A gallium nitride-based semiconductor laser and a method for preparing the same

Abstract

The present invention proposes a gallium nitride-based semiconductor laser and a preparation method, comprising a single crystal substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper confinement layer arranged in sequence from bottom to top, and a p-type contact layer is arranged above the upper confinement layer, and the p-type contact layer has peak rate electric field distribution characteristics, transverse sound velocity distribution characteristics and saturated electron drift rate distribution characteristics. The present invention arranges a p-type contact layer having peak rate electric field distribution characteristics, transverse sound velocity distribution characteristics and saturated electron drift rate distribution characteristics above the upper confinement layer of the gallium nitride-based semiconductor laser, which can improve the hole mobility and hole transport efficiency, thereby improving the hole expansion capacity of the p-type contact layer, and then improving the ESD of the laser and reducing the voltage. At the same time, the Joule heat loss generated by the p-type contact layer of the laser is reduced, the heat accumulation and temperature rise of the laser are reduced, the thermal red shift of the laser is improved, and the life and reliability of the laser are improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor optoelectronic devices, and in particular to a gallium nitride-based semiconductor laser and a preparation method thereof. Background Art

[0002] Lasers are widely used in laser display, laser TV, laser projector, communication, medical treatment, weapons, guidance, ranging, spectral analysis, cutting, precision welding, high-density optical storage and other fields. There are many types of lasers, and the classification methods are also diverse, mainly including solid, gas, liquid, semiconductor and dye types of lasers; compared with other types of lasers, all-solid-state semiconductor lasers have the advantages of small size, high efficiency, light weight, good stability, long life, simple and compact structure, and miniaturization.

[0003] There are big differences between lasers and nitride semiconductor light-emitting diodes:

[0004] 1) Laser is generated by stimulated radiation of carriers, the spectrum half-width is small, the brightness is very high, and the output power of a single laser can be in the W level, while nitride semiconductor light-emitting diodes are spontaneously radiated, and the output power of a single light-emitting diode is in the mW level;

[0005] 2) The current density of the laser reaches KA / cm2, which is more than 2 orders of magnitude higher than that of nitride light-emitting diodes, resulting in stronger electron leakage, more serious Auger recombination, stronger polarization effect, more serious electron-hole mismatch, and more serious efficiency attenuation Droop effect;

[0006] 3) The spontaneous transition radiation of the light-emitting diode is incoherent light that transitions from a high energy level to a low energy level without any external influence, while the laser is stimulated transition radiation, and the energy of the induced photon should be equal to the difference in the energy level of the electron transition, producing the same coherent light as the photon and the induced photon;

[0007] 4) Different principles: When an external voltage is applied to a light-emitting diode, electron holes jump to a quantum well or a pn junction to generate radiative recombination light, while a laser can only emit when the lasing conditions are met. The carrier distribution in the active region must be reversed, and the stimulated radiation light oscillates back and forth in the resonant cavity. The propagation in the gain medium amplifies the light, and the threshold condition is met so that the gain is greater than the loss, and finally the laser is output.

[0008] Semiconductor lasers have the following problems: the Mg acceptor activation energy of the laser's p-type semiconductor is large, the ionization efficiency is low, the hole concentration is much lower than the electron concentration, the hole mobility is much lower than the electron mobility, and the hole transport is poor, resulting in poor hole expansion in the p-type contact layer, poor ESD capability and high voltage. At the same time, under current injection, the p-type contact layer will produce Joule heat loss, resulting in heat accumulation and temperature rise in the laser, causing the laser to experience problems such as red shift in lasing wavelength, shortened life and poor reliability. Summary of the invention

[0009] In order to solve one of the above technical problems, the present invention provides a gallium nitride-based semiconductor laser and a preparation method thereof.

[0010] A first aspect of an embodiment of the present invention provides a method for preparing a gallium nitride-based semiconductor laser, the method comprising:

[0011] A single crystal substrate is used as a substrate;

[0012] Placing the single crystal substrate in a MOCVD reaction chamber;

[0013] Regulating the temperature, pressure, selection and ratio of reaction elements, rotation speed, growth rate, V / III ratio, and combination of doping elements, sequentially growing a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, an upper confinement layer, and a p-type contact layer on the single crystal substrate to prepare a gallium nitride-based semiconductor laser;

[0014] The temperature change of the p-type contact layer has y=A x Curve distribution, where A>1, makes the peak rate electric field of the p-type contact layer have the function y=sinx / x 2 The first quadrant curve distribution, x is the depth from the p-type contact layer to the upper confinement layer;

[0015] Or, the pressure change of the p-type contact layer has y=B x Curve distribution, where B>1, makes the transverse acoustic velocity of the p-type contact layer have the function y=sinx / x 2 The first quadrant curve distribution;

[0016] Or, the rotation speed change of the p-type contact layer has y=C x Curve distribution, wherein 0<C<1, so that the saturated electron drift velocity of the p-type contact layer has a first four-quadrant curve distribution of function y=cosx / x;

[0017] Among them, 0<C<1<B≤A.

