阅读说明：本技术 外延晶片以及半导体激光器 (Epitaxial wafer and semiconductor laser ) 是由 陈长安 郑兆祯 于 2019-01-04 设计创作，主要内容包括：本发明涉及半导体技术领域,公开了一种外延晶片以及半导体激光器。该外延晶片包括：衬底；功能层,功能层位于衬底上；其中,功能层中的至少部分层体掺杂有Mg；发光层,发光层位于功能层中,功能层用于驱动发光层发光。通过上述方式,本发明能够提高应用本发明外延晶片的激光器的特征温度,进而提高其电光转换效率。(The invention relates to the technical field of semiconductors, and discloses an epitaxial wafer and a semiconductor laser. The epitaxial wafer includes: a substrate; the functional layer is positioned on the substrate; wherein at least part of the functional layer is doped with Mg; and the light emitting layer is positioned in the functional layer, and the functional layer is used for driving the light emitting layer to emit light. Through the mode, the characteristic temperature of the laser applying the epitaxial wafer can be improved, and the electro-optic conversion efficiency of the laser can be further improved.)

1. An epitaxial wafer, characterized in that it comprises:

a substrate;

a functional layer on the substrate; wherein at least part of the functional layers is doped with Mg;

the light emitting layer is positioned in the functional layer, and the functional layer is used for driving the light emitting layer to emit light.

2. The epitaxial wafer of claim 1, wherein the functional layers include a first functional layer and a second functional layer, and the first functional layer, the light-emitting layer and the second functional layer are sequentially laminated on the substrate in a direction close to the substrate.

3. The epitaxial wafer of claim 2, wherein the first functional layer comprises a first waveguide layer and a first confinement layer, the first waveguide layer is located on a side of the light emitting layer away from the second functional layer, the first confinement layer is located on a side of the first waveguide layer away from the light emitting layer, and the first waveguide layer and the first confinement layer are doped with Mg.

4. The epitaxial wafer of claim 3, wherein the Mg concentration in the first waveguide layer is less than the Mg concentration in the first confinement layer.

5. The epitaxial wafer of claim 3, wherein the first confinement layer comprises a first sub-confinement layer and a second sub-confinement layer, the first sub-confinement layer being located on a side of the first waveguide layer remote from the light-emitting layer, the second sub-confinement layer being located on a side of the first sub-confinement layer remote from the first waveguide layer; wherein the first sub-confinement layer is doped with Mg and the second sub-confinement layer is doped with Zn.

6. The epitaxial wafer of claim 5, wherein the first confinement layer further comprises a barrier layer between the first sub-confinement layer and the second sub-confinement layer.

7. The epitaxial wafer of claim 6, wherein the barrier layer comprises a first barrier layer doped with Mg and a second barrier layer doped with Zn, the barrier layers being superlattice structures in which at least one of the first barrier layers and at least one of the second barrier layers are alternately stacked and paired.

8. The epitaxial wafer of claim 6, wherein the first functional layer further comprises a contact layer located on a side of the second sub-confinement layer away from the first sub-confinement layer, a transition layer being disposed between the contact layer and the second sub-confinement layer, the barrier layer and the transition layer being configured to increase a distance between the contact layer and the light-emitting layer; wherein the contact layer is doped with Zn.

9. The epitaxial wafer of claim 6, wherein the barrier layer is comprised of undoped AlGaInP material.

10. The epitaxial wafer of any of claims 2 to 9, wherein the first functional layer is an N-type semiconductor layer and the second functional layer is a P-type semiconductor layer; or the first functional layer is a P-type semiconductor layer, and the second functional layer is an N-type semiconductor layer.

11. A semiconductor laser, characterized in that the semiconductor laser comprises an epitaxial wafer according to any one of claims 1 to 10.

Technical Field

The present invention relates to the field of semiconductor technology, and in particular, to an epitaxial wafer and a semiconductor laser.

