Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
  • G03F7/42—Stripping or agents therefor
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
  • G03F7/42—Stripping or agents therefor
  • G03F7/422—Stripping or agents therefor using liquids only
  • G03F7/425—Stripping or agents therefor using liquids only containing mineral alkaline compounds; containing organic basic compounds, e.g. quaternary ammonium compounds; containing heterocyclic basic compounds containing nitrogen
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D11/00—Special methods for preparing compositions containing mixtures of detergents
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/32—Organic compounds containing nitrogen
  • C11D7/3218—Alkanolamines or alkanolimines
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/32—Organic compounds containing nitrogen
  • C11D7/3281—Heterocyclic compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/34—Organic compounds containing sulfur
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
  • G03F7/42—Stripping or agents therefor
  • G03F7/422—Stripping or agents therefor using liquids only
  • G03F7/426—Stripping or agents therefor using liquids only containing organic halogen compounds; containing organic sulfonic acids or salts thereof; containing sulfoxides
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
  • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D2111/00—Cleaning compositions characterised by the objects to be cleaned; Cleaning compositions characterised by non-standard cleaning or washing processes
  • C11D2111/10—Objects to be cleaned
  • C11D2111/14—Hard surfaces
  • C11D2111/22—Electronic devices, e.g. PCBs or semiconductors

Definitions

• the present invention relates to compositions and processes for cleaning, solvating, dissolving, and/or removing debris and residues from substrates. More specifically, it relates to compositions and processes for cleaning polymeric materials and organic, organometallic and metallic oxides from quartzwares. The invention further relates to compositions and methods for cleaning fluxes and resist materials from microcircuits.
• Cleaning solvents are used throughout industry. These solvents are made from various organic and inorganic materials forming compositions differing in functionality and effectiveness. In order for cleaning solvents to be effective, the cleaning solvent, the material to be removed, and the surrounding material or substrate must be examined to insure that the material or residue to be removed can be dissolved, solvated, or removed by the cleaning solvent without damaging the surrounding materials. Several factors, such as pH, polarity, chemical reactivity, and chemical compatibility must be considered when selecting a cleaning solvent. Other factors must also be considered when utilizing cleaning solvents, such as environmental regulations, safety concerns, and cost. [0003] Choline and other solvents have been utilized for a variety of processes in industry. These choline compositions have been used, for example, in the microprocessor industry, and the automotive industry. In these and other industries, there have been problems associated with the use of cholme compounds and choline derivative compounds.
• the base structures are made of silicon or quartzware (e.g. silicon dioxide).
• metal products such as copper, aluminum, gold, and silver.
• a photolithographic process is often used to construct the pattern on the microcircuit. This process utilizes photoresist materials on an insulating film or a conductive metal film (such as an oxide film, a copper film, or aluminum alloy film), coated on a substrate, to create the pattern on the microcircuit.
• a spin station is used to apply the photoresist on the surface ofthe wafer by dispensing the photoresist on the wafer.
• the spin station includes a member such as a spin chuck for holding and rotating the wafer and a spindle connected to a motor for rotating the spin chuck.
• the spin station also includes a catch cup and a dispensing member for applying the photoresist to the wafer.
• the spinning ofthe chuck quickly rotates the wafer, which spreads the photoresist across the surface ofthe wafer and rids the excess photoresist off the wafer.
• the final steps in preparing the substrate then involve removing the unexposed resist material and any etching residue, if etching was used, from the substrate. It is critical that all ofthe photoresist, flux and other debris and residue be removed to provide a wafer having sufficient integrity for subsequent use ofthe wafer in microcircuitry.
• plasma etching, reactive ion etching, or ion milling are also used to define the pattern in a substrate. During such etching processing, an organometallic by-product compound can be formed on the sidewall ofthe substrate material.
• a recently developed technique effective for photoresist removal is plasma oxidation, also known as plasma ashing.
• Polyimides are also used in microelectronics as fabrication aids, passivants, and inter-level insulators.
• the use of a polyimide as a fabrication aid includes application ofthe polyimide as a photoresist, planarization layer in a multi-level photoresist scheme and as an ion implant mask. In these applications, the polymer is applied to a wafer or substrate, subsequently cured or patterned by a suitable method and removed after use.
• cleaning the catch cups has been by removing the catch cup from the spin station and manually applied cleaning fluids to the contaminated inner surfaces of the catch cup.
• Another method of cleaning the catch cups involves a system having two rotating catch cups; one ofthe catch cups actively catches excess photoresist while a cleaning solvent is dispensed on the contaminated walls ofthe second catch cup.
