Tungsten etching method and preparation method of integrated circuit
By self-limiting reaction of the modifier with tungsten, it generates a modified layer and gradually removes it, which solves the problem that traditional etching technology is difficult to control the tungsten etching accuracy, and achieves precise control and efficient etching of tungsten, which is suitable for the manufacturing of future microelectronic devices.
Patent Information
- Application Number
- CN202311443491.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-01
- Publication Date
- 2025-05-06
AI Technical Summary
The continuous etching accuracy of tungsten by traditional wet etching and RIE dry etching is difficult to control, and the existing atomic layer etching method has poor selectivity for other materials, which cannot meet the future manufacturing needs of microelectronic devices.
By reacting with tungsten with a modifier, a self-restrained reaction modified layer is generated in the non-masked area of the tungsten surface, and the modified layer is gradually removed until a predetermined thickness of tungsten is etched away, so that precise control of tungsten is achieved.
This method can accurately control the etching depth of tungsten, reduce the load effect, take into account etching accuracy and efficiency, and has a high etching selection ratio for commonly used materials in integrated circuits.
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Figure CN119943669A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of integrated circuits, and in particular to a method for etching tungsten and a method for preparing an integrated circuit. Background Art
[0002] The integrated circuit field is always pursuing higher performance, lower power consumption and lower cost. Integrated circuit miniaturization technology can bring about overall improvement in these three aspects. As the size of integrated circuits continues to shrink, reliably producing smaller size graphics is one of the key technical challenges.
[0003] Although the current chip can be made smaller, it still faces the problem of processing accuracy. As one of the key processes for pattern formation, the traditional continuous etching technology cannot overcome the load effect, cannot control the etching rate, and the uniformity of etching cannot meet the manufacturing needs of future microelectronic devices.
[0004] In the prior art, conventional wet etching and RIE dry etching continuously etch tungsten, and the etching accuracy is difficult to control. Many methods of atomic layer etching of tungsten, such as using special means such as multi-step reactions to control the thickness of the modified layer, have a narrow rate adjustment range and poor selectivity for other materials. Summary of the invention
[0005] 1. Technical issues to be resolved
[0006] In view of the existing technical problems, the present disclosure provides a method for etching tungsten and a method for preparing an integrated circuit, which are used to at least partially solve the above technical problems.
[0007] (II) Technical solution
[0008] The present disclosure provides a method for etching tungsten, comprising: utilizing a modifier to react with tungsten to generate a modified layer of a first thickness in a non-masked area on the tungsten surface; removing the modified layer; repeatedly generating and removing the modified layer until tungsten of a second thickness is etched away; wherein the reaction of the modifier with tungsten is a self-limiting reaction, and the first thickness is one or more atomic layers thick.
[0009] Optionally, utilizing the modifier to react with tungsten to generate a modified layer of a first thickness in a non-masked area on the tungsten surface includes: controlling the reaction temperature of the modifier and tungsten to a first temperature to generate the modified layer within a first time; wherein the first temperature is -30 to 300°C, and within a preset time, the first thickness is positively correlated with the first temperature.
[0010] Optionally, the modifier includes: oxygen, ozone, oxygen-containing plasma, sulfur-containing plasma, chlorine, plasma containing non-fluorine-based halogen elements, and combined gases or plasmas thereof.
[0011] Optionally, removing the modified layer includes: using an etchant to dissolve the modified layer; wherein the etchant includes: an alkaline solution, hydrofluoric acid, BOE and an organic solvent.
[0012] Optionally, the alkaline solution includes: aqueous ammonia, TMAH, NaOH solution, KOH solution; the organic solvent includes: chloroform, methanol, ether, acetone, pyridine, glycerol, petroleum ether, ethanol, carbon tetrachloride, phosphorus oxychloride and benzene.
[0013] Optionally, removing the modified layer includes: heating the modified layer to a first temperature in an inert atmosphere or a vacuum environment to vaporize the modified layer; wherein the first temperature is at least 300° C.; the inert atmosphere includes: argon, helium, nitrogen and combinations thereof.