Background

AlGaInP quaternary compound materials are widely used in high-brightness red light emitting diodes and semiconductor lasers, and have become the mainstream materials of red light emitting devices. However, the AlGaInP material system itself has its disadvantages compared to the AlGaAs materials used earlier: the conduction band step of the AlGaInP/GaInP heterojunction is very small, the maximum value is about 270meV, and is less than 350meV of the AlGaAs material, so that the electron barrier is relatively low, leakage current is easy to form, the threshold current of the laser is increased, and the laser is particularly obvious in high-temperature and high-current operation. And the thermal resistance of the AlGaInP material is far higher than that of the AlGaAs material due to alloy scattering, so that more heat is generated during working, and the junction temperature and the cavity surface temperature are easily overhigh. Meanwhile, the effective mass and state density of AlGaInP material carriers are higher than those of AlGaAs materials, and higher transparent current density is needed during lasing. The characteristic temperature of the laser using the AlGaInP material system is low due to the reasons, and the electro-optic conversion efficiency is low when the laser is continuously operated.

Disclosure of Invention

In view of the above, the present invention provides an epitaxial wafer and a semiconductor laser, which can increase the characteristic temperature of the laser using the epitaxial wafer of the present invention, and further increase the electro-optic conversion efficiency.

In order to solve the technical problems, the invention adopts a technical scheme that: providing an epitaxial wafer comprising: a substrate; the functional layer is positioned on the substrate; wherein at least part of the functional layer is doped with Mg; and the light emitting layer is positioned in the functional layer, and the functional layer is used for driving the light emitting layer to emit light.

In an embodiment of the present invention, the functional layers include a first functional layer and a second functional layer, and the first functional layer, the light emitting layer, and the second functional layer are sequentially stacked on the substrate in a direction close to the substrate.

In an embodiment of the present invention, the first functional layer includes a first waveguide layer and a first confinement layer, the first waveguide layer is located on a side of the light emitting layer away from the second functional layer, the first confinement layer is located on a side of the first waveguide layer away from the light emitting layer, and the first waveguide layer and the first confinement layer are doped with Mg.

In an embodiment of the present invention, the Mg concentration in the first waveguide layer is less than the Mg concentration in the first confinement layer.

In an embodiment of the invention, the first confinement layer includes a first sub-confinement layer and a second sub-confinement layer, the first sub-confinement layer is located on a side of the first waveguide layer away from the light-emitting layer, and the second sub-confinement layer is located on a side of the first sub-confinement layer away from the first waveguide layer; wherein the first sub-confinement layer is doped with Mg, and the second sub-confinement layer is doped with Zn.

In an embodiment of the invention, the first confinement layer further includes a blocking layer, and the blocking layer is located between the first sub-confinement layer and the second sub-confinement layer.

In an embodiment of the invention, the barrier layers include a first barrier layer doped with Mg and a second barrier layer doped with Zn, and the barrier layers are superlattice structures in which at least one first barrier layer and at least one second barrier layer are alternately stacked and paired.

In an embodiment of the invention, the first functional layer further includes a contact layer, the contact layer is located on one side of the second sub-confinement layer, which is far away from the first sub-confinement layer, a transition layer is arranged between the contact layer and the second sub-confinement layer, and the barrier layer and the transition layer are used for increasing a distance between the contact layer and the light-emitting layer; wherein the contact layer is doped with Zn.

In one embodiment of the present invention, the barrier layer is made of undoped AlGaInP material.

In an embodiment of the invention, the first functional layer is an N-type semiconductor layer, and the second functional layer is a P-type semiconductor layer; or the first functional layer is a P-type semiconductor layer, and the second functional layer is an N-type semiconductor layer.

In order to solve the technical problem, the invention adopts another technical scheme that: there is provided a semiconductor laser including an epitaxial wafer as set forth in the above embodiments.

