42 results about "Silica membrane" patented technology

The invention relates to the technical field of sewage treatment, in particular to a metal sulfide nanoparticle slow-release activator for sewage treatment and a preparation method of the metal sulfide nanoparticle slow-release activator for sewage treatment. The surface of the core layer is coated with the porous silicon dioxide membrane shell layer; the citric acid modifier is loaded on a core-shell interface; according to the invention, metal sulfide (such as FeS, MoS2, WS2 and the like) micro-nano particles are used as a solid-phase slow-release activator, so that the core problem of a traditional homogeneous activation system is radically solved. Firstly, the metal sulfide exists in the form of a solid phase and can directly contact and react with permanganate without an additional dissolving step, so that the problem of complicated process operation caused by poor solubility of activating agents such as sulfite is thoroughly avoided, and the process of reclaimed water treatment is simplified. The problem of poor continuous oxidation effect of a traditional homogeneous system is thoroughly solved.

A method of estimating a breakdown voltage of a silicon dioxide film includes; generating breakdown voltage information associated with first test dies selected from among test dies, generating a breakdown voltage estimation model by updating a parameter of a neural network model based on the breakdown voltage information, applying test voltages to second test die selected from among the test dies and distinct from the first dies and receiving currents levels for current generated by the second test dies in response to the test voltages, wherein the test voltages have respective levels lower than levels of breakdown voltages for the first test dies, and estimating breakdown voltages of the second test dies using the breakdown voltage estimation model in relation to the currents levels.

The application provides a novel titanium-based sunlight control coated glass and a preparation method thereof. The preparation method comprises the following steps: preparing a first titanium dioxide film layer, a second silicon dioxide film layer and a third mutually doped titanium dioxide / titanium nitride film layer on the upper surface of the glass in a tin bath by using a chemical vapor deposition method. The titanium dioxide film layer is used as a metal bridge for increasing the bonding capacity of the silicon dioxide film layer and the glass, and forms a double-layer antireflection layer together with the silicon dioxide film layer, so as to reduce the overall reflectivity and reflection interference color of the film layer. The mutually doped titanium dioxide / titanium nitride film layer is used for selectively absorbing visible light and solar energy, so as to reduce the transmittance of the visible light and the solar energy.

The application belongs to the field of coating technology, and relates to a laser protective lens high-damage threshold coating method based on a semiconductor wafer process, comprising the following steps: sequentially performing ultrasonic cleaning and plasma activation on an optical lens substrate to obtain a pretreated lens; alternately depositing hafnium dioxide film layers and silicon dioxide film layers on the surface of the pretreated lens by using a double-target co-sputtering process to obtain a coated lens; using trimethylaluminum and ozone as precursors, growing an aluminum oxide packaging layer on the surface of the coated lens by using an atomic layer deposition process, and then performing gradient annealing treatment to obtain a laser protective lens. The whole process is systematically optimized from interface bonding, film layer structure to surface packaging. Through the synergistic effect of optimizing each link of the coating process, the intrinsic quality of the film layer is improved while the environmental adaptability is enhanced, so that the lens can withstand long-term irradiation of high-power laser, and the damage resistance and long-term stability of the laser protective lens are significantly improved.

The application relates to a preparation method of a high-quality large-thickness silicon dioxide film layer, and belongs to the technical field of silicon-based photonic device preparation. The application aims to solve the problem that the large thickness and the high-quality and high-performance film layer cannot be considered simultaneously in the prior art, and provides a preparation method of a high-quality large-thickness silicon dioxide film layer; the method combines a dry-wet oxidation process and high-temperature annealing, designs part of the dry oxygen and the annealing process while the dry-wet-dry process is reformed, and can improve the quality and the light binding property of the large-thickness silicon dioxide film layer while the growth rate is maintained.

The invention belongs to the technical field of semiconductor device manufacturing processes, and relates to a slide glass wafer for SiC wafer rapid annealing, a preparation method and application, and the method comprises the steps: depositing a silicon dioxide film layer on a first silicon wafer and a second silicon wafer, and forming an etching masking layer; removing the second silicon wafer, performing dry etching on the first silicon wafer, and forming a groove corresponding to the second silicon wafer on the surface of the first silicon wafer; the first silicon wafer subjected to dry etching is put into an HF solution to be corroded so as to remove the etching masking layer, cleaning and drying are carried out, a slide wafer is obtained, the temperature measurement problem of the SiC wafer is solved in a slide wafer machining mode, low-cost machining of rapid annealing of the SiC wafer is achieved, and the temperature measurement efficiency of the SiC wafer is improved. The problems that traditional silicon-based rapid annealing equipment cannot accurately measure the surface temperature of the SiC wafer and rapid annealing of the SiC wafer is difficult to complete are solved.

