outer waveguide layer has an Al component gradient, and the doping concentration is 4E17-4E18 atoms / cm3.

[0036] Most preferably, in step (2), x2=0.4, x3=0.47, the doping concentration is 1E18 atoms / cm3, and the doping source is Si2H6.

[0037] Preferably, in step (3), the thickness of the grown Al(x4~x5)Ga1-(x4~x5)As Al composition linear gradient N inner waveguide layer is 0.2-0.4um; x4=0.47, x5=0.4;

[0038] Further preferably, in step (3), the temperature of the growth chamber of the MOCVD equipment is 670°C, the thickness of the grown Al(x4~x5)Ga1-(x4~x5)As Al component linear gradient N inner waveguide layer is 0.3um, the Al component gradient is graded, and the N inner waveguide is not intentionally doped.

[0039] Further preferably, in step 4), the temperature of the growth chamber of the MOCVD equipment is 620° C., the growth thickness is 7 nm, and x6=0.25.

[0040] Further preferably, in step 5), the temperature of the growth chamber of the MOCVD equipment is 670° C., the growth thickness is 8 nm, and y1=0.6.

[0041] Preferably according to the present invention, in step (5), the thickness of the grown Al(x7~x8)Ga1-(x7~x8)As Al composition linear gradient P inner waveguide layer is 0.1-0.3um and is not intentionally doped.

[0042] Further preferably, in step (5), the temperature of the growth chamber of the MOCVD equipment is 670°C, the thickness of the grown Al(x7~x8)Ga1-(x7~x8)As Al component linear gradient P inner waveguide layer is 0.15um, and the Al component gradient of the Al(x7~x8)Ga1-(x7~x8)AsAl component linear gradient P inner waveguide layer is gradated.

[0043] Most preferably, x7=0.4, x8=0.47.

[0044] Preferably, according to the present invention, in step (6), the thickness of the grown Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer is 0.1-0.3um, and the doping concentration is 1E17-3E17 atoms / cm3.

[0045] Further preferably, in step (6), the temperature is maintained at 670°C, the growth thickness is 0.15um, x9=0.47, x10=0.4, Al(x9~x10)Ga1-(x9~x10)As Al component linear gradient P outer waveguide layer has Al component gradient grading, the doping concentration is 2E17 atoms / cm3, and the doping source is CBr4.

[0046] Further preferably, in step 6), the temperature of the growth chamber of the MOCVD equipment is 670° C., the thickness of the grown Alx11Ga1-x11AsP confinement layer is 0.8 um, and the doping concentration is 2E18-2E19 atoms / cm3.

[0047] Further preferably, in step 6), x11=0.55, the doping concentration is 1E19 atoms / cm3, and the doping source is CBr4.

[0048] Further preferably, in step 7), the temperature of the growth chamber of the MOCVD equipment is 550° C., the growth thickness is 200 nm, and the doping concentration is 9E18-5E19 atoms / cm 3 .

[0049] Further preferably, in step 7), the doping concentration is 4E19 atoms / cm3, and the doping source is CBr4.

[0050] The beneficial effects of the present invention are:

[0051] The present invention designs a dual waveguide structure with different linear gradients of Al components. The anti-Al component gradient waveguide can reduce the injection barrier of electrons and holes, and has a higher barrier to block leakage. By controlling the energy band offset to adjust the barrier height and interface mutation, carrier transmission is optimized, and carrier leakage and waste heat generation are reduced. In addition, the Al component gradient distribution of the waveguide layer strengthens the optical confinement ability of the waveguide layer, concentrates the light field in the active area, reduces the light field loss, and further improves the overall optoelectronic performance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 Schematic diagram of the structure of a high-power 808nm LD epitaxial wafer according to an embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram of the structure of a conventional high-power 808nm LD epitaxial wafer;

[0054] 1. GaAs substrate, 2. GaAs buffer layer, 3. Alx1Ga1-x1As N confinement layer, 4. Al(x2~x3)Ga1-(x2~x3)As Al composition linear gradient N outer waveguide layer, 5. Al(x4~x5)Ga1-(x4~x5)As Al composition linear gradient N inner waveguide layer, 6. Inx6Ga1-x6As quantum well, 7. GaAsy1P1-y1 barrier layer, 8. Al(x7~x8)Ga1-(x7~x8)As Al composition linear gradient P inner waveguide layer, 9. Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer, 10. Alx11Ga1-x11As P confinement layer, 11. GaAs ohmic contact layer. DETAILED DESCRIPTION

[0055] The present invention will be further defined below in conjunction with the accompanying drawings and embodiments, but is not limited thereto.