The invention has the beneficial effects that: in contrast to the prior art, the present invention provides an epitaxial wafer comprising a substrate and a functional layer on the substrate. The epitaxial wafer further comprises a light emitting layer, wherein the light emitting layer is positioned in a functional layer, and the functional layer is used for driving the light emitting layer to emit light. At least part of the functional layer is doped with Mg, so that the quasi-Fermi level position of the at least part of the functional layer is improved, the effective barrier for blocking current leakage is improved, the characteristic temperature of a laser applying the epitaxial wafer can be improved, and the electro-optic conversion efficiency of the laser can be improved.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of an epitaxial wafer of the present invention;

FIG. 2 is a schematic view of a conduction band structure of the epitaxial wafer shown in FIG. 1;

FIG. 3 is a schematic structural view of another embodiment of an epitaxial wafer of the present invention;

FIG. 4 is a schematic view of a conduction band structure of the epitaxial wafer shown in FIG. 3;

FIG. 5 is a schematic structural diagram of an embodiment of a first confinement layer of the invention;

FIG. 6 is a schematic structural diagram of an embodiment of a barrier layer of the present invention;

FIG. 7 is a schematic view of an embodiment of a conduction band structure of an epitaxial wafer according to the present invention;

fig. 8 is a schematic structural diagram of an embodiment of a semiconductor laser of the present invention.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

In order to solve the technical problems of low characteristic temperature and low electro-optic conversion efficiency of a laser in the prior art, an embodiment of the present invention provides an epitaxial wafer, including: a substrate; the functional layer is positioned on the substrate; wherein at least part of the functional layer is doped with Mg; and the light emitting layer is positioned in the functional layer, and the functional layer is used for driving the light emitting layer to emit light.

As described in detail below.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an epitaxial wafer according to an embodiment of the invention.

In an embodiment, the epitaxial wafer comprises a substrate 1 and a functional layer 2 located on the substrate 1, and the epitaxial wafer further comprises a light emitting layer 3, the light emitting layer 3 is located in the functional layer 2, and the functional layer 2 is used for driving the light emitting layer 3 to emit light so as to meet the use requirement. For example, an epitaxial wafer is applied to a laser, and the light emitting layer 3 is used to generate sufficient optical gain and emit light to achieve a laser emission wavelength required for laser output.

At least part of the functional layer 2 of the epitaxial wafer is doped with Mg to improve the quasi-Fermi level position of the at least part of the functional layer, so that an effective barrier for blocking current leakage is improved, current leakage is reduced, the electro-optic conversion efficiency is improved, and heat generation is reduced.

In an embodiment, the functional layer 2 comprises a first functional layer 21 and a second functional layer 22. The first functional layer 21, the light emitting layer 3 and the second functional layer 22 are sequentially stacked on the substrate 1 along a direction close to the substrate 1, that is, the second functional layer 22 is positioned on the substrate 1, the light emitting layer 3 is positioned on the second functional layer 22, and the first functional layer 21 is positioned on the light emitting layer 3.

Further, the first functional layer 21 includes a first waveguide layer 211 and a first confinement layer 212. The first waveguide layer 211 is located at a side of the light emitting layer 3 remote from the second functional layer 22, the first confinement layer 212 is located at a side of the first waveguide layer 211 remote from the light emitting layer 3, and the first waveguide layer 211 and the first confinement layer 212 are doped with Mg for increasing the quasi-fermi level position of the first waveguide layer 211 and the first confinement layer 212, thereby increasing an effective barrier against current leakage.

Note that the Mg concentration doped in the first waveguide layer 211 is smaller than the Mg concentration in the first confinement layer 212. The inventors have found that the concentration of Mg doped in the first waveguide layer 211 and the first confinement layer 212 is set so as to maximize the effective barrier of the first waveguide layer 211 and the first confinement layer 212, thereby minimizing the leakage current. In addition, the first limit layer 212 with high doping can further improve the conductivity of the material, reduce the series resistance of the laser, improve the electro-optic conversion efficiency of the laser and reduce heat generation.

Further, the second functional layer 22 includes a second waveguide layer 221 and a second confinement layer 222. The second waveguide layer 221 is located on a side of the light-emitting layer 3 remote from the first functional layer 21, and the second confinement layer 222 is located on a side of the second waveguide layer 221 remote from the light-emitting layer 3. Wherein the second confinement layer 222 is located on the substrate 1.

