AlGaInP-based transverse mode semiconductor laser and preparation method thereof

Abstract

The application relates to an AlGaInP-based transverse mode semiconductor laser and a preparation method thereof. The laser comprises, from bottom to top, a GaAs substrate, a GaAs buffer layer, a Ga 0.5 In 0.5 P lower transition layer, an Al 0.5 In 0.5 P lower confinement layer, an (Al 1‑x1 Ga x1 ) y1 In 1‑y1 P graded lower waveguide layer, a Ga 1‑x2 In x2 P first quantum well, an (Al 1‑x3 Ga x3 ) y2 In 1‑y2 P barrier layer, a Ga 1‑x4 In x4 P second quantum well, an (Al 1‑ x5 Ga x5 ) y3 In 1‑y3 P graded upper waveguide layer, an Al 0.5 In 0.5 P first upper confinement layer, an Al 0.5 In 0.5 P second upper confinement layer, a Ga 0.5 In 0.5 P upper transition layer and a GaAs cap layer. The AlGaInP-based transverse mode semiconductor laser provided by the application increases the thickness of the Al 0.5 In 0.5 P first upper confinement layer, reduces the doping concentration of the Al 0.5 In 0.5 P first upper confinement layer, realizes the reduction of the difference of transverse refractive indexes, stabilizes the basic transverse mode and improves the kink power, and avoids the influence of current diffusion on electrical parameters after the thickness of the Al 0.5 In 0.5 P first upper confinement layer is increased.

Description

TECHNICAL FIELD

[0001] The application relates to an AlGaInP-based transverse mode semiconductor laser and a preparation method thereof, and belongs to the optical electronic technical field. BACKGROUND

[0002] Compared with quartz optical fibers, plastic optical fibers are low in cost, flexible, large in radius of central core line, easy to splice and operate, and are widely used in short-distance optical fiber communication. The plastic optical fibers taking PMMA as the core have a minimum loss window at a wavelength of about 650 nm, so that AlGaInP-based 650 nm semiconductor lasers have wide application prospects in the field of optical fiber communication.

[0003] Single-mode semiconductor lasers are good in stability, coherence and beam quality, are favorable for improving optical fiber coupling efficiency, and are most suitable for providing light sources for optical fiber transmission. Ridge-shaped semiconductor lasers are simple in process, the effective refractive index of non-ridge region material is changed by changing the ridge shape, the restriction on lateral high-order modes is good, the fundamental mode is more concentrated in the center position of the active region, and the fundamental transverse mode operation is favorable, but the ridge shape, size and etching depth affect the kink effect and easily cause high-order mode lasing.

[0004] The document IEEE Journal of quantum electronics, Vol 41 (6), 2005, Pg 828-832 indicates that the ridge width and the thickness of the residual confinement layer affect the fundamental mode output power, the small ridge width is favorable for improving the fundamental transverse mode output power, the greater the thickness of the residual confinement layer, the smaller the effective refractive index difference, and the same is favorable for improving the fundamental transverse mode output power, and the ridge width and the thickness of the residual confinement layer cooperate to improve the fundamental transverse mode output power. However, the AlGaInP material usually needs to adopt an off-angle substrate to suppress the formation of an ordered structure, and the ridge formed after wet etching of the off-angle substrate is asymmetric, which often affects the output mode of the laser.

[0005] The document Japanese Journal of Applied Physics, Vol 43 (4), 2004, Pg 1991-1995 indicates that dry etching is adopted to replace the traditional wet etching, the ridge is relatively steeper, the asymmetric ridge after wet etching caused by the off-angle of the substrate can be avoided, the series resistance is smaller, the generated heat is reduced, and the photoelectric conversion efficiency is improved. However, the influence of the ridge width on the fundamental transverse mode is not involved.

[0006] Chinese patent document CN101359806A discloses a semiconductor laser device and its manufacturing method. By narrowing the ridge width and gradually changing the ridge width, the effective refractive index difference between the ridge region and the non-ridge region is adjusted, the fundamental transverse mode is stabilized, and the thermal saturation efficiency is improved. However, the key lies in the design of the ridge with gradually changing width. The influence of the remaining confinement layer thickness on the refractive index difference is not analyzed, which makes the fundamental transverse mode unstable and results in low kink power. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an AlGaInP-based transverse mode semiconductor laser and its fabrication method.

[0008] The technical solution of the present invention is as follows:

[0009] An AlGaInP-based transverse mode semiconductor laser comprises, from bottom to top: a GaAs substrate, a GaAs buffer layer, and a GaAs layer. 0.5 In 0.5 P-transition layer, Al 0.5 In 0.5 P-lower confinement layer, (Al) 1-x1 Ga x1 ) y1 In 1-y1 P-gradient waveguide layer, Ga 1-x2 In x2 P first quantum well, (Al) 1-x3 Ga x3 ) y2 In 1-y2 P barrier layer, Ga 1-x4 In x4 P second quantum well, (Al) 1-x5 Ga x5 ) y3 In 1-y3 P-gradient upper waveguide layer, Al 0.5 In 0.5 P first upper confinement layer, Al 0.5 In 0.5 P second upper confinement layer, Ga 0.5 In 0.5 P-transition layer and GaAs cap layer.

[0010] According to a preferred embodiment of the present invention, the substrate is a GaAs substrate.

[0011] According to a preferred embodiment of the present invention, the GaAs buffer layer is a GaAs material doped with silicon atoms, the doping source is Si2H6, the thickness is 0.1-0.3 μm, and the doping concentration is 2×10⁻⁶. 18 -5×10 18 atoms / cm 3Preferably, the buffer layer has a thickness of 0.2 μm and a silicon atom doping concentration of 2 × 10⁻⁶. 18 atoms / cm 3 .