• the solvents used in these processes often poses a safety concern, as they may be health or environmental hazards.
• the photoresist material was used to create interconnects made of aluminum or aluminum alloys isolated by dielectric material, for example silicon dioxide. More recently developed interconnects use copper as the conducting material and low-k dielectric material (a dielectric, having a dielectric constant, ⁇ , smaller than the dielectric constant of silicon dioxide).
• dielectric material for example silicon dioxide.
• the pattern is transferred from the photoresist through the dielectric. The gaps are then filled up by the conducting layer. This process is called damascene and can integrate either one level of interconnect only (single damascene) or both the horizontal interconnects and the vertical interconnects called vias (dual damascene).
• choline base can act as a etching agent of metal for thin film layer definition (Japanese Patent No. 62-281332 and U.S. Patent No. 4,172,005) and that adding choline atoms into an etching chamber when etching copper helps to lower the process temperature and hence minimize copper oxidation.
• U.S. Patent No. 5,846,695 discloses aqueous solutions of quaternary ammonium hydroxides, including choline, in combination with nucleophilic amines and sugar and/or sugar alcohols, for removal of photoresist and photoresist residues in integrated circuit fabrication.
• solder-flux from printed circuit boards is essentially one of washing the board with either an organic- solvent or water based cleaning solution.
• organic- solvent-systems that are imposed by environmental considerations
• water-based- systems are starting to dominate flux-removal processes. Whichever process is used, it is generally involves a dissolving/dilution/flushing process where the flux is dissolved and dispersed within the flushing-solvent through the action of one or more surface-active agents.
• Dual damascene structures have the advantage of incorporating both lines and vias in one deposition step; this reduces the number of process steps and is therefore cost effective.
• the main reason for the emergence of such structures nowadays is the fact that this is the easiest way to introduce copper.
• Variations ofthe dual damascene structure exist, incorporating a series of layers for process purposes such as anti-reflective coatings, adhesion promoters, moisture barriers, diffusion barriers, polishing stops, buried etch mask and so on.
• the choice of whether those have to be used or not and what material (SiO x N y or Si x N y ) should be used for them often depend upon the final choice ofthe low-k material.
• Known photoresist stripper compositions containing a combination of a polar solvent and an amine compound include: [0020] 1.
• U.S . Pat. No. 4,403,029 describes alkaline/solvent mixtures useful as photoresist strippers, but not necessarily cleaners, that include dimethylacetamide or dimethylformamide and alkanolamines.
• U.S. Pat. Nos. 4,428,871, 4,401,747, and 4,395,479 describe cleaners containing 2-pyrrolidone, dialkylsulfone and alkanolamines.
• 4,617,251 teaches a positive photoresist stripping composition containing (A) selected amine compound (e.g., 2-(2-aminoethoxy)-ethanol; 2-(2-aminoethylamino)-ethanol; and mixtures thereof) and (B) selected polar solvents (e.g., N-methyl-2-pyrolidinone, tetrahydrofurfuryl alcohol, isophorone, dimethyl sulfoxide, dimethyl adipate, dimethyl glutarate, sulfolane, gamma-butyrolactone, N,N-dimethylacetamide and mixtures thereof).
• selected amine compound e.g., 2-(2-aminoethoxy)-ethanol; 2-(2-aminoethylamino)-ethanol; and mixtures thereof
• selected polar solvents e.g., N-methyl-2-pyrolidinone, tetrahydrofurfuryl alcohol, isophorone, dimethyl sulfox
• U.S. Pat. No. 4,770,713 teaches a positive photoresist stripping composition containing (A) a selected amide (e.g., N,N-dimethyl acetamide; N-methyl acetamide; N,N-diethyl acetamide; N,N-dipropyl acetamide; N,N-dimethyl propionamide; N,N-diethyl butyramide and N-methyl-N-ethyl propionamide) and (B) selected amine compound (e.g., monoethanolamine, monopropanolamine, methyl-aminoethanol).
• A a selected amide
• this stripper may optionally contain a water miscible nonionic detergent (e.g., alkylene oxide condensates, amides and semi-polar nonionics).
• a water miscible nonionic detergent e.g., alkylene oxide condensates, amides and semi-polar nonionics.
• U.S. Pat. No. 4,824,763 teaches positive-working photoresist stripping composition containing (A) triamine (e.g., diethylene-triamine) and (B) a polar solvent (e.g. , N-methyl-2-pyrrolidone, dimethylformamide, butyrolactone, aliphatic hydrocarbons, aromatic hydrocarbons, chlorinated hydrocarbons).
