Post-Chemical Mechanical Planarization (CMP) Cleaning

Abstract

The present invention provides a cleaning composition comprising water; one or more organic acids; at least two surfactants, wherein a first type of surfactant is a diphenyldisulfone surfactant and a second type of surfactant has a surface tension of less than 50 dynes / cm at a concentration of 0.01 wt % in water, and the second type of surfactant is not a surfactant of the first type; and optionally a fluorine compound, a polymer, a corrosion inhibitor, a biological preservative, and a pH adjuster.

Description

[Technical Field]

[0001] This application claims priority to U.S. Provisional Application No. 63 / 071,906, filed August 28, 2020, the entire contents of which are incorporated herein by reference for all permissible purposes. [Background technology]

[0002] In processes involving the fabrication of semiconductor devices, cleaning is required at various steps to remove organic and inorganic residues. Cleaning to improve desired residue removal in semiconductor manufacturing processes includes post-CMP (chemical mechanical planarization) cleaning, photoresist ash residue removal, photoresist removal, pre-probe wafer cleaning, and various applications in post-packaging processes such as dicing and grinding.

[0003] There is a particular need for improved cleaning in post-CMP cleaning of various structures formed by chemical mechanical planarization (CMP) processes, which involve polishing one or more film layers deposited on a wafer by pressing the wafer against a polishing pad with a CMP slurry, which provides abrasive effect for material removal and provides planarity.

[0004] After the CMP process, the wafer surface contains numerous defects that, if not cleaned from the surface, will result in defective chips as the final product. Typical defects after the CMP process include inorganic particles, organic residues, chemical residues, reaction products on the surface due to the interaction of the wafer surface with the CMP slurry, and the buildup of undesirable metals on the surface. After the polishing process, the wafer is most commonly cleaned using a brush scrubbing process. During this process, cleaning chemistry is dispensed onto the wafer to clean it. The wafer is also rinsed with deionized (DI) water before a drying process is performed.

[0005] Prior works generally conducted in the field of this application include US2019 / 0390139, JP11-181494; U.S. Patent No. 6,440,856; U.S. Patent No. 7,497,966 B2; U.S. Patent No. 7,427,362 B2; U.S. Patent No. 7,163,644 B2; PCT / US2007 / 061588; U.S. Patent No. 7,396,806; U.S. Patent No. 6,730,644; U.S. Patent No. 7,084,097; U.S. Patent No. 6,147,002; US2003 / 0129078; and US2005 / 0067164.

[0006] As technology advances, the threshold size and number of defects critical to semiconductor wafer production yield decreases, thereby increasing the performance requirements for post-CMP cleaning materials. The formulations or compositions (formulations and compositions are interchangeable) of the present invention have been found to be highly effective in removing residues left by the CMP polishing process described above. Summary of the Invention

[0007] Described herein are post-CMP cleaning compositions or formulations, methods, and systems for post-CMP processes.

[0008] In one aspect, described herein is a post-CMP cleaning composition (or formulation), comprising: at least one organic acid or salt thereof; At least two surfactants, at least two surfactants, wherein at least one of the at least two surfactants is a first type of surfactant having at least two sulfonic acid groups, and at least one of the at least two surfactants is a second type of surfactant that is not the first type of surfactant; and water; Including, Optionally, Fluoride compounds; a water-soluble polymer or copolymer; corrosion inhibitors; Biological preservatives; and pH adjuster, Includes:

[0009] The post-CMP cleaning composition has a pH of 1-7, preferably 2-6, and more preferably 3-6.

[0010] The composition can be diluted 2 to 500 times with deionized water before use.

[0011] Examples of the first type of surfactant include, but are not limited to, diphenyldisulfonic acid surfactants having diphenyldisulfonic acid or a salt thereof.

[0012] Examples of the second type of surfactant include, but are not limited to, nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and combinations thereof.Preferably, the second type of surfactant is selected from the group consisting of anionic surfactants, nonionic surfactants, amphoteric surfactants, and combinations thereof, and more preferably, the second type of surfactant is selected from the group consisting of anionic surfactants, amphoteric surfactants that exhibit anionic properties in the composition, and combinations thereof.In another preferred embodiment, the second type of surfactant is a nonionic surfactant.In another preferred embodiment, the second type of surfactant is a nonionic surfactant containing an ethylene oxide (EO) group or a polypropylene oxide (PO) group, or both an EO group and a PO group.

[0013] The second type of surfactant can increase the magnitude of the zeta potential of a surface that includes a dielectric material.

[0014] The second type of surfactant has a surface tension of less than 50 dynes / cm at a concentration of 0.01% by weight in water, preferably less than 45 dynes / cm at a concentration of 0.01% by weight in water, and more preferably less than 40 dynes / cm at a concentration of 0.01% by weight in water.

[0015] The second type of surfactant can reduce the contact angle on the cleaning surface.

[0016] The surfactant concentration of any of the surfactant types can be 0.001 to 2% by weight, preferably 0.01 to 0.75% by weight, and more preferably 0.01 to 0.5% by weight.

[0017] The formulation optionally contains a fluoride compound. Examples of fluoride compounds include hydrofluoric acid, ammonium fluoride, ammonium bifluoride, and quaternary ammonium fluorides. A preferred compound is ammonium fluoride. The concentration of the fluoride component in the formulation is preferably in the range of 1 to 25% by weight, preferably 1.25 to 20% by weight, more preferably 1.5 to 15% by weight, and most preferably 2 to 10% by weight.

