WO2007027522A2

WO2007027522A2 - Composition and method for removing thick film photoresist

Info

Publication number: WO2007027522A2
Application number: PCT/US2006/033237
Authority: WO
Inventors: David D. Bernhard; Melissa K. Rath
Original assignee: Advanced Technology Materials, Inc.
Priority date: 2005-08-29
Filing date: 2006-08-25
Publication date: 2007-03-08
Also published as: WO2007027522A3; TW200718775A

Abstract

A thick film photoresist and/or residue removal composition and process for removing thick film photoresist and/or post-ash and post-etch residue from a microelectronic assembly having same thereon. The removal composition includes at least one organic acid, at least one organic solvent, and water. The composition achieves at least partial removal of thick film photoresist and residue from the surface of the microelectronic assembly with minimal etching of metal species on the assembly and without damage to low-k dielectric materials employed in the assembly architecture.

Description

COMPOSITION AND METHOD FOR REMOVING THICK FILM PHOTORESIST

FIELD OF THE INVENTION

[0001] The present invention relates to a composition and method for removing thick film photoresist and/or post-ash and post-etch residue from microelectronic assemblies, wherein the removal compositions have a high selectivity for the thick film photoresist and/or residue without damaging low-k dielectric material or corroding metallic materials on the microelectronic assembly.

DESCRIPTION OFTHERELATED ART

[0002] With the downsizing of electronic equipment, there has been an increased demand for multipin thin-film packaging for mounting Large Scale Integrations (LSIs) on electronic equipment, specifically bare chip packaging carried out by the Tape Automated Bonding (TAB) system or flip- chip system. In such multipin packaging, protruded electrodes of 20 μm or more in height, called bumps, serve as connecting terminals and must be arranged on the substrate in a highly precise fashion.

[0003] In addition to the formation of the connecting terminals, a rewiring process is often performed to form wiring between the chip and the connecting terminals. In this procedure, the wiring is patterned with the use of a resist film about 5 to about 20 μm in thickness.

[0004] Thick film photoresists are used in the process of forming such bumps, rewiring or metal posts. The term "thick film photoresist" as used herein includes resist films having a thickness in a range from about 5 μm to 100 μm. An example of a thick film photoresist used in the art includes poly(hydroxystyrene) polymer with a melamine cross-linker.

[0005] The thick-film photoresists must satisfy various requirements. For example, they must be capable of forming a film having a thickness of from about 5 μm to 100 μm, must adhere to the substrates, must display a high aspect ratio upon development, must be resistant and display good wettability to the plating solution, must permit the formation of a metallic structure corresponding to the shape of the resist pattern, and must be easily removed after plating. Thick film photoresists also should be resistant to the plating process itself, since many plating procedures are repeated or the plating process is performed under severe conditions. Further, the thick film photoresist must be suitable for photofabrication processes including, but not limited to, bump formation, wiring, metal post formation, interlayer insulating film formation, and circuit protective film formation. [0006] After pattern transfer and electroplating, the thick film photoresist layer must be cleanly removed from the microelectronic assembly in order to obtain defect-free metal structures, e.g., bumps, rewiring and metal posts. If not removed, the photoresist may interfere with subsequent packaging processes.

[0007] Typically, photoresist is removed by oxidative or reductive plasma ashing or wet cleaning. Ashing is often preferred for photoresist removal because the process is carried out under vacuum conditions and as such, is less susceptible to contamination. However, post-ash residues may be formed which may lead to device failure, so it is often necessary to perform a post-ash cleaning step using liquid cleaners.

[0008] The integration of new materials, such as low-k dielectrics, into microelectronic assemblies places new demands on cleaning performance. At the same time, shrinking device dimensions reduce the tolerance for changes in critical dimensions and damage to device elements. Etching and ashing conditions can be modified in order to meet the demands of the new materials. Likewise, removal compositions must be modified. Importantly, the removal composition should not damage the underlying low-k dielectric material, substantially corrode metallic materials, e.g., copper and/or cobalt, on the assembly, have high silicon nitride etch rates, and must have a wide process window to allow for greater variation in the process.

[0009] Towards that end, it is an object of the present invention to provide improved removal compositions for the effective removal of thick film photoresist and/or post-etch/post-ash residues from microelectronic assemblies, especially from low-k dielectric-containing assemblies.

SUMMARY OF THE INVENTION [0010] The present invention relates generally to a removal composition and process for the removal of thick film photoresist and/or post-ash and post-etch residue from microelectronic assemblies having same thereon. The removal composition includes organic acid(s), organic solvent(s), and water.

