Cavity surface coating method for semiconductor laser

Abstract

The application relates to a cavity surface coating method of a semiconductor laser, comprising the following steps: S102, a molecular layer is selectively grown on the electrode surface area of a semiconductor laser cleaved strip to form a barrier layer with hydrophobic characteristics; and S104, atomic layer deposition is performed on the semiconductor laser cleaved strip with the barrier layer to form a passivation film on the area of the semiconductor laser cleaved strip except the barrier layer covered area. The cavity surface coating method of the semiconductor laser can realize the deposition of the passivation film on the cavity surface of the semiconductor laser cleaved strip and avoid the appearance of the passivation film on the electrode surface of the semiconductor laser, and the problem of mechanical damage of the semiconductor laser cleaved strip caused by uneven stress is avoided.

Description

Technical Field

[0001] This application relates to the field of semiconductor laser chip manufacturing technology, and in particular to a cavity surface coating method for semiconductor lasers. Background Technology

[0002] Optical communication is a high-speed, high-capacity, and secure information transmission technology. High-power semiconductor lasers possess advantages such as small size, light weight, high electro-optical conversion efficiency, long operating life, and high reliability. They are capable of emitting stable, high-power laser sources and are one of the most important components in the development of optical communication technology, often referred to as the "heart" of optical communication and optical networks. The natural cleavage planes of the crystal used in semiconductor lasers (hereinafter referred to as "cavity faces") serve as the end faces of the semiconductor laser and are crucial structures constituting the optical resonant cavity, determining the performance and lifespan of the semiconductor laser.

[0003] In related technologies, oxide films such as aluminum oxide, titanium oxide, and silicon oxide are deposited on the cavity surface of semiconductor lasers. These films are referred to as passivation films in the cavity surface coating application of semiconductor laser cleavage strips. A large number of regularly arrayed electrodes, made of materials such as gold and copper, exist on the surface of the semiconductor laser cleavage strips. These electrodes are connected to external structures via gold wire bonding and are crucial structures for realizing the function of the semiconductor laser. During the gold wire bonding process, the gold wire and electrode must be able to withstand a certain tensile force to ensure a tight connection. However, if a passivation film composed of the aforementioned oxides exists on the electrode surface, the strength of the gold wire bonding will decrease, and may even lead to bonding failure. Therefore, the area selectivity requirement is high during the cavity surface coating process of semiconductor lasers. During cavity surface coating, it is necessary to avoid growing films on the electrode surfaces while depositing the required films on the cavity surface.

[0004] In related technologies, mechanical clamps are typically used to clamp the cleaved strips of semiconductor lasers before coating. While this method of clamping with mechanical clamps can achieve coating on the cavity surface while avoiding the growth of thin films on the electrode surface, it can easily cause uneven stress on the cleaved strips of the semiconductor laser, resulting in mechanical damage. Summary of the Invention

[0005] Based on this, a cavity surface coating method for semiconductor lasers is provided to solve the problem that the cleavage strips of semiconductor lasers are easily subjected to uneven stress and thus suffer mechanical damage during the coating process.

[0006] This application provides a method for cavity surface coating of a semiconductor laser, including the following steps:

[0007] Step S102: Selectively grow a molecular layer on the electrode surface region of the cleaved strip of the semiconductor laser to form a barrier layer with hydrophobic properties; and

[0008] Step S104: Atomic layer deposition is performed on the semiconductor laser cleavage strip on which the barrier layer is formed, so as to form a passivation film in the area of ​​the semiconductor laser cleavage strip other than the area covered by the barrier layer.

[0009] In one embodiment, the semiconductor laser is a gallium arsenide semiconductor laser, a cadmium sulfide laser, an indium phosphide laser, or a zinc sulfide laser, and the electrode material of the cleaved strips of the semiconductor laser is copper, silver, or gold.

[0010] In one embodiment, in step S102, the semiconductor laser cleavage strip is immersed in a solvent for preparing SAMs, so that the barrier layer formed on the electrode surface is a self-assembled monolayer.

