Low-cost long-life semiconductor doped separation blade and preparation method thereof

Abstract

The invention belongs to the technical field of semiconductor processes, and particularly relates to a low-cost and long-life semiconductor doped separation blade and a preparation method thereof, and the method comprises the steps: S1, carrying out the surface pretreatment and surface cleaning of a wafer; and S2, depositing a silicon nitride film on the surface of the cleaned wafer. According to the method, a silicon nitride film is directly deposited on a used wafer or an unused original wafer, so that the waste wafer is recycled, the resource waste is reduced, and the influence of the surface doping concentration of the separation blade on the formal production blade is effectively reduced through the isolation effect of the silicon nitride film; the process method is simple in theory and easy to understand and implement. Different process technicians can flexibly adjust deposition parameters (such as temperature, pressure, time and the like) according to equipment conditions and process requirements of respective factories so as to ensure that the silicon nitride film meeting the process requirements is obtained. Due to the flexibility, the method has wide applicability and can adapt to semiconductor production lines of different scales and types.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor process, and in particular relates to a low-cost and long-life semiconductor doping baffle and a preparation method thereof. Background Art

[0002] A considerable number of baffles are required in the semiconductor high-temperature furnace tube doping process. Their main functions include improving the airflow stability inside the furnace tube, ensuring the consistency of the loading state of the formal production wafers, and preventing the airflow into the furnace tube from blowing directly to the surface of the formal production wafers.

[0003] At present, one method for preparing baffles is to directly use silicon original wafers as baffles. This method does not require special baffles and is simple to operate. However, during long-term impurity diffusion, impurities will diffuse into the silicon wafer. As the baffle is used for a long time, the doping concentration on its surface becomes higher and higher. The high surface doping concentration of the baffle affects the doping uniformity of the formally produced wafers. Another method for preparing baffles is to grow a layer of silicon dioxide film on the surface of the silicon wafer and then deposit a layer of silicon nitride film. Since impurities are not easy to diffuse in the silicon nitride film, the baffle prepared by this method can prevent the increase of the doping concentration on the surface of the baffle due to long-term doping diffusion. However, this method has many preparation process steps, and with long-term doping diffusion, the silicon nitride on the surface of the baffle is easy to fall off due to the corrosion of the oxide layer after multiple cleanings, and it cannot be used for a long time. Summary of the invention

[0004] The purpose of the present invention is to provide a low-cost, long-life semiconductor doping baffle and preparation method, so as to solve the technical problems that the baffle preparation method in the prior art has many process steps, and with long-term doping diffusion, the oxide layer is corroded after multiple cleanings, resulting in the silicon nitride on the surface of the baffle easily falling off, and cannot be used for a long time.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present application discloses a method for preparing a low-cost and long-life semiconductor doping barrier, comprising: S1: Wafer surface pretreatment and surface cleaning; S2: depositing a silicon nitride film on the front and back sides of the cleaned wafer respectively; the thickness of the silicon nitride film is 50nm to 100nm, and obtaining a semiconductor doping stopper.

[0006] Preferably, in S1, the wafer surface is pretreated by using HF acid to corrode the oxide layer on the wafer surface until the wafer surface is dehydrated.

[0007] Preferably, in S1, the surface cleaning is specifically: cleaning with a cleaning solution for 10 minutes, then rinsing with pure DI water for 10 minutes, and drying in hot nitrogen.

[0008] Preferably, the cleaning solution is a mixture of ammonia water, hydrogen peroxide and pure water.

[0009] Preferably, the mixing volume ratio of the ammonia water, hydrogen peroxide and pure water is 1:2:7 to 1:2:3.

[0010] Preferably, the cleaning liquid temperature is 60°C to 90°C.

[0011] Preferably, in S2, the deposition rate of the silicon nitride film is 1.0-2.0 nm / min.

[0012] Preferably, in S2, the deposition temperature of the silicon nitride film is 700°C to 800°C.

[0013] Preferably, the wafer includes an original wafer, a wafer with an oxide layer, and a doped wafer. It is proposed to directly deposit a layer of silicon nitride film on a used wafer or an unused original wafer. This innovation not only realizes the recycling and reuse of waste wafers and reduces resource waste, but also effectively reduces the impact of the doping concentration on the surface of the baffle on the formal production wafer through the isolation effect of the silicon nitride film. Silicon nitride material has become an ideal choice of thin film material due to its good chemical stability, thermal stability and mechanical strength.

