Method and system for reducing by-products after SOG membranous etching

Abstract

The invention provides a method and system for reducing by-products after SOG film etching, and the method comprises the steps: carrying out the planarization processing under a preset first etching condition based on a manufactured high-step pattern sheet, and obtaining a planarized pattern sheet; performing mask-free etching on the planarized pattern sheet to obtain a mask-free pattern sheet; sequentially carrying out photoresist coating, exposure and development on the maskless pattern sheet to obtain a required pattern, and forming the required pattern on the surface of a wafer to obtain an initial etching product; and cleaning the initial etching product to obtain a final etching product. According to the method, the quality and the reliability of a final etching product are remarkably improved, by-products after SOG membranous etching are reduced, the efficiency and the product yield of the whole semiconductor manufacturing process are improved, and the by-products after SOG membranous etching are reduced by completely etching the SOG before the pattern sheet is formed.

Description

Technical Field

[0001] The invention belongs to the technical field of etching treatment, and in particular to a method and a system for reducing byproducts after SOG film etching. Background Art

[0002] In the semiconductor manufacturing process, dry etching technology plays an important role. However, dry etching technology also has some problems in the etching process. For example, when there is a large step height difference on the surface of the silicon wafer, dry etching often cannot ensure the uniformity of etching, which in turn has an adverse effect on the subsequent process steps and the performance of the final device. In order to solve this problem, silicon wafer flattening technology came into being and became an indispensable part of the semiconductor manufacturing process. Reverse etching flattening is an important method in silicon wafer flattening technology. Its basic principle is to evenly spin-coat a layer of dielectric material on the uneven surface of the silicon wafer. This layer of dielectric material is called a flattening sacrificial layer. The main function of the sacrificial layer is to fill the voids and depressions on the surface of the silicon wafer, so that the entire silicon wafer surface tends to be flat. Subsequently, the silicon wafer with the dielectric material spin-coated is etched by dry etching technology. Since there is a difference in the thickness of the high and low parts of the silicon wafer surface after the dielectric material is spin-coated, the etching rate of the high part is faster, while the etching rate of the low part is slower during the dry etching process. This difference in etching rate helps to further flatten the silicon wafer surface and achieve the goal of planarization.

[0003] In the process of reverse etching and planarization, it is very important to choose a suitable planarization spin-coating material. At present, the commonly used organic SOG is silicon-oxygen-carbon glass, which is based on a siloxane structure and contains a large amount of carbon ions. This organic material can form a uniform and dense film after spin coating, effectively filling the unevenness of the silicon wafer surface. However, organic SOG will produce a large amount of polymers during the dry etching process. These polymers are not only difficult to remove, but also affect the adhesion of the photoresist and increase the difficulty of cleaning. Summary of the invention

[0004] In order to solve the problem that a large amount of polymers are generated during organic SOG dry etching, which affects the adhesion of photoresist and increases the difficulty of cleaning, the present invention provides a method and system for reducing byproducts after SOG film etching.

[0005] To achieve the above object, the present invention provides the following technical solutions: The present invention proposes a method for reducing byproducts after SOG film etching, comprising the following steps: Performing a planarization process on the manufactured high-step graphic sheet under a preset first etching condition to obtain a planarized graphic sheet; Performing maskless etching on the planarized pattern sheet to obtain a maskless pattern sheet; The maskless pattern sheet is sequentially subjected to photoresist coating, exposure and development to obtain a desired pattern, and the desired pattern is formed on the surface of the wafer to obtain an initial etching product; The initial etching product is cleaned to obtain a final etching product.

[0006] Preferably, the production of the high-step graphic sheet includes: Obtaining a graphic sheet, and cleaning the surface of the graphic sheet; Performing surface oxidation treatment on the cleaned pattern sheet to obtain a high-step pattern; Under the first etching condition, the high-step pattern is deposited on the pattern sheet by a spin coating liquid using a chemical vapor deposition method with a low deposition temperature, so as to form a thin film on the surface of the high-step pattern sheet to obtain a planarized pattern sheet.

[0007] Preferably, the chemical vapor deposition method with low deposition temperature to deposit the spin coating liquid onto the pattern sheet comprises: The chamber temperature in the vapor deposition equipment is set to 350℃~450℃, the chamber pressure is 1.5Torr~2.5Torr, the RF power is 800W~1200W, the silane flow rate into the vapor deposition equipment is 0.1slm~0.3slm, the nitrous oxide flow rate is 2.5slm~3.5slm, and the nitrogen flow rate is 4slm~5slm. Nitrogen is used as a carrier gas to bring silane into the chamber, and nitrous oxide is ionized under RF operation to react on the surface of the silicon wafer to form solid silicon dioxide.

