Semiconductor laser manufacturing method and semiconductor laser

Abstract

The present invention discloses a semiconductor laser manufacturing method and a semiconductor laser, and relates to the field of semiconductor technology. The semiconductor laser manufacturing method comprises: providing a substrate with a ridge strip, the ridge strip comprises a plurality of strip segments with different widths; depositing a dielectric film on the substrate; forming a photoresist material layer on the dielectric film; providing a mask and placing it above the photoresist material layer, the light-transmitting area of ​​the mask comprises a plurality of light-transmitting segments respectively corresponding to the plurality of strip segments; exposing the photoresist material layer through the mask; developing the exposed photoresist material layer to form a reflow groove, the reflow groove comprises a plurality of groove segments corresponding to each strip segment, and the groove sidewalls of the plurality of groove segments have the same gap width as the corresponding strip segments. The semiconductor laser manufacturing method provided by the present invention can prepare a semiconductor laser with higher electrical characteristics and reliability.

Description

Technical Field

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

[0002] In order to meet the requirements of power, single-mode characteristics and reliability, the ridge stripe of a single-mode high-power semiconductor laser usually needs to be designed as a structure with varying width, that is, the width dimensions of multiple positions in the length direction of the ridge stripe are different.

[0003] When this type of semiconductor laser uses the reflow process to prepare the electrode window, the reflow process parameters are fixed, and the reflow height of the photoresist is inconsistent at positions with different ridge widths. As a result, the insulating layer on the surfaces of both sides of the ridge cannot be accurately covered. As a result, when the insulating layer on the top of the ridge is subsequently etched away, the insulating layer on the surfaces of both sides of the ridge will also be partially etched, seriously affecting the electrical characteristics and reliability of the product. Summary of the invention

[0004] The object of the present invention is to provide a method for manufacturing a semiconductor laser, which can produce a semiconductor laser with higher electrical characteristics and reliability.

[0005] The embodiment of the present invention provides a technical solution:

[0006] A method for manufacturing a semiconductor laser, comprising:

[0007] Providing a substrate having a ridge strip, wherein the ridge strip comprises a plurality of strip segments having different widths;

[0008] depositing a dielectric film on the substrate;

[0009] forming a photoresist material layer on the dielectric film;

[0010] Providing a mask and placing it above the photoresist material layer, wherein the light-transmitting area of ​​the mask includes a plurality of light-transmitting segments respectively corresponding to the plurality of strip segments;

[0011] exposing the photoresist material layer through the mask;

[0012] The exposed photoresist material layer is developed to form a reflow groove, wherein the reflow groove comprises a plurality of groove sections corresponding to each of the strip sections, and the gap widths between the groove side walls of the plurality of groove sections and the corresponding strip sections are equal.

[0013] In an optional embodiment, after the step of developing the exposed photoresist material layer to form a reflow groove, the semiconductor laser manufacturing method further includes:

[0014] A reflow process is adopted to make the photoresist material layer reflow to fill the plurality of groove sections of the reflow groove so as to cover the dielectric film on the side surface of the ridge strip.

[0015] In an optional embodiment, after the step of using a reflow process to reflow the photoresist material layer to fill the plurality of groove segments of the reflow groove, the semiconductor laser manufacturing method further includes:

[0016] removing the portion of the dielectric film covering the top of the ridge strip to obtain an electrode contact window;

[0017] A conductive metal layer is formed in the electrode contact window.

[0018] In an optional embodiment, the ridge includes a main body and a cap body arranged at the top of the main body, and the cap body has constraint side walls on both sides in the width direction that are inclined relative to the vertical direction, and the constraint side walls are connected to the side walls of the main body adjacent to them to form a concave angle.

[0019] In an optional embodiment, the step of providing a substrate having ridges comprises:

[0020] Providing a substrate, and growing a P-type layer structure on the substrate;

[0021] Growing an AlGaAs epitaxial layer on the P-type layer structure;

[0022] Growing a GaAs epitaxial layer on the AlGaAs epitaxial layer;

[0023] Processing the GaAs epitaxial layer and the AlGaAs epitaxial layer by photolithography and etching to obtain a ridge structure;

[0024] The ridge structure is etched with a mixed solution consisting of H2SO4, H2O2 and H2O, so that the GaAs epitaxial layer is formed into the cap body and the AlGaAs epitaxial layer is formed into the main body, thereby obtaining the ridge stripe.

