Wafer cleaning machine and wafer cleaning method

Abstract

The application discloses a wafer cleaning machine and a wafer cleaning method, and relates to the technical field of semiconductors. The wafer cleaning machine comprises a bearing table used for bearing a to-be-cleaned wafer formed with a contact hole, wherein the contact hole is provided with a particle; a first cleaning module used for spraying a mixed cleaning agent into the contact hole, and the particle is located in the mixed cleaning agent; the mixed cleaning agent comprises a polyol cleaning agent and an isocyanate cleaning agent; a heating module used for providing a heating environment, so that the mixed cleaning agent in the contact hole forms a polyurethane cleaning product which adsorbs the particle; and a second cleaning module used for spraying a preset cleaning agent into the contact hole, so as to remove the polyurethane cleaning product. The wafer cleaning machine can realize cleaning of the to-be-cleaned wafer and avoid residue of the particle.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor technology, and in particular to a wafer cleaning machine and a wafer cleaning method. Background Technology

[0002] With the development of integrated circuit technology, the key dimensions of semiconductor structures are shrinking, the integration level of semiconductor structures is increasing, the aspect ratio of contact holes in semiconductor structures is gradually increasing, and the difficulty of cleaning by-products in contact holes is increasing.

[0003] In related technologies, a combination of dry and wet cleaning methods is used to clean contact holes. If the cleaning time is too long, it will change the morphology of the contact holes. If the cleaning time is too short, it will not be able to completely remove the by-products in the contact holes. The residual by-products will interfere with the filling process of forming conductive plugs in the contact holes, increase the contact resistance of the conductive plugs, and make the contact resistance unstable, thus affecting the performance of the semiconductor structure. Summary of the Invention

[0004] This disclosure provides a wafer cleaning machine and a wafer cleaning method that can optimize the cleaning of contact holes and improve the performance of semiconductor structures.

[0005] A wafer cleaning machine, comprising:

[0006] A support stage for holding a wafer to be cleaned with contact holes containing particles;

[0007] A first cleaning module is used to spray a mixed cleaning agent into the contact hole, wherein the particles are located in the mixed cleaning agent; the mixed cleaning agent includes a polyol cleaning agent and an isocyanate cleaning agent.

[0008] A heating module is used to provide a heating environment so that the mixed cleaning agent in the contact hole forms a polyurethane cleaning material with the adsorbed particles.

[0009] The second cleaning module is used to spray a preset cleaning agent into the contact hole to remove the polyurethane cleaning agent.

[0010] In one embodiment, the first cleaning module includes:

[0011] A mixing module is used to mix the polyol cleaning agent and the isocyanate cleaning agent to obtain the mixed cleaning agent;

[0012] The spray module, connected to the mixing module, includes multiple spray holes for spraying the mixed cleaning agent.

[0013] In one embodiment, the polyol cleaning agent comprises polyol, silicone oil, and amine catalyst; the isocyanate cleaning agent comprises isocyanate and dichloromethane;

[0014] The amine catalyst is used to catalyze the reaction between the polyol and the isocyanate.

[0015] In one embodiment, the amine catalyst includes at least one of triethanolamine, 4-dimethylaminopyridine, and triethylamine.

[0016] In one embodiment, the wafer cleaning machine further includes:

[0017] A cleaning tank containing an acidic cleaning agent is provided, wherein when the wafer to be cleaned is located in the acidic cleaning agent, the acidic cleaning agent is used to increase the adsorption of the polyurethane cleaning agent in the contact hole.

[0018] In one embodiment, the acidic cleaning agent includes ethanol, triethoxyvinylsilane, tetraethyl orthosilicate, and acetic acid.

[0019] In one embodiment, the preset cleaning agent includes isopropanol or deionized water.

