Semiconductor laser structure with strain layer
By setting up the strain layer from one side of the cushion layer of the semiconductor laser, the strain layer of the traditional laser extension structure has been solved, which causes serious warriors and seriously lead to the effect of reducing warning, reducing fragmentation rate, and improving yields.
Patent Information
- Application Number
- CN202411768767.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-01-21
AI Technical Summary
The buffer layer of the epitaxial structure of the traditional high-power laser causes large stress accumulation, resulting in severe warping, affecting the reliability of the laser.
Set the strain layer on one side of the buffer layer away from the side of the substrate. The material is alxga1-xinyp. The stress size is adjusted by adjusting the proportion of the 铟 component, which contrary to the pressure stress of the laser extension structure, thereby balance the stress of the entire extension structure.
Through the introduction of the strain layer, the levelation of the outer lattice is reduced, the fragmentation rate is reduced, the diarrhea pattern is reduced, the yield is improved, and the stress problem of the laser extension structure is improved.
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Figure CN119340786A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor technology, and in particular to a semiconductor laser structure with a strained layer. Background Art
[0002] The buffer layer of the traditional high-power laser epitaxial structure is mostly made of gallium arsenide material. In addition to the buffer layer, the structure is usually made of gallium arsenide aluminum materials with different aluminum contents. Although the lattice parameters of aluminum arsenide and gallium arsenide are very close, 5.6691Å and 5.6533Å respectively, and the lattice mismatch is 1500ppm, the total thickness of the aluminum-containing part of the entire laser epitaxial structure is between 4-10μm, resulting in a large total compressive stress accumulation.
[0003] According to the test, the warpage of 4-inch epitaxial wafers is 20μm when the substrate is 625-675μm; if the substrate is thinned to 150μm, the warpage reaches about 260μm. For 6-inch epitaxial wafers, the warpage is 150μm when the substrate is not thinned. If the substrate is thinned to 150μm, the warpage is extremely serious and it is easy to break. Even if it does not break, cavity lines are easily generated during cleavage, resulting in failure of cavity surface reliability. Summary of the invention
[0004] In order to improve the defect of large compressive stress in the laser epitaxial structure, which leads to severe warping, the present application provides a semiconductor laser structure with a strained layer.
[0005] The present application provides a semiconductor laser structure with a strained layer, which adopts the following technical solution: A semiconductor laser structure with a strained layer comprises an epitaxial structure layer and a substrate, wherein the epitaxial structure layer comprises a buffer layer, wherein the material of the buffer layer is gallium arsenide, and a strained layer is arranged on a side of the buffer layer away from the substrate, wherein the material of the strained layer is Al x Ga 1-x In y P, where 0 <x<1,0<y<0.48。
[0006] By adopting the above technical solution, a strain layer is set on the side of the buffer layer away from the substrate, and the stress is adjusted by adjusting the proportion of indium components. When y=0.48, Al x Ga 1-x In y P is lattice matched with GaAs. When y < 0.48, Al x Ga 1-x In yThe lattice of P is smaller than that of gallium arsenide. A tensile stress opposite to the compressive stress of the laser epitaxial structure is introduced into the structure, so that the stress of the entire epitaxial structure is balanced, the warping of the epitaxial wafer is reduced, the fragmentation rate is reduced, the cavity lines are cleaved, the yield is improved, and the defect of severe warping caused by large compressive stress of the laser epitaxial structure is improved.
[0007] Optionally, the epitaxial growth temperature of the strained layer is 600-750° C., and the epitaxial growth pressure is 80-200 mbar.
[0008] Optionally, the epitaxial growth of the strained layer adopts PH3 thermal decomposition, and the flow rate of PH3 is 300-2000sccm.
[0009] Optionally, a semiconductor laser structure with a strained layer further includes a contact layer, a P-face confinement layer, a P-face waveguide layer, an active layer, an N-face waveguide layer and an N-face confinement layer arranged in sequence, wherein the N-face confinement layer is located on a side of the strained layer away from the buffer layer.
