Method for removing polyimide layer

Abstract

The invention relates to a method for removing a polyimide layer. The method comprises the following steps: etching the polyimide layer on the surface of a wafer; carrying out first cleaning on the etched wafer, and removing a by-product formed by etching the polyimide layer on the surface of the wafer; and performing second cleaning on the wafer after the first cleaning, and continuing to remove the by-products. According to the method for removing the polyimide layer, in the process of removing the polyimide layer, by-products formed by etching the polyimide layer are removed through the first cleaning and the second cleaning respectively, the by-products formed by etching are prevented from being accumulated on the polyimide layer or the wafer, and the removal effect of the polyimide layer is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, and in particular to a polyimide layer removal method. BACKGROUND

[0002] Polyimide (PI) is a kind of polymer material with good dielectric properties, high mechanical strength and strong heat resistance, which is widely used in electrical, aerospace and automotive industries. In the field of semiconductors, PI is widely used as an important insulating material for stress buffer layer, dielectric insulating layer, surface passivation layer, and surface planarization layer and protective layer in wafer level packaging of integrated circuits. When polyimide is applied to semiconductor materials, it usually needs to be patterned, and in order to simplify the photoetch process, polyimide with photosensitivity, i.e. photosensitive polyimide, is usually used. Similar to conventional photoresist process, during the coating process or exposure and development process, machine alarm abnormal interruption, insufficient exposure, and poor final development pattern quality may occur. When the process abnormality does not meet the product quality requirements, the polyimide layer on the wafer surface needs to be removed.

[0003] In related technologies, the technical solution for removing the polyimide layer may cause carbonization of the polyimide, affecting the removal effect of the polyimide layer. SUMMARY

[0004] Therefore, it is necessary to provide a polyimide layer removal method capable of improving the removal effect of the polyimide layer to solve at least one of the above technical problems.

[0005] In a first aspect, the present application provides a polyimide layer removal method. The method comprises: etching a polyimide layer on a wafer surface; performing first cleaning on the etched wafer to remove by-products formed by etching the polyimide layer on the wafer surface; and performing second cleaning on the first cleaned wafer to continue removing the by-products. In one embodiment, after the step of performing oxidation acid cleaning on the oxidized and cleaned wafer, the method further comprises: performing pure water cleaning and drying on the oxidation acid cleaned wafer.

[0006] In one embodiment, the step of etching the polyimide layer on the wafer surface comprises: ashing etching the wafer by plasma.

[0007] In one embodiment, the step of performing first cleaning on the etched wafer comprises: the first cleaning is oxidation cleaning, and the wafer is cleaned by ozone deionized water for a first preset time.

[0008] In one of the embodiments, the second cleaning of the first cleaned wafer includes: the second cleaning is an oxidizing acid cleaning, and the wafer is cleaned by a mixed acid solution for a second preset time length; and the mixed acid solution at least includes sulfuric acid, hydrogen peroxide and hydrofluoric acid.

[0009] In one of the embodiments, the mixed acid solution further includes isopropyl alcohol.

[0010] In one of the embodiments, before the step of etching the polyimide layer on the wafer surface, the method further includes: obtaining a curing state of the polyimide layer on the wafer surface; and if the curing state is that the polyimide layer has been cured, etching the polyimide layer on the wafer surface.

[0011] In one of the embodiments, after the step of obtaining the curing state of the polyimide layer on the wafer surface, the method further includes: if the curing state is that the polyimide layer has not been cured, removing the polyimide layer on the wafer surface by a third cleaning.

[0012] In one of the embodiments, the step of removing the polyimide layer on the wafer surface by the third cleaning includes: the third cleaning is a polar similar compatible principle cleaning, and the wafer is cleaned by a polar solvent for a third preset time length; and the polar solvent on the wafer surface after the third cleaning is removed.

[0013] In one of the embodiments, the polar solvent is at least one of N-methyl pyrrolidone, dimethyl sulfoxide and N, N-dimethylacetamide.

[0014] In one of the embodiments, after the step of second cleaning of the first cleaned wafer, the method further includes: checking whether the polyimide layer remains on the wafer surface, if the polyimide layer remains, continuing to etch, first clean and second clean the wafer until the polyimide layer does not remain on the wafer surface; and if the polyimide layer does not remain, obtaining the wafer without the polyimide layer remaining.