[0020] A wafer cleaning method, comprising:

[0021] A wafer to be cleaned is provided, wherein the contact holes have particles formed therein;

[0022] A mixed cleaning agent is sprayed into the contact hole, and the particles are located in the mixed cleaning agent; the mixed cleaning agent includes a polyol cleaning agent and an isocyanate cleaning agent;

[0023] A heating environment is provided so that the mixed cleaning agent in the contact hole forms a polyurethane cleaning material with the adsorbed particles.

[0024] A preset cleaning agent is sprayed into the contact hole to remove the polyurethane cleaning agent.

[0025] In one embodiment, spraying the mixed cleaning agent into the contact hole includes:

[0026] The polyol cleaning agent and the isocyanate cleaning agent are mixed to obtain the mixed cleaning agent;

[0027] The mixed cleaning agent is sprayed into the contact hole.

[0028] In one embodiment, the wafer cleaning method further includes:

[0029] The wafer to be cleaned, which has the polyurethane cleaning agent in the contact hole, is placed in an acidic cleaning agent;

[0030] The acidic cleaning agent is used to increase the adsorption of the polyurethane cleaning agent.

[0031] An unexpected effect of this application is:

[0032] In the aforementioned wafer cleaning machine and method, a mixed cleaning agent comprising polyol and isocyanate cleaning agents is sprayed into the contact holes of the wafer to be cleaned. Particles in the contact holes are contained within the mixed cleaning agent. A heating environment is provided, causing the mixed cleaning agent in the contact holes to form a polyurethane cleaning material adsorbing the particles. Particles in contact holes with different aspect ratios can all be adsorbed into the polyurethane cleaning material. A preset cleaning agent is then sprayed into the contact holes to remove the polyurethane cleaning material. The particles in the contact holes are removed along with the polyurethane cleaning material, thus preventing particle residue in the contact holes. Furthermore, the cleaning of the wafer to be cleaned does not affect the morphology of the contact holes, and the resistance of the plugs subsequently formed in the contact holes is stable and unaffected by particles, improving the performance of the semiconductor structure corresponding to the wafer to be cleaned. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments or related technologies of this disclosure, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is one of the structural schematic diagrams of the wafer cleaning machine in the embodiments of this application;

[0035] Figure 2 This is a cross-sectional schematic diagram of the wafer to be cleaned in an embodiment of this application;

[0036] Figure 3 This is the second schematic diagram of the structure of the wafer cleaning machine in the embodiments of this application;

[0037] Figure 4 This is a cross-sectional schematic diagram of a wafer to be cleaned containing a mixed cleaning agent in an embodiment of this application;

[0038] Figure 5 This is a schematic cross-sectional view of the wafer to be cleaned after the formation of the polyurethane cleaning material in an embodiment of this application.

[0039] Figure 6 This is a cross-sectional schematic diagram of the wafer to be cleaned in the acidic cleaning agent in an embodiment of this application;

[0040] Figure 7 This is a schematic cross-sectional view of the wafer to be cleaned after the polyurethane cleaning agent has been removed in an embodiment of this application.

[0041] Figure 8 This is a schematic flowchart of the wafer cleaning method in the embodiments of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 100 wafer to be cleaned; 102 support platform; 104 first cleaning module; 106 heating module; 108 second cleaning module; 110 mixed cleaning agent; 112 control module; 114 polyurethane cleaning agent; 202 contact hole; 204 particles; 206 mixing module; 208 spraying module. Detailed Implementation

[0044] To facilitate understanding of the embodiments of this disclosure, a more complete description of the embodiments of this disclosure will be provided below with reference to the accompanying drawings. Preferred embodiments of the embodiments of this disclosure are shown in the drawings. However, the embodiments of this disclosure can be implemented in many different forms and are not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0045] 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 embodiments of this disclosure belong. The terminology used herein in the description of embodiments of this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0046] In the description of the embodiments of this disclosure, it should be understood that the terms "upper", "lower", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the method or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0047] In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined. In the description of this disclosure, "several" means at least one, such as one, two, etc., unless otherwise expressly and specifically defined.