[0010] Optionally, the materials of the N-side limiting layer and the N-side waveguide layer are both GaAs Al, and the N-side limiting layer and the N-side waveguide layer are doped with silicon, and the doping concentration of silicon is 5×10 16 -3×10 18 cm -3 The epitaxial growth temperature of the N-side confinement layer and the N-side waveguide layer is 600-750° C., and the epitaxial growth pressure is 80-200 mbar.
[0011] Optionally, the epitaxial growth of the N-side confinement layer and the N-side waveguide layer is performed by thermal decomposition of AsH3, the flow rate of AsH3 is 300-2000 sccm, and the total thickness of the N-side confinement layer and the N-side waveguide layer is 1-5 μm.
[0012] Optionally, the material of the active layer is indium gallium aluminum, the epitaxial growth temperature of the active layer is 580-750° C., the epitaxial growth pressure is 80-200 mbar, and the thickness is 2-10 nm.
[0013] Optionally, the materials of the P-plane limiting layer and the P-plane waveguide layer are both gallium aluminum arsenide, and the P-plane limiting layer and the P-plane waveguide layer are doped with carbon, and the carbon doping concentration is 5×10 16 -3×10 18 cm -3 The epitaxial growth temperature of the P-face limiting layer and the P-face waveguide layer is 600-750° C., the epitaxial growth pressure is 80-200 mbar, and the total thickness of the P-face limiting layer and the P-face waveguide layer is 1-5 μm.
[0014] Optionally, the epitaxial growth of the P-face confinement layer and the P-face waveguide layer is performed by thermal decomposition of AsH3, and the flow rate of AsH3 is 300-2000sccm.
[0015] Optionally, the material of the contact layer is gallium arsenide phosphorus, and the contact layer is doped with carbon, and the carbon doping concentration is 5×10 19 -5×10 20 cm -3 The epitaxial growth temperature of the contact layer is 550-650° C., the epitaxial growth pressure is 80-200 mbar, and the thickness is 50-500 nm.
[0016] In summary, the present application includes at least one of the following beneficial technical effects: A strain layer is set on the side of the buffer layer away from the substrate, and the stress is adjusted by adjusting the proportion of indium components. When y=0.48, Al x Ga 1-x In y P is lattice matched with GaAs. When y < 0.48, Al x Ga 1-x In y The lattice of P is smaller than that of gallium arsenide. A tensile stress opposite to the compressive stress of the laser epitaxial structure is introduced into the structure, so that the stress of the entire epitaxial structure is balanced, the warping of the epitaxial wafer is reduced, the fragmentation rate is reduced, the cavity lines are cleaved, the yield is improved, and the defect of severe warping caused by large compressive stress of the laser epitaxial structure is improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a structural schematic diagram of a semiconductor laser structure with a strained layer according to an embodiment of the present application.
[0018] Explanation of the accompanying drawings: 1. contact layer; 2. P-side confinement layer; 3. P-side waveguide layer; 4. active layer; 5. N-side waveguide layer; 6. N-side confinement layer; 7. strain layer; 8. buffer layer; 9. substrate. DETAILED DESCRIPTION
[0019] The following is combined with Figure 1 This application is described in further detail.
[0020] Example
[0021] The embodiment of the present application discloses a semiconductor laser structure with a strained layer.
[0022] Example 1
[0023] Reference Figure 1A semiconductor laser structure with a strained layer includes a contact layer 1, a P-face confinement layer 2, a P-face waveguide layer 3, an active layer 4, an N-face waveguide layer 5, an N-face confinement layer 6, a strained layer 7, a buffer layer 8 and a substrate 9 which are arranged in sequence.
[0024] The material of the contact layer 1 is gallium arsenide phosphorus, and the contact layer 1 is doped with carbon, and the doping concentration of carbon is 5×10 19 -5×10 20 cm -3 , the epitaxial growth temperature is 550-650°C, the epitaxial growth pressure is 80-200 mbar, and the thickness is 50-500 nm. In this embodiment, the carbon doping concentration of the contact layer 1 is 5×10 19 cm -3 , the epitaxial growth temperature is 550°C, the epitaxial growth pressure is 200mbar, and the thickness is 200nm.