• A triamine
• a polar solvent e.g. , N-methyl-2-pyrrolidone, dimethylformamide, butyrolactone, aliphatic hydrocarbons, aromatic hydrocarbons, chlorinated hydrocarbons.
• 4,904,571 teaches printed circuit board photoresist stripper composition containing (A) a solvent (e.g., water, alcohols, ethers, ketones, chlorinated hydrocarbons and aromatic hydrocarbons); (B) an alkaline compound dissolved in said solvent (e.g., primary amines, secondary amines, tertiary amines, cyclic amines, polyamines, quaternary ammonium amines, sulfoniumhydroxides, alkali hydroxides, alkali carbonates, alkali phosphates and alkali pyrophosphates); and (C) a borohydride compound dissolved in said solvent (e.g., sodium borohydride, lithium borohydride, dimethyl amine borone, trimethyl amine borone, pyridane borone, tert-butyl amine borone, triethyl amine borone, and morpholine borone).
• a solvent
• U.S. Pat. No. 5,102,777 teaches a positive photoresist stripper composition
• a solvent e.g., apyrrolidone compound, a diethylene glycol monoalkyl ether, a sulfur oxide compound, a sulfolane compound or a mixture thereof
• B an amine (e.g., alkanolamine)
• C a fatty acid (e.g., capric acid, lauric acid, talmitric acid, caprylic acid, myristic acid, oleic acid, stearic acid, linoleic acid, linolic acid, buthylic acid, abietic acid, isooctoic acid, isohexadecanoic acid, isostearic acid, behenic acid, undecylenic acid, hydroxystearic acid, chipanodonic acid, arachidonic acid, oleostearic acid, and 2-ethyl
• U.S. Pat. No. 5,279,791 teaches a stripping composition for removing resists from substrates containing (A) hydroxylamine; (B) at least one alkanolamine; and optionally (C) at least one polar solvent. [0029] 10.
• U.S. Pat. No. 5,279,791 teaches a stripping composition for removing resists from substrates containing (A) hydroxylamine; (B) at least one alkanolamine; and optionally (C) at least one polar solvent.
• an alkaline-containing photoresist stripping composition comprising (A) a stripping solvent (e.g., 2- ⁇ yrrolidinone, 1 -methyl-2-pyrrolidinone, 1 -ethyl-2-pyrrolidinone, 1 -propyl-2-pyrrolidinone, l-hydroxyethyl-2-pyrolidinone, l-hydroxypropyl-2-pyrrolidinone, diethylene glycol monoalkyl ethers, dialkyl sulfones, dimethyl sulfoxide, tetrahydrothiophene- 1,1 -dioxides, polyethylene glycol, dimethylacetamide and dimethylformamide; (B) a nucleophilic amine (e.g., l-amino-2-propanol, 2-(2-aminoethoxy) ethanol, 2-aminoethanol, 2-(2-aminoethylamino)-ethanol and 2-(2-aminoe
• U.S. Pat. No. 5,334,332 teaches a photoresist resist stripping and cleaning composition comprising (A) hydroxylamine; (B) at least one alkanolamine; (C) water; (D) optionally, at least one polar solvent; and (E) optionally, a chelating reagent (e.g., thiophenol, ethylenediamine tetraacetic acid and 1,2-dihydroxybenzene) to reduce the surface metal contamination on wafers.
• a chelating reagent e.g., thiophenol, ethylenediamine tetraacetic acid and 1,2-dihydroxybenzene
• 5,399,464 teaches a stripping composition for removing positive organic photoresist from a substrate comprising (A) a triarnine (e.g., diethylene triarnine); (B) a nonpolar or polar organic solvent (e.g., N-methyl pyrrolidone).
• A a triarnine
• B a nonpolar or polar organic solvent
• U.S. Pat. No. 5,417,802 teaches a material useful for photoresist removal or post-metal etch clean up that comprises (A) primary or secondary amines; (B) solvents (e.g., dimethyl sulphoxide or dimethylacetylamide); and (C) organic ligands such as crown ethers or cyclodextrines).
• JP Japanese Published Patent Application No.
• a positive- working photoresist stripper composition containing (A) a solvent (e.g., gamma-butyrolactone, N-methyl-formamide, N,N-dimethylformamide, N,N-dimethyl-acetamide or N-methylpyrrolidone); (B) an amino alcohol (e.g., N-butyl-ethanolamine and N-ethyldiethanolamine); and (C) water.
