Semiconductor laser preparation method and semiconductor laser

Abstract

The invention relates to the technical field of lasers, in particular to a semiconductor laser preparation method and a semiconductor laser. The invention provides a preparation method of a semiconductor laser. Preparing an epitaxial wafer; forming a first metal layer on the epitaxial wafer; forming a patterned second metal layer on the first metal layer; forming a third metal layer on the patterned second metal layer; and etching the first metal layer and the third metal layer to form a patterned first metal layer and a patterned third metal layer. The three-layer patterned metal layer structure is formed by adopting the two-time patterning processing step, and compared with an existing mode that one-time patterning processing step is needed for preparing each patterned metal layer, the etching step is reduced, and the preparation efficiency and the device yield of the semiconductor laser are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lasers, and in particular to a method for preparing a semiconductor laser and a semiconductor laser. Background Art

[0002] In the process of preparing semiconductor lasers, it is necessary to carry out metal patterning operations to form ohmic contact layers and electrodes according to the device structure design; conventional metal patterning operations usually adopt the method of photoresist stripping; currently, in the process of preparing semiconductor lasers, it is necessary to prepare multiple layers of metal patterns, and each layer of patterned metal layer needs to be patterned once. The numerous steps affect the efficiency of the metal layer patterning operation, and thus affect the preparation efficiency of the entire semiconductor laser. Summary of the invention

[0003] (I) The technical problem to be solved by the present invention is that in the existing semiconductor laser manufacturing process, each patterned metal layer needs to be prepared through a patterning process, and the process is complicated, which affects the efficiency of the metal layer patterning process.

[0004] (II) Technical solution In order to solve the above technical problems, an embodiment of the present invention provides a method for preparing a semiconductor laser, comprising the following steps: Preparation of epitaxial wafers; forming a first metal layer on the epitaxial wafer; forming a patterned second metal layer on the first metal layer; forming a third metal layer on the patterned second metal layer; The first metal layer and the third metal layer are etched to form a patterned first metal layer and a patterned third metal layer.

[0005] According to one embodiment of the present invention, preparing an epitaxial wafer includes: forming a trench on the epitaxial wafer; Plating a dielectric layer on the inner wall of the groove and the upper surface of the epitaxial wafer; An electrode window is formed on the dielectric layer.

[0006] According to one embodiment of the present invention, forming a patterned second metal layer on the first metal layer includes: Coating a negative photoresist on the upper surface of the first metal layer according to a preset pattern, electroplating to form a second metal layer, and stripping the negative photoresist to form a patterned second metal layer; Wherein, the patterned second metal layer at least covers the electrode window.

[0007] According to one embodiment of the present invention, etching the first metal layer and the third metal layer to form a patterned first metal layer and a patterned third metal layer includes: The first metal layer and the third metal layer are etched by ion beams using a multi-directional etching process to form a patterned first metal layer and a patterned third metal layer.

[0008] According to one embodiment of the present invention, the third metal layer includes a first section covering the upper surface and sidewall surface of the patterned second metal layer and a second section covering the upper surface of the first metal layer; Etching the first metal layer and the third metal layer to form a patterned first metal layer and a patterned third metal layer includes: A target segment of the third metal layer and the first metal layer located under the target segment are etched by ion beam using a multi-directional etching process to form a patterned first metal layer and a patterned third metal layer; the target segment is at least a portion of the second segment.

[0009] According to one embodiment of the present invention, the distance between the side edge of the patterned third metal layer and the side edge of the groove closest thereto is 5-10 μm; The side edge of the patterned third metal layer is the side edge of the patterned third metal layer in the slow axis direction of the semiconductor laser, and the side edge of the groove is the edge of the notch of the groove.

[0010] According to one embodiment of the present invention, the process of forming a patterned first metal layer and a patterned third metal layer by ion beam etching the first metal layer and the third metal layer using a multi-directional etching process includes: After etching the first metal layer and the third metal layer along a first direction using an ion beam, the first metal layer and the third metal layer are then etched along a second direction to form a patterned first metal layer and a patterned third metal layer; An angle between the first direction and the second direction is greater than 0° and less than 180°.