[0015] The above polyimide layer removal method removes the by-products formed by etching the polyimide layer by first cleaning and second cleaning respectively in the process of removing the polyimide layer, prevents the by-products formed by etching from accumulating on the polyimide layer or the wafer, and improves the polyimide layer removal effect. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A comparison diagram of etching effects of continuous dry etching;

[0017] Figure 2 A flowchart of the polyimide layer removal method in one of the embodiments;

[0018] Figure 3 Flow chart of the removing method of the polyimide layer in another embodiment;

[0019] Figure 4 Flow chart of the removing method of the cured polyimide layer in an embodiment;

[0020] Figure 5 Flow chart of the removing method of the uncured polyimide layer in an embodiment;

[0021] Figure 6 Flow chart of the removing method of the uncured polyimide layer in another embodiment;

[0022] Figure 7 Flow chart of the removing method of the polyimide layer in yet another embodiment;

[0023] Figure 8 Module diagram of the removing device of the polyimide layer in an embodiment;

[0024] Figure 9 Internal structure diagram of the computer device in an embodiment. DETAILED DESCRIPTION

[0025] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0027] As described in the background, the related art discloses a technical solution for removing the polyimide layer using dry plasma ashing etching. In the ashing etching process, the plasma and the polyimide layer mainly react in the vacuum chamber. Since the molecular structure of the polyimide layer is composed of long-chain carbon, hydrogen, nitrogen, and oxygen, the highly reactive monatomic oxygen in the oxygen plasma is prone to polymerization reaction with the carbon, hydrogen, nitrogen, and oxygen polymers in the polyimide layer, thereby generating volatile reaction products, and ultimately achieving the purpose of removing the polyimide layer.

[0028] However, when the polyimide is used as the passivation layer, the thickness of the polyimide layer can reach 10 to 30 microns, and in this case, the dry plasma ashing etching needs to be performed for a long time, but during the long-time ashing etching, the polyimide can be carbonized and thus cannot be removed, and therefore, the polyimide material needs to be removed by using a plurality of dry plasma ashing etching, but the removal effect is weakened with the increase of the number of times of dry plasma ashing etching. As shown in FIG. 8, the thickness of the unetched polyimide is 17 microns, the thickness of the polyimide after one dry etching is 4 microns, but the thickness of the polyimide after three dry etchings is still 0.7 microns, and the polyimide still has residues after the plurality of dry etchings, which leads to poor removal effect of the polyimide. Figure 1

[0029] Therefore, the polyimide layer removal method provided in the present application can reduce the residues after the polyimide layer is removed and improve the removal effect of the polyimide layer.

[0030] The polyimide layer removal method provided in the present application can be applied to a full-automatic wafer manufacturing system, and a main controller in the full-automatic wafer manufacturing system can control a wafer manufacturing device to perform corresponding wafer manufacturing processes, so as to perform ashing etching, oxidation cleaning, oxidation acid washing, pure water cleaning, and drying processes on the wafer.

[0031] In one embodiment, as shown in FIG. 1, a polyimide layer removal method is provided, and the method is taken as an example to be applied to a main controller in a full-automatic wafer manufacturing system, and the method includes the following steps. Figure 2

[0032] Step S110: etching a polyimide layer on a wafer surface.

[0033] Specifically, after the main controller receives a control instruction that the polyimide layer on the wafer surface needs to be removed, the wafer is moved to an etching device, so as to etch the polyimide layer on the wafer surface by using the etching device. The polyimide layer can be solidified or not solidified, and the physical and / or chemical etching can be used when the polyimide layer is etched.

[0034] Step S120: performing first cleaning on the etched wafer.

[0035] Specifically, after the etching device etches the polyimide layer on the wafer surface, the main controller moves the wafer to a cleaning device, so as to perform first cleaning on the etched wafer, thereby removing the by-products formed by etching the polyimide layer on the wafer surface.

[0036] Step S130: performing second cleaning on the wafer after the first cleaning.

[0037] ​​Specifically, the cleaning apparatus performs first cleaning on the wafer, and then performs second cleaning on the wafer after the first cleaning to continue removing by-products. The first cleaning and the second cleaning can both be wet cleaning, and the solvents used in the wet cleaning can be the same or different.

[0038] The removal method of the polyimide layer removes by-products formed by etching the polyimide layer through first cleaning and second cleaning respectively during the removal of the polyimide layer, prevents the by-products formed by etching from accumulating on the polyimide layer or the wafer, and improves the removal effect of the polyimide layer.

