Water-based high-efficiency chemical reagent for removing particles from substrate surfaces

Abstract

Embodiments of this disclosure include systems and methods for cleaning semiconductor substrates. The method includes: rotating a substrate mounted on a substrate support; spraying a cleaning agent containing one or more chelating agents onto the front side of the substrate using a front nozzle assembly positioned above the substrate support; and spraying the cleaning agent onto the back side of the substrate using a back dispenser assembly positioned below the substrate support.

Description

Background Technology

[0001] field

[0002] The embodiments of this disclosure generally relate to semiconductor substrate processing, and more specifically to semiconductor substrate processing tools and methods thereof.

[0003] Related technical descriptions

[0004] In semiconductor manufacturing processes, including Chemical Mechanical Polishing (CMP), dicing, bonding, and lithography, the thorough removal of unwanted particles from the substrate surface is essential after each step of semiconductor manufacturing. For example, dicing processes, which use substrate dicing techniques such as diamond blades, lasers, or plasma to cut each die into individual chips, may generate unwanted particles and debris on the substrate surface.

[0005] Inadequately cleaned substrate surfaces directly jeopardize the success of subsequent chip-to-substrate bonding in semiconductor manufacturing. Contaminants and residual particles act as physical barriers, hindering proper bonding contact and resulting in weak bonds. These weak bonds lead to reduced structural integrity, where the bonded structure becomes susceptible to mechanical stress, thermal cycling, and vibration, increasing the risk of device failure or performance degradation. Furthermore, conductive contaminants, such as ionic impurities, create pathways for leakage current between bonded substrates, compromising signal integrity, increasing power consumption, and potentially damaging sensitive circuitry. Additionally, the presence of contaminants can induce the formation of defects such as misalignment, cracking, and pinholes, acting as potential failure sites and significantly impacting yield and reliability.

[0006] Therefore, there is a need for a method and apparatus that can clean substrates at various processing stages, and that is efficient and can effectively remove a wide range of contaminant particles. Summary of the Invention

[0007] The embodiments described herein generally relate to systems and methods for processing semiconductor substrates, and more particularly, to systems and methods for cleaning semiconductor substrates after a chemical mechanical polishing (CMP) process.

[0008] In one embodiment, a method for cleaning a substrate is provided. The method includes rotating a substrate disposed on a substrate support, spraying a cleaning agent onto the front side of the substrate using a front nozzle assembly, and spraying the cleaning agent onto the back side of the substrate using a back dispenser assembly. The cleaning agent comprises one or more chelating agents.

[0009] In another embodiment, a method for cleaning a substrate is provided. The method includes rotating a substrate support and spraying a cleaning agent containing one or more chelating agents from above the substrate onto the front side of the substrate using a front nozzle assembly.

[0010] In yet another embodiment, a method for cleaning a substrate is provided. The method includes rotating a substrate disposed on a substrate support, spraying a front side of the substrate using a cleaning agent comprising one or more chelating agents through a front nozzle assembly disposed above the substrate support, and spraying a back side of the substrate using the cleaning agent through a back dispenser assembly disposed below the substrate support. Attached Figure Description

[0011] To gain a more detailed understanding of the features described above in this disclosure, a more specific description of the disclosure, which has been briefly outlined above, can be obtained with reference to the embodiments illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only exemplary embodiments of this disclosure and should therefore not be construed as limiting the scope of this disclosure, and other equally effective embodiments are permitted.

[0012] Figure 1 This is a cross-sectional schematic diagram of a substrate processing apparatus according to an embodiment, the substrate processing apparatus including a substrate support, a back plate and a dispensing assembly.

[0013] Figure 2 This is a schematic cross-sectional view of a substrate processing apparatus having multiple holes on a back plate according to an embodiment.

[0014] Figure 3 This is a process flow diagram of a method for processing a substrate according to an embodiment.

[0015] To facilitate understanding, the same element symbols have been used to denote common elements across the figures, where possible. It is contemplated that elements and features of one embodiment may be advantageously incorporated into other embodiments without further description. Detailed Implementation

[0016] The embodiments described herein generally relate to semiconductor substrate processing, and more particularly to systems and methods for cleaning semiconductor substrates after a chemical mechanical polishing (CMP) process.

