Semiconductor laser chip

Abstract

The utility model relates to the technical field of semiconductor photoelectric devices, in particular to a semiconductor laser chip, which sequentially comprises a substrate, a lower coating layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper coating layer from bottom to top, and is characterized in that the upper coating layer is etched to a position about 5-500nm away from the electron blocking layer through a photoetching process, a laser ridge is etched, and the upper coating layer is etched to a position about 5-500nm away from the electron blocking layer. Preparing a contact electrode above the ridge; the ridge is provided with a first etching interface on the left side and a second etching interface on the right side, and the first etching interface and the second etching interface are distributed in an irregular curve mode or an arc mode or a linear mode. According to the utility model, by controlling the change angle of the ridge and controlling the curve and radian of the bending angle, carrier leakage, light field leakage and stray light are reduced, interference on FFP far-field image quality is reduced, and light beam quality factors are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor optoelectronic devices, in particular to a semiconductor laser chip. 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 ultraviolet lasers have the advantages of small size, high efficiency, light weight, good stability, long life, simple and compact structure, and miniaturization.

[0003] There are significant 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 is up to KA / cm 2 , 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 the active layer or pn junction to produce 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] Nitride semiconductor ultraviolet lasers have the following problems: the interface between the ridge and the coating material above it produces strain due to lattice mismatch, thermal mismatch, and etching angle, which causes the coating material to produce strain, warping, falling off, and breaking, causing laser failure, dead light, and COD optical catastrophe. Utility Model Content

[0009] The utility model proposes a semiconductor laser chip, which controls the change angle of the ridge, controls the curve and radian of the bending angle, reduces carrier leakage, reduces light field leakage and stray light, reduces interference with FFP far-field image quality, and improves the beam quality factor.

[0010] The utility model provides a semiconductor laser chip, which comprises, from bottom to top, a substrate, a lower cladding layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, and an upper cladding layer. Through a photolithography process, the upper cladding layer is etched to a distance of about 5 to 500 nm from the electron blocking layer, a laser ridge is etched, and then a contact electrode is prepared above the ridge; the ridge has a first etching interface on the left and a second etching interface on the right, and the first etching interface and the second etching interface are distributed in an irregular curve, an arc shape, or a linear distribution.

[0011] Preferably, the first etching interface and the second etching interface are distributed in an irregular curve, and the irregular curve distribution bulges toward the center of the ridge; the change angle of the peak position of the irregular curve distribution of the first etching interface of the ridge toward the lower surface of the ridge is α, the change angle of the peak position of the irregular curve distribution of the first etching interface of the ridge toward the upper surface of the ridge is β, the change angle of the peak position of the irregular curve distribution of the second etching interface of the ridge toward the lower surface of the ridge is δ, and the change angle of the peak position of the irregular curve distribution of the second etching interface of the ridge toward the upper surface of the ridge is γ, wherein: 30°≤δ≤α≤γ≤β≤90°.

[0012] Preferably, the first etching interface and the second etching interface are distributed linearly; the width between the first etching interface of the ridge and the lower surface of the ridge is φ, the angle between the first etching interface of the ridge and the upper surface of the ridge is ψ, the width between the second etching interface of the ridge and the lower surface of the ridge is ρ, and the angle between the first etching interface of the ridge and the upper surface of the ridge is θ, wherein: 100°≤θ≤ψ≤ρ≤φ≤180°.

[0013] Preferably, the arc-shaped distribution of the first etching interface and the second etching interface has a hyperbolic function, an elliptical function, a parabolic function, or a conic function distribution.

[0014] Preferably, the linear distribution of the first etching interface has a curve distribution of function y=Ax+B (A>0); the linear distribution of the second etching interface has a curve distribution of function y=Cx+D (C<0), wherein: C<0<A.

[0015] Preferably, the arc distribution of the first etching interface has a second three-quadrant curve distribution of the function y=xE / x (E>0); the arc distribution of the second etching interface has a first four-quadrant curve distribution of the function y=xF / x (F>0).

[0016] Preferably, the arc distribution of the first etching interface has a function y=(G x +1) / (G x -1)(0<G<1) the fourth quadrant curve distribution; the arc distribution of the second etching interface has a function y=(H x +1) / (H x -1)(F>1) is the third quadrant curve distribution.

[0017] Preferably, the arc distribution of the first etching interface has a function y=log a ((M+x) / (Mx))(0<a<1,M>0) The fourth quadrant curve distribution; The arc distribution of the second etching interface has a function y=log b The third quadrant curve distribution of ((N+x) / (Nx))(b>1,N>0).