[0011] In one embodiment, in step S102, the solvent used for preparing SAMs includes a bis(p-chlorophenyl)trichloroethane solution, an octadecyl mercaptan solution, or an octyl diphenylamine solution.

[0012] In one embodiment, in step S102, the surface of the semiconductor laser cleavage strip containing the electrodes is immersed downwards in a solvent for preparing SAMs.

[0013] In one embodiment, in step S102, a carrier is used to immerse the semiconductor laser cleaving strip in a corresponding solution. The carrier includes a fence and encapsulation caps connected to both ends of the fence. The fence forms a loading space between the encapsulation caps at both ends. The loading space is used to place the semiconductor laser cleaving strip.

[0014] In one embodiment, the vehicle is provided with a pusher and a limiting base plate. The pusher is rotatably connected to the fence, and the limiting base plate is provided with a boss with an inclined surface. The inclined surface of the boss faces the side of the fence where the pusher is located.

[0015] In one embodiment, the fence includes three or more grid plates, and a groove is formed between the inclined surface of the boss and the grid plate of the fence near the inclined surface, the groove being used to limit the bottom end of the semiconductor laser cleaving strip placed into the loading space.

[0016] In one embodiment, the cross-sectional shape of the boss is a right trapezoid;

[0017] Alternatively, the limiting base plate may have multiple protrusions, each protrusion being prismatic in shape and having a triangular cross-section.

[0018] In one embodiment, in step S104, the material for atomic layer deposition of the semiconductor laser cleavage strip includes SiO2, Al2O3 or TiO2, and the deposition temperature is 90℃-500℃.

[0019] The aforementioned cavity surface coating method for semiconductor lasers involves selectively growing a molecular layer on the electrode surface of the semiconductor laser cleavage strip in step S102 to form a hydrophobic barrier layer. This barrier layer isolates the electrode surface, preventing atomic layer deposition during step S104. The barrier layer then blocks the atomic layer deposition process, preventing deposition on the electrode surface. The areas of the semiconductor laser cleavage strip not covered by the barrier layer form passivation films, thus achieving passivation film deposition on the cavity surface of the semiconductor laser cleavage strip while avoiding passivation film formation on the electrode surface. Because this cavity surface coating method uses immersion and atomic layer deposition, it eliminates the need for external force to fix the cleavage strip, reducing the risk of mechanical damage due to uneven stress on the semiconductor laser cleavage strip. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating the steps of a cavity surface coating method for a semiconductor laser according to an embodiment of this application.

[0022] Figure 2 This is a schematic diagram of the cross-sectional structure after a barrier layer is formed on the electrode surface of a cleavage strip in a semiconductor laser cavity surface coating method according to one embodiment.

[0023] Figure 3 This is a schematic diagram illustrating the effect of cavity surface coating on a semiconductor laser obtained by using the cavity surface coating method of an embodiment of this application.

[0024] Figure 4 This is a schematic diagram of the cross-sectional structure of a semiconductor laser after a passivation film has been deposited and formed in a cavity surface coating method for a semiconductor laser, as one embodiment.

[0025] Figure 5In one embodiment of a semiconductor laser cavity surface coating method, aluminum oxide is selectively grown in the gold electrode region to determine the water contact angle under different pulse cycles.

[0026] Figure 6 In one embodiment of the cavity surface coating method for a semiconductor laser, XPS spectra of a laser substrate surface (indium phosphide substrate) with a 15 nm thick aluminum oxide thin film co-deposited and a gold electrode treated using the cavity surface coating method of the semiconductor laser of this application are compared.

[0027] Figure 7 The thickness of the aluminum oxide film deposited on the silicon substrate without the barrier layer and on the gold-plated silicon wafer after the barrier layer is grown, under different pulse cycle numbers.

[0028] Figure 8 The images show the results of gold wire bonding experiments on three gold-plated wafers with different treatments. Figures (a), (b), and (c) show the results of the same number of gold wire bonding processes performed on the surfaces of a clean gold-plated silicon wafer without any treatment, a gold-plated silicon wafer with a barrier layer grown and aluminum oxide deposited in this case, and a gold-plated silicon wafer without a barrier layer grown and aluminum oxide deposited in this case, respectively. The bonding quality was observed under a super depth-of-field microscope.