This invention relates to a catalytic membrane for HCl oxidation reaction, the preparation method of which includes: Step 1: reacting silica particles with SiO2. ­2 A mixture of ZrO2 sol and silica gel is coated onto a hollow fiber carrier and calcined to obtain a transition layer for the membrane. Step two: A silsesquioxane sol is applied to the transition layer obtained in step one and calcined to obtain a silica membrane. Step three: The silica membrane obtained in step two is subjected to impurity removal treatment. Step four: A solution of silane coupling agent (A) and a metal salt solution (B) are prepared separately and mixed to obtain solution C. The silica membrane treated in step three is immersed in solution C and grafted with nano-metal particles using ultrasonic assistance, followed by a high-temperature reaction to obtain a catalytic membrane. The catalytic membrane designed in this invention, when applied to the HCl oxidation reaction, can separate reactants and products simultaneously, causing the reaction to shift forward, increasing the reaction conversion rate, reducing the reaction temperature, and extending the catalyst lifetime.

The invention relates to the technical field of microfluidic treatment, in particular to a nucleic acid microfluidic treatment system and method. Comprising a clamping box and an injector, the clamping box comprises a clamping plate seat and a clamping plate, the clamping plate is clamped in the clamping plate seat, the injector is clamped on the clamping plate seat, a plurality of rotary plug valves, ion exchange columns and silica gel membrane exchange columns are arranged in the clamping box, corresponding rotary valve heads are arranged on the clamping plate seat corresponding to different rotary plug valves, and the rotary valve heads are connected with the clamping plate seat. Each rotary valve head is correspondingly provided with one rotary valve motor, and different interfaces of the corresponding rotary plug valves are switched to be communicated through rotation of the rotary valve motors, so that a solution flows through the ion exchange column or the silica membrane exchange column, and switching of different plasmid purification modes is realized; the conversion of various purification modes is realized.

The embodiment of the present application provides a hard mask pattern manufacturing method and a DRAM capacitor manufacturing method, relates to the technical field of semiconductors, and can not only avoid the influence of long-time etching of polycrystalline silicon on the pattern of an insulating film, but also avoid damaging an existing metal layer and affecting the function of the metal layer in a substrate when etching a titanium dioxide film alone. The hard mask pattern manufacturing method comprises the following steps: providing a semiconductor substrate, the substrate being provided with a layer to be etched; forming a hard mask layer on the layer to be etched, the hard mask layer comprising, from bottom to top, a polycrystalline silicon film, a titanium dioxide film and a silicon dioxide film; and performing a patterning treatment on the hard mask layer to obtain a hard mask pattern.

The invention discloses a preparation method of a photon chip integrated microfluidic channel based on chemical mechanical polishing. Comprising the following steps: plating a silicon dioxide film on a thin-film lithium niobate photon chip by chemical vapor deposition, plating a chromium film by magnetron sputtering, directly writing a chromium mask by femtosecond laser, chemically and mechanically polishing, grinding and etching a microfluidic channel structure, carrying out wet etching on the mask, packaging with an ultraviolet curing adhesive and the like. According to the method disclosed by the invention, chemical mechanical polishing etching is used for replacing traditional photoetching, and the ultra-precision machining advantage of chemical mechanical polishing and the technical characteristics of low cost, high efficiency and the like of the femtosecond laser direct writing mask are utilized, so that a high-precision and low-roughness two-dimensional complex microfluidic channel structure can be prepared on a photon chip on a large scale; the method can be applied to the fields of on-chip optical fluid sensing, photochemical analysis, environment monitoring and the like.

The invention discloses a sensor for measuring various gases and a preparation method thereof, and the sensor comprises a main controller, a substrate, a silicon dioxide film layer arranged on the substrate, and a plurality of gas-sensitive sensing assemblies arranged on the silicon dioxide film layer in an array. Each gas-sensitive sensing assembly in the plurality of gas-sensitive sensing assemblies correspondingly detects at least one preset type of gas; wherein each gas-sensitive sensing assembly comprises a heating layer, and the heating layer is used for locally heating the gas-sensitive sensing assembly under the control of the main controller, so that the gas-sensitive sensing assembly works within a preset temperature; the electrode layer is used for transmitting induced current to the main controller; the induction layer is arranged on the electrode layer and is used for generating the induction current according to the gas; and the water vapor suppression layer is arranged on the induction layer and is used for enabling water vapor to be separated from the induction layer so as to increase the contact area between the induction layer and air. Therefore, various special gases can be accurately monitored.