[0025] The material of the P-plane restriction layer 2 is gallium aluminum arsenide, and the P-plane restriction layer 2 is fixedly connected to the contact layer 1. The P-plane restriction layer 2 is doped with carbon, and the doping concentration of carbon is 5×10 16 -3×10 18 cm -3 The epitaxial growth of the P-face limiting layer 2 is carried out by thermal decomposition of AsH3, the flow rate of AsH3 is 300-2000sccm, the epitaxial growth temperature of the P-face limiting layer 2 is 600-750°C, and the epitaxial growth pressure is 80-200mbar. In this embodiment, the material of the P-face limiting layer 2 is Al 0.2 GaAs. The carbon doping concentration of the P-surface confinement layer 2 is 5×10 16 cm -3 , the flow rate of AsH3 is 2000sccm, the epitaxial growth temperature is 600℃, the epitaxial growth pressure is 200mbar, and the thickness is 500nm.
[0026] The material of the P-plane waveguide layer 3 is gallium aluminum arsenide, and the P-plane waveguide layer 3 is fixedly connected to the P-plane limiting layer 2. The P-plane waveguide layer 3 is doped with carbon, and the doping concentration of carbon is 5×10 16 -3×10 18 cm -3 The epitaxial growth of the P-face waveguide layer 3 is carried out by thermal decomposition of AsH3, the flow rate of AsH3 is 300-2000sccm, the epitaxial growth temperature of the P-face waveguide layer 3 is 600-750°C, the epitaxial growth pressure is 80-200mbar, and the total thickness of the P-face confinement layer 2 and the P-face waveguide layer 3 is 1-5μm. In this embodiment, the material of the P-face waveguide layer 3 is Al 0.4 GaAs. The carbon doping concentration of the P-side waveguide layer 3 is 3×10 18 cm -3, the flow rate of AsH3 is 2000sccm, the epitaxial growth temperature is 750℃, the epitaxial growth pressure is 200mbar, and the thickness is 1000nm.
[0027] The material of the active layer 4 is indium gallium arsenide, and the active layer 4 is fixedly connected to the P-side waveguide layer 3. The epitaxial growth of the active layer 4 adopts AsH3 thermal decomposition, the flow rate of AsH3 is 50-100 sccm, the epitaxial growth temperature of the active layer 4 is 580-750°C, the epitaxial growth pressure is 80-200 mbar, and the thickness is 2-10 nm. In this embodiment, the material of the active layer 4 is In 0.08 GaAs. The epitaxial growth temperature of the active layer 4 is 580° C., the epitaxial growth pressure is 80 mbar, the thickness is 6 nm, and the flow rate of AsH3 is 100 sccm.
[0028] The material of the N-side waveguide layer 5 is gallium aluminum arsenide, and the N-side waveguide layer 5 is fixedly connected to the active layer 4. The N-side waveguide layer 5 is doped with silicon, and the doping concentration of silicon is 5×10 16 -3×10 18 cm -3 The epitaxial growth of the N-side waveguide layer 5 is carried out by thermal decomposition of AsH3, the flow rate of AsH3 is 300-2000 sccm, the epitaxial growth temperature of the N-side waveguide layer 5 is 600-750°C, and the epitaxial growth pressure is 80-200 mbar. In this embodiment, the material of the N-side waveguide layer 5 is Al 0.4 GaAs. The silicon doping concentration of the N-side waveguide layer 5 is 5×10 16 cm -3 , the flow rate of AsH3 is 2000sccm, the epitaxial growth temperature is 600℃, the epitaxial growth pressure is 200mbar, and the thickness is 1000nm.
[0029] The material of the N-side limiting layer 6 is gallium aluminum arsenide, and the N-side limiting layer 6 is fixedly connected to the N-side waveguide layer 5. The N-side limiting layer 6 is doped with silicon, and the doping concentration of silicon is 5×10 16 -3×10 18 cm -3 The epitaxial growth of the N-side limiting layer 6 is carried out by thermal decomposition of AsH3, the flow rate of AsH3 is 300-2000sccm, the epitaxial growth temperature of the N-side limiting layer 6 is 600-750°C, the epitaxial growth pressure is 80-200mbar, and the thickness is 1-5μm. In this embodiment, the material of the N-side limiting layer 6 is Al 0.2 GaAs. The silicon doping concentration of the N-face confinement layer 6 is 5×10 16 cm -3 , the flow rate of AsH3 is 2000sccm, the epitaxial growth temperature is 750℃, the epitaxial growth pressure is 200mbar, and the thickness is 500nm.