It should be noted that the first waveguide layer 211 and the second waveguide layer 221 are used for transporting electrons or holes to the light-emitting layer 3, the electrons and the holes meet and pair at the light-emitting layer 3, and the bonded electrons and holes release energy and are absorbed by the light-emitting layer 3, so that the light-emitting layer 3 radiates laser light. The refractive indices of the first confinement layer 212 and the second confinement layer 222 are smaller than the first waveguide layer 211 and the second waveguide layer 221. The laser light radiated by the light-emitting layer 3 passes through the first waveguide layer 211 and the second waveguide layer 221, and is totally reflected at the interfaces of the first waveguide layer 211, the second waveguide layer 221, the first confinement layer 212, and the second confinement layer 222, so that the optical field of the laser light radiated by the light-emitting layer 3 is confined in the light-emitting layer 3, the first waveguide layer 211, and the second waveguide layer 221.

The first functional layer 21 further comprises a transition layer 213 and a contact layer 214. The transition layer 213 is located on a side of the first confinement layer 212 away from the first waveguide layer 211, and the contact layer 214 is located on a side of the transition layer 213 away from the first confinement layer 212. The contact layer 214 serves as a medium for connecting the epitaxial wafer to an external power supply structure or a structure functioning as a power supply, and serves to introduce an electric signal (electron or hole) for driving the light-emitting layer 3 to emit light. The transition layer 213 serves as a transition medium between the first confinement layer 212 and the contact layer 214.

It is understood that the first functional layer 21 may be an N-type semiconductor layer; correspondingly, the second functional layer 22 is a P-type semiconductor layer. Or the first functional layer 21 is a P-type semiconductor layer; correspondingly, the second functional layer 22 is an N-type semiconductor layer.

The specific structure of the epitaxial wafer is described below by taking the first functional layer 21 as a P-type semiconductor layer and the second functional layer 22 as an N-type semiconductor layer as an example:

since the second functional layer 22 is located between the substrate 1 and the light-emitting layer 3, the substrate 1 also needs to be an N-type semiconductor matched to the second functional layer 22. Specifically, the substrate 1 may be an N-type GaAs single crystal wafer, which serves as a base of an upper layer structure of an epitaxial wafer.

The second confinement layer 222 of the second functional layer 22 is N-type undoped Al matched to N-type GaAs_xIn_1-xP, the thickness is 500-5000 nm. The second waveguide layer 221 is N-type undoped (Al)_yGa_1-y)_xIn_1-xP, the thickness is 50-250 nm.

Light-emitting layer 3, i.e. quantum well layer, of Ga_zIn_1-zP, the thickness is 2-200 nm. The wavelength of the laser emitted by the light-emitting layer 3 is 620 to 670 nm.

The first waveguide layer 211 of the first functional layer 21 is P-type (Al)_yGa_1-y)_xIn_1-xP with a thickness of 50-250 nm, the first waveguide layer 211 is doped with Mg with a Mg doping concentration of 5 × 10¹⁷cm^-3. The first confinement layer 212 is P-type Al_xIn_1-xP, the thickness of which is 500-5000 nm. The first confinement layer 212 is doped with Mg, wherein the Mg is doped at a concentration of3×10¹⁸cm^-3. It can be seen that the Mg concentration doped in the first waveguide layer 211 is less than the Mg concentration in the first confinement layer 212.

The transition layer 213 and the contact layer 214 correspond to the first functional layer 21, and when the first functional layer 21 is a P-type semiconductor layer, the transition layer 213 and the contact layer 214 correspond to the P-type semiconductor layer, and when the first functional layer 21 is an N-type semiconductor layer, the transition layer 213 and the contact layer 214 correspond to the N-type semiconductor layer. In the present embodiment, the transition layer 213 is P-type undoped (Al)_yGa_1-y)_xIn_{1- x}P, the thickness of which is 50 to 250 nm. The contact layer 214 is P-type undoped GaAs and has a thickness of 100 to 500 nm. The contact layer 214 may be doped, for example with Mg, Zn, etc., to improve the conductive properties of the contact layer 214.