[0012] According to a preferred embodiment of the present invention, the Ga 0.5 In 0.5 The lower transition layer under P is doped with silicon atoms, with Si2H6 as the dopant source, a thickness of 0.1-0.3 μm, and a doping concentration of 2 × 10⁻⁶. 18 -5×10 18 atoms / cm 3 Preferably, the Ga 0.5 In 0.5 The thickness of the transition layer under P is 0.2 μm; the doping concentration is 4 × 10⁻⁶. 18 atoms / cm 3 .

[0013] According to a preferred embodiment of the present invention, the Al 0.5 In 0.5 The lower confinement layer of P is of type n Al. 0.5 In 0.5 The lower confinement layer (P-layer) is doped with silicon atoms, with Si₂H₆ as the dopant source, a thickness of 0.7-1.5 μm, and a doping concentration of 7 × 10⁻⁶. 17 -2×10 18 atoms / cm 3 Preferably, the Al 0.5 In 0.5 The thickness of the P-confinement layer is 1.2 μm; the doping concentration is 1 × 10⁻⁶. 18 atoms / cm 3 .

[0014] According to a preferred embodiment of the present invention, the (Al) 1-x1 Ga x1 ) y1 In 1-y1 The thickness of the waveguide layer with P-gradient gradient is 0.05-0.15 μm, unintentionally doped, with x1 gradient from 0.05 to 0.6, and 0.4 ≤ y1 ≤ 0.6. Preferably, the (Al) 1-x1 Ga x1 ) y1 In 1-y1 The thickness of the waveguide layer is 0.07 μm under the P-gradient, x1 is gradually changed from 0.05 to 0.5, and y1 = 0.5.

[0015] According to a preferred embodiment of the present invention, the Ga 1-x2 In x2 The thickness of the first quantum well (P) is 4-7 nm, unintentionally doped, with a strength of 0.3 ≤ x² ≤ 0.5, and subjected to compressive strain. Preferably, the Ga... 1-x2 Inx2 The thickness of the first quantum well is 6 nm, and x2 = 0.4.

[0016] According to a preferred embodiment of the present invention, the (Al) 1-x3 Ga x3 ) y2 In 1-y2 The P-barrier layer has a thickness of 5-15 nm, is unintentionally doped, has a tensile strain of 0.3 ≤ x³ ≤ 0.6 and 0.4 ≤ y² ≤ 0.6. Preferably, the (Al) 1-x3 Ga x3 ) y2 In 1-y2 The thickness of the P barrier layer is 8 nm, x3 = 0.35, y2 = 0.47.

[0017] According to a preferred embodiment of the present invention, the Ga 1-x4 In x4 The thickness of the second quantum well (P) is 4-7 nm, unintentionally doped, 0.3 ≤ x 4 ≤ 0.5, and subjected to compressive strain; preferably, the Ga... 1-x4 In x4 The thickness of the second quantum well is 6 nm, and x4 = 0.4.

[0018] According to a preferred embodiment of the present invention, the (Al) 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the P-graded upper waveguide layer is 0.05-0.15 μm, unintentionally doped, with x5 gradually increasing from 0.05 to 0.6, and 0.4 ≤ y3 ≤ 0.6. Preferably, the (Al) 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the waveguide layer is 0.07 μm, with P gradually decreasing from 0.5 to 0.05, and y3 = 0.5.

[0019] According to a preferred embodiment of the present invention, the Al 0.5 In 0.5 The first upper confinement layer of P is of type Al. 0.5 In 0.5 The first upper confinement layer (P) is doped with magnesium or zinc atoms from Cp₂Mg or DEZn sources, with a thickness of 0.2-0.5 μm and a doping concentration of 2 × 10⁻⁶. 17 -4×10 17 atoms / cm 3 Preferably, the Al 0.5 In 0.5 The thickness of the first upper confinement layer is 0.3 μm, the doping source is Cp₂Mg, and the doping concentration is 3 × 10⁻⁶. 17 atoms / cm3 .

[0020] According to a preferred embodiment of the present invention, the Al 0.5 In 0.5 The second upper confinement layer of P is of type Al. 0.5 In 0.5 The second upper confinement layer (P) is doped with magnesium or zinc atoms from Cp₂Mg or DEZn sources, with a thickness of 0.4-0.8 μm and a doping concentration of 2 × 10⁻⁶. 17 -4×10 17 atoms / cm 3 Preferably, the Al 0.5 In 0.5 The thickness of the second upper confinement layer is 0.5 μm, the doping source is Cp₂Mg, and the doping concentration is 1 × 10⁻⁶. 18 atoms / cm 3 .

[0021] According to a preferred embodiment of the present invention, the Ga 0.5 In 0.5 The transition layer on P is doped with magnesium or zinc atoms, with the doping source being Cp₂Mg or DEZn, and the thickness is 20-40 nm, with a doping concentration of 1.2 × 10⁻⁶. 18 -3×10 18 atoms / cm 3 Preferably, the Ga 0.5 In 0.5 The thickness of the transition layer on P is 24 nm, the doping source is Cp₂Mg, and the doping concentration is 2 × 10⁻⁶. 18 atoms / cm 3 .

[0022] According to a preferred embodiment of the present invention, the GaAs cap layer is a carbon-doped GaAs material with a thickness of 0.1-0.5 μm, the doping source is CBr4, and the doping concentration is 4 × 10⁻⁶. 19 -1×10 20 atoms / cm 3 Preferably, the GaAs cap layer has a thickness of 0.2 μm and a doping concentration of 7 × 10⁻⁶. 19 atoms / cm 3 .