[0030] The material of the strain layer 7 is Al x Ga 1-x In y P, where 0 < x < 1, 0 < y < 0.48, and the strain layer 7 is fixedly connected to the N-side confinement layer 6. The epitaxial growth of the strain layer 7 uses the thermal decomposition of PH3, and the flow rate of PH3 is 300 - 2000 sccm. The epitaxial growth temperature of the strain layer 7 is 600 - 750 °C, and the epitaxial growth pressure is 80 - 200 mbar. In this embodiment, the material of the strain layer 7 is Al 0.3 Ga 0.7 In 0.1 P, the flow rate of PH3 is 2000 sccm. The epitaxial growth temperature of the strain layer 7 is 650 °C, and the epitaxial growth pressure is 100 mbar.
[0031] The material of the buffer layer 8 is gallium arsenide, and the buffer layer 8 is fixedly connected to the strain layer 7. In this embodiment, the thickness of the buffer layer 8 is 200 nm.
[0032] The material of the substrate 9 is gallium arsenide, and the substrate 9 is fixedly connected to the buffer layer 8. In this embodiment, the size of the substrate 9 is 4 inches, and the thickness is 650 μm. The sizes of the contact layer 1, P-side confinement layer 2, P-side waveguide layer 3, active layer 4, N-side waveguide layer 5, N-side confinement layer 6, strain layer 7, and buffer layer 8 are all equal to that of the substrate 9.
[0033] In this embodiment, the total compressive stress generated by the contact layer 1, P-side confinement layer 2, P-side waveguide layer 3, active layer 4, N-side waveguide layer 5, and N-side confinement layer 6 is 283 ppm × 500 nm + 567 ppm × 1000 nm + 5731 ppm × 6 nm + 567 ppm × 1000 nm + 283 ppm × 500 nm = 1451386.
[0034] Since the material of the strain layer 7 is Al 0.3 Ga 0.7 In 0.1 P, through the XRD analysis software, it can be obtained that the stress difference between the strain layer 7 and the buffer layer 8 is -27839 ppm. Then, in this embodiment, the thickness of the strain layer 7 is 1451386 / 27839 = 52 nm.
[0035] At this time, the tensile stress generated between the strain layer 7 and the buffer layer 8 is balanced with the total compressive stress of the semiconductor laser structure, reducing the warping of the epitaxial wafer, reducing the fragmentation rate, cleavage cavity pattern, improving the yield rate, and improving the defect that the large compressive stress of the laser epitaxial structure causes serious warping.
[0036] Embodiment 2
[0037] The difference between Example 2 and Example 1 is that the values of x and y are different, resulting in a different thickness of the strain layer 7 .
[0038] In this embodiment, the material of the strain layer 7 is Al 0.4 Ga 0.6 In 0.1 P, it can be obtained through XRD analysis software that the stress difference between the strain layer 7 and the buffer layer 8 is -27629ppm, so in this embodiment, the thickness of the strain layer 7 is 1451386 / 27629=53nm.
[0039] Example 3
[0040] The difference between Example 3 and Example 1 is that the values of x and y are different, resulting in a different thickness of the strain layer 7 .
[0041] In this embodiment, the material of the strain layer 7 is Al 0.1 Ga 0.9 In 0.45 P, it can be obtained through XRD analysis software that the stress difference between the strain layer 7 and the buffer layer 8 is -2370ppm. In this embodiment, the thickness of the strain layer 7 is 1451386 / 2370=612nm.
[0042] Example 4
[0043] The difference between Example 4 and Example 1 is that the values of x and y are different, resulting in a different thickness of the strain layer 7 .
[0044] In this embodiment, the material of the strain layer 7 is Al 0.3 Ga 0.7 In 0.45 P, it can be obtained through XRD analysis software that the stress difference between the strain layer 7 and the buffer layer 8 is -2160ppm, so in this embodiment, the thickness of the strain layer 7 is 1451386 / 2160=672nm.