[0017] Integrated circuits are typically formed on a substrate by sequentially depositing conductive, semiconductor, or insulating layers. Semiconductor manufacturing involves numerous processes, in which the substrate surface is cleaned at various stages before device formation is complete. Removing particles from the substrate surface after chemical mechanical polishing (CMP) treatment presents challenges, particularly due to the diverse range of contaminant particles found on the CMP-polished substrate surface. A common method for cleaning substrates involves deionized (DI) water cleaning, such as rinsing the substrate with DI water at various temperatures to remove contaminant particles remaining on the substrate surface. Conventional methods like DI water cleaning exhibit limited effectiveness, resulting in low particle removal rates, such as around 50%. These methods often struggle with a wide range of particles, including both dielectric and metallic particles, as well as residual materials, leading to unsatisfactory cleaning results. Furthermore, the process can unintentionally affect delicate substrate structures. To ensure reliable chip-to-substrate adhesion, more efficient and adaptive solutions for particle removal are needed.

[0018] This disclosure provides a chemical solution to address the challenge of particle removal from substrate surfaces. By combining an effective solvent and chelating agent, the method effectively removes both dielectric and metallic particles, as well as residual materials. Formulated with DI water at a specific ratio, the method achieves a particle removal rate of 98% or higher, thus surpassing the limitations of conventional DI water cleaning methods.

[0019] Figure 1 A schematic cross-sectional view of a substrate processing apparatus 100 is shown, which includes a substrate support 104 and a back plate 105. As further described herein, the substrate support 104 is rotatable. The back plate 105 can be moved vertically or fixed.

[0020] A front nozzle assembly 112 is mounted on a substrate support 104 and configured to be mounted on a substrate 102, which is mounted on the substrate support 104 (e.g., off-center relative to the center of the substrate). The front nozzle assembly 112 is capable of spraying cleaning agent onto the front side 102a of the substrate 102 in the form of a jet 114. In some embodiments, the front nozzle assembly 112 releases cleaning agent to rinse the front side 102a of the substrate 102. In operation, the substrate 102 rotates at about 10 rpm to about 1000 rpm, such as about 500 rpm to about 900 rpm. The front nozzle assembly 112 is capable of moving along a planar axis above the substrate 102 in a direction between the center of the substrate and the edge of the substrate 102. The front nozzle assembly 112 is capable of dispensing cleaning agent at a rinsing flow rate of about 800 ml / min to about 3000 ml / min for mega-sonic cleaning and at a rinsing flow rate of about 30 ml / min to about 40 ml / min for droplet jet cleaning.

[0021] In some embodiments, the cleaning agent from the cleaning source is a solution of an organic solvent, a chelating agent, a non-oxidizing acid, a surfactant, and water. The cleaning agent may include one or more chelating agents, such as benzotriazole, toluenetriazole, 5-phenyl-benzotriazole, 5-nitro-benzotriazole, 3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole, hydroxybenzotriazole, 2-(5-amino-pentyl)-benzotriazole, 1-amino-1,2,3-triazole, 1-amino-5-methyl-1,2,3-triazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, etc. 3-Isopropyl-1,2,4-triazole, 5-phenylthio-benzotriazole, halobenzotriazole, naphthiatriazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 4-methyl-2-phenylimidazolium, 2-mercaptothiazoline, 5-aminotetrazole, 5-amino-1,3,4-thiadiazole-2-thiol, 2,4-diamino-6-methyl-1,3,5-triazine, thiazole, triazine, methyltetrazole, 1,3-dimethyl- 2-Imidazolidinone, 1,5-pentamethylenetetrazol, 1-phenyl-5-mercaptotetrazol, diaminomethyltriazine, mercaptobenzothiazole, imidazolinethion, mercaptobenzimidazole, 4-methyl-4H-1,2,4-triazol-3-thiol, 5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, tricresylphosphonate, indole, guanine, adenine, glycerol, thioglycerol, triacetic acid, salicylamide, iminodiacetic acid, benzoguanidine, melamine Amines, thiocyanuric acid, anthraquinone acids, tartaric acid, gallic acid, ascorbic acid, salicylic acid, 8-hydroxyquinoline, 5-carboxylic acid-benzotriazole, 3-mercaptopropanol, boric acid, iminodiacetic acid, phenols, carboxylic acids, phosphonic acids, thiocarbamates, ethylenediaminetetraacetic acid, N,N'-bis(2-hydroxyphenyl)ethylenediiminodiacetic acid, 1-hydroxyethane, 1,1-diphosphonic acid, triethylenetetraminehexaacetic acid, Mannich bases, iminodiacetic acid and their derivatives or salts, or combinations thereof. In one embodiment, a water-soluble chelating agent with the ability to adhere to fresh copper surfaces and / or copper oxide films is used. This adhesion ability allows these chelating agents to passivate or effectively protect copper-containing layers.