[0056] Example 1

[0057] A high-power 808nm LD epitaxial wafer structure with an Al composition gradient dual waveguide structure, such as Figure 1 As shown, it includes, from bottom to top: GaAs substrate 1, GaAs buffer layer 2, Alx1Ga1-x1As N confinement layer 3, Al(x2~x3)Ga1-(x2~x3)As Al composition linear gradient N outer waveguide layer 4, Al(x4~x5)Ga1-(x4~x5)As Al composition linear gradient N inner waveguide layer 5, Inx6Ga1-x6As quantum well 6, GaAsy1P1-y1 barrier layer 7, Al(x7~x8)Ga1-(x7~x8)As Al composition linear gradient P inner waveguide layer 8, Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer 9, Alx11Ga1-x11As P confinement layer 10, and GaAs ohmic contact layer 11;

[0058] 0.3≤x1≤0.6, 0.3≤x2≤0.5, 0.3≤x3≤0.5, 0.3≤x4≤0.5, 0.3≤x5≤0.5, 0.2≤x6≤0.3, 0.5≤y1≤0.7, 0.3≤x7≤0.5, 0.3≤x8≤0.5, 0.3≤x9≤0.5, 0.3≤x10≤0.5, 0.3≤x11≤0.6.

[0059] Example 2

[0060] According to the high-power 808nm LD epitaxial wafer structure with an Al composition gradient dual waveguide structure described in Example 1, the difference is: x1=0.55, x2=0.4, x3=0.47, x4=0.47, x5=0.4, x6=0.25, y1=0.6, x7=0.4, x8=0.47, x9=0.47, x10=0.4, x11=0.55.

[0061] Example 3

[0062] The method for preparing the high-power 808nm LD epitaxial wafer structure having the Al composition gradient dual waveguide structure described in Embodiment 1 or 2 comprises:

[0063] (1) A GaAs buffer layer 2 and an Alx1Ga1-x1As N confinement layer 3 are sequentially grown on a GaAs substrate 1;

[0064] (2) introducing TMAl, TMGa and AH3 to grow an Al(x2~x3)Ga1-(x2~x3)AsAl composition linear gradient N outer waveguide layer 4 on the Alx1Ga1-x1AsN confinement layer 3;

[0065] (3) maintaining the temperature at 660-680°C, introducing TMAl, TMGa and AH3, and growing the Al(x4-x5)Ga1-(x4-x5)As Al composition linear gradient N inner waveguide layer 5;

[0066] (4) sequentially growing an Inx6Ga1-x6As quantum well 6 and a GaAsy1P1-y1 barrier layer 7 on an Al(x4~x5)Ga1-(x4~x5)As Al composition linear gradient N inner waveguide layer 5;

[0067] (5) maintaining the temperature at 660-680°C, introducing TMAl, TMGa, and AH3, and growing an Al(x7-x8)Ga1-(x7-x8)AsAl composition linear gradient P inner waveguide layer 8 on the GaAsy1P1-y1 barrier layer 7;

[0068] (6) maintaining the temperature at 660-680°C, introducing TMAl, TMGa, and AH3, and growing an Al(x9-x10)Ga1-(x9-x10)AsAl composition linear gradient P outer waveguide layer 9 on the Al(x7-x8)Ga1-(x7-x8)AsAl composition linear gradient P inner waveguide layer 8;

[0069] (7) An Alx11Ga1-x11As P confinement layer 10 and a GaAs ohmic contact layer 11 are sequentially grown on the Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer 9 to obtain.