[0018] Preferably, the growth temperature of the lower limiting layer and the upper limiting layer is 1000°C to 1200°C, the growth pressure is 100Torr to 300Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 1000 to 1350 rpm, the growth rate is 0.2um / h to 5um / h, the V / III ratio is 100 to 80000, and the doping element is any one of SiH4, disilane or Cp2Mg.

[0019] Preferably, the growth temperature of the lower waveguide layer is 650°C to 1000°C, the growth pressure is 100Torr to 300Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 450 to 750 rpm, the growth rate is 0.05um / h to 2um / h, the V / III ratio is 1000 to 90000, and the doping element is SiH4 or disilane.

[0020] Preferably, the growth temperature of the active layer is 600°C to 950°C, the growth pressure is 150Torr to 750Torr, the reaction elements are TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 300 to 800 rpm, the growth rate is 0.002um / h to 2um / h, the V / III ratio is 1000 to 90000, and the doping element is SiH4 or disilane.

[0021] Preferably, the growth temperature of the upper waveguide layer is 650°C to 1000°C, the growth pressure is 100Torr to 300Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 400 to 900 rpm, the growth rate is 0.05um / h to 2um / h, the V / III ratio is 1000 to 90000, and the doping element is any one of SiH4, disilane or Cp2Mg.

[0022] Preferably, the growth temperature of the electron blocking layer is 850°C to 1200°C, the growth pressure is 100Torr to 250Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 800 to 1300 rpm, the growth rate is 0.05um / h to 3um / h, the V / III ratio is 100 to 90000, and the doping element is any one of SiH4, disilane or Cp2Mg.

[0023] A second aspect of an embodiment of the present invention provides a gallium nitride-based semiconductor laser, comprising a single crystal substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper confinement layer arranged in sequence from bottom to top, a p-type contact layer being arranged above the upper confinement layer, and the p-type contact layer having peak rate electric field distribution characteristics, transverse sound velocity distribution characteristics and saturated electron drift velocity distribution characteristics.

[0024] Preferably, the peak rate electric field of the p-type contact layer has a function y=sinx / x 2 The first quadrant curve distribution, x is the depth from the p-type contact layer to the upper confinement layer.

[0025] Preferably, the transverse acoustic velocity of the p-type contact layer has a function y=sinx / x 2 The first quadrant curve distribution, x is the depth from the p-type contact layer to the upper confinement layer.

[0026] Preferably, the saturated electron drift velocity of the p-type contact layer has a first four-quadrant curve distribution of the function y=cosx / x, where x is the depth of the p-type contact layer in a direction toward the upper confinement layer.

[0027] Preferably, the p-type contact layer also has an In / O element ratio distribution characteristic, and the In / O element ratio of the p-type contact layer has a function y=(e x +e -x ) / (e x -e -x ) The first quadrant curve distribution, x is the depth of the p-type contact layer toward the upper confinement layer.

[0028] Preferably, the p-type contact layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, SiC, Ga2O3, BN, and diamond.

[0029] Preferably, the active layer is a periodic structure composed of a well layer and a barrier layer, and the number of periods is 3≥m≥1;

[0030] The well layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond, and has a thickness of 10 angstroms to 100 angstroms;

[0031] The barrier layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond, with a thickness of 10 to 150 angstroms.

[0032] Preferably, the lower limiting layer, the lower waveguide layer, the electron blocking layer, the upper waveguide layer and the upper limiting layer are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN and diamond.

[0033] Preferably, the single crystal substrate includes any one of sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite single crystal substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite single crystal substrate, diamond, sapphire / SiNx, sapphire / SiO2 / SiNx composite single crystal substrate, magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite single crystal substrate.

