GaAs-based high-power laser epitaxial wafer with controllable mechanical stress structure and preparation method thereof

Abstract

A GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure and its fabrication method belong to the field of optoelectronic technology. This invention utilizes MOCVD technology to grow AlGaAs material on a GaAs substrate, with a GaAs buffer layer and an AlGaAs layer sequentially arranged from bottom to top on the GaAs substrate. x1 Ga 1‑x1 As N-confined layer, Al x2 Ga 1‑ x2 As z1 P 1‑z1 / Al x2 Ga 1‑x2 As the lower waveguide layer, In y1 Ga 1‑y1 As quantum well layer, Al x3 Ga 1‑x3 As z2 P 1‑z2 / Al x3 Ga 1‑x3 As upper waveguide layer, Al x4 Ga 1‑x4 AlGaAsP / AlGaAs is used as the waveguide layer, with a P-type confinement layer and a GaAs ohmic contact layer. This invention selects a periodic AlGaAsP / AlGaAs structure as the waveguide layer, controlling the lattice constants of the upper and lower waveguide layers by adjusting the amount of P-component, thus achieving stress adjustment in the AlGaAs epitaxial structure. The periodic AlGaAsP / AlGaAs structure also prevents the P-component in the waveguide layer from diffusing into the quantum well, affecting the growth quality of the quantum well. Furthermore, the thin P-type waveguide layer design reduces series resistance, shifting the optical field towards the N-side, reducing light absorption, and increasing output power. Directly releasing stress through the epitaxial structure is not only low-cost and simple to operate, but also suitable for mass production.

Description

Technical Field

[0001] This invention relates to a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure and its fabrication method, belonging to the field of optoelectronic technology. Background Technology

[0002] In recent years, with the continuous improvement of output power, semiconductor lasers have become increasingly widespread and dominant in applications. High-power semiconductor lasers are the pump sources for most high-performance laser systems, covering materials processing, optical communication, medical applications, laser printing, laser displays, and military and defense equipment. Although the output power and beam quality of semiconductor lasers have improved significantly in recent years, they still cannot meet the growing industrial demands. In particular, with the development of bar lasers with long cavities (3000-5000µm) and multiple emission points, improving beam quality is urgently needed.

[0003] Advances in long-wavelength lasers have driven the development of AlGaAs material systems, especially those with wavelengths above 900nm. Since AlGaAs cannot achieve epitaxial stress control through composition adjustment, special die processes are typically used to enhance optical confinement capabilities in order to improve the beam quality of bar lasers. While this method improves beam quality, it is not only cumbersome but also sacrifices some output power, which contradicts the ever-increasing power demands. Another approach is to improve beam quality by reducing packaging stress through improved solder and adding an external optical confinement module. Although this method retains high power and optimizes beam quality, its high cost makes it unsuitable for widespread application in large-scale products. The essence of beam quality degradation lies in the generation of mechanical stress within the bar. Finding a low-cost, high-efficiency method to reduce mechanical stress is crucial for the development of semiconductor laser devices. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a GaAs-based high-power laser epitaxial wafer structure with controllable mechanical stress and its fabrication method.

[0005] The core technology of this invention is that the waveguide layer adopts a periodic structure of AlGaAsP / AlGaAs similar to a superlattice. The difference between this invention and traditional superlattices and other patents that adopt periodic structures is that this invention forms a periodic structure of AlGaAsP / AlGaAs by adjusting the composition of P. By adjusting the lattice constant of AlGaAsP, the strain of the epitaxial structure can be adjusted.

[0006] This invention utilizes MOCVD technology to grow AlGaAs material on a GaAs substrate. The GaAs substrate includes, from bottom to top, a GaAs buffer layer and an AlGaAs layer.x1 Ga 1-x1 As N-confined layer, Al x2 Ga 1-x2 As z1 P 1-z1 / Al x2 Ga 1-x2 As the lower waveguide layer, In y1 Ga 1-y1 As quantum well layer, Al x3 Ga 1-x3 As z2 P 1-z2 / Al x3 Ga 1-x3 As upper waveguide layer, Al x4 Ga 1-x4 AlGaAsP / AlGaAs is used as the waveguide layer, with a P-type confinement layer and a GaAs ohmic contact layer. This invention selects a periodic AlGaAsP / AlGaAs structure as the waveguide layer, controlling the lattice constants of the upper and lower waveguide layers by adjusting the amount of P-component, thus achieving stress adjustment in the AlGaAs epitaxial structure. The periodic AlGaAsP / AlGaAs structure also prevents the P-component in the waveguide layer from diffusing into the quantum well, affecting the growth quality of the quantum well. Furthermore, the thin P-type waveguide layer design reduces series resistance, shifting the optical field towards the N-side, reducing light absorption, and increasing output power. Directly releasing stress through the epitaxial structure is not only low-cost and simple to operate, but also suitable for mass production.