• A a solvent
• an amino alcohol e.g., N-butyl-ethanolamine and N-ethyldiethanolamine
• C water
• a stripper for positive photoresists comprising (A) l,3-dimethyl-2-imidazolidinone (DMT). (B) dimethylsulfoxide (DMSO) and (C) a water-soluble amine [e.g., monoethanolamine or 2-(2-amino-ethoxy)ethanol] wherein the amount ofthe water-soluble amine is 7-30% by weight. [0036] 17. Japanese Published Patent Application No. 1999-197523 describes a stripper composition for photoresist used in manufacture of liquid crystal display device that includes 5-15 weight % of alkanolamine, 35-55% sulfoxide or sulfone compound, and 35-55 wt.% glycol ether. [0037] 18.
• Japanese Published Patent Application No. 08087118 describes a stripper composition that includes 50-90 weight % of alkanolamine, and 50-10% dimethyl sulfoxide or N-methyl-2-pyrrolidone. [0038] 19. Japanese Published Patent Application No. 03227009 describes a stripper composition that includes ethanolamine and dimethyl sulfoxide. [0039] 20. Japanese Patent 07069619 describes a stripper composition that includes alkanolamine, dimethyl sulfoxide, and water. [0040] 21. U.S. Pat. No. 5,480,585 and the Japanese Patent Hei. 5-181753 disclose organic strippers comprising alkanolamine, sulfone compound or sulfoxide compound and a hydroxyl compound.
• the Japanese Laid-open Patent 4-124668 discloses a photoresist stripping composition including an organic amine of 20-90% by weight, phosphoric ester surfactant of 0.1-20% by weight, 2-butyne-l,4-diol of 0.1-20% by weight, and the remainder glycolmonoalkylether and/or aprotic polar solvent.
• 64-42653 discloses a photoresist stripping composition
• a photoresist stripping composition comprising over 50% by weight of dimethylsulfoxide (more desirably over 70% by weight), 1 to 50% by weight of a solvent selected among diethyleneglycolmonoalkylether, diethyleneglycoldialkylether, gamma-butyrolactone and l,3-dimethyl-2-imidazoledione, and 0.1 -5% by weight of nitrogen-including organic hydroxyl compound such as monoethanolamine. It states that the amount of dimethylsulfoxide less than 50% by weight causes great reduction in stripping force, while the amount of nitrogen-including organic hydroxyl compound solvent over 5% by weight corrodes the metal film such as aluminum.
• the aforementioned stripping compositions exhibit greatly different characteristics in photoresist stripping force, metal corrosion properties, the complexities of a rinsing process following the stripping, environmental safety, workability and price.
• Several commercial products are now available to clean the photoresist and plasma etching residues left by plasma etching followed by oxygen ashing.
• EKC 265TM available from EKC Technology, Inc., is a plasma etching cleaning solution composed of water, alkanolamine, catechol and hydroxylamine.
• Such a composition is disclosed in U.S. Pat. No. 5,279,771 to Lee.
• the alkanolamine used in the prior art cleaning compositions was often times found to attack both the plasma etching residues and the substrate metal layers in the presence of water.
• Water is often added as a contaminant, for example from the atmosphere, from wet components, and the like, and may even be released from certain photoresist structures during dissolution.
• the problem of water-cleaning composition induced corrosion has resulted in manufacturers resorting to alcohol or other solvent, for example isopropyl alcohol, to remove the cleaner.
• alcohol or other solvent for example isopropyl alcohol
• the stripping and cleaning compositions ofthe present invention remove photoresists without attacking the substrates themselves include metal substrates such as copper, aluminum, titanium/tungsten, aluminum/silicon, aluminum/silicon/copper; and substrates such as silicon oxide, silicon nitride, and gallium/arsenide, and plastic substrates such as polycarbonate.