[0039] In one embodiment, in step S110, the step of etching the polyimide layer on the surface of the wafer includes: ashing etching the wafer by plasma.

[0040] Specifically, in the embodiment, the polyimide layer on the surface of the wafer is etched by ashing etching the wafer by plasma. After the main controller receives a control instruction for removing the polyimide layer on the surface of the wafer, the wafer is moved to an ashing etching apparatus. When ashing etching is performed, the ashing etching apparatus can plasma the oxygen, and then make the highly reactive monatomic oxygen in the oxygen plasma react with the polyimide layer to generate volatile reactants, thereby completing the ashing etching of the wafer. It can be understood that, in the case that the thickness of the polyimide layer is relatively large, in order to prevent the reaction time of the ashing etching from being too long and causing the carbonization of the polyimide, the reaction time of the ashing etching can be shortened, and only part of the polyimide layer is ashing etched. The specific duration can be set according to the thickness of the current polyimide layer, the rate of ashing etching and other parameters, which is not limited herein.

[0041] In one embodiment, the step of ashing etching the wafer by plasma includes: ashing etching the wafer by plasma formed by carbon tetrafluoride and oxygen.

[0042] Specifically, in the embodiment, after the main controller moves the wafer to the ashing etching apparatus, the ashing etching apparatus is controlled to introduce carbon tetrafluoride (CF4) and oxygen (O2) into the vacuum cavity, and then high-frequency high-voltage is applied to generate plasma (active free radicals, ions and electrons with energy) through glow discharge, and chemically react with the polyimide layer to remove the polyimide. In the embodiment, the ashing etching by carbon tetrafluoride and oxygen can remove most of the polyimide polymer material, but there will be a lot of fluorocarbon by-product polymers remaining on the surface of the polyimide after ashing etching, and in the case that the thickness of the polyimide layer is relatively large, there will also be polyimide material that has not been etched at the bottom. Therefore, the by-products formed by ashing etching can be further removed through subsequent cleaning steps. In some other embodiments, ashing etching can also be performed by oxygen only.

[0043] In one embodiment, the first cleaning of the etched wafer in step S120 includes: the first cleaning is an oxidation cleaning.

[0044] Specifically, in the embodiment, after the etching equipment completes the etching of the polyimide layer on the wafer surface, the main controller moves the wafer to an oxidation cleaning tank in the wet tank equipment, so as to perform oxidation cleaning on the wafer through the oxidation cleaning tank. The oxidation cleaning is used to modify and remove the by-products formed after the etching of the polyimide layer. The oxidation cleaning is performed by using a strong oxidizing agent to clean the wafer. After the oxidation cleaning, the by-products formed after the etching are oxidized, the polymer molecular bonds are broken, and hydroxyl groups and other groups with high solubility and easy removal are formed. Through the oxidation cleaning, most of the by-products formed after the etching of the polyimide layer can be modified and removed.

[0045] In some embodiments, the wafer is cleaned by using ozone deionized water (DIO3) for a first preset time period during the oxidation cleaning. In some embodiments, the first preset time period is 3 to 5 minutes. The ozone deionized water can react with the by-product polymers on the wafer surface. Since the ozone deionized water is a strong oxidizing agent, after the cleaning, the by-products after the etching are oxidized, the by-product polymer molecular bonds are broken, and hydroxyl groups and other groups with high solubility and easy removal are formed. Through the oxidation cleaning by using the ozone deionized water, most of the by-products after the ashing etching can be modified and removed. In some other embodiments, the hydrogen peroxide (H2O2) can also be used for the oxidation cleaning.

[0046] In one embodiment, the second cleaning of the wafer after the first cleaning in step S130 includes: the second cleaning is an oxidation acid cleaning.

[0047] Specifically, in the embodiment, after the cleaning equipment performs the first cleaning on the wafer, the main controller can control the wet tank equipment to transfer the wafer to an oxidation acid cleaning tank. The oxidation acid cleaning is used to further remove the by-products formed after the etching of the polyimide layer. The oxidation acid cleaning is performed by using an oxidizing agent and an acidic solution to clean the wafer. Through the comprehensive action of the oxidizing agent and the acidic solution, the by-products formed after the etching of the polyimide layer can be further removed.