[0022] During the manufacturing process, the deposition of metal ions can affect the substrate surface, thereby altering the properties of the components. When these metals are exposed to a chelating agent, they bond with the chelating agent with a specific affinity, and these metals are then pulled away from the substrate surface and removed from the cleaning solution.

[0023] Chelating agents are not limited to removing a single type of metal ion, but can bind to a wide range of metals, such as transition metals and trace elements frequently encountered in substrate processing. The use of chelating agents in cleaning agents enables thorough cleaning across a broad spectral coverage.

[0024] Furthermore, unlike more aggressive cleaning methods, chelation is effective and does not damage the brittle structures on the substrate surface. Due to the targeted binding nature of chelation, the risk of etching or unwanted reactions is reduced. Chelating agents can further include specific functional groups to enhance binding with specific metal ions, thereby providing high selectivity and reducing the possibility of accidental removal of desired elements.

[0025] Cleaning agents also include water-soluble organic solvents such as dimethyl sulfoxide (DMSO), dimethylacetamide (DMAc), n-methyl-2-pyrrolidone (NMP), diethylene glycol butyl ether, or combinations thereof. The inclusion of organic solvents is for the efficient breakdown and dissolution of misaligned organic particles, such as carbon. Depending on the specific solvent and chelating agent used, organic solvents enhance the chelating effect. Organic solvents have the ability to dissolve both the chelating agent and the metal ions, often exceeding the solubility achieved in water. This increased solubility brings the chelating agent and metal ions closer together, thereby promoting more frequent collisions and increasing the chelation reaction rate.

[0026] Furthermore, different organic solvents exhibit varying polarities and affinities for specific functional groups, thus providing a means to precisely control the selectivity of the chelation process. This promotes the misalignment between specific metal ions and chelating agents.

[0027] In aqueous solutions, metal ions are often surrounded by water molecules to form hydrated spheres. Certain organic solvents, characterized by a lower dielectric constant than water, are less effective at stabilizing these hydrated spheres, thus allowing for the substitution by chelating agents and subsequent formation of complexes with the metal ions. Furthermore, organic solvents can interact with the functional groups of chelating agents, thereby affecting their charge and polarity. This interaction can potentially modify the strength and selectivity of the metal-coordinate bond, thereby enhancing the stability of the resulting complexes.

[0028] Furthermore, specific organic solvents can interact with metal ions or chelating agents, thereby further facilitating the formation of complexes. These interactions may include hydrogen bonding, π-π interactions, or direct coordination with the metal center, contributing to the overall efficiency of the chelation process. A variety of non-oxidizing acids—HF, HCl, H₂SO₄, HBF₄, H₃PO₄, acetic acid, glycolic acid, and citric acid—were employed. These solutions were pH buffered using standard buffers such as citric acid, acetic acid, various amines (primary, secondary, and tertiary), triethylammonium hydroxide, tetramethylammonium hydroxide, choline, tricholine, and their associated salts to maintain the desired pH level. Typically, the pH of these cleaning solutions ranges from 1 to 12.

[0029] Cleaning agents can include organic bases, such as ethanolamine. Including organic bases in cleaning agents can influence chelation. By increasing the pH of the solution, organic bases can potentially deprotonate specific functional groups on the chelating agent. This deprotonation enhances the negative charge on these groups, thereby increasing their attraction to positively charged metal ions and strengthening the metal-coordinate bond. Organic bases can also dissolve both the chelating agent and the metal ion, thus increasing the likelihood of their interaction and promoting chelation. Some organic bases, similar to organic solvents, have low dielectric constants, which weaken the interaction between the metal ion and its hydrated sphere. This weakened interaction makes it easier for the metal ion to form a complex with the chelating agent. In some cases, the organic base itself can form a complex with the metal ion. These mixed complexes can then interact with the chelating agent to form ternary complexes characterized by enhanced stability and selectivity.

