Laser and manufacturing method thereof

Abstract

The invention relates to a laser manufacturing method, which comprises the following steps of S1, adopting an aluminum-containing semiconductor material as a butt-joint growth mask, and performing butt-joint growth; s2, after butt-joint growth is completed, removing the butt-joint growth mask containing aluminum in the reaction chamber; s3, after the butt-joint growth mask is removed, epitaxial growth continues to be carried out in the reaction chamber; and S4, after the epitaxial growth is finished, carrying out subsequent manufacturing to obtain the laser. The invention also provides a laser which is manufactured by the laser manufacturing method. According to the method, the aluminum-containing semiconductor material is used as the butt-joint growth mask, the performance and yield of the laser are improved, after butt-joint growth is completed, the aluminum-containing butt-joint growth mask is removed through in-situ corrosion in the reaction chamber, subsequent epitaxial growth is directly carried out, the wafer can be prevented from being exposed to the external environment in the transfer process by adopting the mode, and the yield of the laser is improved. Meanwhile, the method can be seamlessly connected with a material growth step, so that the process steps are reduced, and the process time is shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical communication technology, in particular to a laser and a manufacturing method thereof. BACKGROUND

[0002] The commonly used mask for butt joint growth of the current edge-emitting laser is SiO2 / SiNx, which forms an undercute as a mask layer, as shown in Figure 1 , which affects the accumulation of butt joint materials on the interface, forms growth defects of butt joint interface materials, and further affects the performance of the laser. Patent CN 117613663 B adopts MOCVD to epitaxially grow dense crystalline AlInAs, AlGaInAs, AlAs, AlGaAs and other aluminum-containing material layers, and obtains a dense amorphous epitaxial mask layer after oxidation. Crystal epitaxial growth cannot be performed on these amorphous AlInAs, AlGaInAs, AlAs, AlGaAs and other aluminum-containing material layers, while crystal epitaxial growth can be performed on other places. During MOCVD butt joint growth, there is no undercute effect, and there are few defects at the butt joint interface. After butt joint growth is completed, the wafer is taken out of the MOCVD reaction chamber, and the amorphous mask layer is removed by dry etching or wet etching in the external environment, and then buried growth of the InP cover layer and the contact layer is performed. This scheme removes the amorphous mask layer in the external environment, which is easy to introduce dirty particles in the environment, and may also cause oxidation of the surface material of the wafer. In order to remove the dirt and the oxidation layer, an additional wet treatment process needs to be introduced. SUMMARY

[0003] The present application aims to provide a laser and a manufacturing method thereof, which can at least solve some defects in the prior art.

[0004] To achieve the above object, the embodiments of the present application provide the following technical scheme: a laser manufacturing method, comprising the following steps:

[0005] S1, using an aluminum-containing semiconductor material as a butt joint growth mask, and performing butt joint growth;

[0006] S2, after the butt joint growth is completed, removing the aluminum-containing butt joint growth mask in the reaction chamber;

[0007] S3, after the aluminum-containing butt joint growth mask is removed, continuing epitaxial growth in the reaction chamber;

[0008] S4, after the epitaxial growth is completed, performing subsequent manufacturing to obtain a laser.

[0009] Further, the aluminum-containing semiconductor material is an aluminum-containing amorphous semiconductor material.

[0010] Further, after growing the aluminum-containing semiconductor material, the wafer is exposed to an oxygen-containing environment to oxidize the wafer into an amorphous semiconductor material.

[0011] Further, before S1, the aluminum-containing amorphous semiconductor material is first prepared, and then a photoresist is used as a mask or SiO2 / SiN x is used as a mask for the patterning process, and after the patterning process is completed, the mask is removed, and the aluminum-containing amorphous semiconductor material is used as a butt joint growth mask.