[0029] Figure 9 This is a schematic diagram of the structure of the carrier used in the immersion process in the cavity surface coating method of a semiconductor laser according to an embodiment of this application.

[0030] Figure 10 This is a schematic diagram of the carrier used in the immersion process during the cavity surface coating method of a semiconductor laser according to one embodiment of this application.

[0031] Figure 11 This is an exploded view of the carrier used in the immersion process in the cavity surface coating method of a semiconductor laser according to an embodiment of this application.

[0032] Figure 12 This is an exploded view of the pusher and the enclosure of the carrier used in the immersion process in a cavity surface coating method for a semiconductor laser according to an embodiment of this application. Detailed Implementation

[0033] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0034] It should be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0035] The terms “vertical,” “horizontal,” “up,” “down,” “left,” “right,” and similar expressions are for illustrative purposes only and do not represent the only possible implementation.

[0036] It should be understood that the terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” and “horizontal,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0037] The semiconductor lasers used in this invention include, but are not limited to, gallium arsenide (GaAs) lasers, cadmium sulfide (CDS) lasers, indium phosphide (INP) lasers, or zinc sulfide (ZnS) lasers.

[0038] Combination Figures 1 to 3 As shown in the embodiments of this application, the cavity surface coating method for a semiconductor laser includes the following steps:

[0039] Step S102 involves selectively growing a molecular layer on the electrode surface region of the cleaved strip of the semiconductor laser to form a barrier layer with hydrophobic properties. The barrier layer can be a SAM (self-assembled monolayer). For example... Figure 2 As shown, Figure 2 A schematic diagram of the cross-section after forming a barrier layer on the electrode surface of a cleaved strip for a semiconductor laser. Figure 2 This shows that after step S102, the electrode J of the semiconductor laser cleavage strip P is covered by the formed barrier layer G.

[0040] For ease of understanding, the solution used to grow and form self-assembled monolayers will be referred to as the solvent for SAMs preparation.

[0041] In step S102, the semiconductor laser cleavage strip is immersed in a solvent for preparing SAMs to form a self-assembled monolayer on the electrode surface. Specifically, the molecules in the solvent for preparing SAMs consist of head groups, tail groups, and carbon chains. SAMs are produced by chemisorbing head groups from the gas or liquid phase onto a substrate, followed by the slow organization of tail groups. Initially, at low molecular densities on the surface, adsorbed molecules form disordered clusters or ordered two-dimensional planar phases. At higher molecular coverage, after minutes to hours, crystalline or semi-crystalline structures begin to form on the three-dimensional substrate surface. Head groups assemble together on the substrate, while tail groups assemble away from the substrate. Closely packed molecular regions nucleate and grow until the substrate surface is covered by a single monolayer. Adsorbate molecules readily adsorb because they lower the surface free energy of the substrate and are stabilized due to the strong chemisorption of the head groups. In step S102, the corresponding inert groups at the tail of the molecular layer will hinder the chemical adsorption reaction of the precursor of the deposited film, so that it cannot be adsorbed and bound to the precursor in the atomic layer deposition (ALD) process, thereby blocking the deposition process of the atomic layer at the corresponding electrode surface and achieving the barrier to the adsorption of the precursor of atomic layer deposition.

[0042] In step S102, the solvents used for SAMs preparation include, but are not limited to, DDT (bis(p-chlorophenyl)trichloroethane, chemical formula C14H9Cl5) solution, ODT (octadecyl mercaptan, chemical formula C18H38S) solution, or ODPA (octyl diphenylamine, chemical formula C20H27N) solution. The tail groups of DDT, ODT, and ODPA are all corresponding inert groups, thus preventing them from adsorbing and binding with the precursors in the atomic layer deposition (ALD) process. Therefore, the self-assembled monolayer acts as a barrier layer, achieving the barrier against the adsorption of precursors in ALD.