[0030] In one embodiment disclosed herein, the liquid treatment is characterized by the incorporation of an organic base compound, designed to enhance inhibitor removal and reduce process defects. Specifically, these compounds, including quaternary ammonium salts, alkanolamines, alkyl hydroxylamines, and their corresponding salts, exhibit basic properties within an organic structure.

[0031] To improve inhibitor removal and reduce defects, quaternary ammonium salts and alkanolamines can be used. It is important to note that quaternary ammonium salts also have the dual function of adjusting pH levels. Examples of organic basic compounds include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, ethyltrimethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, methyltri(hydroxyethyl)ammonium hydroxide, tetra(hydroxyethyl)ammonium hydroxide, benzyltrimethylammonium hydroxide, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, butyltrimethylammonium hydroxide, trimethylcyclohexylammonium hydroxide, tributylcyclohexylammonium hydroxide, monohydroxyethyltrimethylammonium hydroxide, dihydroxyethyldimethylammonium hydroxide (dimethylbis(2-hydroxyethyl)ammonium hydroxide), trihydroxyethylmonomethylammonium hydroxide, monohydroxyethyltriethylammonium hydroxide, ammonium acetate, dihydroxyethyldiethylammonium hydroxide, and trihydroxyethylmonoethyl hydroxide. Ammonium hydroxide, monohydroxypropyltrimethylammonium hydroxide, dihydroxypropyldimethylammonium hydroxide, trihydroxypropylmonomethylammonium hydroxide, ethyltrimethylammonium hydroxide, trimethyladamantylammonium hydroxide, tetramethylpiperidinium, tributylmethylammonium chloride, tetrabutylammonium bromide, tetraethylammonium bromide, tetraethylammonium chloride, 2-dimethylaminoethanol, 2-(methylamino)ethanol, ethanolamine, amino-2-propanol, triethylamine, tetramethylammonium chloride, monohydroxypropyltriethylammonium hydroxide, dihydroxypropyldiethylammonium hydroxide, choline hydroxydimethylbis(2-hydroxyethyl)ammonium hydroxide, ethyltrimethylammonium hydroxide, monoethanolamine, 2-amino-2-ethoxyethanol. Examples include ammonium hydroxide, trihydroxypropylmonoethylammonium hydroxide, and choline (e.g., choline hydroxide). Quaternary ammonium salts can be used alone or in combination of two or more.

[0032] Cleaning agents can also be dissolved in solvents such as water. As a solvent in cleaning agents, water activates one or more chelating agents in inorganic ions (particularly metal particles or metal ions), causing them to detach from the substrate surface. Water dissolves both the chelating agent and the metal ions, thereby enhancing their interaction and the likelihood of forming a complex. In cases of insufficient solubility, the reaction rate between the chelating agent and the metal ion is significantly slowed. Water molecules can form hydrated spheres around the metal ion, and these spheres may be replaced by the ligands of the chelating agent, allowing direct binding to the metal ion. In some cases, the hydrated spheres weaken the attraction between the metal ion and its surrounding anions, thus promoting competition for the chelating agent and subsequent complex formation. Furthermore, the interaction between water and the functional groups of the chelating agent can alter its charge and polarity, thereby affecting the strength and selectivity of the metal-coordinate bond. For example, water can protonate certain ligands, giving them a greater positive charge and potentially increasing their affinity for specific metal ions. It is worth noting that some chelating agents require a proton transfer reaction to form a stable complex with metal ions, and water plays a key role in this process as a proton donor or acceptor, thereby activating the chelating agent.

[0033] Surfactants act physically and are preferred for effectively peeling and removing impurities bonded to the substrate surface. The specific amount of surfactant is not strictly limited, but to enhance the peelability of the deposit, a range of about 0.0001% by mass to about 10% by mass for each agent is preferred, such as about 0.001% by mass to about 1% by mass.

[0034] While there are no strict limitations on the choice of surfactant, various categories are described, such as cationic, anionic, amphoteric, or nonionic surfactants. It is noteworthy that nonionic or anionic surfactants can be used because of their exceptional adhesion-peel properties and ability to prevent removed impurities from re-adhering to the substrate surface.

[0035] Cationic surfactants include quaternary ammonium salts, alkylamine salts, benzylalkylammonium salts, alkylpyridinium salts, imidazolium salts, and similar compounds.

[0036] Anionic surfactants include sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium alkyl diphenyl ether disulfonate, sodium alkyl naphthalene sulfonate, and other surfactants.

