InP-based DFB semiconductor laser dissociation and passivation method

Abstract

The invention discloses an InP-based DFB semiconductor laser dissociation and passivation method which specifically comprises the following steps: step 1, an InP-based wafer is pretreated and then placed on a bar, the bar carries the wafer in an ultrahigh vacuum system, the treated wafer in the ultrahigh vacuum system is placed on a sample holder in an ultrahigh vacuum cavity, and the sample holder is placed on a substrate; gradually raising the temperature through the heating element, and keeping the constant temperature for a period of time so as to desorb the adsorption gas on the surface of the wafer; 2, transferring the wafer from the baking cavity to a reaction cavity by using a vacuum transfer system, and ensuring that an ultrahigh vacuum environment is kept in the transfer process; the invention relates to the technical field of semiconductor lasers, and in the invention, when a passivation coating process is carried out on the end face of a bar, different preparation methods are selected according to different materials, and different vacuum deposition methods of molecular beam epitaxy, ion source assisted electron beam evaporation, magnetron sputtering and ion beam sputtering are respectively selected according to different selected material sources.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor lasers, in particular to a method for dissociating and passivating an InP-based DFB semiconductor laser. Background Art

[0002] The demand for computing power for AI model training has increased dramatically, and the demand for data transmission rate has also increased accordingly. Silicon photonics systems are the core solution for data transmission in the latest generation of AI computing centers. In order to achieve higher transmission efficiency, it is necessary to further improve the output power and photoelectric conversion efficiency of InP-based high-power DFB semiconductor lasers. The end face dissociation of conventional InP-based DFB laser chips is carried out under atmospheric conditions, exposing the laser emission end face of the laser, and then performing an end face passivation process. Since the resulting process is carried out under atmospheric conditions, single crystal interfaces such as quantum wells that constitute the end face of the laser will be oxidized after contact with the atmosphere, and the oxidized interface will affect the working performance and reliability of the laser. In addition, the passivation materials and processes will also affect the performance of the laser, especially under high-power working conditions.

[0003] To this end, the present invention provides a method for dissociating and passivating an InP-based DFB semiconductor laser. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for dissociating and passivating an InP-based DFB semiconductor laser, which solves the problem that it is impossible to ensure that its wireless signal can fully cover this area without being interfered with by the signal.

[0005] To achieve the above objectives, the present invention is implemented by the following technical scheme: a method for dissociating and passivating an InP-based DFB semiconductor laser, specifically comprising the following steps:

[0006] Step 1: Place the InP-based wafer on a bar after pretreatment. The bar carries the wafer in an ultra-high vacuum system. In the ultra-high vacuum system, place the processed wafer on a sample rack in an ultra-high vacuum chamber. The temperature is gradually increased by a heating element and kept constant for a period of time to desorb the adsorbed gas on the wafer surface.

[0007] Step 2: Use a vacuum transfer system to transfer the wafer from the baking chamber to the reaction chamber, ensuring that an ultra-high vacuum environment is maintained during the transfer process;

[0008] Step 3: Introduce reaction gas and use dissociation technology to excite the reaction gas so that it dissociates and deposits on the wafer surface;

[0009] Step 4: The dissociated wafer is still kept in the vacuum system, and the bar is transferred to the deposition chamber to perform a passivation coating process on the end surface of the bar.

[0010] Preferably, in step 1, the temperature is gradually increased by a heating element and is controlled between 150° C. and 300° C., wherein the constant temperature time is controlled between 3 h and 20 h.

[0011] Preferably, the reaction gas in step three may be one of phosphine or arsine, and the dissociation technology may be one of laser, plasma or heat source.

[0012] Preferably, the material source selected for the passivation coating process on the end face of the bar in step 4 is ZnSe, ZnS, Ge, Al 2 O 3 In one of the methods, a molecular beam is formed in an ultra-high vacuum system using a cracking furnace, an electron gun, or an ion gun, so that the deposited passivation layer is a single crystal thin film.

[0013] Preferably, the material source selected for the passivation coating process on the end face of the bar in step 4 is Al 2 O 3 、SiO 2 、 2 O 5 、TiO 2 、ZrO 2 , HfO 2 In one of the methods, ion source assisted electron beam evaporation deposition technology is selected for passivation.

[0014] Preferably, when the material source selected for the passivation coating process on the end face of the bar in step 4 is one of a-Si, TaN and SiN, the passivation layer is deposited by using one of magnetron sputtering or ion beam sputtering.

[0015] The present invention provides a method for dissociating and passivating an InP-based DFB semiconductor laser. Compared with the prior art, the present invention has the following beneficial effects:

[0016] When the present invention performs a passivation coating process on the end face of the bar, different preparation methods are selected according to different materials, and different vacuum deposition methods such as molecular beam epitaxy, ion source assisted electron beam evaporation, magnetron sputtering, and ion beam sputtering are selected according to different selected material sources; the bar can be better protected, and its contact with the external environment is reduced during the process, and unnecessary oxidation or other chemical reactions are prevented. Therefore, the passivation coating can effectively protect the bar and the wafer therein, and maintain its stability and purity during the processing. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0018] The present application provides a method for dissociating and passivating an InP-based DFB semiconductor laser, which specifically comprises the following steps:

[0019] Step 1: Place the InP-based wafer on a bar after pretreatment. The bar carries the wafer in an ultra-high vacuum system. Place the processed wafer on a sample rack in an ultra-high vacuum chamber in the ultra-high vacuum system. The temperature is gradually increased by a heating element. The temperature is controlled between 150°C and 300°C and maintained at a constant temperature for a period of time, wherein the constant temperature time is controlled between 3h and 20h, so that the adsorbed gas on the wafer surface can be desorbed.