[0043] It's important to clarify that the semiconductor laser cleaving strip is immersed in the solvent used for SAM (Synthetic Atoms) preparation, with the electrode-containing surface facing downwards. More precisely, the electrode-containing surface of the semiconductor laser cleaving strip is immersed in the SAM preparation solvent with the electrode-containing surface facing down. By immersing the electrode in the SAM preparation solvent, the thiol groups of the molecular head groups in the SAM preparation solvent bind and adsorb onto the electrode surface, growing hydrophobic SAMs on the electrode surface. However, on other surfaces of the semiconductor laser (e.g., the cavity surface), the molecules in the SAM preparation solvent do not adsorb and grow SAMs on them. In other words, the areas of the semiconductor laser cleaving strip outside the SAM-covered areas are blocked from forming SAMs and remain exposed, allowing for subsequent atomic layer deposition on these areas.

[0044] In step S102, the solvent for preparing SAMs can be contained in a processing container. Thus, the cleaned semiconductor laser cleavage strip is placed into the processing container, and the semiconductor laser cleavage strip can be soaked in the solvent for preparing SAMs.

[0045] Step S104: Atomic layer deposition is performed on the semiconductor laser cleavage strip with the barrier layer formed to form a passivation film in the area of ​​the semiconductor laser cleavage strip other than the area covered by the barrier layer.

[0046] Based on the hydrophobic properties of the barrier layer formed on the electrode surface in step S102, it serves as a barrier, preventing the adsorption and bonding of the precursor on the electrode, thereby blocking the atomic layer deposition process. This prevents the growth of a passivation film on the electrode surface, while the areas of the semiconductor laser cleavage strip not covered by the barrier layer form a passivation film. It should be noted that after step S102, the surface of the semiconductor laser cleavage strip is relatively smooth, allowing the atomic layer deposition process to achieve excellent thin film step coverage. Due to the excellent step coverage characteristics of atomic layer deposition, a uniform and dense passivation film is deposited on the cavity surface of the semiconductor laser. Based on this, combined with... Figure 3 and Figure 4 As shown, a uniform and dense passivation film M will grow on the cavity surface of the cleavage strip P of the semiconductor laser. Specifically, because the barrier layer G formed in step S102 covers the surface of the electrode J and has a barrier effect, after step S104, a passivation film M is formed on the cavity surface of the cleavage strip P of the semiconductor laser, while the area covered by the barrier layer G will not deposit, and thus no passivation film M will be formed.

[0047] It's important to note that step coverage is a key indicator of deposition quality. If the surface used for deposition has faults or uneven areas, the thickness of the deposited film (i.e., passivation film) will be uneven. Step coverage measures the thickness loss of the film at the step, specifically the ratio of the film thickness at the step to the thickness at the flat area. A step coverage closer to 1 indicates a smaller difference in film thickness between the step (bottom or sidewall) and the flat area; a step coverage further away from 1 (i.e., less than 1) indicates a thinner film thickness at the step compared to the flat area.

[0048] Atomic layer deposition (ALD) involves multiple alternating cycles of deposition and cleaning. ALD can be performed in a reaction chamber. Specifically, during the alternating cycles, after each introduction of the gaseous precursor into the reaction chamber, an inert gas purging pulse is applied to clean the chamber, ensuring its cleanliness and thus contributing to the quality of the passivation film deposited through alternating cycles. During ALD, the precursor reacts with groups on the substrate surface, growing the film layer by layer.

[0049] In some embodiments, the deposition temperature during atomic layer deposition on the cleaved strips of the semiconductor laser is 90°C-500°C. Specifically, the deposition temperature can be 90°C, 140°C, 260°C, 380°C, or 500°C. The materials used for deposition include, but are not limited to, SiO2, Al2O3, or TiO2. In some embodiments, the thickness of the passivation film can be 5nm-100nm. Specifically, the thickness of the passivation film can be 5nm, 15nm, 25nm, 45nm, 65nm, 75nm, or 100nm, and is not limited thereto.