[0018] Preferably, the arc distribution of the first etching interface has the functions y=l nx / x, y=l nx / e x , y=lnx / x+1 / x-1 any one of the curve distributions in the third quadrant; the arc distribution of the second etching interface has a function y=e x / x、y=si nx / x 2 ,y=(e x +e -x ) / (e x -e -x ) of any curve distribution.

[0019] Preferably, the width of the ridge is 0.5 to 500 microns; the thickness of the ridge is 50 to 50000 nm; the contact electrode is any one or any combination of ITO, Au, Ag, Al, Ti, Pt, Ni, Cr, Zr, Ta, V, Hf, Nb, Pd, Rh, Mo, Cu, NiAu, TiPtAu, TiAlTiAu, CrAlCrPtAu.

[0020] Preferably, the lower cladding layer, the upper waveguide layer, the active layer, the lower waveguide layer, the electron blocking layer, and the upper cladding layer are GaN, InGaN, InN, Al InN, Al GaN, Al InGaN, Al N, GaAs, GaP, InP, Al GaAs, Al InGaAs, Al Ga InP, InGaAs, InGaAsN, Al InAs, Al InP, Al GaP, InGaP, GaSb, InSb, InAs, InAsSb, Al GaSb, Al Sb, InGaSb, Al GaAsSb, InGaAsSb, SiC, Ga2 O 3 , BN, diamond, any one or any combination.

[0021] Preferably, the substrate comprises sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO 2 Composite substrates, Mo, TiW, CuW, Cu, sapphire / AlN composite substrates, diamond, graphene, sapphire / SiN x , Sapphire / SiO 2 / SiN x Composite substrate, sapphire / SiN x / SiO 2 Composite substrate, magnesium aluminum spinel MgAl 2 O 4 、MgO、ZnO、ZrB 2 、LiAlO 2 and LiGaO 2 Any of the composite substrates.

[0022] Compared with the prior art, the semiconductor laser chip provided by the utility model has the following beneficial effects: the utility model controls the changing angle of the ridge, controls the curve and curvature of the bending angle, reduces carrier leakage, reduces light field leakage and stray light, reduces interference with FFP far-field image quality, and improves the beam quality factor; at the same time, controls the etching curve distribution of the ridge, reduces the strain of the first etching interface on the left side of the ridge and the second etching interface on the right side and the coating material above them, reduces the strain warping, shedding and fracture of the coating material, reduces the power density of the cavity surface, reduces the cavity surface load, and improves the reliability of the laser and the dead lamp failure ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of a semiconductor laser chip according to an embodiment of the utility model;

[0024] Figure 2 This is a structural TEM lens electron microscope image of a semiconductor laser chip according to an embodiment of the utility model (the first etching interface and the second etching interface are distributed in irregular curves);

[0025] Figure 3 This is a TEM lens electron microscope image of the structure of a semiconductor laser chip of an embodiment of the utility model (the angle is marked, and the first etching interface and the second etching interface are distributed in irregular curves);

[0026] Figure 4 This is a structural TEM lens electron microscope image of a semiconductor laser chip of an embodiment of the utility model (the first etching interface and the second etching interface are linearly distributed);

[0027] Figure 5 This is a TEM lens electron microscope image of the structure of a semiconductor laser chip of an embodiment of the utility model (the angle is marked, and the first etching interface and the second etching interface are distributed linearly);

[0028] Figure 6 This is a structural TEM lens electron microscope image of a semiconductor laser chip of an embodiment of the utility model (the first etching interface and the second etching interface are distributed in an arc shape);

[0029] Figure 7 This is a structural TEM lens electron microscope image of a semiconductor laser chip in an embodiment of the utility model (the first etching interface and the second etching interface are distributed in an arc shape).

[0030] Figure numerals: 100: substrate; 101: lower cladding layer; 102: lower waveguide layer; 103: active layer; 104: upper waveguide layer, 105: electron blocking layer, 106: upper cladding layer, 107a: upper cladding layer remaining after etching, 107b: ridge, 108: contact electrode, 109: first etching interface, 110: second etching interface. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] In order to solve the above problems, a semiconductor laser chip provided in an embodiment of the present application will be introduced and explained in detail through the following specific embodiments.