[0014] Optionally, after removing the modified layer, the method for etching tungsten further includes: cleaning the tungsten surface with a cleaning agent; wherein the cleaning agent is a liquid cleaning agent, including: water, high-purity deionized water, ethanol, acetone, isopropanol and a combination thereof; or the cleaning agent is a gaseous cleaning agent, including: argon, helium, nitrogen, hydrogen, water vapor and a combination thereof.
[0015] Optionally, the cleaning agent also includes: a mixture of a liquid cleaning agent and a surfactant and / or a hydrophobic coating additive; wherein the surfactant is an organic substance having a hydrophilic group at one end and a hydrophobic group at the other end, the hydrophilic group includes -OH, -COOH, and the hydrophobic group includes a hydrocarbon group; the hydrophobic coating additive is a silane reagent.
[0016] Optionally, the surfactant includes alcohol, aldehyde, ester and amine; the hydrophobic coating additive includes trimethylchlorosilane, TMSDMA, propyldimethylchlorosilane, alkyltrialkoxysilane, hexadecyltrimethoxysilane, tetraethoxysilane, 3-glycidyloxypropyltrimethoxysilane and silicone coupling agent R a Si(R b ) n X 3-n ; Among them, R a is a C1-24 straight-chain alkyl or branched alkyl, or an aromatic group separated from the silicon atom by 1 to 8 carbon atoms, R b It is a C1-6 straight chain alkyl or branched alkyl, n=0, 1, 2; X is a hydrolyzable group, and the hydrolyzable group includes halogen and alkoxy.
[0017] Another aspect of the present disclosure provides a method for preparing an integrated circuit, wherein the method for etching tungsten according to any embodiment of the present disclosure is used to etch tungsten in a silicon-based integrated circuit.
[0018] (III) Beneficial effects
[0019] Compared with the prior art, the method for etching tungsten and the method for preparing silicon-based integrated circuits provided by the present disclosure have at least the following beneficial effects:
[0020] (1) The method for etching tungsten disclosed in the present invention can precisely control the etching depth of tungsten by gradually generating and removing a modified layer with a thickness of one or more atomic layers through a self-limiting reaction. At the same time, since it is a self-limiting reaction, the reaction is sufficient, so that the etching process is not affected by the etching area and the aspect ratio of the pattern, thereby reducing the etching load effect.
[0021] (2) In the method for etching tungsten disclosed in the present invention, within a preset time, the thickness of the self-limiting layer formed by the reaction of the modifier and tungsten can be adjusted according to different temperatures, so that the etching of tungsten can be both accurate and efficient.
[0022] (3) The method for etching tungsten disclosed in the present invention can remove the modified layer by a liquid method or a gas method, has strong process compatibility, and some combination schemes have a high etching selectivity for materials commonly used in integrated circuits, such as silicon, silicon oxide, and titanium nitride. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:
[0024] Figure 1 A flow chart of a method for etching tungsten according to an embodiment of the present disclosure is schematically shown;
[0025] Figure 2 A flow chart of a method for etching tungsten according to a second embodiment of the present disclosure is schematically shown;
[0026] Figure 3 A flowchart of a method for etching tungsten according to a third embodiment of the present disclosure is schematically shown;
[0027] Figure 4 The flowchart of the method for etching tungsten according to the fourth embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION
[0028] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.
[0029] It should be noted that in the drawings or descriptions, similar or identical parts use the same figure numbers. The technical features in the various embodiments exemplified in the specification can be freely combined to form a new solution without conflict. In addition, each claim can be used as an embodiment alone or the technical features in each claim can be combined as a new embodiment. In the drawings, the shape or thickness of the embodiment can be expanded and simplified or conveniently indicated. Furthermore, the elements or implementations not shown or described in the drawings are in a form known to a person of ordinary skill in the art. In addition, although demonstrations of parameters containing specific values may be provided herein, it should be understood that the parameters do not need to be exactly equal to the corresponding values, but can be approximated to the corresponding values within an acceptable error tolerance or design constraint.
[0030] Unless there are technical obstacles or contradictions, the above-mentioned various embodiments of the present disclosure can be freely combined to form additional embodiments, and these additional embodiments are all within the protection scope of the present disclosure.