[0011] In one aspect, the invention relates to a thick film photoresist removal composition, comprising at least one organic acid, at least one organic solvent, and water, wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition, and wherein said removal composition is suitable for removing thick film photoresist from a microelectronic assembly having said material thereon.

[0012] In another aspect, the invention relates to a thic₍k film photoresist removal composition, consisting essentially of at least one organic acid, at least one organic solvent, and water, wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition, and wherein said removal composition is suitable for removing thick film photoresist from a microelectronic assembly having said material thereon.

[0013] In another aspect, the invention relates to a kit comprising, in one or more containers, thick film photoresist removal composition reagents, wherein said removal composition comprises at least one organic acid, at least one organic solvent, and water, wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition, and wherein the kit is adapted to form the removal composition suitable for removing thick film photoresist from a microelectronic assembly having said material(s) thereon.

[0014] Yet another aspect of the invention relates to a method of removing thick film photoresist from a microelectronic assembly having said material thereon, said method comprising contacting the microelectronic assembly with a removal composition for sufficient time to at least partially remove said photoresist from the microelectronic assembly, wherein the removal composition includes at least one organic acid, at least one organic solvent, and water, and wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition. [0015] Another aspect of the invention relates to thick film photoresist removal composition, comprising at least one organic acid, water, and at least two organic solvents selected from the group consisting of di(ethylene glycol) methyl ether, tetramethylene sulfone, NMP, and combinations thereof, wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition, and wherein said removal composition is suitable for removing thick film photoresist from a microelectronic assembly having said material thereon. [0016] A still further aspect of the invention relates to a thick film photoresist removal composition, comprising at least one organic acid, water, and at least one organic solvent, wherein said removal composition is suitable for removing thick film photoresist from a microelectronic assembly having said material thereon, and wherein said removal composition is devoid of at least one species selected from the group consisting of a fluorine source, an amine source, a silazane source, an inorganic acid, oxidizing agent, and a silane compound source, and wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition.

[0017] Yet another aspect of the invention relates to improved microelectronic assemblies, and products incorporating the same, made using the methods of the invention comprising contacting the microelectronic assembly with a removal composition for sufficient time to at least partially remove thick film photoresist and/or post-ash and post-etch residue from the microelectronic assembly having same thereon, wherein the removal composition includes at least one organic acid, at least one organic solvent, and water and wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition. [0018] Yet another aspect of the invention relates to improved microelectronic assemblies, and products incorporating the same, made using the methods of the invention comprising at least partial removal of thick film photoresist and/or post-ash and post-etch residue from the microelectronic assembly having same thereon, using the methods and/or compositions described herein, and optionally, incorporating the microelectronic assembly into a product.

[0019] Other aspects, features and embodiments of the invention will be more fully apparent from the ensuing disclosure and appended claims.

DETAILED DESCRIPTION OF THE INVENTION, AJVD PREFERRED EMBODIMENTS THEREOF

[0020] The present invention relates to removal compositions that remove thick film photoresist and/or post-ash and post-etch residue from a microelectronic assembly having such material(s) thereon, said compositions having high selectivity for the thick film photoresist and residue material thereby minimizing damage to underlying low-k dielectrics and metallic bump and post materials, e.g., copper and cobalt.

[0021] For ease of reference, "microelectronic assembly" corresponds to resist-coated semiconductor and advanced packaging substrates including flip chip components. The flip chip components used in flip chip microelectronic assemblies are predominantly semiconductor devices, however, components such as passive filters, detector arrays, and MEMS devices are also being used in flip chip form. Flip chips are also known as "direct chip attach" because the chip is directly attached to the substrate, board, or carrier by the conductive bumps. It is to be understood that the term "microelectronic assembly" is not meant to be limiting in any way and includes any substrate that will eventually become a microelectronic assembly.

[0022] "Photoresist," as used herein, refers to undeveloped, developed, ion-implanted or hard baked photoresist.

[0023] "Post-etch residue," as used herein, corresponds to material remaining following gas-phase plasma etching processes, e.g., BEOL dual damascene processing. The post-etch residue may be organic, organometallic, organosilicic, or inorganic in nature, for example, silicon-containing material, carbon-based organic material, and etch gas residue such as chlorine and fluorine. [0024] "Post-ash residue," as used herein, corresponds to material remaining following oxidative or reductive plasma ashing to remove hardened photoresist and/or bottom anti-reflective coating (BARC) materials. The post-ash residue may be organic, organometallic, organosilicic, or inorganic in nature.