[0050] The cavity surface coating method for a semiconductor laser according to this application selectively grows a molecular layer in the growth region of the electrode surface of the semiconductor laser cleavage strip in step S102 to form a barrier layer with hydrophobic properties. This barrier layer isolates the electrode surface, so that in step S104, when atomic layer deposition is performed on the semiconductor laser cleavage strip, the barrier layer blocks the atomic layer deposition process, preventing deposition on the electrode surface. The areas of the semiconductor laser cleavage strip not covered by the barrier layer form a passivation film. This achieves the deposition of a passivation film on the cavity surface of the semiconductor laser cleavage strip while avoiding the formation of a passivation film on the electrode surface of the semiconductor laser. Because this cavity surface coating method for a semiconductor laser uses immersion and atomic layer deposition, it eliminates the need for external force to fix the laser cleavage strip to be coated, thus reducing the risk of mechanical damage due to uneven stress on the semiconductor laser cleavage strip.

[0051] It should be noted that when using the cavity surface coating method for semiconductor lasers to coat the cavity surface of semiconductor lasers, the parameters such as the type of laser cleavage strips, the type of SAMs, the SAMs processing time, the SAMs processing temperature, the ALD temperature, the ALD pulse time, and the type of ALD precursor in the above technical solution can be adjusted according to the actual application conditions.

[0052] For example, the cavity surface of an indium phosphide laser is coated.

[0053] An indium phosphide laser was immersed in the solvent used for preparing SAMs to grow a barrier layer. After immersion for 24 hours, it was placed in an atomic layer deposition chamber to deposit and grow an alumina film with 30-210 pulse cycles, and then tested.

[0054] By measuring the water contact angle and performing XPS tests on the gold substrate during the cavity surface coating process, it was found that the above method can achieve good efficiency in depositing passivation films on the cavity surface of the semiconductor laser cleavage strip, and there are no passivation films on the electrode surface of the semiconductor laser.

[0055] Specifically, in combination Figure 5 As shown, Figure 5 The water contact angle of selectively grown alumina on the gold electrode region of an indium phosphide laser under different pulse cycles was measured. As the number of atomic layer deposition precursor pulse cycles increased, the water contact angle decreased, indicating a reduction in the hydrophobicity of the gold electrode surface and a decrease in the adsorption of the precursor during thin film deposition. XPS spectra were measured on the laser substrate surface (indium phosphide substrate) where a 15 nm thick alumina film was co-deposited, and on the gold electrode treated using the cavity surface deposition method of the semiconductor laser described in this application. Specifically, combined with... Figure 6 As shown, Figure 6 XPS spectra of a laser substrate (indium phosphide substrate) with a 15 nm thick aluminum oxide film deposited on it and a gold electrode treated with the cavity surface deposition method of the semiconductor laser of this application are shown. Figure 6 shows that the aluminum content on the indium phosphide substrate with the 15 nm thick aluminum oxide film deposited on it is relatively high. This indicates that the aluminum oxide film was successfully deposited on the cavity surface of the cleaved strips of the semiconductor laser. In contrast, the aluminum content on the gold electrode surface treated with the cavity surface deposition method of the semiconductor laser of this application is relatively low, thus achieving the desired film deposition on the cavity surface while avoiding film growth on the electrode surface.

[0056] It should be noted that the contact angle refers to the angle between the tangent line drawn at the gas-liquid interface at the junction of the gas, liquid, and solid phases, on the liquid side, and the solid-liquid interface line. It is a measure of the degree of wetting. The contact angle of a liquid on the surface of a solid material is an important parameter for measuring the wettability of the liquid on the material surface. By measuring the contact angle, information about the solid-liquid and solid-gas interface interactions on the material surface can be obtained. The water contact angle measurement can reflect the ratio of the density of hydrophilic groups to the density of hydrophobic groups on the surface. Since the two precursors used in atomic layer deposition rely on hydrophilic hydroxyl groups for reaction and adsorption, a larger water contact angle indicates a smaller number of reactive groups on the surface of the ALD-deposited alumina, which can be considered as a smaller content of alumina deposited on the gold electrode surface.