Wherein 0< x <0.52, 0< y <0.8, 0.3< z <0.7 (the same applies hereinafter). The inventor finds that the AlGaInP material has a good physical or chemical property by using the element ratio, so as to meet the practical use requirement of the epitaxial wafer.

Fig. 2 shows a conduction band structure of the epitaxial wafer explained in the present embodiment, wherein a segment represents a concentration of Mg doped in the first waveguide layer 211, and a segment B represents a concentration of Mg doped in the first confinement layer 212. It can be seen that, by doping Mg with different concentrations in the first waveguide layer 211 and the first confinement layer 212, where the Mg concentration doped in the first waveguide layer 211 is less than the Mg concentration in the first confinement layer 212, the conduction band orders of the first waveguide layer 211 and the first confinement layer 212 can be effectively improved, current leakage is reduced, and the electro-optic conversion efficiency of the epitaxial wafer is improved.

Referring to fig. 3, fig. 3 is a schematic structural diagram of an epitaxial wafer according to another embodiment of the invention.

Since the activation energy (190meV) of Mg is high, the efficiency of generating electron or hole carriers in the Mg-doped functional layer 2 is not high, and the effect of improving the photoelectric conversion efficiency of the epitaxial wafer by doping Mg is limited. And the activation energy (100-125 meV) of Zn is less than that of Mg, so that the Zn-doped functional layer 2 has higher efficiency of generating electron or hole carriers, and the effect of improving the electro-optic conversion efficiency of the epitaxial wafer is better than that of Mg.

In view of this, the present embodiment is different from the above embodiments in that the first confinement layer 212 includes a first sub-confinement layer 2121 and a second sub-confinement layer 2122. The first sub-confinement layer 2121 is located on a side of the first waveguide layer 211 remote from the light-emitting layer 3, and the second sub-confinement layer 2122 is located on a side of the first sub-confinement layer 2121 remote from the first waveguide layer 211.

Since Zn has a higher diffusion coefficient in AlGaInP-based materials than Mg, it easily diffuses into the light-emitting layer 3 to cause light absorption, which adversely affects the performance of the epitaxial wafer for radiating laser light. In view of this, in the present embodiment, the first sub-confinement layer 2121 relatively close to the first waveguide layer 211 is doped with Mg, and the second sub-confinement layer 2122 relatively far from the first waveguide layer 211 is doped with Zn. Therefore, the electro-optic conversion efficiency of the epitaxial wafer is improved by doping Mg and Zn, and the Zn is effectively prevented from diffusing into the light-emitting layer 3 to influence the performance of the light-emitting layer 3.

As described in the above embodiment, the first functional layer 21 may be an N-type semiconductor layer; correspondingly, the second functional layer 22 is a P-type semiconductor layer. Or the first functional layer 21 is a P-type semiconductor layer; correspondingly, the second functional layer 22 is an N-type semiconductor layer.

The specific structure of the epitaxial wafer is described below by taking the first functional layer 21 as a P-type semiconductor layer and the second functional layer 22 as an N-type semiconductor layer as an example:

since the second functional layer 22 is located between the substrate 1 and the light-emitting layer 3, the substrate 1 also needs to be an N-type semiconductor matched to the second functional layer 22. Specifically, the substrate 1 may be an N-type GaAs single crystal wafer, which serves as a base of an upper layer structure of an epitaxial wafer.

The second confinement layer 222 of the second functional layer 22 is N-type undoped Al matched to N-type GaAs_xIn_1-xP, the thickness is 500-5000 nm. The second waveguide layer 221 is N-type undoped (Al)_yGa_1-y)_xIn_1-xP, the thickness is 50-250 nm.

Light-emitting layer 3, i.e. quantum well layer, of Ga_zIn_1-zP, thickness2 to 200 nm. The wavelength of the laser emitted by the light-emitting layer 3 is 620 to 670 nm.

