Semiconductor lasers and their fabrication methods

Abstract

This application relates to a semiconductor laser and its fabrication method. The semiconductor laser includes a substrate, a bottom mirror structure, an active layer structure, and a top mirror structure; and an oxide trench formed in the top mirror structure. The semiconductor laser oxidizes a high-alumina material layer in the top mirror structure through the oxide trench; wherein the top mirror structure includes at least one high-alumina material layer, and the bottom of the oxide trench does not contact any of the high-alumina material layers. The solution of this application can improve the problem of melting at the bottom of the oxide trench.

Description

Technical Field

[0001] This application relates to the field of semiconductor laser technology, and in particular to a semiconductor laser and its fabrication method. Background Technology

[0002] Currently, semiconductor lasers are widely used in fields such as optical communication, 3D sensing, and lidar. Taking a vertical-cavity surface-emitting laser (VCSEL) as an example, the factors determining its high-speed performance or far-field divergence angle are the shape and size of the photoelectric confinement aperture. The photoelectric confinement aperture is usually prepared using a wet oxidation process. The core of the wet oxidation process is to use a high concentration of water and oxygen to oxidize the high-alumina component material layer in the laser, generating an insulating aluminum oxide layer with a low refractive index. The final shape of this layer determines the main performance characteristics of the laser (divergence angle, bandwidth, etc.).

[0003] Before performing the wet oxidation process, it is necessary to etch the oxidation trenches. However, during the etching process, it was found that some trench etching stopped at the top of the high aluminum layer or in the high aluminum layer. After the subsequent wet oxidation and passivation layer were made, during the reliability test, burn-through and melting occurred at the trenches. Summary of the Invention

[0004] Therefore, it is necessary to provide a semiconductor laser and its fabrication method to address the aforementioned technical problems.

[0005] In a first aspect, this application provides a semiconductor laser, including a substrate, a bottom mirror structure, an active layer structure, and a top mirror structure; and

[0006] Oxidation trenches are formed in the top reflector structure;

[0007] The semiconductor laser oxidizes the high-aluminum component material layer in the top reflector structure through the oxide trench.

[0008] The top reflector structure includes at least one high-alumina material layer, and the bottom of the oxide trench does not contact any of the high-alumina material layers.

[0009] In one embodiment, the high-aluminum component material layer is Al. x Ga （1-x） Material As, where 0.95≤x≤1.

[0010] In one embodiment, the top reflector structure includes multiple layers of high-alumina material, the oxidation trench penetrates a portion of the high-alumina material layers, and the penetrated high-alumina material layers are oxidized, while the remaining high-alumina material layers that are not penetrated do not contact the bottom of the oxidation trench.

[0011] In one embodiment, the number of oxide trenches is multiple, and the high-alumina component material layer is oxidized through multiple oxide trenches to form light-emitting holes with photoelectric confinement capabilities.

[0012] In one embodiment, the projection shape of each of the oxide trenches on the substrate is the same, or;

[0013] At least some of the oxide trenches have different projection shapes on the substrate than the remaining oxide trenches.

[0014] In one embodiment, the projection of the oxide trench onto the substrate is annular.

[0015] In one embodiment, it further includes:

[0016] The passivation layer filling the oxide trench; and

[0017] A metal heat dissipation layer is disposed on the passivation layer, and the metal heat dissipation layer is located at least within the oxide trench.

[0018] Secondly, this application also provides a method for fabricating a semiconductor laser, comprising:

[0019] An epitaxial structure is provided, comprising a substrate, a bottom mirror structure, an active layer structure, and a top mirror structure; the top mirror structure comprises at least one high-aluminum composition material layer.

[0020] A photochromic pattern is prepared on the epitaxial structure, and an oxide trench is obtained by etching the top reflector structure through the photochromic pattern.

[0021] The oxide trench is controlled to penetrate at least one of the high-alumina component material layers and not contact the remaining high-alumina component material layers, according to the position of each of the high-alumina component material layers in the top emitter structure; and

[0022] A wet oxidation process is performed on the exposed high-alumina material layer through the oxidation trenches.