[0057] In some embodiments, a self-assembled molecular barrier layer is grown on a gold-plated silicon wafer, followed by atomic layer deposition. The self-assembled molecular barrier layer material is an ODT material, the growth temperature is 50 degrees Celsius, and an alumina film is deposited at 130 degrees Celsius. The film thickness of the gold-plated silicon wafers with deposited alumina films of 0-200 precursor pulse cycles is measured using ellipsometry. Figure 7 As shown, Figure 7 The image shows the thickness of alumina films deposited on a silicon substrate without a barrier layer and on a gold-plated silicon wafer after a barrier layer has been grown, at different pulse cycle numbers. Figure 7 It can be seen that the thickness of the grown barrier layer is about 1.7 nm. In the subsequent deposition process, the untreated gold-plated wafer surface can deposit aluminum oxide film normally, just like the silicon wafer. The thickness of the aluminum oxide film grown on the gold-plated wafer is about 7.5 nm. However, the film thickness on the gold-plated wafer after the barrier layer is grown is basically unchanged. This proves that the barrier layer prevents the growth of aluminum oxide film on its surface, thereby achieving the goal of blocking the deposition of film on the metal electrode surface of the semiconductor laser and achieving the purpose of depositing passivation film on the cavity surface of the semiconductor laser.

[0058] Combination Figure 8 As shown, Figure 8 The results of gold wire bonding experiments on three different treated gold-plated sheets are shown. Figure 8 Figures (a), (b), and (c) show the bonding quality of a gold-plated silicon wafer with a clean, untreated surface, a gold-plated silicon wafer with a barrier layer grown and aluminum oxide deposited (as in this case), and a gold-plated silicon wafer without a barrier layer grown and aluminum oxide deposited (as in this case), respectively, after undergoing the same number of gold wire bonding processes. These images are observed under a super depth-of-field microscope. Figure 8As can be seen, gold wire bonding can be successfully performed on the surface of the untreated gold-plated silicon wafer and the gold-plated silicon wafer with a barrier layer and aluminum oxide deposition as described in this case. However, gold wire bonding cannot be successfully performed on the gold-plated silicon wafer without a barrier layer and aluminum oxide deposition as described in this case. The aluminum content of the gold wire bonding is low, resulting in poor solder joints and detachment. This demonstrates that the cavity surface coating method in this invention can achieve cavity surface deposition of aluminum oxide film, and prevent the deposition of aluminum oxide film on the gold electrode without affecting the subsequent gold wire bonding process.

[0059] It should be noted that the barrier layer can be grown by immersion or by saturated vapor deposition.

[0060] To facilitate the subsequent growth of the barrier layer on the cleaved laser strips, the cleaved semiconductor laser strips can be grown using methods such as... Figures 9 to 12 The deposition process is completed using a carrier. Taking immersion growth as an example, in step S102, a dedicated carrier can be used to carry the semiconductor laser cleavage strip and immerse it in the corresponding solution to assist in the immersion process. Specifically, in step S102, the carrier carrying the semiconductor laser cleavage strip is immersed in a cleaning solution; correspondingly, in step S102, the carrier carrying the semiconductor laser cleavage strip is immersed in a solvent for SAMs preparation.

[0061] During the immersion process of the semiconductor laser cleavage strip assisted by this carrier, no clamping force is exerted on the semiconductor laser cleavage strip, allowing the semiconductor laser cleavage strip to complete the immersion in a natural state, thereby avoiding mechanical damage caused by uneven stress on the semiconductor laser cleavage strip.

[0062] It should be noted that the liquid phase growth is carried out by water bath heating at 20℃-90℃ for 12h-72h, while the gas phase is treated in a saturated vapor atmosphere of SAMs materials for 12h-72h.

[0063] For example, the following will combine Figures 9 to 12 The structure of the vehicle is illustrated in the diagram.