This invention provides a surface passivation structure for a TVS diode, comprising a glass layer in a mesa-shaped region on one or both sides of a silicon substrate; a protective layer is constructed between the silicon substrate and the glass layer, the protective layer comprising at least a polycrystalline silicon film layer, and silicon dioxide films are constructed between the polycrystalline silicon film layer and the silicon substrate, and between the polycrystalline silicon film layer and the glass layer. A fabrication process for the TVS diode surface passivation structure is also proposed. This invention provides a TVS diode surface passivation structure, a dual passivation protection structure that completely isolates the device from the external environment, ensuring excellent high reliability, chemical stability, and high-temperature characteristics; simultaneously, this structure exhibits low leakage current and high conductivity, maximizing IPP capability and reducing the influence of surface electric fields.

Semiconductor devices having nanosheet architectures, e.g., transistors such as horizontal gate-all-around (hGAA) structures, methods, and apparatuses for forming such semiconductor devices are described. The methods comprise forming a cladding material around each of a first plurality of nanosheets; oxidizing a portion of the cladding material to form an oxidize film, such as a silicon oxide (SiO2) film, around the cladding material and a form a second plurality of nanosheets; annealing the second plurality of nanosheets at a temperature of less than or equal to 850° C.; and removing the oxide film.

This invention discloses a centrifugal microfluidic chip and a nucleic acid extraction method, specifically relating to the field of nucleic acid extraction technology. The method includes a pretreatment filtration module and a nucleic acid extraction and purification module. The sample solution undergoes primary and secondary filtration in the pretreatment filtration module to remove particulate impurities and protein precipitates, obtaining a clear sample supernatant. Nucleic acids in the supernatant are captured by a silica membrane in the nucleic acid extraction and purification module. Subsequently, a first washing solution and a second washing solution flow sequentially through the silica membrane to wash the adsorbed nucleic acids, removing residual impurities and reaction inhibitors. Finally, the eluent flows through the silica membrane, carrying the nucleic acids into the nucleic acid collection chamber, thereby obtaining the purified nucleic acid sample. This invention features a simple structure and reliable control, enabling sequential control of liquids in multiple chambers, effectively removing impurities and inhibitors from the sample, improving nucleic acid extraction efficiency and purity, and achieving a high degree of integration and automation in the nucleic acid extraction process for soil samples.

The invention discloses an etchant solution for a doped structure of a medium-low voltage MOS device, and relates to the technical field of semiconductors. Comprising chromic acid solution, hydrofluoric acid and nitric acid; x is the volume of hydrofluoric acid, y is the volume of the chromic acid solution, z is the volume of nitric acid, and the unit is mL; the ratio of x to y to z is (1: 1: 6)-(1: 1: 10). Chromic acid and HF further react to generate dichromic acid with higher oxidability, and the dichromic acid directly reacts with silicon, so that a highly-doped N-type region has a higher reaction rate, and the region is preferentially corroded to form a recess; the nitric acid oxidizes the silicon surface to generate a layer of ultra-thin silicon dioxide film, and the hydrofluoric acid efficiently dissolves the SiOO film generated by oxidation of the nitric acid, so that the pure silicon surface below is exposed, the pure silicon surface can be oxidized again, and the P-type region and the low-doped N-type region are circularly corroded. While the boundary of each doped region is ensured to be clearly displayed, the overall corrosion reaction time is effectively shortened, a fine device structure is protected from being excessively damaged in the process, and the process analysis efficiency is greatly improved.

Semiconductor devices having nanosheet architectures, e.g., transistors such as horizontal gate-all-around (hGAA) structures, methods, and apparatuses for forming such semiconductor devices are described. The methods comprise forming a cladding material around each of a first plurality of nanosheets; oxidizing a portion of the cladding material to form an oxidize film, such as a silicon oxide (SiO2) film, around the cladding material and a form a second plurality of nanosheets; annealing the second plurality of nanosheets at a temperature of less than or equal to 850 °C; and removing the oxide film.

