Cleaning method and cleaning apparatus for contact holes

Abstract

The application provides a cleaning method and cleaning device for a contact hole, and belongs to the field of semiconductors. The cleaning method for the contact hole comprises the following steps: introducing a temperature-responsive reagent into the contact hole; controlling the temperature to convert the temperature-responsive reagent into a high-viscosity gel state, and the temperature-responsive reagent adheres to residues in the contact hole; controlling the temperature to solidify the temperature-responsive reagent in the gel state; and removing the solidified temperature-responsive reagent from the contact hole by a moving assembly. The method can ensure that the residues in the contact hole are completely removed, and the appearance of the contact hole is good.

Description

Technical Field

[0001] This invention belongs to the field of semiconductors, and particularly relates to a method and apparatus for cleaning contact holes. Background Technology

[0002] In integrated circuit manufacturing technology, filling contact holes with conductive layers is the most critical interconnection technology. Contact holes are formed through substrate etching. Due to the numerous and deep holes, byproducts form within the contact holes after etching, which are difficult to remove. These byproducts are mostly residual oxides, which interfere with subsequent contact hole filling processes, ultimately leading to high and unstable contact resistance. See also... Figure 1 ,in Figure 1 The diagram shows a contact hole 141 in wafer 1 and residues 142 within the contact hole, including polymers, oxides, etc.

[0003] Existing technologies typically employ a combination of dry and wet methods for cleaning contact hole 141 (see details). Figure 2 (A cleaning solution 10 is introduced into the contact hole 141). Due to the isotropic nature of wet cleaning, prolonged wet cleaning will alter the morphology of the contact hole 141 with a high aspect ratio structure (see details). Figure 3 Furthermore, because the contact hole has a high aspect ratio structure, some areas of residue inside the contact hole may not be completely cleaned (for example, residue at the bottom of the contact hole may not be cleaned), resulting in a certain amount of residue remaining inside the contact hole after cleaning, which affects the performance of the semiconductor device. Summary of the Invention

[0004] This invention provides a cleaning method and apparatus for contact holes. By using this cleaning method to clean contact holes, it can ensure that the residue inside the contact holes can be completely removed, and also ensure the morphology of the contact holes.

[0005] Firstly, a method for cleaning contact holes is provided, comprising:

[0006] Introduce a temperature-responsive reagent into the contact hole;

[0007] Temperature regulation converts the temperature-responsive reagent into a high-viscosity gel state, which adheres to the residue inside the contact pores;

[0008] Temperature is controlled to solidify temperature-responsive reagents in a gel state;

[0009] Remove the cured temperature-responsive reagent from the contact hole.

[0010] Optionally, temperature-responsive reagents include natural hydrogels and / or synthetic hydrogels.

[0011] Optionally, the natural hydrogel includes any one or both of hyaluronic acid hydrogel and gelatin hydrogel.

[0012] Optionally, the synthetic hydrogel includes any one or more of polyvinyl alcohol hydrogel, polymethyl methacrylate hydrogel, polyacrylamide hydrogel, and thermosensitive chitin hydrogel.

[0013] Optionally, the polyacrylamide hydrogel is prepared by using polyacrylamide, maleic acid and chitosan as raw materials to prepare an aqueous solution.

[0014] Optionally, the mass fractions of each component in the raw material of the polyacrylamide hydrogel are as follows:

[0015] The composition is 1%~20% polyacrylamide, 0.5%~1% maleic acid, 5%~10% chitosan, and the remainder is water.

[0016] Optionally, the steps for introducing a temperature-responsive reagent into the contact hole are as follows:

[0017] Add a temperature-responsive reagent to the opening of the contact hole;

[0018] The pressure is increased to the first pressure, causing the temperature-responsive reagent to flow into the contact hole.

[0019] Optionally, the first pressure ranges from 9 MPa to 11 MPa.

[0020] Optionally, the temperature is adjusted to a first temperature to transform the temperature-responsive reagent into a high-viscosity gel state; the temperature is then adjusted to a second temperature to transform the temperature-responsive reagent from a gel state into a solidified state; wherein the first temperature is lower than the second temperature.

[0021] Optionally, the first temperature ranges from 50 to 75°C.

[0022] Optionally, the second temperature ranges from 75 to 120°C.

[0023] Optionally, in the gel state, the adhesion force of the temperature-responsive reagent ranges from 5 N / cm to 10 N / cm.