[0064] Combination Figure 9 and Figure 10 As shown, the carrier includes a fence 10 and encapsulation covers 20 connected to both ends of the fence 10, with the fence 10 forming a loading space between the encapsulation covers 20 at both ends. The loading space is used to place the cleaving strip P of a semiconductor laser.

[0065] The vehicle is also provided with a pusher 30 and a limiting base plate 40, the pusher 30 being rotatably connected to the fence 10. The limiting base plate 40 is provided with a boss 40a having a slope 40b, the slope 40b facing the side of the fence 10 where the pusher 30 is located.

[0066] The fence 10 may include three or more grid panels 10a, each of which is a sheet material with a perforated grid. These grid panels 10a are connected in sequence to enclose each other and form a loading space with the encapsulation covers 20 at both ends.

[0067] For example, combined Figure 9 As shown, the fence 10 includes four adjacent fence plates 10a, and the pusher 30 is disposed on the fence plate 10a opposite to the inclined surface 40b.

[0068] It should be noted that a groove 40c is formed between the inclined surface 40b of the boss 40a and the grid plate 10a of the fence 10 near the inclined surface 40b. The groove 40c is used to limit the bottom end of the semiconductor laser cleaving strip P placed into the loading space.

[0069] The vehicle works on the following principle: Combining Figure 11 As shown, before using the carrier, the lower encapsulation cover 20 is installed together with the fence 10, and the limiting base plate 40 is installed. Then, the pusher 30 is rotated outward so that it does not interfere with the vertical placement of the laser semiconductor laser cleaving strip P into the corresponding groove 40c. After the laser semiconductor laser cleaving strip P is placed vertically in the groove 40c between the inclined surface 40b of the pusher 30 and the grid plate 10a of the fence 10 near the inclined surface 40b, the pusher 30 is turned so that its rotation causes the semiconductor laser cleaving strip P to tilt naturally. Since the bottom end of the semiconductor laser cleaving strip P is limited in the groove 40c, its top end eventually leans against the grid plate 10a on the other side of the fence 10. Then, the semiconductor laser cleaving strip P is placed at a certain tilt angle. After placing the semiconductor laser cleaving strip P, the upper encapsulation cover 20 is fixed to the other end of the fence 10 to form a loading space. Finally, the semiconductor laser cleavage strip P, along with the carrier, is immersed in the solvent used for SAMs preparation. The solvent enters the loading space through the cutout in the gate plate 10a to immerse the semiconductor laser cleavage strip P. Based on the natural tilting mechanism pushed by the pusher 30, the semiconductor laser cleavage strip P is stably positioned within the carrier without requiring external force to fix it. This effectively avoids the problem of mechanical damage caused by uneven stress on the semiconductor laser cleavage strip P.

[0070] Understandably, when the semiconductor laser cleavage strip P is tilted by the pusher 30, the surface of the semiconductor laser cleavage strip P near the bottom abuts against the inclined surface 40b of the boss 40a, and will not be subjected to localized concentrated stress, thereby further reducing the probability of mechanical damage caused by uneven stress on the semiconductor laser cleavage strip P.

[0071] In some embodiments, after immersing the semiconductor laser cleaving strip P along with the carrier entirely in a solvent for SAMs preparation, it is then heated in a water bath at 20°C-900°C for 12-72 hours. This maintains a suitable immersion time at an appropriate temperature to facilitate the formation of a passivation film on the surface of the semiconductor cleaving strip.

[0072] Preferably, the cross-sectional shape of the boss 40a is a right trapezoid, which facilitates the processing of the limiting base plate 40. When processing the limiting base plate 40 with the boss 40a using sheet metal, only one end of the sheet metal needs to be cut to reduce the amount of material cut and avoid material waste.

[0073] Of course, in some embodiments, the limiting base plate 40 is provided with multiple bosses 40a, which are prism-shaped and have a triangular cross-section. In this way, the positioning grooves formed between the multiple prisms can be used to limit one end of the multiple semiconductor laser cleavage strips P.