[0034] The beneficial effects of the present invention are as follows: the present invention provides a p-type contact layer above the upper confinement layer of the gallium nitride-based semiconductor laser, and the p-type contact layer has peak rate electric field distribution characteristics, transverse sound velocity distribution characteristics and saturated electron drift rate distribution characteristics, which can improve hole mobility and hole transport efficiency, thereby improving the hole expansion capacity of the p-type contact layer, thereby improving the ESD of the laser and reducing the voltage. At the same time, the Joule heat loss generated by the p-type contact layer of the laser is reduced, the heat accumulation and temperature rise of the laser are reduced, the thermal red shift of the laser is improved, and the life and reliability of the laser are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0036] Figure 1 This is a schematic structural diagram of the gallium nitride-based semiconductor laser according to Embodiment 2 of the present invention;

[0037] Figure 2 This is a SIMS secondary ion mass spectrum of the gallium nitride-based semiconductor laser described in Example 2 of the present invention;

[0038] Figure 3 This is a partially enlarged SIMS secondary ion mass spectrum of the gallium nitride-based semiconductor laser described in Example 2 of the present invention.

[0039] Reference numerals:

[0040] 100. Single crystal substrate, 101. Lower confinement layer, 102. Lower waveguide layer, 103. Active layer, 104. Upper waveguide layer, 105. Electron blocking layer, 106. Upper confinement layer, 107. P-type contact layer. DETAILED DESCRIPTION

[0041] In order to make the technical solutions and advantages in the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0042] Example 1

[0043] This embodiment provides a method for preparing a gallium nitride-based semiconductor laser. The gallium nitride-based semiconductor laser can be prepared by the preparation method. The preparation method includes:

[0044] A single crystal substrate is used as a substrate;

[0045] Placing the single crystal substrate in a MOCVD reaction chamber;

[0046] The temperature, pressure, selection and proportion of reaction elements, rotation speed, growth rate, V / III ratio, and combination of doping elements are regulated to sequentially grow a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, an upper confinement layer, and a p-type contact layer on the single crystal substrate to prepare a gallium nitride-based semiconductor laser.

[0047] Specifically, in this embodiment, firstly, a suitable single crystal substrate material is selected as the substrate, and the substrate is cleaned by KOH or an acidic solution to remove the contaminants on the surface of the substrate. Then the single crystal substrate is placed on a graphite disk and transferred into the MOCVD (metal organic chemical vapor deposition) reaction chamber, and the reaction chamber is evacuated. The single crystal substrate is preheated and heated, and the appropriate pressure, rotation speed, temperature and other conditions are adjusted, and any one or any combination of N2, H2, NH3, SiH4, and Cp2Mg for single crystal surface treatment is introduced. The set temperature, pressure, reaction element selection and ratio, rotation speed, growth rate, V / III ratio, and combination of doping elements are adjusted to grow the lower confinement layer on the single crystal substrate. The set temperature, pressure, reaction element selection and ratio, rotation speed, growth rate, V / III ratio, and combination of doping elements are adjusted to grow the lower waveguide layer, active layer, and upper waveguide layer on the lower confinement layer in sequence. The set temperature, pressure, reaction element selection and ratio, rotation speed, growth rate, V / III ratio, and combination of doping elements are adjusted to grow an electron blocking layer above the upper waveguide layer. The set temperature, pressure, reaction element selection and ratio, rotation speed, growth rate, V / III ratio, and combination of doping elements are adjusted to use MOCVD to epitaxially grow an upper confinement layer above the electron blocking layer. The set temperature, pressure, reaction element selection and ratio, rotation speed, growth rate, V / III ratio, and combination of doping elements are adjusted to use MOCVD to epitaxially grow a p-type contact layer above the upper confinement layer. After the growth is completed, the temperature of the reaction chamber is gradually lowered, H2 is turned off, and any one or any combination of N2 and NH3 is maintained to cool the grown single crystal material and avoid being corroded by H2. The single crystal substrate is taken out of the reaction chamber and processed by the laser chip process to prepare a gallium nitride-based semiconductor laser.

[0048] In this embodiment, the temperature, pressure and rotation speed of the p-type contact may have certain distribution changes, and the distribution changes of the temperature, pressure and rotation speed may exist alone or in combination.

[0049] Specifically, the temperature change of the p-type contact layer has y=A x Curve distribution, where A>1, makes the peak rate electric field of the p-type contact layer have the function y=sinx / x 2 The first quadrant curve distribution, x is the depth of the p-type contact layer in the direction of the upper limiting layer. By adjusting the peak rate electric field of the p-type contact layer, the hole transport efficiency and mobility are improved, and the voltage and resistance of the laser are reduced.

