A semiconductor laser

Abstract

This invention discloses a semiconductor laser, comprising, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer. An orbital hybrid layer is located between the upper waveguide layer and the upper confinement layer, comprising a first orbital hybrid layer, a second orbital hybrid layer, and a third orbital hybrid layer. The specific covalent bond energy distribution and dielectric constant distribution of the orbital hybrid layer in this invention enhance band hybridization, enhance Pz orbital hybridization in the vertical direction and real-space overlap, regulate interface conductivity and dual band reversal, enhance electron and hole transport paths along the basal plane, enhance hole ionization rate and hole carrier concentration, improve hole expansion capability, increase epitaxial structure capacitance, and enhance HBM human body mode ESD of the laser.

Description

Technical Field

[0001] This invention relates to the field of semiconductor optoelectronic device technology, and more particularly to a semiconductor laser. Background Technology

[0002] Lasers are widely used in laser displays, laser TVs, laser projectors, communications, medical applications, weaponry, guidance, ranging, spectral analysis, cutting, precision welding, and high-density optical storage. There are many types of lasers, and they can be classified in various ways, mainly including solid-state, gas, liquid, semiconductor, and dye lasers. Compared with other types of lasers, all-solid-state semiconductor lasers have advantages such as small size, high efficiency, light weight, good stability, long lifespan, simple and compact structure, and miniaturization.

[0003] There are significant differences between lasers and nitride semiconductor light-emitting diodes (LEDs): 1) Lasers are generated by stimulated emission of charge carriers, have a small full width at half maximum (FW), and very high brightness; a single laser can have an output power in the W range. In contrast, nitride semiconductor LEDs emit spontaneous radiation, and a single LED has an output power in the mW range; 2) Lasers can operate at current densities of up to kA / cm². 2 The efficiency of LEDs is more than two orders of magnitude higher than that of nitride LEDs, resulting in stronger electron leakage, more severe Auger recombination, stronger polarization effect, and more severe electron-hole mismatch, leading to more severe efficiency degradation and the Droop effect; 3) LEDs emit spontaneous transition radiation without external influence, producing incoherent light from high energy levels to low energy levels, while lasers emit stimulated transition radiation, where the energy of the induced photon must be equal to the energy difference of the electron transition, producing coherent light between the photon and the induced photon; 4) The principles are different: LEDs emit radiative recombination light under the action of external voltage, where electrons and holes transition to quantum wells or pn junctions, while lasers require lasing conditions to be met, which must satisfy the inversion distribution of charge carriers in the active region. The stimulated emission light oscillates back and forth in the resonant cavity, and the propagation in the gain medium amplifies the light, satisfying the threshold condition so that the gain is greater than the loss, and finally outputting laser light.

[0004] Nitride semiconductor lasers have the following problems: 1) High internal defect density, imperfect crystal quality, low capacitance, poor current spread, and low capacitance in the epitaxial structure, resulting in ESD deviation in HBM human body mode; 2) The Mg acceptor activation energy of p-type semiconductors is large and the ionization efficiency is low. The hole concentration is much lower than the electron concentration and the hole mobility is much lower than the electron mobility, resulting in a severe asymmetric mismatch between electrons and holes in the quantum well, leading to electron leakage and low hole injection efficiency. Summary of the Invention

[0005] This invention proposes a semiconductor laser in which the specific covalent bond energy distribution and dielectric constant distribution of the orbital hybrid layer enhance band hybridization, enhance Pz orbital hybridization in the vertical direction and overlap in real space, regulate interface conductivity and dual band reversal, enhance electron and hole transport paths along the basal plane, enhance hole ionization rate and hole carrier concentration, improve hole expansion capability, improve epitaxial structure capacitance, and enhance HBM human body mode ESD of the laser.

[0006] The present invention provides a semiconductor laser, comprising, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer, wherein an orbital hybridization layer is provided between the upper waveguide layer and the upper confinement layer.

[0007] The orbital hybrid 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.

[0008] The orbital hybrid layer includes a first orbital hybrid layer, a second orbital hybrid layer, and a third orbital hybrid layer.

[0009] Preferably, the covalent bond energy distribution of the first orbital hybrid layer has a first quadrant curve distribution of the function y = A + B*x / lnx, and the covalent bond energy distribution of the second orbital hybrid layer has a logarithmic function y = C + D*log a The x(0<a<1) curve distribution and the covalent bond energy distribution of the third orbital hybrid layer have a fourth quadrant curve distribution of the function y=E+F*x / lnx;

[0010] Preferably, the covalent bond energy of the first orbital hybrid layer is d, the covalent bond energy of the second orbital hybrid layer is e, and the covalent bond energy of the third orbital hybrid layer is f, where: 0.5≤d≤e≤f≤5 (eV).