[0037] It also outlines amphoteric surfactants such as carboxybetaine, sulfobetaine, aminocarboxylate, and imidazoline derivatives.

[0038] Nonionic surfactants cover a wide range, including polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and compounds with oxyethylene or oxypropylene structures.

[0039] Polyoxyalkylene nonionic surfactants, particularly those with ethylene or propylene as their alkylene components, exhibit exceptional adhesive-peel properties. Specific examples include polyoxyalkylene alkyl ethers, polyoxyalkylene alkylbenzene ethers, polyoxyalkylene glycerol fatty acid esters, polyoxyalkylene fatty acid esters, polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene fatty acid monoalkanolamides, and polyoxyalkylene fatty acid dialkanolamides.

[0040] Still referencing Figure 1A back-side dispenser assembly 126 is positioned below the substrate 102 (e.g., centered below the substrate) and is capable of spraying cleaning agent onto the back side 102b of the substrate 102. The cleaning agent is sprayed through a channel 125 of the back-side dispenser assembly 126, which extends through a central portion of the back panel 105. In some embodiments, the back-side dispenser assembly 126 releases cleaning agent to rinse the back side 102b of the substrate 102. In operation, as the substrate 102 rotates, the cleaning agent fluid from the back-side dispenser assembly 126 is directed to the center of the back side 102b of the substrate 102. In some embodiments that can be combined with other embodiments described herein, the cleaning agent is dispensed from the back-side dispenser assembly 126 through a single central orifice.

[0041] Depending on the application, one or more piezoelectric transducers 128 may be embedded in the backplate 105 to form a megasonic plate. The megasonic plate is capable of applying megasonic energy to the fluid supplied by the back-side distributor assembly 126. In operation, the megasonic energy is coupled from the back side 102b of the substrate 102 to the front side 102a for agitation. The megasonic plate provides agitation, which, in combination with the cleaning processes described herein, dissociates residues and contaminants from the substrate 102. In some embodiments that can be combined with other embodiments described herein, megasonic energy is applied to the fluid between the backplate 105 and the back side 102b of the substrate 102 after the fluid has left the back-side distributor assembly 126, such as... Figure 1 As shown.

[0042] Figure 2 This is a schematic cross-sectional view of a substrate processing apparatus 200 having a back-side distributor assembly 226, on which a plurality of apertures 202 are provided on a backplate 205 of the substrate processing apparatus. In operation, fluid is ejected through channels 125 of the back-side distributor assembly 226 and guided through the plurality of apertures 202 on the backplate 205 to the back side 102b of the substrate 102. One or more piezoelectric transducers 128 may be used in combination with the plurality of apertures 202. In some embodiments that can be combined with other embodiments described herein, mega-sound energy, such as [missing information], is applied to the fluid within the back-side distributor assembly 226 before the fluid leaves the back-side distributor assembly 226. Figure 2 As shown. Alternatively or additionally, mega-sound energy is applied to the fluid on the front side of the substrate.

[0043] Figure 3 This is a process flow diagram of a method 300 for processing substrate 102 according to an embodiment. In operation 302, substrate 102, which is mounted on substrate support 204, is rotated. Substrate 102 is positioned on a single substrate rotation station, such as... Figure 1 and Figure 2As shown. In operation 304, as the substrate rotates, the front side 102a of the substrate 102 is rinsed with cleaning agent from the front nozzle assembly 112. Alternatively or additionally, in operation 306, the back side 102b of the substrate 102 is rinsed with cleaning agent from the back dispenser assembly 126. In some embodiments, operation 304 occurs before operation 306, operations 304 and 306 occur simultaneously with each other, and / or operation 306 occurs before operation 304.

[0044] The back-side dispenser assembly 126 and the front-side nozzle assembly 112 rinse the substrate 102 with cleaning agent during processing. In some embodiments, the front-side nozzle assembly 112 and the back-side dispenser assembly 126 each include a plurality of nozzles capable of simultaneously dispensing cleaning agent. During rinsing, cleaning agent is dispensed simultaneously through the front-side nozzle assembly 112 and the back-side dispenser assembly 126.