[0018] The formulation may optionally contain one or more water-soluble polymers or copolymers. The polymer may be selected from the group including, but not limited to, acrylic acid-acrylamidopropanesulfonic acid copolymer, poly(acrylic acid), poly(methacrylic acid), poly(2-acrylamido-2-methyl-1-propanesulfonic acid), carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, poly(1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate), poly(sodium 4-styrenesulfonate), poly(ethylene oxide), poly(4-styrenesulfonic acid), polyacrylamide, poly(acrylamide / acrylic acid) copolymer, and combinations thereof, as well as salts thereof. In a preferred embodiment, the polymer is a polymer or copolymer containing polyacrylic acid or sulfonic acid groups.

[0019] The water-soluble polymer or copolymer is used at a concentration ranging from 0.01 to 10% by weight, preferably from 0.1 to 5% by weight.

[0020] The formulation optionally includes an organic acid selected from the group consisting of monocarboxylic acids, dicarboxylic acids, hydroxycarboxylic acids, and polycarboxylic acids. Examples include, but are not limited to, oxalic acid, citric acid, maleic acid, malic acid, malonic acid, gluconic acid, glutaric acid, ascorbic acid, formic acid, acetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, glycine, α-alanine, and cystine. Preferred organic acids are oxalic acid and citric acid. The concentration of the organic acid in the formulation may be in the range of 1 to 30% by weight, more preferably in the range of 5 to 20% by weight.

[0021] The compositions of the present invention can be used to clean semiconductor wafers containing at least one or more metal or dielectric films on their surfaces. The metal films can include interconnect metal lines or vias containing copper, tungsten, cobalt, aluminum, ruthenium, or alloys thereof. The dielectric layer can be a silicon oxide film, such as that obtained from a tetraethyl orthosilicate (TEOS) precursor, or a dielectric film containing one or more elements such as silicon, carbon, nitrogen, oxygen, and hydrogen. The dielectric film can be porous or non-porous, or the structure can include voids.

[0022] In another aspect, described herein is a post-chemical mechanical planarization (CMP) cleaning method for a semiconductor wafer comprising at least one surface selected from the group consisting of a metal film, a dielectric film, and combinations thereof, the method comprising: Providing a semiconductor wafer; providing a post-chemical mechanical planarization (CMP) cleaning composition as described above; cleaning a semiconductor wafer with the post-CMP cleaning composition; Including, The metal film is selected from the group consisting of tungsten, copper, cobalt, ruthenium, aluminum, and combinations thereof.

[0023] Therein, the method removes metal residues selected from the group consisting of Fe, W, Ti, TiN, and combinations thereof from at least one surface.

[0024] The cleaning composition can be used to clean the wafer surface with various types of cleaning techniques, including but not limited to brush box cleaning, spray cleaning, megasonic cleaning, buffing on a pad, single wafer spray tools, batch immersion cleaning tools, and the like.

[0025] In yet another aspect, described herein is a system for post-chemical mechanical planarization (CMP) cleaning of a semiconductor wafer comprising at least one surface selected from the group consisting of a metal film, a dielectric film, and combinations thereof, comprising: a semiconductor wafer; a post-chemical mechanical planarization (CMP) cleaning composition as described above; Including, At least one surface is in contact with the post-CMP cleaning composition, and the metal film is selected from the group consisting of tungsten, copper, cobalt, ruthenium, aluminum, and combinations thereof.

[0026] In a preferred embodiment, the cleaning composition when diluted with water is capable of etching a dielectric film at an etch rate of preferably 0.2 to 50 angstroms / minute, more preferably 1 to 20 angstroms / minute, and most preferably 1 to 10 angstroms / minute.

[0027] In certain preferred embodiments, the cleaning composition when diluted with water is capable of etching dielectric films at an etch rate between 1 and 10 Angstroms / minute, etching tungsten at an etch rate of less than 1 Angstrom / minute, and etching titanium nitride films at an etch rate of less than 5 Angstroms / minute at room temperature.

[0028] In the accompanying drawings, which form a material part of this specification, there is shown: [Brief explanation of the drawings]

[0029] [Figure 1]Contact angle as a function of time for formulations with different ratios of the two surfactants. DETAILED DESCRIPTION OF THE INVENTION

[0030] Described and disclosed herein are compositions for cleaning in semiconductor manufacturing, including various applications in post-CMP (Chemical Mechanical Planarization) cleaning, photoresist ash residue removal, photoresist removal, pre-probe wafer cleaning, dicing, grinding, and other post-processing packages. The formulations are suitable as post-CMP cleaning formulations.

[0031] The formulations of the present invention are particularly useful as post-CMP cleaning formulations after CMP processes, including metal CMP processes in which the CMP process forms metal wiring structures surrounded by a dielectric, and dielectric CMP processes in which one or more dielectrics are polished to form planar surfaces or structures. Examples of metal CMP processes include, but are not limited to, tungsten CMP, copper CMP, cobalt CMP, ruthenium CMP, and aluminum CMP, which form metal lines or vias separated by dielectric regions. Examples of dielectric CMP include shallow trench isolation (STI) CMP, which forms silicon oxide film structures separated by silicon nitride regions and interlayer dielectric (ILD) polishing.

[0032] In one preferred embodiment, the cleaning formulation of the present invention is used for post-CMP cleaning after tungsten CMP. The formulation of the present invention is particularly effective in removing metal residues, such as Fe, W, Ti, and TiN, that typically form on wafer surfaces after tungsten CMP, while significantly improving organic and inorganic residue removal. The formulation of the present invention is suitable for reducing tungsten corrosion, reducing surface roughness, and reducing galvanic corrosion between tungsten and liner materials.