[0025] As defined herein, "low-k dielectric material" corresponds to any material used as a dielectric material in a layered microelectronic device, wherein the material has a dielectric constant less than about 3.5. Preferably, the low-k dielectric materials include low-polarity materials such as silicon- containing organic polymers, silicon-containing hybrid organic/inorganic materials, organosilicate glass (OSG), TEOS, fluorinated silicate glass (FSG), silicon dioxide, and carbon-doped oxide (CDO) glass. It is to be appreciated that the low-k dielectric materials may have varying densities and varying porosities.

[0026] As used herein, "about" is intended to correspond to ± 5 % of the stated value. [0027] As used herein, "suitability" for removing thick film photoresist and/or post-ash and post-etch residue from a microelectronic assembly having such material(s) thereon corresponds to at least partial removal of such material(s) from the microelectronic assembly. Preferably, at least about 90 % of the material(s), more preferably at least 95% of the material(s), and most preferably at least 99% of the material(s), are removed from the microelectronic device using the compositions of the invention. [0028] Presently, the process of forming metallic bumps or posts on the surface of a process article that will become a microelectronic assembly includes the coating of a thick film photosensitive resin composition on the surface of a process article (e.g., using spin-on coating), patterning and developing the coating film using photolithographic techniques, hard baking the developed thick film on the process article, electroplating the patterned photoresist with the desired metal, and removing the thick film photoresist. The removal of thick film photoresist presents a unique challenge relative to the removal of conventional positive and negative photoresist materials. [0029] Importantly, the removal compositions of the present invention must possess good metal compatibility, e.g., a low etch rate on the metal. Metals of interest include, but are not limited to, copper, tungsten, cobalt, cobalt tungsten phosphorous (CoWP), aluminum, tantalum, ruthenium, and relevant suicides thereof.

[0030] Compositions of the invention may be embodied in a wide variety of specific formulations, as hereinafter more fully described.

[0031] In all such compositions, wherein specific components of the composition are discussed in reference to weight percentage ranges including a zero lower limit, it will be understood that such components may be present or absent in various specific embodiments of the composition, and that in instances where such components are present, they may be present at concentrations as low as 0.001 weight percent, based on the total weight of the composition in which such components are employed. [0032] In one aspect, the present invention relates to a removal composition for removing thick film photoresist and post-ash and post-etch residue from the surface of a microelectronic assembly having same thereon, said composition including at least one organic acid, at least one organic solvent, water, optionally at least one chelating agent, optionally at least one surfactant and optionally buffer(s), present in the following ranges, based on the total weight of the composition. component % by weight organic acid(s) about 1 to about 25 % organic solvent(s) about 5 to about 95% water about 1 to about 50% chelating agent(s) O to about 10% surfactant(s) O to about 10% buffer(s) O to about 10%

[0033] The removal compositions of the invention effectively remove essentially all thick film photoresist from the surface of the microelectronic assembly without causing damage to low-k dielectric material and without causing substantial corrosion of the metal bumps, posts or rewiring. [0034] In another embodiment, the invention relates to a removal composition for removing thick film photoresist and post-ash and post-etch residue from the surface of a microelectronic assembly having same thereon, said composition including at least one organic acid, at least one organic solvent, water, and optionally buffer(s), wherein said removal composition is substantially devoid of at least one species selected from the group consisting of a fluorine source, an amine source, an inorganic acid, oxidizing agent, a silazane source, and a silane compound source. In a particularly preferred embodiment, the removal composition includes less than about 30 wt. % water and weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition. As defined herein, "substantially devoid" corresponds to less than about 0.5 wt. %, more preferably less than 0.05 wt. %, and most preferably less than 0.005 wt. % of the composition, based on the total weight of said composition.

[0035] In the broad practice of the invention, the removal composition may comprise, consist of, or consist essentially of at least one organic acid, at least one organic solvent, water, optionally at least one chelating agent, optionally at least one surfactant and optionally buffer(s). In general, the specific proportions and amounts of organic acid(s), organic solvent(s), water, optional chelating agent(s), optional surfactant(s) and optional buffer(s), in relation to each other, may be suitably varied to provide the desired removal action of the removal composition for the thick film photoresist, residue and/or processing equipment, as readily determinable within the skill of the art without undue effort. The water is preferably deionized.

[0036] The range of mole ratios for organic solvent(s) relative to organic acid(s) is about 1:1 to about 60:1, preferably about 5:1 to about 40:1, even more preferably about 9:1 to about 30:1, and most preferably about 12:1 to about 16:1; and the range of mole ratios for organic solvent(s) relative to water is about 1:20 to about 20:1, preferably about 1:10 to about 10:1, even more preferably about 1:3 to about 3:1, and most preferably about 5:10 to about 6:10.