[0045] Compared to rinsing with DI water alone, the use of the cleaning agent described improves particle removal rates and is effective at room temperature, thus reducing the need for heating the substrate and maintaining high temperatures required for cleaning. Specifically, the use of a chelating agent (activated using a water-based solvent) improves the removal of both dielectric and metal particles, as well as residual material, thereby improving substrate cleaning. Specifically, cleaning agent rinsing results in particle removal rates of 90% or higher (such as 98%), a significant improvement compared to the mere 50% particle removal rate of DI water.

[0046] Mechanical energy can be used to enhance the kinetic action of the cleaning agent on the wafer surface, which can significantly improve the effectiveness of the cleaning process. Depending on the application, acoustic cavitation (e.g., from megaphonic energy) can be applied from the backplane 105, or a sound source generator can be coupled to one or more nozzles to provide agitation of the cleaning agent to remove residues and particles. Acoustic cavitation involves exciting a fluid on an ultrasonic or megaphonic scale to displace residues and debris. Achieving fluid excitation on an acoustic scale can include operating a piezoelectric transducer (PZT) in a frequency range from a lower ultrasonic range (e.g., about 20 kHz) to a higher megaphonic range (e.g., about 2 MHz). Other frequency ranges can be used. A suitable acoustic energy generator (e.g., a PZT) is rectangular in shape.

[0047] Additionally or alternatively, droplet jet cleaning utilizes the kinetic energy generated by small droplets to improve the removal of contaminants and particles from the substrate surface. By integrating mechanical energy, a more thorough and efficient cleaning process can be achieved, which improves the overall cleanliness and quality of the manufactured semiconductor devices.

[0048] In contrast to traditional brushing methods that rely on direct contact between a brush and the substrate surface, droplet jet cleaning uses a high-speed stream of small droplets to remove contaminants and particles. These droplets range in size from 5 to 50 micrometers and are guided onto the substrate surface using nozzles or other delivery systems.

[0049] Pressurized cleaning solution is pumped through a microfluidic system, creating a fine mist of droplets. These droplets are focused through a precisely aligned array of nozzles and guided toward the substrate surface, allowing control over droplet size, velocity, and spray angle. Upon contact with the substrate surface, these droplets exert localized cleaning forces, effectively displacing and removing contaminants. The high-speed, small droplet size reduces the risk of scratching or damaging the delicate substrate surface. After the cleaning process, the substrate undergoes a rinse with ultrapure water to remove any residual cleaning solution, and is then dried using a nitrogen blower or other drying technology.

[0050] The non-contact nature of droplet jet cleaning significantly reduces the risk of scratches and other surface defects, making it particularly suitable for cleaning advanced and delicate substrate materials. The targeted nature of droplet jetting allows for precise removal of contaminants from specific areas of the substrate, proving especially beneficial for challenging geometries and deep trenches. Compared to brushing, droplet jet cleaning typically requires less cleaning solution, enhancing environmental sustainability and reducing waste generation. The ability to fine-tune droplet size, velocity, and spray angle provides precise control over the cleaning process, resulting in enhanced results.

[0051] In operation 308, the front side 102a and back side 102b of substrate 102 are rinsed using DI water supplied from the front nozzle assembly 112 and the back distributor assembly 126. In some embodiments, the front nozzle assembly 112 and the back distributor assembly 126 each include a plurality of nozzles capable of simultaneously dispensing DI water. During rinsing, DI water is dispensed through the front nozzle assembly 112 and the back distributor assembly 126. Rinsing the substrate removes any displaced residue and debris. Throughout all operations described herein, the substrate continues to rotate.

[0052] Operations 302 to 308, such as front-end-of-line (FEOL) cleaning, are used at or between each stage of substrate 102. For back-end-of-line (BEOL) processing, nitrogen is used in operation 310 to atomize the cleaning agent. In particular, BEOL processing occurs after the substrate has been polished in a CMP process.

[0053] In operation 310, substrate 102 is dried. In some embodiments, the substrate is dried in less than 30 seconds. Drying substrate 102 involves using a surface tension gradient to pull fluid away from the surface of substrate 102, the surface tension gradient being formed at the mixing front between a low surface tension fluid (such as isopropyl alcohol (IPA)) and high surface tension water. The surface tension can be reduced using an IPA spray or vapor, or any suitable spray or vapor that reduces the surface tension of the water dissolved therein. In some embodiments, the IPA is heated to further reduce its surface tension before being applied to the substrate. In some embodiments, the IPA is mixed with nitrogen to provide a mixture of IPA vapor and N2 to be dispensed onto the substrate. Additionally, the drying process used herein rapidly evaporates a thin IPA film at a low rotational rate of about 300 rpm to about 500 rpm, which replaces the water film on the substrate and thus dries the cleaned substrate.