[0023] The fabrication method of the above-mentioned AlGaInP-based transverse mode semiconductor laser includes the following steps:

[0024] The substrate underwent surface heat treatment in the MOCVD growth chamber, followed by epitaxial growth of a GaAs substrate, a GaAs buffer layer, and a GaAs layer from bottom to top. 0.5 In 0.5 P-transition layer, Al 0.5 In0.5 P-lower confinement layer, (Al) 1-x1 Ga x1 ) y1 In 1-y1 P-gradient waveguide layer, Ga 1-x2 In x2 P first quantum well, (Al) 1-x3 Ga x3 ) y2 In 1-y2 P barrier layer, Ga 1-x4 In x4 P second quantum well, (Al) 1-x5 Ga x5 ) y3 In 1-y3 P-gradient upper waveguide layer, Al 0.5 In 0.5 P first upper confinement layer, Al 0.5 In 0.5 P second upper confinement layer, Ga 0.5 In 0.5 After the GaAs cap layer is grown, an ICP dry etching method is used to etch downwards from the GaAs cap layer to the Al layer, followed by a transition layer and a GaAs cap layer. 0.5 In 0.5 The first upper confinement layer is formed to create ridges with a width of 2-4 μm, resulting in an AlGaInP-based transverse mode semiconductor laser.

[0025] According to a preferred embodiment of the present invention, the fabrication method of the AlGaInP-based transverse mode semiconductor laser includes the following steps:

[0026] (1) Place the GaAs substrate in the growth chamber of the MOCVD equipment and bake it at 710-730℃ for 20-40 minutes in H2 environment. Then introduce AsH3 and bake for 20-40 minutes to obtain the heat-treated GaAs substrate. Perform high-temperature heat treatment on the GaAs substrate to remove water and oxygen on the substrate surface and prepare for step (2).

[0027] (2) Reduce the temperature to 670-690℃, with a cooling rate not exceeding 30℃ / min, and introduce TMGa and AsH3 to grow a GaAs buffer layer on the GaAs substrate.

[0028] (3) Keep the temperature at 670-690℃, introduce TMGa, AsH3 and PH3, and stop introducing AsH3 and TMGa during the growth process on the GaAs buffer layer to achieve growth stop. The stop time is 3s to 30s, and the As atoms in the reaction chamber are exhausted.

[0029] (4) Maintain the temperature at 670-690℃ and continue to introduce TMGa, TMIn, and PH3 to grow Ga on the GaAs buffer layer. 0.5 In 0.5 P-level transition layer;

[0030] (5) Raise the temperature to 690-710℃, with a heating rate not exceeding 60℃ / min, and introduce TMAl, TMIn, TMGa and PH3. 0.5 In 0.5 n-type Al grows on the lower transition layer of P. 0.5 In 0.5 P-level confinement layer;

[0031] (6) Lower the temperature to 640-660℃, introduce TMAl, TMIn, TMGa and PH3, and in n-type Al 0.5 In 0.5 Growth on the P-limiting layer (Al) 1-x1 Ga x1 ) y1 In 1-y1 P-gradient lower waveguide layer;

[0032] (7) Maintain the temperature at 640-660℃ and continue to introduce TMI, TMGa, and PH3, in (Al 1-x1 Ga x1 ) y1 In 1-y1 Ga grown on waveguide layer with P-gradient 1-x2 In x2 P-first quantum well;

[0033] (8) Maintain the temperature at 640-660℃, and introduce TMAl, TMIn, TMGa and PH3, in Ga 1-x2 In x2 Growth on the first quantum well (Al) 1-x3 Ga x3 ) y2 In 1-y2 P-barrier layer;

[0034] (9) Maintain the temperature at 640-660℃ and continue to introduce TMI, TMGa, and PH3, in (Al 1-x3 Ga x3 ) y2 In 1-y2 Ga grows on the P barrier layer 1-x4 In x4 P-second quantum well;

[0035] (10) Raise the temperature to 690-710℃ and continue to introduce TMAl, TMIn, TMGa and PH3. 1-x4 Inx4 Growth on the second quantum well (Al) 1-x5 Ga x5 ) y3 In 1-y3 P-gradient upper waveguide layer;

[0036] (11) Maintain the temperature at 690-710℃ and continue to introduce TMAl, TMIn and PH3, in (Al 1-x5 Ga x5 ) y3 In 1-y3 P-type Al grown on a P-graded upper waveguide layer 0.5 In 0.5 P is the first upper constraint layer;

[0037] (12) Maintain the temperature at 690-710℃ and continue to introduce TMAl, TMIn and PH3, in the P-type Al 0.5 In 0.5 P-type Al is grown on the first upper confinement layer. 0.5 In 0.5 P second upper constraint layer;

[0038] (13) Lower the temperature to 670-690℃, introduce TMI, TMGa and AsH3, and in P-type Al 0.5 In 0.5 Ga is grown on the second upper confinement layer of P. 0.5 In 0.5 P-transition layer;

[0039] (14) Lower the temperature to 530-550℃, with a cooling rate not exceeding 40℃ / min, and continue to introduce TMGa and AsH3 into the Ga... 0.5 In 0.5 A GaAs cap layer is grown on the P-transition layer;

[0040] (15) After the GaAs cap layer is grown, ICP dry etching is used to etch downwards from the GaAs cap layer to the P-type Al. 0.5 In 0.5 The first upper confinement layer is formed to create ridges with a width of 2-4 μm, resulting in an AlGaInP-based transverse mode semiconductor laser.

[0041] According to a preferred embodiment of the present invention, in step (1), the temperature is raised to 720°C in an H2 environment and baked for 30 minutes, and then AsH3 is introduced and baked for another 30 minutes.

[0042] According to a preferred embodiment of the present invention, in step (2), the reaction temperature is 680°C.

[0043] According to a preferred embodiment of the present invention, in step (3), the reaction temperature is 680°C.

[0044] According to a preferred embodiment of the present invention, in step (4), the reaction temperature is 680°C.

[0045] According to a preferred embodiment of the present invention, in step (5), the reaction temperature is 700°C.

[0046] According to a preferred embodiment of the present invention, in step (6), the reaction temperature is 650°C.

[0047] According to a preferred embodiment of the present invention, in step (7), the reaction temperature is 650°C.

[0048] According to a preferred embodiment of the present invention, in step (8), the reaction temperature is 650°C.

[0049] According to a preferred embodiment of the present invention, in step (9), the reaction temperature is 650°C.

[0050] According to a preferred embodiment of the present invention, in step (10), the reaction temperature is 700°C.