[0024] Optionally, the steps for removing the cured temperature-responsive reagent are as follows:

[0025] After fixing the cured temperature-responsive reagent to the surface using a moving component, the cured temperature-responsive reagent is removed from the contact hole using the moving component.

[0026] Optionally, the moving component and the cured temperature-responsive reagent can be fixed by any one of bonding, adhesion, or adsorption.

[0027] In a second aspect, a method for cleaning a semiconductor device is provided, including a method for cleaning contact holes as described in any of the preceding claims.

[0028] Thirdly, a cleaning device for contact holes is provided, comprising:

[0029] A reagent delivery assembly for introducing temperature-responsive reagents into a contact orifice;

[0030] The temperature control component regulates the temperature to convert the temperature-responsive reagent into a high-viscosity gel state, adhering to the residue in the contact pores; and regulates the temperature to solidify the temperature-responsive reagent in the gel state.

[0031] A movable component is used to remove the cured temperature-responsive reagent from the contact hole.

[0032] The unexpected technical effects of the technical solution provided by this invention are:

[0033] This invention provides a method for cleaning contact holes. A temperature-responsive reagent is introduced into the contact hole, and the temperature is adjusted to transform it into a high-viscosity gel state. The high-viscosity gel state of the temperature-responsive reagent adsorbs residues within the contact hole. After solidification, the high-viscosity gel state of the temperature-responsive reagent is directly removed from the contact hole, thus cleaning the contact hole. Unexpected technical effects include: (1) Using a gel state of temperature-responsive reagent to clean contact holes effectively controls the solvent evaporation rate and solution flow, ensuring the temperature-responsive reagent is well retained within the contact hole. (2) The gel state of the temperature-responsive reagent has a porous structure, which can capture residues (such as oxides, organic matter, etc.) within the pores of the porous structure through adsorption. Furthermore, the gel state of the temperature-responsive reagent also possesses a soft mechanical wiping effect. Compared to traditional solvent cleaning, this soft mechanical wiping effect can better remove residues from the deepest parts of the contact hole (a hole with a high aspect ratio). (3) When cleaning contact holes with traditional solvents, the high aspect ratio of the contact holes leads to residual cleaning solution, which introduces new residues. However, when cleaning contact holes with gel-like temperature-responsive reagents, the reagents can be directly solidified, removing them from the contact holes without introducing new residues. (4) When cleaning contact holes with solvents, the high aspect ratio of the contact holes necessitates repeated cleaning, which is complex and time-consuming. The cleaning method provided by this invention eliminates the need for repeated cleaning. The cleaning steps are simpler, and the cleaning time is significantly shorter than traditional solution cleaning (due to the high efficiency of high-viscosity gels in adsorbing residues, while the efficiency of solution cleaning is low), which helps to further ensure the device fabrication efficiency. (5) By utilizing the temperature response characteristics of temperature-responsive reagents, the temperature-responsive reagents in gel state can be solidified by adjusting the temperature. After the temperature-responsive reagents in gel state completely adsorb the residues in the contact hole, the temperature-responsive reagents in gel state can be solidified, and the solid waste liquid and residues in the contact hole can be directly removed from the contact hole. This gel cleaning method can effectively avoid the technical problem of the contact hole morphology changing due to the excessive cleaning time when cleaning the contact hole with traditional solution. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 A schematic diagram of a wafer structure provided for related technologies;

[0036] Figure 2 Another schematic diagram of a wafer structure provided for related technologies;

[0037] Figure 3 Another schematic diagram of a wafer structure provided for related technologies;

[0038] Figure 4 A flowchart of a cleaning method for contact holes provided by the present invention;

[0039] Figure 5 This is a flowchart of a semiconductor device cleaning method according to the present invention;

[0040] Figure 6 A schematic diagram of the structure of a semiconductor device provided by the present invention;

[0041] Figure 7 A schematic diagram of another semiconductor device provided by the present invention;

[0042] Figure 8 A schematic diagram of the structure of a semiconductor device provided by the present invention;

[0043] Figure 9 This is a structural block diagram of a contact hole cleaning device provided by the present invention;

[0044] Figure 10 This is a structural block diagram of another contact hole cleaning device provided by the present invention;

[0045] Figure 11 This is a structural block diagram of another contact hole cleaning device provided by the present invention;

[0046] Figure 12 This is a structural block diagram of another contact hole cleaning device provided by the present invention.