[0048] As used herein, the terms “substrate” and “base” refer to and include the base material or construction of the semiconductor structures described in this disclosure. A substrate may be a semiconductor substrate, a base semiconductor layer on a support structure, a metal electrode, or a semiconductor substrate having one or more layers, structures, or regions formed thereon. A substrate may be a conventional silicon substrate or other bulk substrate comprising layers of semiconductor material.

[0049] In integrated circuit manufacturing technology, filling contact holes with conductive layers is a crucial interconnection technique. In related technologies, contact holes are formed by etching on the substrate. Because these contact holes are numerous and deep, the byproducts formed within them after etching are difficult to remove. These byproducts are mostly residual oxides and polymers, which can interfere with the subsequent filling process of forming the conductive layer within the contact holes, resulting in high and unstable contact resistance of the conductive layer.

[0050] In related technologies, a combination of dry and wet cleaning methods is used to clean contact holes. Wet cleaning agents include DIW (dissolved water), APM, and H2O2. However, this method cannot completely remove oxides and polymers remaining at the bottom of contact holes with large aspect ratios. These residual oxides and polymers can affect the performance of the semiconductor structure. While increasing the cleaning time can improve the cleaning effect, wet cleaning is isotropic, and increasing the cleaning time will alter the morphology of the contact holes, affecting the performance of the semiconductor structure.

[0051] To address the aforementioned issues, this application provides a wafer cleaning machine that enhances the cleaning effect of contact holes and improves the performance of semiconductor structures without altering the morphology of the contact holes.

[0052] Figure 1 This is one of the structural schematic diagrams of the wafer cleaning machine in the embodiments of this application. Figure 2 This is a cross-sectional schematic diagram of the wafer to be cleaned in an embodiment of this application. See also... Figure 1 and Figure 2 In this embodiment, a wafer cleaning machine is provided, including: a support platform 102, a first cleaning module 104, a heating module 106, and a second cleaning module 108.

[0053] The support stage 102 is used to support the wafer 100 to be cleaned, which has contact holes 202 formed therein. The wafer 100 to be cleaned has multiple contact holes 202, and the contact holes 202 contain particles 204.

[0054] As an example, the wafer 100 to be cleaned can be a substrate, and the contact hole 202 is a through hole formed by etching the substrate. The wafer 100 to be cleaned can also be a substrate with a device layer formed on its surface, and the contact hole 202 is a through hole formed by etching the device layer. As an example, the device layer includes a conductive layer made of conductive material and / or an insulating layer made of insulating material.

[0055] For example, the substrate constituent materials include undoped single-crystal silicon, doped single-crystal silicon, silicon-on-insulator (SOI), silicon-on-insulator stacked (SSOI), silicon-on-insulator stacked (S-SiGeOI), silicon-on-insulator (SiGeOI), and germanium-on-insulator (GeOI), gallium arsenide (GaAs), gallium nitride (GaN), silicon carbide (SiC), or any combination thereof. As an example, in this embodiment, the substrate constituent material is selected as single-crystal silicon.

[0056] As an example, the contact hole 202 can be used to fill and form a conductive plug to connect conductive interconnects on opposite sides of the contact hole 202; the contact hole 202 can also be used to fill and form an insulating structure.

[0057] As an example, multiple contact holes 202 are spaced apart. In a first direction X perpendicular to the wafer 100 to be cleaned, the depths of the multiple contact holes 202 can be the same or different. In a second direction Y parallel to the wafer 100 to be cleaned, the dimensions of the multiple contact holes 202 can be the same or different.

[0058] Particle 204 is a byproduct of forming contact hole 202. As an example, particle 204 may be located at the bottom of contact hole 202 or on the sidewall of contact hole 202. Exemplarily, the material of particle 204 includes at least one of oxides, polymers, organic matter, and liquid residues.

[0059] The first cleaning module 104 is used to spray a mixed cleaning agent into the contact hole 202, with particles 204 located in the mixed cleaning agent; wherein the mixed cleaning agent includes a polyol cleaning agent and an isocyanate cleaning agent. As an example, the mixed cleaning agent is a mixture of a polyol cleaning agent and an isocyanate cleaning agent.