[0033] The cleaning formulations are made with water as a solvent. The formulations are preferably made in the form of a concentrate, and although the formulations can also be supplied as point-of-use formulations, they are diluted with water at the time of use to reduce manufacturing, shipping, and handling costs. Concentrated formulations can be diluted from 1:1 (1 part formulation: 1 part water by weight) to 1000:1 (1 part formulation: 1000 parts water by weight) at the time of use. The concentrations provided for additives in the cleaning formulations are those of concentrates that can be diluted 1:1 to 1000:1, preferably 5:1 to 100:1, and most preferably 25:1 to 75:1.

[0034] 1. A post-chemical mechanical planarization (CMP) cleaning composition comprising: at least one organic acid or salt thereof; At least two surfactants, at least two surfactants, wherein at least one of the at least two surfactants is a first type of surfactant having at least two sulfonic acid groups, and at least one of the at least two surfactants is a second type of surfactant that is not the first type of surfactant; and water; Including, Optionally, Fluoride compounds; a water-soluble polymer or copolymer; corrosion inhibitors; Biological preservatives; and pH adjuster, Includes:

[0035] Organic Acid or Mixtures Thereof: The organic acid can be selected from a wide range of acids, including monocarboxylic acids, dicarboxylic acids, polycarboxylic acids, hydroxycarboxylic acids, or mixtures thereof. Specific examples of organic acids include, but are not limited to, oxalic acid, citric acid, maleic acid, malic acid, malonic acid, gluconic acid, glutaric acid, ascorbic acid, formic acid, acetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, glycine, α-alanine, cystine, and the like. Polycarboxylic acids are organic acid molecules containing multiple carboxylic acid groups. Polymers having monomers containing carboxylic acid groups are not considered polycarboxylic acids in this application. Salts of organic acids may also be used. Similarly, acid / salt mixtures may be used. Organic acids function to enhance trace metal removal, remove organic residues, adjust pH, and inhibit metal corrosion.

[0036] In one embodiment, the cleaning composition comprises one or more organic acids selected from oxalic acid, citric acid, malonic acid, glycine, and α-alanine. Another embodiment of the cleaning composition comprises a mixture of oxalic acid, citric acid, and malonic acid. In another preferred embodiment, the organic acid comprises citric acid. In another embodiment, the organic acid comprises a mixture of citric acid and oxalic acid.

[0037] The cleaning chemistry may include 0.1% to 30% by weight of organic acids and / or salts thereof. Preferred acid concentrations are in the range of 5% to 20% by weight.

[0038] In some preferred embodiments, the first type of surfactant will have two or more sulfonic acid groups. Preferred surfactants are those having diphenyldisulfonic acid or its salts.

[0039] Examples of surfactants having such structures include: (a) [ka] (b) [ka] (c) [ka] (d) [ka] (e), and [ka] (f), [ka] Examples include:

[0040] Commercially available anionic surfactants having diphenyl disulfonic acid include the Dowfax® series from Dow Chemical Company: TM 2A1 (structure b), Dowfax TM 3b2 (structure d), Dowfax TM C6L (Structure e) and Dowfax TM 8390 (structure f); as well as the Calfax® series from Pilot Chemical Company: Calfax® DBA-70, Calfax® 10L-45, Calfax® 16L-35, Calfax® 6LA-70, etc. Because semiconductor applications require high purity chemicals with very low levels of mobile ions such as sodium, surfactant solutions can be purified by suitable techniques, including ion exchange, to remove metal ions.

[0041] The post-CMP formulation also includes at least one second surfactant that does not contain a diphenyldisulfonic acid group. Suitable second surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and mixtures thereof. The purpose of the second surfactant is to provide solution properties that are not available when using the diphenyldisulfonic acid surfactant alone.

[0042] Solutions containing diphenyl disulfonic acid surfactants typically have a reasonably high surface tension and high contact angle on the cleaning surface. A second type of surfactant with appropriate properties can also provide additional benefits in terms of surface modification of various film surfaces, particles, and residues, which can improve the cleaning performance of post-CMP cleaning solutions. Therefore, a second type of surfactant with superior wetting properties is desired in combination with a diphenyl disulfonic acid surfactant. In a preferred embodiment, the second type of surfactant has a surface tension of less than 50 dynes / cm at a concentration of 0.01 wt% in water, more preferably less than 45 dynes / cm at a concentration of 0.01 wt% in water, or most preferably less than 40 dynes / cm at a concentration of 0.01 wt% in water.

[0043] Nonionic surfactants can be selected from a range of chemical types including, but not limited to, long chain alcohols, ethoxylated alcohols, ethoxylated acetylenic diol surfactants, polyethylene glycol alkyl ethers, propylene glycol alkyl ethers, glucoside alkyl ethers, polyethylene glycol octylphenyl ethers, polyethylene glycol alkylpgenyl ethers, glycerol alkyl esters, polyoxyethylene glycol sorbitone alkyl esters, sorbitone alkyl esters, cocamide monoethanolamine, cocamide diethanolamine dodecyldimethylamine oxide, block copolymers of polyethylene glycol and polypropylene glycol, polyethoxylated tallowamine, fluorosurfactants.

[0044] Anionic surfactants include, but are not limited to, suitable hydrophobic tails and anionic functional groups, such as carboxylates, sulfates, sulfonates, secondary asulfonates, phosphates, bicarboxylates, hydrogen sulfates, biphosphates, such as alkoxycarboxylates, alkoxysulfates, and alkoxyphosphates. Counterions for this type of surfactant include, but are not limited to, potassium, ammonium, and other cations. The hydrophobic group may include an alkyl group, an aryl group, an alkoxy group, or a combination thereof.

[0045] Cationic surfactants have a net positive charge on the main part of the molecular backbone. Cationic surfactants are typically halide molecules containing a hydrophobic chain and a cationic charge center, such as an amine, quaternary ammonium, benzalkonium, or alkylpyridinium ion.