[0008] Preferably, the first etching conditions are: pressure 1200~1700mT, power 500~700W, flow rate of trifluoromethane 50~70sccm, flow rate of carbon tetrafluoride 140~180sccm, flow rate of argon 230~280sccm, and flow rate of oxygen 5~15sccm.

[0009] Preferably, performing maskless etching on the planarized pattern sheet to obtain the maskless pattern sheet comprises: The planarized pattern sheet is etched at an etching temperature and in a chamber with a pressure of 1500 mT by introducing carbon tetrafluoride and trifluoromethane to a depth of 1.4 μm, and is taken out after etching for 2 minutes to obtain an etched pattern sheet; The etching pattern sheet is cleaned and dried in sequence to obtain a mask-free pattern.

[0010] Preferably, sequentially coating the maskless pattern sheet with photoresist, exposing and developing the maskless pattern sheet comprises: Uniformly coating a layer of photoresist with a thickness of 1 to 2 μm on the surface of the planarized pattern sheet to obtain a first pattern sheet; Exposing the first graphic sheet to an exposure energy of 140ms to 180ms, and then taking it out to obtain a second graphic sheet; The second pattern sheet is placed in a developer, the temperature of the developer is controlled to be 20° C. to 25° C., and immersed for 1 min to 3 min to obtain a desired pattern.

[0011] Preferably, the cleaning of the initial etching product comprises: The initial etched product is placed in a plasma processing device, and oxygen with a flow rate of 500sccm~700sccm is introduced. The oxygen molecules are excited to form plasma through a high-frequency electric field with a power of 600W~800W, so that the active oxygen atoms in the plasma react with the polymer residues on the initial etched product for 30min~50min to be converted into a volatile gas, thereby obtaining a final etched product.

[0012] Preferably, the cleaning of the initial etching product comprises: The initial etching product is placed in a cleaning agent so that the cleaning agent can fully cover the surface of the silicon wafer. After stirring for 30 minutes, it is taken out and rinsed with deionized water for 3 to 5 times. Finally, after drying, the final etching product is obtained.

[0013] Preferably, the cleaning agent comprises an organic solvent, an acidic solution or an alkaline solution; Wherein, the organic solvent is one or two of acetone and ethanol; The acidic solution is one or both of dilute sulfuric acid and dilute hydrochloric acid; The alkaline solution is one or both of sodium hydroxide and potassium hydroxide.

[0014] The present invention proposes a system for reducing byproducts after SOG film etching, based on the above-mentioned method for reducing byproducts after SOG film etching, comprising: The first processing unit is configured as follows: Used to perform a flattening process on the manufactured high-step graphic sheet under a preset first etching condition to obtain a flattened graphic sheet; The second processing unit is configured as follows: Used to perform maskless etching on the planarized pattern sheet to obtain a maskless pattern sheet; The third processing unit is configured as follows: It is used to sequentially coat the maskless pattern sheet with photoresist, expose and develop it to obtain a desired pattern, and to shape the desired pattern on the surface of the wafer to obtain an initial etching product; The fourth processing unit is configured to: Used to clean the initial etching product to obtain the final etching product.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention proposes a method for reducing by-products after SOG film etching. The method ensures the accuracy of subsequent steps through flattening of high-step graphic sheets, reduces etching errors caused by surface unevenness, simplifies the process through maskless etching steps, and maintains the integrity of the graphics. The coating, exposure and development processes of photoresist accurately define the required graphics and accurately shape them on the surface of a wafer, thereby improving the resolution and accuracy of the graphics. By-products such as residues or contaminants generated during the etching process are effectively removed through meticulous cleaning, thereby significantly improving the quality and reliability of the final etched product. Not only are by-products after SOG film etching reduced, but also the efficiency and product yield of the entire semiconductor manufacturing process are improved. Moreover, all SOG is etched before forming the graphic sheet to achieve the reduction of by-products after SOG film etching.