[0060] As an example, no chemical reaction occurs between the mixed cleaning agent and the wafer 100 to be cleaned. The particles 204 in the contact hole 202 are located within the mixed cleaning agent; that is, the particles 204 are contained within the mixed cleaning agent. The mixed cleaning agent can either completely fill the contact hole 202 or fill only the portion of the contact hole 202 containing the particles 204. Setting the mixed cleaning agent to fill the contact hole 202 facilitates control of the dosage of the mixed cleaning agent and facilitates the removal of subsequent polyurethane cleaning residue.

[0061] The heating module 106 is used to provide a heating environment. The mixed cleaning agent in the contact hole 202 reacts in the heating environment to form a polyurethane cleaning agent. The polyurethane cleaning agent has a certain viscosity, and the particles 204 in the contact hole 202 are adsorbed into the polyurethane cleaning agent.

[0062] The polyurethane cleaning agent formed by the reaction of the mixed cleaning agent has a porous structure, which can capture particles 204 in the contact hole 202 within the pores. At the same time, the movement of the polyurethane cleaning agent increases the soft mechanical abrasion of the inner wall of the contact hole 202. Compared with solvent cleaning, it can effectively remove residues deep within the contact hole 202 and in the contact hole 202, effectively preventing changes in the morphology of the contact hole 202 during the cleaning process.

[0063] The second cleaning module 108 is used to spray a preset cleaning agent into the contact hole 202 to remove the polyurethane cleaning material in the contact hole 202; wherein, the particles 204 adsorbed in the polyurethane cleaning material are moved out of the contact hole 202 along with the polyurethane cleaning material, thereby cleaning the particles 204 in the contact hole 202.

[0064] In the aforementioned wafer cleaning machine, the first cleaning module 104 sprays a mixed cleaning agent, comprising a polyol cleaning agent and an isocyanate cleaning agent, into the contact holes 202 of the wafer 100 to be cleaned. Particles 204 in the contact holes 202 are located within the mixed cleaning agent. The heating module 106 provides a heating environment, causing the mixed cleaning agent in the contact holes 202 to form a polyurethane cleaning material adsorbed with the particles 204. Particles 204 in contact holes 202 with different aspect ratios can all be adsorbed into the polyurethane cleaning material. The second cleaning module 108 sprays a preset cleaning agent into the contact holes 202 to remove the polyurethane cleaning material. The particles 204 in the contact holes 202 are removed along with the polyurethane cleaning material, thus preventing particle 204 residue in the contact holes 202. Furthermore, the cleaning of the wafer 100 to be cleaned does not affect the morphology of the contact holes 202. The resistance of the conductive plugs subsequently formed in the contact holes 202 is stable and unaffected by the particles 204, improving the performance of the semiconductor structure corresponding to the wafer 100 to be cleaned.

[0065] Figure 3 This is the second schematic diagram of the wafer cleaning machine in the embodiments of this application. Figure 4 This is a schematic cross-sectional view of a wafer to be cleaned containing a mixed cleaning agent, as shown in the embodiments of this application. Figure 3 and Figure 4 In some embodiments, the first cleaning module 104 includes a mixing module 206 and a spraying module 208.

[0066] The mixing module 206 is used to separately obtain polyol cleaning agent and isocyanate cleaning agent, and mix the obtained polyol cleaning agent and isocyanate cleaning agent to form mixed cleaning agent 110. Through the mixing module 206, the polyol cleaning agent and isocyanate cleaning agent are mixed to obtain a uniformly mixed cleaning agent 110.

[0067] The spraying module 208 is connected to the mixing module 206 to obtain the mixed cleaning agent 110. The spraying module 208 includes a plurality of spaced-apart spray holes, each spray hole being used to spray the mixed cleaning agent 110 into the contact holes 202 of the wafer 100 to be cleaned. Through the spray holes of the spraying module 208, the mixed cleaning agent is uniformly sprayed into each contact hole 202 of the wafer 100 to be cleaned, avoiding the absence of mixed cleaning agent in the contact holes 202.