• a cleaning or photoresist stripping composition including: (a) a polar aprotic organic solvent, preferably a cyclic nitrogen-containing compound, more preferably an N-alkyl-2-pyrrolidone (e.g., N-methyl-2-pyrolid(in)one), in an amount ranging from about 5 parts to about 50 parts, preferably from about 15 parts to about 35 parts, more preferably from about 20 parts to about 30 parts by weight, for example between about 24 parts and 26 parts; (b) a bis-choline and/or tris-choline salt in an amount ranging from about 0.2 parts to about 20 parts, preferably from about 0.5 parts to about 10 parts, more preferably between about 1 part and about 5 parts by weight, for example between about 2 parts and about 4 parts; and (c) a sulfoxide, preferably an alkylsulfoxide, more preferably comprising dimethyl sulfoxide, methyl sulfoxide, or a mixture thereof,
• a polar aprotic organic solvent
• the composition is substantially free of water. In another embodiment, the composition contains up to about 8 parts by weight of water. [0051] In still another embodiment, the composition is substantially free of one or more ofthe following: additional amines, additional corrosion inhibitors, additional chelating agents, additional surfactants, additional organic solvents, additional acids, and additional bases. In yet another embodiment, the composition is substantially free of all of the following: additional amines, additional corrosion inhibitors, additional chelating agents, additional surfactants, additional organic solvents, additional acids, and additional bases. In a further embodiment, the composition consists essentially ofthe three elements (a), (b), and (c) above.
• Photoresist or other polymeric materials such as polyimide
• Photoresist or other polymeric materials are often subjected to ion implantation, plasma etching, reactive ion etching or ion milling during the fabrication processes to define patterns in the substrate.
• oxygen plasma oxidation is often used for removal of photoresist or other polymeric materials after their use during the fabrication process has been completed.
• Such high energy processes typically result in the hardening ofthe photoresist and the formation of organometallic and other residues on sidewalls ofthe structures being formed in the fabrication process.
• a variety of metal and other layers are commonly employed in integrated circuit fabrication, including aluminum, aluminum/silicon/copper, titanium, titanium nitride, titanium/tungsten, tungsten, silicon oxide, polysilicon crystal, and the like.
• the use of such different layers results in the formation of different organometallic residues in the high energy processes.
• stripping and cleaning compositions should also not attack the different metallurgies used in integrated circuit fabrication.
• a photoresist stripping composition should have a high photoresist dissolving and stripping force, and should maintain a stripping force for various kinds of substrates.
• the composition should have good chemical properties, such as stripping force, non-corrosiveness of metal and safety of humans, and prevent photoresist residues or impurities from remaining on the substrate.
• the method of cleaning a substrate using the cleaning compositions ofthe present invention involves contacting a substrate having residues and/or flux thereon with a cleaning composition ofthe present invention for a time and at a temperature sufficient to remove the residue. Stirring, agitation, circulation, sonication or other techniques as are known in the art optionally may be used.
• the substrate is generally immersed in the cleaning composition. The time and temperature are determined based on the particular material being removed from a substrate.
• the temperature is in the range of from about 10°C, to about 100°C, preferably from 15°C to about 75°C, most preferably from about 20°C to about 55°C.
• the contact time is from about 1 to about 60 minutes, preferably about 5 to about 30 minutes.
• the substrate will be rinsed after using the composition. While the rinse composition may vary based on the cleaning composition and on the substrate, ter alia, preferred rinse solutions include isopropanol and/or deionized water.
• the compositions ofthe invention are particularly useful for removing residue and flux from metals and via features but are also useful for stripping photoresists. The application ofthe present compositions as a photoresist stripper is easily determined by one of skill in the art.
• the present invention provides the photoresist stripping composition that meets above-described conditions by increasing the amounts of a polar solvent and an amine compound.
• the photoresist stripping composition includes a choline compound, a solvent, and optional stabilizers, chelators, and the like.
• the invention also relates to a non-corrosive stripper useful for many combinations of metals and dielectric compounds.
• the formulations are especially useful on copper (e.g., PVD or electroplate) and low-k dielectrics (e.g., Coral), also on aluminum, TEOS, solder bumps, and the like.
• the composition is particularly useful with copper substrates, as it does not encourage copper corrosion.
• the invention also relates generally to manufacture of semiconductor devices incorporating a metal interconnect. More specifically, it relates to a composition and process to clean post etch residues at an ( interconnect level, such as with a copper metallurgy, preferably incorporating a damascene/dual damascene structure. The invention further relates to a composition for other post etch residue-cleaning applications, such as aluminum, or aluminum alloy interconnects with misaligned tungsten plugs. [0061] A key challenge in reduced geometry devices, such as in 0.18 ⁇ m technology, is the interconnect RC delay time, which becomes the limiting factor ofthe device performance.
• This delay can be improved by combining low dielectric constant between tracks and the use of copper as a better conductor.
• This application is directed to solving some ofthe difficulties in integrating this type of interconnects, and a new strategy for the post dielectric etch cleaning process.
• the development of new cleaning chemistries and processes for their use, which are compatible with copper and low-k dielectric materials, is essential for process integration.