[0070] Example 4

[0071] The method for preparing a high-power 808nm LD epitaxial wafer structure having an Al composition gradient dual waveguide structure according to Embodiment 3 comprises:

[0072] In step (1), a GaAs buffer layer 2 and an Alx1Ga1-x1As N confinement layer 3 are sequentially grown on a GaAs substrate 1; comprising:

[0073] 1) placing a GaAs substrate 1 in a growth chamber of an MOCVD device, heating the H2 environment to 710-730° C. and baking for 20-40 minutes, then introducing AsH3 to perform a high-temperature heat treatment on the GaAs substrate 1 to remove water and oxygen on the substrate surface;

[0074] 2) controlling the temperature of the growth chamber of the MOCVD equipment to slowly drop to 660-680° C., with a cooling rate of no more than 30° C. / min, introducing TMGa and AsH 3 to grow a GaAs buffer layer 2 with a thickness of 100-300 nm on the GaAs substrate 1;

[0075] 3) The temperature of the growth chamber of the MOCVD equipment is maintained at 660-680° C., TMAl, TMGa and AH3 are introduced, and an Alx1Ga1-x1As N confinement layer 3 with a thickness of 1-1.3 um is grown on the GaAs buffer layer 2.

[0076] The specific implementation process of step (4) includes:

[0077] 4) The temperature of the MOCVD equipment growth chamber is reduced to 610-630°C, and TMGa, TMIn and AsH3 are introduced to grow Inx6Ga1-x6As quantum well 6 with a thickness of 5-10nm, without intentional doping;

[0078] 5) The temperature of the growth chamber of the MOCVD equipment is increased to 660-680°C, and TMGa, PH3 and AsH3 are introduced to grow a GaAsy1P1-y1 barrier layer 7 with a thickness of 5-10 nm.

[0079] In step (7), an Alx11Ga1-x11As P confinement layer 10 and a GaAs ohmic contact layer 11 are sequentially grown on an Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer 9; comprising:

[0080] 6) The temperature of the growth chamber of the MOCVD equipment is maintained at 660-680°C, TMAl, TMGa, and AsH3 are introduced, and an Alx11Ga1-x11As P confinement layer 10 with a thickness of 0.7-1 um is grown on the Al(x9-x10)Ga1-(x9-x10)As Al composition linear gradient P outer waveguide layer 9;

[0081] 7) The temperature of the growth chamber of the MOCVD equipment is reduced to 540-560°C, TMGa and AsH3 are introduced, and a GaAs ohmic contact layer 11 with a thickness of 100-300 nm is grown on the Alx11Ga1-x11AsP confinement layer 10.

[0082] Example 5

[0083] The method for preparing a high-power 808nm LD epitaxial wafer structure having an Al composition gradient dual waveguide structure according to Embodiment 3 or 4 is different in that:

[0084] In step 1), the high temperature heat treatment temperature is 720° C. and the baking time is 30 minutes.

[0085] In step 2), the temperature of the growth chamber of the MOCVD equipment is 670° C., the growth thickness is 200 nm, and the doping concentration is 1E18-5E18 atoms / cm 3 .

[0086] In step 3), the temperature of the growth chamber of the MOCVD equipment is 670° C., the growth thickness is 1 um, and the doping concentration is 2E18-2E19 atoms / cm 3 .

[0087] In step (2), the temperature of the growth chamber of the MOCVD equipment is maintained at 660-680° C., and the thickness of the grown Al(x2~x3)Ga1-(x2~x3)As Al composition linear gradient N outer waveguide layer 4 is 0.2-0.4 um.

[0088] In step (3), the thickness of the grown Al(x4~x5)Ga1-(x4~x5)As Al composition linear gradient N inner waveguide layer 5 is 0.2-0.4um; x4=0.47, x5=0.4;

[0089] In step (5), the thickness of the grown Al(x7~x8)Ga1-(x7~x8)As Al composition linear gradient P inner waveguide layer 8 is 0.1-0.3 um and is not intentionally doped.

[0090] In step (6), the grown Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer 9 has a thickness of 0.1-0.3 um and a doping concentration of 1E17-3E17 atoms / cm3.

[0091] In step 6), the temperature of the growth chamber of the MOCVD equipment is 670° C., the thickness of the grown Alx11Ga1-x11AsP confinement layer 10 is 0.8 um, and the doping concentration is 2E18-2E19 atoms / cm3.

[0092] In step 7), the temperature of the growth chamber of the MOCVD equipment is 550° C., the growth thickness is 200 nm, and the doping concentration is 9E18-5E19 atoms / cm 3 .

[0093] Example 6

[0094] According to the method for preparing a high-power 808nm LD epitaxial wafer structure having an Al composition gradient dual waveguide structure as described in Example 3 or 4,

[0095] In step 2), the doping concentration is 2E18 atoms / cm3, and the doping source is Si2H6.