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

[0008] A GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure comprises, from bottom to top, a GaAs substrate, a GaAs buffer layer, and an Al layer. x1 Ga 1-x1 As N-confining layer, lower waveguide layer, In y1 Ga 1-y1 As quantum well layer, upper waveguide layer, Al x4 Ga 1-x4 As P confinement layer, GaAs ohmic contact layer;

[0009] The lower waveguide layer includes periodically grown Al x2 Ga 1-x2 As z1 P 1-z1 Lower waveguide layer, Al x2 Ga 1-x2 As the lower waveguide layer;

[0010] The upper waveguide layer includes periodically grown Al x3 Ga 1-x3 As upper waveguide layer, Al x3 Ga 1-x3As z2 P 1-z2 Upper waveguide layer.

[0011] Preferably, a single layer of Al x2 Ga 1-x2 As z1 P 1-z1 Lower waveguide layer and one layer of Al x2 Ga 1-x2 As, the lower waveguide layer has one period, and the lower waveguide layer has a total of 8 periods.

[0012] Further preferred, Al x2 Ga 1-x2 As z1 P 1-z1 The thickness of the lower waveguide layer is 10-100 nm, Al x2 Ga 1-x2 The thickness of the lower waveguide layer is 10-100 nm; after 8 cycles of growth, the total thickness of the lower waveguide layer is 800 nm.

[0013] Preferably, a single layer of Al x3 Ga 1-x3 As upper waveguide layer and one layer of Al x3 Ga 1-x3 As z2 P 1-z2 The upper waveguide layer has one cycle, and there are a total of 4 cycles in the upper waveguide layer.

[0014] Further preferred, Al x3 Ga 1-x3 The thickness of the waveguide layer on As is 10-100 nm, Al x3 Ga 1-x3 As z2 P 1-z2 The thickness of the upper waveguide layer is 10-100 nm; after four growth cycles, the total thickness of the upper waveguide layer is 400 nm.

[0015] Preferably, the GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure includes one or more of the following conditions:

[0016] Ⅰ.Al x1 Ga 1-x1 In the As N-restricted layer, 0.3 ≤ x1 ≤ 0.5;

[0017] II.Al x2 Ga 1-x2 As z1 P 1-z1 In the lower waveguide layer, 0.1≤x2≤0.3, 0.95≤z1≤0.99;

[0018] Ⅲ.Al x2Ga 1-x2 In the waveguide layer below As, 0.1 ≤ x2 ≤ 0.3;

[0019] IV.In y1 Ga 1-y1 In the As quantum well layer, the value of y1 is 0.1-0.2;

[0020] V.Al x3 Ga 1-x3 In the waveguide layer on As, the value of x3 ranges from 0.1 to 0.3;

[0021] VI.Al x3 Ga 1-x3 As z2 P 1-z2 In the upper waveguide layer, x3 takes values ​​of 0.1-0.3, and z2 takes values ​​of 0.95-0.99;

[0022] VII.Al x4 Ga 1-x4 In the As P-restricted layer, 0.7 ≤ x4 ≤ 0.9.

[0023] Preferably, the GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure includes one or more of the following conditions:

[0024] I. The thickness of the GaAs buffer layer is 100-300 nm;

[0025] II.Al x1 Ga 1-x1 The thickness of the As N confinement layer is 2-3 μm;

[0026] Ⅲ.In y1 Ga 1-y1 The thickness of the As quantum well layer is 5-10 nm;

[0027] IV.Al x4 Ga 1-x4 The thickness of the As P confinement layer is 1-3 μm;

[0028] V. The thickness of the GaAs ohmic contact layer is 100-300 nm.

[0029] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure includes the following steps:

[0030] 1. Place the GaAs substrate in the growth chamber of the MOCVD equipment, heat the H2 environment to 740-780℃ 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 and prepare for step 2.

[0031] 2. When the temperature of the reaction chamber drops to 720-750℃, TMGa and AsH3 are introduced to grow a GaAs buffer layer with a thickness of 100-300nm on the GaAs substrate.

[0032] 3. When the reaction chamber temperature drops to 640-680℃, TMAl, TMGa, and AsH3 are introduced to grow Al on the substrate from step 2. x1 Ga 1-x1 As N confinement layer, with a thickness of 2-3 μm;

[0033] 4. Maintain the temperature at 640-680℃. After step 3 is completed, introduce TMAl, TMGa, AsH3, and PH3 to grow Al. x2 Ga 1- x2 As z1 P 1-z1 The lower waveguide layer has a thickness of 10-100 nm;

[0034] 5. Maintain the temperature at 640-680℃. After step 4 is completed, introduce TMAl, TMGa, and AsH3 to grow Al. x2 Ga 1-x2 The As waveguide layer has a thickness of 10-100nm;

[0035] Steps 4 and 5 constitute one cycle of the lower waveguide layer. This cycle is repeated 7 times. The lower waveguide layer consists of 8 cycles of steps 4 and 5, with a total thickness of 800 nm.