[0037] It is to be understood that the phrase "removing thick film photoresist from the surface of a microelectronic assembly" is not meant to be limiting in any way and includes the removal of thick film photoresist from any substrate or surface that will eventually become a microelectronic assembly or during the manufacture of giant magneto-resistive (GMR) read write heads.

[0038] It is also contemplated herein that the removal composition may be used to remove post-ash and post-etch residue from the surface of a microelectronic assembly having same thereon. [0039] Compositions of the invention have a pH value in a range from about 0 to about 6, preferably about 1 to about 3. In addition, the compositions of the invention have a density in a range from about 1 g cm^"3 to about 1.1 g cm^"3, more preferably about 1.02 g cm^"3 to about 1.08 g cm^"3 at ambient temperature and pressure.

[0040] Although not wishing to be bound by theory, it is thought that the organic acid works by cleaving the cross-links in the thick film photoresist material in a catalytic fashion. Suitable organic acid species include, but are not limited to, lactic acid, maleic acid, ascorbic acid, malic acid, benzoic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, mandelic acid, maleic anhydride, citric acid, phthalic acid, other aliphatic and aromatic carboxylic acids, as well as combinations of the foregoing acids. Preferably, the organic acid is maleic acid. In a particularly preferred embodiment, the organic acid is not ozonated and present in an amount greater than 1 wt. %, more preferably greater than about 2 wt. %, based on the total weight of the composition.

[0041] Suitable solvent species for such composition include, without limitation amines, ethers, ketones, keto-pyrroles, sulfur-containing solvents, glycols, and glycol ethers such as acetone, 2- butanone, 2-pentanone, 3-pentanone, tetrahydrofuran, monoethanolamine, triethanolamine, triethylenediamine, methylethanolamine, methyldiethanolamine, pentamethyldiethylenetriamine, dimethyldiglycolamine, 1 ,8-diazabicyclo[5.4.0]undecene, aminopropylmorpholine, hydroxyethylmorpholine, aminoethylmorpholine, hydroxypropylmorpholine, diglycolamine, N- methylpyrrolidinone (NMP), N-octylpyrrolidinone, N-phenylpyrrolidinone, cyclohexylpyrrolidinone, vinyl pyrrolidinone, tetramethylene sulfone, methyl sulfoxide, ethylene glycol, propylene glycol (1,2- propanediol), neopentyl glycol, benzyl diethylene glycol (BzDG), diethylene glycol monomethyl ether, Methylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monopropyi ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol phenyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether (phenoxy-2-propanol) and combinations thereof. Preferably, the solvent species include di(ethylene glycol) methyl ether, tetramethylene sulfone, NMP, and combinations thereof.

[0042] Suitable surfactant species for such composition include, without limitation: fluoroalkyl surfactants; polyethylene glycols; polypropylene glycols; polyethylene glycol ethers; polypropylene glycol ethers; carboxylic acid salts; dodecylbenzenesulfonic acid and salts thereof; polyacrylate polymers; dinonylphenyl polyoxyethylene; silicone polymers; modified silicone polymers; acetylenic diols; modified acetylenic diols, alkylammonium salts; modified alkylarnmonmm salts; alkylammonium suflonic acid inner salts and combinations of two or more of the foregoing. [0043] The chelating agent(s) may be added to reduce the attack on the metals, e.g., copper and/or cobalt, in the underlying layers. The chelator/passivation agent in such composition may be of any suitable type, and may include, without limitation, triazoles, such as 1,2,4-triazole, or triazoles substituted with substituents such as C₁-C₈ alkyl, amino, thiol, mercapto, imino, carboxy and nitro groups, such as benzotriazole, tolyltriazole, 5-phenyl-benzotriazole, 5-nitro-benzotriazole, 3-amino~5- mercapto- 1,2,4-triazole, l-amino-l,2,4-triazole, hydroxybenzotriazole, 2-(5-amino-pentyl)- benzotriazole, l-amino-l,2,3-triazole, l-ammo-5-methyl-l,2,3-triazole, 3-amino-l,2,4-triazole, 3- mercapto-1 ,2,4-triazole, 3-isopropyl-l ,2,4-triazole, 5-phenylthiol-benzotriazole, halo-benzotriazoles (halo = F, Cl, Br or I), naphthotriazole, and the like, as well as thiazoles, tetrazoles, imidazoles, phosphates, thiols and azines such as 2-mercaptobenzoimidizole, 2-mercaptobenzothiazole, 4-methyl- 2-phenylimidazole, 2-mercaptothiazoline, 5-aminotetrazole, 5-amino-l,3,4-thiadiazole-2-thiol, 2,4- diamino-6-methyl-l,3,5-triazine, thiazole, triazine, methyltetrazole, 1 ,3-dimethyl-2-imidazolidinone, 1 ,5-pentamethylenetetrazole, 1 -phenyl-5-mercaptotetrazole, diaminomethyltriazine, mercaptobenzothiazole, imidazoline thione, mercaptobenzimidazole, 4-methyl-4H-l,2,4-triazole-3- thiol, 5-amino-l,3,4-thiadiazole-2-thiol, benzothiazole, tritolyl phosphate, indiazole, etc. Suitable chelator species further include glycerols, amino acids, carboxylic acids, alcohols, amides and quinolines such as guanine, adenine, glycerol, thioglycerol, nitrilotriacetic acid, salicylamide, iminodiacetic acid, benzoguanamine, melamine, thiocyranuric acid, anthranilic acid, gallic acid; ascorbic acid; salicylic acid; 8-hydroxyquinoline, 5-carboxylic acid-benzotriazole, 3- mercaptopropanol, boric acid, iminodiacetic acid, etc. The chelator is usefully employed to increase the compatibility of the composition with the metals and the dielectric materials used in the microelectronic device.