[0025] In an optional embodiment, the top end of the cap body has a main top wall and inclined top walls located on both sides of the main top wall, and either end of the main top wall in the width direction is connected to the constraining side wall through the inclined top wall, and the inclined top wall and the adjacent constraining side wall form a positive angle.

[0026] In an optional embodiment, the thickness of the cap body is between 200 nm and 300 nm, and / or,

[0027] The inner angle is between 120° and 130°, and / or

[0028] The positive angle is between 15° and 20°.

[0029] In an optional embodiment, the gap width between the groove side walls of the plurality of groove segments and the respective corresponding strip segments is between 5 μm and 7 μm.

[0030] In an optional embodiment, the step of forming a photoresist material layer on the dielectric film includes:

[0031] The photoresist is coated on the dielectric film by a spin coating process to form the photoresist material layer, wherein the distance between the top of the ridge stripe and the upper surface of the photoresist material layer is between 0.5 μm and 1 μm.

[0032] In an optional embodiment, after the exposed photoresist material layer is developed, the distance between the top of the ridge and the bottom wall of the reflow groove is greater than 0.5 μm.

[0033] In an optional embodiment, after the step of developing the exposed photoresist material layer, the semiconductor laser manufacturing method further includes:

[0034] performing surface treatment on the photoresist material layer to reduce the surface tension of the photoresist material layer, and / or,

[0035] Surface treatment is performed on the portions of the dielectric film on both side surfaces in the width direction of the ridge stripe to improve surface polarity.

[0036] In an optional embodiment, the plurality of strip segments include a wide strip segment, a gradient segment and a narrow strip segment connected in sequence;

[0037] The plurality of light-transmitting sections include a wide strip area corresponding to the wide strip section, a gradual change area corresponding to the gradual change section, and a narrow strip area corresponding to the narrow strip section;

[0038] The plurality of slot sections include a wide slot section for accommodating the wide strip section, a gradual slot section for accommodating the gradual section, and a narrow slot section for accommodating the narrow strip section.

[0039] An embodiment of the present invention further provides a semiconductor laser, which is manufactured based on the aforementioned semiconductor laser manufacturing method.

[0040] Compared with the prior art, the semiconductor laser manufacturing method provided by the embodiment of the present invention has different window sizes at positions with different ridge widths, so that groove structures with different widths are formed correspondingly after the photoresist is developed, and the width of the reflow gap at positions with different widths is ensured to be consistent, thereby ensuring the photoresist reflow height is consistent. By adjusting the reflow parameters, the photoresist can be accurately reflowed to the insulating layer covering the surfaces on both sides of the ridge, ensuring the accuracy of the electrode window, and improving the electrical characteristics and reliability of the product. Therefore, the beneficial effects of the semiconductor laser manufacturing method provided by the present invention include: a semiconductor laser with higher electrical characteristics and reliability can be prepared. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative work.

[0042] Figure 1 A flowchart of a method for manufacturing a semiconductor laser provided by an embodiment of the present invention;

[0043] Figure 2 for Figure 1 A top view of the substrate provided in step S101;

[0044] Figure 3 for Figure 2 Schematic diagram of the structure of the narrow strip segment of the middle ridge;

[0045] Figure 4 for Figure 2 Schematic diagram of the structure of the wide strip section of the middle ridge;

[0046] Figure 5 A schematic diagram of the angle marking of the narrow strip segment;

[0047] Figure 6 for Figure 1 A flowchart of a sub-step of step S101;

[0048] Figure 7 A schematic diagram of the structure of the ridge structure prepared in sub-step S1014;

[0049] Figure 8 is a schematic diagram of the structure of the narrow strip segment of the ridge strip after step S102;

[0050] Fig. 9 is a schematic diagram of the structure of the narrow strip segment of the ridge strip after step S103;

[0051] Fig.10 is a schematic diagram of the structure of the mask;

[0052] Fig.11 is a top view of the substrate after step S106;

[0053] Fig.12 for Fig.11 Schematic diagram of the structure of the middle narrow strip segment;

[0054] Fig.13 for Fig.11 Schematic diagram of the structure of the medium width strip segment;

[0055] Fig.14 is a schematic diagram of the structure of the narrow strip segment of the ridge strip after step S109;

[0056] Fig.15 Schematic diagram of the structure of the narrow strip segment of the ridge strip after step S110.

