Method for treating semiconductor silicon wafer

Abstract

The present invention belongs to the technical field of semiconductors. Disclosed is a method for treating a semiconductor silicon wafer. The method comprises the following steps: cleaning a silicon wafer in deionized water and an organic solvent to remove contaminations and impurities on the surface thereof; preparing an oxide layer and a shielding layer on the surface of the silicon wafer; during a heat treatment, selectively stopping the spread and distribution of impurities by means of the effect of the shielding layer, such that only an unshielded region is subjected to a heat treatment, such that the impurities can be spread and distributed; first annealing, involving: returning the silicon wafer to a relatively good lattice structure by means of heating, eliminating stress and defects, and improving the quality and reliability of the wafer; and deposition, involving: by means of a physical or chemical vapor deposition method, depositing a dopant, a metal layer and a through hole filler on the surface of the silicon wafer, so as to form electrodes and a wire structure. Moreover, the method further comprises the steps of ion implantation, metallization and etching. In combination with the shielding layer technology, the present invention can effectively solve the problem of impurities, and can complete the heat treatment process for a silicon wafer.

Description

Semiconductor silicon wafer processing method Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and in particular relates to a semiconductor silicon wafer processing method. Background Art

[0002] Semiconductor silicon wafers, a core component of electronic devices, are thin slices made of high-purity silicon. In the semiconductor manufacturing process, silicon wafers undergo multiple processing and handling steps. First, high-purity silicon is extracted through chemical or physical methods. The silicon is then heated to high temperatures, melting it and forming large crystals, often called ingots. The ingots are then sliced ​​into thin slices, known as silicon wafers, using saws. Next, the wafers undergo surface cleaning and chemical treatment to remove surface impurities and improve quality. Cleaning and oxide layer removal are common steps. The wafers are then coated with thin films, such as silicon dioxide, to create specific structures and functions. This is achieved through techniques such as physical vapor deposition, chemical vapor deposition, and sputtering. Next, photolithography is used to transfer the chip design pattern onto the silicon wafer surface. This process uses techniques such as photomasks and ultraviolet light exposure to project the pattern onto the photosensitizer-coated silicon wafer. Finally, through etching, ion implantation, electroplating and other process steps, the pattern is transformed into a microstructure on the silicon wafer, forming conductive paths and various device structures. These steps are carried out according to the specific chip design and functional requirements. In summary, semiconductor silicon wafer processing involves multiple steps such as extracting high-purity silicon materials, ingot growth, cutting, surface treatment, thin film deposition, photolithography, etching, etc., and finally forming an integrated circuit chip with the required functions and structure.

[0003] When processing semiconductor silicon wafers, impurity problems occur in the etching, deposition, ion implantation and other processes, resulting in reduced silicon wafer quality. Therefore, how to reduce the impurity content is an urgent problem to be solved.

[0004] Summary of the Invention

[0005] In response to the problems existing in the prior art, the present invention provides a semiconductor silicon wafer processing method, which has the advantage of reducing the impurity content and solves the problem in the prior art that impurities have a significant impact on wafer quality.

[0006] The present invention is achieved by a method for processing a semiconductor silicon wafer, comprising the following steps:

[0007] Step S1, cleaning: cleaning the silicon wafer in deionized water and an organic solvent to remove surface pollutants and impurities;

[0008] Step S2, surface treatment: preparing an oxide layer and a shielding layer on the surface of the silicon wafer;

[0009] Step S3, heat treatment: During the heat treatment, the diffusion and distribution of impurities are selectively blocked by the shielding layer, and only the unshielded areas are heat treated, allowing the impurities to diffuse and distribute;

[0010] Step S4, first annealing: restoring the silicon wafer to a better lattice structure by heating, eliminating stress and defects, and improving wafer quality and reliability;

[0011] Step S5, deposition: depositing dopants, metal layers, and through-hole filling on the silicon surface by physical or chemical vapor deposition methods to form electrodes and wire structures;

[0012] Step S6, ion implantation: implanting the desired impurity ions into the silicon wafer, or heating the silicon wafer to a high temperature to diffuse the impurities into the interior of the silicon wafer, to form a PN junction and control the conductive properties;

[0013] Step S7, metallization: depositing a metal layer on the silicon surface by physical vapor deposition or electroplating for connecting circuits; Step S8, etching: using a chemical solution to locally etch the silicon surface to remove the shielding layer and form the required structure and holes.