[0023] In one embodiment, after completing the wet oxidation process, the process further includes:

[0024] A passivation layer is formed on the epitaxial structure; and

[0025] A metal heat dissipation layer is formed on the passivation layer to make electrical contact with the top reflector structure; wherein the metal heat dissipation layer also fills at least the oxide trench.

[0026] In one embodiment, the high-aluminum component material layer is Al. x Ga （1-x）Material As, where 0.95≤x≤1.

[0027] In this application, by controlling the etching depth during the etching of the oxide trench, the bottom of the final oxide trench does not remain in the high-alumina layer in the top reflector structure. Consequently, during the oxidation process, the high-alumina layer with non-oxidized apertures will not be oxidized into aluminum oxide. This avoids the passivation layer at the oxide trench from contacting aluminum oxide during the subsequent fabrication of the passivation layer. Instead, it contacts the originally planned low-alumina aluminum gallium arsenide material, thus improving the problem of melting at the bottom of the trench.

[0028] Thirdly, this application also provides an optical emitting component, which includes the aforementioned semiconductor laser.

[0029] Fourthly, this application provides a lidar, including an optical emitting module and an optical receiving module, wherein the optical emitting module adopts the aforementioned optical emitting component. Attached Figure Description

[0030] Figures 1a-1c This is a partial structural diagram of a semiconductor laser in conventional technology;

[0031] Figure 2 This is a schematic diagram of the structure of a semiconductor laser in one embodiment of this application;

[0032] Figure 3 This is a schematic diagram of the structure of a semiconductor laser according to another embodiment of this application.

[0033] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0035] It is understood that the terms "first," "second," etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first client may be referred to as a second client, and similarly, a second client may be referred to as a first client.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. "Multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. "Several" means at least one, such as one, two, etc., unless otherwise explicitly specified.

[0037] Currently, semiconductor lasers are widely used in fields such as optical communication, 3D sensing, and lidar. Taking a vertical-cavity surface-emitting laser (VCSEL) as an example, the factors determining its high-speed performance or far-field divergence angle are the shape and size of the photoelectric confinement aperture. The photoelectric confinement aperture is usually prepared using a wet oxidation process. The core of the wet oxidation process is to use a high concentration of water and oxygen to oxidize the high-alumina component material layer in the laser, generating an insulating aluminum oxide layer with a low refractive index. The final shape of this layer determines the main performance characteristics of the laser (divergence angle, bandwidth, etc.).

[0038] For reference Figures 1a-1c Before performing the wet oxidation process, etching of the oxide trench TH is required. However, during the etching process, it was found that some oxide trench TH etching stopped at the top or within the high-aluminum layer. After subsequent wet oxidation and passivation layer 150 fabrication, during reliability testing, burn-through and melting occurred at the oxide trench TH. The reason for this is that the passivation layer 150 (silicon nitride) at the bottom UD of the oxide trench TH was originally in contact with aluminum gallium arsenide (low aluminum composition). However, because the etching of the oxide trench TH stopped above or within the high-aluminum layer 132, this layer was easily oxidized to aluminum oxide 142 during wet oxidation. This caused the passivation layer (silicon nitride) at this point to contact aluminum oxide 142 instead of the aluminum gallium arsenide, leading to melting.

[0039] Based on this, such as Figure 2 As shown, this application provides a semiconductor laser, including a substrate SUB, a bottom mirror structure 110, an active layer structure 120, and a top mirror structure 130; and

[0040] An oxide trench TH is formed in the top reflector structure 130; the semiconductor laser oxidizes the high-aluminum material layer in the top reflector structure 130 through the oxide trench TH to form a photoelectric confinement layer 142.

[0041] The top reflector structure 130 includes at least one high-alumina material layer 132, and the bottom UD of the oxide trench TH does not contact any of the high-alumina material layers 132.

[0042] Specifically, in one embodiment, the substrate SUB is made of materials including, but not limited to, GaAs, InP, and Si. The bottom reflector structure 110 and the top reflector structure 130 may include films with periodically varying refractive indices to achieve efficient reflection or transmission of light within a specific wavelength range. The films with periodically varying refractive indices can be made of semiconductor materials, dielectric materials, metal-dielectric hybrid materials, etc. For example, the bottom reflector structure 110 may be an N-type semiconductor layer, and the top reflector structure 130 may be a P-type semiconductor layer. Alternatively, the bottom reflector structure 110 may be a P-type semiconductor layer, and the top reflector structure 130 may be an N-type semiconductor layer. Optionally, the materials of the N-type and P-type semiconductor layers may be, but are not limited to, GaAs, AlGaAs, etc. This is not a limitation; as long as the resonant cavity can be defined, it falls within the scope of this embodiment.