[0068] As an example, the spray module 208 includes a nozzle with spray holes spaced apart on the nozzle. The spray holes are connected to a mixing module 206 containing a mixed cleaning agent, so as to spray the mixed cleaning agent in the mixing module 206 into the contact holes of the wafer 100 to be cleaned. For example, the spray module 208 has a shower-shaped nozzle to ensure that the mixed cleaning agent is sprayed evenly into the contact holes 202, resulting in a more uniform flow of the mixed cleaning agent.

[0069] In some embodiments, the polyol cleaning agent comprises a polyol, silicone oil, and an amine catalyst; the isocyanate cleaning agent comprises an isocyanate and dichloromethane; wherein the amine catalyst is used to catalyze the reaction between the polyol and the isocyanate. It is understood that in a heated environment, the isocyanate and polyol react to form a polyurethane cleaning agent. The presence of the isocyanate increases its hardness, facilitating particle adsorption and subsequent discharge of the polyurethane cleaning agent. It is understood that the polyurethane cleaning agent is a viscous foam, and dichloromethane can increase foam formation, facilitating particle adsorption 204.

[0070] For example, in polyol cleaning agents, the molar ratio of polyol, silicone oil, and amine catalyst includes 1:7 to 10:10 to 200. For example, in isocyanate cleaning agents, the molar ratio of isocyanate and dichloromethane includes 2:5.

[0071] As an example, amine catalysts include at least one of triethanolamine, 4-dimethylaminopyridine, and triethylamine.

[0072] See Figure 3 As an example, the wafer cleaning machine also includes a control module 112; the control module 112 is connected to the first cleaning module 104, the heating module 106 and the second cleaning module 108 respectively.

[0073] The control module 112 is used to control the first cleaning module 104 to acquire and mix polyol cleaning agent and isocyanate cleaning agent when the bare wafer 100 to be cleaned is located on the support stage 102, and to spray the mixed cleaning agent 110 into the contact hole 202 of the wafer 100 to be cleaned.

[0074] The control module 112 is also used to control the heating module 106 to provide a heating environment to the wafer 100 to be cleaned in the contact hole 202 containing the mixed cleaning agent 110, so that the mixed cleaning agent 110 reacts to form a polyurethane cleaning material adsorbed with particles 204.

[0075] The control module 112 is also used to control the second cleaning module 108 to spray a preset cleaning agent into the contact hole 202 containing polyurethane cleaning material on the wafer 100 to be cleaned, so as to remove the polyurethane cleaning material with adsorbed particles 204 in the contact hole 202 through the preset cleaning agent, thereby cleaning the wafer 100 to be cleaned.

[0076] As an example, control module 112 includes a controller.

[0077] Figure 5 This is a schematic cross-sectional view of the wafer to be cleaned after the formation of the polyurethane cleaning material in an embodiment of this application. See also... Figure 5 The heating module 106 provides a heating environment for the wafer 100 to be cleaned, which contains a mixed cleaning agent in the contact hole 202; the mixed cleaning agent in the contact hole 202 reacts in the heating environment to form a foam-like polyurethane cleaning agent 114; wherein, the particles 204 are adsorbed in the foam-like polyurethane cleaning agent 114.

[0078] As an example, the temperature of the heating environment provided by the heating module 106 includes 100 degrees to 150 degrees, such as 100 degrees, 120 degrees, 150 degrees, etc. For example, the reaction time of the wafer 100 to be cleaned with the mixed cleaning agent in the heating environment includes 10 seconds to 15 seconds, such as 10 seconds, 12 seconds, 13 seconds, 15 seconds, etc.