[0014] As a preferred embodiment of the present invention, in step S2, the step of preparing the oxide layer and the shielding layer on the surface of the silicon wafer includes the following steps:

[0015] Step S21, oxidation: forming a silicon oxide film on the silicon surface by heating in an oxygen or water vapor environment;

[0016] Step S22, preparing a shielding layer: designing a mask pattern according to the area to be protected during the heat treatment, selecting a suitable mask material, and coating or depositing the mask material on the silicon oxide film to form a shielding layer.

[0017] As a preferred embodiment of the present invention, in step S2, the step of preparing the oxide layer and the shielding layer on the surface of the silicon wafer includes the following steps:

[0018] Step S23, preparing a shielding layer: using photolithography technology to define the area to be protected on the silicon surface, and depositing a shielding layer material thereon;

[0019] Step S24, oxidation: After the shielding layer is formed, a thermal oxidation method is used to make the silicon material react with oxygen to form a silicon oxide film on the surface.

[0020] As a preferred embodiment of the present invention, in step S22, the preparation of the shielding layer includes the following steps:

[0021] Step S221, designing a mask pattern: drawing a corresponding mask pattern in design software or on a device according to the area that needs to be protected during the heat treatment process;

[0022] Step S222, selecting a mask material: selecting a suitable mask material according to the desired shielding effect, impurity type, and ion implantation requirements;

[0023] Step S223, mask coating or deposition: using methods such as brush coating, spin coating, physical / chemical vapor deposition, etc., the selected mask material is evenly coated or deposited on the surface of the silicon wafer to ensure that the mask completely covers the area to be protected and forms a shielding layer of uniform thickness;

[0024] Step S224, second annealing: performing baking or annealing at an appropriate temperature and time according to the characteristics of the mask material and process requirements to improve the stability and adhesion of the mask layer.

[0025] As a preferred embodiment of the present invention, the shielding layer is a multi-layer mask structure of silicon nitride and silicon dioxide.

[0026] As a preferred embodiment of the present invention, the material of the shielding layer is one of tungsten-copper alloy and nickel-titanium alloy.

[0027] As a preferred embodiment of the present invention, in step S3, the heat treatment includes the following steps:

[0028] Heating process:

[0029] Step S31, placing the wafer in a heating device, such as a furnace or an annealing furnace;

[0030] Step S32, preheating the heating equipment to 300-350°C;

[0031] Step S33: Place the wafer in a preheating device and gradually heat the unshielded area to 700-730° C. by controlling the power and ventilation parameters of the heating device.

[0032] Insulation process:

[0033] Step S34, maintaining the wafer at a temperature of 700-730° C. for 35-45 minutes to achieve the desired diffusion and distribution effects, and based on the set temperature, the temperature is raised or lowered by 15° C. every 10 minutes;

[0034] Cooling process:

[0035] Step S35, gradually lowering the temperature in the heating device to start the cooling process, cooling by 20-25°C per minute from 0 to 10 minutes, cooling by 18-21°C per minute from 11 to 20 minutes, and cooling by 15°C per minute after 20 minutes.

[0036] As a preferred embodiment of the present invention, in step S6, the ion implantation step includes:

[0037] Step S61, cleaning: rigorously cleaning the silicon wafer to remove surface contaminants and residues;

[0038] Step S62, alignment: placing the silicon wafer in the ion implantation equipment and aligning it with the target area to ensure accurate positioning of the ion implantation;

[0039] Step S62, ion implantation: using a high-temperature diffusion method, controlling the annealing temperature and holding time to diffuse impurities when heated to a high temperature, and performing ion implantation, so that the wafer tilt angle and / or auxiliary strikeback voltage suppress the strikeback effect, ensuring the accuracy and uniformity of ion implantation.