[0044] The acid/base buffer serves to stabilize the pH and control the etch rate selectivity of the solution to other residues, as well as permanent materials such as dielectrics and interconnect metals.

Species useful in the buffering system of the instant invention include, but are not limited to: formic acid, trifluoroacetic acid, propionic acid, butyric acid, valeric acid, heptanoic acid, lactic acid, oxalic acid, malic acid, malonic acid, succinic acid, fumaric acid, adiptic acid, benzoic acid, phtalic acid, citric acid, and salts thereof.

[0045] Such compositions may optionally include additional components, including active as well as inactive ingredients, e.g., stabilizers, passivators, dispersants, etchants, anti-oxidants, and other additives known to those skilled in the art.

[0046] In a particularly preferred embodiment of the present invention, the removal composition includes the following components present in the following ranges, based on the total weight of the composition:

component of % by weight preferably (% by weight) most preferably (% by weight) organic acid(s) about 1 % to about 25% about 2% to about 10% about 3% to about 7% organic solvent(s) about 5% to about 95% about 50% to about 90% about 60% to about 85% water about 1 % to about 50% about 5% to about 30% about 15% to about 25%

wherein said removal composition is substantially devoid of at least one species selected from the group consisting of a fluorine source, an amine source, an inorganic acid, oxidizing agent, a silazane source, and a silane compound source.

[0047] In a particularly preferred embodiment, the removal composition of the present invention includes water, at least one organic acid, and at least one organic solvent selected from the group consisting of di(ethylene glycol) methyl ether, tetramethylene sulfone, NMP, and combinations thereof. Most preferably, the removal composition includes water, at least one organic acid, and at least one organic solvent selected from the group consisting of di(ethylene glycol) methyl ether, tetramethylene sulfone, NMP, and combinations thereof, wherein said removal composition is substantially devoid of at least one species selected from the group consisting of a fluorine source, an amine source, an inorganic acid, oxidizing agent, a silazane source, and a silane compound source. Most preferably, the at least one organic acid is maleic acid.

[0048] In yet another embodiment, the removal composition of the present invention includes at least one organic acid, at least one organic solvent, water, thick-film photoresist residue, optionally at least one chelating agent, optionally at least one surfactant, optionally buffers), wherein the thick film photoresist residue preferably comprises monomers and/or oligomers of the thick film photoresist material. Alternatively, the removal composition of the present invention includes at least one organic acid, at least one organic solvent, water, thick-film photoresist residue, wherein the thick film photoresist residue preferably comprises monomers and/or oligomers of the thick film photoresist material, and wherein said removal composition is substantially devoid of at least one species selected from the group consisting of a fluorine source, an amine source, an inorganic acid, oxidizing agent, a silazane source, and a silane compound source.