[0096] In step 3), x1=0.55, the doping concentration is 1E19 atoms / cm3, and the doping source is Si2H6.

[0097] In step (2), x2=0.4, x3=0.47, the doping concentration is 1E18 atoms / cm3, and the doping source is Si2H6.

[0098] In step (3), the temperature of the growth chamber of the MOCVD equipment is 670°C, the thickness of the grown Al(x4~x5)Ga1-(x4~x5)AsAl linear gradient N inner waveguide layer 5 is 0.3um, the Al composition is gradient graded, and the N inner waveguide is not intentionally doped.

[0099] In step 4), the temperature of the growth chamber of the MOCVD equipment is 620° C., the growth thickness is 7 nm, and x6=0.25.

[0100] In step 5), the temperature of the growth chamber of the MOCVD equipment is 670° C., the growth thickness is 8 nm, and y1=0.6.

[0101] In step (5), the temperature of the growth chamber of the MOCVD equipment is 670°C, the thickness of the grown Al(x7~x8)Ga1-(x7~x8)AsAl linear composition gradient P inner waveguide layer 8 is 0.15um, and the Al composition gradient of the Al(x7~x8)Ga1-(x7~x8)As Al linear composition gradient P inner waveguide layer 8 is x7=0.4, x8=0.47.

[0102] In step (6), the temperature is maintained at 670°C, the growth thickness is 0.15um, x9=0.47, x10=0.4, Al(x9~x10)Ga1-(x9~x10)As Al component linear gradient P, the Al component gradient in the outer waveguide layer 9, the doping concentration is 2E17 atoms / cm3, and the doping source is CBr4.

[0103] In step 6), x11=0.55, the doping concentration is 1E19 atoms / cm3, and the doping source is CBr4.

[0104] In step 7), the doping concentration is 4E19 atoms / cm3, and CBr4 is used as the doping source.

[0105] Figure 2 1 is a schematic diagram of the structure of a conventional high-power 808nm LD epitaxial wafer. Table 1 is a comparison of electrical parameters under the same process between the conventional structure and the structure of the laser device of the present invention.

[0106] Table 1

[0107]

[0108] As can be seen from Table 1, the threshold current of the present invention is low, the slope efficiency is high, and the output power is greater than that of conventional devices at the same current, indicating that the design of the present invention can effectively improve carrier transmission and reduce carrier loss, while strengthening the optical confinement ability of the waveguide layer, concentrating the light field in the active area, thereby improving the output power and photoelectric conversion efficiency.

Claims

1. A high-power 808nm LD epitaxial wafer structure with an Al composition gradient dual waveguide structure, characterized in that: The invention comprises, from bottom to top, a GaAs substrate, a GaAs buffer layer, an Alx1Ga1-x1As N limiting layer, an Al(x2~x3)Ga1-(x2~x3)AsAl composition linear gradient N outer waveguide layer, an Al(x4~x5)Ga1-(x4~x5)As Al composition linear gradient N inner waveguide layer, an Inx6Ga1-x6As quantum well, a GaAsy1P1-y1 barrier layer, an Al(x7~x8)Ga1-(x7~x8)As Al composition linear gradient P inner waveguide layer, an Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer, an Alx11Ga1-x11As P limiting layer, and a GaAs ohmic contact layer. 0.3≤x1≤0.6, 0.3≤x2≤0.5, 0.3≤x3≤0.5, 0.3≤x4≤0.5, 0.3≤x5≤0.5, 0.2≤x6≤0.3, 0.5≤y1≤0.7, 0.3≤x7≤0.5, 0.3≤x8≤0.5, 0.3≤x9≤0.5, 0.3≤x10≤0.5, 0.3≤x11≤0.

6.

2. The high-power 808nm LD epitaxial wafer structure with Al composition gradient dual waveguide structure according to claim 1, characterized in that: x1=0.55, x2=0.4, x3=0.47, x4=0.47, x5=0.4, x6=0.25, y1=0.6, x7=0.4, x8=0.47, x9=0.47, x10=0.4, x11=0.

55.