[0048] In one embodiment, the wafer is cleaned by using a mixed acid solution for a second preset time period during the oxidation acid cleaning. The mixed acid solution at least includes: sulfuric acid (H2SO4), hydrogen peroxide (H2O2), and hydrofluoric acid (HF). In some embodiments, the second preset time period is 1 to 3 minutes, and the reaction temperature is room temperature. The oxidation of the sulfuric acid and the hydrogen peroxide can decompose the oxidized organic by-products, and the principle equation is as follows:

[0049] H2SO4+H2O2→H2SO5+H2O

[0050] H2SO5+C X H Y O Z →H2SO4+XCO2+0.5YH2O

[0051] Hydrofluoric acid can slightly etch the wafer, thereby taking away the particles on the surface of the wafer, and the principle equation is as follows:

[0052] SiO2+4H + +6F - →SiF6 2- +2H2O

[0053] Through the comprehensive action of the mixed acid liquid, the by-products formed after the etching of the polyimide layer on the surface of the wafer can be further removed. In the case that the polyimide layer on the wafer needs to be etched again, after the oxidation acid washing, the by-products formed after the etching can be basically removed, so as to prevent the by-products formed after the etching from affecting the next etching.

[0054] In one embodiment, the mixed acid liquid further comprises isopropyl alcohol. Specifically, by adding isopropyl alcohol (IPA) in the mixed acid liquid, the hydrophilicity of the mixed acid liquid can be increased, so as to promote the chemical reaction and improve the efficiency of the mixed acid liquid in cleaning the wafer.

[0055] In one embodiment, as shown in FIG. 13, after the step of performing the second cleaning on the wafer cleaned in the first cleaning in step S130, the method for removing the polyimide layer further comprises: Figure 3

[0056] Step S140, performing pure water cleaning and drying on the wafer cleaned in the second cleaning.

[0057] Specifically, after the cleaning equipment completes the second cleaning of the wafer, the main controller controls the cleaning equipment to transfer the wafer to a pure water cleaning tank. The pure water cleaning tank can flush the surface of the wafer through spraying or overflow, so as to remove the by-products formed after the etching and the chemical liquid remaining on the surface of the wafer through physical means. Finally, the main controller controls the cleaning equipment to transfer the wafer to a drying tank to dry the surface of the wafer. It can be understood that when the thickness of the polyimide layer is relatively thick, the polyimide layer on the surface of the wafer can be completely removed by repeatedly performing steps S110 to S140, and the surface of the wafer after drying can be directly used to form a new polyimide layer.

[0058] ​In one specific embodiment, after ashing etching of the wafer, the wafer is first cleaned with ozone-deionized water, and then cleaned with a mixed acid solution including sulfuric acid, hydrogen peroxide, hydrofluoric acid, and isopropanol. This method can essentially remove all byproducts formed during the ashing etching of the polyimide layer. Related technologies generally use EKC pre-prepared cleaning solutions for wet cleaning, but EKC solutions are expensive. From an economic perspective, EKC solutions typically need to be recycled for 48 to 72 hours. However, when the polyimide layer is thick, a large amount of residual polymer remains. This residual polymer in the wet cleaning tank may contaminate other wafers being processed. To avoid the risk of contamination of wafers processed in the same tank, the polyimide layer can only be removed before changing the cleaning solution, which is detrimental to product flow and results in low wafer processing efficiency. This embodiment uses ozone-deionized water for oxidation cleaning. The production of ozone-deionized water requires only a small amount of oxygen, resulting in lower oxidation cleaning costs. Furthermore, any residual ozone-deionized water is easily eliminated by the plant's treatment facilities, causing no environmental impact. When using a mixed acid solution for oxidation pickling, sulfuric acid, hydrogen peroxide, hydrofluoric acid, and isopropanol can be directly mixed and used at the plant level. Compared to EKC finished solutions, this method is less expensive, and after cleaning the wafers, it does not require recycling, avoiding impact on other wafers and improving product flow efficiency.

[0059] The polyimide photosensitive material of this application is a negative adhesive. When the photoinitiator is exposed to ultraviolet light, it decomposes to generate active free radicals. These free radicals cause the polyimide precursor to crosslink and solidify. After being crosslinked by free radicals, the polyimide becomes insoluble, essentially insoluble in any organic solvent. By performing steps S110 to S130 of this application, the solidified polyimide layer on the wafer surface can be effectively removed. Similarly, the unsolidified polyimide layer can also be removed, but removing the unsolidified polyimide layer is simpler. Removing it through steps S110 to S130 results in lower removal efficiency and higher removal costs.