[0049] The removal compositions described herein are particularly effective at removing thick film photoresist and/or post-ash and post-etch residue from a microelectronic assembly with minimal damage to the metal interconnecting species and/or the low-k dielectric material. In addition, it is contemplated herein that the removal compositions may be further diluted with a solvent such as water and used as a post-chemical mechanical polishing (CMP) composition to remove post-CMP residue including, but not limited to, particles from the polishing slurry, carbon-rich particles, polishing pad particles, brush deloading particles, equipment materials of construction particles, copper, copper oxides, and any other materials that are the by-products of the CMP process. Further, it is also contemplated herein that the removal compositions may be formulated as foams, fogs, subcritical or supercritical fluids. For example, the removal compositions may be added to a supercritical fluid such as carbon dioxide in a ratio of about 100 parts SCF to 1 part removal composition to about 6:1, preferably following the dilution of the removal composition with a SCF- compatible organic solvent. [0050] The removal compositions of the invention are easily formulated by simple addition of the respective ingredients and mixing to homogeneous condition. Furthermore, the removal compositions may be readily foπnulated as single-package formulations or multi-part formulations that are mixed at the point of use. The individual parts of the multi-part formulation may be mixed at the tool or in a storage tank upstream of the tool. The concentrations of the respective ingredients may be widely varied in specific multiples of the removal composition, i.e., more dilute or more concentrated, in the broad practice of the invention, and it will be appreciated that the removal compositions of the invention can variously and alternatively comprise, consist or consist essentially of any combination of ingredients consistent with the disclosure herein.

[0051] Accordingly, another aspect of the invention relates to a kit including, in one or more containers, one or more components adapted to form the compositions of the invention. Preferably, the kit includes, in one or more containers, organic acid(s), and organic solvent(s) for combining with the water at the fab. In another embodiment, the kit includes, in one or more containers, organic acid(s), organic solvent(s), and water, and may or may not be combined with additional diluent (e.g., organic solvent(s) and/or water) at the fab. The containers of the kit must be suitable for storing and shipping said removal compositions, for example, NOWPak® containers (Advanced Technology Materials, Inc., Danbury, Conn., USA).

[0052] In yet another aspect, the invention relates to methods of removal of thick film photoresist and/or post-ash and post-etch residue from the surface of the microelectronic assembly having same thereon using the removal compositions described herein. For example, thick film photoresist may be removed without damaging underlying low-k dielectrics and metallic bump and post materials, e.g., copper and cobalt.

[0053] In removal application, the removal composition is applied in any suitable manner to the surface of the microelectronic assembly having thick film photoresist and/or residue thereon, e.g., by spraying the removal composition on the surface of the assembly, by dipping (in a volume of the removal composition) of the assembly including the photoresist and/or residue, by contacting the assembly with another material, e.g., a pad, or fibrous sorbent applicator element, that is saturated with the removal composition, by contacting the assembly including the photoresist and/or residue with a circulating removal composition, or by any other suitable means, manner or technique, by which the removal composition is brought into removal contact with the thick film photoresist and/or post-ash and post-etch residue.

[0054] The compositions of the present invention, by virtue of their selectivity for thick film photoresist and residue, relative to other materials that may be present on the microelectronic assembly structure and exposed to the removal composition, such as metallization, low-k dielectric, polysilicon, silicon nitride, etc., achieve at least partial removal of the thick film photoresist and/or post-ash and post-etch residue in a highly efficient manner.

[0055] In use of the compositions of the invention for removing thick film photoresist and/or post- ash and post-etch residue from microelectronic assembly structures having same thereon, the removal composition typically is contacted with the assembly structure for a time of from about 1 to about 30 minutes, preferably about 5 to about 15 minutes, at a temperature in a range of from about 2O⁰C to about 90⁰C, preferably about 4O⁰C to about 60⁰C, most preferably about 50⁰C to about 6O⁰C. Such contacting times and temperatures are illustrative, and any other suitable time and temperature conditions may be employed that are efficacious to at least partially remove the thick film photoresist and/or post-ash and post-etch residue from the assembly structure, within the broad practice of the invention. As defined herein, "at least partial removal" corresponds to at least 90% removal of thick film photoresist and/or post-ash and post-etch residue, preferably at least 95% removal of thick film photoresist and/or post-ash and post-etch residue. Most preferably, at least 99% of the photoresist and/or post-ash and post-etch residue is removed using the compositions of the present invention. [0056] Rates of copper removal should be in a range from about 0.1 A min^"1 to about 10 A min^"1, more preferably about 0.1 A min^"1 to about 3 A min^"1.

[0057] Following the achievement of the desired removal action, the removal composition is readily removed from the microelectronic assembly to which it has previously been applied, e.g., by rinse, wash, or other removal step(s), as may be desired and efficacious in a given end use application of the compositions of the present invention. For example, the microelectronic assembly may be rinsed with deionized water.

[0058] The features and advantages of the invention are more fully shown by the illustrative examples discussed below.