[0045] Combining Examples 1-4, it can be seen that the thickness of the strain layer 7 is determined by the stress difference between the strain layer 7 and the buffer layer 8, and the total compressive stress generated by the contact layer 1, the P-face confinement layer 2, the P-face waveguide layer 3, the active layer 4, the N-face waveguide layer 5 and the N-face confinement layer 6. The stress difference between the strain layer 7 and the buffer layer 8 is determined by the values of x and y. It can be concluded from the XRD analysis software that when y<0.48, Al x Ga 1-x In yThe lattice of P is smaller than that of GaAs, which generates tensile stress between the strain layer 7 and the buffer layer 8. The tensile stress opposite to the compressive stress of the laser epitaxial structure is introduced into the structure to balance the stress of the entire epitaxial structure, reduce the warping of the epitaxial wafer, reduce the fragmentation rate, cleave the cavity lines, improve the yield, and improve the defect of the laser epitaxial structure with large compressive stress and severe warping.
[0046] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.
Claims
1. A semiconductor laser structure with a strained layer, comprising an epitaxial structure layer and a substrate (9), characterized in that: The epitaxial structure layer comprises a buffer layer (8), the material of the buffer layer (8) is gallium arsenide, and a strain layer (7) is provided on a side of the buffer layer (8) away from the substrate (9), and the material of the strain layer (7) is Al x Ga 1-x In y P, where 0 <x<1,0<y<0.48。 2. The semiconductor laser structure with a strained layer according to claim 1, characterized in that: The epitaxial growth temperature of the strained layer (7) is 600-750° C., and the epitaxial growth pressure is 80-200 mbar.
3. The semiconductor laser structure with a strained layer according to claim 2, characterized in that: The epitaxial growth of the strained layer (7) adopts PH3 thermal decomposition, and the flow rate of PH3 is 300-2000sccm.
4. The semiconductor laser structure with a strained layer according to claim 1, characterized in that: It also includes a contact layer (1), a P-face limiting layer (2), a P-face waveguide layer (3), an active layer (4), an N-face waveguide layer (5) and an N-face limiting layer (6) which are arranged in sequence, wherein the N-face limiting layer (6) is located on a side of the strain layer (7) away from the buffer layer (8).
5. The semiconductor laser structure with a strained layer according to claim 4, characterized in that: The materials of the N-side limiting layer (6) and the N-side waveguide layer (5) are both gallium aluminum arsenide, the epitaxial growth temperature of the N-side limiting layer (6) and the N-side waveguide layer (5) is 600-750° C., and the epitaxial growth pressure is 80-200 mbar.
6. The semiconductor laser structure with a strained layer according to claim 5, characterized in that: The epitaxial growth of the N-side limiting layer (6) and the N-side waveguide layer (5) is carried out by thermal decomposition of AsH3, with the flow rate of AsH3 being 300-2000sccm.
7. The semiconductor laser structure with a strained layer according to claim 4, characterized in that: The material of the active layer (4) is indium gallium aluminum, the epitaxial growth temperature of the active layer (4) is 580-750° C., and the epitaxial growth pressure is 80-200 mbar.
8. The semiconductor laser structure with a strained layer according to claim 4, characterized in that: The materials of the P-face limiting layer (2) and the P-face waveguide layer (3) are both gallium aluminum arsenide, the epitaxial growth temperature of the P-face limiting layer (2) and the P-face waveguide layer (3) is 600-750° C., and the epitaxial growth pressure is 80-200 mbar.
9. The semiconductor laser structure with a strained layer according to claim 8, characterized in that: The epitaxial growth of the P-face limiting layer (2) and the P-face waveguide layer (3) is carried out by thermal decomposition of AsH3, and the flow rate of AsH3 is 300-2000sccm.
10. The semiconductor laser structure with a strained layer according to claim 1, characterized in that: The material of the contact layer (1) is gallium arsenide phosphide, the epitaxial growth temperature of the contact layer (1) is 550-650° C., and the epitaxial growth pressure is 80-200 mbar.