[0057] Icons: 100-substrate; 110-ridge; 111-wide strip segment; 112-gradient segment; 113-narrow strip segment; 114-main body; 115-cap body; 1151-constrained side wall; 1152-front top wall; 1153-slanted top wall; 116-ridge structure; 119-shoulder; 120-dielectric film; 121-electrode contact window; 130-photoresist material layer; 131-wide groove segment; 132-gradient groove segment; 133-narrow groove segment; 140-mask; 141-wide strip area; 142-gradient area; 143-narrow strip area. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0059] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0061] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0062] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0063] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" 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 an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0065] Example

[0066] See also Figure 1 , Figure 1 FIG. 1 is a flowchart of a method for manufacturing a semiconductor laser provided in this embodiment. The method for manufacturing a semiconductor laser provided in this embodiment may include:

[0067] Step S101 , providing a substrate 100 having a ridge 110 , wherein the ridge 110 includes a plurality of segments with different widths.

[0068] In this embodiment, the ridge 110 has a wide segment 111 , a gradual segment 112 , and a narrow segment 113 which are sequentially connected in the length direction thereof.

[0069] Please refer to Figure 2 , Figure 2 FIG. 1 is a top view of the substrate 100 provided in step S101 .

[0070] It can be understood that the width dimension of the wide segment 111 is greater than the width dimension of the narrow segment 113. The wide segment 111 is connected to the narrow segment 113 through the gradient segment 112. The width dimension of the gradient segment 112 gradually decreases from one end connected to the wide segment 111 to the other end connected to the narrow segment 113.

[0071] Depend on Figure 2 As shown, the width dimension of the narrow strip segment 113 is d1, the width dimension of the wide strip segment 111 is d2, and the difference between d2 and d1 is between 2 μm and 5 μm. In fact, in this embodiment, d1 is 5 μm, and d2 is 9 μm.

[0072] Please refer to Figure 3 and Figure 4 , Figure 3 FIG. 1 is a schematic diagram showing the structure of the narrow strip segment 113 of the ridge strip 110. Figure 4 FIG. 1 is a schematic structural diagram of a wide strip segment 111 of a ridge strip 110 .

[0073] In this embodiment, the ridge 110 includes a main body 114 and a cap body 115 arranged at the top of the main body 114. The cap body 115 has constraint side walls 1151 inclined relative to the vertical direction on both sides in the width direction. The two constraint side walls 1151 are respectively connected to the opposite side walls of the main body 114 to form a concave angle.

[0074] It can be understood that the “width direction” in this embodiment refers to a direction parallel to the slow axis direction of the semiconductor laser.

[0075] The top of the cap body 115 has a main top wall 1152 and two inclined top walls 1153 . The two ends of the main top wall 1152 in the width direction are respectively connected to the two constraining side walls 1151 through the two inclined top walls 1153 . The two inclined top walls 1153 and the two constraining side walls 1151 form two positive angles.

[0076] In fact, the width dimension d1 of the narrow strip segment 113 in this embodiment refers to the width of the cap body 115 of the narrow strip segment 113, that is, the distance between the two positive corners at both ends of the cap body 115 of the narrow strip segment 113. Similarly, the width dimension d2 of the wide strip segment 111 refers to the width of the cap body 115 of the wide strip segment 111, that is, the distance between the two positive corners at both ends of the cap body 115 of the wide strip segment 111.

[0077] Please refer to Figure 5 , Figure 5 The narrow strip segment 113 of the ridge strip 110 is shown as an angled schematic diagram.

[0078] In fact, for the narrow strip segment 113 and the wide strip segment 111, except for the width of the cap body 115, other dimensions are basically the same. Figure 5 In the figure, the angle θ is the negative angle formed by the connection between the constraint side wall 1151 and the side wall of the main body 114 , and the angle α is the positive angle formed by the inclined top wall 1153 and the constraint side wall 1151 .