[0051] According to a preferred embodiment of the present invention, in step (11), the reaction temperature is 700°C.

[0052] According to a preferred embodiment of the present invention, in step (12), the reaction temperature is 700°C.

[0053] According to a preferred embodiment of the present invention, in step (13), the reaction temperature is 680°C.

[0054] According to a preferred embodiment of the present invention, in step (14), the reaction temperature is 550°C.

[0055] The MOCVD equipment and ICP etching equipment used in the method of this invention are all existing technologies.

[0056] In this invention, TMGa, TMIn, TMAl, PH3, AsH3, etc. are all raw materials for MOCVD epitaxial growth, and Si2H6, Cp2Mg, CBr4, DEZn, etc. are all doping sources for epitaxial growth. Except for the cap layer GaAs, the doping source on the upper layer of the quantum well is the same doping source.

[0057] The beneficial effects of this invention are as follows:

[0058] 1. The AlGaInP-based transverse mode semiconductor laser provided by this invention increases the efficiency of Al... 0.5 In 0.5 The thickness of the first upper confinement layer of P reduces the thickness of P-type Al 0.5 In 0.5 The doping concentration of the first upper confinement layer of P reduces the difference in transverse refractive index, stabilizes the base transverse mode, and improves the kink power, while avoiding the increase of Al. 0.5 In 0.5The effect of current diffusion on electrical parameters after the thickness of the first upper confinement layer.

[0059] 2. The AlGaInP-based transverse mode semiconductor laser provided by this invention employs ICP dry etching to etch down to the first upper confinement layer, forming ridges with a width of 2-4 μm. This reduces the ridge width, increases the base transverse mode output power, and simultaneously reduces the threshold current. Furthermore, the use of dry etching effectively avoids the asymmetric spatial hole burning effect caused by ridge asymmetry resulting from wet etching.

[0060] 3. The AlGaInP-based transverse mode semiconductor laser provided by this invention uses Ga... 1-x2 In x2 P first quantum well, (Al) 1- x3 Ga x3 ) y2 In 1-y2 P barrier layer and Ga 1-x4 In x4 The P-type second quantum well forms a superlattice multi-quantum-well barrier structure. Through alternating strained layer growth, the effects of stress are mitigated, material growth quality is improved, internal losses are reduced, and the threshold current is decreased, which helps suppress carrier overflow. Furthermore, strained GaInP quantum wells are used to achieve lasing wavelengths of 615-710 nm. Attached Figure Description

[0061] Figure 1 This is a comparative schematic diagram of the dry etching ridge structure (b) of the laser described in this invention and the conventional wet etching ridge structure (a).

[0062] Figure 2 These are typical PIV curves of the laser (b) described in this invention and a conventional laser (a).

[0063] Where: the horizontal axis represents the operating current 0-40mA, the left side of the vertical axis represents the output power mW, and the right side represents the operating voltage V.

[0064] Figure 3 These are typical spot patterns of the laser (b) described in this invention and a conventional laser (a). Detailed Implementation

[0065] The present invention will be further described below with reference to embodiments and accompanying drawings.

[0066] Unless otherwise specified, all raw materials used in the embodiments are conventional raw materials and are commercially available; all methods used are existing methods unless otherwise specified.

[0067] Example 1

[0068] A method for fabricating an AlGaInP-based transverse-mode semiconductor laser includes the following steps:

[0069] (1) Place the GaAs substrate in the growth chamber of the MOCVD equipment, heat it to 720°C in H2 environment and bake for 30 minutes, then introduce AsH3 and bake for 30 minutes to obtain the heat-treated GaAs substrate; perform high-temperature heat treatment on the GaAs substrate to remove water and oxygen on the substrate surface and prepare for step (2).

[0070] (2) The temperature was lowered to 680℃ at a rate not exceeding 30℃ / min. TMGa and AsH3 were introduced to grow a GaAs buffer layer with a thickness of 0.2μm on the GaAs substrate. The doping source was Si2H6 with a doping concentration of 2×10⁻⁶. 18 atoms / cm 3 ;

[0071] (3) Keep the temperature at 680℃, introduce TMGa, AsH3 and PH3, and stop introducing AsH3 and TMGa during the growth process on the GaAs buffer layer to achieve growth stop. The stop time is 3s to 30s, and the As atoms in the reaction chamber are exhausted.

[0072] (4) Maintain the temperature at 680℃ and continue to introduce TMGa, TMIn, and PH3 to grow a GaAs buffer layer with a thickness of 0.2 μm. 0.5 In 0.5 The lower transition layer is P; the doping source is Si2H6, and the doping concentration is 4×10⁻⁶. 18 atoms / cm 3 ;

[0073] (5) Raise the temperature to 700℃ at a rate not exceeding 60℃ / min, and introduce TMAl, TMIn, TMGa, and PH3. 0.5 In 0.5 n-type Al with a thickness of 1.2 μm is grown on the P-type transition layer. 0.5 In 0.5 The lower confinement layer is P; the doping source is Si2H6, and the doping concentration is 1×10⁻⁶. 18 atoms / cm 3 ;

[0074] (6) Lower the temperature to 650℃, introduce TMAl, TMIn, TMGa and PH3, and in n-type Al 0.5 In 0.5 A 0.07 μm thick (Al) layer is grown on the P-type confinement layer. 1-x1 Ga x1 ) y1 In 1-y1 P-gradient lower waveguide layer; unintentionally doped, x1 gradient from 0.05 to 0.5, y1 = 0.5;

[0075] (7) Maintain the temperature at 650℃ and continue to introduce TMI, TMGa, and PH3, in (Al 1-x1 Ga x1 ) y1 In 1-y1 GaN with a thickness of 6 nm is grown on a waveguide layer with a P-gradient. 1-x2 In x2 P is the first quantum well; unintentionally doped, x2 = 0.4;