[0043] Specifically, the bottom mirror structure 110 and the top mirror structure 130 define a resonant cavity structure (not shown), which is the active layer structure 120. The active layer structure 120 includes a resonant cavity used to generate standing waves. Further, the bottom mirror structure 110 and the top mirror structure 130 define the resonant cavity structure of the semiconductor laser of this application; that is, the region between the bottom mirror structure 110 and the top mirror structure 130 is the resonant cavity. The resonant cavity is used to generate standing waves, which are waves formed by two coherent waves propagating in opposite directions along the same straight line and superimposing on each other. Specifically, when the two waves are in phase, their amplitudes are added together to form antinodes (i.e., wave crests). When the two waves are in opposite phases, their amplitudes are subtracted to form nodes (i.e., wave troughs). Therefore, the positions of the wave crests and troughs of the standing wave are fixed.

[0044] An active layer structure 120 contains a multi-quantum well structure located at the wave crest of the resonant cavity. Specifically, the multi-quantum well structure is used to generate stimulated emission photons, which are continuously reflected in the resonant cavity defined by the bottom mirror structure 110 and the top mirror structure 130, and are continuously amplified during the reflection process, thereby ultimately emitting laser light at a specific wavelength with sufficient energy.

[0045] The multiple quantum well structure is where laser gain amplification occurs. The center of the multiple quantum well structure can be aligned with the location of the strongest optical field (i.e., the peak of the resonant cavity) to achieve a greater amplification effect. Furthermore, there can be multiple multiple quantum well structures. When multiple multiple quantum well structures are included, their confinement factors within the same optical field are within the same preset range; that is, the confinement factors of each multiple quantum well structure are maintained at the same level, ensuring that each multiple quantum well structure contributes similarly to the light emission. Understandably, similar light emission contributions mean more uniform current injection in each multiple quantum well structure, which helps reduce the device's threshold current, thereby reducing power consumption and extending its lifespan. Moreover, when each multiple quantum well structure contributes similarly to the light emission, the distribution of charge carriers in each multiple quantum well structure will be more uniform, which helps reduce carrier recombination losses, thereby improving the overall luminous efficiency of the device.

[0046] Furthermore, the bottom mirror structure 110 may include a periodically stacked DBR structure, that is, multiple mirrors with an optical thickness of one-quarter of the lasing wavelength, with the multiple mirrors arranged alternately according to high and low refractive indices. The top mirror structure 130 also includes a periodically stacked DBR structure, that is, multiple mirrors with an optical thickness of one-quarter of the lasing wavelength, with the multiple mirrors arranged alternately according to high and low refractive indices. It is understood that the composition, stacking period number, etc., of the DBR structure of the bottom mirror structure 110 and the DBR structure of the top mirror structure 130 may be the same or different, and this embodiment is not limited thereto. The materials of the top mirror structure 130 and the bottom mirror structure 110 may be dielectric materials with electrical insulating properties, such as silicon nitride, silicon oxide, aluminum oxide, or titanium oxide. The materials of the top mirror structure 130 and the bottom mirror structure 110 may also be semiconductor materials, such as GaAs and AlGaAs.

[0047] In one embodiment, the high-aluminum component material layer 132 can be Al x Ga （1-x） The material is As, where 0.95 ≤ x ≤ 1. Specifically, the value of x can be 0.95, 0.96, 0.97, 0.98, 0.99, or even 1. When x is 1, the high-alumina component layer is AlAs. In other embodiments, the value of x can be further refined to the thousandths place, for example, x can be 0.952 or 0.955, etc., which will not be elaborated further in this application.