[0074] The pusher 30 can be a block or a rod, and there is no limitation on it. The pusher 30 and the fence plate 10a on the side of the fence 10 near the groove 40c can be rotatably connected by a pivot.

[0075] Combination Figure 10 and Figure 12 As shown, the pushing member 30 includes a rotating part 30a, a tossing part 30b, and a pushing part 30c. The rotating part 30a is rotatably connected to the grid plate 10a. The grid plate 10a has a clearance groove 101, which provides clearance space for the rotation of the pushing member 30. The side wall of the clearance groove 101 has a mating groove 102, and the rotating part 30a is rotatably mated with the mating groove 102. When using the pushing member 30 to push multiple semiconductor laser cleaving strips P, it is only necessary to toss the tossing part 30b to make the pushing member 30 rotate relative to the grid plate 10a around the axis of the rotating part 30a, so that the pushing part 30c can push down the multiple semiconductor laser cleaving strips P, so that the multiple semiconductor laser cleaving strips P are placed obliquely in the loading space of the carrier.

[0076] It should be noted that, in the embodiments of this application, 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 indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0077] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0078] In this application, unless otherwise expressly specified and limited, the first feature being "on" or "below" the second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium.

[0079] 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.

[0080] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but 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 present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for cavity surface coating of a semiconductor laser, characterized in that, Includes the following steps: Step S102: Selectively grow a molecular layer on the electrode surface region of the cleaved strip of the semiconductor laser to form a barrier layer with hydrophobic properties. as well as Step S104: Atomic layer deposition is performed on the semiconductor laser cleaving strip on which the barrier layer is formed, so as to form a passivation film in the area of ​​the semiconductor laser cleaving strip other than the area covered by the barrier layer. In step S102, a carrier is used to immerse a semiconductor laser cleaving strip in a corresponding solution. The carrier includes a fence and encapsulation caps connected to both ends of the fence. The fence forms a loading space between the encapsulation caps at both ends. The loading space is used to place the semiconductor laser cleaving strip. The carrier is provided with a pusher and a limiting base plate. The pusher is rotatably connected to the fence. The limiting base plate is provided with a boss with an inclined surface. The inclined surface of the boss faces the side of the fence where the pusher is located. The fence includes three or more grid plates. A groove is formed between the inclined surface of the boss and the grid plate of the fence near the inclined surface. The groove is used to limit the bottom end of the semiconductor laser cleaving strip placed into the loading space.

2. The cavity surface coating method for a semiconductor laser according to claim 1, characterized in that, The semiconductor laser is a gallium arsenide semiconductor laser, a cadmium sulfide laser, an indium phosphide laser, or a zinc sulfide laser, and the electrode material of the cleaved strip of the semiconductor laser is copper, silver, or gold.

3. The cavity surface coating method for a semiconductor laser according to claim 1 or 2, characterized in that, In step S102, the semiconductor laser cleavage strip is immersed in a solvent for preparing SAMs, so that the barrier layer formed on the electrode surface is a self-assembled monolayer.

4. The cavity surface coating method for a semiconductor laser according to claim 3, characterized in that, In step S102, the solvents used for preparing SAMs include bis(p-chlorophenyl)trichloroethane solution, octadecyl mercaptan solution, or octyl diphenylamine solution.

5. The cavity surface coating method for a semiconductor laser according to claim 4, characterized in that, In step S102, the electrode-containing surface of the semiconductor laser cleavage strip is immersed downwards in a solvent for preparing SAMs.

6. The cavity surface coating method for a semiconductor laser according to claim 1, characterized in that, The cross-sectional shape of the boss is a right trapezoid.

7. The cavity surface coating method for a semiconductor laser according to claim 1, characterized in that, The limiting base plate is provided with a plurality of protrusions, which are prism-shaped and have a triangular cross-section.

8. The cavity surface coating method for a semiconductor laser according to claim 1, characterized in that, In step S104, the material used for atomic layer deposition of the semiconductor laser cleavage strips includes SiO2, Al2O3, or TiO2, and the deposition temperature is 90℃-500℃.

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