[0036] 6. Maintain the temperature at 640-680℃. After step 5 is completed, introduce TMI, TMI, and AsH3 to grow an In layer with a thickness of 5-10 nm. y1 Ga 1-y1 As a quantum well layer;

[0037] 7. Maintain the temperature at 640-680℃. After step 6 is completed, introduce TMAl, TMGa, and AsH3 to grow Al. x3 Ga 1-x3 The waveguide layer on As has a growth thickness of 10-100nm.

[0038] 8. Maintain the temperature at 640-680℃. After step 7 is completed, introduce TMAl, TMGa, AsH3, and PH3 to grow Al. x3 Ga 1- x3 As z2 P 1-z2 The upper waveguide layer has a growth thickness of 10-100 nm.

[0039] Steps 7 and 8 constitute one cycle of the upper waveguide layer. Then, the same cycle is grown three more times. The upper waveguide layer consists of four cycle structures of steps 7 and 8, with a total thickness of 400 nm.

[0040] 9. Maintain the temperature at 640-680℃. After step 8 is completed, introduce TMAl, TMGa, and AsH3 to grow Al. x4 Ga 1-x4 The AsP confinement layer has a thickness of 1-3 μm;

[0041] 10. When the reaction chamber temperature drops to 540-560℃, TMGa and AsH3 are introduced into the Al... x4 Ga 1-x4 GaAs ohmic contact layers with a thickness of 100-300 nm are grown on As P confinement layers.

[0042] Preferably, in step 1, the high-temperature heat treatment temperature is 780℃ and the baking time is 30 minutes.

[0043] Preferably, in step 2, the reaction chamber temperature is 730℃, the growth thickness is 300nm, and the doping concentration is 2E18-5E18 atoms / cm². 3 Further preferably, the doping concentration is 3E18 atoms / cm³. 3 The doping source is Si2H6.

[0044] Preferably, in step 3, the reaction chamber temperature is 680℃, the growth thickness is 2.5µm, 0.3≤x1≤0.5, and the doping concentration is 5E17-2E18 atoms / cm². 3 Further preferably, in step 3, the doping concentration of x1 = 0.4 is 1E18 atoms / cm³. 3 The doping source is Si2H6.

[0045] Preferably, in step 4, the reaction chamber temperature is 680℃, the growth thickness is 50nm, 0.1≤x2≤0.3, 0.95≤z1≤0.99, and the doping concentration is 5E17-2E18 atoms / cm². 3 Further preferably, in step 4, x2 = 0.3, z1 = 0.97, and the doping concentration is 7E17 atoms / cm³. 3 The doping source is Si2H6.

[0046] Preferably, in step 5, the reaction chamber temperature is 680℃, the growth thickness is 50nm, 0.1≤x2≤0.3, and the doping concentration is 5E17-2E18 atoms / cm². 3 Further preferably, in step 5, x2 = 0.2, and the doping concentration is 7E17 atoms / cm³. 3 The doping source is Si2H6.

[0047] Preferably, the reaction chamber temperature in step 6 is 660°C, and the growth thickness is 7 nm. y1 Ga 1-y1 In the As quantum well, y1 takes the value of 0.1-0.2; more preferably, in step 6, In y1 Ga 1-y1 In the As quantum well layer, the value of y1 is 0.15.

[0048] Preferably, the reaction chamber temperature in step 7 is 680°C, the growth thickness is 50 nm, and Al x3 Ga 1-x3 In the As waveguide layer, x3 ranges from 0.1 to 0.3, with a doping concentration of 1E17-5E17 atoms / cm². 3 Further preferred, in step 7, Al x3 Ga 1-x3 In the As waveguide layer, x3 is 0.2, and the doping concentration is 3E17 atoms / cm². 3 The doping source is CBr4.

[0049] Preferably, the reaction chamber temperature in step 8 is 680°C, the growth thickness is 50 nm, and Al x3 Ga 1-x3 As z2 P 1-z2 In the upper waveguide layer, x3 ranges from 0.1 to 0.3, z2 ranges from 0.95 to 0.99, and the doping concentration is 1E17-5E17 atoms / cm². 3 Further preferred, in step 8, Al x3 Ga 1-x3 As z2 P 1-z2 In the upper waveguide layer, x3 is 0.3, z2 is 0.97, and the doping concentration is 3E17 atoms / cm². 3 The doping source is CBr4.