[0048] In one embodiment, the top reflector structure 130 may include multiple layers of high-alumina material 132. The oxide trench TH penetrates a portion of the high-alumina material layers 132, and the penetrated high-alumina material layers 132 are oxidized to form a photoelectric confinement layer 142. The remaining portions of the high-alumina material layers 132 that are not penetrated do not contact the bottom UD of the oxide trench TH. By controlling the bottom UD of the oxide trench TH to not contact the high-alumina material layers 132, it is prevented from being exposed to form aluminum oxide. Common oxide trench TH etching processes include plasma etching (ICP). It is readily known that by controlling the ICP etching time or power, the oxide trench TH can be stopped at a desired location.

[0049] The photoelectric confinement layer 142 is disposed adjacent to the active layer structure 120. Specifically, the photoelectric confinement layer 142 is located on the side of the corresponding active layer structure 120 away from the substrate SUB to restrict the flow of current, ensuring that the current flows only within the light-emitting region defined by the photoelectric confinement layer 142. This reduces unnecessary energy consumption, thereby reducing the threshold current and increasing the current density. Furthermore, the photoelectric confinement layer 142 can also confine the light field within the light-emitting region defined by the oxide confinement layer 132, reducing light scattering and diffraction, thereby optimizing the device's divergence angle and improving beam quality. Typically, the oxide confinement layer 132 is disposed at the location of the lowest light field intensity, i.e., at the trough of the standing wave, giving it a smaller confinement factor, which helps to reduce the device's divergence angle.

[0050] In one embodiment, the number of oxide trenches TH can be multiple. The high-alumina material layer 132 forms a light-emitting hole with photoelectric confinement capability after oxidation through multiple oxide trenches. The layer containing the light-emitting hole is the photoelectric confinement layer 142. Further, the projection shape of each oxide trench TH on the substrate SUB is the same, or at least some of the oxide trenches TH on the substrate SUB have different projection shapes than the remaining oxide trenches TH on the substrate SUB. In other words, the number and specific shape of the oxide trenches TH in this application are not limited. There can be multiple oxide trenches TH, and the shapes of the multiple oxide trenches TH can be the same or different. The shape and number of oxide trenches TH mainly determine the shape of the final light-emitting hole. This part is not the focus of the description in this application, so it will not be elaborated on further.

[0051] In one embodiment, the projection of the oxide trench TH onto the substrate SUB is annular. The shape of the light-emitting aperture corresponding to the annular oxide trench TH can be circular or elliptical.

[0052] In one embodiment, reference may also be made to Figure 3The semiconductor laser of this application may further include: a passivation layer 150 filled in the oxide trench TH; and a metal heat dissipation layer 160 disposed on the passivation layer 150, wherein the metal heat dissipation layer 160 is located at least in the oxide trench TH.

[0053] Specifically, such as Figure 3 As shown, passivation layer 150 is a layer that at least partially insulates the metal heat dissipation layer 160 from one or more other layers or features (e.g., sidewalls of trenches). Further, passivation layer 150 can be used to protect the top mirror structure 130. In some embodiments, passivation layer 150 may comprise, for example, silicon nitride (SiN), silicon dioxide (SiO2), a polymer dielectric, or another type of insulating material. In some embodiments, the thickness t of passivation layer 150 may range from about 0.92 × (λ / nd) to about 1.45 × (λ / nd), where λ is the wavelength of the vertical-cavity surface-emitting laser and nd is the refractive index of the dielectric material. More generally, the thickness T of the passivation layer 150 can be equal to the thickness t plus or minus a value corresponding to the wavelength of the semiconductor laser divided by a multiple of twice the refractive index of the dielectric material (e.g., T = t ± X × λ / (2 * nd), where 0.92 × (λ / nd) ≤ t ≤ 1.45 × (λ / nd), and X is an integer value such as 0, 1, 2, etc.). In some embodiments, the thickness T of the passivation layer 150 can vary by some amount depending on the VCSEL design (e.g., ±10 nm, ±15 nm). Thus, in some embodiments, the thickness of the passivation layer 150 is in the range of about 15 nm, which is equal to a value in the range from about 0.92 × (λ / nd) to about 1.45 × (λ / nd) plus or minus a value equal to X × λ / (2 * nd), where λ is the wavelength of the VCSEL, nd is the refractive index of the dielectric material, and X is an integer value.

