Semiconductor laser preparation method and semiconductor laser

Abstract

The present invention discloses a semiconductor laser preparation method and a semiconductor laser, and relates to the technical field of semiconductor lasers. The semiconductor laser preparation method comprises: providing a laser chip; placing the laser chip in a vacuum environment at a preset temperature; growing a zinc atomic layer on the cavity surface of the laser chip; ionizing the zinc atomic layer to generate zinc ions, so as to induce the zinc ions to diffuse from the cavity surface to the region of the quantum well layer of the laser chip close to the cavity surface. The semiconductor laser preparation method provided by the present invention has the characteristics of higher quantum well intermixing efficiency, better intermixing quality, and simple and quick operation steps.

Description

Technical Field

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

[0002] In the semiconductor laser manufacturing process, in order to solve the problem of catastrophic optical mirror damage (COMD), it is necessary to induce quantum well intermixing in the area of ​​the quantum well layer close to the cavity surface to adjust the band gap characteristics of the quantum well layer in the window area. The mainstream method of inducing quantum well intermixing on the market is: before the epitaxial wafer is packaged with electrodes, the window area and non-window area are defined by P-side lithography, a zinc oxide film is grown in the window area, and a mask layer is grown in the non-window area for protection to avoid blue shift. After that, high-temperature annealing is used to induce zinc ions in the window area to enter the quantum well layer. After the quantum well intermixing is completed, the mask layer is etched away and the zinc oxide film is removed.

[0003] In this method, on the one hand, the window area and the non-window area are defined by photolithography, and the process of removing the mask layer after the window area grows is cumbersome and complicated; on the other hand, the zinc ions in the window area need to pass through the upper waveguide layer and the barrier layer in sequence to enter the quantum well layer. The diffusion path is long, resulting in low diffusion efficiency and poor diffusion effect; and the long diffusion path leads to a higher annealing temperature. In order to avoid high temperature damage to the electrode, the electrode can only be grown after the mixing is completed, which complicates the process. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a semiconductor laser, which has the characteristics of high quantum well intermixing efficiency, good intermixing quality and simple and quick operation steps.

[0005] Another object of the present invention is to provide a semiconductor laser having better quality.

[0006] The embodiment of the present invention provides a technical solution:

[0007] A method for preparing a semiconductor laser, comprising:

[0008] Provide laser chips;

[0009] Placing the laser chip in a vacuum environment at a preset temperature;

[0010] growing a zinc atomic layer on the cavity surface of the laser chip;

[0011] The zinc atomic layer is ionized to generate zinc ions, so as to induce the zinc ions to diffuse from the cavity surface to a region of the quantum well layer of the laser chip close to the cavity surface.

[0012] In an optional embodiment, before the step of placing the laser chip in a vacuum environment at a preset temperature, the semiconductor laser preparation method further includes:

[0013] The surfaces of the P-side electrode and the N-side electrode of the laser chip are respectively covered with high-temperature protection members.

[0014] In an optional embodiment, before the step of placing the laser chip in a vacuum environment at a preset temperature, the semiconductor laser preparation method further includes:

[0015] The portions of the metal layers on both sides of the laser chip close to the cavity surface are removed using the P-side electrode and the N-side electrode as boundaries.

[0016] In an optional embodiment, the step of growing a zinc atomic layer on the cavity surface of the laser chip includes:

[0017] A zinc atomic layer is grown on the cavity surface by magnetron sputtering.

[0018] In an optional embodiment, the number of atomic layers of the zinc atomic layer is between two and three; and / or,

[0019] The thickness of the zinc atomic layer is between 0.5 nm and 1.5 nm.

[0020] In an optional embodiment, the step of ionizing the zinc atomic layer to generate zinc ions to induce the zinc ions to diffuse from the cavity surface to a region of the quantum well layer of the laser chip close to the cavity surface comprises:

[0021] A negative bias voltage is applied to the substrate of the laser chip to ionize the zinc atomic layer to generate zinc ions.

[0022] In an optional embodiment, after the step of ionizing the zinc atomic layer to generate zinc ions to induce the zinc ions to diffuse from the cavity surface to a region of the quantum well layer of the laser chip close to the cavity surface, the semiconductor laser manufacturing method further includes:

[0023] An oxygen ion source and residual zinc ions are provided to generate a zinc oxide film layer covering the cavity surface, which serves as a passivation film and / or an optical film of the laser chip.

[0024] In an optional embodiment, after the step of providing an oxygen ion source and residual zinc ions to generate a zinc oxide film layer covering the cavity surface as a passivation film and / or optical film of the laser chip, the semiconductor laser preparation method further includes:

[0025] When the quantum well layer needs to be mixed again, the zinc oxide film layer is ionized to generate zinc ions.