[0020] Step 2: Use a vacuum transfer system to transfer the wafer from the baking chamber to the reaction chamber, ensuring that an ultra-high vacuum environment is maintained during the transfer process;

[0021] Step 3: introducing a reaction gas, which may be one of phosphine or arsine, and exciting the reaction gas by laser, plasma or heat source to dissociate and deposit on the wafer surface;

[0022] Step 4: The dissociated wafer is still kept in the vacuum system, and the bar is transferred to the deposition chamber to perform a passivation coating process on the end surface of the bar.

[0023] In step 4, the material sources selected for the passivation coating process on the end face of the bar are ZnSe, ZnS, Ge, Al 2 O 3 In one of the above methods, a molecular beam is formed in an ultra-high vacuum system using a cracking furnace, an electron gun, or an ion gun to deposit a passivation layer that is a single crystal thin film. 2 O 3 For single crystal thin film, process innovation is carried out from key technical contents such as deposition rate, substrate temperature, source temperature, raw material form, and component ratio. InP will cause the release of P element when the substrate temperature is low. Therefore, high-temperature deposition is not possible. By adjusting other key process steps at a safe substrate temperature, a single crystal thin film with good quality can be obtained.

[0024] The material source selected for the passivation coating process on the end face of the bar in step 4 is Al 2 O 3 、SiO 2 、 2O 5 、TiO 2 、ZrO 2 , HfO 2 In one of the above methods, ion source assisted electron beam evaporation deposition technology is selected for passivation. Preparation of Al by ion source assisted electron beam evaporation deposition technology 2 O 3 、SiO 2 、 2 O 5 、TiO 2 、ZrO 2 , HfO 2 In addition to the key process of molecular beam epitaxy, the ion beam assisted technology is used to improve the film density of the passivation layer, adjust the composition ratio, refractive index and microscopic morphology. At the same time, it can achieve the alternate deposition of multiple layers of thin films, making the passivation function, and can also prepare optical thin films. To achieve the improvement of laser output power;

[0025] When the material source selected for the passivation coating process on the end face of the bar in step 4 is one of a-Si, TaN, and SiN, the passivation layer is deposited by magnetron sputtering or ion beam sputtering. Sputtering can achieve a completely O-free 2 Under the deposition environment, the passivation layer and the optical property layer are prepared.

[0026] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0027] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A method for dissociating and passivating an InP-based DFB semiconductor laser, characterized in that: The specific steps include: Step 1: Place the InP-based wafer on a bar after pretreatment. The bar carries the wafer in an ultra-high vacuum system. In the ultra-high vacuum system, place the processed wafer on a sample rack in an ultra-high vacuum chamber. The temperature is gradually increased by a heating element and kept constant for a period of time to desorb the adsorbed gas on the wafer surface. Step 2: Use a vacuum transfer system to transfer the wafer from the baking chamber to the reaction chamber, ensuring that an ultra-high vacuum environment is maintained during the transfer process; Step 3: Introduce reaction gas and use dissociation technology to excite the reaction gas so that it dissociates and deposits on the wafer surface; Step 4: The dissociated wafer is still kept in the vacuum system, and the bar is transferred to the deposition chamber to perform a passivation coating process on the end surface of the bar.

2. The method for dissociating and passivating an InP-based DFB semiconductor laser according to claim 1, characterized in that: In the step 1, the temperature is gradually increased by a heating element, and the temperature is controlled between 150° C. and 300° C., wherein the constant temperature time is controlled between 3 h and 20 h.

3. The method for dissociating and passivating an InP-based DFB semiconductor laser according to claim 1, characterized in that: The reaction gas in step three may be one of phosphine or arsine, and the dissociation technology may be one of laser, plasma or heat source.

4. The method for dissociating and passivating an InP-based DFB semiconductor laser according to claim 1, characterized in that: When the material source selected for the passivation coating process on the end face of the bar in step 4 is one of ZnSe, ZnS, Ge, and Al2O3, a molecular beam is formed in an ultra-high vacuum system using one of the technologies of a cracking furnace, an electron gun, and an ion gun, so that the deposited passivation layer is a single crystal thin film.

5. The method for dissociating and passivating an InP-based DFB semiconductor laser according to claim 1, characterized in that: When the material source selected for the passivation coating process on the end face of the bar in step 4 is one of Al2O3, SiO2, Ta2O5, TiO2, ZrO2, and HfO2, ion source assisted electron beam evaporation deposition technology is selected for passivation.

6. The method for dissociating and passivating an InP-based DFB semiconductor laser according to claim 1, characterized in that: When the material source selected for the passivation coating process on the end face of the bar in step 4 is one of a-Si, TaN and SiN, the passivation layer is deposited by using one of magnetron sputtering or ion beam sputtering.