[0050] Preferably, in step 9, the reaction chamber temperature is 680℃, the growth thickness is 1.5µm, 0.7≤x4≤0.9, and the doping concentration is 1E18-3E18 atoms / cm². 3 Further preferably, in step 9, x4 = 0.8, and the doping concentration is 2E18 atoms / cm³. 3 The doping source is CBr4.

[0051] Preferably, the reaction chamber temperature in step 10 is 550°C, the growth thickness is 300 nm, and the doping concentration is 9E18-5E19 atoms / cm². 3Further preferably, the doping concentration in step 10 is 5E19 atoms / cm³. 3 The doping source is CBr4.

[0052] This application pertains to the AlGaAs material system. Unlike the AlGaInP material system, which allows for stress reduction through adjusting the In content and thus reducing costs in the die and packaging stages, AlGaAs cannot achieve stress reduction by adjusting the content of Group III elements. Stress reduction in AlGaAs products, especially wafers, can only be achieved by significantly increasing costs in the packaging stage. This invention aims to control the stress of AlGaAs wafers in the epitaxial stage, thereby reducing packaging costs. Since the lattice constant of AlGaAs is greater than that of the GaAs substrate, large compressive strain accumulates within the epitaxial wafer as the growth thickness increases. Because AlGaAs cannot achieve stress reduction by adjusting the Al or Ga content to form a superlattice structure, this invention employs a periodic AlGaAs / AlGaAsP structure to release stress. The addition of P generates tensile strain in AlGaAsP, which counteracts the compressive strain in AlGaAs, achieving stress balance. Traditional periodic structures in AlGaInP material systems are formed by adjusting the content of group III sources. This invention introduces a new group V source, P element, without changing the group III source. By adjusting the content of the group V source, a special periodic structure is formed, introducing tensile strain to balance the compressive strain brought by AlGaAs material, thus solving the problem of strain release in AlGaAs material systems.

[0053] The beneficial effects of this invention are as follows:

[0054] In this application, Si2H6 is selected for doping on the N side and CBr4 is selected for doping on the P side. The role of doping on the N side is to provide electrons, and the potential difference achieved by the change of the doping gradient is conducive to the migration of electrons into the quantum well. The role of doping on the P side is to provide holes, and the potential difference achieved by the change of the doping gradient is conducive to the migration of holes into the quantum well, ultimately realizing the recombination of holes and electrons in the quantum well. Attached Figure Description

[0055] Figure 1 This is a structural diagram of an epitaxial wafer with controllable mechanical stress. Detailed Implementation

[0056] The present invention will be further described below with reference to the embodiments and accompanying drawings, but is not limited thereto.

[0057] Example 1:

[0058] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure includes the following steps:

[0059] 1. Place the GaAs substrate in the growth chamber of the MOCVD equipment, heat the H2 environment to 780℃ and bake for 30 minutes, then introduce AsH3 to perform high-temperature heat treatment on the GaAs substrate to remove water and oxygen on the substrate surface and prepare for step 2.

[0060] 2. When the reaction chamber temperature drops to 730℃, TMGa and AsH3 are introduced to grow a GaAs buffer layer with a thickness of 300nm on the GaAs substrate; the doping concentration is 3E18 atoms / cm². 3 The doping source is Si2H6.

[0061] 3. When the reaction chamber temperature drops to 680℃, TMAl, TMGa, and AsH3 are introduced to grow Al on the substrate from step 2. x1 Ga 1- x1 An AsN confinement layer with a thickness of 2.5 μm; x1 = 0.4, with a doping concentration of 1E¹⁸ atoms / cm². 3 The doping source is Si2H6;

[0062] 4. Maintain the temperature at 680℃. After step 3 is completed, introduce TMAl, TMGa, AsH3, and PH3 to grow Al. x2 Ga 1- x2 As z1 P 1-z1 The lower waveguide layer has a thickness of 50 nm; x2 = 0.3, z1 = 0.97, and a doping concentration of 7E17 atoms / cm². 3 The doping source is Si2H6;

[0063] 5. Maintain the temperature at 680℃. After step 4 is completed, introduce TMAl, TMGa, and AsH3 to grow Al. x2 Ga 1-x2 The underlying waveguide layer is made of As with a thickness of 50 nm; x2 = 0.2, and the doping concentration is 7E17 atoms / cm². 3 The doping source is Si2H6;

[0064] Steps 4 and 5 constitute one cycle of the lower waveguide layer. This cycle is repeated 7 times. The lower waveguide layer consists of 8 cycles of steps 4 and 5, with a total thickness of 800 nm.