[0011] According to one embodiment of the present invention, the process of forming a patterned first metal layer and a patterned third metal layer by ion beam etching the first metal layer and the third metal layer using a multi-directional etching process includes: Using an ion beam to etch 1 / 2 of the total thickness of the first metal layer and the third metal layer along a first direction, and then etching 1 / 2 of the total thickness of the first metal layer and the third metal layer along a second direction; The first direction is perpendicular to the second direction.

[0012] According to one embodiment of the present invention, the groove has at least a first inner sidewall and a second inner sidewall, and the angle between the first inner sidewall and the second inner sidewall is α, wherein 0°<α<90°; The first direction is perpendicular to the first inner sidewall, and the second direction is perpendicular to the second inner sidewall.

[0013] According to one embodiment of the present invention, the first metal layer includes at least one of a titanium layer, a platinum layer and a gold layer; The second metal layer comprises at least one of a titanium layer, a platinum layer and a gold layer; The third metal layer includes at least one of a titanium layer, a platinum layer and a gold layer.

[0014] According to one embodiment of the present invention, the thickness of the first metal layer is: 200-400nm; The thickness of the second metal layer is: 2-3 μm; The thickness of the third metal layer is 200-800nm.

[0015] Another aspect of the present invention provides a semiconductor laser, which is prepared using the semiconductor laser preparation method described above; the semiconductor laser includes an epitaxial wafer, a first metal layer, a second metal layer and a third metal layer arranged in sequence from bottom to top.

[0016] Beneficial effects of the present invention: The semiconductor laser preparation method provided by the present invention comprises the following steps: preparing an epitaxial wafer; forming a first metal layer on the epitaxial wafer; forming a patterned second metal layer on the first metal layer; forming a third metal layer on the patterned second metal layer; etching the first metal layer and the third metal layer to form a patterned first metal layer and a patterned third metal layer. In the present invention, two patterning steps are used to form a three-layer patterned metal layer structure. Compared with the existing method of preparing each patterned metal layer, one patterning step is required, which reduces the etching steps and improves the preparation efficiency and device yield of the semiconductor laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the structure of the epitaxial wafer; Figure 2 It is a schematic diagram of the structure after the epitaxial wafer is plated with a dielectric layer; Figure 3 This is a schematic diagram of the structure after the electrode window is opened on the epitaxial wafer; Figure 4It is a schematic diagram of the structure after the first metal layer is electroplated on the epitaxial wafer; Figure 5 is a schematic diagram of the structure after negative photoresist is coated on the first metal layer; Figure 6 A schematic diagram of a structure for forming a patterned second metal layer on a first metal layer; Figure 7 is a schematic diagram of the structure after the third metal layer is electroplated on the second metal layer; Figure 8 A schematic diagram of a structure for forming a patterned first metal layer and a patterned third metal layer; Fig. 9 Schematic diagram of the structure of a semiconductor laser.

[0019] Icon: 1-semiconductor laser; 11-epitaxial wafer; 111-dielectric layer; 112-electrode window; 113-groove; 12-first metal layer; 13-second metal layer; 14-third metal layer; 141-first section; 142-second section; 15-first photoresist layer. DETAILED DESCRIPTION

[0020] In order to more clearly understand the above-mentioned purposes, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0021] In one aspect, an embodiment of the present invention provides a method for preparing a semiconductor laser, comprising the following steps: Figure 1-Figure 3 As shown, prepare epitaxial wafer 11; Figure 4 As shown, a first metal layer 12 is formed on one side of the epitaxial wafer 11; Figure 5-Figure 6 As shown, a patterned second metal layer 13 is formed on the side of the first metal layer 12 away from the epitaxial wafer 11; Figure 7 As shown, a third metal layer 14 is formed on the side of the patterned second metal layer 13 away from the epitaxial wafer 11; Figure 8 As shown, the first metal layer 12 and the third metal layer 14 are etched to form a patterned first metal layer 12 and a patterned third metal layer 14 .