[0040] As a preferred embodiment of the present invention, step S7 includes the following steps:

[0041] Step S71, physical vapor deposition: placing a silicon wafer in a physical vapor deposition device, activating a metal source, and utilizing the principles of vacuum and thermal evaporation to deposit a metal film on the silicon surface; Step S72, forming a metal layer: placing a silicon wafer as an anode in an electrolyte solution, and applying a forward voltage to cause metal ions to precipitate from the electrolyte and deposit on the wafer surface to form a metal layer.

[0042] As preferred in the present invention, the metal source is an aluminum target or a copper source.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] In the present invention, the cleaning step effectively removes contaminants and impurities from the silicon wafer surface, improving the wafer's purity. The surface treatment step creates an oxide layer and a shielding layer, enhancing the wafer's stability and electrical properties. The heat treatment step selectively controls the diffusion and distribution of impurities through the shielding layer, ensuring that only unshielded areas undergo heat treatment, thereby improving the wafer's quality. The first annealing step restores the silicon wafer's optimal lattice structure, eliminates stress and defects, and improves the wafer's quality and reliability. The deposition step deposits dopants, metal layers, and via filling on the silicon surface to form electrodes and conductor structures for circuit connection. The ion implantation step implants the desired impurity ions into the silicon wafer, or diffuses impurities into the interior of the wafer through heating, to form PN junctions and control conductivity. The metallization step deposits a metal layer (such as aluminum or copper) on the silicon surface to achieve circuit connection and conduction. The etching step uses a chemical solution to locally etch the silicon surface, removing the shielding layer and forming the desired structure and holes for further processing and manufacturing. These steps, combined with the shielding technology of the shielding layer, effectively address impurity issues and complete the silicon wafer's heat treatment process.

[0045] The advantages of the present process sequence are that the shielding layer provides additional protection, shielding specific areas or structures from the oxidation process. Oxidation is not required in the shielded areas, reducing the time and resources required for oxidation. This is suitable for the special requirements of some chips, such as those with specific areas that need to remain oxidation-free.

[0046] The shielding layer can be formed on the surface of the silicon wafer according to the design requirements, and plays a role in protecting certain areas and preventing the diffusion and distribution of impurities. At the same time, it also provides convenience and precise injection effects for subsequent ion implantation operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG1 is a flow chart of a method for processing a semiconductor silicon wafer according to an embodiment of the present invention;

[0048] FIG2 is a flow chart of a surface treatment process according to an embodiment of the present invention;

[0049] FIG3 is a flow chart of a surface treatment process according to another embodiment of the present invention;

[0050] FIG4 is a flowchart of a process for preparing a shielding layer according to an embodiment of the present invention;

[0051] FIG5 is a flow chart of a heat treatment process according to an embodiment of the present invention;

[0052] FIG6 is a flow chart of ion implantation according to an embodiment of the present invention;

[0053] FIG7 is a flow chart of metallization according to an embodiment of the present invention. DETAILED DESCRIPTION

[0054] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings.

[0055] The structure of the present invention is described in detail below with reference to the accompanying drawings.

[0056] 1 , a semiconductor silicon wafer processing method provided by an embodiment of the present invention includes the following steps:

[0057] Step S1, cleaning: cleaning the silicon wafer in deionized water and an organic solvent to remove surface pollutants and impurities;

[0058] Step S2, surface treatment: preparing an oxide layer and a shielding layer on the surface of the silicon wafer;

[0059] Step S3, heat treatment: During the heat treatment, the shielding layer selectively blocks the diffusion and distribution of impurities, and only the unshielded areas are heat treated, allowing the impurities to diffuse and distribute.