[0026] In an optional embodiment, the step of ionizing the zinc oxide film layer to generate zinc ions comprises:

[0027] The cavity surface is vertically irradiated with laser light of a preset wavelength band to stimulate partial ionization of the zinc oxide film layer to generate zinc ions.

[0028] An embodiment of the present invention further provides a semiconductor laser, wherein the semiconductor laser is prepared by the above-mentioned semiconductor laser preparation method, and the semiconductor laser preparation method comprises:

[0029] Provide laser chips;

[0030] Placing the laser chip in a vacuum environment at a preset temperature;

[0031] growing a zinc atomic layer on the cavity surface of the laser chip;

[0032] The zinc atomic layer is ionized to generate zinc ions, so as to induce the zinc ions to diffuse from the cavity surface to a region of the quantum well layer of the laser chip close to the cavity surface.

[0033] Compared with the prior art, the semiconductor laser preparation method provided by the present invention grows a zinc atomic layer on the cavity surface of the laser chip, and after zinc ions are generated by ionization, the zinc ions are induced to diffuse directly from the cavity surface into the area of ​​the quantum well layer close to the cavity surface to achieve quantum well intermixing. It eliminates the tedious operations of defining the window area and the non-window area by P-face lithography, and removing the mask layer after the window area is first grown. In addition, the diffusion path of the zinc ions is greatly shortened, the diffusion efficiency is higher, and the diffusion effect is better; and the shortened path leads to a greatly reduced annealing temperature required, and the intermixing process can be carried out after the laser chip is systematically prepared and formed, that is, after the electrode growth is completed, and the process is greatly simplified. Therefore, the beneficial effects of the semiconductor laser preparation method provided by the present invention include: higher quantum well intermixing efficiency, better intermixing quality, and simple and quick operation steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] 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.

[0035] Figure 1A flowchart of a method for preparing a semiconductor laser provided by an embodiment of the present invention;

[0036] Figure 2 for Figure 1 A schematic diagram of the structure of the laser chip provided in step S101;

[0037] Figure 3 for Figure 1 A schematic diagram of the structure of the laser chip after being covered with a high temperature protection member in step S102;

[0038] Figure 4 for Figure 1 A schematic diagram of the structure of the laser chip after the growth of the zinc atomic layer is completed in step S104;

[0039] Figure 5 for Figure 1 Schematic diagram of the structure of the laser chip in which a zinc oxide film layer is formed on the cavity surface in step S106.

[0040] Icon: 100-laser chip; 110-cavity surface; 120-quantum well layer; 200-high temperature protection component; 300-zinc atomic layer; 400-zinc oxide film layer. DETAILED DESCRIPTION

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0046] 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.

[0047] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0048] Example

[0049] See also Figure 1 , Figure 1 The figure shows a flowchart of a method for preparing a semiconductor laser provided in this embodiment. The method for preparing a semiconductor laser may include:

[0050] Step S101 , providing a laser chip 100 .

[0051] Please refer to Figure 2 , Figure 2 FIG. 1 is a schematic structural diagram of the laser chip 100 provided in step S101 .

[0052] The laser chip 100 provided in this embodiment is a conventional edge-emitting laser chip 100 with a complete structure, including a substrate, an N-side electrode grown on the N side of the substrate, and an N-type layer structure, an active layer, a P-type layer structure and a metal layer grown on the P side of the substrate. The N-type layer structure may include an N-type buffer layer, an N-type cladding layer and an N-type waveguide layer, etc., the P-type layer structure may include a P-type waveguide layer, a P-type cladding layer and a P-type contact layer, etc. stacked in sequence, the metal layer forms a P-side electrode, and the active layer includes a quantum well layer 120 and barrier layers on both sides of the quantum well layer 120.

[0053] Please continue reading Figure 1 , the semiconductor laser preparation method may further include:

[0054] Step S102 : Covering the surfaces of the P-side electrode and the N-side electrode of the laser chip 100 with a high temperature protection member 200 .

[0055] Please refer to Figure 3 , Figure 3 FIG. 1 is a schematic structural diagram of the laser chip 100 after being covered with the high temperature protection member 200 in step S102 .

[0056] The surfaces of the P-side electrode and the N-side electrode of the laser chip 100 are respectively covered with high temperature protection members 200 to prevent the P-side electrode and the N-side electrode from being damaged by high temperature, including melting and deformation, in the subsequent step of heating the laser chip 100 .

[0057] It is understandable that the shape and structure of the high temperature protection member 200 covering the P side surface needs to adapt to the step structure formed on the side surface of the laser chip 100 due to the ridges, and match the step structure to achieve complete protection of the P side surface.