[0079] In this embodiment, as a preference, the thickness of the cap body 115 is between 200 nm and 300 nm, and the thickness of the cap body 115 refers to the vertical dimension of the cap body 115. The inner angle is between 120° and 130°, and the outer angle is between 15° and 20°.

[0080] Figure 5 In the figure, dimension L represents the protruding dimension of the constrained side wall 1151 relative to the side wall of the main body 114 in the width direction. It can be understood that to ensure that the constrained side wall 1151 plays an effective constraining role in the photoresist reflow, L must be greater than the minimum reflow radius of the photoresist. The minimum reflow radius of the photoresist depends on the characteristics of the photoresist itself and the reflow temperature.

[0081] Please refer to Figure 6 , Figure 6 The flowchart shown is a sub-step of step S101. Step S101 may include the following sub-steps:

[0082] Sub-step S1011, providing a substrate, and growing a P-type layer structure on the substrate.

[0083] Sub-step S1012, growing an AlGaAs epitaxial layer on the P-type layer structure.

[0084] Sub-step S1013, growing a GaAs epitaxial layer on the AlGaAs epitaxial layer.

[0085] Sub-step S1014 , processing the GaAs epitaxial layer and the AlGaAs epitaxial layer by photolithography and etching to obtain a ridge structure 116 .

[0086] In sub-step S1015 , a mixed solution of H 2 SO 4 , H 2 O 2 and H 2 O is used to etch the ridge structure 116 , so that the GaAs epitaxial layer is formed into a cap body 115 and the AlGaAs epitaxial layer is formed into a main body 114 , thereby obtaining a ridge stripe 110 .

[0087] It is understandable that after sub-step S1015, it is necessary to remove the ridge stripe 110 etching mask photoresist. In this embodiment, the substrate 100 after the ridge stripe 110 is formed is placed in a 70°C NMP solution for 30 minutes, then soaked in an IPA solution for 30 minutes, and finally rinsed with ionized water and then dried with nitrogen.

[0088] It can be understood that the P-type layer structure may include a layered structure such as a confinement layer and an active layer that are sequentially grown on a substrate.

[0089] Please refer to Figure 7 , Figure 7 FIG. 1 is a schematic structural diagram of the ridge structure 116 prepared in sub-step S1014 .

[0090] The ridge structure 116 is actually a regular trapezoidal structure. It is understandable that after sub-step S1014 , the sizes of the portion of the ridge structure 116 corresponding to the wide segment 111 , the portion corresponding to the gradient segment 112 , and the portion corresponding to the narrow segment 113 are different.

[0091] In getting Figure 7 After the ridge structure 116 is formed, the assembly structure is etched in sub-step S1015 to obtain the ridge strip 110. Specifically, the ridge structure 116 is etched with a mixture of H2SO4, H2O2 and H2O. The etching time is 5 minutes and the depth of the ridge strip 110 is 1.5 μm. Affected by the lattice of the GaAs epitaxial layer and the AlGaAs epitaxial layer, the ridge strip 110 is etched in the range of

[011] and [01 ] Positive trapezoidal and inverted trapezoidal morphologies are formed in two crystal directions.

[0092] This morphology forms an angle θ, which is theoretically 125°16′, but in practice, due to the influence of stress or dislocations of epitaxial growth, the angle will change slightly, generally between 120° and 130°.

[0093] In other words, after etching, the GaAs epitaxial layer is formed into the cap body 115, and the AlGaAs epitaxial layer is formed into the main body 114. The constrained side wall 1151, the inclined top wall 1153 of the cap body 115, and the positive angle formed between the two are also etched and formed under the influence of their lattices. Similarly, the regular trapezoidal structure of the main body 114 is also etched.

[0094] Please continue reading Figure 1 The semiconductor laser manufacturing method provided in this embodiment may further include:

[0095] Step S102 , depositing a dielectric film 120 on the substrate 100 .

[0096] Please refer to Figure 8 , Figure 8 FIG. 1 is a schematic structural diagram of the narrow strip segment 113 of the ridge strip 110 after step S102 .

[0097] In this embodiment, the dielectric film 120 is a SiNx film with a thickness of 400 nm.