[0060] Step S4, first annealing: restoring the silicon wafer to a better lattice structure by heating, eliminating stress and defects, and improving wafer quality and reliability;

[0061] Step S5, deposition: depositing dopants, metal layers, and through-hole filling on the silicon surface by physical or chemical vapor deposition methods to form electrodes and wire structures;

[0062] Step S6, ion implantation: implanting the desired impurity ions into the silicon wafer, or heating the silicon wafer to a high temperature to diffuse the impurities into the interior of the silicon wafer, to form a PN junction and control the conductive properties;

[0063] Step S7, metallization: depositing a metal layer (such as aluminum or copper) on the silicon surface by physical vapor deposition or electroplating for connecting circuits;

[0064] Step S8, etching: using a chemical solution to locally etch the silicon surface, thereby removing the shielding layer and forming the desired structure and holes.

[0065] In the above embodiment, the cleaning step effectively removes contaminants and impurities from the silicon wafer surface, improving the wafer's purity. The surface treatment step forms an oxide layer and a shielding layer, enhancing the stability and electrical properties of the silicon wafer. The heat treatment step selectively controls the diffusion and distribution of impurities through the shielding layer, ensuring that only unshielded areas are heat-treated, thereby improving the wafer's quality. The first annealing step restores the silicon wafer's optimal lattice structure, eliminates stress and defects, and improves the wafer's quality and reliability. The deposition step deposits dopants, metal layers, and via filling on the silicon surface to form electrodes and conductor structures for circuit connection. The ion implantation step implants the desired impurity ions into the silicon wafer, or diffuses impurities into the interior of the silicon wafer through heating, to form PN junctions and control conductivity. The metallization step deposits a metal layer (such as aluminum or copper) on the silicon surface, achieving circuit connection and conduction. The etching step uses a chemical solution to locally etch the silicon surface, removing the shielding layer and forming the desired structures and holes for further processing and manufacturing. These steps, combined with the shielding technology of the shielding layer, effectively address impurity issues and complete the silicon wafer heat treatment process.

[0066] Referring to FIG. 2 , in one embodiment, in step S2 , the step of preparing an oxide layer and a shielding layer on the surface of a silicon wafer includes the following steps:

[0067] Step S21, oxidation: In an oxygen or water vapor environment, a silicon oxide film is formed on the silicon surface by heating; this silicon oxide film is used to isolate and protect the chip.

[0068] Step S22, preparing a shielding layer: designing a mask pattern according to the area to be protected during the heat treatment, selecting a suitable mask material, and coating or depositing the mask material on the silicon oxide film to form a shielding layer.

[0069] Oxidation and shielding layers can produce mutually reinforcing effects:

[0070] Silicon oxide film enhances shielding layer adhesion: As an insulating layer, silicon oxide film provides excellent isolation. The silicon oxide film formed during the oxidation process strengthens the adhesion between the shielding layer and the substrate. This helps ensure that the subsequent shielding layer is more firmly bonded to the silicon oxide film during chip manufacturing, reducing the risk of film delamination or separation.

[0071] Silicon oxide films facilitate shielding layer removal: Subsequent chip manufacturing processes may require the removal of portions of the shielding layer. Silicon oxide films provide superior protection, making shielding layer removal easier. By selecting appropriate chemical solutions or dry removal methods, the shielding layer can be removed without damaging the silicon oxide film.

[0072] Conversely, the presence of the shielding layer will also have a certain impact on the oxidation process. The shielding layer may slow down the oxidation rate or change the uniformity of oxidation, resulting in the formation of oxide layers of different thicknesses under the shielding layer.

[0073] Referring to Figure 3, in another embodiment, the preparation of the oxide layer and the shielding layer on the surface of the silicon wafer includes the following steps: Step S23, preparing the shielding layer: using photolithography technology to define the area to be protected on the silicon surface, and depositing the shielding layer material thereon; the shielding layer can be used to protect certain parts of the chip from being affected by the subsequent oxidation process.

[0074] Step S24, Oxidation: After the shielding layer is formed, thermal oxidation is used to react the silicon material with oxygen to form a thin silicon oxide film on the surface. The oxidation process covers the unshielded areas, while the shielded areas undergo little or no oxidation.

[0075] The advantages of this process sequence are that the shielding layer provides additional protection, shielding specific areas or structures from the oxidation process. Oxidation is not required in the shielded areas, reducing the time and resources required. This process is suitable for chips with special requirements, such as those with specific areas that need to remain oxidation-free.