[0076] (8) Maintain the temperature at 650℃, and introduce TMAl, TMIn, TMGa and PH3, while Ga... 1-x2 In x2 An 8nm thick (Al) layer is grown on the first quantum well. 1-x3 Ga x3 ) y2 In 1-y2 P-barrier layer; unintentionally doped, x3 = 0.35, y2 = 0.47;

[0077] (9) Maintain the temperature at 650℃ and continue to introduce TMI, TMGa, and PH3, in (Al 1-x3 Ga x3 ) y2 In 1-y2 Ga with a thickness of 6 nm is grown on the P-barrier layer. 1-x4 In x4 P second quantum well; unintentionally doped, x4 = 0.4; steps (7) to (9) form a superlattice multi-quantum-well barrier structure;

[0078] (10) Raise the temperature to 700℃ and continue to introduce TMAl, TMIn, TMGa and PH3, while Ga 1-x4 In x4 A 0.07 μm thick (Al) layer is grown on the second quantum well. 1-x5 Ga x5 ) y3 In 1-y3 P-gradient upper waveguide layer; unintentional doping, x5 graded from 0.5 to 0.05, y3 = 0.5;

[0079] (11) Maintain the temperature at 700℃ and continue to introduce TMAl, TMIn and PH3, in (Al 1-x5 Ga x5 ) y3 In 1-y3 A 0.3 μm thick P-type Al₂O₃ layer is grown on a P-graded upper waveguide. 0.5 In 0.5 The first upper confinement layer is P; the doping source is Cp₂Mg, and the doping concentration is 3 × 10⁻⁶. 17 atoms / cm 3 ;

[0080] (12) Maintain the temperature at 700℃ and continue to introduce TMAl, TMIn and PH3, in the P-type Al 0.5 In 0.5 P-type Al with a thickness of 0.5 μm is grown on the first upper confinement layer. 0.5 In 0.5 The second upper confinement layer is P; the doping source is Cp₂Mg, and the doping concentration is 1×10⁻⁶. 18 atoms / cm 3 ;

[0081] (13) Lower the temperature to 680℃, introduce TMIn, TMGa and AsH3, and in P-type Al 0.5 In 0.5 Ga with a thickness of 24 nm is grown on the second upper confinement layer of P. 0.5 In 0.5 The P-type transition layer is used as the doping source; the doping concentration is 2 × 10⁻⁶. 18 - atom / cm 3 ;

[0082] (14) Lower the temperature to 540℃, with a cooling rate not exceeding 40℃ / min, and continue to introduce TMGa and AsH3, while Ga 0.5 In 0.5 A GaAs cap layer with a thickness of 0.2 μm is grown on the P-transition layer; the doping source is CBr4, and the doping concentration is 7 × 10⁻⁶. 19 atoms / cm 3 ;

[0083] (15) After the GaAs cap layer is grown, ICP dry etching is used to etch downwards from the GaAs cap layer to the P-type Al. 0.5 In 0.5 The first upper confinement layer is formed to create ridges with a width of 3 μm, resulting in an AlGaInP-based transverse mode semiconductor laser.

[0084] Example 2

[0085] A method for fabricating an AlGaInP-based transverse-mode semiconductor laser, as described in Example 1, differs in that:

[0086] Step (2): The thickness of the GaAs buffer layer is 0.1 μm; the doping concentration of silicon atoms is 3 × 10⁻⁶. 18 atoms / cm 3 .

[0087] Step (4): Ga 0.5 In 0.5 The thickness of the transition layer under P is 0.1 μm, and the doping concentration is 2 × 10⁻⁶. 18atoms / cm 3

[0088] Step (5): Al 0.5 In 0.5 The thickness of the P-type confinement layer is 0.7 μm, and the doping concentration is 7 × 10⁻⁶. 17 atoms / cm 3 .

[0089] Step (6): (Al) 1-x1 Ga x1 ) y1 In 1-y1 The thickness of the waveguide layer is 0.05 μm under the P-gradient, x1 is gradually changed from 0.05 to 0.6, and y1 = 0.4.

[0090] Step (7): Ga 1-x2 In x2 The thickness of the first quantum well is 4 nm, and x2 = 0.3.

[0091] Step (8): (Al) 1-x3 Ga x3 ) y2 In 1-y2 The thickness of the P barrier layer is 5 nm, x3 = 0.3, y2 = 0.4.

[0092] Step (9): Ga 1-x4 In x4 The thickness of the second quantum well is 4 nm, x4 = 0.3.

[0093] Step (10): (Al) 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the waveguide layer is 0.05 μm, P is gradually increased from 0.05 to 0.6, and y3 = 0.4.

[0094] Step (11): Al 0.5 In 0.5 The thickness of the first upper confinement layer is 0.2 μm, the doping source is DEZn, and the doping concentration is 2 × 10⁻⁶. 17 atoms / cm 3 .

[0095] Step (12): Al 0.5 In 0.5 The thickness of the second upper confinement layer is 0.4 μm, the doping source is DEZn, and the doping concentration is 2 × 10⁻⁶. 17 atoms / cm 3 .

[0096] Step (13): Ga 0.5 In0.5 The thickness of the transition layer on P is 20 nm, and the doping source is DEZn, 1.2 × 10⁻⁶. 18 atoms / cm 3 .

[0097] Step (14): The thickness of the GaAs cap layer is 0.1 μm, 4 × 10⁻⁶. 19 atoms / cm 3 .

[0098] Step (15): The ridge width is 2μm.

[0099] The other steps and conditions are the same as in Example 1.

[0100] Example 3

[0101] A method for fabricating an AlGaInP-based transverse-mode semiconductor laser, as described in Example 1, differs in that:

[0102] Step (2): The thickness of the GaAs buffer layer is 0.3 μm; the doping concentration of silicon atoms is 5 × 10⁻⁶. 18 atoms / cm 3 .

[0103] Step (4): Ga 0.5 In 0.5 The thickness of the transition layer under P is 0.3 μm, and the doping concentration is 5 × 10⁻⁶. 18 atoms / cm 3

[0104] Step (5): Al 0.5 In 0.5 The thickness of the P-type confinement layer is 1.5 μm, and the doping concentration is 2 × 10⁻⁶. 18 atoms / cm 3 .