[0047] The attached figures are labeled as follows:

[0048] 1: Wafer; 10: Cleaning solution; 11: Substrate; 111: PMOS region; 112: NMOS region; 113: Isolation structure; 114: First source; 115: First drain; 116: Second source; 117: Second drain; 12: Gate oxide layer; 13: Gate structure; 131: Gate; 132: Gate sidewall; 14: Intermetallic dielectric layer; 141: Contact hole; 142: Residue; 15: Temperature-responsive reagent; 16: Moving component;

[0049] 21: Sealed cavity; 22: Wafer carrier assembly; 221: First carrier; 222: Second carrier; 23: Reagent delivery assembly; 24: Drive assembly; 241: First drive unit; 242: First transmission component; 243: Second drive unit; 244: Second transmission component; 25: Pressure control assembly; 26: Temperature control assembly. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0051] Figure 4 A flowchart illustrating a cleaning method for contact holes provided by this invention. See also... Figure 4 ,include:

[0052] S101. Introduce a temperature-responsive reagent into the contact hole.

[0053] In one example provided by the present invention, step S101 includes:

[0054] Step 1: Drop a temperature-responsive reagent into the opening of the contact hole.

[0055] In one example, when a temperature-responsive reagent is dripped into the contact hole opening, the flow rate of the temperature-responsive reagent can be 1300 L / min to 1800 L / min, and the dripping time can be 280 s to 320 s.

[0056] For example, the flow rate of the temperature-responsive reagent is 1500 L / min, and the dropping time is 300 s.

[0057] In this embodiment, if the flow rate of the temperature-responsive reagent is too low, it will negatively impact the production efficiency of the process; if the flow rate is too high, it will hinder the reagent from effectively covering the opening of the contact hole or flowing into the contact hole. Using the aforementioned flow rate ensures both production efficiency and adequate coverage of the contact hole opening or flow into the contact hole.

[0058] In one example, the temperature-responsive reagent includes natural hydrogels and / or synthetic hydrogels.

[0059] Natural hydrogels refer to hydrogels formed from natural substances, while synthetic hydrogels refer to hydrogels synthesized artificially. Both the natural and synthetic hydrogels used in this invention need to possess temperature responsiveness, meaning they can change their form in response to temperature variations. For example, they can transform into a high-viscosity gel state or a solid state under temperature changes.

[0060] In one example, the natural hydrogel includes any one or both of hyaluronic acid hydrogel and gelatin hydrogel.

[0061] In one example, the synthetic hydrogel includes any one or more of polyvinyl alcohol hydrogel, polymethyl methacrylate hydrogel, polyacrylamide hydrogel, and thermosensitive chitin hydrogel.

[0062] In one example, the polyacrylamide hydrogel is obtained by preparing an aqueous solution using polyacrylamide, maleic acid, and chitosan as raw materials.

[0063] In one example, the mass fractions of each component in the raw material of the polyacrylamide hydrogel are as follows:

[0064] The composition is 1%~20% polyacrylamide, 0.5%~1% maleic acid, 5%~10% chitosan, and the remainder is water.

[0065] For example, the composition is 15% polyacrylamide, 0.75% maleic acid, 7.5% chitosan, and the remainder is water.

[0066] In this embodiment, polyacrylamide and maleic acid are reacted to form a long-chain structure. This long-chain structure can form large molecular clusters, which can aggregate to form a gel with micropores. This micropore adsorption effect removes residues from the contact pores. Chitosan is used to provide adhesion. If the ratio of polyacrylamide to maleic acid is too high or too low, gelation will not occur. If the ratio of chitosan is too high, the adhesion will be too strong, making it difficult to enter the contact pores and affecting the subsequent solidification of the temperature-responsive reagent from a high-viscosity gel state. If the ratio of chitosan is too low, the adhesion will be reduced, making it difficult to adhere residues from the contact pores.

[0067] The second step is to increase the pressure to the first pressure, allowing the temperature-responsive reagent to flow into the contact hole.

[0068] For example, the first pressure ranges from 9 MPa to 11 MPa, and the pressure is maintained for 8 to 15 seconds.

[0069] For example, the first pressure ranges from 10 MPa, and the pressure is maintained for 10 seconds.