[0011] Preferably, the dielectric constant distribution of the first orbital hybrid layer has a function y = G + H * lnx / x curve distribution, and the dielectric constant distribution of the second orbital hybrid layer has a logarithmic function y = I + J * log b1 The distribution of the x(b1>1) curve and the dielectric constant distribution of the third orbital hybrid layer have the function y=K+L*sinx / x 2 The distribution of curves in the third quadrant.

[0012] Preferably, the dielectric constant of the first orbital hybrid layer is g, the dielectric constant of the second orbital hybrid layer is h, and the dielectric constant of the third orbital hybrid layer is i, where: 5≤i≤h≤g≤15.

[0013] Preferably, the valence band effective state density distribution of the first orbital hybrid layer has the function y = M + N * lnx / e x The curve distribution of the effective state density distribution of the valence band in the second orbital hybrid layer has a logarithmic function y = O + P * log b2 The x(b2>1) curve distribution and the effective state density distribution of the valence band of the third orbital hybrid layer have the function y=Q+R*xe x Curve distribution; the effective valence band state density of the first orbital hybrid layer is j, the effective valence band state density of the second orbital hybrid layer is k, and the effective valence band state density of the third orbital hybrid layer is l, where: 1E18≤l≤k≤j≤9E20 (cm / s).

[0014] Preferably, the effective state density distribution of the conduction band of the first orbital hybrid layer has the function y = S + T * sinx / x 2 The distribution of curves in the first quadrant and the effective density of states in the conduction band of the second orbital hybrid layer exhibit a logarithmic function y = U + V * log b3 The x(b3>1) curve distribution and the effective density of states distribution of the conduction band of the third orbital hybrid layer have the function y=W+Z*e. x / x 2 The second quadrant curve distribution; the effective density of states in the conduction band of the first orbital hybrid layer is m, the effective density of states in the conduction band of the second orbital hybrid layer is n, and the effective density of states in the conduction band of the third orbital hybrid layer is p, where: 1E16≤m≤p≤n≤1E19 (cm / s).

[0015] Preferably, the active layer is a periodic structure composed of a well layer and a barrier layer, with a period number of 3 ≥ m ≥ 1. The well layer is any one 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. Any combination, with a thickness of 10~100 angstroms, and the barrier layer being 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 10~200 angstroms.

[0016] Preferably, the lower confinement layer, lower waveguide layer, upper waveguide layer, and 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.

[0017] Preferably, the substrate comprises sapphire, silicon, Ge, SiC, Mo, CuW, TiW, Cu, diamond, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiNx, sapphire / SiO2 / SiN x The composite substrate, or any one of the following: magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2, and LiGaO2 composite substrate.

[0018] Compared with the prior art, the semiconductor laser provided in this embodiment of the invention has the following advantages:

[0019] The specific covalent bond energy distribution and dielectric constant distribution of the orbital hybrid layer enhance band hybridization, enhance the hybridization of Pz orbitals in the vertical direction and the overlap in real space, regulate the interface conductivity and dual band reversal, enhance the electron and hole transport paths along the basal plane, enhance the hole ionization rate and hole carrier concentration, improve the hole expansion capability, improve the capacitance value of the epitaxial structure, and enhance the ESD of the laser's HBM human body mode.

[0020] The specific effective state density distribution of the valence band and the specific effective state density distribution of the conduction band in the orbital hybrid layer improves the conductivity and charge transfer of the laser interface, enhances the matching degree of electrons and holes in the quantum well, reduces contact resistance, voltage and threshold current density, and improves the lateral and longitudinal current spread, thereby improving ESD performance. This can increase the ESD pass rate of the laser in HBM human body mode from over 50% to 98% at 100V and from 15% to over 93% at 200V. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a semiconductor laser provided by the present invention.

[0022] Figure 2 The present invention provides a SIMS secondary ion mass spectrum of a semiconductor laser.

[0023] The diagram shows: 100: substrate; 101: lower confinement layer; 102: lower waveguide layer; 103: active layer; 104: upper waveguide layer; 105: upper confinement layer; 106: orbital hybrid layer; 106a: first orbital hybrid layer; 106b: second orbital hybrid layer; 106c: third orbital hybrid layer. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] To address the aforementioned issues, a semiconductor laser provided in this application will be described in detail and explained through the following specific embodiments.

[0026] Reference Figure 1-2The present invention provides a semiconductor laser, comprising, from bottom to top, a substrate 100, a lower confinement layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, and an upper confinement layer 105, wherein an orbital hybridization layer 106 is provided between the upper waveguide layer 104 and the upper confinement layer 105.

[0027] The orbital hybrid layer 106 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.