[0065] 6. Maintain the temperature at 680℃. After step 5 is completed, introduce TMIn, TMGa, and AsH3 to grow an In layer with a thickness of 7 nm. y1 Ga1-y1 As a quantum well layer; the value of y1 is 0.15;

[0066] 7. Maintain the temperature at 680℃. After step 6 is completed, introduce TMAl, TMGa, and AsH3 to grow Al. x3 Ga 1-x3 An As waveguide layer is grown to a thickness of 50 nm; x3 is 0.2, and the doping concentration is 3E17 atoms / cm². 3 The doping source is CBr4;

[0067] 8. Maintain the temperature at 680℃. After step 7 is completed, introduce TMAl, TMGa, AsH3, and PH3 to grow Al. x3 Ga 1- x3 As z2 P 1-z2 The upper waveguide layer has a growth thickness of 50 nm; x3 is 0.3, z2 is 0.97, and the doping concentration is 3E17 atoms / cm². 3 The doping source is CBr4;

[0068] Steps 7 and 8 constitute one cycle of the upper waveguide layer. Then, the same cycle is grown three more times. The upper waveguide layer consists of four cycle structures of steps 7 and 8, with a total thickness of 400 nm.

[0069] 9. Maintain the temperature at 680℃. After step 8 is completed, introduce TMAl, TMGa, and AsH3 to grow Al. x4 Ga 1-x4 As-P confinement layer, thickness 1.5 μm; x4 = 0.8, doping concentration 2E18 atoms / cm² 3 The doping source is CBr4;

[0070] 10. When the reaction chamber temperature drops to 550℃, TMGa and AsH3 are introduced into Al... x4 Ga 1-x4 A GaAs ohmic contact layer with a thickness of 300 nm is grown on an As P confinement layer; the doping concentration is 5E19 atoms / cm². 3 The doping source is CBr4.

[0071] The GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure, prepared using the method described in Example 1, comprises, from bottom to top, a GaAs substrate, a GaAs buffer layer, and an Al... x1 Ga 1-x1 As N-confining layer, lower waveguide layer, In y1 Ga 1-y1 As quantum well layer, upper waveguide layer, Al x4 Ga1-x4 As P confinement layer, GaAs ohmic contact layer; lower waveguide layer includes periodically grown Al x2 Ga 1-x2 As z1 P 1-z1 Lower waveguide layer, Al x2 Ga 1-x2 The lower waveguide layer is composed of periodically grown Al; the upper waveguide layer consists of a lower waveguide layer and an upper waveguide layer. x3 Ga 1-x3 As upper waveguide layer, Al x3 Ga 1-x3 As z2 P 1-z2 Upper waveguide layer.

[0072] Example 2:

[0073] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure, the steps of which are as described in Example 1, except that in steps 4 and 5, Al... x2 Ga 1-x2 As z1 P 1-z1 The thickness of the lower waveguide layer is 10 nm, Al x2 Ga 1- x2 The thickness of the lower waveguide layer is 90 nm; after 8 cycles of growth, the total thickness of the lower waveguide layer is 800 nm.

[0074] Example 3:

[0075] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure, the steps of which are as described in Example 1, except that in steps 4 and 5, Al... x2 Ga 1-x2 As z1 P 1-z1 The thickness of the lower waveguide layer is 90 nm, Al x2 Ga 1- x2 The thickness of the lower waveguide layer is 10 nm; after 8 cycles of growth, the total thickness of the lower waveguide layer is 800 nm.

[0076] Example 4:

[0077] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure, the steps of which are as described in Example 1, except that in steps 7 and 8, Al... x3 Ga 1-x3 The thickness of the waveguide layer on As is 10 nm, Al x3 Ga 1- x3 As z2P 1-z2 The thickness of the upper waveguide layer is 90 nm; after four growth cycles, the total thickness of the upper waveguide layer is 400 nm.

[0078] Example 5:

[0079] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure, the steps of which are as described in Example 1, except that in steps 7 and 8, Al... x3 Ga 1-x3 The thickness of the waveguide layer on As is 90 nm, Al x3 Ga 1- x3 As z2 P 1-z2 The thickness of the upper waveguide layer is 10 nm; after four growth cycles, the total thickness of the upper waveguide layer is 400 nm.

[0080] Example 6:

[0081] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure is provided, the steps of which are as described in Example 1, except that in steps 4 and 5, x2 is 0.1 and z1 is 0.95.

[0082] Example 7:

[0083] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure is provided, the steps of which are as described in Example 1, except that in steps 4 and 5, x2 is 0.3 and z1 is 0.99.

[0084] Example 8:

[0085] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure is provided, the steps of which are as described in Example 1, except that in steps 7 and 8, x3 is 0.1 and z2 is 0.95.

