A red light Vcsel structure and manufacturing method thereof

Abstract

The present invention discloses a red light Vcsel structure and a manufacturing method thereof. The red light Vcsel structure comprises a substrate, a buffer layer, an N-type DBR reflective layer, a resonant cavity layer and a P-type DBR reflective layer; the resonant cavity layer comprises Al 0.5 In 0.5 P lower confinement layer, lower waveguide layer, multi-quantum well layer, upper waveguide layer, electron blocking layer, Al 0.5 In 0.5 The confinement layer on P; the resonant cavity layer satisfies: nL=mλ / 2, where n is the average refractive index of the resonant cavity layer, L is the length of the resonant cavity layer, λ is the resonant wavelength, and m is 3; so that Al 0.5 In 0.5 The thickness of the P lower confinement layer is more than 3 times thicker than that of the conventional short cavity length structure with m=1, which can effectively limit the overflow of carriers; the electron blocking layer is composed of multiple groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1‑x2 Ga x2 ) y2 In 1‑y2 The superlattice structure consists of alternating P layers, where 0.05≤x2≤0.1 and y2>0.52, forming an obvious bandwidth difference, effectively blocking the overflow of carriers, and y2 gradually increases from the lower layer to the upper layer, achieving the electron blocking effect while ensuring the high-quality growth of the epitaxial layer.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor lasers, and in particular relates to a red light Vcsel structure and a manufacturing method thereof. Background Art

[0002] AlGaInP red lasers are widely used in plastic optical fiber transmission, medical cosmetology, laser display and other fields. Among them, red Vcsel (vertical cavity surface emitting laser) has the characteristics of small size, good beam quality, easy integration and low production cost, and thus has attracted more and more attention from the market. For the currently used AlGaInP system red vertical cavity surface emitting lasers, because the lasing wavelength is short and the band gap of the active area material is high, carriers are more likely to overflow from the active area into the confinement layer, thereby reducing the power conversion efficiency and slope efficiency of the device, increasing the threshold current, and the temperature characteristics will deteriorate.

[0003] The existing AlGaInP red vertical cavity surface emitting laser is composed of an N-type DBR reflective layer, an active region of AlGaInP material, an oxide layer, a P-type DBR reflective layer, and a highly doped ohmic contact layer; the active region of the AlGaInP material includes Al 0.5 In 0.5 P confinement layer, (Al 1-x Gax y In 1-y The waveguide layer of P, Ga x In 1-x P and (Al 1-x Ga x ) y In 1-y The resonant cavity of Vcsel is perpendicular to the substrate, and the thickness of the epitaxial layer constitutes the resonant cavity. The length of the resonant cavity needs to satisfy nL=mλ / 2, where n is the average refractive index of the resonant cavity, L is the length of the resonant cavity, λ is the resonant wavelength, and m is a positive integer, m is usually 1, so the length of the resonant cavity is at the nanometer level, which also leads to the Al 0.5 In 0.5 The thickness of the P confinement layer is too thin to effectively limit the overflow of electrons by increasing the thickness of the confinement layer. In addition, the lasing wavelength of the AlGaInP red vertical cavity surface emitting laser is too short, and the band gap of the active area material is too high, so it is easier for carriers to overflow from the active area into the confinement layer. The above reasons lead to the reduction of the power conversion efficiency and slope efficiency of the AlGaInP red vertical cavity surface emitting laser, the increase of the threshold current, and the serious drop of high temperature performance under high temperature conditions. Summary of the invention

[0004] The object of the present invention is to provide a red light Vcsel structure and a manufacturing method thereof. The resonant cavity layer adopts a long cavity length structure and an electron blocking layer is added to form an obvious bandwidth difference, which effectively limits the overflow of carriers.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A red light Vcsel structure comprises a substrate, a buffer layer, an N-type DBR reflective layer, a resonant cavity layer and a P-type DBR reflective layer stacked in sequence from bottom to top;

[0007] The resonant cavity layer includes Al 0.5 In 0.5 P lower confinement layer, lower waveguide layer, multi-quantum well layer, upper waveguide layer, electron blocking layer, Al 0.5 In 0.5 P upper restriction layer;

[0008] The resonant cavity layer satisfies: nL=mλ / 2, where n is the average refractive index of the resonant cavity layer, L is the length of the resonant cavity layer, λ is the resonant wavelength, and m is 3;

[0009] The electron blocking layer is composed of multiple groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The superlattice structure is composed of alternately grown P layers, wherein 0.05≤x2≤0.1, y2>0.52, and y2 gradually increases from the lower layer to the upper layer.