[0060] In one embodiment, such as Figure 4 As shown, in step S110, before the step of etching the polyimide layer on the wafer surface, the method for removing the polyimide layer further includes: obtaining the curing state of the polyimide layer on the wafer surface.

[0061] Specifically, the main controller can acquire the completed process steps of the wafer to determine whether the polyimide layer on the wafer surface has undergone exposure and curing, thus obtaining the curing state of the polyimide layer on the wafer surface. If the curing state is that the polyimide layer has been cured, then the polyimide layer on the wafer surface is etched. Specifically, if the main controller determines that the polyimide layer has been cured, it means that the polyimide layer on the wafer surface has undergone exposure and curing. At this time, the polyimide layer on the wafer surface needs to be etched, and the cleaning steps in S120 and S130 after etching are continued to remove the byproducts formed after the polyimide layer etching. In some other embodiments, when the thickness of the cured polyimide layer is relatively thick, the wafer needs to be etched. Therefore, after the second cleaning of the wafer, the wafer after the second cleaning also needs to be cleaned with pure water and dried to avoid the residual chemical liquid on the wafer from affecting the next etching. At this time, by repeatedly executing steps S110 to S140, the cured polyimide layer on the wafer surface can be completely removed.

[0062] In one embodiment, such as Figure 5 As shown, after obtaining the curing state of the polyimide layer on the wafer surface, the method for removing the polyimide layer further includes: if the curing state is that the polyimide layer is not cured, then the polyimide layer on the wafer surface is removed by a third cleaning.

[0063] Specifically, if the main controller determines that the polyimide layer is in an uncured state, it means that the polyimide layer on the wafer surface has not been exposed and cured. In this case, the main controller can transfer the wafer to a cleaning device for a third cleaning. It is understood that the third cleaning can be a wet cleaning process, and the solvent used in the third cleaning is different from that used in the first and second cleaning processes.

[0064] In one embodiment, such as Figure 6 As shown, the step of removing the polyimide layer on the wafer surface by the third cleaning includes: cleaning the wafer with a polar solvent for a third preset time.

[0065] Specifically, the third cleaning is a polarity-like compatibility principle cleaning, which cleans the polyimide layer on the wafer surface using this principle. This principle allows the polyimide layer on the wafer surface to dissolve in a polar solvent, thereby completely removing the uncured polyimide layer from the wafer surface. In some embodiments, the polar solvent can be at least one of N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), and N,N-dimethylacetamide (DMAc). In some embodiments, the preset duration of the third cleaning is 10 to 20 minutes.

[0066] In one embodiment, such as Figure 6 As shown, after cleaning the wafer with a polar solvent for a third preset time, the polar solvent on the surface of the wafer after the third cleaning is removed.

[0067] Specifically, in the third cleaning, the wafer is first cleaned by the polar solvent to dissolve the un-solidified polyimide on the wafer surface, and then the wafer is cleaned again to remove the polar solvent on the wafer surface. For example, the main controller first controls the wet tank device to clean the wafer by the N-methyl pyrrolidone solution based on the polar similar compatible principle, and then controls the wet tank device to transfer the wafer to the isopropyl alcohol solution tank, and clean the wafer by isopropyl alcohol to remove the N-methyl pyrrolidone solution on the wafer surface.

[0068] In one embodiment, after the step of removing the polyimide layer on the wafer surface by the third cleaning, the wafer after the third cleaning is subjected to pure water cleaning and drying.

[0069] Specifically, after the wet tank device completes the third cleaning of the wafer, the main controller controls the wet tank device to transfer the wafer to the pure water cleaning tank, which can flush the wafer surface by spraying or overflow to completely remove the residual solution on the wafer surface. Finally, the main controller controls the wet tank device to transfer the wafer to the drying tank to dry the wafer surface. Through the steps of third cleaning, pure water cleaning and drying in this embodiment, the un-solidified polyimide layer on the wafer surface can be completely removed, which facilitates the subsequent formation of a polyimide layer on the wafer surface.