[0098] It can be understood that the narrow stripe segment 113 , the gradient segment 112 , the wide stripe segment 111 of the ridge stripe 110 , and the shoulder 119 on the surface of the substrate 100 except the ridge stripe 110 are all covered by the SiNx film.

[0099] Please continue reading Figure 1 The semiconductor laser manufacturing method provided in this embodiment may further include:

[0100] Step S103 , forming a photoresist material layer 130 on the dielectric film 120 .

[0101] Please refer to Fig. 9 , Fig. 9 FIG. 1 is a schematic structural diagram of the narrow strip segment 113 of the ridge strip 110 after step S103 .

[0102] In this embodiment, a photoresist is coated on the dielectric film 120 by a spin coating process to form the photoresist material layer 130. Specifically, the 5312 photoresist is spin coated at a rotation speed of 1500 rpm and a spin coating thickness of 2 μm to 2.5 μm.

[0103] Please continue reading Figure 1 The semiconductor laser manufacturing method provided in this embodiment may further include:

[0104] Step S104 , providing a mask 140 and placing it on the photoresist material layer 130 , wherein the light-transmitting area of ​​the mask 140 includes a plurality of light-transmitting segments respectively corresponding to the plurality of strip segments.

[0105] Corresponding to the multiple stripe segments of the ridge stripe 110 , the light-transmitting region of the mask plate 140 has a wide stripe region 141 , a gradient region 142 , and a narrow stripe region 143 which are sequentially connected in the length direction thereof.

[0106] Please refer to Fig.10 , Fig.10 FIG. 1 is a schematic structural diagram of the mask 140 .

[0107] like Fig.10 As shown, the width dimension of the narrow stripe region 143 in the light-transmitting area of ​​the mask 140 is d5, and the width dimension of the wide stripe region 141 is d6. After the mask 140 is arranged, the projection of the wide stripe region 141 on the substrate 100 encloses the wide stripe segment 111 of the ridge 110, the projection of the gradient region 142 on the substrate 100 encloses the gradient segment 112 of the ridge 110, and the projection of the narrow stripe region 143 on the substrate 100 encloses the narrow stripe segment 113 of the ridge 110.

[0108] Moreover, the axis of the light-transmitting area is aligned with the axis of the ridge 110 in the vertical direction. In this embodiment, d5 is 10 μm and d6 is 14 μm. Therefore, in the width direction, the distance between any edge of the wide stripe area 141 and the wide stripe segment 111 is 5 μm, the distance between any edge of the narrow stripe area 143 and the narrow stripe segment 113 is 5 μm, and the distance between any edge of the gradient area 142 and the gradient segment 112 is also 5 μm.

[0109] Please continue reading Figure 1 The semiconductor laser manufacturing method provided in this embodiment may further include:

[0110] Step S105 , exposing the photoresist material layer 130 through the mask 140 .

[0111] In this embodiment, a SUSS MA6 photolithography machine is used for exposure, and the exposure metering is 45 mJ.

[0112] Step S106 , developing the exposed photoresist material layer 130 to form a reflow groove, wherein the reflow groove includes a plurality of groove segments corresponding to the plurality of strip segments, and the width of the gaps between the groove sidewalls of the plurality of groove segments and the corresponding strip segments are equal.

[0113] The multiple groove sections of the reflow groove include a wide groove section 131 corresponding to the wide strip area 141, a gradient groove section 132 corresponding to the gradient area 142, and a narrow groove section 133 corresponding to the narrow strip area 143, and the wide strip section 111 is accommodated in the wide groove section 131, the gradient section 112 is accommodated in the gradient groove section 132, and the narrow strip section 113 is accommodated in the narrow groove section 133.

[0114] Please refer to Fig.11 , Fig.12 and Fig.13 , Fig.11 FIG. 1 is a top view of the substrate 100 after step S106. Fig.12 FIG. 1 is a schematic diagram showing the structure of the narrow strip segment 113 of the ridge strip 110 after step S106. Fig.13 FIG. 1 is a schematic structural diagram of the wide strip segment 111 of the ridge strip 110 after step S106 .

[0115] In this embodiment, the developer is TMAH and the developing time is 50 seconds. Then, a pre-baking is performed at a temperature of 120° C. and the duration is 120 seconds.