[0050] The pressure change of the p-type contact layer has y=B x Curve distribution, where B>1, makes the transverse acoustic velocity of the p-type contact layer have the function y=sinx / x 2The first quadrant curve distribution. By regulating the transverse sound velocity of the p-type contact layer, improving phonon transport, reducing the Joule heat loss of the p-type contact layer, reducing the heat accumulation and temperature rise of the laser, improving the thermal red shift of the laser, and improving the life and reliability of the laser.

[0051] The rotation speed change of the p-type contact layer has y=C x The curve distribution, wherein 0<C<1, makes the saturated electron drift rate of the p-type contact layer have the first four-quadrant curve distribution of the function y=cosx / x, wherein 0<C<1<B≤A. By regulating the saturated electron drift rate of the p-type contact layer, the hole expansion capability is improved, the carrier congestion problem is suppressed, and the ESD capability of the laser is improved and the voltage is reduced.

[0052] In some optional embodiments, the growth temperature of the lower limit layer and the upper limit layer is 1000°C to 1200°C, the growth pressure is 100Torr to 300Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 1000 to 1350 rpm, the growth rate is 0.2um / h to 5um / h, the V / III ratio is 100 to 80000, and the doping element is any one of SiH4, disilane or Cp2Mg.

[0053] In some optional embodiments, the growth temperature of the lower waveguide layer is 650°C to 1000°C, the growth pressure is 100Torr to 300Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 450 to 750 rpm, the growth rate is 0.05um / h to 2um / h, the V / III ratio is 1000 to 90000, and the doping element is SiH4 or disilane.

[0054] In some optional embodiments, the growth temperature of the active layer is 600°C to 950°C, the growth pressure is 150Torr to 750Torr, the reaction elements are TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 300 to 800 rpm, the growth rate is 0.002um / h to 2um / h, the V / III ratio is 1000 to 90000, and the doping element is SiH4 or disilane.

[0055] In some optional embodiments, the growth temperature of the upper waveguide layer is 650°C to 1000°C, the growth pressure is 100Torr to 300Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 400 to 900 rpm, the growth rate is 0.05um / h to 2um / h, the V / III ratio is 1000 to 90000, and the doping element is any one of SiH4, disilane or Cp2Mg.

[0056] In some optional embodiments, the growth temperature of the electron blocking layer is 850°C to 1200°C, the growth pressure is 100Torr to 250Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 800 to 1300 rpm, the growth rate is 0.05um / h to 3um / h, the V / III ratio is 100 to 90000, and the doping element is any one of SiH4, disilane or Cp2Mg.

[0057] Example 2

[0058] like Figures 1 to 3 As shown, this embodiment provides a gallium nitride-based semiconductor laser, comprising a single crystal substrate 100, a lower confinement layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, an electron blocking layer 105 and an upper confinement layer 106, which are arranged in sequence from bottom to top, wherein a p-type contact layer 107 is arranged above the upper confinement layer 106.

[0059] Specifically, Figure 1 As shown, in this embodiment, the gallium nitride-based semiconductor laser is provided with a single crystal substrate 100, a lower confinement layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, an electron blocking layer 105 and an upper confinement layer 106 in sequence from bottom to top. A p-type contact layer 107 is provided above the upper confinement layer 106. The p-type contact layer 107 can be any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, SiC, Ga2O3, BN, and diamond.

[0060] In this embodiment, the p-type contact layer 107 has some parameter distribution characteristics, including peak velocity electric field distribution characteristics, transverse acoustic velocity distribution characteristics, and saturated electron drift velocity distribution characteristics.

[0061] The peak rate electric field is the peak intensity of the rate electric field, and the peak rate electric field is a basic property of the crystal.

[0062] The speed of sound describes the distance that a sound wave travels per unit time in an elastic medium. It is a very important basic parameter in acoustic research and a powerful means to study the elastic mechanical properties of materials.

[0063] Saturated electron drift rate, when the electric field is relatively low, the overall electron drift speed is proportional to the electric field size. When the electric field reaches a certain value, the overall electron drift speed will no longer increase and reach saturation. This speed is called the saturated electron drift rate. The saturated electron drift rate determines the upper limit of the electron drift rate.