[0012] Further, the butt joint growth specifically includes sequentially growing an InP layer, an active layer, an InP layer, and a sacrificial layer, the sacrificial layer has the same thickness as the aluminum-containing amorphous semiconductor material, and the upper surface of the sacrificial layer is flush with the upper surface of the aluminum-containing amorphous semiconductor material; or sequentially growing a P-InP layer, an N-InP layer, and a sacrificial layer, the N-InP layer is flush with the lower surface of the aluminum-containing amorphous semiconductor material, the sacrificial layer has the same thickness as the aluminum-containing amorphous semiconductor material, and the upper surface of the sacrificial layer is flush with the upper surface of the aluminum-containing amorphous semiconductor material.

[0013] Further, one or more of a chloride, hydrogen chloride gas, a bromide, and hydrogen bromide gas is used to remove the butt joint growth mask.

[0014] Further, the aluminum-containing semiconductor material is AlGaInAs, AlInAs, AlAs, or AlGaAs.

[0015] Further, after the butt joint growth mask is removed, a cap layer and a contact layer are sequentially grown in the reaction chamber.

[0016] Further, subsequent fabrication includes ridge waveguide, isolation region, cleaving region, electrical injection window, and electrode fabrication, and processes such as thinning, sputtering, alloying, etc., and finally cleaving, film plating, and individualization to complete the fabrication of the laser.

[0017] An embodiment of the present application provides another technical solution: a laser is prepared by using the laser fabrication method described above.

[0018] Compared with the prior art, the present application has the following advantages: the aluminum-containing semiconductor material is used as a butt joint growth mask, and after butt joint growth, there is no influence of the gable roof structure and residual silicon oxide on the subsequent growth of the epitaxial material, thereby improving the performance and yield of the laser, and after the butt joint growth is completed, the aluminum-containing butt joint growth mask is removed in situ in the reaction chamber, and subsequent epitaxial growth is directly performed, which can avoid exposure of the wafer to the external environment during the transfer process, reduce the risk of contamination and oxidation, and seamlessly connect with the material growth step, thereby reducing the process steps and time. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The butt joint structure schematic diagram for traditional SiO2 / SiNx as mask;

[0020] Figure 2 The growth of aluminum-containing crystalline material structure schematic diagram of the laser manufacturing method provided by the embodiment of the present application;

[0021] Figure 3 The oxidation of aluminum-containing crystalline material into amorphous semiconductor material structure schematic diagram of the laser manufacturing method provided by the embodiment of the present application;

[0022] Figure 4 The photoresist as mask dry etching and wet etching structure schematic diagram of the laser manufacturing method provided by the embodiment one of the present application;

[0023] Figure 5 The aluminum-containing amorphous semiconductor material as mask structure schematic diagram of the laser manufacturing method provided by the embodiment one of the present application;

[0024] Figure 6 The aluminum-containing amorphous semiconductor material as mask, butt joint growth structure schematic diagram provided by the embodiment one of the present application;

[0025] Figure 7 The aluminum-containing amorphous semiconductor material in situ etching structure schematic diagram of the laser manufacturing method provided by the embodiment one of the present application;

[0026] Figure 8 The cap layer and contact layer growth structure schematic diagram provided by the embodiment one of the present application;

[0027] Figure 9 The traditional SiO2 / SiN x The mesa structure schematic diagram for mask;

[0028] Figure 10 The buried heterojunction structure schematic diagram for amorphous semiconductor material as mask of the laser manufacturing method provided by the embodiment two of the present application;

[0029] Figure 11 The buried heterojunction growth structure schematic diagram for amorphous semiconductor material as mask provided by the embodiment two of the present application;

[0030] Figure 12 The cap layer and contact layer growth structure schematic diagram after in situ etching aluminum-containing amorphous semiconductor material of the laser manufacturing method provided by the embodiment two of the present application;