[0031] Although the present disclosure is described in conjunction with the accompanying drawings, the embodiments disclosed in the accompanying drawings are intended to exemplify the preferred embodiments of the present disclosure and should not be construed as limiting the present disclosure. The dimensional ratios in the accompanying drawings are merely illustrative and should not be construed as limiting the present disclosure.
[0032] Although some embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.
[0033] Figure 1 The flowchart of the method for etching tungsten according to an embodiment of the present disclosure is schematically shown.
[0034] According to the embodiments of the present disclosure, Figure 1 As shown, the method of etching tungsten includes, for example:
[0035] S110, using a modifier to react with tungsten to generate a modified layer of a first thickness in a non-masked area on the tungsten surface, wherein the reaction between the modifier and tungsten is a self-limiting reaction, and the first thickness is one or more atomic layers thick.
[0036] S120, removing the modified layer.
[0037] S130, repeatedly generating and removing the modified layer until tungsten having a second thickness is etched away.
[0038] For example, a modifying agent is used to chemically react with tungsten to form a modified layer with a thickness of several atomic layers on the non-masked area of the tungsten surface, and the modified layer is removed. The steps of forming the modified layer using the modifying agent and removing the modified layer are repeated until a tungsten layer of a predetermined thickness is etched at the selected area. The thickness of the modified layer is, for example, 0.5 to 10 nm.
[0039] Since the reaction between the modifier and tungsten is self-limiting, the reaction between the modifier and the selected area of the tungsten layer on its surface, at least for a period of time, the rate of increase of the thickness of the modified layer decreases as the time of the reaction between tungsten and the modifier increases. Furthermore, the modified layer formed by the reaction of several atomic layers at the selected area of the tungsten layer surface with the modifier prevents the selected area of the surface (i.e., the exposed tungsten layer) from continuing to react with the modifier. That is, the modifier reacts with the selected area of the tungsten layer surface until the thickness of the modified layer reaches the saturation thickness.
[0040] The formation process of the modified layer and the removal process of the modified layer are both isotropic.
[0041] According to an embodiment of the present disclosure, the modifier includes, for example, oxygen, ozone, oxygen-containing plasma, sulfur-containing plasma, chlorine, halogen-containing plasma, and combined gases or plasmas thereof.
[0042] For example, the modifier can be a plasma containing non-fluorine-based halogen elements such as oxygen, ozone, oxygen-containing plasma, sulfur-containing plasma, chlorine or chlorine-containing plasma, bromine-containing plasma, or a combination of several of them. Furthermore, the generated modified layer includes halides such as tungsten oxides, sulfides, and chlorides.
[0043] According to an embodiment of the present disclosure, using a modifier to react with tungsten to generate a modified layer of a first thickness in a non-masked area on the tungsten surface includes, for example, controlling the reaction temperature of the modifier and tungsten to be a first temperature to generate the modified layer within a first time. The first temperature is, for example, -30 to 300°C, and the first time is the time taken for self-limitation to reach saturation. Within the preset time, the first thickness is positively correlated with the first temperature.
[0044] For example, the thickness of the modified layer can be adjusted by changing the substrate temperature. When the substrate is heated, the temperature of the tungsten layer will also increase, thereby accelerating the reaction rate of tungsten and the modifier. In the initial stage of the reaction between the surface of the tungsten layer and the modifier, the reaction rate will be relatively fast, and since the rate of increase of the thickness of the modified layer decreases with the increase of the reaction time with the modifier, as the reaction proceeds, the reaction rate will drop rapidly and reach saturation within a certain range of process conditions. Among them, different reaction temperatures correspond to different thicknesses of the modified layer that reach saturation. Therefore, the etching method of the embodiment of the present disclosure can flexibly increase the etching rate under the condition of good control of the etching amount or thickness.
[0045] Since the thickness of the modified layer formed is only a few atomic layers thick and the reaction is self-limiting, the reaction between the tungsten surface and the modifier is almost stopped after the thickness of the modified layer formed on the surface of the tungsten layer reaches the saturation thickness. Therefore, the etching method of the embodiment of the present disclosure can well control the etching thickness and is conducive to more accurately controlling the etching accuracy.