[0086] Example 9:

[0087] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure is provided, the steps of which are as described in Example 1, except that in steps 7 and 8, x3 is 0.3 and z2 is 0.99.

[0088] Example 10:

[0089] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure, the steps of which are as described in Example 1, except that Al... x1 Ga 1-x1In the N-bound layer, x1 takes the value of 0.3. y1 Ga 1-y1 In the As quantum well layer, y1 takes the value of 0.1, Al x4 Ga 1-x4 In the As P confinement layer, the value of x4 is 0.7.

[0090] Example 11:

[0091] A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure, the steps of which are as described in Example 1, except that Al... x1 Ga 1-x1 In the N-bound layer, x1 takes the value of 0.5. y1 Ga 1-y1 In the As quantum well layer, y1 takes the value of 0.2, Al x4 Ga 1-x4 In the As P confinement layer, the value of x4 is 0.9.

[0092] Comparative Example 1:

[0093] Lower waveguide layer Al x2 Ga 1-x2 As uses Al 0.3 Ga 0.7 As, with a thickness of 800 nm, and an upper waveguide layer Al x3 Ga 1-x3 As uses Al 0.3 Ga 0.7 As, with a thickness of 400nm, and other parameters remaining unchanged (the purpose is to compare the difference between traditional bulk material waveguides and the periodic structure of AlGaAsP / AlGaAs used as the waveguide layer in this patent).

[0094] Comparative Example 2: Lower waveguide layer Al x2 Ga 1-x2 As z1 P 1-z1 / Al x2 Ga 1-x2 As uses Al 0.3 Ga 0.7 As 0.97 P 0.03 / Al 0.3 Ga 0.7 An As periodic structure with 8 periods and a total thickness of 800 nm, top waveguide layer Al. x3 Ga 1-x3 As / Al x3 Ga 1-x3 As z2 P 1-z2 Using AI 0.3 Ga0.7 As / Al 0.3 Ga 0.7 As 0.97 P 0.03 The structure has 8 periods and a total thickness of 800nm ​​(the effect of thickness is compared on the basis of the same waveguide layer structure).

[0095] Comparative Example 3: Lower Waveguide Layer Al x2 Ga 1-x2 As z1 P 1-z1 / Al x2 Ga 1-x2 As uses Al 0.3 Ga 0.7 As 0.97 P 0.03 / Al 0.3 Ga 0.7 An As periodic structure with four periods and a total thickness of 400 nm, top waveguide layer Al. x3 Ga 1-x3 As / Al x3 Ga 1-x3 As z2 P 1-z2 Using AI 0.3 Ga 0.7 As / Al 0.3 Ga 0.7 As 0.97 P 0.03 The structure has four periods and a total thickness of 400 nm.

[0096] Comparative Example 4: The lower waveguide layer is composed of 50nm thick Al 0.3 Ga 0.7 As and Al with a thickness of 50nm 0.25 Ga 0.75 As consists of a single-cycle superlattice structure with a total of 8 cycles and a total thickness of 800 nm. The upper waveguide layer is composed of 50 nm thick Al. 0.25 Ga 0.75 As and Al with a thickness of 50nm 0.3 Ga 0.7 As consists of a superlattice structure with one cycle, a total of 4 cycles, and a total thickness of 400 nm.

[0097] The 62-LED bar chip of Embodiment 1 and the four comparative examples of the present invention were fabricated using the same die-cutting process and packaged with In solder. The samples were then subjected to pulse testing at 600A and 200us.

[0098]

[0099] Test results show that the patented application has the advantages of high output power, low threshold current, and small slow axis divergence angle. By comparing the results with those of Comparative Examples 1-4, the waveguide adopting the periodic structure of AlGaAs / AlGaAsP has the effect of improving photoelectric parameters. Under the same die and packaging process conditions, the smaller the internal stress of the epitaxial wafer, the smaller the slow axis divergence angle at 86% power. By comparing the slow axis divergence angle at 86% power, it can be clearly seen that the slow axis divergence angle of this patent is the smallest, which verifies the stress relief effect of this patent.