[0014] In a second aspect, the present application discloses a low-cost and long-life semiconductor doping barrier, which is manufactured using any of the above-mentioned manufacturing methods.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a method for preparing a low-cost, long-life semiconductor doped baffle. A layer of silicon nitride film is directly deposited on a used wafer or an unused original wafer, which not only realizes the recycling and reuse of waste wafers and reduces resource waste, but also effectively reduces the influence of the doping concentration on the surface of the baffle on the formal production wafer through the isolation effect of the silicon nitride film. The process method is simple in theory and easy to understand and implement. Different process technicians can flexibly adjust the deposition parameters (such as temperature, pressure, time, etc.) according to the equipment conditions and process requirements of their respective factories to ensure that a silicon nitride film that meets the process requirements is obtained. This flexibility makes the method widely applicable and can adapt to semiconductor production lines of different scales and types. By recycling waste wafers, the preparation cost of the baffle is significantly reduced. At the same time, the demand for new wafers is reduced, which helps to ease the tension in the semiconductor material supply chain and reduce the exploitation of natural resources and damage to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 is a flow chart of the method of the present invention; Figure 2 A flowchart of a preparation method according to an embodiment of the present invention; Figure 3 This is a cross-sectional structural diagram of the baffle.

[0018] Wherein: 1-silicon nitride film; 2-wafer. DETAILED DESCRIPTION

[0019] 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.

[0020] 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.

[0021] 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.

[0022] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0023] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0024] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it 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 it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings: See also Figure 1 The present application discloses a method for preparing a low-cost and long-life semiconductor doping barrier, comprising the following steps: S1: Wafer surface pretreatment and surface cleaning; S2: depositing a silicon nitride film on the front and back sides of the cleaned wafer respectively; the thickness of the silicon nitride film is 50nm to 100nm, and obtaining a semiconductor doping stopper.

[0026] A layer of silicon nitride film is directly deposited on the used wafer or the unused original wafer to reduce the influence of the high surface doping concentration of the baffle during long-term use on the doping uniformity of the formal production wafer. At the same time, the used wafer can be recycled and reused to reduce production costs. The process method is simple in theory and easy to understand. Different process technicians can adjust it according to different equipment and process conditions. Following this method can obtain results that meet the process requirements, and it has a wide range of applications.

[0027] In some embodiments, see Figure 3 A method for preparing a low-cost and long-life semiconductor doping barrier comprises the following steps: S1: Wafer surface pretreatment and surface cleaning; Wafer surface pretreatment, specifically: using HF acid to corrode the oxide layer on the wafer surface until the wafer surface is dehydrated; S2: depositing a silicon nitride film on the front and back sides of the cleaned wafer respectively; the thickness of the silicon nitride film is 50nm to 100nm, and obtaining a semiconductor doping stopper.

[0028] This technology prepares the baffle by directly depositing a silicon nitride film on a silicon original wafer. This method can avoid the increase in surface concentration of the baffle after long-term doping diffusion. At the same time, the baffle can be used for a long time through multiple cleaning methods, thereby reducing production costs and increasing the service life of the baffle.

[0029] In some embodiments, a method for preparing a low-cost and long-life semiconductor doping barrier comprises the following steps: S1: Wafer surface pretreatment and surface cleaning; S2: depositing a silicon nitride film on the front and back sides of the cleaned wafer respectively; the thickness of the silicon nitride film is 50nm to 100nm, and obtaining a semiconductor doping stopper.

[0030] In S1, the surface cleaning is specifically: cleaning with a cleaning solution for 10 minutes, then rinsing with pure DI water for 10 minutes, and drying in hot nitrogen.

[0031] In some embodiments, the cleaning solution is a mixture of ammonia water, hydrogen peroxide and pure water.

[0032] Further preferably, the mixing volume ratio of the ammonia water, hydrogen peroxide and pure water is 1:2:7 to 1:2:3.

[0033] More preferably, the cleaning liquid has a temperature of 60°C to 90°C.