[0022] The semiconductor laser 1 prepared by the semiconductor laser preparation method provided in this embodiment has three patterned metal layers (such as Figure 8As shown, a patterned first metal layer 12, a patterned second metal layer 13, and a patterned third metal layer 14 are sequentially stacked from bottom to top on one side of the epitaxial wafer 11), and the method for preparing a semiconductor laser comprises: electroplating the first metal layer 12 on one side of the epitaxial wafer 11, and then forming a patterned second metal layer 13 through a stripping step, and then electroplating the third metal layer 14, and finally etching the first metal layer 12 and the third metal layer 14 through a patterning step to form a patterned first metal layer 12 and a patterned third metal layer 14. Compared with the existing method of preparing each patterned metal layer by a patterning step, the semiconductor laser preparation method provided by the present application adopts two patterning steps / processes / steps to prepare three patterned metal layers, which reduces the etching steps and improves the preparation efficiency and device yield of the semiconductor laser 1.

[0023] In this embodiment, the epitaxial wafer 11 includes a substrate and an epitaxial layer. The substrate is usually made of GaAs or InP material. The thickness of the substrate is generally greater than 100 μm. The epitaxial layer includes an N-type cladding layer, an N-type waveguide layer, a quantum well active layer, a P-type waveguide layer and a P-type cladding layer which are stacked in sequence along the fast axis direction of the semiconductor laser 1.

[0024] According to one embodiment of the present invention, etching the first metal layer 12 and the third metal layer 14 to form a patterned first metal layer 12 and a patterned third metal layer 14 includes: using a multi-directional etching process to ion beam etch the first metal layer 12 and the third metal layer 14 to form a patterned first metal layer 12 and a patterned third metal layer 14. In the present application, ion beam etching is used when etching the first metal layer 12 and the third metal layer 14. The ion beam etching technology can simultaneously remove the unnecessary parts of the first metal layer 12 and the third metal layer 14 to form the required metal layer pattern (i.e., the patterned first metal layer 12 and the patterned third metal layer 14); and by using ion beam etching, when electroplating the first metal layer 12 and the third metal layer 14, it is not necessary to set a photoresist on the surface of the epitaxial wafer 11 and the second metal layer 13, which can avoid the photoresist from polluting the chamber during the electroplating of the metal layer, and can also avoid the problem of yield loss of the semiconductor laser 1 due to unclean photoresist stripping.

[0025] According to one embodiment of the present invention, Figures 1 to 3 As shown, preparing the epitaxial wafer 11 includes: forming a groove 113 on the epitaxial wafer 11 by etching; plating a dielectric layer 111 on the inner wall of the groove 113 and the upper surface of the epitaxial wafer 11; and forming an electrode window 112 on the dielectric layer 111.

[0026] According to one embodiment of the present invention, Figure 7As shown, the third metal layer 14 includes a first segment 141 covering the upper surface and side wall surface of the patterned second metal layer 13 and a second segment 142 covering the upper surface of the first metal layer 12; etching the first metal layer 12 and the third metal layer 14 to form the patterned first metal layer 12 and the patterned third metal layer 14 includes: using a multi-directional etching process to ion beam etch the target segment of the third metal layer 14 and the first metal layer 12 located at the lower side of the target segment to form the patterned first metal layer 12 and the patterned third metal layer 14; wherein, in this embodiment, using a multi-directional etching process to ion beam etch the target segment of the third metal layer 14 and the first metal layer 12 located at the lower side of the target segment, the etching of the first metal layer 12 and the third metal layer 14 is more complete and the etching effect is better. wherein, the target segment is at least a portion of the second segment, such as Figure 8 and Fig. 9 As shown, the end of the target segment away from the first segment is located between the groove 113 and the first segment; it can be understood that the end of the target segment away from the first segment can also extend to the edge of the notch of the groove 113.