[0116] In fact, the distance between the top of the ridge 110 and the upper surface of the photoresist layer 130 is between 0.5 μm and 1 μm. Since the thickness of the dielectric film 120 is relatively small, it can be approximately considered that H1 is between 0.5 μm and 1 μm.

[0117] In this embodiment, the wide groove section 131, the gradient groove section 132 and the narrow groove section 133 have the same groove bottom wall. After the exposed photoresist material layer 130 is developed, in order to ensure the subsequent RIE etching barrier, the distance between the top of the ridge stripe 110 and the groove bottom wall is preferably greater than 0.5 μm. In addition, d4 in the figure is approximately 0.5 μm.

[0118] H2 represents the distance between the top of the ridge 110 and the bottom surface of the photoresist layer 130 , and can be considered to be approximately equal to the distance between the top surface of the dielectric film 120 and the bottom surface of the photoresist layer 130 , that is, H2 is greater than 0.5 μm.

[0119] Due to the structural design of the mask 140 and the same exposure and development parameters, after the wide groove segment 131, the gradient groove segment 132 and the narrow groove segment 133 are formed in the photoresist material layer 130 through steps S105 and S106, the gap widths between the two groove side walls of the wide groove segment 131 and the opposite sides of the wide strip segment 111 are equal, and are equal to the gap width between any groove side wall of the gradient groove segment 132 and the gradient segment 112, and are also equal to the gap width between any groove side wall of the narrow groove segment 133 and the narrow strip segment 113.

[0120] In other words, the width of the reflow gaps of the wide slot section 131, the gradient slot section 132 and the narrow slot section 133 is the same, that is, d3. Similarly, d3 actually refers to the distance between the positive corner of the cap body 115 and the corresponding slot side wall, and in this embodiment, it can also be considered as the distance between the positive corner surface dielectric film 120 and the corresponding slot side wall, and d3 is 5 μm.

[0121] It should be noted that in other embodiments where the ridge 110 is a regular trapezoidal structure, the reflow gap width refers to the distance between the top of the side wall of the regular trapezoidal structure and the corresponding groove side wall.

[0122] Please continue reading Figure 1 The semiconductor laser manufacturing method provided in this embodiment may further include:

[0123] Step S107 , performing surface treatment on the photoresist material layer 130 to reduce the surface tension of the photoresist material layer 130 .

[0124] In step S107 of this embodiment, a layer of surfactant solution may be sprayed or coated on the surface of the photoresist layer 130 to reduce the surface tension of the photoresist layer 130, thereby promoting the flow of the photoresist. Oxidation groups may also be introduced on the surface of the photoresist layer 130 to reduce its surface tension.

[0125] Step S108 , performing surface treatment on the portions of the dielectric film 120 on both sides of the ridge stripe 110 in the width direction to improve the surface polarity.

[0126] In step S108 of this embodiment, N plasma treatment is applied to the dielectric film 120 exposed by development to introduce nitrogen groups, thereby increasing the surface polarity, enhancing the adhesion of the photoresist, and reducing the fluidity of the photoresist on the surface of the dielectric film 120, so as to facilitate precise control of the climbing height of the photoresist.

[0127] In step S109 , a reflow process is used to reflow the photoresist material layer 130 to fill multiple groove sections of the reflow groove to cover the portions of the dielectric film 120 on both side surfaces in the width direction of the ridge stripe 110 .

[0128] The photoresist material layer 130 is reflowed by a reflow process to fill the wide groove section 131 , the gradient groove section 132 and the narrow groove section 133 , so as to cover the portions of the dielectric film 120 on both side surfaces in the width direction of the ridge stripe 110 .

[0129] Please refer to Fig.14 , Fig.14 FIG. 1 is a schematic diagram showing the structure of the narrow strip segment 113 of the ridge strip 110 after step S109 .

[0130] It can be understood that since the reflow gap widths at positions of different width sizes on the ridge 110 are consistent, the photoresist reflow height is guaranteed to be consistent. By adjusting the reflow parameters, the photoresist can be accurately reflowed to the insulating layer covering the surfaces on both sides of the ridge 110, that is, accurately covering the two positive corner top positions of the cap body 115 of the ridge 110, thereby ensuring the accuracy of the electrode window and improving the electrical characteristics and reliability of the product.