[0034] In some embodiments, a method for preparing a low-cost and long-life semiconductor doping barrier comprises the following steps: S1: Wafer surface pretreatment and surface cleaning; S2: depositing a silicon nitride film on the front and back sides of the cleaned wafer respectively; the deposition rate is 1.0-2.0 nm / min, the thickness of the silicon nitride film is 50 nm-100 nm, and a semiconductor doping stopper is obtained.

[0035] In some embodiments, a method for preparing a low-cost and long-life semiconductor doping barrier comprises the following steps: S1: Wafer surface pretreatment and surface cleaning; S2: depositing a silicon nitride film on the front and back of the cleaned wafer respectively; the deposition temperature of the silicon nitride film is 700° C. to 800° C.; the thickness of the silicon nitride film is 50 nm to 100 nm, and a semiconductor doping baffle is obtained.

[0036] Furthermore, the wafers described in the present application include original wafers, wafers with oxide layers, and doped wafers. By recycling waste wafers, the preparation cost of the baffles is significantly reduced. At the same time, the demand for new wafers is reduced, which helps to ease the tension in the semiconductor material supply chain and reduce the exploitation of natural resources and damage to the environment.

[0037] In some embodiments, in order to effectively improve the service life of the baffle, reduce the impact of the baffle on the doping uniformity of the formal production wafer during long-term diffusion, and reduce production costs, the present invention provides a low-cost and long-life semiconductor doping baffle preparation method, which can prepare the baffle by directly depositing a silicon nitride film on the surface of the wafer. The following technical solutions are used to achieve this: A method for preparing a semiconductor doping barrier with low cost and long life, see Figure 2 , including the following steps: S1, wafer surface pretreatment: the wafer uses an original wafer or a wafer with an oxide layer or a doped wafer. The surface pretreatment uses HF acid to etch the oxide layer on the surface of the clean wafer. The HF acid etching temperature is room temperature and the etching is performed until the wafer surface is dehydrated.

[0038] S2, wafer surface cleaning; the surface treatment is performed using a mixed cleaning solution of ammonia water, hydrogen peroxide and pure water, the volume ratio of which is 1:2:7 to 1:2:3, and the cleaning solution temperature is 60°C to 90°C.

[0039] S3, depositing a thin film on the wafer obtained in S2; the thin film deposition on the wafer is to deposit a layer of silicon nitride film on the front and back sides of the wafer, with a thickness of 50nm to 100nm.

[0040] Directly depositing a layer of silicon nitride film on a used wafer or an unused original wafer not only realizes the recycling and reuse of waste wafers and reduces resource waste, but also effectively reduces the impact of the doping concentration on the surface of the baffle on the formal production wafer through the isolation effect of the silicon nitride film; the process method is simple in theory and easy to understand and implement. Different process technicians can flexibly adjust the deposition parameters (such as temperature, pressure, time, etc.) according to the equipment conditions and process requirements of their respective factories to ensure that a silicon nitride film that meets the process requirements is obtained. This flexibility makes the method widely applicable and can adapt to semiconductor production lines of different sizes and types. By recycling waste wafers, the preparation cost of the baffle is significantly reduced. At the same time, the demand for new wafers is reduced, which helps to ease the tension in the semiconductor material supply chain and reduce the exploitation of natural resources and damage to the environment.

[0041] In some embodiments, a method for preparing a low-cost and long-life semiconductor doping barrier comprises the following steps: S1. The wafer is immersed in HF acid solution and corroded at room temperature to etch the oxide layer on the surface of the wafer until the surface of the wafer is dehydrated.

[0042] S2, cleaning the wafer obtained in S1, using a mixed cleaning solution of ammonia, hydrogen peroxide and pure water for 10 minutes, then rinsing with pure DI water for 10 minutes, and drying in hot nitrogen; Preferably, the volume ratio of the cleaning liquid is 1:2:7 to 1:2:3, and the temperature of the cleaning liquid is 60°C to 90°C.

[0043] S3, depositing a silicon nitride film on the surface of the wafer obtained in S2; Preferably, the thickness of the silicon nitride film is 50 nm to 100 nm, the deposition temperature is 700° C. to 800° C., and the deposition rate is (1.0 to 2.0) nm / min.