3. The method for preparing a high-power 808nm LD epitaxial wafer structure having an Al composition gradient dual waveguide structure according to claim 1 or 2, characterized in that: include: (1) Growing a GaAs buffer layer and an Alx1Ga1-x1As N confinement layer in sequence on a GaAs substrate; (2) introducing TMAl, TMGa and AH3 to grow an Al(x2~x3)Ga1-(x2~x3)As Al composition linear gradient N outer waveguide layer on the Alx1Ga1-x1As N confinement layer; (3) maintaining the temperature at 660-680°C, introducing TMAl, TMGa and AH3 to grow an Al(x4-x5)Ga1-(x4-x5)As Al composition linear gradient N inner waveguide layer; (4) sequentially growing Inx6Ga1-x6As quantum well and GaAsy1P1-y1 barrier layer on the Al(x4~x5)Ga1-(x4~x5)As Al composition linear gradient N inner waveguide layer; (5) maintaining the temperature at 660-680°C, introducing TMAl, TMGa, and AH3, and growing an Al(x7-x8)Ga1-(x7-x8)AsAl composition linear gradient P inner waveguide layer on the GaAsy1P1-y1 barrier layer; (6) maintaining the temperature at 660-680°C, introducing TMAl, TMGa, and AH3, and growing an Al(x9-x10)Ga1-(x9-x10)As Al composition linear gradient P outer waveguide layer on the Al(x7-x8)Ga1-(x7-x8)As Al composition linear gradient P inner waveguide layer; (7) An Alx11Ga1-x11As P confinement layer and a GaAs ohmic contact layer are sequentially grown on the Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer.

4. The method for preparing a high-power 808nm LD epitaxial wafer structure having an Al composition gradient dual waveguide structure according to claim 3, characterized in that: In step (1), a GaAs buffer layer and an Alx1Ga1-x1As N confinement layer are sequentially grown on a GaAs substrate; comprising: 1) Place the GaAs substrate in the growth chamber of the MOCVD equipment, heat the H2 environment to 710-730°C and bake for 20-40 minutes, then introduce AsH3 to perform high-temperature heat treatment on the GaAs substrate to remove water and oxygen on the substrate surface; 2) Control the temperature of the growth chamber of the MOCVD equipment to slowly drop to 660-680°C, with a cooling rate not higher than 30°C / min, introduce TMGa and AsH3, and grow a GaAs buffer layer with a thickness of 100-300nm on the GaAs substrate; 3) The temperature of the growth chamber of the MOCVD equipment is maintained at 660-680° C., TMAl, TMGa and AH3 are introduced, and an Alx1Ga1-x1As N confinement layer with a thickness of 1-1.3 μm is grown on the GaAs buffer layer; Further preferably, the specific implementation process of step (4) includes: 4) The temperature of the MOCVD equipment growth chamber is reduced to 610-630°C, and TMGa, TMIn and AsH3 are introduced to grow Inx6Ga1-x6As quantum wells with a thickness of 5-10nm, without intentional doping; 5) The temperature of the growth chamber of the MOCVD equipment is increased to 660-680°C, TMGa, PH3 and AsH3 are introduced, and a GaAsy1P1-y1 barrier layer with a thickness of 5-10nm is grown; Further preferably, in step (7), an Alx11Ga1-x11As P confinement layer and a GaAs ohmic contact layer are sequentially grown on the Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer; comprising: 6) The temperature of the growth chamber of the MOCVD equipment is maintained at 660-680°C, and TMAl, TMGa, and AsH3 are introduced to grow an Alx11Ga1-x11As P confinement layer with a thickness of 0.7-1um on the Al(x9-x10)Ga1-(x9-x10)As Al composition linear gradient P outer waveguide layer; 7) The temperature of the growth chamber of the MOCVD equipment is reduced to 540-560°C, TMGa and AsH3 are introduced, and a GaAs ohmic contact layer with a thickness of 100-300 nm is grown on the Alx11Ga1-x11AsP confinement layer.

5. The method for preparing a high-power 808nm LD epitaxial wafer structure having an Al composition gradient dual waveguide structure according to claim 4, characterized in that: In step 1), the high temperature heat treatment temperature is 720°C and the baking time is 30 minutes; In step 2), the temperature of the growth chamber of the MOCVD equipment is 670°C, the growth thickness is 200nm, and the doping concentration is 1E18-5E18 atoms / cm3; Further preferably, in step 2), the doping concentration is 2E18 atoms / cm3, and the doping source is Si2H6; Further preferably, in step 3), the temperature of the growth chamber of the MOCVD equipment is 670° C., the growth thickness is 1 um, 0.3≤x1≤0.6, and the doping concentration is 2E18-2E19 atoms / cm3; Most preferably, in step 3), x1=0.55, the doping concentration is 1E19 atoms / cm3, and the doping source is Si2H6.