[0131] In this embodiment, the baking temperature in the reflow process is 150° C. and the duration is 4 minutes. After the process is completed, microscopic inspection and step profiler measurement are required to further ensure the climbing effect of the photoresist.

[0132] It should be noted that due to the setting of the constraint side wall 1151 on the cap body 115 in this embodiment, a certain degree of downward constraint force can be applied to the photoresist during the reflow process, ensuring that the photoresist climbs smoothly on the constraint side wall 1151 and avoiding sudden changes in the climbing stroke, thereby enabling fine control of the reflow height of the photoresist, that is, accurately controlling the photoresist to climb to the positive corner positions on both sides.

[0133] Please continue reading Figure 1 The semiconductor laser manufacturing method provided in this embodiment may further include:

[0134] Step S110 , removing the portion of the dielectric film 120 covering the top of the ridge stripe 110 to obtain an electrode contact window 121 .

[0135] Please refer to Fig.15 , Fig.15 FIG. 1 is a schematic structural diagram of the narrow strip segment 113 of the ridge strip 110 after step S110 .

[0136] In step S110 of this embodiment, PT-RIE is used to etch the portion of the SiNx film layer exposed by the photoresist material layer 130, using 20 sccm of SF6 gas and 5 sccm of oxygen, and the etching process lasts for 5 minutes.

[0137] In fact, after etching is completed, the substrate 100 is immersed in a 70° C. NMP solution for 30 minutes, and then immersed in an IPA solution for 30 minutes, and finally rinsed and dried to obtain the electrode contact window 121 .

[0138] Please continue reading Figure 1 The semiconductor laser manufacturing method provided in this embodiment may further include:

[0139] Step S111 , forming a conductive metal layer in the electrode contact window 121 .

[0140] After the electrode contact window 121 is formed, metal deposition is performed on the electrode contact window 121 to form a conductive metal layer.

[0141] In summary, the semiconductor laser manufacturing method provided in this embodiment can produce a semiconductor laser with higher electrical characteristics and reliability.

[0142] In addition, this embodiment also provides a semiconductor laser, which is manufactured based on the aforementioned semiconductor laser manufacturing method.

[0143] Benefiting from the aforementioned semiconductor laser manufacturing method, the ridge strip 110 of the semiconductor laser has a special structure, specifically including a main body 114 and a cap body 115 arranged at the top of the main body 114. The cap body 115 has constraint side walls 1151 inclined relative to the vertical direction on both sides in the width direction. The constraint side walls 1151 are connected to the side walls of the main body 114 adjacent to it to form a concave angle. The constraint side walls 1151 play an effective constraint role on the photoresist reflow, thereby ensuring the reflow accuracy of the photoresist.

[0144] In addition, the top end of the cap body 115 has a main top wall 1152 and inclined top walls 1153 located on both sides of the main top wall 1152. Either end of the main top wall 1152 in the width direction is connected to the constraining side wall 1151 through the inclined top wall 1153, and the inclined top wall 1153 and the adjacent constraining side wall 1151 form a positive angle.

[0145] Benefiting from the aforementioned semiconductor laser manufacturing method, the semiconductor laser provided in this embodiment has the characteristics of higher electrical characteristics and reliability. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for manufacturing a semiconductor laser, characterized in that: include: Providing a substrate (100) having a ridge strip (110), wherein the ridge strip (110) comprises a plurality of strip segments with different widths; Depositing a dielectric film (120) on the substrate (100); forming a photoresist material layer (130) on the dielectric film (120); Providing a mask (140) and placing it above the photoresist material layer (130), wherein the light-transmitting area of ​​the mask (140) comprises a plurality of light-transmitting segments respectively corresponding to the plurality of strip segments; Exposing the photoresist material layer (130) through the mask (140); Performing a development process on the exposed photoresist material layer (130) to form a reflow groove, wherein the reflow groove comprises a plurality of groove sections corresponding to each of the strip sections, and the gap widths between the groove side walls of the plurality of groove sections and the corresponding strip sections are equal; After the step of developing the exposed photoresist material layer (130) to form a reflow groove, the semiconductor laser manufacturing method further comprises: Using a reflow process to make the photoresist material layer (130) reflow to fill the plurality of groove sections of the reflow groove, so as to cover the dielectric film (120) on the side of the ridge strip (110); After the step of using a reflow process to make the photoresist material layer (130) reflow to fill the plurality of groove sections of the reflow groove, the semiconductor laser manufacturing method further comprises: Removing the portion of the dielectric film (120) covering the top of the ridge strip (110) to obtain an electrode contact window (121); A conductive metal layer is formed in the electrode contact window (121).