The first waveguide layer 211 of the first functional layer 21 is P-type (Al)_yGa_1-y)_xIn_1-xP with a thickness of 50-250 nm, the first waveguide layer 211 is doped with Mg with a Mg doping concentration of 5 × 10¹⁷cm^-3. The first sub-confinement layer 2121 of the first confinement layer 212 is P-type Al_xIn_1-xP with a thickness of 10-500 nm, the first sub-confinement layer 2121 is doped with Mg with a doping concentration of 3 × 10¹⁸cm^-3. The second sub-confinement layer 2122 is P-type Al_xIn_1-xP with a thickness of 1000 to 7000nm, the second sub-confinement layer 2122 is doped with Zn with a doping concentration of 3 × 10¹⁸cm^-3。

It should be noted that the Mg doped in the first sub-confinement layer 2121 in this embodiment has the same concentration as the Zn doped in the second sub-confinement layer 2122, and is equal to the Mg doped in the first confinement layer 212 in the above-described embodiment. In order to make the concentration of the doped atoms of the first confinement layer 212 greater than that of the first waveguide layer 211, the corresponding technical effects have been described in detail in the above embodiments, and are not repeated herein.

The transition layer 213 and the contact layer 214 correspond to the first functional layer 21, and when the first functional layer 21 is a P-type semiconductor layer, the transition layer 213 and the contact layer 214 correspond to the P-type semiconductor layer, and when the first functional layer 21 is an N-type semiconductor layer, the transition layer 213 and the contact layer 214 correspond to the N-type semiconductor layer. In the present embodiment, the transition layer 213 is P-type undoped (Al)_yGa_1-y)_xIn_{1- x}P, the thickness of which is 50 to 250 nm. The contact layer 214 is P-type undoped GaAs and has a thickness of 100 to 500 nm. Of course, the contact layer 214 may also be doped, such as Mg, Zn, etc., to improve the conductivity of the contact layer 214.

Fig. 4 shows the conduction band structure of the epitaxial wafer described in the present embodiment, wherein the a-segment represents the Mg doping concentration in the first waveguide layer 211, and the C-segment represents the Mg doping concentration of the first sub-confinement layer 2121 and the Zn doping concentration of the second sub-confinement layer 2122. It can be seen that by doping Mg in the first sub-confinement layer 2121 of the first confinement layer 212 and Zn in the second sub-confinement layer 2122, Zn improves the efficiency of generating carriers in the epitaxial wafer, thereby improving the electro-optic conversion efficiency of the epitaxial wafer, and also effectively preventing Zn from diffusing into the light-emitting layer 3 and affecting the performance of the light-emitting layer 3.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a first confinement layer according to an embodiment of the invention.

In an alternative embodiment, the first confinement layer 212 further includes a barrier layer 4. The barrier layer 4 is located between the first sub-confinement layer 2121 and the second sub-confinement layer 2122, and is used for preventing the Zn in the second sub-confinement layer 2122 from diffusing into the light-emitting layer 3. Meanwhile, in the case where the contact layer 214 is doped with Zn, the barrier layer 4 can also prevent Zn in the contact layer 214 from diffusing into the light-emitting layer 3.

Further, the contact layer 214 of the first functional layer 21 is located on the side of the second sub-confinement layer 2122 away from the first sub-confinement layer 2121, the transition layer 213 is disposed between the contact layer 214 and the second sub-confinement layer 2122, and the barrier layer 4 and the transition layer 213 are used for increasing the distance between the contact layer 214 and the light-emitting layer 3. In the case that the contact layer 214 is doped with Zn, the distance between the contact layer 214 and the light emitting layer 3 is increased, so that Zn is difficult to diffuse into the light emitting layer 3, and the influence of Zn doped in the contact layer 214 on the laser performance of the light emitting layer 3 is avoided.