• copper can not easily be dry etched, the use of damascene or dual damascene structures is becoming a key solution to realize this integration. With the appearance of new materials such as organic polymers for inter metal dielectric material, and the need to etch complex layers of dielectric materials, photoresist removal and cleaning steps can benefit from a new strategic approach.
• the composition includes an amount of a bis-choline compound, a tris-choline compound, or a combination thereof, and a solvent. Further, each of these compositions may include several optional ingredients.
• the choline compositions ofthe present invention contain from about 1 to about 70 weight %, preferably about 5 to about 50 weight %, most preferably about 10 to about 30 weight %, ofthe choline compound.
• the choline compounds can be bis-choline compounds (bis-(2-hy ⁇ j ⁇ oxy-ethyl)-dimethyl-ammonium ion); tris- choline (tris-(2-hydroxy-ethyl)-methyl-ammonium ion) compounds; or a combination thereof.
• the choline compound in the hydroxide or salt form, including, but not limited to, tris-choline hydroxide, bis-choline hydroxide, tris-choline bicarbonate, bis-choline bicarbonate, tris-choline chloride, or bis- choline chloride.
• the choline compound is bis-choline hydroxide and/or tris- choline hydroxide.
• the formation ofthe choline compounds can be by any production method known to one of ordinary skill in the art. Typical methods include reacting trimethylamine and ethylene chlorohydrin or ethylene oxide as taught by U.S. Patent No.
• bis-choline or tris-choline is advantageously used in the compounds of this invention. Without wishing to be bound by theory, it is believed that bis-choline compounds show reduced efficacy in etching quartzwares while tris-choline compounds do not substantially etch quartzwares because ofthe addition of hydroxyethyl groups to the central nitrogen. It is believed that this addition sterically hinders the molecule, making it increasingly less reactive as these groups are added without substantially affecting its solvent properties.
• the solvents used in the compositions and for practice ofthe processes should have a good solubility for cross-linked resist films, flux materials, and other debris that may be present. The solvent is necessary to efficiently remove these materials which are strongly adhering to the substrate. At the same time, the composition should not promote corrosion ofthe substrate.
• the composition is useful for most metal-dielectric combinations, including one or more of copper, aluminum, tungsten, titanium, chromium, or the like for metals; and one or more of HSQ, SiLKTM, SiOC, NanoglassTM, HOSPTM, CoralTM, GaAs, TEOS, or the like for low-K materials.
• the claimed composition is particularly useful on copper, and also on aluminum, TEOS, solder bumps, and the like. Because of its inability to create a passivation layer, traditional cleaning solvents are not well suited to work with copper, as they usually contain aggressive complexing agents.
• Suitable organic solvents in the compositions and for practice ofthe processes can include any solvent known to one skilled in the art.
• the compositions include polar solvents having a dipole moment more than about 3.5, a boiling point of more than about 130°C, or a combination thereof.
• polar solvents of this invention include, but are not limited to, dimethyl sulfoxide, ethylene glycol, ethylene glycol alkyl ether, diethylene glycol alkyl ether, triethylene glycol alkyl ether, propylene glycol, propylene glycol alkyl ether, N-substituted pyrrolidone, ethylene diamine, and ethylene triamine.
• Preferred solvents for this invention include nitrogen- containing compounds.
• N-alkyl-2-pyrolidones e.g., N-methyl-2-pyrolid(in)one, N-hydroxyethyl-2-pyrrolidone, or a mixture thereof.
• the solvent is N-methylpyrrolidone.
• N-methylpyrrolidone is a strong solvent for dissolving the photoresist.
• the amount ofthe N-methylpyrrohdone is preferably about 30 to about 50 weight %, and more preferably about 35 to about 45 weight %, based on the total amount ofthe stripping composition.
• the stripping force ofthe composition is not reduced even when the stripping processes are repeated.
• the cyclic nitrogen- containing solvents are present in an amount ranging from about 5% to about 50%, preferably from about 15% to about 35%, more preferably from about 20% to about 30% by weight, and most preferably from about 20% to about 28%.
• additional performance chemicals for example, surfactants, chelating agents, corrosion inhibitors, and the like, can be added.
• the total concentration of these performance chemicals is below about 20% by weight, more preferably below about 10% by weight.
• the composition is substantially free from one or more of: additional surfactants, additional chelating agents, and additional corrosion inhibitors.
• An optional component of this invention is an additional amine.
• Suitable additional amine compounds include, but are not limited to, the following and mixtures thereof: hydroxylamine, hydrazine, 2-amino-2-ethoxy ethanol (DGA), monoethanolamine (MEA), diethylhydroxylamine, 2-methylamine ethanol, monomethylethanolamine, cholines, tetramethylammonium formate (TMAF), monoisopropanolamine (ML?