2. The method for manufacturing a semiconductor laser according to claim 1, characterized in that: The ridge (110) comprises a main body (114) and a cap body (115) arranged at the top end of the main body (114); both sides of the cap body (115) in the width direction have constraining side walls (1151) arranged obliquely relative to the vertical direction; the constraining side walls (1151) are connected to the side walls of the main body (114) adjacent thereto to form a concave angle.

3. The method for manufacturing a semiconductor laser according to claim 2, characterized in that: The step of providing a substrate (100) having ridges (110) comprises: Providing a substrate, and growing a P-type layer structure on the substrate; Growing an AlGaAs epitaxial layer on the P-type layer structure; Growing a GaAs epitaxial layer on the AlGaAs epitaxial layer; Processing the GaAs epitaxial layer and the AlGaAs epitaxial layer using a photolithography process and an etching process to obtain a ridge structure (116); The ridge structure (116) is etched using a mixed solution consisting of H2SO4, H2O2 and H2O, so that the GaAs epitaxial layer is formed into the cap body (115) and the AlGaAs epitaxial layer is formed into the main body (114), thereby obtaining the ridge strip (110).

4. The method for manufacturing a semiconductor laser according to claim 2, characterized in that: The top end of the cap body (115) comprises a main top wall (1152) and inclined top walls (1153) located on both sides of the main top wall (1152); either end of the main top wall (1152) in the width direction is connected to the constraining side wall (1151) via the inclined top wall (1153); the inclined top wall (1153) and the adjacent constraining side wall (1151) form a positive angle.

5. The method for manufacturing a semiconductor laser according to claim 4, characterized in that: The thickness of the cap body (115) is between 200 nm and 300 nm, and / or, The inner angle is between 120° and 130°, and / or The positive angle is between 15° and 20°.

6. The method for manufacturing a semiconductor laser according to claim 1, characterized in that: The gap width between the groove side walls of the plurality of groove segments and the corresponding strip segments is between 5 μm and 7 μm.

7. The method for manufacturing a semiconductor laser according to any one of claims 1 or 3 to 6, characterized in that: The step of forming a photoresist material layer (130) on the dielectric film (120) comprises: The photoresist is coated on the dielectric film (120) by a spin coating process to form the photoresist material layer (130), wherein the distance between the top of the ridge strip (110) and the upper surface of the photoresist material layer (130) is between 0.5 μm and 1 μm.

8. The method for manufacturing a semiconductor laser according to claim 7, characterized in that: After the exposed photoresist material layer (130) is developed, the distance between the top of the ridge strip (110) and the bottom wall of the reflow groove is greater than 0.5 μm.

9. The method for manufacturing a semiconductor laser according to claim 1 or 8, characterized in that: After the step of developing the exposed photoresist material layer (130), the semiconductor laser manufacturing method further comprises: The photoresist material layer (130) is subjected to surface treatment to reduce the surface tension of the photoresist material layer (130), and / or Surface treatment is performed on portions of the dielectric film (120) located on both side surfaces in the width direction of the ridge strip (110) to improve surface polarity.

10. The method for manufacturing a semiconductor laser according to claim 1, characterized in that: The plurality of strip segments include a wide strip segment (111), a gradient segment (112), and a narrow strip segment (113) that are connected in sequence; The plurality of light-transmitting segments include a wide strip area (141) corresponding to the wide strip segment (111), a gradient area (142) corresponding to the gradient segment (112), and a narrow strip area (143) corresponding to the narrow strip segment (113); The plurality of slot sections include a wide slot section (131) for accommodating the wide strip section (111), a gradual slot section (132) for accommodating the gradual slot section (112), and a narrow slot section (133) for accommodating the narrow strip section (113).

11. A semiconductor laser, characterized in that: The semiconductor laser is manufactured based on the semiconductor laser manufacturing method according to any one of claims 1 to 10.

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