[0031] In the drawing: 1-substrate; 2-InP layer; 3-active layer; 4-spacer InP layer; 5-grating layer; 6-grating buried InP layer; 8-aluminum-containing semiconductor material layer; 9-aluminum-containing amorphous semiconductor material; 10-photoresist; 11-bonded growth InP layer; 12-bonded growth active layer; 13-bonded growth InP layer; 14-sacrificial layer; 15-InP cover layer; 16-contact layer; 17-SiO2 / SiN x mask layer; 18-gable-shaped structure; 19-tiled epitaxial layer; 20-P-InP layer; 21-N-InP layer. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0033] Please refer to Figures 2 to 12 The embodiment of the present application provides a laser fabrication method, comprising the following steps: S1, using aluminum-containing semiconductor material as a bonded growth mask, and performing bonded growth; S2, after the bonded growth is completed, removing the bonded growth mask containing aluminum in the reaction chamber; S3, after the bonded growth mask is removed, continuing to perform epitaxial growth in the reaction chamber; S4, after the epitaxial growth is completed, performing subsequent fabrication to obtain a laser. Specifically, as shown in FIG. 1, the laser fabrication method comprises the following steps. Figure 1The traditional SiO2 / SiNx mask butt joint structure is shown in the schematic diagram, including SiO2 / SiNx mask layer 17 and eaves structure 18. The structure has undercut eaves structure, and the eaves structure morphology is easy to form butt joint interface material defects. In the embodiment, the aluminum-containing semiconductor material is oxidized into amorphous material by epitaxy technology to grow as a butt joint growth mask. The eaves structure morphology and residual silicon oxide do not affect the subsequent epitaxial material growth, thereby improving the performance and yield of the laser. After the butt joint growth is completed, the aluminum-containing butt joint growth mask is etched in situ in the reaction chamber, and the subsequent epitaxial growth is directly performed (i.e., the growth of the InP cap layer and the contact layer is directly performed). In this way, the material growth defects of the butt joint interface can be avoided, the wafer can be prevented from being exposed to the external environment during the transfer process, the pollution and oxidation risk can be reduced, and the material growth steps can be seamlessly connected, thereby reducing the process steps and time. Preferably, the aluminum-containing semiconductor material is an aluminum-containing amorphous semiconductor material. The aluminum-containing amorphous semiconductor material is prepared by: after growing the aluminum-containing semiconductor material, the MOCVD-grown aluminum-containing crystalline semiconductor material such as AlGaInAs or AlInAs or AlAs or AlGaAs is directly exposed to an oxygen-containing environment to be oxidized into an amorphous semiconductor material. The amorphous material cannot be epitaxially grown into a crystalline state, but other places can be epitaxially grown into a crystalline state. After the butt joint growth is completed, the butt joint growth mask and the sacrificial layer are etched in situ in the reaction chamber, so that the subsequent InP cap layer and contact layer are directly grown.

[0034] Please refer to Figures 2 to 12 Before S1, the aluminum-containing amorphous semiconductor material is prepared, and then the photoresist is used as a mask or SiO2 / SiN x is used as a mask for patterning. After the patterning is completed, the mask is removed, and the aluminum-containing amorphous semiconductor material is used as a butt joint growth mask. Preferably, the InP layer, the active layer, the InP layer, and the sacrificial layer are sequentially butt jointed, the thickness of the sacrificial layer is the same as that of the aluminum-containing amorphous semiconductor material, and the upper surface of the sacrificial layer is flush with the upper surface of the aluminum-containing amorphous semiconductor material; or the P-InP layer, the N-InP layer, and the sacrificial layer are sequentially butt jointed, the N-InP layer is flush with the lower surface of the aluminum-containing amorphous semiconductor material, the thickness of the sacrificial layer is the same as that of the aluminum-containing amorphous semiconductor material, and the upper surface of the sacrificial layer is flush with the upper surface of the aluminum-containing amorphous semiconductor material. The sacrificial layer is the surface layer, and the sacrificial layer material is InP or an aluminum-containing compound. When the aluminum-containing amorphous semiconductor material is etched in situ, the sacrificial layer material is etched synchronously.