• exemplary compounds include monoethanolamine, 2-(2-aminoethoxy)ethanol, diethanolamine, triethanolamine, and 2-(2-aminoethylamino)ethanol, or any combination thereof.
• the amine when present, can appear in an amount ranging from about 0.2% to about 20%, preferably from about 0.5% to about 10%, more preferably between about 2% and about 5% by weight. If the amount of alknolamine is less than 0.2 weight %, the stripping force ofthe composition can sometimes become reduced, and in these cases, impurities can be left over on the substrate. If used in an amount more than 20% by weight, an alkanolamine can degrade the composition's characteristic of being absorbed into the layers, which can increase the contact angle ofthe composition with the layers and may reduce the photoresist's stripping capabilities.
• an alkanolamine such as monomethylethanolamine (2-methylamino-ethanol
• composition can be substantially free from additional amines.
• additional sulfoxide and/or sulfone solvents can include one or more ofthe following: dimethyl sulfoxide (DMSO), methyl sulfoxide, dipropylsulfoxide, diethylsulfoxide, methylethylsulfoxide, diphenylsulfoxide, methylphenylsulfoxide, diethylsulfone, dimethylsulfone, l,l'-dihydroxyphenyl sulfoxide, a sulfoxide having the formula
• R 3 - R 10 are independently H or an alkyl group, or the like, or a mixture thereof.
• the sulfoxide or sulfone preferably an alkylsulfoxide, more preferably dimethyl sulfoxide, methyl sulfoxide, or a mixture thereof, can be present in an amount ranging from about 50% to about 94%, more preferably from about 60% to about 84%, more preferably between about 66% to about 76% by weight.
• the sulfoxide or sulfone controls the surface tension between the surface ofthe photoresist and the stripping composition.
• the amount ofthe sulfoxide or sulfone is preferably about 10 to about 35 weight %, and more preferably about 15 to about 30 weight %, based on the total amount ofthe stripping composition.
• the composition can be substantially free from additional sulfoxide and/or sulfone solvents.
• a corrosion inhibitor may be included in a formulation used to clean structures with exposed copper present. If present, the corrosion inhibitor is typically provided in an amount from about 0.1 to about 10 weight %, alternately from about 0.5 to about 5 weight %.
• the corrosion inhibitors are present to protect copper from being corroded, and maybe chosen from a variety of classes of chemical compounds, including any compounds used for the prevention of copper corrosion in other systems comprising the art.
• pendant R groups R,-R 5 maybe chosen independently as H, optionally a substituted C,-C 6 straight, branched or cyclo alkyl, alkenyl or alkynyl group, straight or branched alkoxy group, optionally a substituted acyl group, straight or branched alkoxy group, amidyl group, hydroxyl group, a halogen, carboxyl group, alkoxyalkyl group, alkylamino group, alkylsulfonyl group or sulfonic acid group; or the salt of such compounds.
• X, Y and Z are nitrogen, nitrogen and carbon, respectively, and R j -R 5 are hydrogen.
• X, Y and Z are nitrogen, R 3 is hydrogen and R 4 and R 5 constitute a benzene ring.
• Another class of copper corrosion inhibitors, the hydroxybenzenes maybe employed in the invention independently or in conjunction with the classes already cited herein. These comprise the general class having the following formula:
• n l-4, and wherein Rg may be present from 1-5 times and may be chosen independently as H, optionally a substituted C r C 6 straight, branched or cyclo alkyl, alkenyl or alkynyl group, straight or branched alkoxy group, optionally a substituted acyl group, straight or branched alkoxy group, amidyl group, a halogen, carboxyl group, alkoxyalkyl group, alkylamino group, alkylsulfonyl group or sulfonic acid group, or the salt of such compounds.
• Suitable specific examples of such corrosion inhibitors include catechol, t-butyl catechol, and the like, and combinations thereof.
• Another class of copper corrosion inhibitors includes inorganic salts and other corrosion inhibitors.
• Suitable inorganic salts include, but are not limited to nitrate salts such as ammonium, potassium, sodium and rubidium nitrate salts, aluminum nitrate and zinc nitrate.
• Other suitable corrosion inhibitors include, but are not limited to, benzotriazole, pyrogallol, gallic acid, and combinations thereof.
• the composition can optionally contain hydroxylamine or a hydroxylamine salt, such as a nitrate, phosphate, sulfate, carbonate, or the like. If present, the composition desirably contains from about 0.2 to about 12% by weight ofthe hydroxylamine or hydroxylamine salt.