The invention relates to a surface treatment process method for preparing a silicon carbide material by a CVD (Chemical Vapor Deposition) method, which comprises the following steps: placing the silicon carbide material prepared by the CVD method in an oxidation furnace, and carrying out oxidation treatment to form an oxide layer on the surface of the silicon carbide material; and removing the oxide layer. The oxidation treatment comprises the following steps: introducing oxygen, heating to a first preset temperature from room temperature at a speed of 3-5 DEG C / min, and carrying out heat preservation treatment; continuously raising the temperature to a second preset temperature at the speed of 2-3 DEG C / min, then raising the temperature to a target process temperature at the speed of 0.8-1.2 DEG C / min, and carrying out heat preservation oxidation; and the temperature is reduced to the first preset temperature at the speed of 2.5-3.5 DEG C / min, then is reduced to the third preset temperature at the speed of 1.3-1.8 DEG C / min, and finally is naturally reduced. A silicon carbide material is treated through an oxidation process, a defect layer is uniformly oxidized, an oxide layer (silicon dioxide film) is formed on the surface of the silicon carbide material, and then the oxide layer is removed, so that surface defects are eliminated, the service life of the SiC material is remarkably prolonged, and the stability and yield of the etching process are remarkably improved.

The tipping paper comprises a base material layer, an aluminum foil barrier layer is arranged on the outer side of the base material layer, a double-layer pearlescent ink layer is arranged on the outer side of the aluminum foil barrier layer, and the double-layer pearlescent ink layer comprises a pearlescent substrate layer arranged on the outer side of the aluminum foil barrier layer and a reinforced color-changing layer arranged on the outer side of the pearlescent substrate layer. A transition bonding layer is arranged on the outer side of the double pearlescent ink layers, a release layer is arranged on the outer side of the transition bonding layer, a micropore structure is arranged on the surface of the release layer, a silicon dioxide film layer is arranged on the outer side of the release layer, and a polypropylene film layer is arranged on the outer side of the silicon dioxide film layer. Through precise protection of the aluminum foil barrier layer and the pearlescent ink layer, interference of external moisture and temperature on color change is isolated, dynamic color development is achieved through the pearlescent ink layer, and the defect that traditional cigarette paper is prone to being affected by the environment is overcome.

The application relates to a glass storage bottle and a preparation method thereof, and is characterized in that: (1) brown glass bottles are cleaned by using water, an alkaline cleaning solution and an acidic cleaning solution, and then dried for standby use; (2) a layer of titanium dioxide film is plated on the inner surface and the outer surface of the brown glass bottles by using a dipping method / spraying method, and then dried at 80-120 DEG C; (3) a layer of silicon dioxide film is continuously plated on the titanium dioxide film layer by using the dipping method, and then dried at 80-120 DEG C; (4) the brown glass bottles plated with the film layers are solidified at 350-550 DEG C for 5-20 min, cooled and cleaned; the application has the beneficial effects that the preparation method is simple, the conditions are mild, the quality of the prepared film layers is relatively stable, the bonding force and the thickness of the film layers are improved, and the application is suitable for deep processing of the glass bottles.

This invention relates to the field of titanium dioxide. To address the problem that while titanium dioxide fillers improve the dielectric constant of ceramics, the coefficient of thermal expansion also increases simultaneously, a method for preparing low-thermal-expansion titanium dioxide fillers for ceramics is provided. The method includes: S100, under heating conditions, adding a doped ion solution to a titanium dioxide precursor solution to obtain a gel; the doped ion solution includes: Mo... 6+ and Sn 2+ Mo 6+ With Ti 4+ The molar ratio of Sn is (10-30):(1-2). 2+ With Ti 4+ The molar ratio is (10-20):(2-3); S200, the gel is calcined to obtain a preproduct; S300, the preproduct is coated with a film layer to obtain titanium dioxide filler; the film layer includes: a silica layer. This invention, by coating a film layer onto the outer surface of titanium dioxide, can utilize the film layer to limit the expansion of titanium dioxide at low temperatures, reducing the possibility of structural defects caused by differences in the thermal expansion of the raw materials; by coating titanium dioxide with a silica film layer, the expansion of titanium dioxide can be limited.