[0046] In other embodiments, surfactants can be amphoteric surfactants, which have both positive (cationic) and negative (anionic) charges in the main molecular chain and associated counterions. The cationic portion is based on a primary, secondary, or tertiary amine or quaternary ammonium cation. The anionic portion is more diverse and can include sulfonates such as CHAPS (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate) and cocamidopropyl hydroxysultaine, among other sultaines. Betaines, such as cocamidopropyl betaine, have ammonium-containing carboxylates. Some amphoteric surfactants may have amine- or ammonium-containing phosphate anions, such as the phospholipids phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine, and sphingomyelin.

[0047] In another preferred embodiment, the second type of surfactant is a nonionic surfactant. In another preferred embodiment, the second type of surfactant is a nonionic surfactant containing an ethylene oxide (EO) group or a polypropylene oxide (PO) group, or both an EO group and a PO group. Examples of preferred second type of surfactants include C 2 surfactants, such as the anionic surfactant Hostapur SAS® series manufactured by Clariant. 12 ~C 17 It is a surfactant containing a secondary alkane sulfonic acid having a hydrophobic chain. Another example of a preferred second type of surfactant is Tergitol® Minfoam 1× manufactured by Dow Chemicals.

[0048] The formulation comprises at least one surfactant that has two or more anionic groups.Without being bound by any particular theory, it can be assumed that the surfactant that has two or more anionic groups is likely to have sufficient electrostatic field even in high ionic solution.Therefore, the surfactant solution is stable against the structure that causes surfactant molecule to collapse and the solution to become cloudy.

[0049] The molecular weight of the surfactant, as measured by a suitable technique such as, but not limited to, gel permeation chromatography (GPC), may range from one hundred to over ten million.

[0050] The surfactant concentration of either surfactant type can range from 0.001 to 2% by weight, preferably from 0.01 to 0.75% by weight, more preferably from 0.01 to 0.5% by weight.

[0051] The cleaning formulation may optionally contain a water-soluble polymer additive. The polymer may be a homopolymer or a copolymer. The polymer may be selected from the group consisting of, but not limited to, acrylic acid-acrylamidopropanesulfonic acid copolymer, poly(acrylic acid), poly(methacrylic acid), poly(2-acrylamido-2-methyl-1-propanesulfonic acid), carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, poly(1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate), poly(sodium 4-styrenesulfonate), poly(ethylene oxide), poly(4-styrenesulfonic acid), polyacrylamide, poly(acrylamide / acrylic acid) copolymer, and combinations and salts thereof. The molecular weight of the polymer, as measured by a suitable technique such as GPC (gel permeation chromatography), may range from 100 to 10,000,000.

[0052] Preferred polymers are those containing copolymers of monomers having sulfonic acid groups, acrylic acid groups, or sulfonic acid groups and acrylic acid groups.

[0053] The addition of polymers to post-CMP formulations with an appropriate base results in significant improvements in cleaning performance. The mechanism of this improvement is still under investigation. One possibility is physical adsorption to the surface, which prevents redeposition of removed particles and other residues. Another possible mechanism is a higher affinity for residues (organics), which increases the driving force for lift-off during the cleaning process.

[0054] These types of polymers or mixtures thereof can be added to cleaning formulations at concentrations of 0.01 to 10% by weight. A preferred concentration range is between 0.1% and 5% by weight. The formulations can be diluted 2 to 500 times at the time of use by adding a solvent such as water. Alternatively, they can be supplied in a diluted state for direct use without dilution at the time of use.

[0055] The formulation also optionally contains a fluoride compound. Examples of fluoride compounds include hydrofluoric acid, ammonium fluoride, ammonium bifluoride, and quaternary ammonium fluorides. A preferred compound is ammonium fluoride. The concentration of the fluorine component in the formulation is 1 to 25% by weight, preferably 1.25 to 20% by weight, more preferably 1.5 to 15% by weight, and most preferably 2 to 10% by weight. The formulation is diluted 2 to 500 times before use.

[0056] Examples of pH adjusters that can be used include inorganic acids such as nitric acid, sulfonic acid, and phosphoric acid, inorganic bases such as ammonium hydroxide, potassium hydroxide, and sodium hydroxide, organic bases such as quaternary ammonium hydroxide, and various amine compounds.

[0057] The pH of the formulation is preferably 1-7, more preferably 2-6, most preferably 3-6.

[0058] The formulation can be diluted 2 to 500 times with DI water at the time of use.

[0059] For post-CMP cleaning formulations, there may be additional ingredients that aid in cleaning performance. Common types of additives include:

[0060] The cleaning chemistry may optionally include a chelating agent.