[0054] Figure 3 The semiconductor laser may further include a metal heat sink 160, which is a top metal layer at the front side of the semiconductor laser. In some embodiments, the metal heat sink 160 may be a layer in direct contact with a heavily doped p-type electrical contact GaAs layer (e.g., through a via penetrating the passivation layer 150), or a layer in direct contact with an ohmic contact metal layer (not shown) disposed on the heavily doped p-type electrical contact GaAs layer. In some embodiments, the metal heat sink 160 may be used as an anode for the semiconductor laser. In some embodiments, the metal heat sink 160 may include electroplated metal (e.g., gold (Au)) and / or a seed metal used in the electroplating process.

[0055] Figure 3In this embodiment, the semiconductor laser may further include a bottom metal 170, which is a bottom metal layer located on the rear side of the semiconductor laser. In some embodiments, the bottom metal 170 may be a layer that is electrically in contact with the entire surface of the substrate SUB. In some embodiments, the metal heat dissipation layer 160 may be used as a cathode for the semiconductor laser. In some embodiments, the metal heat dissipation layer 160 may include electroplated metal (e.g., gold (Au)) and / or seed metal used in the electroplating process.

[0056] Figure 3 In this context, the semiconductor laser may also include a proton-injected region (not shown), which is a region that prevents free carriers from reaching the edge of the trench and / or isolates adjacent semiconductor lasers from each other (e.g., if the trench does not completely surround the semiconductor laser). The proton-injected region may include, for example, an ion implantation material, such as a hydrogen / proton implantation material or a similar implantation element, to reduce conductivity.

[0057] Figure 3 The number, arrangement, thickness, order, and symmetry of the layers are provided as examples. In practice, with... Figure 3 Compared to the layers shown, a semiconductor laser may include additional layers, fewer layers, different layers, layers with different constructions, or layers with different arrangements. For example, in some embodiments, a semiconductor laser may include a semiconductor layer (e.g., one or more p-type layers) above a top mirror structure 130 (e.g., instead of passivation layer 150). As another example, in some embodiments, a semiconductor laser may include an air interface (e.g., instead of passivation layer 150 and metal heat sink layer 160) above a top mirror structure 130. Additionally or alternatively, a set of layers (e.g., one or more layers) of a semiconductor laser may perform one or more functions described as being performed by another set of layers of a semiconductor laser, and any layer may include more than one layer.

[0058] Secondly, it can be used as a supplementary reference. Figure 2 and Figure 3 This application also provides a method for fabricating a semiconductor laser, comprising:

[0059] An epitaxial structure is provided, comprising a substrate, a bottom mirror structure, an active layer structure, and a top mirror structure; the top mirror structure comprises at least one high-aluminum composition material layer.

[0060] A photochromic pattern is prepared on the epitaxial structure, and an oxide trench is obtained by etching the top reflector structure through the photochromic pattern.

[0061] The oxide trench is controlled to penetrate at least one of the high-alumina component material layers and not contact the remaining high-alumina component material layers, according to the position of each of the high-alumina component material layers in the top emitter structure; and

[0062] A wet oxidation process is performed on the exposed high-alumina material layer through the oxidation trenches.

[0063] Specifically, the photochromic pattern can be, for example, a positive or negative photoresist. The shape of the photochromic pattern and the oxide trench (TH) can be the same or opposite, depending on whether it is a positive or negative photoresist. Common oxide trench (TH) etching processes include plasma etching (ICP). It is easy to know that by controlling the ICP etching time or power, the oxide trench (TH) can be stopped at the desired location.

[0064] In one embodiment, after completing the wet oxidation process, the process further includes:

[0065] A passivation layer is formed on the epitaxial structure; and

[0066] A metal heat dissipation layer is formed on the passivation layer to make electrical contact with the top reflector structure; wherein the metal heat dissipation layer also fills at least the oxide trench.

[0067] Specifically, a passivation layer 150 can be fabricated on the epitaxial structure using processes such as ALD, PECVD, or MOCVD. In addition, a metal heat dissipation layer can be fabricated by evaporation, sputtering, or electroplating. This metal heat dissipation layer is mainly used for electrical interconnection. Since metal has good thermal conductivity, its large-area filling in the oxide trench TH can improve the heat dissipation capacity of the semiconductor laser.