[0076] Referring to FIG. 4 , in step S22 , the preparation of the shielding layer includes the following steps:

[0077] Step S221, designing a mask pattern: Draw a corresponding mask pattern in the design software or on the device based on the areas that need to be protected during the heat treatment process. These areas will be covered by a shielding layer to prevent impurity diffusion and distribution and facilitate subsequent ion implantation operations.

[0078] Step S222, selecting a mask material: selecting a suitable mask material based on the required shielding effect, impurity type, and ion implantation requirements. Commonly used mask materials include silicon nitride, silicon dioxide, and the like.

[0079] Step S223, mask coating or deposition: Use brush coating, spin coating, physical / chemical vapor deposition, etc. to evenly coat or deposit the selected mask material on the surface of the silicon wafer. Ensure that the mask completely covers the area to be protected and forms a shielding layer of uniform thickness.

[0080] Step S224, second annealing: performing baking or annealing at an appropriate temperature and time according to the characteristics of the mask material and process requirements to improve the stability and adhesion of the mask layer.

[0081] Through the above steps, a shielding layer is formed on the silicon wafer surface according to design requirements, protecting certain areas and preventing impurity diffusion and distribution. It also facilitates and ensures precise ion implantation in subsequent operations. During implementation, the parameters and conditions of each step need to be adjusted according to specific requirements.

[0082] For example, the appropriate baking or annealing temperature and time depend on the characteristics and requirements of the mask material, as well as the specific process. In specific implementation, the following parameters can be used:

[0083] 1. Silicon nitride (Si3N4) mask: baking temperature range is between 800℃ and 1100℃; baking time is between 30 minutes and 2 hours;

[0084] 2. Silicon dioxide (SiO2) mask: The baking temperature range is between 900°C and 1200°C; the baking time is between 30 minutes and 2 hours.

[0085] Preferably, the shielding layer is a multilayer mask structure of silicon nitride and silicon dioxide, which can further improve the shielding layer's anti-deformation performance. The multilayer structure can disperse thermal stress and absorb mechanical stress, reducing the risk of wafer deformation.

[0086] Preferably, the shielding layer is made of a tungsten-copper alloy or a nickel-titanium alloy. These materials not only serve as shielding layers but also address the problem of wafer deformation. These materials have high strength and excellent thermal stability, effectively reducing wafer deformation during heat treatment.

[0087] Referring to FIG5 , in step S3, the heat treatment includes the following steps:

[0088] Heating process:

[0089] Step S31, placing the wafer in a heating device, such as a furnace or an annealing furnace;

[0090] Step S32, preheating the heating equipment to 300-350°C;

[0091] Step S33: Place the wafer in a preheating device and gradually heat the unshielded area to 700-730° C. by controlling the power and ventilation parameters of the heating device.

[0092] Insulation process:

[0093] In step S34, the wafer is kept at a temperature of 700-730° C. for 35-45 minutes to achieve the desired diffusion and distribution effects, and the temperature is increased or decreased by 15° C. every 10 minutes based on the set temperature.

[0094] Cooling process:

[0095] Step S35, gradually lowering the temperature in the heating device to start the cooling process, cooling by 20-25°C per minute from 0 to 10 minutes, cooling by 18-21°C per minute from 11 to 20 minutes, and cooling by 15°C per minute after 20 minutes.

[0096] When slow cooling is used, the cooling rate can be gradually reduced to avoid sharp temperature differences causing chip deformation or stress to re-generate.

[0097] Referring to FIG. 6 , in step S6 , the ion implantation step includes:

[0098] Step S61, cleaning: The silicon wafer is rigorously cleaned to remove surface contaminants and residues using deionized water, organic solvents, or other cleaning methods.

[0099] Step S62, alignment: placing the silicon wafer in the ion implantation equipment and aligning it with the target area to ensure accurate positioning of the ion implantation.