Example 1

[0059] In one aspect, the removal composition is formulated in the following Formulations L-P, wherein all percentages are by weight, based on the total weight of the formulation:

Example L: 5 % Lactic acid, 45 % Tetramethylene sulfone, 45 % Di(ethylene glycol) methyl ether, 5 % Water

Example M: 5 % Lactic acid, 42.5 % Tetramethylene sulfone, 42.5 % Di(ethylene glycol) methyl ether, 10 % Water

Example N: 5 % Lactic acid, 40 % Tetramethylene sulfone, 40 % Di(ethylene glycol) methyl ether, 15 % Water

Example O: 5 % Lactic acid, 37.5 % Tetramethylene sulfone, 37.5 % Di(ethylene glycol) methyl ether, 20 % Water

Example P: 5 % Lactic acid, 35 % Tetramethylene sulfone, 35 % Di(ethylene glycol) methyl ether, 25 % Water

[0060] Thick film photoresist removal was performed on samples of blanketed substrates. The samples were dipped in removal solutions L-P at 80⁰C and the length of time needed to remove and completely dissolve the photoresist determined followed by rinsing with copious amounts of deionized water and drying under nitrogen. The results are tabulated in Table 1 hereinbelow.

Table 1 : Time needed to remove thick film photoresist using formulations L-P.

[0061] The results reported in Table 1 show that the removal and dissolution rate of the thick film photoresist increased with increasing amounts of water in the formulation. Although aqueous solutions normally are undesirable when metallic materials are present, the thickness of the metallic materials on the packaging microelectronic assemblies, e.g., bumps or posts, is so great that the removal of tens of angstroms of metal is an overall negligible amount. It is noted, if the removal compositions are used to remove post-ash and post-etch residue from the surface of a microelectronic assembly having metal interconnect material, including lines, vias or plugs, the etch rate of copper should be very low, thereby requiring a removal composition having a lower amount of water (e.g., less than 10 wt. %).

Example 2

[0062] In yet another aspect, the removal composition is formulated in the following Formulations Q-BB, wherein each formulation includes 20% water, 37.5% tetramethylene sulfone, 37.5% di(ethylene glycol) methyl ether, and the 5% of the corresponding organic acid, all percentages are by weight, based on the total weight of the formulation.

Table 2: Removal results for formulations Q-BB.

[0063] Approximately 10 micron thick film photoresist removal was performed on samples of blanketed substrates having a photoresist layer that was approximately 10 microns thick. The samples were dipped in removal solutions Q-BB at 6O⁰C and the length of time needed to remove and completely dissolve the photoresist and the etch rate of copper were determined followed by rinsing with copious amounts of deionized water and drying under nitrogen. The results are tabulated in Table 2 hereinabove. Generally, the stronger organic acids, i.e., lower pKa's, resulted in shorter removal times, probably because the acids dissociated to a greater degree.

[0064] In a further aspect, the removal composition is formulated in the following Formulations CC- KK, wherein each formulation includes 20% water, 5% maleic acid and the remainder the corresponding organic solvent system, all percentages are by weight, based on the total weight of the formulation.

Table 3: Removal results for formulations CC-KK.

[0065] Thick film photoresist removal was performed on samples of blanketed substrates. The samples were dipped in removal solutions CC-KK at 4O⁰C and the length of time needed to remove and completely dissolve the photoresist determined followed by rinsing with copious amounts of deionized water and drying under nitrogen. The results are tabulated in Table 3 hereinabove. The solvents with higher dielectric constants shorten removal time. Further, smaller solvent molecules that are not highly hydrogen bonded appear to penetrate the resist better, resulting in shorter cleaning times.

Example 3

[0066] In a still further aspect, the removal composition is formulated in the following Formulations LL-VV, wherein each formulation includes 20% water, 5% of the corresponding organic acid and the remainder the corresponding organic solvent system, all percentages are by weight, based on the total weight of the formulation.

Table 4: Removal results for formulations LL-VV.

[0067] Thick film photoresist removal was performed on samples of blanketed substrates. The samples were dipped in removal solutions LL-VV at 4O⁰C and the length of time needed to remove and completely dissolve the photoresist determined followed by rinsing with copious amounts of deionized water and drying under nitrogen. The results are tabulated in Table 4 hereinabove. Example 4

[0068] In a still further aspect, the removal composition is formulated in the following Formulations WW-LLL, wherein each formulation includes the indicated amount of maleic acid, tetramethylene sulfone, water, and di( ethylene glycol) methyl ether, all percentages are by weight, based on the total weight of the formulation.

Table 5: Removal results for formulations WW-LLL.