Preferably, AlGaInP-based material or the like may be used for the barrier layer 4, and the barrier layer 4 may be formed of undoped AlGaInP material. The inventors have found through a large number of experiments that the barrier layer 4 made of an AlGaInP-based material is more effective in preventing Zn from diffusing into the light-emitting layer 3 than other materials.

Referring to fig. 6, fig. 6 is a schematic structural diagram of an embodiment of a barrier layer according to the present invention.

In an alternative embodiment, unlike the above-described embodiments, is: the barrier layer 4 includes a first barrier layer 41 and a second barrier layer 42. The first barrier layer 41 is doped with Mg, and the second barrier layer 42 is doped with Zn. The barrier layer 4 has a superlattice structure in which at least one first barrier layer 41 and at least one second barrier layer 42 are alternately stacked and paired.

That is, the barrier layer 4 includes at least one first barrier layer 41 and at least one second barrier layer 42, and one first barrier layer 41 and one second barrier layer 42 are paired, that is, the number of layers of the first barrier layer 41 and the second barrier layer 42 is equal. The barrier layer 4 also exhibits the form of first barrier layers 41 and second barrier layers 42 stacked alternately, that is, the first barrier layers 41 and the second barrier layers 42 of the same pair are stacked on each other and stacked on each other with the first barrier layers 41 and the second barrier layers 42 of the other pairs, and as a whole, the first barrier layers 41, the second barrier layers 42, and the first barrier layers 41 … … are in the form of stacked layers in this order.

Further, the first barrier layer 41 is a superlattice structure of AlGaInP doped with Mg, and the second barrier layer 42 is a superlattice structure of AlGaInP doped with Zn, wherein the doping concentration of Mg or Zn is 1 × 10¹⁷～5×10¹⁸cm^-3. The first barrier layer 41 and the second barrier layer 42 have the same thickness and are 0.5 to 20 nm. The barrier layer 4 includes 1 to 20 pairs of a first barrier layer 41 and a second barrier layer 42. The specific structure of the superlattice structure is within the understanding of those skilled in the art, and thus the description thereof is omitted here.

Because the diffusion coefficient of Mg or Zn in the AlGaInP material of the superlattice structure is relatively low and has a steeper doping edge, the doping atoms diffused into the light-emitting layer 3 can be reduced, thereby reducing the influence on the performance of the light-emitting layer 3 caused by the diffusion of the doping atoms into the light-emitting layer 3. In order to further reduce the diffusion of doping atoms, such as Zn, into the light emitting layer 3, the first barrier layer 41 of the first layer is located on the first sub-confinement layer 2121, and the subsequent layer bodies of the other barrier layers 4 are sequentially stacked on the first barrier layer 41 to increase the distance of the diffusion of Zn into the light emitting layer 3, thereby reducing the diffusion of Zn into the light emitting layer 3.

Fig. 7 shows a conduction band structure of the epitaxial wafer described in this embodiment, wherein the segment a represents the concentration of Mg doped in the first waveguide layer 211, and the segment D represents the superlattice structure of the pair of the first barrier layer 41 and the second barrier layer 42 of the barrier layer 4 to reduce the diffusion of Zn doped atoms. It can be seen that in this embodiment, by adding the barrier layer 4, the dopant atoms can be effectively prevented from diffusing into the light-emitting layer 3. Meanwhile, the barrier layer 4 adopts a superlattice structure formed by the first barrier layer 41 and the second barrier layer 42 in pair, so that the diffusion coefficient of doped atoms in the superlattice structure is relatively low, the doped atoms are further prevented from diffusing into the light-emitting layer 3, and the influence on the performance of the light-emitting layer 3 caused by the doped atoms diffusing into the light-emitting layer 3 is reduced.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a semiconductor laser according to an embodiment of the invention.

In one embodiment, the semiconductor laser 5 includes an epitaxial wafer 51, and the epitaxial wafer 51 is excited to radiate laser light to realize the function of the semiconductor laser 5 to output laser light. The specific structure of the epitaxial wafer 51 has been described in detail in the above embodiments, and will not be described herein again.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.