[0070] In this embodiment, a temperature-responsive reagent is first dropped into the contact hole opening, and then the pressure is increased to a first pressure. The pressure difference forces the temperature-responsive reagent into the contact hole, preventing it from remaining at the opening due to liquid surface tension and failing to enter the hole. Using a first pressure within the aforementioned range ensures a sufficiently large pressure difference to fill the contact hole, thereby ensuring that the temperature-responsive reagent, in its high-viscosity gel state, can better adsorb residues within the contact hole.

[0071] S102. Temperature regulation converts the temperature-responsive reagent into a high-viscosity gel state, which adheres to the residue in the contact pores.

[0072] In one example, if the temperature-responsive reagent is a polyacrylamide hydrogel, step S102 includes:

[0073] A first temperature is used to transform the temperature-responsive reagent into a high-viscosity gel state. The first temperature ranges from 50℃ to 75℃.

[0074] In this embodiment, if the first temperature is too low, the temperature-responsive reagent will fail to gel; if the first temperature is too high, the temperature-responsive reagent will solidify directly, resulting in a lack of adhesion and inability to adhere to residues within the contact holes. Using a first temperature within the aforementioned range ensures that the temperature-responsive reagent can transform into a high-viscosity gel state.

[0075] In this embodiment, the adhesion force of the high-viscosity gel-state temperature-responsive reagent ranges from 5 N / cm to 10 N / cm.

[0076] For example, the adhesion force of the gel-state temperature-responsive reagent is 8 N / cm.

[0077] In this embodiment, if the adhesion of the high-viscosity gel-state temperature-responsive reagent is too low, it will fail to completely adsorb the residue within the contact holes. Conversely, if the adhesion of the high-viscosity gel-state temperature-responsive reagent is too high, it can easily lead to inverted bonding, meaning that the metal pillars on the semiconductor device surface may connect to each other under the adhesive force of the temperature-responsive reagent, which is detrimental to the performance of the semiconductor device. By using a temperature-responsive reagent within the aforementioned adhesion range, it is ensured that the adhesion of the temperature-responsive reagent remains at a moderate level, ensuring the removal of residues within the contact holes and preventing any impact on the metal pillars of the semiconductor device.

[0078] Of course, those skilled in the art should understand that by using temperature-responsive reagents for different hydrogels, the corresponding first temperature, second temperature (or third temperature, fourth temperature, fifth temperature, etc.) can be set according to the temperature response characteristics of the hydrogel used, so that other hydrogels can be converted from liquid to high-viscosity gel state and solidified from high-viscosity gel state. It is only necessary to satisfy that the hydrogel completely fills the contact pores, efficiently adsorbs residues, and can solidify so that the residues are taken out when it is removed.

[0079] S103. Adjust the temperature to solidify the temperature-responsive reagent in the gel state.

[0080] In one example, if the temperature-responsive reagent is a polyacrylamide hydrogel, step S103 includes:

[0081] The temperature is adjusted to a second temperature, causing the temperature-responsive reagent to change from a gel state to a solid state; wherein the first temperature is lower than the second temperature. The second temperature is typically between 75 and 120°C. For example, the second temperature could be 80°C.

[0082] In this embodiment, if the second temperature is too high, the temperature-responsive reagent will solidify rapidly, which is detrimental to the adsorption of residues in the contact pores. Conversely, if the second temperature is too low, the curing efficiency of the temperature-responsive reagent will be compromised. By using a second temperature within the aforementioned range, both curing efficiency and the adhesion effect of the temperature-responsive reagent can be ensured.

[0083] S104. Remove the cured temperature-responsive reagent from the contact hole.

[0084] In one example, step S104 includes:

[0085] After fixing the cured temperature-responsive reagent to the surface using a moving component, the cured temperature-responsive reagent is removed from the contact hole by moving the moving component.

[0086] In one example, the fixation method between the moving component and the cured temperature-responsive reagent includes bonding, adhesion, and adsorption. Adhesion can involve bonding the moving component to the cured temperature-responsive reagent using an adhesive or other material with strong adhesion. Adsorption can be vacuum adsorption.

[0087] In this embodiment, a moving component is used to fix the cured temperature-responsive reagent. Then, by moving the moving component, the cured temperature-responsive reagent is directly removed from the contact hole to remove any residue. The moving component and the cured temperature-responsive reagent can be fixed using bonding, adhesive, or adsorption methods to ensure effective fixation.