A method for making a dense organosilicon film with improved mechanical properties includes the steps of: providing a substrate within a reaction chamber; introducing into the reaction chamber a gaseous composition comprising alkoxysilane; and applying energy to the gaseous composition comprising alkoxysilane in the reaction chamber to induce reaction of the gaseous composition comprising alkoxysilane to deposit an organosilicon film on the substrate, wherein the organosilicon film has a dielectric constant of from ~ 2.40 to ~ 3.20, an elastic modulus of from ~ 6 to ~ 30 GPa, and an at. % carbon of from ~ 10 to ~ 45 as measured by XPS.

This invention belongs to the field of inorganic chemical technology, specifically relating to a highly efficient catalytic synthesis method for hydrogen bromide. It aims to solve technical problems such as high energy consumption, easy catalyst deactivation, and low purity. This invention involves mixing hydrogen gas with vaporized bromine vapor at a specific molar ratio; introducing the mixed gas into a catalytic reaction zone, where it contacts a core-shell structured catalyst and undergoes a blue LED catalytic reaction. The core-shell structured catalyst comprises a noble metal core and a corrosion-resistant metal oxide shell; after the catalytic reaction, a primary condensation process is performed to remove the bromine... 2 The hydrogen is liquefied and recovered, then separated using a zirconia-doped silica membrane for secondary membrane separation and recycling, yielding high-purity hydrogen bromide. This invention achieves near-complete conversion of bromine, high-purity products, and reduces bromine resource waste and environmental pollution through a closed-loop design.

The invention discloses a method for coloring the surface of an ornament. The method comprises the following steps: pretreatment; depositing a bottom film layer; depositing a silicon dioxide film layer; and evaporating an anti-fingerprint film layer. According to the method, the ruthenium oxide or iridium oxide thin film is pre-deposited on the surface of the brass ornament through the ALD atomic layer deposition technology to form the bottom film layer, then the SiO2 functional film layer is deposited on the basis of the bottom film layer, and finally the fingerprint-proof thin film is deposited on the surface of the brass ornament through the perfluoro modified silane and the vacuum evaporation technology. A uniform, stable, wear-resistant and corrosion-resistant ancient golden yellow film layer is obtained on the surface of the ornament, the ornament has excellent smoothness and smudginess resistance, the decoration effect and wearing experience of the ornament are remarkably improved, and the problems that in the prior art, a film layer is poor in color, weak in binding force, poor in corrosion resistance, insufficient in antifouling property and the like are solved.

The present application relates to the technical field of gas separation material, and more particularly to a polysilsesquioxane gas separation membrane, a preparation method and application thereof, the polysilsesquioxane gas separation membrane comprises an alpha-Al2O3 support body, an alpha-Al2O3 particle layer, a transition layer and a polysilsesquioxane layer, and the preparation raw material of the polysilsesquioxane layer comprises bridged silsesquioxane monomers and pendant silsesquioxane monomers. The present application designs and prepares the polysilsesquioxane gas separation membrane by the strategy of copolymerization of bridged silsesquioxane precursors and pendant silsesquioxane precursors, and constructs a composite membrane structure with a 'rigid skeleton / soft micropore', and realizes efficient molecular sieving of He / N2 through fine regulation of the polysilsesquioxane network pore size and pore environment, which is very obvious in the effect of helium extraction from liquefied natural gas tail gas, solves the problems of high cost and high energy consumption of traditional methods, and the problem of poor hydrothermal stability of traditional silica membranes which is not conducive to industrial production.

The invention discloses a filter DBR (Distributed Bragg Reflector) film layer etching process method, which comprises the following steps of: depositing silicon dioxide on a substrate of a DBR film layer deposition pre-process to form a silicon dioxide film layer; depositing aluminum on the silicon dioxide film layer to form an aluminum film layer; corroding the part, where the DBR film layer is reserved, of the aluminum film layer through photoetching and wet aluminum corrosion, so as to expose the silicon dioxide film layer at the corresponding part of the corroded and cleaned aluminum film layer; photoresist removal: removing the photoresist on the surface of the remaining aluminum film layer; a DBR film layer is deposited on the surface of the remaining aluminum film layer and the surface of the exposed silicon dioxide film layer after the photoresist is removed; etching the DBR film layer at a part corresponding to the remaining aluminum film layer through photoetching and dry etching, so that the aluminum film layer below the DBR film layer is exposed; the exposed aluminum film layer is completely removed through wet aluminum corrosion; and photoresist removal: removing the photoresist on the DBR film layer.