[0046] Figure 2 The flowchart of the method for etching tungsten according to the second embodiment of the present disclosure is schematically shown.
[0047] According to the embodiments of the present disclosure, Figure 2 As shown, the modified layer can be removed by dissolving. According to the chemical properties of the modified layer, removing the modified layer includes, for example, dissolving the modified layer by using an etchant. The etchant includes, for example, alkaline solution, hydrofluoric acid, BOE and organic solvent. The alkaline solution includes, for example, ammonia water, TMAH (tetramethylammonium), NaOH solution, KOH solution. The organic solvent includes, for example, chloroform, methanol, ether, acetone, pyridine, glycerol, petroleum ether, ethanol, carbon tetrachloride, phosphorus oxychloride and benzene.
[0048] For example, BOE (Buffered Oxide Etch) is a buffered etching solution, which can be prepared by mixing HF and NH 4 F in different proportions.
[0049] According to the embodiments of the present disclosure, Figure 2 As shown, after removing the modified layer, the method for etching tungsten also includes, for example, cleaning the tungsten surface with a cleaning agent. The cleaning agent may be a liquid cleaning agent, including water, high-purity deionized water, ethanol, acetone, isopropanol, and combinations thereof. Alternatively, the cleaning agent may be a gaseous cleaning agent, including argon, helium, nitrogen, hydrogen, water vapor, and combinations thereof.
[0050] For example, after the modified layer is dissolved, a cleaning agent is used to clean the substrate. After the formation of the modified layer and the removal of the modified layer are completed in sequence, there will be residual modifiers, residual etchants and / or various residual products in the reaction on the surface. Therefore, after the formation of the modified layer and the removal of the modified layer are completed in sequence, it is necessary to use a cleaning agent to clean the surface to remove these pollutants, reduce cross contamination between different steps before and after, and ensure the processing quality of the tungsten surface.
[0051] For example, the cleaning agent used may include water, high-purity deionized water, ethanol, acetone, isopropanol or a liquid of a combination thereof, or argon, helium, nitrogen, hydrogen, water vapor or a gas of a combination thereof.
[0052] According to an embodiment of the present disclosure, the cleaning agent may also include, for example, a mixture of a liquid cleaning agent and a surfactant and / or a hydrophobic coating additive. The surfactant is an organic substance having a hydrophilic group at one end and a hydrophobic group at the other end and not reacting with tungsten, the hydrophilic group may include, for example, -OH and -COOH, and the hydrophobic group may include, for example, a hydrocarbon group. The hydrophobic coating additive may be, for example, a silane reagent.
[0053] For example, the cleaning agent used can also be a mixture of water, high-purity deionized water, ethanol, acetone, isopropanol or the liquid of several combinations thereof, etc. and a surfactant and / or a hydrophobic coating additive. Surfactant can reduce the surface tension of cleaning agent (water, high-purity deionized water, ethanol, acetone or isopropanol, etc.). Hydrophobic coating additive can reduce the affinity of cleaning agent (water, high-purity deionized water, ethanol, acetone or isopropanol, etc.) with the cleaned surface or can obtain surface hydrophobicity. Surfactant and / or hydrophobic coating additive can be added to cleaning agent (water, high-purity deionized water, ethanol, acetone or isopropanol, etc.).
[0054] For example, the surfactant can be alcohol, aldehyde, ester and amine. The hydrophobic coating additive can be, for example, trimethylchlorosilane (TMCS), TMSDMA ((CH3)3SiN(CH3)2), propyldimethylchlorosilane, alkyltrialkoxysilane, hexadecyltrimethoxysilane, tetraethoxysilane, 3-glycidyloxypropyltrimethoxysilane and silicone coupling agent R a Si(R b ) n X 3-n Among them, R a is a C1-24 straight-chain alkyl or branched alkyl, or an aromatic group separated from the silicon atom by 1 to 8 carbon atoms, R bIt is a short straight chain alkyl or branched alkyl of C1-6, n=0, 1, 2. X is a hydrolyzable group, and the hydrolyzable group includes, for example, halogen and alkoxy. When treating the solid surface, one end of the coupling agent reacts with the surfactant group, and the other end forms a monolayer oriented toward the air side, which has a significant water-repellent effect. The hydrophobic coating additive can be used for surface treatment or silanization of the cleaned surface.