[0070] In one embodiment, as shown in FIG. 1, Figure 7 After the step of second cleaning of the wafer after the first cleaning, the method for removing the polyimide layer further includes: checking whether the wafer surface is residual with the polyimide layer, if the wafer surface is residual with the polyimide layer, continuing to etch, first clean and second clean the wafer until the wafer surface is not residual with the polyimide layer.

[0071] Specifically, after the polyimide layer is removed by the steps S110 to S130 in this embodiment, the wafer surface needs to be checked by an optical microscope or a scanning electron microscope to ensure that the polyimide layer on the wafer surface is completely removed and no residual, if the wafer surface is residual with the polyimide layer, the steps S110 to S130 need to be repeatedly executed to continue to etch, first clean and second clean the wafer until the wafer surface after checking is not residual with the polyimide layer.

[0072] In one embodiment, as shown in FIG. 1, Figure 7 After the step of checking whether the wafer surface is residual with the polyimide layer, the method for removing the polyimide layer further includes: if the wafer surface is not residual with the polyimide layer, obtaining the wafer without residual polyimide layer. Specifically, in the case that the wafer surface is not residual with the polyimide layer is checked, it indicates that the polyimide layer has been completely removed, at this time, the wafer can be subjected to subsequent process steps.

[0073] It can be understood that in the process of wafer manufacturing, the polyimide can be used as an insulating layer, a dielectric layer, a protective layer, etc., which can be selected according to the specific process requirements of the semiconductor device. When forming a polyimide layer on the wafer surface, generally, the steps of coating, pre-baking, exposure, development and post-baking are needed. When the wafer is coated, an uncured polyimide layer will be formed on the wafer surface; when the wafer is exposed, a cured polyimide layer will be formed on the wafer surface. In order to ensure the process quality, the polyimide layer on the wafer surface can be detected for defects after coating, exposure and development, respectively. In the coating, exposure and development processes, machine alarm abnormal interruption, insufficient exposure dose leading to poor final development pattern quality, etc. may occur. At this time, the polyimide layer can be determined to be not in accordance with the requirements through defect detection, and therefore the polyimide layer needs to be removed by the above-mentioned polyimide layer removal method.

[0074] It should be understood that although each step in the flowchart involved in each embodiment as described above is displayed in sequence according to the indication of the arrow, these steps are not necessarily executed in sequence according to the indication of the arrow. Unless explicitly stated herein, there is no strict order limitation for the execution of these steps, and these steps can be executed in other orders. Moreover, at least part of the steps in the flowchart involved in each embodiment as described above can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least part of other steps or steps or stages in other steps.

[0075] Based on the same inventive concept, the embodiments of the present application also provide a polyimide layer removal device for implementing the above-mentioned polyimide layer removal method. The problem-solving implementation scheme provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more polyimide layer removal device embodiments provided below can refer to the limitations of the polyimide layer removal method in the above text, which will not be repeated here.

[0076] In one embodiment, as shown in Figure 8 A polyimide layer removal device is provided, comprising: an etching module 210, a first cleaning module 220 and a second cleaning module 230, wherein:

[0077] The etching module 210 is used to etch the polyimide layer on the wafer surface;

[0078] The first cleaning module 220 is used to clean the etched wafer for the first time to remove the by-products formed by etching the polyimide layer on the wafer surface;

[0079] The second cleaning module 230 is configured to clean the wafer after the first cleaning, and continue to remove by-products.

[0080] In an embodiment, the etching module 210 is further configured to perform a plasma ashing etching on the wafer.

[0081] In an embodiment, the first cleaning module 220 is further configured to clean the wafer by using ozone deionized water for a first preset time, and the first cleaning is an oxidation cleaning.

[0082] In an embodiment, the second cleaning module 230 is further configured to clean the wafer by using mixed acid solution for a second preset time, and the second cleaning is an oxidation acid cleaning. The mixed acid solution at least includes sulfuric acid, hydrogen peroxide and hydrofluoric acid.

[0083] In an embodiment, the mixed acid solution further includes isopropyl alcohol.

[0084] In an embodiment, the removing device of the polyimide layer further includes a solidification state determining module configured to obtain a solidification state of the polyimide layer on the wafer surface, and if the solidification state is that the polyimide layer has been solidified, etch the polyimide layer on the wafer surface.

[0085] In an embodiment, the solidification state determining module is further configured to, if the solidification state is that the polyimide layer has not been solidified, remove the polyimide layer on the wafer surface by a third cleaning.