[0016] Furthermore, the method effectively removes dust, grease and other impurities by cleaning the surface of the graphic sheet, and not only enhances the adhesion of the graphic sheet surface through surface oxidation treatment, but also forms a clear high-step graphic. The spin-coating liquid is deposited onto the graphic sheet using a chemical vapor deposition method with a low deposition temperature, which not only ensures the uniformity and density of the film, but also effectively reduces the thermal stress caused by high temperature, thereby reducing defects that may occur during the etching process. The flattened graphic sheet formed lays a solid foundation for subsequent maskless etching and photolithography steps, improves the efficiency of the entire process and product yield, further reduces the by-products after SOG film etching, and improves the performance and reliability of semiconductor devices.

[0017] Furthermore, the method adopts a chemical vapor deposition method with a low deposition temperature. Under a chamber temperature of 350° C. to 450° C., a chamber pressure of 1.5 Torr to 2.5 Torr, and a radio frequency power of 800 W to 1200 W, the silane flow rate is 0.1 slm to 0.3 slm, the nitrous oxide flow rate is 2.5 slm to 3.5 slm, and the nitrogen flow rate is 4 slm to 5 slm, thereby achieving efficient deposition of the spin-coating liquid on the graphic wafer. Nitrogen is used as a carrier gas to effectively bring silane into the chamber, where it is ionized with nitrous oxide under the action of radio frequency, and finally reacts on the surface of the silicon wafer to generate a solid silicon dioxide film, thereby lowering the temperature and reducing the influence of thermal stress on the graphic wafer. Moreover, by precisely controlling the flow rate of the reaction gas, the uniformity and quality of the film are ensured, providing a high-quality substrate for subsequent etching steps, further reducing the byproducts after SOG film etching, and improving the overall performance and reliability of semiconductor devices.

[0018] Furthermore, this method achieves precise etching of the surface of the graphic sheet by setting appropriate etching temperature and pressure conditions (1500mT) and selecting carbon tetrafluoride and trifluoromethane as etching gases. The etching depth reaches 1.4μm, and the entire process takes only 2 minutes, which significantly improves production efficiency. After etching is completed, the residues and contaminants generated during the etching process are effectively removed through careful cleaning and drying treatment, ensuring the cleanliness and quality of the maskless graphic sheet. It not only simplifies the complex process of traditional mask etching and reduces production costs, but also ensures the accuracy and consistency of the etched pattern by precisely controlling the etching parameters.

[0019] Furthermore, the method obtains a first graphic sheet by uniformly coating a layer of photoresist on the surface of a planarized graphic sheet, irradiating the first graphic sheet at an exposure energy of 140ms to 180ms so that the photoresist undergoes a photochemical reaction in a designated area, providing a clear pattern for a subsequent development step, placing the second graphic sheet in a developer controlled at a temperature of 20°C to 25°C and soaking for 1 to 3 minutes, accurately removing the photoresist in the exposed area, obtaining a desired pattern, and improving the quality and accuracy of the photolithography pattern. Furthermore, by optimizing the temperature and soaking time of the developer, defects caused by improper development are reduced, providing a high-quality graphic template for a subsequent etching step, and further improving the overall performance and reliability of semiconductor devices.

[0020] Furthermore, the method adopts advanced plasma treatment technology, places the initial etching product into a plasma treatment device, and introduces oxygen at a flow rate of 500sccm~700sccm. Through the excitation of a high-frequency electric field of 600W~800W, the oxygen molecules are converted into plasma, and the active oxygen atoms contained in the plasma have extremely strong reactivity. These active oxygen atoms chemically react with the polymer residues on the initial etching product. After a treatment time of 30min~50min, the residues are converted into volatile gases, thereby achieving effective cleaning of the product and completely removing the by-products and residues generated during the etching process. By precisely controlling the plasma treatment parameters, the uniformity and thoroughness of the cleaning are ensured, and the quality and reliability of the final etching product are further improved, laying a solid foundation for the subsequent semiconductor manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic flow chart of a method for reducing byproducts after SOG film etching proposed by the present invention; Figure 2 A schematic diagram of a high-step pattern sheet in a method for reducing by-products after SOG film etching proposed by the present invention; Figure 3This is one of the schematic diagrams of planarizing a pattern sheet in a method for reducing byproducts after SOG film etching proposed by the present invention; Figure 4 The second schematic diagram of a planarized pattern sheet in a method for reducing byproducts after SOG film etching proposed by the present invention; Figure 5 A schematic diagram of a maskless pattern sheet in a method for reducing byproducts after SOG film etching proposed by the present invention; Figure 6 A schematic diagram of a second pattern sheet in a method for reducing byproducts after SOG film etching proposed by the present invention; Figure 7 A schematic diagram of an initial etching product in a method for reducing by-products after SOG film etching proposed by the present invention; Figure 8 A schematic diagram of maskless etching results in a method for reducing byproducts after SOG film etching proposed by the present invention; Fig. 9 One of the SEM electron microscope images of the embodiment proposed by the present invention; Fig.10 This is the second SEM electron microscope image of the embodiment proposed by the present invention; Fig.11 This is the third SEM electron microscope image of the embodiment proposed in the present invention. DETAILED DESCRIPTION