[0100] Step S62, ion implantation: using a high-temperature diffusion method, controlling the annealing temperature and holding time to diffuse impurities when heated to a high temperature, and performing ion implantation, so that the wafer tilt angle and / or auxiliary strikeback voltage suppress the strikeback effect, ensuring the accuracy and uniformity of ion implantation.

[0101] It should be noted that by adjusting the implantation energy, the depth of ion implantation can be controlled. Ions with different energies will penetrate the surface and embed to a specific depth in the silicon wafer. Appropriate impurity types, such as boron (B), phosphorus (P), and germanium (Ge), are selected to form a specific PN junction or control conductivity. The required implantation energy range and energy magnitude, such as kiloelectronvolts (keV) or megaelectronvolts (MeV), are determined to control the depth of impurity ion implantation. Annealing can also be performed to further optimize the performance and structure of the wafer.

[0102] Referring to FIG. 7 , step S7 includes the following steps:

[0103] Step S71, physical vapor deposition: placing a silicon wafer in a physical vapor deposition device, activating a metal source, and utilizing the principles of vacuum and thermal evaporation to deposit a metal film on the silicon surface; Step S72, forming a metal layer: placing a silicon wafer as an anode in an electrolyte solution, and applying a forward voltage to cause metal ions to precipitate from the electrolyte and deposit on the wafer surface to form a metal layer.

[0104] Furthermore, the metal source is an aluminum target or a copper source.

[0105] Working principle of the present invention:

[0106] During use, the cleaning step removes contaminants and impurities, improving the purity of the wafer;

[0107] Surface treatment to prepare oxide layer and shielding layer to enhance the stability and electrical properties of the chip;

[0108] Thermal treatment selectively controls the diffusion and distribution of impurities through the shielding layer, improving wafer quality;

[0109] The first annealing eliminates stress and defects, restores the lattice structure, and improves wafer quality and reliability;

[0110] The deposition step deposits dopants, metal layers, and fills through-holes on the silicon surface to realize electrode and wire structures and achieve circuit connections;

[0111] Ion implantation injects the required impurities into the wafer or diffuses the impurities into the interior of the wafer to form a PN junction and control the conductive properties;

[0112] The metallization step achieves circuit connection and conduction on the silicon surface by depositing metal layers, such as aluminum and copper;

[0113] The etching step uses a chemical solution to locally etch the silicon surface, removing the shielding layer and forming the desired structure and holes for further processing and manufacturing. These steps, combined with shielding layer technology, effectively address impurity issues and complete the heat treatment process for silicon wafers.

[0114] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0115] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A semiconductor silicon wafer processing method, characterized in that: The following steps are involved: Step S1, cleaning: cleaning the silicon wafer in deionized water and an organic solvent to remove pollutants and impurities on the surface; Step S2, surface treatment: preparing an oxide layer and a shielding layer on the surface of the silicon wafer; Step S3, heat treatment: During the heat treatment, the diffusion and distribution of impurities are selectively blocked by the shielding layer, and only the unshielded area is heat treated to allow the impurities to diffuse and distribute; Step S4, first annealing: restore the silicon wafer to a better lattice structure by heating, eliminate stress and defects, and improve wafer quality and reliability; Step S5, deposition: depositing dopants, metal layers, and through-hole filling on the silicon surface by physical or chemical vapor deposition methods to form electrodes and wire structures; Step S6, ion implantation: implanting the required impurity ions into the silicon wafer, or heating the silicon wafer to a high temperature to diffuse the impurities into the silicon wafer, so as to form a PN junction and control the conductive properties; Step S7, metallization: depositing a metal layer on the silicon surface by physical vapor deposition or electroplating for connecting circuits; Step S8, etching: using a chemical solution to locally etch the silicon surface, the shielding layer can be removed and the desired structure and holes can be formed.

2. A semiconductor silicon wafer processing method as claimed in claim 1, characterized in that: In step S2, the step of preparing an oxide layer and a shielding layer on the surface of a silicon wafer comprises the following steps: Step S21, oxidation: forming a silicon oxide film on the silicon surface by heating in an oxygen or water vapor environment; Step S22, preparing a shielding layer: designing a mask pattern according to the area to be protected during the heat treatment process, and selecting a suitable mask material, coating or depositing the mask material on the silicon oxide film to form a shielding layer.