[0028] The orbital hybrid layer 106 includes a first orbital hybrid layer 106a, a second orbital hybrid layer 106b, and a third orbital hybrid layer 106c.

[0029] The covalent bond energy distribution of the first orbital hybrid layer 106a has a first quadrant curve distribution of the function y = A + B*x / lnx, and the covalent bond energy distribution of the second orbital hybrid layer 106b has a logarithmic function y = C + D*log a The covalent bond energy distribution of the third orbital hybrid layer 106c follows a curve distribution of x (0 < a < 1), and the covalent bond energy distribution follows a curve distribution in the fourth quadrant of the function y = E + F*x / lnx. The covalent bond energy of the first orbital hybrid layer 106a is d, the covalent bond energy of the second orbital hybrid layer 106b is e, and the covalent bond energy of the third orbital hybrid layer 106c is f, where 0.5 ≤ d ≤ e ≤ f ≤ 5 (eV). The dielectric constant distribution of the first orbital hybrid layer 106a follows a curve distribution of the function y = G + H*lnx / x, and the dielectric constant distribution of the second orbital hybrid layer 106b follows a logarithmic function y = I + J*log b1 The distribution of the x(b1>1) curve, and the dielectric constant distribution of the third orbital hybrid layer 106c, have the function y=K+L*sinx / x. 2 The curve distribution is in the third quadrant. The dielectric constant of the first orbital hybrid layer 106a is g, the dielectric constant of the second orbital hybrid layer 106b is h, and the dielectric constant of the third orbital hybrid layer 106c is i, where: 5≤i≤h≤g≤15.

[0030] In summary, the specific covalent bond energy distribution and dielectric constant distribution of the orbital hybrid layer enhance band hybridization, enhance the hybridization of Pz orbitals in the vertical direction and the overlap in real space, regulate interface conductivity and dual band reversal, enhance electron and hole transport paths along the basal plane, enhance hole ionization rate and hole carrier concentration, improve hole expansion capability, increase epitaxial structure capacitance, and enhance ESD in the human body mode (HBM) of the laser.

[0031] The effective state density distribution of the valence band of the first orbital hybrid layer 106a has the function y = M + N * lnx / e x The effective state density distribution of the valence band in the second orbital hybrid layer 106b exhibits a logarithmic function y = O + P * log b2 The x(b2>1) curve distribution shows that the effective state density distribution of the valence band in the third orbital hybrid layer 106c has the function y=Q+R*xe. x The effective valence band state density of the first orbital hybrid layer 106a is j, that of the second orbital hybrid layer 106b is k, and that of the third orbital hybrid layer 106c is l, where: 1E18≤l≤k≤j≤9E20 (cm / s). The effective conduction band state density distribution of the first orbital hybrid layer 106a has the function y=S+T*sinx / x. 2 The distribution of curves in the first quadrant and the effective density of states in the conduction band of the second orbital hybrid layer 106b exhibit a logarithmic function y = U + V * log b3 The x(b3>1) curve distribution shows that the effective density of states in the conduction band of the third orbital hybrid layer 106c has the function y=W+Z*e. x / x 2 The curve distribution in the second quadrant; the effective density of states in the conduction band of the first orbital hybrid layer 106a is m, the effective density of states in the conduction band of the second orbital hybrid layer 106b is n, and the effective density of states in the conduction band of the third orbital hybrid layer 106c is p, where: 1E16≤m≤p≤n≤1E19 (cm / s).

[0032] In summary, specific effective state density distributions in the valence band and conduction band of the orbital hybrid layer improve the conductivity and charge transfer at the laser interface, enhance the electron-hole matching degree in the quantum well, reduce contact resistance, voltage, and threshold current density, and improve the lateral and longitudinal current spread, thereby improving ESD performance. This can increase the ESD throughput of the laser in HBM human body mode from over 50% at 100V to 98%; and from 15% at 200V to over 93%.

[0033] The table below shows a comparison of data between a conventional laser and the laser of this invention.

[0034] Blue laser - Project Traditional lasers Laser of the present invention range of change <![CDATA[Threshold current density (kA / cm 2 )]]> 2.4 0.74 -69% Voltage (V) 6.5 4.29 -23% Series resistance (Ω) 17 6.3 -59% HBM 100KV ESD pass rate 50% 98% 96% HBM 200KV ESD pass rate 15% 93% 520%

[0035] In this invention, the active layer 103 is a periodic structure composed of a well layer and a barrier layer, with a period number of 3 ≥ m ≥ 1. The well layer is any one 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 material can be of any type or combination thereof, with a thickness of 10 to 100 angstroms. The barrier layer can be 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 200 angstroms.

[0036] In this invention, the lower confinement layer 101, the lower waveguide layer 102, the upper waveguide layer 104, and the upper confinement layer 105 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.