[0088] In one example, when a moving component is bonded to a cured temperature-responsive reagent, the bonding process parameters are as follows:

[0089] Using a temperature of 45℃~55℃, the moving component is pressed onto the surface of the temperature-responsive reagent, allowing the moving component to bond with the temperature-responsive reagent.

[0090] For example, a temperature of 50°C is used to press the moving component onto the surface of a temperature-responsive reagent, allowing the moving component to bond with the temperature-responsive reagent.

[0091] In this embodiment, the moving component can be a polyacrylamide mold, thereby further ensuring the bonding effect between the moving component and the temperature-responsive reagent.

[0092] Figure 5 A flowchart illustrating a semiconductor device cleaning method provided by this invention. See also... Figure 5 ,include:

[0093] S201. A wafer is provided, on which a plurality of contact holes are formed.

[0094] In the fabrication of semiconductor devices, multiple semiconductor devices are typically formed on a single wafer.

[0095] In one example, the semiconductor device can be any of the following: a complementary metal-oxide-semiconductor (CMOS) device, a P-type metal-oxide-semiconductor (NMOS) PMOS device, an N-type metal-oxide-semiconductor (NMOS) device, etc.

[0096] Of course, the contact hole cleaning method provided by this invention can be applied to any device that includes contact holes.

[0097] Figure 6 This is a schematic diagram of the structure of a semiconductor device provided by the present invention. See also... Figure 6 , Figure 6 The diagram shows the structure of a CMOS device.

[0098] In this embodiment, the CMOS device includes:

[0099] A substrate 11 is provided with a PMOS region 111 and an NMOS region 112, which are separated by an isolation structure 113. A source and a drain are formed in the PMOS region 111 and the NMOS region 112, wherein the source in the PMOS region is a first source 114, the drain in the PMOS region is a first drain 115, the source in the NMOS region is a second source 116, and the drain in the NMOS region is a second drain 117.

[0100] A gate oxide layer 12 and a gate structure 13 are sequentially formed on the PMOS region 111 and the NMOS region 112. The gate structure includes a gate 131 and a gate sidewall 132.

[0101] An intermetallic dielectric layer 14 is formed on the gate structure 13, the isolation structure 113, the first source 114, the first drain 115, the second source 116, and the second drain 117. A contact hole 141 is formed in the intermetallic dielectric layer 14, and the contact hole 141 is connected to the gate 131, the first source 114, the second source 116, the first drain 115, and the second drain 117, respectively. The contact hole 141 contains a residue 142.

[0102] S202. Introduce a temperature-responsive reagent into the contact hole.

[0103] Please refer to step S101.

[0104] Figure 7 A schematic diagram of another semiconductor device provided by the present invention. See also... Figure 7 A temperature-responsive reagent 15 is introduced into the contact hole 141 and onto the surface of the intermetallic dielectric layer 14.

[0105] S203, temperature regulation converts the temperature-responsive reagent into a high-viscosity gel state, adhering to the residue in the contact pores.

[0106] Please refer to step S102.

[0107] S204. Adjust the temperature to solidify the temperature-responsive reagent in the gel state.

[0108] Please refer to step S103.

[0109] S205. Remove the cured temperature-responsive reagent from the contact hole.

[0110] Please refer to step S104.

[0111] Figure 8 A schematic diagram of another semiconductor device provided by the present invention. See also... Figure 8The moving component 16 is fixed to the cured temperature-responsive reagent 15, and the fixing method can be bonding.

[0112] Please see Figures 9 to 12 The present invention also provides a cleaning apparatus for contact holes, the cleaning apparatus for contact holes comprising:

[0113] The reagent delivery assembly 23 is used to introduce a temperature-responsive reagent into the contact hole;

[0114] Temperature control component 26 regulates the temperature to convert the temperature-responsive reagent into a high-viscosity gel state, causing the gel-state temperature-responsive reagent to adhere to the residue in the contact hole; and regulates the temperature to solidify the gel-state temperature-responsive reagent.

[0115] Moving component 16 is used to remove the cured temperature-responsive reagent.

[0116] In this embodiment, a cleaning apparatus for contact holes is provided. A temperature-responsive reagent is delivered into the contact hole via a reagent delivery component. A temperature control component controls the temperature-responsive reagent to convert into a high-viscosity gel state and then into a solidified state. Finally, a solid removal component removes the solidified temperature-responsive reagent, thereby ensuring complete removal of residues from the contact hole. Simultaneously, the morphology of the contact hole is also preserved.