[0079] Figure 6 This is a schematic cross-sectional view of the wafer to be cleaned in the acidic cleaning agent in an embodiment of this application. See also... Figure 6 In some embodiments, the wafer cleaning machine further includes a cleaning tank containing an acidic cleaning agent 116. When the wafer 100 to be cleaned is located in the acidic cleaning agent 116 in the cleaning tank, the acidic cleaning agent 116 is used to increase the adsorption of the polyurethane cleaning agent 114 in the contact hole 202.

[0080] Soaking in acidic cleaning agent 116 increases the viscosity of polyurethane cleaning agent 114, making it more effective at adsorbing particles 204 and enhancing its cleaning ability in contact holes 202. For example, it increases the adsorption capacity for organic matter, effectively cleaning residual oxides, polymers, etc. in contact holes 202.

[0081] The particles 204 adsorbed in the polyurethane cleaning agent 114 detach from the wafer 100 to be cleaned as the polyurethane cleaning agent 114 is removed, preventing surface wear of the wafer 100 caused by liquid scouring. This also allows for better cleaning of the contact holes 202 with large aspect ratios in the wafer 100. The cleaning process of the wafer 100 does not affect the morphology of the contact holes 202, further improving the electrical performance of the semiconductor structure corresponding to the wafer 100. Furthermore, compared to cleaning the wafer 100 using dry or wet cleaning methods, this application offers shorter cleaning time, and the cleaning capability is unaffected by the morphology and size of the contact holes 202, making it suitable for different types of semiconductor structures.

[0082] As an example, a wafer 100 to be cleaned with polyurethane cleaning agent 114 in contact hole 202 is immersed in acidic cleaning agent 116 for a time ranging from 10 minutes to 20 minutes, such as 10 minutes, 12 minutes, 13 minutes, 15 minutes, 17 minutes, 20 minutes, etc.

[0083] As examples, acidic cleaning agents include ethanol, triethoxyvinylsilane (TEVS), tetraethyl orthosilicate, and acetic acid.

[0084] For example, in an acidic cleaning agent, the molar ratio of ethanol, triethoxyvinylsilane, tetraethyl orthosilicate, and acetic acid includes 30:1:1.

[0085] As an example, the wafer cleaning machine further includes: a moving module; the moving module is used to move the wafer 100 to be cleaned, which has polyurethane cleaning agent 114 in the contact hole 202, into the cleaning tank; the moving module is also used to remove the wafer 100 to be cleaned from the cleaning tank in the acid cleaning agent 116. As an example, the moving module moves the wafer 100 to be cleaned in the acid cleaning agent 116 onto the support stage 102.

[0086] Figure 7 This is a schematic cross-sectional view of the wafer to be cleaned after the polyurethane cleaning agent has been removed in an embodiment of this application. See also: Figure 7 As an example, the second cleaning module 108 is used to spray a preset cleaning agent onto the wafer 100 to be cleaned after it has been removed from the cleaning tank, so as to remove the polyurethane cleaning material in the contact hole 202 by the preset cleaning agent and thus clean the wafer 100 to be cleaned.

[0087] It is understandable that by using a preset cleaning agent, the polyurethane cleaning material containing particles 204 adsorbed in the contact hole 202 can be removed from the contact hole 202, thereby achieving the cleaning of the wafer 100 to be cleaned.

[0088] As an example, the default cleaning agents include isopropanol or deionized water.

[0089] As an example, the cleaning of the wafer 100 to be cleaned is performed in a sealed environment. For example, the stage 102 is disposed in the sealed chamber of the wafer cleaning machine.

[0090] Based on the same inventive concept, this application also provides a wafer cleaning method. The solution provided by this wafer cleaning method is similar to the solution described in the above-mentioned wafer cleaning machine. The parts that are the same as or corresponding to the embodiments in the above-mentioned wafer cleaning machine will not be described in detail below.

[0091] Figure 8 This is a schematic flowchart of the wafer cleaning method in an embodiment of this application. See also... Figure 8 In this embodiment, a wafer cleaning method is provided, including:

[0092] S102 provides a wafer to be cleaned with contact holes formed therein, the contact holes containing particles.