[0037] In this invention, the substrate 100 includes sapphire, silicon, Ge, SiC, Mo, CuW, TiW, Cu, diamond, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiNx, and sapphire / SiO2 / SiN. x The composite substrate, or any one of the following: magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2, and LiGaO2 composite substrate.

[0038] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A semiconductor laser, comprising, from bottom to top, a substrate (100), a lower confinement layer (101), a lower waveguide layer (102), an active layer (103), an upper waveguide layer (104), and an upper confinement layer (105), characterized in that, There is an orbital hybrid layer (106) between the upper waveguide layer (104) and the upper confinement layer (105), and the orbital hybrid layer (106) includes a first orbital hybrid layer (106a), a second orbital hybrid layer (106b) and a third orbital hybrid layer (106c) from bottom to top. The covalent bond energy distribution of the first orbital hybrid layer (106a) has a first quadrant curve distribution of the function y1=A+B*x / lnx, and the covalent bond energy distribution of the second orbital hybrid layer (106b) has a logarithmic function y2=C+D*log a x, 0 < a < 1, curve distribution, the covalent bond energy distribution of the third orbital hybrid layer (106c) has a fourth quadrant curve distribution of the function y3 = E + F*x / lnx; The dielectric constant distribution of the first orbital hybrid layer (106a) follows a function y4=G+H*lnx / x, while the dielectric constant distribution of the second orbital hybrid layer (106b) follows a logarithmic function y5=I+J*log b1 x, b1 > 1, curve distribution, the dielectric constant distribution of the third orbital hybrid layer (106c) has the function y6 = K + L*sinx / x 2 Third quadrant curve distribution; The valence band effective state density distribution of the first orbital hybrid layer (106a) has the function y7=M+N*lnx / e x The curve distribution of the effective density of states in the valence band of the second orbital hybrid layer (106b) has a logarithmic function y8=O+P*log b2 x, b2 > 1, curve distribution, the valence band effective state density distribution of the third orbital hybrid layer (106c) has the function y9 = Q + R*xe x Curve distribution; The effective state density distribution of the conduction band of the first orbital hybrid layer (106a) has a function y 10 =S+T*sinx / x 2 The distribution of curves in the first quadrant and the effective density of states in the conduction band of the second orbital hybrid layer (106b) exhibit a logarithmic function y. 11 =U+V*log b3 The curve distribution of x, b3>1, and the effective state density distribution of the conduction band of the third orbital hybrid layer (106c) have a function y 12 =W+Z*e x / x 2 The second quadrant curve distribution.

2. A semiconductor laser according to claim 1, characterized in that, The covalent bond energy of the first orbital hybrid layer (106a) is d, the covalent bond energy of the second orbital hybrid layer (106b) is e, and the covalent bond energy of the third orbital hybrid layer (106c) is f, where 0.5≤d≤e≤f≤5, and the unit is eV.

3. A semiconductor laser according to claim 1, characterized in that, The dielectric constant of the first orbital hybrid layer (106a) is g, the dielectric constant of the second orbital hybrid layer (106b) is h, and the dielectric constant of the third orbital hybrid layer (106c) is i, where: 5≤i≤h≤g≤15.

4. A semiconductor laser according to claim 1, characterized in that, The effective valence band density of states of the first orbital hybrid layer (106a) is j, the effective valence band density of states of the second orbital hybrid layer (106b) is k, and the effective valence band density of states of the third orbital hybrid layer (106c) is l, where: 1E18≤l≤k≤j≤9E20, and the unit is cm / s.

5. A semiconductor laser according to claim 1, characterized in that, The effective density of states in the conduction band of the first orbital hybrid layer (106a) is m, the effective density of states in the conduction band of the second orbital hybrid layer (106b) is n, and the effective density of states in the conduction band of the third orbital hybrid layer (106c) is p, where: 1E16≤m≤p≤n≤1E19, and the unit is cm / s.

6. A semiconductor laser according to claim 1, characterized in that, The active layer (103) is a periodic structure composed of a well layer and a barrier layer, with a period number of 3 ≥ m ≥ 1. The well layer is any one 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. Any combination, with a thickness of 10~100 angstroms, and the barrier layer being 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 10~200 angstroms.

7. A semiconductor laser according to claim 1, characterized in that, The lower confinement layer (101), lower waveguide layer (102), upper waveguide layer (104), and upper confinement layer (105) 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.

8. A semiconductor laser according to claim 1, characterized in that, The substrate (100) includes sapphire, silicon, Ge, SiC, Mo, CuW, TiW, Cu, diamond, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiNx composite substrate, and sapphire / SiO2 / SiN composite substrate. x The composite substrate, any one of magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, or LiAlO2 / LiGaO2 composite substrate.

Images