[0033] Reference Figure 1-7 The utility model provides a semiconductor laser chip, which includes, from bottom to top, a substrate 100, a lower cladding layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, an electron blocking layer 105, and an upper cladding layer 106. The upper cladding layer 106 is etched to a distance of about 5 to 500 nm from the electron blocking layer 105 by a photolithography process, and a laser ridge 107b is etched. Below the ridge 107 is the upper cladding layer 107a remaining after etching, and then a contact electrode 108 is prepared above the ridge 107b; the ridge 107b has a first etching interface 109 on the left and a second etching interface 110 on the right, and the first etching interface 109 and the second etching interface 110 are distributed in an irregular curve, an arc shape, or a linear shape.

[0034] The first etching interface 109 and the second etching interface 110 are distributed in an irregular curve, and the irregular curve distribution bulges toward the center of the ridge 107b; the change angle of the peak position of the irregular curve distribution bulge of the first etching interface 109 of the ridge toward the lower surface of the ridge 107b is α, the change angle of the peak position of the irregular curve distribution bulge of the first etching interface 109 of the ridge toward the upper surface of the ridge 107b is β, the change angle of the peak position of the irregular curve distribution bulge of the second etching interface 110 of the ridge toward the lower surface of the ridge 107b is δ, and the change angle of the peak position of the irregular curve distribution bulge of the second etching interface 110 of the ridge toward the upper surface of the ridge 107b is γ, as shown in FIG. Figure 2 , 3 As shown, where: 30°≤δ≤α≤γ≤β≤90°.

[0035] The first etching interface 109 and the second etching interface 110 are distributed linearly; the angle between the first etching interface 109 of the ridge and the lower surface of the ridge is φ, the angle between the first etching interface 109 of the ridge and the upper surface of the ridge 107b is ψ, the angle between the second etching interface 110 of the ridge and the lower surface of the ridge 107b is ρ, and the angle between the first etching interface 109 of the ridge and the upper surface of the ridge 107b is θ. Figure 4 , 5 As shown, where: 100°≤θ≤ψ≤ρ≤φ≤180°;

[0036] The arc distribution of the first etching interface 109 and the second etching interface 110 has a hyperbolic function, an elliptical function, a parabolic function, and a conic function distribution. Specifically, as follows:

[0037] The linear distribution of the first etching interface 109 has a curve distribution of function y=Ax+B (A>0); the linear distribution of the second etching interface 110 has a curve distribution of function y=Cx+DC<0, wherein: C<0<A.

[0038] The arc distribution of the first etching interface 109 has a second three-quadrant curve distribution of the function y=xE / x (E>0); the arc distribution of the second etching interface 110 has a first four-quadrant curve distribution of the function y=xF / x (F>0).

[0039] like Figure 6 , 7 As shown, the arc distribution of the first etching interface 109 has a function y=G x +1 / (G x -1)0<G<1 fourth quadrant curve distribution; the arc distribution of the second etching interface 110 has a function y=H x +1 / (H x -1) The third quadrant curve distribution of F>1.

[0040] like Figure 6 , 7 As shown, the arc distribution of the first etching interface 109 has a function y=log a ((M+x) / (Mx))(0<a<1,M>0) The fourth quadrant curve distribution; The arc distribution of the second etching interface 110 has a function y=log b The third quadrant curve distribution of ((N+x) / (Nx))(b>1,N>0).

[0041] like Figure 6 , 7 As shown, the arc distribution of the first etching interface 109 has the functions y=l nx / x, y=l nx / e x , y=l nx / x+1 / x-1 any one of the curve distributions in the third quadrant; the arc distribution of the second etching interface 110 has a function y=e x / x、y=si nx / x 2 ,y=e x +e -x / (e x -e -x ) of any curve distribution.

[0042] The width of the ridge 107b is 0.5 to 500 micrometers; the thickness of the ridge 107b is 50 to 50000 nm.

[0043] The contact electrode 108 is any one or any combination of ITO, Au, Ag, Al, Ti, Pt, Ni, Cr, Zr, Ta, V, Hf, Nb, Pd, Rh, Mo, Cu, NiAu, TiPtAu, TiAlTiAu, CrAlCrPtAu.

[0044] The lower cladding layer 101, the lower waveguide layer 102, the active layer 103, the upper waveguide layer 104, the electron blocking layer 105, and the upper cladding layer 106 are 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, Ga 2 O 3 , BN, diamond, any one or any combination.

[0045] The substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO 2 Composite substrates, Mo, TiW, CuW, Cu, sapphire / AlN composite substrates, diamond, graphene, sapphire / SiN x , Sapphire / SiO 2 / SiN x Composite substrate, sapphire / SiN x / SiO 2 Composite substrate, magnesium aluminum spinel MgAl 2 O 4 、MgO、ZnO、ZrB 2 、LiAlO 2 and LiGaO 2 Any of the composite substrates.