The invention relates to the technical field of semiconductor wafer processing, and discloses a vacuum chuck and a bonding connection method thereof. The vacuum chuck comprises two discs, a plurality of protruding parts are formed on one side of each disc, a groove used for constructing a flow channel is formed between every two adjacent protruding parts, and the side faces, away from the discs, of the protruding parts are sealing faces; a silicon dioxide film is arranged on each sealing surface; the silicon dioxide films of the two discs are in one-to-one correspondence and are in bonding connection; and the disc is made of silicon carbide or a silicon carbide composite material. The problems that silicon particles are randomly deposited on the inner wall of the flow channel due to a reaction welding sealing process in the prior art, and the roughness and uniformity of the inner surface of the flow channel are affected are solved; the defects that in the brazing sealing process, low-melting-point welding flux flows irregularly at high temperature, so that the uniformity of a welding layer is poor, and the welding flux overflows to block a flow channel are overcome, the cleanliness and the size precision of the internal flow channel are ensured, and the sealing performance of the vacuum chuck is improved.

An ultra-high charge density electret is disclosed. The ultra-high charge density electret includes a three-dimensional structure with multiple sidewalls. A porous silica film is formed on the multiple sidewalls, and the porous silica film is charged by multiple positive or negative ions.

The invention provides a trench filling method based on an FCVD process, and the method comprises the steps: carrying out the initial oxygen insertion treatment and solidification treatment of a formed flowing film layer, forming a solidified nitrogen-rich silicon oxide film layer, carrying out the further oxygen plasma treatment of the solidified nitrogen-rich silicon oxide film layer, enabling the contents of N and H elements in the whole film layer to be sharply reduced, and achieving the effect of improving the film quality; in addition, the oxygen plasma can also have a tamping effect on the film layer, so that the film layer is more compact; and finally, more nitrogen and hydrogen elements in the film layer can be removed through a steam oxygen insertion treatment process after steam annealing, the stable and high-purity silicon dioxide film is obtained through a hydroxyl dehydration condensation mode in subsequent dry annealing, and the content of the N element in the film layer is reduced, so that the purity of silicon dioxide is improved, and the silicon dioxide is closer to the K value of a silicon dioxide material.

The utility model discloses an anti-dazzle LED automobile lighting module, which relates to the technical field of LED automobile lamps, and comprises a main shell, a lampshade main body and an anti-dazzle component, the LED lamp main body is arranged outside the main shell, the lampshade main body is arranged outside the LED lamp main body, the anti-dazzle component is arranged inside the lampshade main body, and the anti-dazzle component is arranged inside the lampshade main body. The anti-dazzle assembly comprises a silicon dioxide film layer, a zirconium dioxide film layer, an anti-ultraviolet layer, an anti-fog layer, a polaroid and a light guide sheet, the zirconium dioxide film layer is arranged outside the silicon dioxide film layer, the anti-ultraviolet layer is arranged outside the zirconium dioxide film layer, the anti-fog layer is arranged outside the anti-ultraviolet layer, the polaroid is arranged outside the anti-fog layer, and the light guide sheet is arranged outside the light guide sheet. And a light guide sheet is additionally arranged in the lampshade main body. According to the anti-glare LED automobile lighting module, the situation that an existing automobile lighting lamp easily enters the sight line of an opposite driver, and consequently the opposite driver generates glare can be avoided, and the overall practicability and the use efficiency of the LED automobile lighting module are improved.

The invention relates to a silicon wafer edge etching device and a silicon wafer edge etching method.The silicon wafer edge etching device comprises a process chamber used for etching the edge of a silicon wafer, the process chamber comprises a first cavity and a second cavity which are arranged opposite to a box, and an isolation retaining wall is arranged between the first cavity and the second cavity; the process chamber is divided into a non-etching chamber and an etching chamber located at the periphery of the non-etching chamber; the isolation retaining wall is of an annular structure, the isolation retaining wall comprises a first area, and the isolation retaining wall is configured to be that when the edge of the silicon wafer is etched, the first area can cover a part of the chamfering area of the silicon wafer. Due to the arrangement of the isolation retaining wall, the silicon dioxide film on the edge of the part, close to the center of the silicon wafer, in the chamfering area of the silicon wafer is not etched, namely, the part, located on the side, close to the center of the silicon wafer, of the silicon wafer is completely covered with the silicon dioxide film, and the stress uniformity of the back face of the silicon wafer is guaranteed; the problem that the chamfering area of the silicon wafer is easy to break is solved.