[0068] In one embodiment, the high-aluminum component material layer is Al. x Ga （1-x） The material is As, where 0.95 ≤ x ≤ 1. Specifically, the value of x can be 0.95, 0.96, 0.97, 0.98, 0.99, or even 1. When x is 1, the high-alumina component layer is AlAs. In other embodiments, the value of x can be further refined to the thousandths place, for example, x can be 0.952 or 0.955, etc., which will not be elaborated further in this application.

[0069] In summary, this application controls the etching depth during the etching of oxide trenches, ensuring that the bottom of the final oxide trench does not remain in the high-alumina layer of the top reflector structure. Consequently, during oxidation, the high-alumina layer with non-oxidized apertures is not oxidized into aluminum oxide. This avoids the passivation layer at the oxide trench from contacting aluminum oxide during subsequent passivation layer fabrication. Instead, it contacts the originally planned low-alumina aluminum gallium arsenide material, thus improving the problem of melting at the bottom of the trench.

[0070] Thirdly, this application also provides a light emitting component, which includes the aforementioned semiconductor laser. This light emitting component can be a light source in the light emitting module of a lidar system.

[0071] Fourthly, this application provides a lidar, including an optical emitting module and an optical receiving module, wherein the optical emitting module adopts the aforementioned optical emitting component.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The above-described embodiments are merely illustrative of several implementation methods of the embodiments of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the embodiments of this application, and these all fall within the protection scope of the embodiments of this application. Therefore, the protection scope of the patent for the embodiments of this application should be determined by the appended claims.

Claims

1. A semiconductor laser, characterized in that, It includes a substrate, a bottom mirror structure, an active layer structure, and a top mirror structure; as well as Oxidation trenches are formed in the top reflector structure; The semiconductor laser oxidizes the high-aluminum component material layer in the top reflector structure through the oxide trench. The top reflector structure includes at least one high-alumina material layer, and the bottom of the oxide trench does not contact any of the high-alumina material layers; the high-alumina material layer is Al. x Ga （1-x） Material As, where 0.95≤x≤1; The top reflector structure includes multiple layers of high-alumina material. The oxidation trench penetrates a portion of the high-alumina material layers, and the penetrated high-alumina material layers are oxidized. The remaining high-alumina material layers that are not penetrated do not contact the bottom of the oxidation trench.

2. The semiconductor laser according to claim 1, characterized in that, The number of oxidation trenches is multiple, and the high-alumina component material layer forms a light-emitting hole with photoelectric confinement capability after being oxidized through multiple oxidation trenches.

3. The semiconductor laser according to claim 2, characterized in that, The projection shapes of all the oxide trenches on the substrate are the same, or; At least some of the oxide trenches have different projection shapes on the substrate than the remaining oxide trenches.

4. The semiconductor laser according to claim 1, characterized in that, The projection of the oxide trench on the substrate is annular.

5. The semiconductor laser according to any one of claims 1-4, characterized in that, Also includes: A passivation layer filling the oxide trench; as well as A metal heat dissipation layer is disposed on the passivation layer, and the metal heat dissipation layer is located at least within the oxide trench.

6. A method for fabricating a semiconductor laser, characterized in that, include: An epitaxial structure is provided, the epitaxial structure including a substrate, a bottom mirror structure, an active layer structure and a top mirror structure; The top reflector structure comprises multiple layers of high-alumina material; the high-alumina material layers are Al. x Ga （1-x） Material As, where 0.95≤x≤1; A photochromic pattern is prepared on the epitaxial structure, and an oxide trench is obtained by etching the top reflector structure through the photochromic pattern. The oxide trench is controlled to at least penetrate a portion of the high-alumina component material layer according to the position of each of the high-alumina component material layers in the top emitter structure, and the bottom of the oxide trench does not contact the remaining high-alumina component material layers; and A wet oxidation process is performed on the exposed high-alumina material layer through the oxidation trenches.

7. The method for fabricating a semiconductor laser according to claim 6, characterized in that, After completing the wet oxidation process, the following is also included: A passivation layer is formed on the epitaxial structure; and A metal heat dissipation layer is formed on the passivation layer to make electrical contact with the top reflector structure; wherein the metal heat dissipation layer also fills at least the oxide trench.

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