[0046] In a specific embodiment, the beam quality factor M of the laser 2 From 2.36 to 1.24, a decrease of about 90%; the proportion of laser warping, falling off and breaking decreased from 23 to 6, a decrease of about 74%; the proportion of laser dead lamps decreased from 36 to 3, a decrease of about 92%, as shown in the following table;

[0047]

[0048] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A semiconductor laser chip, comprising, from bottom to top, a substrate (100), a lower cladding layer (101), a lower waveguide layer (102), an active layer (103), an upper waveguide layer (104), an electron blocking layer (105), and an upper cladding layer (106), characterized in that: The upper cladding layer (106) is etched to a distance of 5 to 500 nm from the electron blocking layer (105) by a photolithography process, a laser ridge (107b) is etched, and a contact electrode (108) is prepared above the ridge (107b); the ridge (107b) has a first etching interface (109) on the left and a second etching interface (110) on the right, and the first etching interface (109) and the second etching interface (110) are distributed in an irregular curve, an arc shape, or a linear shape.

2. A semiconductor laser chip according to claim 1, characterized in that: The first etching interface (109) and the second etching interface (110) are distributed in an irregular curve, and the irregular curve distribution bulges toward the center of the ridge (107b); the change angle of the peak position of the irregular curve distribution bulge of the first etching interface (109) of the ridge toward the lower surface of the ridge (107b) is α, the change angle of the peak position of the irregular curve distribution bulge of the first etching interface (109) of the ridge toward the upper surface of the ridge (107b) is β, the change angle of the peak position of the irregular curve distribution bulge of the second etching interface (110) of the ridge toward the lower surface of the ridge (107b) is δ, and the change angle of the peak position of the irregular curve distribution bulge of the second etching interface (110) of the ridge toward the upper surface of the ridge (107b) is γ, wherein: 30°≤δ≤α≤γ≤β≤90°.

3. The semiconductor laser chip according to claim 1, characterized in that: The first etching interface (109) and the second etching interface (110) are distributed linearly; the angle between the first etching interface (109) of the ridge and the lower surface of the ridge is φ, the angle between the first etching interface (109) of the ridge and the upper surface of the ridge (107b) is ψ, the angle between the second etching interface (110) of the ridge and the lower surface of the ridge (107b) is ρ, and the angle between the first etching interface (109) of the ridge and the upper surface of the ridge (107b) is θ, wherein: 100°≤θ≤ψ≤ρ≤φ≤180°.

4. The semiconductor laser chip according to claim 1, characterized in that: The arc distribution of the first etching interface (109) and the second etching interface (110) has a hyperbolic function, an elliptical function, a parabolic function, and a conic function distribution.

5. The semiconductor laser chip according to claim 3, characterized in that: The linear distribution of the first etching interface (109) has a curve distribution of function y=Ax+B (A>0); the linear distribution of the second etching interface (110) has a curve distribution of function y=Cx+D (C<0), wherein: C<0<A.

6. The semiconductor laser chip according to claim 4, characterized in that: The arc distribution of the first etching interface (109) has a second three-quadrant curve distribution of the function y=xE / x (E>0); the arc distribution of the second etching interface (110) has a first four-quadrant curve distribution of the function y=xF / x (F>0).

7. The semiconductor laser chip according to claim 4, characterized in that: The arc distribution of the first etching interface (109) has a function y=(G x +1) / (G x -1)(0<G<1) fourth quadrant curve distribution; the arc distribution of the second etching interface (110) has a function y=(H x +1) / (H x -1)(F>1) is the third quadrant curve distribution.

8. The semiconductor laser chip according to claim 4, characterized in that: The arc distribution of the first etching interface (109) has a function y=log a ((M+x) / (Mx))(0<a<1,M>0) fourth quadrant curve distribution; the arc distribution of the second etching interface (110) has a function y=log b The third quadrant curve distribution of ((N+x) / (Nx))(b>1,N>0).

9. The semiconductor laser chip according to claim 4, characterized in that: The arc distribution of the first etching interface (109) has the functions y=lnx / x, y=lnx / e x , y=lnx / x+1 / x-1 any one of the curve distributions in the third quadrant; the arc distribution of the second etching interface (110) has a function y=e x / x、y=sinx / x 2 ,y=(e x +e -x ) / (e x -e -x ) of any curve distribution.

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