[0058] In fact, in this embodiment, the two high temperature protection members 200 completely cover the side surface and the N side surface of the laser chip 100, and the high temperature protection member 200 is made of glass with a thickness of preferably 120 mm, covering the laser chip 100 to form a "sandwich" structure.

[0059] In other embodiments, other materials with good thermal stability, smooth surface and good thermal insulation effect may be selected according to actual application conditions.

[0060] Moreover, in another embodiment, the P-side electrode and the N-side electrode can be used as boundaries to remove portions of the metal layer on both sides of the laser chip 100 close to the cavity surface 110, thereby avoiding high-temperature damage to the portion of the metal layer close to the cavity surface 110 in subsequent high-temperature treatment steps and affecting the electrode.

[0061] Please continue reading Figure 1 , the semiconductor laser preparation method may further include:

[0062] Step S103 , placing the laser chip 100 in a vacuum environment at a preset temperature.

[0063] In this embodiment, since zinc ions diffuse from the cavity surface 110 in the subsequent steps, the diffusion path is short and the required preset temperature is relatively low, lower than 530° C., and the preset temperature in this embodiment is preferably 500° C.

[0064] In fact, in this embodiment, the laser chip 100 covered with the high temperature protection member 200 is placed in a passivation chamber, the passivation chamber provides a vacuum environment of a preset temperature, and the subsequent steps are all completed in the passivation chamber.

[0065] Due to the protective effect of the two high temperature protection members 200 , the temperature of the side surface and the N side surface of the laser chip 100 does not exceed 300° C., which can ensure the stability of the P-side electrode and the N-side electrode.

[0066] Step S104 , growing a zinc atomic layer 300 on the cavity surface 110 of the laser chip 100 .

[0067] Please refer to Figure 4 , Figure 4 FIG. 1 is a schematic diagram of the structure of the laser chip 100 after the growth of the zinc atomic layer 300 is completed in step S104 .

[0068] It should be noted that the cavity surface 110 can be either the front cavity surface or the rear cavity surface, and the zinc atomic layer 300 can be grown on both the front cavity surface and the rear cavity surface at the same time, which can be selected according to actual application conditions.

[0069] If the thickness of the zinc atomic layer 300 grown on the cavity surface 110 is too large, the subsequent intermixing will be too deep, which will reduce the effective recombination of carriers and affect the working efficiency of the device. If the thickness of the zinc atomic layer 300 is too small, the subsequent intermixing will be too shallow, the intermixing effect will be poor, and the effect of optimizing the band gap characteristics cannot be achieved.

[0070] Therefore, in this embodiment, the subsequent intermixing depth is controlled by controlling the deposition amount of zinc atoms, that is, the thickness of the zinc atomic layer 300. Preferably, in this embodiment, the thickness of the zinc atomic layer 300 is between 0.5 nm and 1.5 nm.

[0071] In fact, in this embodiment, the growth method of the zinc atomic layer 300 is magnetron sputtering, which is completed in the passivation chamber. The specific deposition thickness is two to three atomic layers, that is, the number of atomic layers of the zinc atomic layer 300 is between two and three layers.

[0072] Please continue reading Figure 1 , the semiconductor laser preparation method may further include:

[0073] In step S105 , the zinc atomic layer 300 is ionized to generate zinc ions, so as to induce the zinc ions to diffuse from the cavity surface 110 to the region of the quantum well layer 120 of the laser chip 100 close to the cavity surface 110 .

[0074] Specifically, a negative bias voltage is applied to the substrate of the laser chip 100 to ionize the zinc atomic layer 300 to generate zinc ions. In a vacuum environment at 500° C., the ionized zinc ions diffuse directly from the cavity surface 110 to the quantum well layer 120 , and the diffusion path is extremely short.

[0075] Step S106 , providing an oxygen ion source and residual zinc ions to generate a zinc oxide film layer 400 covering the cavity surface 110 , which serves as a passivation film and / or an optical film of the laser chip 100 .

[0076] Please refer to Figure 5 , Figure 5 FIG. 1 is a schematic structural diagram of the laser chip 100 in which a zinc oxide film 400 is formed on the cavity surface 110 in step S106 .

[0077] Considering that some zinc ions will remain on the cavity surface 110 after the mixing is completed, in order to recycle the residual zinc ions, in this embodiment, an oxygen ion source is provided to react with the zinc ions to generate a zinc oxide film 400. The zinc oxide film 400 covers the cavity surface 110 as a passivation film and an optical film of the cavity surface 110, eliminating the need for subsequent additional growth of these two film layers, thereby greatly simplifying the preparation process.

[0078] Please continue reading Figure 1 , the semiconductor laser preparation method may further include:

[0079] Step S107 , when the quantum well layer 120 needs to be mixed again, the zinc oxide film layer 400 is ionized to generate zinc ions.