6. The method for preparing a high-power 808nm LD epitaxial wafer structure having an Al composition gradient dual waveguide structure according to claim 4, characterized in that: In step (2), the temperature of the growth chamber of the MOCVD equipment is maintained at 660-680°C, and the thickness of the grown Al(x2-x3)Ga1-(x2-x3)As Al composition linear gradient N outer waveguide layer is 0.2-0.4 um; Further preferably, in step (2), the temperature of the growth chamber of the MOCVD equipment is 670°C, the thickness of the grown Al(x2~x3)Ga1-(x2~x3)As Al component linear gradient N outer waveguide layer is 0.3um, and the Al component gradient of the grown Al(x2~x3)Ga1-(x2~x3)AsAl component linear gradient N outer waveguide layer is 4E17-4E18 atoms / cm3; Most preferably, in step (2), x2=0.4, x3=0.47, the doping concentration is 1E18 atoms / cm3, and the doping source is Si2H6.

7. The method for preparing a high-power 808nm LD epitaxial wafer structure having an Al composition gradient dual waveguide structure according to claim 4, characterized in that: In step (3), the thickness of the grown Al(x4~x5)Ga1-(x4~x5)As Al composition linear gradient N inner waveguide layer is 0.2-0.4um; x4=0.47, x5=0.4; Further preferably, in step (3), the temperature of the growth chamber of the MOCVD equipment is 670°C, the thickness of the grown Al(x4~x5)Ga1-(x4~x5)As Al component linear gradient N inner waveguide layer is 0.3um, the Al component gradient is graded, and the N inner waveguide is not intentionally doped; Further preferably, in step 4), the temperature of the growth chamber of the MOCVD equipment is 620° C., the growth thickness is 7 nm, and x6=0.25; Further preferably, in step 5), the temperature of the growth chamber of the MOCVD equipment is 670° C., the growth thickness is 8 nm, and y1=0.

6.

8. The method for preparing a high-power 808nm LD epitaxial wafer structure having an Al composition gradient dual waveguide structure according to claim 4, characterized in that: In step (5), the thickness of the grown Al(x7~x8)Ga1-(x7~x8)As Al composition linear gradient P inner waveguide layer is 0.1-0.3 um and is not intentionally doped; Further preferably, in step (5), the temperature of the growth chamber of the MOCVD equipment is 670°C, the thickness of the grown Al(x7~x8)Ga1-(x7~x8)As Al component linear gradient P inner waveguide layer is 0.15um, and the Al component gradient of the Al(x7~x8)Ga1-(x7~x8)As Al component linear gradient P inner waveguide layer is 0.15um; Most preferably, x7=0.4, x8=0.

47.

9. The method for preparing a high-power 808nm LD epitaxial wafer structure having an Al composition gradient dual waveguide structure according to claim 4, characterized in that: In step (6), the thickness of the grown Al(x9~x10)Ga1-(x9~x10)As Al composition linear gradient P outer waveguide layer is 0.1-0.3um, and the doping concentration is 1E17-3E17 atoms / cm3; Further preferably, in step (6), the temperature is maintained at 670°C, the growth thickness is 0.15um, x9=0.47, x10=0.4, Al(x9~x10)Ga1-(x9~x10)As Al component linear gradient P outer waveguide layer has Al component gradient grading, the doping concentration is 2E17 atoms / cm3, and the doping source is CBr4.

10. The method for preparing a high-power 808nm LD epitaxial wafer structure having an Al composition gradient dual waveguide structure according to claim 4, characterized in that: In step 6), the temperature of the growth chamber of the MOCVD equipment is 670°C, the thickness of the grown Alx11Ga1-x11AsP confinement layer is 0.8um, and the doping concentration is 2E18-2E19 atoms / cm3; Further preferably, in step 6), x11=0.55, the doping concentration is 1E19 atoms / cm3, and the doping source is CBr4; Further preferably, in step 7), the temperature of the growth chamber of the MOCVD equipment is 550° C., the growth thickness is 200 nm, and the doping concentration is 9E18-5E19 atoms / cm3; Further preferably, in step 7), the doping concentration is 4E19 atoms / cm3, and the doping source is CBr4.

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