[0035] Please refer to Figures 2 to 12The interface growth mask is removed by one or more of chloride, hydrogen chloride gas, bromide, and hydrogen bromide gas. The aluminum-containing semiconductor material is AlGaInAs, AlInAs, AlAs, or AlGaAs.

[0036] Referring to Figures 2 to 12 The interface growth refers to interface growth of the material along the waveguide direction. Alternatively, the interface growth can also refer to growth of the material on both sides of the waveguide to limit current injection.

[0037] The following is a specific implementation:

[0038] Example 1: InP layer 2, active layer 3, spacer InP layer 4, and grating layer 5 are grown on substrate 1 by MOCVD;

[0039] The grating is fabricated on the surface of the epitaxial layer by holographic and etching processes or electron beam and etching processes, and then the grating buried layer InP 6 is grown by metal organic chemical vapor deposition to fill the grooves on the grating surface and make the surface flat;

[0040] Then, AlGaInAs sacrificial layer 7 and crystalline AlGaInAs or AlInAs or AlAs or AlGaAs layer 8 are grown in sequence, as shown in Figure 2 , Figure 2 The structure of the aluminum-containing crystalline material is shown in the figure, including substrate 1, InP layer 2, active layer 3, spacer InP layer 4, grating layer 5, grating buried InP layer 6, and crystalline AlGaInAs or AlInAs or AlAs or AlGaAs layer 8;

[0041] The epitaxial wafer after growing the crystalline AlGaInAs or AlInAs or AlAs or AlGaAs layer 8 is exposed to an oxygen-containing environment for oxidation, so that the crystalline AlGaInAs or AlInAs or AlAs or AlGaAs is oxidized into amorphous semiconductor oxide material 9, as shown in Figure 3 , Figure 3 The structure of the aluminum-containing crystalline material oxidized into amorphous semiconductor material is shown in the figure, including substrate 1, InP layer 2, active layer 3, spacer InP layer 4, grating layer 5, grating buried InP layer 6, and amorphous AlGaInAs or AlInAs or AlAs or AlGaAs oxide layer 9;

[0042] After dry etching and wet etching to the substrate with photoresist 10 as a mask, as shown in Figure 4 , Figure 4The structure diagram of the example one after dry etching and wet etching with the photoresist as mask, including substrate 1, InP layer 2, active layer 3, grating buried InP layer 6, amorphous AlGaInAs or AlInAs or AlAs or AlGaAs oxide layer 9 and photoresist 10;

[0043] Remove the photoresist mask 10, and take the amorphous semiconductor material 9 as mask layer, see Figure 5 , Figure 5 The structure diagram of the example one with the amorphous semiconductor material as mask, including substrate 1, InP layer 2, active layer 3, grating buried InP layer 6, amorphous AlGaInAs or AlInAs or AlAs or AlGaAs oxide layer 9;

[0044] Use epitaxy technology to grow InP layer 11, active layer 12, InP layer 13 and AlGaInAs sacrificial layer 14 in turn on the butt joint growth area, wherein the upper surface of the AlGaInAs sacrificial layer 14 is flush with the upper surface of the amorphous semiconductor material 9, and the thicknesses of the two are equal, see Figure 6 , Figure 6 The structure diagram of the example one after butt joint growth with the amorphous semiconductor material as mask, including substrate 1, InP layer 2, active layer 3, grating buried InP layer 6, amorphous AlGaInAs or AlInAs or AlAs or AlGaAs oxide layer 9, butt joint growth InP layer 11, butt joint growth active layer 12, butt joint growth InP layer 13 and sacrificial layer 14.