Claims

1. A GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure, characterized in that, From bottom to top, it includes a GaAs substrate, a GaAs buffer layer, and an Al layer. x1 Ga 1-x1 As N-confining layer, lower waveguide layer, In y1 Ga 1-y1 As quantum well layer, upper waveguide layer, Al x4 Ga 1-x4 As P confinement layer, GaAs ohmic contact layer; The lower waveguide layer includes periodically grown Al x2 Ga 1-x2 As z1 P 1-z1 Lower waveguide layer, Al x2 Ga 1-x2 As under-waveguide layer; one layer of Al x2 Ga 1-x2 As z1 P 1-z1 Lower waveguide layer and one layer of Al x2 Ga 1-x2 As the lower waveguide layer has one period, the lower waveguide layer has a total of 8 periods; The upper waveguide layer includes periodically grown Al x3 Ga 1-x3 As upper waveguide layer, Al x3 Ga 1-x3 As z2 P 1-z2 Upper waveguide layer; one layer of Al x3 Ga 1-x3 As upper waveguide layer and one layer of Al x3 Ga 1-x3 As z2 P 1-z2 The upper waveguide layer has one cycle, and the upper waveguide layer has a total of 4 cycles; Al x1 Ga 1-x1 In the As N-confined layer, 0.3 ≤ x1 ≤ 0.5; Al x2 Ga 1-x2 As z1 P 1-z1 In the lower waveguide layer, 0.1≤x2≤0.3, 0.95≤z1≤0.99; Al x2 Ga 1-x2 In the lower waveguide layer As, 0.1 ≤ x2 ≤ 0.3; In y1 Ga 1-y1 In the As quantum well layer, y1 takes values ​​between 0.1 and 0.2; Al x3 Ga 1-x3 In the waveguide layer on As, x3 takes values ​​between 0.1 and 0.3; Al x3 Ga 1-x3 As z2 P 1-z2 In the upper waveguide layer, x3 takes values ​​of 0.1-0.3, and z2 takes values ​​of 0.95-0.99; Al x4 Ga 1-x4 In the As P-restricted layer, 0.7 ≤ x4 ≤ 0.

9.

2. The GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure according to claim 1, characterized in that, Al x2 Ga 1-x2 As z1 P 1-z1 The thickness of the lower waveguide layer is 10-100 nm, Al x2 Ga 1-x2 The thickness of the As waveguide layer is 10-100 nm; after 8 cycles of growth, the total thickness of the lower waveguide layer is 800 nm.

3. The GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure according to claim 1, characterized in that, Al x3 Ga 1-x3 The thickness of the waveguide layer on As is 10-100 nm, Al x3 Ga 1-x3 As z2 P 1-z2 The thickness of the upper waveguide layer is 10-100 nm; after four growth cycles, the total thickness of the upper waveguide layer is 400 nm.

4. The GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure according to claim 1, characterized in that, GaAs-based high-power laser epitaxial wafers with mechanically stress-controllable structures, comprising one or more of the following conditions: I. The thickness of the GaAs buffer layer is 100-300 nm; II.Al x1 Ga 1-x1 The thickness of the As N confinement layer is 2-3 μm; III. In y1 Ga 1-y1 The thickness of the As quantum well layer is 5-10 nm; IV. Al x4 Ga 1-x4 The thickness of the As P confinement layer is 1-3 μm; V. The thickness of the GaAs ohmic contact layer is 100-300 nm.

5. A method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure, comprising the following steps: 1) Place the GaAs substrate in the growth chamber of the MOCVD equipment, heat the H2 environment to 740-780℃ and bake for 20-40 minutes, then introduce AsH3 to heat-treat the GaAs substrate to remove water and oxygen from the substrate surface, and prepare for step 2). 2) When the temperature of the reaction chamber drops to 720-750℃, TMGa and AsH3 are introduced to grow a GaAs buffer layer with a thickness of 100-300nm on the GaAs substrate. 3). When the reaction chamber temperature drops to 640-680℃, TMAl, TMGa, and AsH3 are introduced to grow Al on the substrate from step 2). x1 Ga 1- x1 As N confinement layer, with a thickness of 2-3 μm; 4) Maintain the temperature at 640-680℃. After step 3) is completed, introduce TMAl, TMGa, AsH3 and PH3 to grow Al. x2 Ga 1- x2 As z1 P 1-z1 The lower waveguide layer has a thickness of 10-100 nm; 5) Maintain the temperature at 640-680℃. After step 4) is completed, introduce TMAl, TMGa, and AsH3 to grow Al. x2 Ga 1-x2 The As waveguide layer has a thickness of 10-100nm; Steps 4) and 5) constitute one cycle of the lower waveguide layer. This cycle is repeated 7 times. The lower waveguide layer consists of 8 cycles of steps 4) and 5), with a total thickness of 800 nm. 6) Maintain the temperature at 640-680℃. After step 5) is completed, introduce TMI, TMGa, and AsH3 to grow an In layer with a thickness of 5-10 nm. y1 Ga 1-y1 As a quantum well layer; 7) Maintain the temperature at 640-680℃. After step 6) is completed, introduce TMAl, TMGa, and AsH3 to grow Al. x3 Ga 1-x3 The waveguide layer on As has a growth thickness of 10-100 nm. 8) Maintain the temperature at 640-680℃. After step 7) is completed, introduce TMAl, TMGa, AsH3 and PH3 to grow Al. x3 Ga 1- x3 As z2 P 1-z2 The upper waveguide layer has a growth thickness of 10-100 nm. Steps 7) and 8) constitute one cycle of the upper waveguide layer. Then, the same cycle is grown three more times. The upper waveguide layer consists of four cycle structures of steps 7) and 8), with a total thickness of 400 nm. 9) Maintain the temperature at 640-680℃. After step 8) is completed, introduce TMAl, TMGa, and AsH3 to grow Al. x4 Ga 1-x4 As P confinement layer, with a thickness of 1-3 μm; 10). When the reaction chamber temperature drops to 540-560℃, TMGa and AsH3 are introduced into Al. x4 Ga 1-x4 GaAs ohmic contact layers with a thickness of 100-300 nm are grown on As P confinement layers.