[0022] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0024] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0025] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] See also Figure 1 The present invention proposes a method for reducing by-products after SOG film etching. The method includes maskless etching, photolithography, hole etching, photoresist removal and cleaning, which can make the by-products after SOG film etching easier to remove, without residual by-products, and the side wall of the product has a smooth morphology, which significantly improves the apparent qualified rate of the product and improves the product performance.

[0029] The specific steps include: Performing a planarization process on the manufactured high-step graphic sheet under a preset first etching condition to obtain a planarized graphic sheet; Specifically, the production of high-step graphic sheets includes: Get a 6-inch bulk silicon graphic sheet, clean the surface of the graphic sheet, remove the debris on the surface of the graphic sheet, and then perform surface oxidation treatment on the cleaned graphic sheet, that is, perform oxidation treatment on the cleaned graphic sheet to remove organic matter, oxides and particles on the surface of the graphic sheet to ensure that there are no pollutants on the surface, such as Figure 2 As shown, a high-step graphic piece is obtained; The high-step graphic sheet is loaded onto a sample stage in a reaction chamber in a vapor deposition device, and PEOXIDE is deposited onto the graphic sheet by a chemical vapor deposition method with a low deposition temperature, including: setting the chamber temperature in the vapor deposition device to 350°C~450°C, the chamber pressure to 1.5Torr~2.5Torr, preferably 2Torr, the radio frequency power to 800W~1200W, preferably 1000W, the silane flow rate introduced into the vapor deposition device to 0.1slm~0.3slm, preferably 0.2slm, the nitrous oxide flow rate to 2.5slm~3.5slm, and the nitrogen flow rate to 4slm~5slm, preferably 4.5slm, and using nitrogen as a carrier gas to bring silane into the chamber and nitrous oxide (N2O), ionized under radio frequency operation, and reacted on the surface of the silicon wafer to generate solid silicon dioxide.

[0030] The first etching condition is preset, and the spin coating liquid is deposited on the pattern piece by using a chemical vapor deposition method with a low deposition temperature to form a thin film on the surface of the high-step pattern piece, such as Figure 3 and Figure 4 As shown, a planarized pattern sheet is obtained; wherein the spin coating liquid is spin-coated silicon glass (SOG); the first etching condition is: the chamber pressure in the vapor deposition equipment is 1200mT~1700mT, the etching menu power in the vapor deposition equipment is 500W~700W, the flow rate of trifluoromethane CHF3 is 50sccm~70sccm, the flow rate of carbon tetrafluoride CF4 is 140sccm~180sccm, the flow rate of Ar is 230sccm~280sccm, and the flow rate of O2 is 5sccm~15sccm. Preferably, the chamber pressure in the vapor deposition equipment is 1500mT, the etching menu power in the vapor deposition equipment is 600W, the flow rate of trifluoromethane CHF3 is 60sccm, the flow rate of carbon tetrafluoride CF4 is 160sccm, the flow rate of Ar is 250sccm, and the flow rate of O2 is 10sccm.

[0031] Performing maskless etching on the planarized pattern sheet to obtain a maskless pattern sheet; Specifically, the planarized pattern sheet is placed in a maskless etching device, the etching depth is set to 1.4 μm, the etching temperature is set to 5° C., CF4 with a flow rate of 160 sccm and CHF3 with a flow rate of 60 sccm are introduced into the chamber with a pressure of 1500 mT to etch the planarized pattern sheet, and the etching pattern sheet is taken out after etching for 2 minutes to obtain an etched pattern sheet, and then the etched pattern sheet is sequentially cleaned and dried to remove the residues and contaminants generated during the etching process, such as Figure 5 As shown, a maskless graphic sheet is obtained.