[0010] Optionally, the electron blocking layer is composed of 4 to 6 groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The thickness of a superlattice structure is 20nm. 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The thickness of the P layers was 10 nm each.

[0011] Optionally, the electron blocking layer is composed of 5 groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In1-y2 The superlattice structure consists of an alternating growth of P layers, with the first layer of tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 y2 in the P layer is 0.54, y2 in the second layer is 0.56, y2 in the third layer is 0.58, y2 in the fourth layer is 0.60, and y2 in the fifth layer is 0.62.

[0012] Optionally, the N-type DBR reflective layer and the P-type DBR reflective layer are both formed by alternatingly growing AlGaAs layers with high Al content and AlGaAs layers with low Al content, the Al content of the high Al content AlGaAs layer is in the range of 80%-95%, the Al content of the low Al content AlGaAs layer is in the range of 45%-55%, and a 20nm transition layer is provided between the high Al and low Al content AlGaAs layers; wherein the optical thickness of the high Al content AlGaAs layer plus the transition layer is one quarter of the wavelength of the red light Vcsel emission laser, and the optical thickness of the low Al content AlGaAs layer plus the transition layer is one quarter of the wavelength of the red light Vcsel emission laser.

[0013] Optionally, the number of alternating pairs of the high Al content AlGaAs layer and the low Al content AlGaAs layer of the N-type DBR reflective layer is between 50-60 pairs, and the doping element is the N-type doping element Si; the number of alternating pairs of the high Al content AlGaAs layer and the low Al content AlGaAs layer of the P-type DBR reflective layer is between 25-35 pairs, and the doping element is the P-type doping element C.

[0014] Optionally, the multi-quantum well layer is composed of 4 groups of 7nm thick Ga x In 1-x P layer and 7nm thick (Al 1-x1 Ga x1 ) y1 In 1-y1 The P layers are formed by alternating growth, where 0.4≤x≤0.6, 0.2≤x1≤0.4, and y1=0.5.

[0015] Optionally, the lower waveguide layer and the upper waveguide layer are both (Al 1-x 1Ga x1 ) y1 In 1-y1 P waveguide layer, and the thickness range is 50-100nm, where 0.2≤x1≤0.4, y1=0.5.

[0016] Optionally, the Al 0.5 In 0.5 The thickness of the P lower confinement layer ranges from 150 to 200 nm.0.5 In 0.5 The thickness of the P confinement layer ranges from 50 to 100 nm.

[0017] Optionally, the resonant cavity layer further includes a 0.5 In 0.5 The oxide layer between the P-type limiting layer and the P-type DBR reflective layer is Al 0.98 Ga 0.02 As oxide layer, thickness is 20nm.

[0018] The present invention also provides a method for manufacturing a red light Vcsel structure, comprising:

[0019] growing a buffer layer on the substrate;

[0020] Growing an N-type DBR reflective layer on the buffer layer;

[0021] Growing Al on the reflective layer of N-type DBR 0.5 In 0.5 P lower limiting layer;

[0022] In Al 0.5 In 0.5 A lower waveguide layer is grown on the P lower confinement layer;

[0023] growing a multi-quantum well layer on the lower waveguide layer;

[0024] growing an upper waveguide layer on the multiple quantum well layer;

[0025] An electron blocking layer is grown on the upper waveguide layer. The electron blocking layer is composed of multiple groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The P layers are formed by alternating growth, where 0.05≤x2≤0.1, y2>0.52, and y2 increases gradually from the lower layer to the upper layer;

[0026] Growth of Al on the electron blocking layer 0.5 In 0.5 P upper confinement layer, the Al 0.5 In 0.5 P lower confinement layer, lower waveguide layer, multi-quantum well layer, upper waveguide layer, electron blocking layer and Al 0.5 In 0.5 The upper limiting layer P forms a resonant cavity layer, and the resonant cavity layer satisfies: nL=mλ / 2, wherein n is the average refractive index of the resonant cavity layer, L is the length of the resonant cavity layer, λ is the resonant wavelength, and m is 3;

[0027] In Al0.5 In 0.5 A P-type DBR reflective layer is grown on the P upper confinement layer.