[0064] Based on the above characteristics of the peak rate electric field, transverse acoustic velocity and saturated electron drift velocity, this embodiment further designs the peak rate electric field distribution, transverse acoustic velocity distribution and saturated electron drift velocity distribution of the p-type contact layer 107, such as Figure 2 and Figure 3 As shown, the details are as follows:

[0065] (1) Peak rate electric field distribution

[0066] The peak rate electric field of the p-type contact layer 107 has a function y=sinx / x 2 The first quadrant curve distribution;

[0067] (2) Transverse sound velocity distribution

[0068] The transverse acoustic velocity of the p-type contact layer 107 has a function y=sinx / x 2 The first quadrant curve distribution;

[0069] (3) Saturated electron drift velocity distribution

[0070] The saturated electron drift velocity of the p-type contact layer 107 has a first four-quadrant curve distribution of the function y=cosx / x;

[0071] Here, x is the depth of the p-type contact layer 107 in the direction of the upper confinement layer 106 .

[0072] In this embodiment, a p-type contact layer 107 is provided above the upper confinement layer 106 of the gallium nitride-based semiconductor laser, and the p-type contact layer 107 has peak rate electric field distribution characteristics, transverse sound velocity distribution characteristics, and saturated electron drift velocity distribution characteristics, which can improve hole mobility and hole transport efficiency, thereby improving the hole expansion capability of the p-type contact layer 107, thereby improving the ESD of the laser and reducing the voltage. At the same time, the Joule heat loss generated by the p-type contact layer 107 of the laser is reduced, the heat accumulation and temperature rise of the laser are reduced, the thermal red shift of the laser is improved, and the life and reliability of the laser are improved.

[0073] Furthermore, in this embodiment, the p-type contact layer 107 has, in addition to the above-mentioned peak rate electric field distribution characteristics, transverse acoustic velocity distribution characteristics and saturated electron drift velocity distribution characteristics, an In / O element ratio distribution characteristic, which is specifically manifested as follows: the In / O element ratio of the p-type contact layer 107 has a function y=(e x +e -x ) / (e x -e -x )The first quadrant curve distribution.

[0074] In this embodiment, the In / O element ratio distribution characteristics are designed in the p-type contact layer 107 , which can further improve the hole mobility and the hole transport efficiency, thereby improving the hole expansion capability of the p-type contact layer 107 .

[0075] In addition, in this embodiment, the active layer 103 is a periodic structure composed of a well layer and a barrier layer, and the number of periods is 3≥m≥1.

[0076] Among them, the well layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond, and the thickness is 10 angstroms to 100 angstroms.

[0077] The barrier layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond, with a thickness of 10 to 150 angstroms.

[0078] The lower confinement layer 101, the lower waveguide layer 102, the upper waveguide layer 104, the electron blocking layer 105 and the upper confinement layer 106 are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond.

[0079] The single crystal substrate 100 includes any one of sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite single crystal substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite single crystal substrate, diamond, sapphire / SiNx, sapphire / SiO2 / SiNx composite single crystal substrate, magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite single crystal substrate.

[0080] The following table is a parameter comparison between a conventional semiconductor laser and the gallium nitride-based semiconductor laser proposed in this embodiment, including HBM 100KV ESD pass rate, HBM 200KV ESD pass rate, voltage, 1000H aging light attenuation, and temperature quenching ratio, showing the difference between the conventional semiconductor laser and the gallium nitride-based semiconductor laser proposed in this embodiment:

[0081]

[0082] The gallium nitride-based semiconductor laser of this embodiment is tested using a laser chip test device, wherein the gallium nitride-based semiconductor laser is designed with a ridge width of 45um, a cavity length of 1200um, a test current of 0~4A ampere pulse or continuous mode test, and a test environment temperature of 25°C. Then, the laser optical power signal is collected by an integrating sphere to test the optical power and voltage; an ESD test system is used to test the ESD of the HBM human body model;

[0083] When conducting the aging life test, the sample is placed in an oven for aging test, where the aging temperature is 65°C and the aging current is 3A. Then the optical power attenuation at different aging times is tested, and the proportion of dead lamps quenched by temperature is counted.

[0084] It can be seen that the gallium nitride-based semiconductor laser proposed in this embodiment improves the HBM 100KV ESD pass rate and the HBM 200KV ESD pass rate compared with the traditional semiconductor laser, reduces the voltage, 1000H aging light attenuation and temperature quenching ratio, and has obvious advantages over the traditional semiconductor laser.