[0105] Step (6): (Al) 1-x1 Ga x1 ) y1 In 1-y1 The thickness of the waveguide layer is 0.15 μm under the P-gradient, x1 is gradually changed from 0.1 to 0.5, and y1 = 0.6.

[0106] Step (7): Ga 1-x2 In x2 The thickness of the first quantum well is 7 nm, and x2 = 0.5.

[0107] Step (8): (Al) 1-x3 Ga x3 ) y2 In 1-y2 The thickness of the P barrier layer is 15 nm, x3 = 0.6, y2 = 0.6.

[0108] Step (9): Ga 1-x4 In x4 The thickness of the second quantum well is 7 nm, x4 = 0.5.

[0109] Step (10): (Al) 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the waveguide layer is 0.15 μm, P is gradually increased from 0.1 to 0.5, and y3 = 0.6.

[0110] Step (11): Al 0.5 In 0.5 The thickness of the first upper confinement layer is 0.5 μm, and the doping concentration is 4 × 10⁻⁶. 17 atoms / cm 3 .

[0111] Step (12): Al 0.5 In 0.5 The thickness of the second upper confinement layer is 0.8 μm, and the doping concentration is 4 × 10⁻⁶. 17 atoms / cm 3 .

[0112] Step (13): Ga 0.5 In 0.5 The thickness of the transition layer on P is 40 nm, 3 × 10⁻⁶ 18 atoms / cm 3 .

[0113] Step (14): The thickness of the GaAs cap layer is 0.5 μm, 1 × 10 20 atoms / cm 3 .

[0114] Step (15): The ridge width is 2μm.

[0115] The other steps and conditions are the same as in Example 1.

[0116] Example 4

[0117] A method for fabricating an AlGaInP-based transverse-mode semiconductor laser, as described in Example 1, differs in that:

[0118] In step (5), the reaction temperature is 690℃.

[0119] In step (6), the reaction temperature is 640℃.

[0120] In step (7), the reaction temperature is 640℃.

[0121] In step (8), the reaction temperature is 640℃.

[0122] In step (9), the reaction temperature is 640℃.

[0123] In step (10), the reaction temperature is 690℃.

[0124] In step (11), the reaction temperature is 690℃.

[0125] In step (12), the reaction temperature is 690℃.

[0126] In step (13), the reaction temperature is 670℃.

[0127] In step (14), the reaction temperature is 530℃.

[0128] The other steps and conditions are the same as in Example 1.

[0129] Comparative Example 1

[0130] A method for fabricating a laser epitaxial wafer, as described in Example 1, except that:

[0131] In the Al 0.5 In 0.5 P first upper confinement layer and Al 0.5 In 0.5 P-type Ga is set between the second upper confinement layer and the P-type Ga. 1- x6 In x6 The P-corrosion termination layer is doped with magnesium atoms from Cp₂Mg, has a thickness of 10 nm, and a doping concentration of 1.5 × 10⁻⁶. 18 atoms / cm 3 x6 = 0.47.

[0132] The final step uses wet etching to etch from the GaAs cap layer down to the P-type Ga. 1-x6 In x6 P-etch termination layer, due to Ga 1-x6 In x6 The corrosion characteristics of the P corrosion termination layer are different, thus achieving the purpose of corrosion termination.

[0133] Schematic diagrams of the ridge structure of Example 1 and Comparative Example 1 are shown below. Figure 1 As shown.

[0134] Depend on Figure 1 As can be seen, in Embodiment 1 of the present invention, the ICP dry etching method has better ridge steepness and smaller ridge width compared with the wet etching method in Comparative Example 1, which is beneficial to improve the base transverse mode output power and improve the kink power.

[0135] Test case

[0136] The PIV characteristic curves of Example 1 and a conventional laser were tested, and the test results are as follows: Figure 2 As shown.

[0137] Depend on Figure 2 It can be seen that conventional lasers have low kink power (as indicated by the dashed arrow), while no kink phenomenon was observed in Embodiment 1 of this invention within 40mA. Therefore, Embodiment 1 of this invention combines dry etching, narrow ridges, and increased Al... 0.5 In 0.5 The thickness of the first upper limiting layer effectively improves the basic transverse mode output power while reducing the adjustment of Al. 0.5 In 0.5 With the doping concentration of the first upper confinement layer and the narrow ridge, the threshold current did not show a significant increase.

[0138] Spot size tests were performed on Example 1 and a conventional laser, and the test results are as follows: Figure 3 As shown.

[0139] Depend on Figure 3 It is known that the beam of a conventional laser is asymmetrical, with one side convex, which is a typical kink-induced change in beam shape. However, the beam of the laser in Embodiment 1 of the present invention is symmetrical and has a better morphology, indicating that kink has not occurred and the output power of the fundamental transverse mode is improved.

Claims

1. An AlGaInP-based transverse-mode semiconductor laser, characterized in that, From bottom to top, it includes: GaAs substrate, GaAs buffer layer, Ga... 0.5 In 0.5 P-transition layer, Al 0.5 In 0.5 P-lower confinement layer, (Al) 1-x1 Ga x1 ) y1 In 1-y1 P-gradient waveguide layer, Ga 1-x2 In x2 P first quantum well, (Al) 1-x3 Ga x3 ) y2 In 1-y2 P barrier layer, Ga 1-x4 In x4 P second quantum well, (Al) 1-x5 Ga x5 ) y3 In 1-y3 P-gradient upper waveguide layer, Al 0.5 In 0.5 P first upper confinement layer, Al 0.5 In 0.5 P second upper confinement layer, Ga 0.5 In 0.5 P-transition layer and GaAs cap layer; Wherein, Ga 1-x2 In x2 The thickness of the first quantum well is 4-7 nm, unintentionally doped, and 0.3 ≤ x2 ≤ 0.5; The (Al) 1-x3 Ga x3 ) y2 In 1-y2 The thickness of the P-barrier layer is 5-15 nm, unintentionally doped, with 0.3≤x3≤0.6 and 0.4≤y2≤0.