[0028] After adopting the above scheme, the beneficial effects of the present invention are:

[0029] 1. The resonant cavity layer of the present invention satisfies nL=mλ / 2. The larger m is, the larger the length L of the resonant cavity layer is. m of the present invention is 3, which is a long cavity length structure, so that Al 0.5 In 0.5 The thickness of the P lower confinement layer is more than three times thicker than that of the conventional short cavity length structure with m=1, which effectively limits the overflow of carriers, increases the conversion efficiency and slope efficiency, and improves the high temperature performance.

[0030] 2. The present invention also adds an electron blocking layer, which is composed of multiple groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The superlattice structure consists of an alternating growth of P layers, in which y2 increases gradually from the lower layer to the upper layer, and can be slowed down layer by layer (Al 1-x2 Ga x2 ) y2 In 1-y2 The tensile stress of the P layer ensures the high-quality growth of the epitaxial layer while achieving the electron blocking effect. In addition, 0.05≤x2≤0.1, and all y2 are greater than 0.52, so that all tensile stresses (Al 1-x2 Ga x2 ) y2 In 1-y2 The bandwidth of the P layer is better than that of the Al 0.5 In 0.5 The height of the confinement layer on P forms a significant bandwidth difference, which effectively blocks the overflow of carriers, further increases the conversion efficiency and slope efficiency, and improves high-temperature performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the red light Vcsel structure of the present invention;

[0032] Figure 2 A curve diagram showing the bandgap width of each layer of the red light Vcsel structure of the present invention;

[0033] Figure 3 It is a process flow chart of the manufacturing method of the present invention.

[0034] Description of labels:

[0035] 1. Buffer layer; 2. N-type DBR reflective layer; 3. Al 0.5In 0.5 P lower confinement layer; 4, lower waveguide layer; 5, multi-quantum well layer; 6, upper waveguide layer; 7, electron blocking layer; 8, Al 0.5 In 0.5 P upper limiting layer; 9, oxide layer; 10, P-type DBR reflective layer; 11, ohmic contact layer. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] Please refer to Figure 1 The present invention provides a red light Vcsel structure, comprising a substrate, a buffer layer 1, an N-type DBR reflective layer 2, a resonant cavity layer and a P-type DBR reflective layer 10 stacked in sequence from bottom to top.

[0038] The resonant cavity layer includes Al 0.5 In 0.5 P lower confinement layer 3, lower waveguide layer 4, multi-quantum well layer 5, upper waveguide layer 6, electron blocking layer 7, Al 0.5 In 0.5 The confinement layer 8 on P, the resonant cavity layer satisfies: nL=mλ / 2, wherein n is the average refractive index of the resonant cavity layer, L is the length of the resonant cavity layer, λ is the resonant wavelength, and m is 3; the larger m is, the larger the length L of the resonant cavity layer is. In the present invention, m is selected as 3, which is a long cavity length structure, specifically 3 times the cavity length is adopted, so that Al 0.5 In 0.5 The thickness of the P lower confinement layer 3 is more than three times thicker than that of the conventional short cavity length structure with m being 1, and the thickness ranges from 150 to 200 nm, which can effectively limit the overflow of carriers, increase the conversion efficiency, slope efficiency, and improve the high temperature performance.

[0039] It should be noted that the resonant cavity layer also includes a small part of the N-type DBR reflective layer 2 and the P-type DBR reflective layer 10 , and the thickness is extremely small and can be ignored.