[0054] This disclosure provides a method for cleaning a substrate after CMP, single-cut, or other semiconductor processes, comprising using a chelating agent in a cleaning agent. By combining an effective solvent and a chelating agent, this method effectively removes both dielectric and metal particles, as well as residual material, from the substrate surface. When mixed with DI water in a specific ratio, this method achieves a particle removal rate of 98% or higher, thus surpassing the limitations of conventional DI water cleaning methods.

[0055] When elements of this disclosure or exemplary aspects or embodiments thereof are introduced, the articles “a / an” and “the” are intended to mean the presence of one or more of these elements.

[0056] The terms “contains,” “includes,” and “have” are intended to be inclusive and mean that there may be additional elements besides those listed.

[0057] The term "coupled" is used in this document to refer to a direct or indirect coupling between two objects. For example, if object A physically touches object B and object B touches object C, then object A and object C can still be considered coupled to each other even if they do not directly and physically touch each other. Similarly, even if the first object never directly and physically touches the second object, the first object can still be coupled to the second object.

[0058] Although the foregoing describes embodiments of this disclosure, other and further embodiments may be devised without departing from its essential scope, which is defined by the following claims.

Claims

1. A method for cleaning a substrate, comprising: A substrate that is rotated and mounted on a substrate support; The front side of the substrate is sprayed with a cleaning agent using a front nozzle assembly, wherein the cleaning agent contains one or more chelating agents; as well as The cleaning agent is sprayed onto the back side of the substrate using the back-side dispenser assembly.

2. The method of claim 1, wherein spraying the front side of the substrate comprises applying a jet of the cleaning agent over the substrate support.

3. The method of claim 1, wherein the one or more chelating agents comprise tris(2-hydroxyethyl)methylammonium hydroxide, 2-dimethylaminoethanol, 2-(2-aminoethylamino)ethanol, or combinations thereof.

4. The method of claim 3, wherein the cleaning agent further comprises an organic solvent.

5. The method of claim 4, wherein the organic solvent comprises dimethyl sulfoxide, dimethylacetamide, n-methyl-2-pyrrolidone, diethylene glycol butyl ether, or combinations thereof.

6. The method of claim 4, wherein the cleaning agent further comprises water.

7. The method of claim 1, wherein spraying the back side of the substrate comprises spraying the cleaning agent through a central opening in a back plate disposed beneath the substrate.

8. The method of claim 1, wherein the cleaning agent further comprises an organic base.

9. The method of claim 1, wherein spraying the back side of the substrate comprises spraying the cleaning agent through a plurality of orifices in the back plate.

10. The method of claim 1, further comprising applying mega-acoustic energy to the substrate, wherein one or more transducers are disposed within a backplane.

11. The method of claim 1, wherein dispensing the cleaning agent comprises dispensing the cleaning agent at a rinsing flow rate of about 800 ml / min to about 2000 ml / min.

12. The method of claim 1, further comprising drying the substrate by dispensing isopropanol.

13. A method for cleaning a substrate, comprising: Rotation is configured to support the substrate; as well as The front side of the substrate is sprayed from above using a cleaning agent containing one or more chelating agents via a front nozzle assembly.

14. The method of claim 13, further comprising using the cleaning agent to spray the back side of the substrate.

15. The method of claim 13, further comprising applying mega-sound energy to the substrate, wherein one or more transducers are disposed within a backplane.

16. The method of claim 13, wherein the cleaning agent further comprises an organic solvent, an organic base, and water.

17. The method of claim 13, wherein spraying the front side of the substrate comprises using a front nozzle assembly disposed above the substrate support.

18. The method of claim 14, wherein spraying the back side of the substrate comprises using a back side dispenser assembly disposed below the substrate support.

19. A method for cleaning a substrate, comprising: A substrate that is rotated and mounted on a substrate support; The front side of the substrate is sprayed with a cleaning agent containing one or more chelating agents using a front nozzle assembly positioned above the substrate support. The cleaning agent is sprayed onto the back side of the substrate using a back-side dispenser assembly located below the substrate support.

20. The method of claim 19, wherein the cleaning agent further comprises an organic solvent, an organic base, and water.

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