[0061] Because chelating agents may be more selective for some metal ions than others, multiple chelating agents or salts thereof are used in the compositions described herein.It is believed that these chelating agents can bind to metal ion contaminants on the substrate surface and dissolve them in the composition.Furthermore, in certain embodiments, the chelating agent should be able to retain these metal ions in the composition and prevent the ions from redepositing on the substrate surface. Examples of suitable chelating agents that can be used include ethylenediaminetetraacetic acid (EDTA), N-hydroxyethylethylenediaminetriacetic acid (NHEDTA), nitrilotriacetic acid (NTA), diethylcleotriaminepentaacetic acid (DPTA), ethanol diglycinate, citric acid, gluconic acid, oxalic acid, phosphoric acid, tartaric acid, methyldiphosphonic acid, aminotrimethylenephosphonic acid, ethylidenediphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, 1-hydroxypropylidene-1,1-diphosphonic acid, ethylaminobismethylenephosphonic acid, dodecylaminobismethylenephosphonic acid, nitrilotrismethylenephosphonic acid, ethylenediaminebismethylenephosphonic acid, ethylenediaminetetrakismethylenephosphonic acid, hexadiaminetetrakismethylenephosphonic acid, diethylaminob ... Examples of the carboxylic acid additive include, but are not limited to, lenthriamine pentamethylene phosphonic acid and 1,2-propanediamine tetramethylene phosphonic acid or ammonium salts, organic amine salts, polycarboxylic acids such as malonic acid, succinic acid, dimercaptosuccinic acid, glutaric acid, maleic acid, phthalic acid, fumaric acid, tricarballylic acid, propane-1,1,2,3-tetracarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, and pyromellitic acid, oxycarboxylic acids such as glycolic acid, β-hydroxypropionic acid, citric acid, malic acid, tartaric acid, pyruvic acid, diglycolic acid, salicylic acid, and gallic acid, polyphenols such as catechol and pyrogallol, phosphoric acids such as pyrophosphoric acid and polyphosphoric acid, heterocyclic compounds such as 8-oxyquinoline, and diketones such as α-dipyridylacetylacetone.

[0062] The chelating agent can be used at a concentration ranging from 0.01% to 30% by weight.

[0063] The cleaning chemistry can optionally include an anti-foaming compound. A defoamer or anti-foaming agent is a chemical additive that reduces and prevents foam formation in a formulation. The terms anti-foaming agent and defoamer are often used interchangeably. Commonly used agents include insoluble oils, polydimethylsiloxanes and other silicones, certain alcohols, stearates and glycols, certain surfactants such as combinations of polyether surfactants and polyhydric alcohol fatty acid esters, and Surfynol MD20 surfactant from Emonik Chemicals. Anti-foaming compounds can be used in cleaning formulations at concentrations ranging from 0.00001% to 0.01% by weight.

[0064] The cleaning chemistry can optionally include a biocide. CMP formulations may also include additives for controlling biological growth, such as biocides. Some additives for controlling biological growth are disclosed in U.S. Pat. No. 5,230,833 (Romberger et al.) and U.S. Patent Application Publication No. 2002 / 0025762, which are incorporated herein by reference. Biological growth inhibitors include, but are not limited to, tetramethylammonium chloride, tetraethylammonium chloride, tetrapropylammonium chloride, alkylbenzyldimethylammonium chloride, and alkylbenzyldimethylammonium hydroxide, where the alkyl chain has from 1 to about 20 carbon atoms, sodium chlorite, sodium hypochlorite, and isothiazolinone compounds, such as methylisothiazolinone, methylchloroisothiazolinone, and benzisothiazolinone. Some commercially available preservatives include KATHON, manufactured by Dow Chemicals. TM and NEOLENE TM Product family and Preventol by Lanxess TM Family is one example.

[0065] Preferred biocides are isothiodione compounds such as methylisothiazolinone, methylchloroisothiazolinone and benzisothiazolinone.

[0066] The formulation may contain a biocide in the range of 0.0001% to 0.10% by weight, preferably 0.0001% to 0.005% by weight, more preferably 0.0002% to 0.0025% by weight to prevent bacterial and fungal growth during storage.

[0067] The chemicals can be used in a variety of cleaning applications requiring the removal of residues from surfaces. The residues can be inorganic or organic in nature. Examples of processes in which formulations containing these polymers can be effective include post-CMP cleaning, photoresist ash residue removal, photoresist removal, and various applications in back-end packaging such as pre-probe wafer cleaning, dicing, grinding, and wafer cleaning for photovoltaic applications.

[0068] The compositions of the present invention are particularly suitable for cleaning semiconductor wafers containing at least one or more metal or dielectric films on their surfaces. The metal films can include interconnect metal lines or vias containing copper, tungsten, cobalt, aluminum, ruthenium, germanium-antimony-tellurium (GST), or alloys thereof. The dielectric layer can be a silicon oxide film, such as that obtained from a tetraethyl orthosilicate (TEOS) precursor, or a dielectric film containing one or more elements such as silicon, carbon, nitrogen, oxygen, and hydrogen. The dielectric film can be porous or non-porous, or the structure can include voids.

[0069] The cleaning composition can be used to clean the wafer surface with various types of cleaning techniques, including, but not limited to, brush box cleaning, spray cleaning, megasonic cleaning, buffing on a pad, single wafer spray tools, batch immersion cleaning tools, etc., or a combination of such methods.

[0070] In certain preferred embodiments, the cleaning composition when diluted with water is capable of etching dielectric films at room temperature at an etch rate preferably between 0.2 and 50 Angstroms / minute, more preferably between 1 and 20 Angstroms / minute.

[0071] In some preferred embodiments, the room temperature etch rates of metal films (tungsten and titanium nitride) are very low, preferably less than 10 Angstroms / minute, more preferably less than 5 Angstroms / minute, and most preferably less than 2 Angstroms / minute.

[0072] The formulations of the present invention are particularly suitable for tungsten post-CMP cleaning applications. Tungsten CMP produces metal residues, including W, Ti, and Fe, that can form invisible residues on dielectric surfaces. These residues can increase leakage current and reduce the effectiveness of semiconductor devices. Titanium, in particular, is very difficult to remove from wafer surfaces because it is generally stable as a solid oxide phase over a wide pH range. The formulations of the present invention, with their appropriate organic acid and dielectric etching capabilities, can effectively remove titanium residues and improve device electrical performance.