[0093] S104, the mixed cleaning agent is sprayed into the contact hole, and the particles are located in the mixed cleaning agent.

[0094] Specifically, the mixed cleaning agent is sprayed into the contact holes of the wafer to be cleaned; wherein the particles in the contact holes are located in the mixed cleaning agent, which includes polyol cleaning agent and isocyanate cleaning agent.

[0095] S106 provides a heating environment that causes the mixed cleaning agent in the contact hole to form a polyurethane cleaning material with adsorbed particles.

[0096] S108, spray the preset cleaning agent into the contact hole to remove polyurethane cleaning residue.

[0097] In the aforementioned wafer cleaning method, a mixed cleaning agent comprising a polyol cleaning agent and an isocyanate cleaning agent is sprayed into the contact holes of the wafer to be cleaned. Particles in the contact holes are contained within the mixed cleaning agent. A heating environment is provided, causing the mixed cleaning agent in the contact holes to form a polyurethane cleaning material adsorbing the particles. Particles in contact holes with different aspect ratios can all be adsorbed into the polyurethane cleaning material. A pre-selected cleaning agent is then sprayed into the contact holes to remove the polyurethane cleaning material. The particles in the contact holes are removed along with the polyurethane cleaning material, thus preventing particle residue in the contact holes. Furthermore, the cleaning of the wafer to be cleaned does not affect the morphology of the contact holes, and the resistance of the plugs subsequently formed in the contact holes is stable and unaffected by particles, improving the performance of the semiconductor structure corresponding to the wafer to be cleaned.

[0098] In one embodiment, spraying the mixed cleaning agent into the contact hole includes: mixing a polyol cleaning agent and an isocyanate cleaning agent to obtain the mixed cleaning agent; and spraying the mixed cleaning agent into the contact hole.

[0099] As an example, a polyol cleaning agent and an isocyanate cleaning agent are obtained separately; the obtained polyol cleaning agent and isocyanate cleaning agent are then mixed to form a mixed cleaning agent. The formed mixed cleaning agent is then sprayed into the contact holes of the wafer to be cleaned.

[0100] For example, the time interval between the formation of the mixed cleaning agent and the spraying of the mixed cleaning agent is less than a first preset value; wherein, the first preset value is the reaction time of the polyol cleaning agent and the isocyanate cleaning agent under static conditions. This setting can prevent the mixed cleaning agent from reacting before being sprayed onto the wafer to be cleaned, thus avoiding affecting the cleaning effect of the wafer 100 to be cleaned.

[0101] In one embodiment, the wafer cleaning method further includes: placing the wafer to be cleaned, which has a polyurethane cleaning agent in the contact hole, in an acidic cleaning agent; wherein the acidic cleaning agent is used to increase the adsorption of the polyurethane cleaning agent.

[0102] As an example, a wafer with polyurethane cleaning agent in its contact holes is placed in an acidic cleaning agent for a preset time, and then removed from the acidic cleaning agent. The preset time, for example, includes 10 to 20 minutes, such as 10 minutes, 12 minutes, 13 minutes, 15 minutes, 17 minutes, 20 minutes, etc.

[0103] Soaking in acidic cleaning agent 116 increases the viscosity of polyurethane cleaning agent 114, making it more effective at adsorbing particles 204 and enhancing its cleaning ability in contact holes 202. For example, it increases the adsorption capacity for organic matter, effectively cleaning residual oxides, polymers, etc. in contact holes 202.

[0104] The particles 204 adsorbed in the polyurethane cleaning agent 114 detach from the wafer 100 to be cleaned as the polyurethane cleaning agent 114 is removed, preventing surface wear of the wafer 100 caused by liquid scouring. This also allows for better cleaning of the contact holes 202 with large aspect ratios in the wafer 100. The cleaning process of the wafer 100 does not affect the morphology of the contact holes 202, further improving the electrical performance of the semiconductor structure corresponding to the wafer 100. Furthermore, compared to cleaning the wafer 100 using dry or wet cleaning methods, this application offers shorter cleaning time, and the cleaning capability is unaffected by the morphology and size of the contact holes 202, making it suitable for different types of semiconductor structures.