[0027] In an embodiment of the present application, etching the first metal layer 12 and the third metal layer 14 to form a patterned first metal layer 12 and a patterned third metal layer 14 includes: setting a mask on the top of the third metal layer 14; based on the mask, etching and removing the target segment of the third metal layer 14 and the first metal layer 12 covered by the target end to form a patterned first metal layer 12 and a patterned third metal layer 14.

[0028] In this embodiment, the third metal layer 14 is electroplated so that the third metal layer 14 covers the upper surface and side wall surface of the patterned second metal layer 13. At the same time, the third metal layer 14 is also electroplated on the upper surface of the first metal layer 12 that is not covered by the patterned second metal layer 13. The second patterning step is to remove the portion of the first metal layer 12 that is not covered by the patterned second metal layer 13 and the portion of the third metal layer 14 that is not covered by the patterned second metal layer 13 to form a patterned first metal layer 12 and a patterned third metal layer 14.

[0029] In this embodiment, the distance between the side of the patterned third metal layer 14 and the side of the groove closest to it is 5-10 μm; wherein, the side of the patterned third metal layer 14 is the side of the patterned third metal layer 14 in the slow axis direction of the semiconductor laser 1, and the groove side is the edge of the notch of the groove 113. It should be understood that, if Figure 8 and Fig. 9As shown, the side of the patterned third metal layer 14 in the slow axis direction of the semiconductor laser 1 includes two side edges located on the left and right sides of the patterned third metal layer 14, and each side corresponds to a groove 113 closest to it, and the groove 113 also has two groove sides on the left and right sides in the slow axis direction of the semiconductor laser 1; the side of the patterned third metal layer 14 and the side of the groove 113 closest to it are the groove side closest to the side of the patterned third metal layer 14 among the two groove sides of the groove 113 closest to the side of the patterned third metal layer 14. At the same time, it should be understood that in the present application, the side of the patterned first metal layer 12 and the side of the patterned third metal layer 14 on the same side are in the same vertical plane, that is, when the distance between the side of the patterned third metal layer 14 and the side of the groove closest to it is 5-10μm, the distance between the side of the patterned first metal layer 12 and the side of the groove closest to it is also 5-10μm.

[0030] According to one embodiment of the present invention, Figure 5 and Figure 6 As shown, forming a patterned second metal layer 13 on the first metal layer 12 includes: applying a negative photoresist on the upper surface of the first metal layer 12 according to a preset pattern to form a first photoresist layer 15, then electroplating to form the second metal layer 13, and stripping the first photoresist layer 15 to form a patterned second metal layer 13. Figure 5 As shown, the area corresponding to the electrode window 112 is not provided with negative photoresist, and negative photoresist is provided on both sides of the electrode window 112 to form a first photoresist layer 15, and then the second metal layer 13 is electroplated in the electrode window 112 area, and then the first photoresist layer 15 is removed to form a patterned second metal layer 13.

[0031] According to one embodiment of the present invention, the step of using a multi-directional etching process to ion beam etch the first metal layer 12 and the third metal layer 14 to form a patterned first metal layer 12 and a patterned third metal layer 14 includes: etching the first metal layer 12 and the third metal layer 14 along a first direction using an ion beam, and then etching the first metal layer 12 and the third metal layer 14 along a second direction to form a patterned first metal layer 12 and a patterned third metal layer 14; the angle between the first direction and the second direction is greater than 0° and less than 180°. In this embodiment, two directions are used to etch the first metal layer 12 and the third metal layer 14 respectively, and the two directions are not parallel, so that the etching of the part of the first metal layer 12 to be etched and the part of the third metal layer 14 to be etched is more regular and complete, and the etching effect is better.