[0073] It is desirable for post-CMP cleaning solutions to have low turbidity. High turbidity can interfere with measuring the number of particles present in the solution, which is important for quality control of post-CMP cleaning solutions. Turbidity can be measured using appropriate optical techniques. Turbidity values ​​are typically measured by shining a light onto a solution sample and measuring the amount of light scattered by substances in the solution. The higher the intensity of the scattered light, the higher the turbidity. Nephelometric Turbidity Units (NTU) are commonly used as a unit of measurement for turbidity. It is desirable for the turbidity of post-CMP cleaning solutions to be less than 5 NTU, preferably less than 2.5 NTU, more preferably less than 2.0 NTU, and most preferably less than 1 NTU.

[0074] In another aspect, described herein is a post-chemical mechanical planarization (CMP) cleaning method for a semiconductor wafer comprising at least one surface selected from the group consisting of a metal film, a dielectric film, and combinations thereof, the method comprising: providing a semiconductor wafer; providing the post-chemical mechanical planarization (CMP) cleaning composition; cleaning a semiconductor wafer with the post-CMP cleaning composition; Including, The metal film is selected from the group consisting of tungsten, copper, cobalt, ruthenium, aluminum, and combinations thereof.

[0075] Therein, the method removes metal residues selected from the group consisting of Fe, W, Ti, TiN, and combinations thereof from at least one surface.

[0076] In yet another aspect, described herein is a system for post-chemical mechanical planarization (CMP) cleaning of a semiconductor wafer comprising at least one surface selected from the group consisting of a metal film, a dielectric film, and combinations thereof, comprising: a semiconductor wafer; a post-chemical mechanical planarization (CMP) cleaning composition as described above; Including, At least one surface is in contact with the post-CMP cleaning composition, and the metal film is selected from the group consisting of tungsten, copper, cobalt, ruthenium, aluminum, and combinations thereof.

[0077] In certain preferred embodiments, the cleaning composition when diluted with water is capable of etching dielectric films at an etch rate between 1 and 10 Angstroms / minute, etching tungsten at an etch rate of less than 1 Angstrom / minute, and etching titanium nitride films at an etch rate of less than 5 Angstroms / minute at room temperature.

[0078] It should be understood that the cleaning compositions, methods and systems described herein will be further illustrated by reference to the following examples, but are not to be construed as being limited thereto. [Example]

[0079] Example 1 Concentrated formulations were made as shown in Table 1.

[0080] One part by weight of the formulation was diluted with 49 parts by weight of water.

[0081] The zeta potential of the tungsten and TEOS surfaces was measured using a surface zeta potential cell on a Zetasizer Nano tool (Malvern Instruments Inc. 117 Flanders Road Westborough MA 01581-1042) by adding high purity silica particles as the microparticles.

[0082] The surfactants were used in their acid form.

[0083] The data is C 12 Calfax® DBA-70 from Pilot Chemical Company, 9075 Centre Pointe Drive, Suite 400, West Chester, OH 45069, a diphenyl disulfonic acid containing hydrophobic chains, has been shown to be very effective for increasing the magnitude of the zeta potential of tungsten surfaces.

[0084] On the other hand, C 12 ~C 17 A second type of surfactant, Hostapur SAS® (anionic surfactant) from Clariant, which is a secondary alkane sulfonic acid containing a hydrophobic chain (not a diphenyl disulfonic acid surfactant), is more effective at increasing the magnitude of the zeta potential of the TEOS surface. [Table 1]

[0085] The change in surface zeta potential due to surfactants strongly indicates their ability to modify the film surface through adsorption, making it easier to clean. The increase in the magnitude of the negative zeta potential is thought to be related to the anionic groups in the surfactant. The zeta potential change was measured without the use of ammonium fluoride, using a pH of 2.55.

[0086] The combination of two surfactants, one in the form of diphenyldisulfonic acid, provided powerful surface modification of both the metal (tungsten in this example) and the dielectric (TEOS in this example), essential for cleaning patterned wafers containing both metal and dielectric surfaces.

[0087] Example 2 To Formulation 1 in Table 1, both Calfax® DBA-70 and Hostapur® SAS surfactants were added to make different formulations.

[0088] First, Formulation 1 was diluted with 49 parts by weight of water to make a 50-fold dilution.

[0089] Next, surfactant was added to the dilution solution, and the total surfactant concentration in the dilution solution was fixed at 60 ppm.

[0090] The fraction of each individual surfactant in the surfactant mixture was varied between 0 and 100% of the total surfactant amount.

[0091] The tungsten film was kept at 50°C for 4 days to create a hydrophobic tungsten surface.

[0092] The contact angle of the tungsten film surface was measured as a function of time after placing a drop on the film, and the measured contact angles are shown in Figure 1.

[0093] As can be seen from this figure, increasing the amount of surfactant Calfax® DBA 70 had little effect on reducing the contact angle. A second type of surfactant, Hostapur® SAS, was very effective at reducing the contact angle (as shown in the 0% Calfax® DBA curve). Adding Calfax® DBA surfactant up to 33% of the total surfactant significantly reduced the contact angle with tungsten.

[0094] Example 3 Formulation 6 was prepared as described in Table 2. [Table 2]

[0095] Various concentrations of surfactant were added in Formulation 6 as shown in Table 3.

[0096] In Table 3, Surfactant 1 was the Dowfax® series from Dow Chemical Company. Surfactant 1 was a diphenyl disulfonic acid surfactant with a different structure.

[0097] The second type of surfactant in Table 3, Surfactant 2 Hostapur® SAS, was not a diphenyldisulfonic acid surfactant.

[0098] The stability of the formulations was measured by turbidity measurements using a Hatch turbidity test tool. Table 3 summarizes the turbidity data.