[0040] Specifically, the electron blocking layer 7 is composed of multiple groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The thickness of a superlattice structure is 20nm.0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The thickness of the P layer is 10 nm, where 0.05≤x2≤0.1 and y2>0.52, so that all tensile stresses (Al 1-x2 Ga x2 ) y2 In 1-y2 The bandwidth of the P layer is better than that of the Al 0.5 In 0.5 The upper limiting layer of P is 8 high, which can be referred to Figure 2 , will form a significant bandwidth difference, effectively blocking the overflow of carriers, further increasing the conversion efficiency and slope efficiency, and improving the high temperature performance; in addition, y2 gradually increases from the lower layer to the upper layer, which can be slowed down layer by layer (Al 1-x2 Ga x2 ) y2 In 1-y2 The tensile stress of the P layer achieves electron blocking effect while ensuring high-quality growth of the epitaxial layer.

[0041] Optionally, the electron blocking layer 7 is composed of 4 to 6 groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The superlattice structure consists of alternately grown P layers.

[0042] In the present invention, preferably 5 groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The superlattice structure of the alternately grown P layers forms the electron blocking layer 7. From bottom to top, the first layer of tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 y2 in the P layer is 0.54, y2 in the second layer is 0.56, y2 in the third layer is 0.58, y2 in the fourth layer is 0.60, and y2 in the fifth layer is 0.62.

[0043] Optionally, the substrate is a GaAs substrate, and specifically a GaAs substrate with a deflection angle of 15 degrees.

[0044] Optionally, the buffer layer 1 is a GaAs buffer layer with a thickness of 500 nm. The buffer layer 1 can connect the substrate with the subsequently grown epitaxial layer to reduce defects in the epitaxial layer.

[0045] Specifically, in the N-type DBR reflective layer 2 and the P-type DBR reflective layer 10, DBR (distributed Bragg reflective) is a reflector structure, which includes an adjustable multilayer structure composed of two optical materials, so that the N-type DBR reflective layer 2 and the P-type DBR reflective layer 10 are both formed by alternating growth of AlGaAs layers with high Al content and AlGaAs layers with low Al content, the Al content of the AlGaAs layer with high Al content ranges from 80% to 95%, and the Al content of the AlGaAs layer with low Al content ranges from 45% to 55%, and a 20nm transition layer is provided between the AlGaAs layers with high Al content and low Al content; wherein, the optical thickness of the AlGaAs layer with high Al content plus the transition layer is one quarter of the wavelength of the red light Vcsel emission laser, and the optical thickness of the AlGaAs layer with low Al content plus the transition layer is one quarter of the wavelength of the red light Vcsel emission laser.

[0046] Optionally, the number of alternating pairs of the high Al content AlGaAs layer and the low Al content AlGaAs layer of the N-type DBR reflective layer 2 is between 50-60 pairs, and the doping element is the N-type doping element Si; the number of alternating pairs of the high Al content AlGaAs layer and the low Al content AlGaAs layer of the P-type DBR reflective layer 10 is between 25-35 pairs, and the doping element is the P-type doping element C.

[0047] Optionally, the lower waveguide layer 4 and the upper waveguide layer 6 are both (Al 1-x 1Ga x1 ) y1 In 1-y1 P waveguide layer, and the thickness range is 50-100nm, where 0.2≤x1≤0.4, y1=0.5.

[0048] Specifically, the multi-quantum well layer 5 is composed of four groups of 7nm thick Ga x In 1-x P layer and 7nm thick (Al 1-x1 Ga x1 ) y1 In 1- y1 The P layers are alternately grown, wherein 0.4≤x≤0.6, 0.2≤x1≤0.4, y1=0.5, and the multi-quantum well layer 5 is placed at the peak of the resonant cavity layer to ensure maximum gain.

[0049] Optionally, the Al 0.5 In0.5 The thickness of the P top confinement layer 8 is in the range of 50-100 nm.