6. The Ga 1-x4 In x4 The thickness of the second quantum well is 4-7 nm, unintentionally doped, with 0.3 ≤ x 4 ≤ 0.5; The (Al) 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the waveguide layer with P-gradient is 0.05-0.15 μm, unintentionally doped, x5 is gradually increased from 0.05 to 0.6, and 0.4≤y3≤0.6; The Al 0.5 In 0.5 The first upper confinement layer of P is of type Al. 0.5 In 0.5 The first upper confinement layer (P) is doped with magnesium or zinc atoms from Cp₂Mg or DEZn sources, with a thickness of 0.2-0.5 μm and a doping concentration of 2 × 10⁻⁶. 17 -4×10 17 atoms / cm 3 .

2. The AlGaInP-based transverse mode semiconductor laser as described in claim 1, characterized in that, Includes one or more of the following conditions: i. The substrate is a GaAs substrate; ii. The GaAs buffer layer is a GaAs material doped with silicon atoms, with Si2H6 as the doping source, a thickness of 0.1-0.3 μm, and a doping concentration of 2 × 10⁻⁶. 18 -5×10 18 atoms / cm 3 ; iii. The Ga 0.5 In 0.5 The lower transition layer under P is doped with silicon atoms, with Si2H6 as the dopant source, a thickness of 0.1-0.3 μm, and a doping concentration of 2 × 10⁻⁶. 18 -5×10 18 atoms / cm 3 ; iv. The Al 0.5 In 0.5 The lower confinement layer of P is of type n Al. 0.5 In 0.5 The lower confinement layer (P-layer) is doped with silicon atoms, with Si₂H₆ as the dopant source, a thickness of 0.7-1.5 μm, and a doping concentration of 7 × 10⁻⁶. 17 -2×10 18 atoms / cm 3 ; v, the aforementioned (Al) 1-x1 Ga x1 ) y1 In 1-y1 The thickness of the waveguide layer under the P-gradient is 0.05-0.15μm, unintentionally doped, x1 is gradually changed from 0.05 to 0.6, and 0.4≤y1≤0.

6.

3. The AlGaInP-based transverse mode semiconductor laser as described in claim 2, characterized in that, Includes one or more of the following conditions: i. The thickness of the buffer layer is 0.2 μm, and the silicon atom doping concentration is 2 × 10⁻⁶. 18 atoms / cm 3 ; ii. The Ga 0.5 In 0.5 The thickness of the transition layer under P is 0.2 μm; the doping concentration is 4 × 10⁻⁶. 18 atoms / cm 3 ; iii. The Al 0.5 In 0.5 The thickness of the P-confinement layer is 1.2 μm; the doping concentration is 1 × 10⁻⁶. 18 atoms / cm 3 ; iv. The aforementioned (Al) 1-x1 Ga x1 ) y1 In 1-y1 The thickness of the waveguide layer is 0.07 μm under the P-gradient, x1 is gradually changed from 0.05 to 0.5, and y1=0.

5.

4. The AlGaInP-based transverse mode semiconductor laser as described in claim 1, characterized in that, Includes one or more of the following conditions: i. The Ga 1-x2 In x2 The thickness of the first quantum well is 6 nm, x2 = 0.4; ii. The aforementioned (Al) 1-x3 Ga x3 ) y2 In 1-y2 The thickness of the P barrier layer is 8 nm, x3=0.35, y2=0.47; iii. The Ga 1-x4 In x4 The thickness of the second quantum well is 6 nm, x4 = 0.4; iv. The aforementioned (Al) 1-x5 Ga x5 ) y3 In 1-y3 The thickness of the waveguide layer is 0.07 μm, with x5 gradually changing from 0.5 to 0.05 and y3=0.

5. v. The Al 0.5 In 0.5 The thickness of the first upper confinement layer is 0.3 μm, the doping source is Cp₂Mg, and the doping concentration is 3 × 10⁻⁶. 17 atoms / cm 3 .

5. The AlGaInP-based transverse mode semiconductor laser as described in claim 1, characterized in that, Includes one or more of the following conditions: i. The Al 0.5 In 0.5 The second upper confinement layer of P is of type Al. 0.5 In 0.5 The second upper confinement layer (P) is doped with magnesium or zinc atoms from Cp₂Mg or DEZn sources, with a thickness of 0.4-0.8 μm and a doping concentration of 2 × 10⁻⁶. 17 -4×10 17 atoms / cm 3 ; ii. The Ga 0.5 In 0.5 The transition layer on P is doped with magnesium or zinc atoms, with the doping source being Cp₂Mg or DEZn, and the thickness is 20-40 nm, with a doping concentration of 1.2 × 10⁻⁶. 18 -3×10 18 atoms / cm 3 ; iii. The GaAs cap layer is a carbon-doped GaAs material with a thickness of 0.1-0.5 μm, the doping source is CBr4, and the doping concentration is 4 × 10⁻⁶. 19 -1×10 20 atoms / cm 3 .

6. The AlGaInP-based transverse mode semiconductor laser as described in claim 5, characterized in that, Includes one or more of the following conditions: i. The Al 0.5 In 0.5 The thickness of the second upper confinement layer is 0.5 μm, and the doping concentration is 1 × 10⁻⁶. 18 atoms / cm 3 ; ii. The Ga 0.5 In 0.5 The thickness of the transition layer on P is 24 nm, the doping source is Cp₂Mg, and the doping concentration is 2 × 10⁻⁶. 18 atoms / cm 3 ; iii. The thickness of the GaAs cap layer is 0.2 μm, and the doping concentration is 7 × 10⁻⁶. 19 atoms / cm 3 .