[0044] The method is simple in theory and easy to understand and implement. Different process technicians can flexibly adjust deposition parameters (such as temperature, pressure, time, etc.) according to the equipment conditions and process requirements of their respective factories to ensure that a silicon nitride film that meets the process requirements is obtained. This flexibility makes the method widely applicable and can adapt to semiconductor production lines of different sizes and types.

[0045] Example 1 S1. The wafer is immersed in HF acid solution and corroded at room temperature to etch the oxide layer on the surface of the wafer until the surface of the wafer is dehydrated.

[0046] S2, cleaning the wafer obtained in S1, using a mixed cleaning solution of ammonia, hydrogen peroxide and pure water for 10 minutes, the volume ratio of the cleaning solution is 1:2:7, the temperature of the cleaning solution is 90°C, and then rinsing with pure DI water for 10 minutes, and drying in hot nitrogen; S3. Depositing a silicon nitride film on the surface of the wafer obtained in S2, with a deposition temperature of 700° C., a deposition rate of 1.0 nm / min, and a silicon nitride film thickness of 50 nm.

[0047] Example 2 S1. The wafer is immersed in HF acid solution and corroded at room temperature to etch the oxide layer on the surface of the wafer until the surface of the wafer is dehydrated.

[0048] S2, cleaning the wafer obtained in S1, using a mixed cleaning solution of ammonia, hydrogen peroxide and pure water for 10 minutes, the volume ratio of the cleaning solution is 1:2:3, the temperature of the cleaning solution is 60°C, and then rinsing with pure DI water for 10 minutes, and drying in hot nitrogen; S3. Depositing a silicon nitride film on the surface of the wafer obtained in S2, with a deposition temperature of 800° C., a deposition rate of 2.0 nm / min, and a silicon nitride film thickness of 100 nm.

[0049] Example 3 S1. The wafer is immersed in HF acid solution and corroded at room temperature to etch the oxide layer on the surface of the wafer until the surface of the wafer is dehydrated.

[0050] S2, cleaning the wafer obtained in S1, using a mixed cleaning solution of ammonia, hydrogen peroxide and pure water for 10 minutes, the volume ratio of the cleaning solution is 1:2:4, the temperature of the cleaning solution is 70°C, and then rinsing with pure DI water for 10 minutes, and drying in hot nitrogen; S3. Depositing a silicon nitride film on the surface of the wafer obtained in S2, with a deposition temperature of 750° C., a deposition rate of 1.5 nm / min, and a silicon nitride film thickness of 70 nm.

[0051] Example 4 S1. The wafer is immersed in HF acid solution and corroded at room temperature to etch the oxide layer on the surface of the wafer until the surface of the wafer is dehydrated.

[0052] S2, cleaning the wafer obtained in S1, using a mixed cleaning solution of ammonia, hydrogen peroxide and pure water for 10 minutes, the volume ratio of the cleaning solution is 1:2:5, the temperature of the cleaning solution is 70°C, and then rinsing with pure DI water for 10 minutes, and drying in hot nitrogen; S3. Depositing a silicon nitride film on the surface of the wafer obtained in S2, with a deposition temperature of 750° C., a deposition rate of 1.5 nm / min, and a silicon nitride film thickness of 80 nm.

[0053] Example 5 S1. The wafer is immersed in HF acid solution and corroded at room temperature to etch the oxide layer on the surface of the wafer until the surface of the wafer is dehydrated.

[0054] S2, cleaning the wafer obtained in S1, using a mixed cleaning solution of ammonia, hydrogen peroxide and pure water for 10 minutes, the volume ratio of the cleaning solution is 1:2:5, the temperature of the cleaning solution is 90°C, and then rinsing with pure DI water for 10 minutes, and drying in hot nitrogen; S3. Depositing a silicon nitride film on the surface of the wafer obtained in S2, with a deposition temperature of 800° C., a deposition rate of 1.5 nm / min, and a silicon nitride film thickness of 65 nm.