[0055] Figure 3 The flowchart of the method for etching tungsten according to the third embodiment of the present disclosure is schematically shown.
[0056] According to the embodiments of the present disclosure, Figure 3 As shown, the modified layer can also be removed by gasification. Removing the modified layer includes, for example, heating the modified layer to a first temperature in an inert atmosphere or vacuum environment to gasify the modified layer. The first temperature is, for example, at least 300° C. The inert atmosphere includes, for example, argon, helium, nitrogen, and combinations thereof.
[0057] For example, by utilizing the property that the modified layer changes from solid to gas when the temperature is higher than a certain temperature, the temperature of the modified layer on the surface of the tungsten layer can be heated to above the vaporization temperature, and the modified layer can be turned into gas in an inert atmosphere or high vacuum, and be evacuated from the surface or directly evacuated along with the inert gas flow. An inert atmosphere is a gas environment that does not chemically react with tungsten, and does not generate solid substances or substances that can react with tungsten with the modified layer of tungsten. An inert atmosphere can be argon, helium, nitrogen, or a combination of several of them. For example, when forming a modified layer of WCl6, the temperature needs to be heated to 347°C to vaporize it.
[0058] According to the embodiments of the present disclosure, Figure 1 , Figure 2 , Figure 3 As shown, repeatedly generating and removing the modified layer until the second thickness of tungsten is etched away includes, for example, determining whether a tungsten layer of a predetermined thickness has been etched at the selected area, that is, whether a predetermined etching amount or etching thickness has been reached after one or more processes of forming and removing the modified layer.
[0059] If it is determined that the tungsten layer of a predetermined thickness has been etched in the selected area, the current processing process may be terminated.
[0060] If it is determined that the tungsten layer of the predetermined thickness has not been etched in the selected area, the process returns to the step of reacting the modifier with tungsten and performs a cyclic etching process until it is finally determined that the tungsten layer of the predetermined thickness has been etched in the selected area.
[0061] Figure 4 The flowchart of the method for etching tungsten according to the fourth embodiment of the present disclosure is schematically shown.
[0062] According to the embodiments of the present disclosure, Figure 4 As shown, the present disclosure can etch tungsten under heating conditions or under room temperature conditions.
[0063] For example, at 250°C, when O plasma (oxygen-containing plasma) is used to react with tungsten for 1 minute, the thickness of the surface modified tungsten oxide layer is about 4.9 nm. Then, NH3H2O is used to remove the tungsten oxide layer, and the reaction time is 1 minute. Then, cleaning and drying are performed, and etching is repeated until the predetermined etching thickness is reached.
[0064] For example, under normal temperature conditions, Cl Plasma (chlorine-containing plasma) is used to react with tungsten to obtain a surface modified layer of tungsten chloride. Then, the vaporized tungsten chloride is taken away by heating above 300°C in a N2 gas flow environment. The etching is repeated until a predetermined etching thickness is reached.
[0065] It is understandable that the thickness of the modified layer generated in the above embodiment is only exemplary. In actual production, the thickness of the modified layer generated is affected by various factors (such as the purity of tungsten, etc.), and may also be a thickness of other values.
[0066] Another aspect of the present disclosure provides a method for preparing an integrated circuit, wherein the tungsten in the integrated circuit is etched using the method for etching tungsten according to any embodiment of the present disclosure.
[0067] For example, according to certain combinations of the technical solutions of the embodiments of the present disclosure, a very high etching selectivity ratio can be achieved when etching tungsten for silicon and silicon dioxide materials commonly used in integrated circuits (such as those used in MEMS (Microelectro Mechanical Systems) devices), for example, reaching above 1:100.
[0068] In summary, the embodiments of the present disclosure provide a method for etching tungsten. By cyclically performing the operations of forming a modified layer and removing the modified layer, the etching thickness during tungsten processing is precisely controlled, and the etching efficiency can be improved by changing the modification reaction temperature.
[0069] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to a specific order or hierarchy.