[0032] The maskless pattern sheet is sequentially subjected to photoresist coating, exposure and development to obtain the desired pattern, and the desired pattern is formed on the wafer surface to obtain the initial etching product; Specifically, a maskless pattern sheet is placed on a coating table, and a layer of photoresist with a thickness of 1 to 2 μm, preferably 2 μm, is uniformly coated on the surface of the maskless pattern sheet using a coating device; wherein the photoresist is coated by spin coating, and the photoresist is uniformly distributed on the surface of the silicon wafer using centrifugal force to obtain a first pattern sheet; The first pattern sheet is placed in a photolithography machine, and the irradiation area of ​​the light of the photolithography machine is adjusted to cover the outer surface of the first pattern sheet for exposure. The first pattern sheet is taken out after exposure for 140ms to 180ms, preferably 160ms. Figure 6 As shown, a second graphic piece is obtained; The second pattern sheet is placed in a developer, the temperature of the developer is controlled to 20°C to 25°C, preferably 22°C, and soaked for 1min to 3min to remove the photoresist in the exposed area, thereby forming a desired pattern on the surface of the second pattern sheet, and then forming the desired pattern on the surface of the wafer, such as Figure 7 As shown, the initial etching product is obtained. During the immersion process, the developer is replenished so that the concentration of the developer is always maintained at 2.38%.

[0033] The initial etching product is cleaned of residues to obtain a final etching product.

[0034] In this embodiment, the initial etched product is placed in a plasma treatment device, oxygen is introduced into the plasma treatment device at a flow rate of 500 sccm to 700 sccm, preferably 600 sccm, and the oxygen molecules are excited to form plasma by a high-frequency electric field with a power of 600 W to 800 W, preferably 700 W, so that the active oxygen atoms in the plasma react with the polymer residues on the initial etched product for 30 min to 50 min, preferably 45 r / min, to convert all the polymer residues on the initial etched product into volatile gases, and these gases are extracted by a vacuum pump, thereby removing the polymer residues on the surface of the silicon wafer, such as Figure 8 As shown, the final etching product is obtained.

[0035] In this embodiment, the following steps can also be used to clean the polymer residues on the initial etching: The cleaning agent used in this article is an organic solvent cleaning agent + IPA solution, wherein the organic solvent cleaning agent is named EKC.

[0036] A cleaning agent is configured, and the cleaning agent includes an organic solvent, an acidic solution or an alkaline solution; wherein the organic solvent is one or both of acetone and ethanol; the acidic solution is one or both of dilute sulfuric acid and dilute hydrochloric acid; and the alkaline solution is one or both of sodium hydroxide and potassium hydroxide.

[0037] Place the cleaning agent in the cleaning tank, and put the initial etching product into the cleaning tank so that the cleaning agent can fully cover the surface of the silicon wafer. After circulating in the cleaning tank and soaking for 30 minutes, take it out and soak it in IPA solvent for 10 minutes. Take out the initial etching product, rinse it with deionized water for 3 to 5 times, and finally dry it to obtain the final etching product.

[0038] In this embodiment, the drying process is to place the initial etched product after rinsing with deionized water into a drying device, the drying chamber rotates at 400r / min~2000r / min, preferably 1000r / min, and blow 65℃~85℃ hot nitrogen into the drying chamber, preferably 75r / min, to accelerate the removal of deionized water, and the deionized water remaining on the initial etched product is thrown out by a centrifugal device to complete the drying of the initial etched product to obtain the final etched product.

[0039] The method is further explained below with reference to the embodiments: Figure 9~Figure 10 In order to optimize the silicon wafer before the process, a large amount of by-products remain at the bottom and side walls of the pattern, which cannot be completely removed by degumming and cleaning. Fig.11 The figure shown in the figure is obtained after using this method. Fig.11 It can be observed that the by-products are completely removed, which reflects that the method completely solves the problem of the difficulty in removing SOG film etching by-products.