[0050] Furthermore, the resonant cavity layer also includes a 0.5 In 0.5 The oxide layer 9 between the P-type limiting layer 8 and the P-type DBR reflective layer 10 is Al 0.98 Ga 0.02 As oxide layer, thickness is 20nm, oxide layer 9 can limit current injection, and AlGaAs material with high Al content is easily oxidized by water vapor to generate AlO x It has good electrical insulation properties. In addition, AlO x The refractive index is low, and it can play the role of a refractive index waveguide, which can effectively limit the light beam. It should be noted that because the oxide layer 9 introduces oxygen elements and there are uncertain elements, the oxide layer 9 needs to be placed at the node position of the resonant cavity layer to ensure the minimization of light attenuation.

[0051] Furthermore, the red light Vcsel structure further includes an ohmic contact layer 11 located on the P-type DBR reflective layer 10, wherein the ohmic contact layer 11 is a highly doped GaAs ohmic contact layer with a thickness of 20 nm, and the doping element is a P-type doping element C, and the doping amount reaches 1E 20 cm -3 .

[0052] The present invention also provides a method for manufacturing a red light Vcsel structure, which specifically adopts a metal organic chemical vapor epitaxial deposition (MOCVD) method to sequentially grow a buffer layer 1, an N-type DBR reflective layer 2, a resonant cavity layer, a P-type DBR reflective layer 10, and an ohmic contact layer 11 on a substrate from bottom to top. The resonant cavity layer includes Al 0.5 In 0.5 P lower confinement layer 3, lower waveguide layer 4, multi-quantum well layer 5, upper waveguide layer 6, electron blocking layer 7, Al 0.5 In 0.5 A limiting layer 8 and an oxide layer 9 are formed on P, and the resonant cavity layer satisfies: nL=mλ / 2, wherein n is the average refractive index of the resonant cavity layer, L is the length of the resonant cavity layer, λ is the resonant wavelength, and m is 3.

[0053] Please refer to Figure 3 The manufacturing method of the red light Vcsel structure specifically comprises the following steps:

[0054] S1. Growing a buffer layer 1 on a substrate.

[0055] Optionally, the substrate is a GaAs substrate with a deflection angle of 15 degrees, and the buffer layer 1 is a GaAs buffer layer with a growth thickness of 500 nm, which is used to connect the substrate with a subsequently grown epitaxial layer to reduce defects in the epitaxial layer.

[0056] S2 . Growing an N-type DBR reflective layer 2 on the buffer layer 1 .

[0057] Specifically, the N-type DBR reflective layer 2 is formed by alternatingly growing an AlGaAs layer with a high Al content and an AlGaAs layer with a low Al content, the Al content of the AlGaAs layer with a high Al content is in the range of 80%-95%, the Al content of the AlGaAs layer with a low Al content is in the range of 45%-55%, and a 20nm transition layer is provided between the AlGaAs layers with a high Al content and the AlGaAs layers with a low Al content; wherein the optical thickness of the AlGaAs layer with a high Al content plus the transition layer is one quarter of the wavelength of the red light Vcsel emission laser, and the optical thickness of the AlGaAs layer with a low Al content plus the transition layer is one quarter of the wavelength of the red light Vcsel emission laser.

[0058] Optionally, the number of alternating pairs of the high Al content AlGaAs layer and the low Al content AlGaAs layer of the N-type DBR reflective layer 2 is between 50 and 60 pairs, and the doping element is the N-type doping element Si.

[0059] S3, growing Al on the N-type DBR reflective layer 2 0.5 In 0.5 P lower confinement layer 3.

[0060] Specifically, the Al 0.5 In 0.5 The growth thickness of the P lower confinement layer 3 is between 150-200nm. Because the resonant cavity layer adopts a long cavity length structure of 3 times the cavity length, Al 0.5 In 0.5 The growth thickness of the P lower confinement layer 3 is more than three times that of the conventional short cavity length structure with m being 1, which effectively limits the overflow of carriers, increases the conversion efficiency and slope efficiency, and improves the high temperature performance.

[0061] S4. In Al 0.5 In 0.5 A lower waveguide layer 4 is grown on the P lower confinement layer 3 .

[0062] Optionally, the growth material of the lower waveguide layer 4 is (Al 1-x 1Ga x1 ) y1 In 1-y1 P, and the growth thickness is between 50-100nm, where 0.2≤x1≤0.4, y1=0.5.

[0063] S5 . Growing a multi-quantum well layer 5 on the lower waveguide layer 4 .