[0070] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only reference directions of the drawings and are not intended to limit the scope of protection of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure. In addition, the shapes, sizes, and positional relationships of the components in the drawings do not reflect the actual sizes, proportions, and actual positional relationships.
[0071] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the attached claims, the disclosure is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the attached claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the disclosure.
[0072] In addition, the terms "first" and "second" are used for descriptive purposes only and are not to 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 disclosure, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. With respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", as explained in terms of "including," used as a transitional word in the claims. Any term "or" used in the specification of the claims is intended to mean "non-exclusive or".
[0073] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.
Claims
1. A method for etching tungsten, characterized in that: include: Using a modifying agent to react with tungsten to generate a modified layer of a first thickness on a non-masked area of the tungsten surface; removing the modified layer; Repeating the generation and removal of the modified layer until a second thickness of tungsten is etched away; The reaction between the modifier and tungsten is a self-limiting reaction, and the first thickness is one or more atomic layers thick.
2. The method according to claim 1, characterized in that The step of using a modifier to react with tungsten to generate a modified layer of a first thickness in a non-masked area on the surface of tungsten comprises: Controlling the reaction temperature of the modifier and tungsten to a first temperature so as to generate the modified layer within a preset time; Wherein, the first temperature is -30 to 300° C.; and Within the preset time, the first thickness is positively correlated with the first temperature.
3. The method according to claim 1, characterized in that The modifier includes: Oxygen, ozone, oxygen-containing plasma, sulfur-containing plasma, chlorine, plasma containing non-fluorine-based halogen elements, and combination gases or plasmas thereof.
4. The method according to claim 1, characterized in that: The removing of the modified layer comprises: dissolving the modified layer using an etchant; Wherein, the etchant includes: alkaline solution, hydrofluoric acid, BOE and organic solvent.
5. The method according to claim 4, characterized in that The alkaline solution comprises: Ammonia solution, TMAH, NaOH solution, KOH solution; The organic solvent includes: Chloroform, methanol, ether, acetone, pyridine, glycerol, petroleum ether, ethanol, carbon tetrachloride, phosphorus oxychloride and benzene.
6. The method according to claim 1, characterized in that The removing of the modified layer comprises: In an inert atmosphere or a vacuum environment, heating the modified layer to a first temperature to vaporize the modified layer; Wherein, the first temperature is at least 300°C; The inert atmosphere includes argon, helium, nitrogen and combinations thereof.
7. The method according to claim 1, characterized in that After removing the modified layer, the method further comprises: The tungsten surface is cleaned with a cleaning agent; Wherein, the cleaning agent is a liquid cleaning agent, including: water, high-purity deionized water, ethanol, acetone, isopropanol and a combination thereof; or The cleaning agent is a gaseous cleaning agent, including: argon, helium, nitrogen, hydrogen, water vapor and a combination thereof.
8. The method according to claim 7, characterized in that The cleaning agent also includes: A mixture of the liquid cleaning agent and a surfactant and / or a hydrophobic coating additive; Wherein, the surfactant is an organic substance having a hydrophilic group at one end and a hydrophobic group at the other end, wherein the hydrophilic group includes -OH and -COOH, and the hydrophobic group includes a hydrocarbon group; The hydrophobic coating additive is a silane reagent.
9. The method according to claim 8, characterized in that The surfactants include alcohols, aldehydes, esters and amines; The hydrophobic coating additives include trimethylchlorosilane, TMSDMA, propyldimethylchlorosilane, alkyltrialkoxysilane, hexadecyltrimethoxysilane, tetraethoxysilane, 3-glycidyloxypropyltrimethoxysilane and silicone coupling agent R a Si(R b ) n X 3-n ; Among them, R a is a C1-24 straight-chain alkyl or branched alkyl, or an aromatic group separated from the silicon atom by 1 to 8 carbon atoms, R b is a C1-6 straight chain alkyl or branched chain alkyl, n=0, 1, 2; X is a hydrolyzable group, and the hydrolyzable group includes halogen and alkoxy.
10. A method for preparing an integrated circuit, characterized in that: The tungsten in the silicon-based integrated circuit is etched using the method described in any one of claims 1 to 9.