[0117] In this embodiment, the reagent delivery assembly 23 can be a dropper.

[0118] In this embodiment, the cleaning device for the contact hole further includes:

[0119] Sealed cavity 21;

[0120] The wafer carrier assembly 22 includes a first carrier 221 and a second carrier 222, wherein the second carrier 222 is used to support the first carrier 221 and the first carrier 221 is used to support the wafer.

[0121] The driving assembly 24 includes a first driving unit 241, a first transmission member 242, a second driving unit 243, and a second transmission member 244. The first driving unit 241 drives the first transmission member 242 to rotate, thereby controlling the rotation of the reagent delivery assembly 23 (the reagent delivery assembly 23 is fixed together with the moving assembly 16; by controlling the rotation of the reagent delivery assembly 23, one of the reagent delivery assembly 23 or the moving assembly 16 can be controlled to face the surface of the wafer 1). The second driving unit 243 drives the second transmission member 244 to move up and down. By moving up and down the second transmission member 244, the distance between the reagent delivery assembly 23, the moving assembly 16, and the wafer can be controlled. After the moving assembly 16 is fixed with the cured temperature-responsive reagent, the cured temperature-responsive reagent can be removed from the contact hole by moving up and down the second transmission member 244.

[0122] The pressure control component 25 is used to control the pressure in the sealing cavity 21. By controlling the pressure, the temperature-responsive reagent at the opening of the contact hole is forced into the contact hole by the pressure difference.

[0123] In this embodiment, the first driving unit 241 can be a drive motor, which controls the rotation of the first transmission component 242 to drive the reagent delivery assembly to rotate.

[0124] In this embodiment, the second drive unit 243 can be a linear motor, which controls the second transmission component 244 to move up and down, thereby controlling the moving component 16 to move closer to or away from the wafer 1.

[0125] The contact hole cleaning device provided in this embodiment is used as follows:

[0126] First step, such as Figure 9 As shown, the reagent delivery assembly 23 is oriented toward the surface of wafer 1, and a temperature-responsive reagent is delivered to the surface of wafer 1 through the reagent delivery assembly 23.

[0127] The second step, as Figure 10 As shown, the pressure inside the sealed cavity 21 is increased by the pressure control component 25 to ensure that the temperature-responsive reagent can completely enter the contact hole on the wafer 1.

[0128] The third step, as Figure 10 As shown, the temperature inside the sealed cavity 21 is increased by the temperature control component 26, causing the temperature-responsive reagent to transform into a high-viscosity gel state.

[0129] Step four, as Figure 10 As shown, the temperature inside the sealed cavity is increased by the temperature control component 26, causing the temperature-responsive reagent to change into a solidified state.

[0130] Step 5, as Figure 11As shown, the reagent delivery assembly 23 is driven to rotate 180 degrees by the first driving unit 241 and the first transmission component 242 in the driving assembly 24, so that the moving assembly 16 faces the wafer surface and the moving assembly 16 is brought into contact with the temperature-responsive reagent on the surface of the wafer 1 and fixed. Alternatively, after the temperature-responsive reagent has been initially cured, the moving assembly 16 is rotated to make surface contact with the temperature-responsive reagent and then synchronously cured and bonded.

[0131] Step 6, as follows Figure 12 As shown, the moving component 16 is driven away from the wafer 1 by the second driving unit 243 and the second transmission member 244 in the driving component 24, thereby removing the cured temperature-responsive reagent from the contact hole by the moving component 16.

[0132] Finally, it should be noted that the unexpected technical effects of the technical solution provided in this application include:

[0133] This invention provides a method for cleaning contact holes. A temperature-responsive reagent is introduced into the contact hole, and the temperature is adjusted to transform it into a high-viscosity gel state. The high-viscosity gel state of the temperature-responsive reagent adsorbs residues within the contact hole. The high-viscosity gel state of the temperature-responsive reagent is then solidified and directly removed from the contact hole, thereby cleaning the contact hole. Unexpected technical effects include: (1) Using a gel state of temperature-responsive reagent to clean contact holes effectively controls the solvent evaporation rate and solution flow, ensuring the temperature-responsive reagent is well retained within the contact hole. (2) The gel state of the temperature-responsive reagent has a porous structure, which can capture residues (such as oxides, organic matter, etc.) within the pores of the porous structure. Furthermore, the gel state of the temperature-responsive reagent also possesses a soft mechanical wiping effect. Compared to traditional solvent cleaning, this soft mechanical wiping effect can better remove residues from the deepest parts of the contact hole (a hole with a high aspect ratio). (3) When cleaning contact holes with traditional solvents, the high aspect ratio of the contact holes leads to residual cleaning solution, which introduces new residues. However, when cleaning contact holes with gel-like temperature-responsive reagents, the reagents can be directly solidified, removing them from the contact holes without introducing new residues. (4) When cleaning contact holes with solvents, the high aspect ratio of the contact holes necessitates repeated cleaning, which is complex and time-consuming. The cleaning method provided by this invention eliminates the need for repeated cleaning. The cleaning steps are simpler, and the cleaning time is significantly shorter than traditional solution cleaning (due to the high efficiency of high-viscosity gels in adsorbing residues, while the efficiency of solution cleaning is low), which helps to further ensure the device fabrication efficiency. (5) By utilizing the temperature response characteristics of temperature-responsive reagents, the temperature-responsive reagents in gel state can be solidified by adjusting the temperature. After the temperature-responsive reagents in gel state completely adsorb the residues in the contact hole, the temperature-responsive reagents in gel state can be solidified, and the solid waste liquid and residues in the contact hole can be directly removed from the contact hole. This gel cleaning method can effectively avoid the technical problem of the contact hole morphology changing due to the excessive cleaning time when cleaning the contact hole with traditional solution.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for cleaning contact holes, characterized in that, include: Introduce a temperature-responsive reagent into the contact hole; Temperature regulation converts the temperature-responsive reagent into a high-viscosity gel state, which adheres to the residue inside the contact pores; Temperature is controlled to solidify temperature-responsive reagents in a gel state; Remove the cured temperature-responsive reagent from the contact hole.

2. The cleaning method for contact holes according to claim 1, characterized in that, Temperature-responsive reagents include natural hydrogels and / or synthetic hydrogels.

3. The cleaning method for contact holes according to claim 2, characterized in that, The natural hydrogel includes any one or both of hyaluronic acid hydrogel and gelatin hydrogel.

4. The cleaning method for contact holes according to claim 2, characterized in that, The synthetic hydrogel includes any one or more of polyvinyl alcohol hydrogel, polymethyl methacrylate hydrogel, polyacrylamide hydrogel, and thermosensitive chitin hydrogel.

5. The cleaning method for contact holes according to claim 4, characterized in that, The polyacrylamide hydrogel is prepared by using polyacrylamide, maleic acid and chitosan as raw materials and preparing an aqueous solution.

6. The cleaning method for contact holes according to claim 5, characterized in that, The mass fractions of each component in the raw material of the polyacrylamide hydrogel are as follows: The composition is 1%~20% polyacrylamide, 0.5%~1% maleic acid, 5%~10% chitosan, and the remainder is water.

7. The method for cleaning contact holes according to any one of claims 1 to 6, characterized in that, The steps for introducing a temperature-responsive reagent into the contact hole are as follows: Add a temperature-responsive reagent to the opening of the contact hole; The pressure is increased to the first pressure, causing the temperature-responsive reagent to flow into the contact hole.

8. The cleaning method for contact holes according to claim 7, characterized in that, The first pressure ranges from 9 MPa to 11 MPa.

9. The method for cleaning contact holes according to any one of claims 1 to 6, characterized in that, The temperature is adjusted to a first temperature to transform the temperature-responsive reagent into a high-viscosity gel state; the temperature is then adjusted to a second temperature to transform the temperature-responsive reagent from a gel state into a solidified state; wherein the first temperature is lower than the second temperature.

10. A cleaning device for contact holes, characterized in that, include: A reagent delivery assembly for introducing temperature-responsive reagents into a contact orifice; Temperature control components are used to regulate the temperature so that the temperature-responsive reagent is converted into a high-viscosity gel state, and the temperature-responsive reagent in the gel state adheres to the residue in the contact hole; It is also used to regulate temperature and solidify temperature-responsive reagents in a gel state; A movable component is used to remove the cured temperature-responsive reagent from the contact hole.

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