[0064] Specifically, the growth material of the multi-quantum well layer 5 includes Ga x In 1-x P and (Al 1-x1 Ga x1 ) y1 In 1-y1 P, composed of 4 groups of Ga x In 1-x P layer and (Al 1-x1 Ga x1 ) y1 In 1-y1 P layers are alternately grown, where 0.4≤x≤0.6, 0.2≤x1≤0.4, y1=0.5, and each group of Ga x In 1-x P layer and (Al 1-x1 Ga x1 ) y1 In 1-y1 The growth thickness of the P layer is 7nm, and the multi-quantum well layer is placed at the peak of the resonant cavity layer to ensure maximum gain.

[0065] S6 . Growing an upper waveguide layer 6 on the multi-quantum well layer 5 .

[0066] Optionally, the growth material of the upper waveguide layer 6 is (Al 1-x 1Ga x1 ) y1 In 1-y1 P, and the growth thickness is between 50-100nm, where 0.2≤x1≤0.4, y1=0.5.

[0067] S7 . Growing an electron blocking layer 7 on the upper waveguide layer 6 .

[0068] Specifically, the electron blocking layer 7 is composed of multiple groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The superlattice structure consists of an alternating growth of P layers. The growth thickness of a superlattice structure is 20nm. 0.5 In 0.5 P layer and tensile stress Al 1-x2 Ga x2 ) y2 In 1-y2 The growth thickness of the P layer is 10 nm, where 0.05≤x2≤0.1 and y2>0.52, so that all tensile stresses (Al 1-x2 Gax2 ) y2 In 1-y2 The bandwidth of the P layer is larger than that of the subsequently grown Al 0.5 In 0.5 The upper limiting layer of P is 8 high, which can be referred to Figure 2 , will form a significant bandwidth difference, effectively blocking the overflow of carriers. In addition, the tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The y2 in the P layer increases gradually from the lower layer to the upper layer, and can be slowed down layer by layer (Al 1-x2 Ga x2 ) y2 In 1-y2 The tensile stress of the P layer achieves electron blocking effect while ensuring high-quality growth of the epitaxial layer.

[0069] Optionally, the electron blocking layer 7 is composed of 4 to 6 groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 P layers are grown alternately. 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The superlattice structure of the alternately grown P layers forms the electron blocking layer 7. From bottom to top, the first layer of tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 y2 in the P layer is 0.54, y2 in the second layer is 0.56, y2 in the third layer is 0.58, y2 in the fourth layer is 0.60, and y2 in the fifth layer is 0.62.

[0070] S8. Growing Al on the electron blocking layer 7 0.5 In 0.5 P has a confinement layer 8 on it.

[0071] Optionally, the Al 0.5 In 0.5 The growth thickness of the P top confinement layer 8 is between 50-100 nm.

[0072] S9, in Al 0.5 In 0.5 An oxide layer 9 is grown on the P upper confinement layer 8 .

[0073] Specifically, the growth material of the oxide layer 9 is Al0.98 Ga 0.02 As, the growth thickness is 20nm, the oxide layer 9 can limit the current injection, and the AlGaAs material with high Al content is easily oxidized by water vapor to generate AlO x It has good electrical insulation properties. In addition, AlO x The refractive index is low, and it can play the role of a refractive index waveguide, which can effectively limit the light beam. It should be noted that because the oxide layer 9 introduces oxygen elements and there are uncertain elements, the oxide layer 9 needs to be placed at the node position of the resonant cavity layer to ensure the minimization of light attenuation.

[0074] S10 , growing a P-type DBR reflective layer 10 on the oxide layer 9 .

[0075] Specifically, the growth material of the P-type DBR reflective layer 10 is the same as that of the N-type DBR reflective layer 2, and both are formed by alternating growth of AlGaAs layers with high Al content and AlGaAs layers with low Al content, and the Al content and growth thickness of the high Al content AlGaAs layers and the low Al content AlGaAs layers are also the same as those of the N-type DBR reflective layer 2.