[0080] As the working time increases, the band gap in the window region gradually shrinks, and the band gap characteristics can be optimized by re-mixing the quantum well layer 120. In this case, no additional zinc source is required, and zinc ions can be ionized by ionizing the zinc oxide film layer 400 on the ionization chamber surface 110.

[0081] Specifically, in this embodiment, the laser of a preset wavelength band is used to vertically irradiate the cavity surface 110, and the laser zinc oxide film layer 400 is partially ionized to generate zinc ions. Preferably, the preset wavelength band is 1064 nm.

[0082] In summary, the semiconductor laser preparation method provided in this embodiment greatly shortens the diffusion path by diffusing zinc ions on the cavity surface 110, thereby significantly improving the quantum well intermixing efficiency and intermixing quality. In addition, the tedious steps of photolithography defining the window area and the non-window area on the side surface of the laser chip 100 and removing the mask layer after the window area grows first are eliminated, and the intermixing process can be performed after the laser chip 100 is systematically prepared and formed; the steps of additionally growing a passivation film and an optical film are also eliminated, and a zinc source can be provided for subsequent multiple quantum well intermixing repetitions, and the process is greatly simplified.

[0083] In addition, this embodiment also provides a semiconductor laser, which is manufactured by the aforementioned semiconductor laser manufacturing method.

[0084] It can be understood that the semiconductor laser structure provided in this embodiment is as follows Figure 5 As shown, the cavity surface 110 has a zinc oxide film layer 400 as its passivation film and optical film. Benefiting from the beneficial effects of the semiconductor laser manufacturing method, the semiconductor laser provided in this embodiment has the characteristics of better quality.

[0085] 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 modifications 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 preparing a semiconductor laser, characterized in that: include: Providing a laser chip (100); Placing the laser chip (100) in a vacuum environment at a preset temperature; Growing a zinc atomic layer (300) on the cavity surface (110) of the laser chip (100); Ionizing the zinc atomic layer (300) to generate zinc ions, so as to induce the zinc ions to diffuse from the cavity surface (110) to a region of the quantum well layer (120) of the laser chip (100) close to the cavity surface (110); An oxygen ion source and residual zinc ions are provided to generate a zinc oxide film layer (400) covering the cavity surface (110) to serve as a passivation film and / or an optical film of the laser chip (100).

2. The method for preparing a semiconductor laser according to claim 1, characterized in that: Before the step of placing the laser chip (100) in a vacuum environment at a preset temperature, the semiconductor laser preparation method further comprises: The surfaces of the P-side electrode and the N-side electrode of the laser chip (100) are respectively covered with high-temperature protection components (200).

3. The method for preparing a semiconductor laser according to claim 1, characterized in that: Before the step of placing the laser chip (100) in a vacuum environment at a preset temperature, the semiconductor laser preparation method further comprises: The portions of the metal layers on both sides of the laser chip (100) close to the cavity surface (110) are removed using the P-surface electrode and the N-surface electrode as boundaries.

4. The method for preparing a semiconductor laser according to claim 1, characterized in that: The step of growing a zinc atomic layer (300) on the cavity surface (110) of the laser chip (100) comprises: A zinc atomic layer (300) is grown on the cavity surface (110) by magnetron sputtering.

5. The method for preparing a semiconductor laser according to claim 1, characterized in that: The number of atomic layers of the zinc atomic layer (300) is between two and three; and / or, The thickness of the zinc atomic layer (300) is between 0.5 nm and 1.5 nm.

6. The method for preparing a semiconductor laser according to claim 1, characterized in that: The step of ionizing the zinc atomic layer (300) to generate zinc ions to induce the zinc ions to diffuse from the cavity surface (110) to a region of the quantum well layer (120) of the laser chip (100) close to the cavity surface (110) comprises: A negative bias voltage is applied to the substrate of the laser chip (100) to ionize the zinc atom layer (300) to generate zinc ions.

7. The method for preparing a semiconductor laser according to claim 1, characterized in that: After the step of providing an oxygen ion source and residual zinc ions to generate a zinc oxide film layer (400) covering the cavity surface (110) as a passivation film and / or an optical film of the laser chip (100), the semiconductor laser manufacturing method further comprises: When the quantum well layer (120) needs to be mixed again, the zinc oxide film layer (400) is ionized to generate zinc ions.

8. The method for preparing a semiconductor laser according to claim 7, characterized in that: The step of ionizing the zinc oxide film layer (400) to generate zinc ions comprises: The cavity surface (110) is vertically irradiated with laser light of a preset wavelength band to stimulate partial ionization of the zinc oxide film layer (400) and generate zinc ions.

9. A semiconductor laser, characterized in that: The semiconductor laser is prepared by the semiconductor laser preparation method according to any one of claims 1 to 8.

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