• chelating agents and/or surfactants may be added to the compositions of this invention. Suitable chelating agents are described in commonly assigned U.S. Patent 5,672,577, issued September 30, 1997 to Lee, which is incorporated herein by reference. The addition of a chelator further improves the effectiveness ofthe formulation used as a etch residue or photoresist remover. If present, the composition desirably contains from about 0.2 to about 12% by weight ofthe chelating agent.
• Suitable surfactants include poly(vinyl alcohol), poly(ethyleneimine) and any ofthe surfactant compositions classified as anionic, cationic, nonionic, amphoteric, and silicone based.
• Preferred surfactants are poly(vinyl alcohol) and poly(ethyleneimine). If present, the composition desirably contains from about 0.01 to about 5 weight % ofthe surfactant. [0079] Some combinations of components require the addition of acids and/or bases to adjust the pH to an acceptable value.
• the acids suitable for use in the present invention are organic or inorganic.
• the acids can include nitric, sulfuric, phosphoric, hydrochloric acids (though hydrochloric acid can be corrosive to metals) and the organic acids, formic, acetic, propionic, n-butyric, isobutyric, benzoic, ascorbic, gluconic, malic, malonic, glycolic, oxalic, succinic, tartaric, citric, and gallic.
• the caustic components suitable for use to adjust the pH ofthe cleaning solution can be composed of any common base, e.g., sodium, potassium, magnesium hydroxides, or the like. The major problem is that these bases introduce mobile ions into the final formulation. Mobile ions could destroy computer chips being produced today in the semiconductor industry.
• compositions can be substantially free from additional acids.
• composition can be substantially free from additional bases.
• composition can be substantially free from both additional acids and additional bases.
• the composition can preferably be water-free, but in some embodiments may contain some water, preferably less than about 10%, more preferably less than about 5%, more preferably less than about 1%.
• the stripper/cleaner composition contains the following: [0084] (a) a polar aprotic organic solvent, preferably a cyclic nitrogen-containing compound, more preferably an N-alkyl-2-pyrrolidone (e.g., N-methyl-2-pyrolid(in)one), in an amount ranging from about 5% to about 50%, preferably from about 15% to about 35%, more preferably from about 20% to about 30% by weight, for example between about 24% and 26%; [0085] (b) a bis-choline and/or tris-choline salt in an amount ranging from about 0.2% to about 20%, preferably from about 0.5% to about 10%, more preferably between about 1% and about 5% by weight, for example between about 1% and about 3%; and [0086] (c) a sulfoxide, preferably an alkylsulfoxide, more preferably comprising dimethyl sulfoxide, methyl sulfoxide, or a mixture thereof,
• the stripper/cleaner composition consists essentially ofthe following three components: [0088 (a) a polar aprotic organic solvent having a dipole moment of more than 3.5, preferably a cyclic nitrogen-containing compound, more preferably an N-alkyl- 2-pyrrolidone (e.g., N-methyl-2-pyrrolid(in)one), in an amount ranging from about 5% to about 50%, preferably from about 15% to about 35%, more preferably from about 20% to about 30% by weight, for example between about 24% and 26%; [0089] (b) bis-choline and/or tris-choline in an amount ranging from about 0.2% to about 20%, preferably from about 0.5% to about 10%, more preferably between about 1% and about 5% by weight, for example between about 1% and about 3%; and [0090] (c) a sulfoxide, preferably an alkylsulfoxide, more preferably comprising dimethyl sulfoxide, methyl
• Example 1 Compositions using choline derivatives as a stripper for photoresist on wafers.
• Example 1 is a composition that can be used for applying choline derivatives as a stripper for a liquid photoresist on wafers.
• Example 2 Compositions using choline derivatives as a stripper for dry film photoresist on printed circuit boards.
• Example 2 is a composition that can be used for applying choline derivatives as a stripper for a dry film photoresist on a printed circuit board.
• Example 3 Compositions using choline derivatives as a developer of a photoresist film.
• Example 3 is a composition that can be used for applying choline derivatives as a developer of a photoresist film.
• Example 4 An alternate composition using choline derivatives as a stripper for a dry film photoresist on printed circuit boards.
• Example 4 is a composition that can be used for applying choline derivatives as a copper-compatible stripper for a dry film photoresist.
• Example 5 A preferred composition that can be used as a cleaner for quartzware or alternately as a stripper/remover for photoresists on circuit boards.

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