[0076] Optionally, the number of alternating pairs of the high Al content AlGaAs layer and the low Al content AlGaAs layer of the P-type DBR reflective layer 10 is between 25 and 35 pairs, and the doping element is the P-type doping element C.

[0077] S11 , growing an ohmic contact layer 11 on the P-type DBR reflective layer 10 .

[0078] Optionally, the growth material of the ohmic contact layer 11 is GaAs, the growth thickness is 20nm, the doping element is a P-type doping element C, and the doping amount reaches 1E 20 cm -3 , which is a highly doped GaAs ohmic contact layer.

[0079] In summary, the present invention provides a red light Vcsel structure and a manufacturing method thereof. The resonant cavity layer of the red light Vcsel structure satisfies nL=mλ / 2, m is 3, and is a long cavity length structure, so that Al 0.5 In 0.5 The thickness of the P lower limiting layer 3 is more than 3 times thicker than the conventional short cavity length structure with m being 1, which can effectively limit the overflow of carriers, increase the conversion efficiency and slope efficiency, and improve the high temperature performance. In addition, an electron blocking layer 7 is added, which is composed of multiple groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2The superlattice structure consists of an alternating growth of P layers, in which y2 increases gradually from the lower layer to the upper layer, and can be slowed down layer by layer (Al 1-x2 Ga x2 ) y2 In 1-y2 The tensile stress of the P layer ensures the high-quality growth of the epitaxial layer while achieving the electron blocking effect. In addition, 0.05≤x2≤0.1, and all y2 are greater than 0.52, making all tensile stresses (Al 1-x2 Ga x2 ) y2 In 1-y2 The bandwidth of the P layer is better than that of the Al 0.5 In 0.5 The P upper confinement layer 8 is high, forming an obvious bandwidth difference, effectively blocking the overflow of carriers, further increasing the conversion efficiency and slope efficiency, and improving the high temperature performance.

[0080] It is worth noting that the buffer layer 1, the N-type DBR reflective layer 2, and the Al 0.5 In 0.5 P lower confinement layer 3, lower waveguide layer 4, multi-quantum well layer 5, upper waveguide layer 6, electron blocking layer 7, Al 0.5 In 0.5 The thickness of the P-type limiting layer 8, the oxide layer 9, the P-type DBR reflective layer 10, and the ohmic contact layer 11 are only examples and do not represent their actual thicknesses. 0.5 In 0.5 P lower confinement layer 3, lower waveguide layer 4, multi-quantum well layer 5, upper waveguide layer 6, electron blocking layer 7, Al 0.5 In 0.5 The actual proportions among the P-type confinement layer 8, the oxide layer 9, the P-type DBR reflective layer 10, and the ohmic contact layer 11 are also not as shown in the drawings, and are for reference only.

[0081] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0082] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A red light Vcsel structure, characterized in that: It includes a substrate, a buffer layer, an N-type DBR reflective layer, a resonant cavity layer and a P-type DBR reflective layer stacked in sequence from bottom to top; The resonant cavity layer includes Al 0.5 In 0.5 P lower confinement layer, lower waveguide layer, multi-quantum well layer, upper waveguide layer, electron blocking layer, Al 0.5 In 0.5 P upper restriction layer; The resonant cavity layer satisfies: nL=mλ / 2, where n is the average refractive index of the resonant cavity layer, L is the length of the resonant cavity layer, λ is the resonant wavelength, and m is 3; The electron blocking layer is composed of multiple groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The superlattice structure is composed of alternately grown P layers, wherein 0.05≤x2≤0.1, y2>0.52, and y2 gradually increases from the lower layer to the upper layer.

2. A red light Vcsel structure as claimed in claim 1, characterized in that: The electron blocking layer is composed of 4 to 6 groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The thickness of a superlattice structure is 20nm. 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The thickness of the P layers was 10 nm each.

3. A red light Vcsel structure as claimed in claim 1 or 2, characterized in that: The electron blocking layer is composed of 5 groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 The superlattice structure consists of an alternating growth of P layers, with the first layer of tensile stress (Al 1-x2 Ga x2 ) y2 In 1-y2 y2 in the P layer is 0.54, y2 in the second layer is 0.56, y2 in the third layer is 0.58, y2 in the fourth layer is 0.60, and y2 in the fifth layer is 0.