[0099] The addition of Surfactant 2 Hostapur® SAS to Formulation 6 results in a very high turbidity (29.6) as evidenced by the turbidity data for Formulation 7.

[0100] However, when diphenyl disulfonic acid surfactant 1 was added, the turbidity decreased.

[0101] Most solutions containing these surfactants had turbidities below 2 NTU, indicating clear, transparent solutions, demonstrating the unexpected ability of the diphenyldisulfonic acid surfactants to solubilize a second surfactant. [Table 3]

[0102] Example 4 Formulation 20 was prepared as described in Table 4. [Table 4]

[0103] To this formulation, various concentrations (wt %) of surfactants were added, as shown in Table 5.

[0104] Turbidity measurements of various surfactant combinations were performed using a Hatch turbidity test tool. [Table 5]

[0105] Table 5 summarizes the turbidity data.

[0106] Calfax® DBA-40 is a C 12 It is a (branched) diphenyl disulfonic acid surfactant.

[0107] Other surfactants were purchased from Millipore Sigma (400 Summit Drive, Burlington 01803 USA).

[0108] It is clear from the table that the addition of diphenyl disulfonic acid surfactants can reduce the turbidity of post-CMP cleaning solutions containing a wide range of surfactants.

[0109] Example 5 Formulations were prepared as shown in Table 6 and subjected to turbidity testing.

[0110] Tergitol TM Min Foam 1x is a surfactant containing ethylene oxide and propylene oxide groups manufactured by Dow Chemicals. [Table 6]

[0111] Table 6 summarizes the turbidity data.

[0112] It is clear from the table that the addition of the diphenyl disulfonic acid surfactant Calfax® DBA-40 can reduce the turbidity of the post-CMP cleaning solutions. All solutions containing Calfax® DBA-40 had a turbidity of less than 2 NTU, indicating a clear, transparent solution. This again demonstrates the unexpected ability of the diphenyl disulfonic acid surfactant to solubilize Tergitol Min-Foam 1x.

[0113] Example 6 The surface tension of various surfactants was measured using the dimensionless drop method with a Rame-Hart 590 tool (manufactured by Rame-Hart Instrument Co., 19 Route 10 East, Suite 11, Succasunna, NJ 07876, USA). This tool calculates the surface tension of the liquid using a contour fitting algorithm and the profile coordinates of the droplet's contour. Table 6 provides the surface tensions of various surfactants at a 0.01% concentration in water. [Table 7]

[0114] As can be seen from Table 7, diphenyl disulfonic acid surfactants, such as Calfax® DBA-40, have high surface tension values ​​at a given concentration. A second surfactant with a lower surface tension value is needed to lower the surface tension of the cleaning solution.

[0115] While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept. Examples of embodiments of the present invention are listed in the following items [Aspect 1] to [Aspect 32]. [Aspect 1] 1. A post-chemical mechanical planarization (CMP) cleaning composition comprising: at least one organic acid or salt thereof; At least two surfactants, at least two surfactants, wherein at least one of the at least two surfactants is a first type of surfactant having at least two sulfonic acid groups, and at least one of the at least two surfactants is a second type of surfactant that is not of the first type of surfactant; and water; Including, Optionally, Fluoride compounds; a water-soluble polymer or copolymer; corrosion inhibitors; Biological preservatives; and pH adjuster, 1. A post-CMP cleaning composition comprising: [Aspect 2] 2. The post-CMP cleaning composition of embodiment 1, wherein the first type of surfactant is a diphenyldisulfonic acid-based surfactant having diphenyldisulfonic acid or a salt thereof. [Aspect 3] The first type of surfactant is (a)、 [ka] (b)、 [ka] (c)、

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Claims

1. 1. A post-chemical mechanical planarization (CMP) cleaning composition comprising: at least one organic acid or salt thereof; At least two surfactants, at least two surfactants, wherein at least one of the at least two surfactants is a first type of surfactant having at least two sulfonic acid groups, and at least one of the at least two surfactants is a second type of surfactant that is not of the first type of surfactant; and water; Including, Optionally, Fluoride compounds; a water-soluble polymer or copolymer; corrosion inhibitors; Biological preservatives; and pH adjusters, Including, the first type of surfactant is a diphenyldisulfonic acid surfactant having diphenyldisulfonic acid or a salt thereof, A post-CMP cleaning composition wherein the second type of surfactant comprises a secondary alkane sulfonic acid having a C 12 -C 17 hydrophobic chain, and the second type of surfactant has a surface tension of less than 45 dynes / cm at a concentration of 0.01 wt % in water.

2. The first type of surfactant is (a), 【Chemistry 1】 (b), 【Chemistry 2】 (c), 【Transformation 3】 (d), 【Chemistry 4】 (e), and 【Transformation 5】 (f), 【Transformation 6】 10. The post-CMP cleaning composition of claim 1 having a structure selected from the group consisting of:

3. 10. The post-CMP cleaning composition of claim 1, wherein the second type of surfactant increases the magnitude of the zeta potential of a surface comprising a dielectric material.

4. The post-CMP cleaning composition of claim 1 , wherein the second type of surfactant reduces the contact angle on the cleaned surface.

5. 10. The post-CMP cleaning composition of claim 1, wherein the at least one organic acid is selected from the group consisting of monocarboxylic acids, dicarboxylic acids, polycarboxylic acids, hydroxycarboxylic acids, and combinations thereof.

6. 2. The post-CMP cleaning composition of claim 1, wherein the at least one organic acid is selected from the group consisting of oxalic acid, citric acid, maleic acid, malic acid, malonic acid, gluconic acid, glutaric acid, ascorbic acid, formic acid, acetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, glycine, α-alanine, cystine, and combinations thereof.