[0045] In the epitaxy technology growth reaction chamber, use hydrogen chloride HCl to in-situ etch to remove the amorphous material 9 containing aluminum and the AlGaInAs sacrificial layer 14, see Figure 7 , Figure 7 The structure diagram of the example one after in-situ etching of the amorphous semiconductor material, including substrate 1, InP layer 2, active layer 3, grating buried InP layer 6, butt joint growth InP layer 11, butt joint growth active layer 12, butt joint growth InP layer 13;

[0046] After the in-situ etching reaction is completed, grow InP cap layer 15 and contact layer 16 in turn in the reaction chamber, see Figure 8 , Figure 8 The structure diagram of the example one after growing the cap layer and the contact layer, including substrate 1, InP layer 2, active layer 3, grating buried InP layer 6, butt joint growth InP layer 11, butt joint growth active layer 12, butt joint growth InP layer 13, InP cap layer 15 and contact layer 16.

[0047] After the epitaxial growth, ridge waveguide, isolation region, cleaving region, electrical injection window and electrode are made in turn, and the epitaxial wafer is thinned and sputtered, and finally, the wafer is cleaved and coated to complete the chip production.

[0048] In example two, the active layer 3, the Spacer InP layer 4 and the grating layer 5 are grown on the substrate wafer by epitaxy;

[0049] The grating is made on the surface of the grating layer by holographic and etching process or electron beam and etching process, and then the grating buried layer InP 6 is grown by metal organic chemical vapor deposition to fill the groove on the grating surface and make the surface flat, and then the crystalline semiconductor material layer of AlGaInAs or AlInAs or AlAs or AlGaAs is grown.

[0050] The epitaxial wafer with the grown crystalline AlGaInAs or AlInAs or AlAs or AlGaAs is exposed to an oxygen-containing environment for oxidation, so that the crystalline AlGaInAs or AlInAs or AlAs or AlGaAs is oxidized into amorphous semiconductor oxide material 9.

[0051] The SiO2 / SiNx mask layer is grown, and the pattern is transferred to the mask layer SiO2 / SiNx by photolithography, and then the traditional mesa structure is formed by combining dry etching and wet etching. Figure 9 , Figure 9 The mesa structure with the traditional SiO2 / SiNx mask for example two is shown in the figure, which includes the substrate 1, the mesa epitaxial layer 19 and the SiO2 / SiNx mask layer 17.

[0052] The SiO2 / SiNx mask layer 17 is removed, and the amorphous semiconductor material 9 is used as the mask layer. Figure 10 , Figure 10 The buried heterojunction structure with the amorphous semiconductor material as the mask for example two is shown in the figure, which includes the substrate 1, the mesa epitaxial layer 19 and the amorphous AlGaInAs or AlInAs or AlAs or AlGaAs oxide layer 9, and the P-InP layer 20, the N-InP 21 and the AlGaInAs sacrificial layer 14 are grown in turn by epitaxy, wherein the N-InP 21 is flush with the lower surface of the amorphous semiconductor material 9, the AlGaInAs sacrificial layer 14 has the same thickness as the amorphous semiconductor material 9 and is flush. Figure 11 , Figure 11 The buried heterojunction structure after growth with the amorphous semiconductor material as the mask for example two is shown in the figure, which includes the substrate 1, the mesa epitaxial layer 19, the amorphous AlGaInAs or AlInAs or AlAs or AlGaAs oxide layer 9, the P-InP 20, the N-InP 21 and the sacrificial layer 14.

[0053] In the epitaxial growth reaction chamber, after removing the amorphous material 9 containing aluminum and the AlGaInAs sacrificial layer 14 by in-situ etching with hydrogen chloride HCl, the cover layer InP 15 and the contact layer 16 are directly grown in the reaction chamber in sequence, as shown in Fig. 4. Figure 12 , Figure 12 For example two, after in-situ etching of amorphous semiconductor material, the schematic diagram of the growth structure of the cover layer and the contact layer, including the substrate 1, the mesa epitaxial layer 19, P-InP 20, N-InP 21, InP cover layer 15 and contact layer 16.

[0054] After epitaxial growth, the cleavage zone, the electro-injection window and the electrode are made in sequence, and the wafer is thinned by sputtering alloy, and finally the chip is made by stripping and coating, and the chip is made.