6. The method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure according to claim 5, characterized in that, The preparation steps include one or more of the following conditions: I. In step 1), the heat treatment temperature is 780℃ and the baking time is 30 minutes; II. In step 2), the reaction chamber temperature is 730℃, the growth thickness is 300nm, and the doping concentration is 2E18-5E18 atoms / cm². 3 ; III. In step 3), the reaction chamber temperature is 680℃, the growth thickness is 2.5µm, 0.3≤x1≤0.5, and the doping concentration is 5E17-2E18 atoms / cm². 3 ; IV. The reaction chamber temperature in step 6) is 660℃, and the growth thickness is 7nm. y1 Ga 1-y1 In the As quantum well, y1 takes values ​​between 0.1 and 0.

2. V. In step 9), the reaction chamber temperature is 680℃, the growth thickness is 1.5µm, 0.7≤x4≤0.9, and the doping concentration is 1E18-3E18 atoms / cm². 3 ; VI. In step 10), the reaction chamber temperature is 550℃, the growth thickness is 300nm, and the doping concentration is 9E18-5E19 atoms / cm². 3 .

7. The method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure according to claim 6, characterized in that, In step 2), the doping concentration is 3E18 atoms / cm³. 3 The doping source is Si2H6; in step 3), x1 = 0.4, and the doping concentration is 1E18 atoms / cm³. 3 The doping source is Si2H6; in step 6), In y1 Ga 1-y1 In the As quantum well layer, y1 takes the value of 0.15; in step 9), x4 = 0.8, and the doping concentration is 2E18 atoms / cm³. 3 The doping source is CBr4; the doping concentration in step 10) is 5E19 atoms / cm³. 3 The doping source is CBr4.

8. The method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure according to claim 5, characterized in that, The reaction chamber temperature in step 4) is 680℃, the growth thickness is 50nm, 0.1≤x2≤0.3, 0.95≤z1≤0.99, and the doping concentration is 5E17-2E18 atoms / cm². 3 .

9. The method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure according to claim 8, characterized in that, In step 4), x2 = 0.3, z1 = 0.97, and the doping concentration is 7E17 atoms / cm³. 3 The doping source is Si2H6.

10. The method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure according to claim 5, characterized in that, The reaction chamber temperature in step 5) is 680℃, the growth thickness is 50nm, 0.1≤x2≤0.3, and the doping concentration is 5E17-2E18 atoms / cm². 3 .

11. The method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure according to claim 10, characterized in that, In step 5), x2 = 0.2, and the doping concentration is 7E17 atoms / cm³. 3 The doping source is Si2H6.

12. The method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure according to claim 5, characterized in that, The reaction chamber temperature in step 7) is 680℃, the growth thickness is 50nm, and Al x3 Ga 1-x3 In the As waveguide layer, x3 ranges from 0.1 to 0.3, with a doping concentration of 1E17-5E17 atoms / cm². 3 ; The reaction chamber temperature in step 8) is 680℃, the growth thickness is 50nm, and Al x3 Ga 1-x3 As z2 P 1-z2 In the upper waveguide layer, x3 ranges from 0.1 to 0.3, z2 ranges from 0.95 to 0.99, and the doping concentration is 1E17-5E17 atoms / cm². 3 .

13. The method for fabricating a GaAs-based high-power laser epitaxial wafer with a mechanically stress-controllable structure according to claim 12, characterized in that, Step 7) Al x3 Ga 1-x3 In the As waveguide layer, x3 is 0.2, and the doping concentration is 3E17 atoms / cm². 3 The doping source is CBr4; in step 8), Al x3 Ga 1-x3 As z2 P 1-z2 In the upper waveguide layer, x3 is 0.3, z2 is 0.97, and the doping concentration is 3E17 atoms / cm². 3 The doping source is CBr4.

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