[0032] Preferably, the step of etching the first metal layer 12 and the third metal layer 14 to form the patterned first metal layer 12 and the patterned third metal layer 14 includes: using an ion beam to etch 1 / 2 of the total thickness of the first metal layer 12 and the third metal layer 14 along a first direction, and then etching 1 / 2 of the total thickness of the first metal layer 12 and the third metal layer 14 along a second direction; wherein the first direction is perpendicular to the second direction. In this embodiment, when etching the first metal layer 12 and the third metal layer 14, an etching effect with a consistent etching rate in the horizontal and vertical directions will be produced when etching is performed based on any direction, that is, when etching the first metal layer 12 and the third metal layer 14 along the first direction, the first metal layer 12 and the third metal layer 14 will be etched simultaneously in the horizontal and vertical directions, and the first metal layer 12 and the third metal layer 14 will be etched at the same rate. Therefore, each time the first metal layer 12 and the third metal layer 14 are etched along each direction, 1 / 2 of the total thickness of the first metal layer 12 and the third metal layer 14 will be etched, while ensuring that the first metal layer 12 and the third metal layer 14 can be completely removed without causing damage to the epitaxial wafer 11, thereby having the beneficial effect of improving the yield of the semiconductor laser 1.

[0033] Among them, Figure 3 As shown, the groove 113 has at least a first inner side wall and a second inner side wall that are inclined and opposite to each other; the first direction is perpendicular to the first inner side wall, and the second direction is perpendicular to the second inner side wall; when etching the first metal layer 12 and the third metal layer 14, at least the first metal layer 12 and the third metal layer 14 in the groove 113 area are etched, and the first metal layer 12 and the third metal layer 14 in the groove 113 area are etched away, and then when actually etching the first metal layer 12 and the third metal layer 14, first etch half of the total thickness of the first metal layer 12 and the third metal layer 14 along the direction perpendicular to the first inner side wall, and then etch half of the total thickness of the first metal layer 12 and the third metal layer 14 along the direction perpendicular to the second inner side wall.

[0034] like Figure 3 As shown, the first inner side wall and the second inner side wall have opposite inclination directions, and the angle between the first inner side wall and the second inner side wall is α, where 0°<α<90°, the first direction and the second direction can intersect in the groove 113 area, and the first metal layer 12 and the third metal layer 14 of the inner side wall of the groove 113 are removed more regularly, preferably as shown in Figures 2 to 9 As shown, the groove 113 is V-shaped or trapezoidal.

[0035] According to one embodiment of the present invention, the first metal layer 12 includes at least one of a titanium layer, a platinum layer and a gold layer; for example, the first metal layer 12 is a titanium layer, the first metal layer 12 is a platinum layer, the first metal layer 12 is a gold layer, the first metal layer 12 is a titanium layer and a platinum layer double-layer structure, the first metal layer 12 is a titanium layer and a gold layer double-layer structure, the first metal layer 12 is a platinum layer and a gold layer double-layer structure, or the first metal layer 12 is a titanium layer, a platinum layer and a gold layer three-layer structure; preferably, the first metal layer 12 is a titanium layer. The thickness of the first metal layer 12 is 200-400nm, preferably 300nm, and the first metal layer 12 is an ohmic contact layer.

[0036] The second metal layer 13 includes at least one of a titanium layer, a platinum layer and a gold layer. Preferably, the second metal layer 13 is a gold layer. The thickness of the second metal layer 13 is 2-3 μm, preferably 2.5 μm. The second metal layer 13 is used as a heat dissipation layer to ensure heat dissipation of the semiconductor laser 1.

[0037] The third metal layer 14 is at least one of a titanium layer, a platinum layer and a gold layer. Preferably, the third metal layer 14 is a double-layer structure of a titanium layer and a gold layer, or the third metal layer 14 is a three-layer structure of a titanium layer, a platinum layer and a gold layer. The thickness of the third metal layer 14 is 200-800nm, preferably 300nm, and the third metal layer 14 is used for packaging matching with the packaging structure.

[0038] The specific steps of the method for preparing a semiconductor laser provided by the present invention are described below with reference to the accompanying drawings.

[0039] The first step is to prepare an epitaxial wafer 11. The epitaxial wafer 11 includes a substrate and an epitaxial layer disposed on the substrate, such as Figures 1 to 3 As shown in FIG. 1 , a plurality of grooves 113 are formed on the epitaxial layer by etching, wherein the grooves 113 are V-shaped or inverted trapezoidal; and then as shown in FIG. Figure 2 As shown, a dielectric layer 111 is plated on the epitaxial layer after the groove 113 is formed; finally, as shown in Figure 3 As shown, an electrode window 112 is formed on the dielectric layer 111 between the two trenches 113 .