3. A semiconductor silicon wafer processing method as claimed in claim 1, characterized in that: In step S2, the step of preparing an oxide layer and a shielding layer on the surface of a silicon wafer comprises the following steps: Step S23, preparing a shielding layer: using photolithography technology to define the area to be protected on the silicon surface, and depositing a shielding layer material thereon; Step S24, oxidation: After the shielding layer is formed, a thermal oxidation method is used to make the silicon material react with oxygen to form a silicon oxide film on the surface.

4. A semiconductor silicon wafer processing method as claimed in claim 2, characterized in that: In step S22, the preparation of the shielding layer includes the following steps: Step S221, designing a mask pattern: drawing a corresponding mask pattern on a design software or device according to the area to be protected during the heat treatment process; Step S222, selecting a mask material: selecting a suitable mask material according to the required shielding effect, impurity type and ion implantation requirements; Step S223, mask coating or deposition: using brush coating, spin coating, physical / chemical vapor deposition and other methods, the selected mask material is uniformly coated or deposited on the surface of the silicon wafer to ensure that the mask completely covers the area to be protected and forms a shielding layer with uniform thickness; Step S224, second annealing: According to the characteristics of the mask material and the process requirements, baking or annealing treatment is performed at an appropriate temperature and time to improve the stability and adhesion of the mask layer.

5. A semiconductor silicon wafer processing method as claimed in claim 1, characterized in that: The shielding layer is a multi-layer mask structure of silicon nitride and silicon dioxide.

6. A semiconductor silicon wafer processing method as claimed in claim 1, characterized in that: The material of the shielding layer is one of tungsten copper alloy and nickel titanium alloy.

7. A semiconductor silicon wafer processing method as claimed in claim 1, characterized in that: In step S3, the heat treatment comprises the following steps: Heating process: Step S31, placing the wafer in a heating device, such as a furnace or an annealing furnace; Step S32, preheating the heating device to 300-350°C; Step S33, placing the wafer in a preheating device, and gradually heating the unshielded area to 700-730° C. by controlling the power and ventilation parameters of the heating device; Insulation process: Step S34, maintaining the wafer at a temperature of 700-730° C. for 35-45 minutes to achieve the desired diffusion and distribution effects, and based on the set temperature, the temperature is repeatedly increased or decreased by 15° C. every 10 minutes; Cooling process: Step S35, gradually lowering the temperature in the heating device to start the cooling process, cooling by 20-25°C per minute during 0-10 minutes, by 18-21°C per minute during 11-20 minutes, and by 15°C per minute after 20 minutes.

8. A semiconductor silicon wafer processing method as claimed in claim 1, characterized in that: In step S6, the ion implantation step includes: Step S61, cleaning: strictly cleaning the silicon wafer to remove surface contaminants and residues; Step S62, alignment: placing the silicon wafer in the ion implantation equipment and aligning it with the target area to ensure accurate positioning of the ion implantation; Step S62, ion implantation: using a high temperature diffusion method, controlling the annealing temperature and holding time to diffuse impurities when heated to a high temperature, and performing ion implantation, so that the wafer tilt angle and / or the auxiliary counter-attack voltage suppress the counter-attack effect, ensuring the accuracy and uniformity of the ion implantation.

9. A semiconductor silicon wafer processing method as claimed in claim 1, characterized in that: Step S7 includes the following steps: Step S71, physical vapor deposition: placing a silicon wafer in a physical vapor deposition device, activating a metal source, and utilizing the principles of vacuum and thermal evaporation to deposit a metal film on the silicon surface; Step S72, forming a metal layer: placing a silicon wafer as an anode in an electrolyte solution, applying a forward voltage to cause metal ions to precipitate from the electrolyte and deposit on the wafer surface to form a metal layer.

10. A semiconductor silicon wafer processing method as claimed in claim 9, characterized in that: The metal source is an aluminum target or a copper source.

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