[0040] The present invention also proposes a system for reducing byproducts after SOG film etching, which is used to implement the above method, including a planarization processing unit, an etching processing unit, a photolithography processing unit and a cleaning processing unit; The planarization processing unit is configured to: perform planarization processing on the manufactured high-step graphic sheet under a preset first etching condition to obtain a planarized graphic sheet; The method is further configured to: obtain a graphic sheet, clean the surface of the graphic sheet, remove impurities on the surface of the graphic sheet, and then perform surface oxidation treatment on the cleaned graphic sheet, that is, perform oxidation treatment on the cleaned graphic sheet using xx to remove organic matter, oxides and particles on the surface of the graphic sheet, ensure that there are no pollutants on the surface, and obtain a high-step graphic sheet; load the high-step graphic sheet onto a sample stage in a reaction chamber in a vapor deposition device, preset a first etching condition, and use a chemical vapor deposition method with a low deposition temperature to deposit a spin coating liquid on the graphic sheet, so as to form a thin film on the surface of the high-step graphic sheet, and obtain a flattened graphic sheet; An etching processing unit is configured to: perform maskless etching on the planarized pattern sheet to obtain a maskless pattern sheet; The method is further configured as follows: placing the planarized graphic sheet into a maskless etching device, setting the etching depth to 1.4 μm and the etching temperature to 5°C, introducing CF4 and CHF3 at a flow rate of 160 sccm and 60 sccm respectively into a chamber at a pressure of 1500 mT to etch the planarized graphic sheet, taking it out after etching for 2 minutes to obtain an etched graphic sheet, and then successively cleaning and drying the etched graphic sheet to remove residues and contaminants generated during the etching process, and then successively cleaning and drying the etched graphic sheet to remove residues and contaminants generated during the etching process to obtain a maskless graphic sheet.

[0041] The photolithography processing unit is configured to: sequentially perform photoresist coating, exposure and development on the maskless pattern sheet to obtain a desired pattern, and form the desired pattern on the wafer surface to obtain an initial etching product; It is further configured as follows: placing a maskless graphic sheet on a coating table and using a coating device to uniformly coat a layer of photoresist with a thickness of 2 μm on the surface of the maskless graphic sheet; wherein, the photoresist coating process is carried out by spin coating, and the photoresist is evenly distributed on the surface of the silicon wafer by centrifugal force to obtain a first graphic sheet; placing the first graphic sheet in a photolithography machine, adjusting the irradiation area of ​​the light of the photolithography machine to cover the outer surface of the first graphic sheet for exposure, and taking it out after exposure for 160ms to obtain a second graphic sheet; placing the second graphic sheet in a developer, controlling the temperature of the developer to 22°C, soaking for 3 minutes, removing the photoresist in the exposure area, thereby forming a desired pattern on the surface of the second graphic sheet, and then molding the desired pattern on the surface of the wafer to obtain an initial etching product. wherein, during the soaking process, the developer is replenished so that the concentration of the developer is always maintained at 2.38%.

[0042] The cleaning processing unit is configured to clean the initial etching product to obtain a final etching product.

[0043] It is further configured as follows: oxygen is introduced into the plasma processing equipment at a flow rate of 600 sccm, oxygen molecules are excited to form plasma through a high-frequency electric field with a power of 700 W, active oxygen atoms in the plasma react with polymer residues on the initial etching product for 40 minutes, all polymer residues on the initial etching product are converted into volatile gases, and these gases are extracted by a vacuum pump, thereby removing the polymer residues on the surface of the silicon wafer to obtain the final etching product.

[0044] Or it is configured as follows: prepare a cleaning agent, put an organic solvent cleaning agent in a cleaning tank, and put the initial etching product into the cleaning tank so that the cleaning agent can fully cover the surface of the silicon wafer, circulate in the cleaning tank and soak for 30 minutes, then take it out and soak it in IPA solvent for 10 minutes, take out the initial etching product, rinse it with deionized water 4 times, and finally dry it to obtain the final etching product.

[0045] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0046] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for reducing byproducts after SOG film etching, characterized in that: The following steps are involved: Performing a planarization process on the manufactured high-step graphic sheet under a preset first etching condition to obtain a planarized graphic sheet; Performing maskless etching on the planarized pattern sheet to obtain a maskless pattern sheet; The maskless pattern sheet is sequentially subjected to photoresist coating, exposure and development to obtain a desired pattern, and the desired pattern is formed on the surface of the wafer to obtain an initial etching product; The initial etching product is cleaned to obtain a final etching product.

2. The method for reducing byproducts after SOG film etching according to claim 1, characterized in that: The production of the high-step graphic sheet includes: Obtaining a graphic sheet, and cleaning the surface of the graphic sheet; Performing surface oxidation treatment on the cleaned pattern sheet to obtain a high-step pattern; Under the first etching condition, the high-step pattern is deposited on the pattern sheet by a spin coating liquid using a chemical vapor deposition method with a low deposition temperature, so as to form a thin film on the surface of the high-step pattern sheet to obtain a planarized pattern sheet.