[0105] As an example, spraying a preset cleaning agent into the contact hole to remove polyurethane cleaning material includes: spraying the preset cleaning agent into the wafer 100 to be cleaned after removing the acidic cleaning agent, so as to remove the polyurethane cleaning material in the contact hole 202 by the preset cleaning agent, thereby cleaning the wafer 100 to be cleaned. In this way, the cleaning effect of the wafer to be cleaned can be improved.

[0106] It should be understood that, although Figure 8 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 8 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0107] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The above-described embodiments are merely illustrative of several implementation methods of the present disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present disclosure embodiments, and these modifications and improvements all fall within the protection scope of the present disclosure embodiments.

Claims

1. A wafer cleaning machine, characterized in that, include: A support stage for holding a wafer to be cleaned with contact holes containing particles; A first cleaning module is used to spray a mixed cleaning agent into the contact hole, wherein the particles are located in the mixed cleaning agent; the mixed cleaning agent includes a polyol cleaning agent and an isocyanate cleaning agent. A heating module is used to provide a heating environment so that the mixed cleaning agent in the contact hole forms a polyurethane cleaning material with the adsorbed particles. The second cleaning module is used to spray a preset cleaning agent into the contact hole to remove the polyurethane cleaning agent.

2. The wafer cleaning machine according to claim 1, characterized in that, The first cleaning module includes: A mixing module is used to mix the polyol cleaning agent and the isocyanate cleaning agent to obtain the mixed cleaning agent; The spray module, connected to the mixing module, includes multiple spray holes for spraying the mixed cleaning agent.

3. The wafer cleaning machine according to claim 1, characterized in that, The polyol cleaning agent comprises polyols, silicone oils, and amine catalysts; the isocyanate cleaning agent comprises isocyanates and dichloromethane. The amine catalyst is used to catalyze the reaction between the polyol and the isocyanate.

4. The wafer cleaning machine according to claim 3, characterized in that, The amine catalyst includes at least one of triethanolamine, 4-dimethylaminopyridine, and triethylamine.

5. The wafer cleaning machine according to claim 1, characterized in that, The wafer cleaning machine also includes: A cleaning tank containing an acidic cleaning agent is provided, wherein when the wafer to be cleaned is located in the acidic cleaning agent, the acidic cleaning agent is used to increase the adsorption of the polyurethane cleaning agent in the contact hole.

6. The wafer cleaning machine according to claim 5, characterized in that, The acidic cleaning agent includes ethanol, triethoxyvinylsilane, tetraethyl orthosilicate, and acetic acid.

7. The wafer cleaning machine according to claim 1, characterized in that, The preset cleaning agent includes isopropanol or deionized water.

8. A wafer cleaning method, characterized in that, include: A wafer to be cleaned is provided, wherein the contact holes have particles formed therein; A mixed cleaning agent is sprayed into the contact hole, and the particles are located in the mixed cleaning agent; the mixed cleaning agent includes a polyol cleaning agent and an isocyanate cleaning agent; A heating environment is provided so that the mixed cleaning agent in the contact hole forms a polyurethane cleaning material with the adsorbed particles. A preset cleaning agent is sprayed into the contact hole to remove the polyurethane cleaning agent.

9. The wafer cleaning method according to claim 8, characterized in that, The step of spraying the mixed cleaning agent into the contact hole includes: The polyol cleaning agent and the isocyanate cleaning agent are mixed to obtain the mixed cleaning agent; The mixed cleaning agent is sprayed into the contact hole.

10. The wafer cleaning method according to claim 8, characterized in that, The wafer cleaning method further includes: The wafer to be cleaned, which has the polyurethane cleaning agent in the contact hole, is placed in an acidic cleaning agent; The acidic cleaning agent is used to increase the adsorption of the polyurethane cleaning agent.

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