[0055] The whole process of the method is completed, and the amorphous semiconductor material containing aluminum is used as a butt joint growth mask. After butt joint growth, the gable-shaped structure and the residual silicon oxide have no effect on the subsequent epitaxial material growth, so as to improve the performance and yield of the laser. After the butt joint growth is completed, the amorphous semiconductor material containing aluminum and the sacrificial layer are removed in-situ in the epitaxial growth reaction chamber, and the InP cover layer and the contact layer are directly grown. In this way, the wafer can be prevented from being exposed to the external environment during the transfer process, and the pollution and oxidation risk can be reduced. At the same time, the material growth step can be seamlessly connected, and the process steps and time are reduced. In addition, the sacrificial layer is AlGaInAs, which can also be InP or InAlAs or AlAs, as long as the corresponding gas can be used to remove the amorphous material and the sacrificial layer.

[0056] Please refer to Figures 2 to 12 The embodiment of the application provides a laser which is prepared by the above method, and the performance and yield of the laser can be improved.

[0057] Although the embodiments of the application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the application, and the scope of the application is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a laser, characterized in that: The steps include: S1, using an aluminum-containing semiconductor material as a butt-joint growth mask and performing butt-joint growth; S2, after the butt-joint growth is completed, removing the aluminum-containing butt-joint growth mask in the reaction chamber; S3, after removing the butt growth mask, continuing the epitaxial growth in the reaction chamber; S4: After the epitaxial growth is completed, subsequent fabrication is performed to obtain a laser.

2. The laser manufacturing method according to claim 1, wherein: The aluminum-containing semiconductor material is an aluminum-containing amorphous semiconductor material.

3. The laser manufacturing method according to claim 2, wherein: After the aluminum-containing semiconductor material is grown, the epitaxial wafer is exposed to an oxygen-containing environment to be oxidized into an amorphous semiconductor material.

4. The laser manufacturing method according to claim 2, wherein: Before S1, the aluminum-containing amorphous semiconductor material is first prepared, and then a photoresist is used as a mask or SiO2 / SiN x The mask is patterned, and after the patterning is completed, the mask is removed, and the aluminum-containing amorphous semiconductor material is used as a butt-jointed growth mask.

5. The laser manufacturing method according to claim 2, wherein: The butt-jointing growth is specifically as follows: butt-jointing the growth of an InP layer, an active layer, an InP layer and a sacrificial layer in sequence, wherein the sacrificial layer has the same thickness as the aluminum-containing amorphous semiconductor material, and the upper surface of the sacrificial layer is flush with the upper surface of the aluminum-containing amorphous semiconductor material; or butt-jointing the growth of a P-InP layer, an N-InP layer and a sacrificial layer in sequence, wherein the N-InP layer is flush with the lower surface of the aluminum-containing amorphous semiconductor material, the sacrificial layer has the same thickness as the aluminum-containing amorphous semiconductor material, and the upper surface of the sacrificial layer is flush with the upper surface of the aluminum-containing amorphous semiconductor material.

6. The laser manufacturing method according to claim 1, wherein: The butt-jointed growth mask is removed by using one or more of chloride, hydrogen chloride gas, bromide, and hydrogen bromide gas.

7. The laser manufacturing method according to claim 1, wherein: The aluminum-containing semiconductor material is AlGaInAs, AlInAs, AlAs or AlGaAs.

8. The laser manufacturing method according to claim 1, wherein: After the butting growth mask is removed, a cap layer and a contact layer are grown in sequence in the reaction chamber.

9. The laser manufacturing method according to claim 1, wherein: Subsequent production includes the production of ridge waveguides, isolation regions, cleavage regions, electrical injection windows and electrodes, as well as thinning, sputtering, alloying and other processes, and finally striping, coating and individualization to complete the production of the laser.

10. A laser, characterized in that: The laser is manufactured by the laser manufacturing method according to any one of claims 1 to 9.

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