3. The method for reducing byproducts after SOG film etching according to claim 2, characterized in that: The chemical vapor deposition method with low deposition temperature deposits the spin coating liquid onto the pattern sheet, comprising: The chamber temperature in the vapor deposition equipment is set to 350℃~450℃, the chamber pressure is 1.5Torr~2.5Torr, the RF power is 800W~1200W, the silane flow rate into the vapor deposition equipment is 0.1slm~0.3slm, the nitrous oxide flow rate is 2.5slm~3.5slm, and the nitrogen flow rate is 4slm~5slm. Nitrogen is used as a carrier gas to bring silane into the chamber, and nitrous oxide is ionized under RF operation to react on the surface of the silicon wafer to form solid silicon dioxide.

4. The method for reducing byproducts after SOG film etching according to claim 3, characterized in that: The first etching conditions are: pressure 1200~1700mT, power 500~700W, flow rate of trifluoromethane 50~70sccm, flow rate of carbon tetrafluoride 140~180sccm, flow rate of argon 230~280sccm, and flow rate of oxygen 5~15sccm.

5. The method for reducing byproducts after SOG film etching according to claim 1, characterized in that: The planarized pattern sheet is subjected to maskless etching to obtain the maskless pattern sheet, comprising: The planarized pattern sheet is etched at an etching temperature and in a chamber with a pressure of 1500 mT by introducing carbon tetrafluoride and trifluoromethane to a depth of 1.4 μm, and is taken out after etching for 2 minutes to obtain an etched pattern sheet; The etching pattern sheet is cleaned and dried in sequence to obtain a mask-free pattern.

6. The method for reducing byproducts after SOG film etching according to claim 1, characterized in that: The process of sequentially coating the maskless pattern sheet with photoresist, exposing and developing the maskless pattern sheet comprises: Uniformly coating a layer of photoresist with a thickness of 1 to 2 μm on the surface of the planarized pattern sheet to obtain a first pattern sheet; Exposing the first graphic sheet to an exposure energy of 140ms to 180ms, and then taking it out to obtain a second graphic sheet; The second pattern sheet is placed in a developer, the temperature of the developer is controlled to be 20° C. to 25° C., and immersed for 1 min to 3 min to obtain a desired pattern.

7. The method for reducing byproducts after SOG film etching according to claim 1, characterized in that: The initial etching product is cleaned including: The initial etched product is placed in a plasma processing device, and oxygen with a flow rate of 500sccm~700sccm is introduced. The oxygen molecules are excited to form plasma through a high-frequency electric field with a power of 600W~800W, so that the active oxygen atoms in the plasma react with the polymer residues on the initial etched product for 30min~50min to be converted into a volatile gas, thereby obtaining a final etched product.

8. The method for reducing byproducts after SOG film etching according to claim 1, characterized in that: The initial etching product is cleaned including: The initial etching product is placed in a cleaning agent so that the cleaning agent can fully cover the surface of the silicon wafer. After stirring for 30 minutes, it is taken out and rinsed with deionized water for 3 to 5 times. Finally, after drying, the final etching product is obtained.

9. The method for reducing byproducts after SOG film etching according to claim 8, characterized in that: The cleaning agent includes an organic solvent, an acidic solution or an alkaline solution; Wherein, the organic solvent is one or two of acetone and ethanol; The acidic solution is one or both of dilute sulfuric acid and dilute hydrochloric acid; The alkaline solution is one or both of sodium hydroxide and potassium hydroxide.

10. A system for reducing byproducts after SOG film etching, based on the method for reducing byproducts after SOG film etching according to any one of claims 1 to 9, characterized in that: include: The first processing unit is configured as follows: Used to perform a flattening process on the manufactured high-step graphic sheet under a preset first etching condition to obtain a flattened graphic sheet; The second processing unit is configured as follows: Used to perform maskless etching on the planarized pattern sheet to obtain a maskless pattern sheet; The third processing unit is configured as follows: It is used to sequentially perform photoresist coating, exposure and development on the maskless pattern sheet to obtain a desired pattern, and to shape the desired pattern on the surface of the wafer to obtain an initial etching product; The fourth processing unit is configured to: Used to clean the initial etching product to obtain the final etching product.

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