[0086] In an embodiment, the removing device of the polyimide layer further includes a third cleaning module configured to clean the wafer by using a polar solvent for a third preset time, and the third cleaning is a polar similar compatible principle cleaning. In an embodiment, the third cleaning module is further configured to remove the polar solvent on the wafer surface after the third cleaning.

[0087] In an embodiment, the polar solvent is at least one of N-methyl pyrrolidone, dimethyl sulfoxide and N,N-dimethylacetamide.

[0088] In an embodiment, the removing device of the polyimide layer further includes a residual inspection module configured to inspect whether the polyimide layer is left on the wafer surface, if the polyimide layer is left, continue to etch, first clean and second clean the wafer until the polyimide layer is not left on the wafer surface, and if the polyimide layer is not left, obtain the wafer without the polyimide layer left.

[0089] In an embodiment, a computer device is provided, which can be a terminal, and an internal structure diagram of the computer device can be as shown in Figure 9The computer device shown in the figure includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capability. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals in a wired or wireless manner. The wireless manner can be realized through WIFI, mobile cellular network, NFC (near field communication) or other technologies. The computer program is executed by the processor to realize a polyimide layer removal method or a wafer manufacturing method. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or a key, trackball or touchpad arranged on the shell of the computer device, or an external keyboard, touchpad or mouse, etc.

[0090] Those skilled in the art can understand that, Figure 9 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0091] In one embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program, and the processor executing the computer program to realize the steps in each of the above method embodiments.

[0092] In one embodiment, a computer readable storage medium is provided, which stores a computer program, and the processor executes the computer program to realize the steps in each of the above method embodiments.

[0093] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without being limited thereto.

[0094] Any combination of the technical features of the above embodiments can be made. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0095] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for removing a polyimide layer, characterized by, The method comprises: etching a polyimide layer on a wafer surface; first cleaning the wafer after etching to remove by-products formed by etching the polyimide layer on the wafer surface; second cleaning the wafer after the first cleaning to continue removing the by-products.

2. The method of removing polyimide layers according to claim 1, wherein The step of etching the polyimide layer on the wafer surface comprises: ashing etching the wafer by plasma.

3. The method of removing polyimide layers according to claim 1, wherein The step of first cleaning the wafer after etching comprises: The first cleaning is an oxidation cleaning, and the wafer is cleaned by ozone deionized water for a first preset time.

4. The method of removing polyimide layers according to claim 1, wherein The step of second cleaning the wafer after the first cleaning comprises: The second cleaning is an oxidation acid cleaning, and the wafer is cleaned by a mixed acid solution for a second preset time; wherein the mixed acid solution at least comprises sulfuric acid, hydrogen peroxide and hydrofluoric acid.

5. The method of removing polyimide layers according to claim 4, wherein The mixed acid solution further comprises isopropyl alcohol.

6. The method for removing a polyimide layer according to any one of claims 1 to 5, characterized in that, Before the step of etching the polyimide layer on the wafer surface, the method further comprises: obtaining a curing state of the polyimide layer on the wafer surface; if the curing state is that the polyimide layer has been cured, etching the polyimide layer on the wafer surface.

7. The method of removing polyimide layers according to claim 6, wherein After the step of obtaining the curing state of the polyimide layer on the wafer surface, the method further comprises: if the curing state is that the polyimide layer has not been cured, removing the polyimide layer on the wafer surface by third cleaning.

8. The method of removing polyimide layers according to claim 7, wherein The step of removing the polyimide layer on the wafer surface by third cleaning comprises: The third cleaning is a polar similar compatible principle cleaning, and the wafer is cleaned by a polar solvent for a third preset time; removing the polar solvent on the wafer surface after the third cleaning.

9. The method of removing polyimide layers according to claim 8, wherein The polar solvent is at least one of N-methyl pyrrolidone, dimethyl sulfoxide and N,N-dimethylacetamide.

10. The method for removing a polyimide layer according to any one of claims 1 to 5, characterized in that, After the step of second cleaning the wafer after the first cleaning, the method further comprises: checking whether the wafer surface is left with a polyimide layer, and if the wafer surface is left with a polyimide layer, continuing to etch, first clean and second clean the wafer until the wafer surface is not left with a polyimide layer; if the wafer surface is not left with a polyimide layer, obtaining a wafer without a polyimide layer.

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