[0085] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for preparing a gallium nitride-based semiconductor laser, characterized in that: The preparation method comprises: A single crystal substrate is used as a substrate; Placing the single crystal substrate in a MOCVD reaction chamber; Regulating the temperature, pressure, selection and ratio of reaction elements, rotation speed, growth rate, V / III ratio, and combination of doping elements, sequentially growing a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, an upper confinement layer, and a p-type contact layer on the single crystal substrate to prepare a gallium nitride-based semiconductor laser; The temperature change of the p-type contact layer has y=A x (A>1) curve distribution, so that the peak rate electric field of the p-type contact layer has the function y=sinx / x 2 The first quadrant curve distribution, x is the depth from the p-type contact layer to the upper confinement layer; Or, the pressure change of the p-type contact layer has y=B x (B>1) curve distribution, so that the transverse acoustic velocity of the p-type contact layer has the function y=sinx / x 2 The first quadrant curve distribution; Or, the rotation speed change of the p-type contact layer has y=C x (0<C<1) curve distribution, so that the saturated electron drift velocity of the p-type contact layer has a first four-quadrant curve distribution of function y=cosx / x; Among them, 0<C<1<B≤A.

2. The method for preparing a gallium nitride-based semiconductor laser according to claim 1, characterized in that: The growth temperature of the lower limiting layer and the upper limiting layer is 1000° C. to 1200° C., the growth pressure is 100 Torr to 300 Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 1000 to 1350 rpm, the growth rate is 0.2um / h to 5um / h, the V / III ratio is 100 to 80000, and the doping element is any one of SiH4, disilane or Cp2Mg; The growth temperature of the lower waveguide layer is 650° C. to 1000° C., the growth pressure is 100 Torr to 300 Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 450 to 750 rpm, the growth rate is 0.05 um / h to 2 um / h, the V / III ratio is 1000 to 90000, and the doping element is SiH4 or disilane; The growth temperature of the active layer is 600° C. to 950° C., the growth pressure is 150 Torr to 750 Torr, the reaction elements are TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 300 to 800 rpm, the growth rate is 0.002 um / h to 2 um / h, the V / III ratio is 1000 to 90000, and the doping element is SiH4 or disilane; The growth temperature of the upper waveguide layer is 650° C. to 1000° C., the growth pressure is 100 Torr to 300 Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 400 to 900 rpm, the growth rate is 0.05 um / h to 2 um / h, the V / III ratio is 1000 to 90000, and the doping element is any one of SiH4, disilane or Cp2Mg; The growth temperature of the electron blocking layer is 850°C to 1200°C, the growth pressure is 100Torr to 250Torr, the reaction elements are TMGa, TEGa, TMAl, TMIn, NH3, N2, H2, the rotation speed is 800 to 1300 rpm, the growth rate is 0.05um / h to 3um / h, the V / III ratio is 100 to 90000, and the doping element is any one of SiH4, disilane or Cp2Mg.

3. A gallium nitride-based semiconductor laser, comprising a single crystal substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper confinement layer arranged in sequence from bottom to top, characterized in that: A p-type contact layer is disposed above the upper confinement layer, and the p-type contact layer has peak rate electric field distribution characteristics, transverse sound velocity distribution characteristics, and saturated electron drift velocity distribution characteristics; The peak rate electric field of the p-type contact layer has a function y=sinx / x 2 The first quadrant curve distribution; The transverse acoustic velocity of the p-type contact layer has a function y=sinx / x 2 The first quadrant curve distribution; The saturated electron drift velocity of the p-type contact layer has a first four-quadrant curve distribution of function y=cosx / x; Wherein, x is the depth of the p-type contact layer toward the upper confinement layer.

4. The gallium nitride-based semiconductor laser according to claim 3, characterized in that: The p-type contact layer also has an In / O element ratio distribution characteristic, and the In / O element ratio of the p-type contact layer has a function y=(e x +e -x ) / (e x -e -x ) The first quadrant curve distribution, x is the depth of the p-type contact layer toward the upper confinement layer.

5. The gallium nitride-based semiconductor laser according to claim 3, characterized in that: The p-type contact layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, SiC, Ga2O3, BN, and diamond.

6. The gallium nitride-based semiconductor laser according to claim 3, characterized in that: The active layer is a periodic structure composed of a well layer and a barrier layer, and the number of periods is 3≥m≥1; The well layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond, and has a thickness of 10 angstroms to 100 angstroms; The barrier layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond, with a thickness of 10 to 150 angstroms.

7. The gallium nitride-based semiconductor laser according to claim 3, characterized in that: The lower confinement layer, the lower waveguide layer, the electron blocking layer, the upper waveguide layer, and the upper confinement layer are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond; The single crystal substrate includes any one of sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite single crystal substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite single crystal substrate, diamond, sapphire / SiNx, sapphire / SiO2 / SiNx composite single crystal substrate, magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite single crystal substrate.

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