62.

4. A red light Vcsel structure as claimed in claim 1, characterized in that: The N-type DBR reflective layer and the P-type DBR reflective layer are formed by alternatingly growing an AlGaAs layer with a high Al content and an AlGaAs layer with a low Al content, wherein the Al content of the AlGaAs layer with a high Al content is in the range of 80%-95%, and the Al content of the AlGaAs layer with a low Al content is in the range of 45%-55%, and a 20nm transition layer is provided between the AlGaAs layer with a high Al content and the AlGaAs layer with a low Al content; wherein the optical thickness of the AlGaAs layer with a high Al content plus the transition layer is one quarter of the wavelength of the red light Vcsel emission laser, and the optical thickness of the AlGaAs layer with a low Al content plus the transition layer is one quarter of the wavelength of the red light Vcsel emission laser.

5. A red light Vcsel structure as claimed in claim 4, characterized in that: The alternating number of pairs of the high Al content AlGaAs layer and the low Al content AlGaAs layer of the N-type DBR reflective layer is between 50-60 pairs, and the doping element is the N-type doping element Si; the alternating number of pairs of the high Al content AlGaAs layer and the low Al content AlGaAs layer of the P-type DBR reflective layer is between 25-35 pairs, and the doping element is the P-type doping element C.

6. A red light Vcsel structure as claimed in claim 1, characterized in that: The multi-quantum well layer consists of four groups of 7nm thick Ga x In 1-x P layer and 7nm thick (Al 1-x1 Ga x1 ) y1 In 1-y1 The P layers are formed by alternating growth, where 0.4≤x≤0.6, 0.2≤x1≤0.4, and y1=0.

5.

7. A red light Vcsel structure as claimed in claim 1, characterized in that: The lower waveguide layer and the upper waveguide layer are (Al 1-x 1Ga x1 ) y1 In 1-y1 P waveguide layer, and the thickness range is 50-100nm, where 0.2≤x1≤0.4, y1=0.

5.

8. A red light Vcsel structure as claimed in claim 1, characterized in that: The Al 0.5 In 0.5 The thickness of the P lower confinement layer ranges from 150 to 200 nm. 0.5 In 0.5 The thickness of the P confinement layer ranges from 50 to 100 nm.

9. A red light Vcsel structure as claimed in claim 1, characterized in that: The resonant cavity layer also includes an Al 0.5 In 0.5 The oxide layer between the P-type limiting layer and the P-type DBR reflective layer is Al 0.98 Ga 0.02 As oxide layer, thickness is 20nm.

10. A method for manufacturing a red light Vcsel structure, characterized in that: include: growing a buffer layer on the substrate; Growing an N-type DBR reflective layer on the buffer layer; Growing Al on the reflective layer of N-type DBR 0.5 In 0.5 P lower limiting layer; In Al 0.5 In 0.5 A lower waveguide layer is grown on the P lower confinement layer; growing a multi-quantum well layer on the lower waveguide layer; growing an upper waveguide layer on the multiple quantum well layer; An electron blocking layer is grown on the upper waveguide layer. The electron blocking layer is composed of multiple groups of Al 0.5 In 0.5 P layer and tensile stress (Al 1- x2 Ga x2 ) y2 In 1-y2 The P layers are formed by alternating growth, where 0.05≤x2≤0.1, y2>0.52, and y2 increases gradually from the lower layer to the upper layer; Growth of Al on the electron blocking layer 0.5 In 0.5 P upper confinement layer, the Al 0.5 In 0.5 P lower confinement layer, lower waveguide layer, multi-quantum well layer, upper waveguide layer, electron blocking layer and Al 0.5 In 0.5 The upper limiting layer P forms a resonant cavity layer, and the resonant cavity layer satisfies: nL=mλ / 2, wherein n is the average refractive index of the resonant cavity layer, L is the length of the resonant cavity layer, λ is the resonant wavelength, and m is 3; In Al 0.5 In 0.5 A P-type DBR reflective layer is grown on the P upper confinement layer.

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