[0040] In the second step, the first metal layer 12 covering the epitaxial layer is electroplated on the epitaxial wafer 11 to form a Figure 4 The structure shown.

[0041] The third step is Figure 5 As shown, a negative photoresist is coated on the first metal layer 12 to form a first photoresist layer 15; Figure 5 As shown, a second metal layer 13 is formed on the first metal layer 12 except for the photoresist covered area by lift-off. Figure 6 As shown, the second metal layer 13 covers the electrode window 112 .

[0042] The fourth step is Figure 7 As shown, a third metal layer 14 is electroplated, and the third metal layer 14 covers the outer wall surface of the second metal layer 13 and the upper surface of the first metal layer 12 .

[0043] The fifth step is to set a mask on the top of the third metal layer 14, first use an ion beam to etch 1 / 2 of the total thickness of the first metal layer 12 and the third metal layer 14 along the first direction, and then use an ion beam to etch 1 / 2 of the total thickness of the first metal layer 12 and the third metal layer 14 along the second direction.

[0044] Step 6: Figure 8 and Fig. 9 As shown, the mask disposed on the upper side of the third metal layer 14 is removed, thereby obtaining the semiconductor laser 1 having the patterned first metal layer 12 , the patterned second metal layer 13 and the patterned third metal layer 14 .

[0045] Another embodiment of the present invention further provides a semiconductor laser 1, which is prepared by the semiconductor laser preparation method described in any of the above embodiments. Figure 8 As shown, the semiconductor laser 1 includes an epitaxial wafer 11, a first metal layer 12, a second metal layer 13 and a third metal layer 14 which are arranged in sequence from bottom to top.

[0046] In an embodiment of the present application, the semiconductor laser 1 includes: an epitaxial wafer 11; a groove 113 formed in the epitaxial wafer 11, and an electrode window 112; a patterned first metal layer 12, a patterned second metal layer 13 and a patterned third metal layer 14 formed on one side of the epitaxial wafer 11 and stacked in sequence; wherein the patterned second metal layer 13 is at least arranged on the top of the electrode window 112, the patterned second metal layer 13 is at least coated on the outer wall surface of the patterned second metal layer 13, and the side edge of the patterned first metal layer 12 and the side edge of the patterned third metal layer 14 are at least located in the same vertical plane. The structure of the patterned first metal layer 12, the patterned second metal layer 13 and the patterned third metal layer 14 is as shown in FIG. Figure 8 or Fig. 9 shown.

[0047] In the embodiments of the present application, Fig. 9 The structure shown is a structure in which two semiconductor lasers 1 are spliced ​​together; in the actual production process, the semiconductor laser 1 is usually based on Fig. 9 The structure shown is obtained by peeling.

[0048] In the description of the present invention, it should be noted that the terms "upper", "lower", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0049] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the inside of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a semiconductor laser, characterized in that: The following steps are involved: preparing an epitaxial wafer (11); forming a first metal layer (12) on the epitaxial wafer (11); forming a patterned second metal layer (13) on the first metal layer (12); forming a third metal layer (14) on the patterned second metal layer (13); The first metal layer (12) and the third metal layer (14) are etched to form a patterned first metal layer (12) and a patterned third metal layer (14).

2. The method for preparing a semiconductor laser according to claim 1, characterized in that: The preparation of the epitaxial wafer (11) comprises: Forming a groove (113) on the epitaxial wafer (11); Plating a dielectric layer (111) on the inner wall of the groove (113) and the upper surface of the epitaxial wafer (11); An electrode window (112) is formed on the dielectric layer (111).