7. 10. The post-CMP cleaning composition of claim 1, wherein the at least one organic acid is selected from the group consisting of oxalic acid, citric acid, malonic acid, and combinations thereof.

8. 10. The post-CMP cleaning composition of claim 1, wherein the fluoride compound is selected from the group consisting of hydrofluoric acid, ammonium fluoride, ammonium bifluoride, quaternary ammonium fluorides, and combinations thereof.

9. The post-CMP cleaning composition of claim 1 , wherein the fluoride compound is ammonium fluoride.

10. 2. The post-CMP cleaning composition of claim 1, wherein the water-soluble polymer comprises a group selected from the group consisting of a sulfonic acid group, an acrylic acid group, and combinations thereof, and the water-soluble copolymer comprises a monomer having a group selected from the group consisting of a sulfonic acid group, an acrylic acid group, and combinations thereof.

11. 2. The post-CMP cleaning composition of claim 1, wherein the water-soluble polymer or copolymer is selected from the group consisting of acrylic acid-acrylamidopropanesulfonic acid copolymer, poly(acrylic acid), poly(methacrylic acid), poly(2-acrylamido-2-methyl-1-propanesulfonic acid), carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, poly(1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate), poly(sodium 4-styrenesulfonate), poly(ethylene oxide), poly(4-styrenesulfonic acid), polyacrylamide, poly(acrylamide / acrylic acid) copolymer, and combinations thereof, and the molecular weight of the water-soluble polymer or copolymer is in the range of 100 to 10,000,000.

12. 2. The post-CMP cleaning composition of claim 1, wherein the corrosion inhibitor is selected from the group consisting of an oligomer or polymer comprising ethyleneimine, propyleneimine, polyethyleneimine (PEI), and combinations thereof, and the molecular weight of the oligomer or polymer ranges from 500 to 1,000,000.

13. 2. The post-CMP cleaning composition of claim 1, wherein the biological preservative is selected from the group consisting of tetramethylammonium chloride; tetraethylammonium chloride; tetrapropylammonium chloride; alkylbenzyldimethylammonium chloride; alkylbenzyldimethylammonium hydroxide; sodium chlorite; sodium hypochlorite; an isothiazolinone compound selected from the group consisting of methylisothiazolinone, methylchloroisothiazolinone, benzisothiazolinone, and combinations thereof; and combinations thereof.

14. 2. The post-CMP cleaning composition of claim 1, wherein the pH adjuster is selected from the group consisting of an inorganic acid selected from the group consisting of nitric acid, sulfonic acid, or phosphoric acid; an inorganic base selected from the group consisting of ammonium hydroxide, potassium hydroxide, or sodium hydroxide; and an organic base selected from the group consisting of quaternary ammonium hydroxides and amine compounds.

15. The post-CMP cleaning composition of claim 1, wherein the composition has a pH of 1-7.

16. 10. The post-CMP cleaning composition of claim 1, wherein the composition is diluted 2 to 500 times with water at the time of use.

17. The post-CMP cleaning composition of claim 1 , wherein the composition has a turbidity of less than 5 NTU.

18. 2. The post-CMP cleaning composition of claim 1, wherein the composition comprises at least one organic acid selected from the group consisting of oxalic acid, citric acid, malonic acid, and combinations thereof; and the first type surfactant containing two or more sulfonic acid groups is diphenyldisulfonic acid or a salt thereof.

19. 2. The post-CMP cleaning composition of claim 1, wherein the composition comprises at least one organic acid selected from the group consisting of oxalic acid, citric acid, malonic acid, and combinations thereof; the first type of surfactant containing two or more sulfonic acid groups is diphenyldisulfonic acid or a salt thereof; and the fluoride compound is selected from the group consisting of hydrofluoric acid, ammonium fluoride, ammonium difluoride, quaternary ammonium fluorides, and combinations thereof.

20. 2. The post-CMP cleaning composition of claim 1, wherein the composition comprises at least one organic acid selected from the group consisting of oxalic acid, citric acid, malonic acid, and combinations thereof; the first type of surfactant containing two or more sulfonic acid groups is diphenyldisulfonic acid or a salt thereof; the fluoride compound is selected from the group consisting of hydrofluoric acid, ammonium fluoride, ammonium difluoride, quaternary ammonium fluoride, and combinations thereof; and the water-soluble polymer comprises an acrylic acid group or the water-soluble copolymer comprises a monomer having an acrylic acid group.

21. 1. A post-chemical mechanical planarization (CMP) cleaning method for a semiconductor wafer comprising at least one surface selected from the group consisting of a metal film, a dielectric film, and combinations thereof, comprising: providing the semiconductor wafer; Providing the post-chemical mechanical planarization (CMP) cleaning composition of any one of claims 1 to 20; cleaning the semiconductor wafer with the post-CMP cleaning composition; Including, the metal film is selected from the group consisting of tungsten, copper, cobalt, ruthenium, aluminum, and combinations thereof; method.

22. 22. The post-chemical mechanical planarization (CMP) cleaning method of claim 21, wherein the method removes metal residues selected from the group consisting of Fe, W, Ti, TiN, and combinations thereof from the at least one surface.

23. 1. A system for post-chemical mechanical planarization (CMP) cleaning of a semiconductor wafer comprising at least one surface selected from the group consisting of a metal film, a dielectric film, and combinations thereof, comprising: the semiconductor wafer; The post-chemical mechanical planarization (CMP) cleaning composition of any one of claims 1 to 20; Including, the at least one surface is in contact with the post-CMP cleaning composition and the metal film is selected from the group consisting of tungsten, copper, cobalt, ruthenium, aluminum, and combinations thereof; system.

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