7. A method for fabricating an AlGaInP-based transverse-mode semiconductor laser as described in any one of claims 1-6, comprising the following steps: The substrate underwent surface heat treatment in the MOCVD growth chamber, followed by epitaxial growth of a GaAs substrate, a GaAs buffer layer, and a GaAs layer from bottom to top. 0.5 In 0.5 P-transition layer, Al 0.5 In 0.5 P-lower confinement layer, (Al) 1-x1 Ga x1 ) y1 In 1-y1 P-gradient waveguide layer, Ga 1-x2 In x2 P first quantum well, (Al) 1-x3 Ga x3 ) y2 In 1-y2 P barrier layer, Ga 1-x4 In x4 P second quantum well, (Al) 1-x5 Ga x5 ) y3 In 1-y3 P-gradient upper waveguide layer, Al 0.5 In 0.5 P first upper confinement layer, Al 0.5 In 0.5 P second upper confinement layer, Ga 0.5 In 0.5 After the GaAs cap layer is grown, an ICP dry etching method is used to etch downwards from the GaAs cap layer to the Al layer, followed by a transition layer and a GaAs cap layer. 0.5 In 0.5 The first upper confinement layer is formed to create ridges with a width of 2-4 μm, resulting in an AlGaInP-based transverse mode semiconductor laser.

8. The preparation method according to claim 7, characterized in that, The steps include the following: (1) Place the GaAs substrate in the growth chamber of the MOCVD equipment and bake it at 710-730℃ for 20-40 minutes in H2 environment. Then introduce AsH3 and bake for 20-40 minutes to obtain the heat-treated GaAs substrate. Perform high-temperature heat treatment on the GaAs substrate to remove water and oxygen on the substrate surface and prepare for step (2). (2) Reduce the temperature to 670-690℃, with a cooling rate not exceeding 30℃ / min, and introduce TMGa and AsH3 to grow a GaAs buffer layer on the GaAs substrate; (3) Keep the temperature at 670-690℃, introduce TMGa, AsH3 and PH3, and stop introducing AsH3 and TMGa during the growth process on the GaAs buffer layer to achieve growth cessation. The cessation time is 3s~30s, and the As atoms in the reaction chamber are exhausted. (4) Maintain the temperature at 670-690℃ and continue to introduce TMGa, TMIn and PH3 to grow Ga on the GaAs buffer layer. 0.5 In 0.5 P-level transition layer; (5) Raise the temperature to 690-710℃, with a heating rate not exceeding 60℃ / min, and introduce TMAl, TMIn, TMGa and PH3. 0.5 In 0.5 n-type Al grows on the lower transition layer of P. 0.5 In 0.5 P-level confinement layer; (6) Lower the temperature to 640-660℃, introduce TMAl, TMIn, TMGa and PH3, and in n-type Al 0.5 In 0.5 Growth on the P-limiting layer (Al) 1-x1 Ga x1 ) y1 In 1-y1 P-gradient lower waveguide layer; (7) Maintain the temperature at 640-660℃ and continue to introduce TMI, TMGa and PH3, in (Al 1-x1 Ga x1 ) y1 In 1-y1 Ga grown on waveguide layer with P-gradient 1-x2 In x2 P-first quantum well; (8) Maintain the temperature at 640-660℃, and introduce TMAl, TMIn, TMGa and PH3, in Ga 1-x2 In x2 Growth on the first quantum well (Al) 1-x3 Ga x3 ) y2 In 1-y2 P-barrier layer; (9) Maintain the temperature at 640-660℃ and continue to introduce TMIn, TMGa and PH3, in (Al 1-x3 Ga x3 ) y2 In 1-y2 Ga grows on the P barrier layer 1-x4 In x4 P-second quantum well; (10) Raise the temperature to 690-710℃ and continue to introduce TMAl, TMIn, TMGa and PH3, in Ga 1-x4 In x4 Growth on the second quantum well (Al) 1-x5 Ga x5 ) y3 In 1-y3 P-gradient upper waveguide layer; (11) Maintain the temperature at 690-710℃ and continue to introduce TMAl, TMIn and PH3, in (Al 1-x5 Ga x5 ) y3 In 1-y3 P-type Al grown on a P-graded upper waveguide layer 0.5 In 0.5 P is the first upper constraint layer; (12) Maintain the temperature at 690-710℃ and continue to introduce TMAl, TMIn and PH3, in the P-type Al 0.5 In 0.5 P-type Al is grown on the first upper confinement layer. 0.5 In 0.5 P second upper constraint layer; (13) Lower the temperature to 670-690℃, introduce TMI, TMGa and AsH3, and in P-type Al 0.5 In 0.5 Ga is grown on the second upper confinement layer of P. 0.5 In 0.5 P-transition layer; (14) Reduce the temperature to 530-550℃, with a cooling rate not exceeding 40℃ / min, and continue to introduce TMGa and AsH3, in Ga 0.5 In 0.5 A GaAs cap layer is grown on the P-transition layer; (15) After the GaAs cap layer is grown, ICP dry etching is used to etch downwards from the GaAs cap layer to the P-type Al. 0.5 In 0.5 The first upper confinement layer is formed to create ridges with a width of 2-4 μm, resulting in an AlGaInP-based transverse mode semiconductor laser.

9. The preparation method according to claim 8, characterized in that, Includes one or more of the following conditions: i. In step (1), the temperature is raised to 720°C in H2 environment and baked for 30 minutes, then AsH3 is introduced and baked for another 30 minutes; ii. In step (2), the reaction temperature is 680℃; iii. In step (3), the reaction temperature is 680℃; iv. In step (4), the reaction temperature is 680℃; v. In step (5), the reaction temperature is 700℃; vi. In step (6), the reaction temperature is 650℃; vii. In step (7), the reaction temperature is 650℃; viii. In step (8), the reaction temperature is 650℃; ix. In step (9), the reaction temperature is 650℃; x. In step (10), the reaction temperature is 700℃; xi. In step (11), the reaction temperature is 700℃; xii. In step (12), the reaction temperature is 700℃; xiii. In step (13), the reaction temperature is 680℃; xiv. In step (14), the reaction temperature is 550℃.

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