3. The method for preparing a semiconductor laser according to claim 2, characterized in that: Forming a patterned second metal layer (13) on a first metal layer (12) comprises: Applying a negative photoresist on the upper surface of the first metal layer (12) according to a preset pattern, electroplating to form a second metal layer (13), and stripping the negative photoresist to form a patterned second metal layer (13); Wherein, the patterned second metal layer (13) at least covers the electrode window (112).

4. The method for preparing a semiconductor laser according to claim 3, characterized in that: The etching of the first metal layer (12) and the third metal layer (14) to form a patterned first metal layer (12) and a patterned third metal layer (14) comprises: A multi-directional etching process is adopted to form a patterned first metal layer (12) and a patterned third metal layer (14) by ion beam etching the first metal layer (12) and the third metal layer (14).

5. The method for preparing a semiconductor laser according to claim 4, characterized in that: The third metal layer (14) comprises a first section (141) covering the upper surface and side wall surface of the patterned second metal layer (13) and a second section (142) covering the upper surface of the first metal layer (12); Etching the first metal layer (12) and the third metal layer (14) to form a patterned first metal layer (12) and a patterned third metal layer (14) comprises: A multi-directional etching process is adopted to ion beam etch a target segment of the third metal layer (14) and a first metal layer (12) located below the target segment to form a patterned first metal layer (12) and a patterned third metal layer (14); the target segment is at least a portion of the second segment (142).

6. The method for preparing a semiconductor laser according to claim 5, characterized in that: The distance between the side edge of the patterned third metal layer (14) and the side edge of the groove closest to it is 5-10 um; The side edge of the patterned third metal layer (14) is the side edge of the patterned third metal layer (14) in the slow axis direction of the semiconductor laser (1), and the groove side edge is the edge of the groove opening of the groove (113).

7. The method for preparing a semiconductor laser according to claim 4, characterized in that: The method adopts a multi-directional etching process to ion beam etch the first metal layer (12) and the third metal layer (14) to form a patterned first metal layer (12) and a patterned third metal layer (14), comprising: After etching the first metal layer (12) and the third metal layer (14) along a first direction using an ion beam, the first metal layer (12) and the third metal layer (14) are then etched along a second direction to form a patterned first metal layer (12) and a patterned third metal layer (14); An angle between the first direction and the second direction is greater than 0° and less than 180°.

8. The method for preparing a semiconductor laser according to claim 7, characterized in that: The method adopts a multi-directional etching process to ion beam etch the first metal layer (12) and the third metal layer (14) to form a patterned first metal layer (12) and a patterned third metal layer (14), comprising: Using an ion beam to etch 1 / 2 of the total thickness of the first metal layer (12) and the third metal layer (14) along a first direction, and then etching 1 / 2 of the total thickness of the first metal layer (12) and the third metal layer (14) along a second direction; The first direction is perpendicular to the second direction.

9. The method for preparing a semiconductor laser according to claim 7, characterized in that: The groove (113) has at least a first inner side wall and a second inner side wall, and the angle between the first inner side wall and the second inner side wall is α, wherein 0°<α<90°; The first direction is perpendicular to the first inner sidewall, and the second direction is perpendicular to the second inner sidewall.

10. The method for preparing a semiconductor laser according to any one of claims 1 to 9, characterized in that: The first metal layer (12) comprises at least one of a titanium layer, a platinum layer and a gold layer; The second metal layer (13) comprises at least one of a titanium layer, a platinum layer and a gold layer; The third metal layer (14) comprises at least one of a titanium layer, a platinum layer and a gold layer.

11. The method for preparing a semiconductor laser according to any one of claims 1 to 9, characterized in that: The thickness of the first metal layer (12) is: 200-400nm; The thickness of the second metal layer (13) is: 2-3 μm; The thickness of the third metal layer (14) is 200-800 nm.

12. A semiconductor laser, characterized in that: The semiconductor laser is prepared using the method for preparing a semiconductor laser as claimed in any one of claims 1 to 11; the semiconductor laser comprises an epitaxial wafer (11), a first metal layer (12), a second metal layer (13) and a third metal layer (14) arranged in sequence from bottom to top.

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