[0055] In the semiconductor manufacturing process, doping baffles are key components used to protect non-doped areas during ion implantation or other doping processes to ensure the accuracy and uniformity of the doping process. However, traditional baffle preparation often faces two major challenges: first, after long-term use, the doping concentration on the surface of the baffle increases, which may contaminate or affect the doping quality of the formal production wafer; second, the cost of baffle preparation is high, especially when new wafers are used as raw materials, which increases the overall production cost. The method for preparing a low-cost and long-life semiconductor doping baffle disclosed in the present invention not only shows significant innovation at the technical level, but also has made important breakthroughs in economy and environmental protection. Specifically reflected in the following: 1) This application proposes for the first time to directly deposit a layer of silicon nitride film on a used wafer or an unused original wafer. This innovation not only realizes the recycling and reuse of waste wafers and reduces resource waste, but also effectively reduces the impact of the doping concentration on the surface of the barrier wafer on the formal production wafer through the isolation effect of the silicon nitride film. Silicon nitride material has become an ideal choice of thin film material due to its good chemical stability, thermal stability and mechanical strength.

[0056] 2) Process simplification and optimization: The method disclosed in this application is simple in theory, easy to understand and implement. Different process technicians can flexibly adjust deposition parameters (such as temperature, pressure, time, etc.) according to the equipment conditions and process requirements of their respective factories to ensure that a silicon nitride film that meets the process requirements is obtained. This flexibility makes the method widely applicable and can adapt to semiconductor production lines of different sizes and types.

[0057] 4) Cost-effectiveness and environmental friendliness: By recycling waste wafers, the cost of preparing the baffles is significantly reduced. At the same time, the demand for new wafers is reduced, which helps to ease the tension in the semiconductor material supply chain and reduce the exploitation of natural resources and damage to the environment.

[0058] This method is not only applicable to the preparation of semiconductor doping barriers, but can also be extended to other fields that require high-precision, low-cost, and environmentally friendly thin film materials, such as solar panels and microelectronic device packaging. Its successful implementation will promote the green transformation of the semiconductor manufacturing industry and drive the industry towards a more sustainable and efficient direction.

[0059] In summary, the low-cost, long-life semiconductor doped baffle preparation method proposed in the present invention achieves a dual improvement in economic and environmental benefits by innovating the use of raw materials and simplifying and optimizing the process flow. This method not only solves the technical difficulties in the preparation of traditional baffles, but also provides strong support for the green and sustainable development of the semiconductor manufacturing industry. In the future, with the continuous promotion and improvement of this method, it is expected to make greater contributions to the transformation and upgrading of the semiconductor industry and global environmental protection.

[0060] The above are only preferred embodiments of the present invention and are 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 low-cost and long-life semiconductor doping barrier, characterized in that: include: S1: Wafer surface pretreatment and surface cleaning; S2: depositing a silicon nitride film on the front and back sides of the cleaned wafer; The thickness of the silicon nitride film is 50nm-100nm, and a semiconductor doping stopper is obtained.

2. The method for preparing a low-cost and long-life semiconductor doping barrier according to claim 1, characterized in that: In S1, the wafer surface is pretreated, specifically: HF acid is used to corrode the oxide layer on the wafer surface until the wafer surface is dehydrated.

3. The method for preparing a low-cost and long-life semiconductor doping barrier according to claim 1, characterized in that: In S1, the surface cleaning is specifically: cleaning with a cleaning solution for 10 minutes, then rinsing with pure DI water for 10 minutes, and drying in hot nitrogen.

4. The method for preparing a low-cost and long-life semiconductor doping barrier according to claim 3, characterized in that: The cleaning solution is a mixture of ammonia water, hydrogen peroxide and pure water.

5. The method for preparing a low-cost and long-life semiconductor doping barrier according to claim 4, characterized in that: The mixing volume ratio of the ammonia water, hydrogen peroxide and pure water is 1:2:7 to 1:2:

3.

6. The method for preparing a low-cost and long-life semiconductor doping barrier according to claim 3, characterized in that: The cleaning liquid temperature is 60°C to 90°C.

7. The method for preparing a low-cost and long-life semiconductor doping barrier according to claim 1, characterized in that: In the step S2, the deposition rate of the silicon nitride film is 1.0-2.0 nm / min.

8. The method for preparing a low-cost and long-life semiconductor doping barrier according to claim 1, characterized in that: In the step S2, the deposition temperature of the silicon nitride film is 700°C to 800°C.

9. The method for preparing a low-cost and long-life semiconductor doping barrier according to claim 1, characterized in that: The wafers include original wafers, wafers with oxide layers and doped wafers.

10. A low-cost and long-life semiconductor doping barrier, characterized in that: The method is prepared by any one of claims 1 to 9.

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