[0069] Thick film photoresist removal was performed on samples of blanketed substrates. The samples were dipped in removal solutions WW-LLL at 40⁰C and the length of time needed to remove and completely dissolve the , photoresist determined followed by rinsing with copious amounts of deionized water and drying under nitrogen. The results are tabulated in Table 5 hereinabove. It is noted that compositions having low percentages of water did not provide the necessary aqueous environment for the organic acids to dissociate to the extent necessary to break the cross linkages in the photoresist.

[0070] Accordingly, while the invention has been described herein in reference to specific aspects, features and illustrative embodiments of the invention, it will be appreciated that the utility of the invention is not thus limited, but rather extends to and encompasses numerous other aspects, features, and embodiments. Accordingly, the claims hereafter set forth are intended to be correspondingly broadly construed, as including all such aspects, features, and embodiments, within their spirit and scope.

Claims

THE CLAIMSWhat is claimed is:

1. A thick film photoresist removal composition, comprising at least one organic acid, at least one organic solvent, and water, wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition, and wherein said removal composition is suitable for removing thick film photoresist from a microelectronic assembly having said material thereon.

2. The removal composition of claim 1, wherein said removal composition is substantially devoid of at least one species selected from the group consisting of a fluorine source, an amine source, a silazane source, an inorganic acid, oxidizing agent, a silane compound source, and combinations thereof.

3. The removal composition of claim 1, wherein the mole ratio of organic solvent(s) relative to organic acid(s) is in a range from about 1:1 to about 60:1 and the mole ratio of organic solvent(s) relative to water is in a range from about 1 :20 to about 20: 1.

4. The removal composition of claim 1, wherein the at least one organic acid comprises a carboxylic acid selected from the group consisting of lactic acid, maleic acid, ascorbic acid, malic acid, benzoic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, mandelic acid, maleic anhydride, citric acid, phthalic acid, and combinations thereof.

5. The removal composition of claim 1, wherein the at least one organic acid comprises maleic acid.

6. The removal composition of claim 1, wherein the at least one organic solvent comprises a compound selected from the group consisting of acetone, 2-butanone, 2-pentanone, 3-pentanone, tetrahydrofuran, monoethanolamine, triethanolamine, triethylenediamine, methylethanolamine, methyldiethanolamine, pentamethyldiethylenetriamine, dimethyldiglycolamine, 1,8- diazabicyclo[5.4.0]undecene, aminopropylmorpholine, hydroxyethylmorpholine, aminoethylmoφholine, hydroxypropylmorpholine, diglycolamine, N-methylpyrrolidinone (NMP), N- octylpyrrolidinone, N-phenylpyrrolidinone, cyclohexylpyrrolidinone, vinyl pyrrolidinone, tetramethylene sulfone, methyl sulfoxide, ethylene glycol, propylene glycol (1,2-propanediol), neopentyl glycol, benzyl diethylene glycol (BzDG), acetone, diethylene glycol monomethyl ether, Methylene glycol monomethyl ether, diethylene glycol monoethyl ether, Methylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, Methylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol phenyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether (phenoxy-2- propanol), and combinations thereof.

7. The removal composition of claim 1, wherein the at least one organic solvent comprises di(ethylene glycol) methyl ether.

8. The removal composition of claim 1, further comprising an additional component selected from the group consisting of chelating agents, surfactants, buffers, and combinations thereof.

9. The removal composition of claim 1 , wherein the pH is in a range from about 0 to about 6.

10. The removal composition of claim 1 , wherein the pH is in a range from about 1 to 3.

11. The removal composition of claim 1 , wherein the removal composition is suitable for removing post-ash and post-etch residue from a microelectronic assembly having said residue thereon.

12. The removal composition of claim 1, wherein the microelectronic assembly comprises an article selected from the group consisting of semiconductor substrates and advanced packaging substrates.

13. The removal composition of claim 1, wherein the removal composition comprises water in a range from about 15 wt % to about 25 wt %, based on total weight of the composition.

14. The removal composition of claim 1, wherein the removal composition further comprises thick film photoresist residue.

15. The removal composition of claim 1, selected from the group consisting of Formulations L- LLL, wherein all percentages are by weight, based on the total weight of the formulation:

16. A kit comprising, in one or more containers, thick film photoresist removal composition reagents, wherein said removal composition comprises at least one organic acid, at least one organic solvent, and water, wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition, and wherein the kit is adapted to form the removal composition suitable for removing thick film photoresist from a microelectronic assembly having said material(s) thereon.

17. A method of removing thick film photoresist from a microelectronic assembly having said material thereon, said method comprising contacting the microelectronic assembly with a removal composition for sufficient time to at least partially remove said photoresist from the microelectronic assembly, wherein the removal composition includes at least one organic acid, at least one organic solvent, and water, and wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition.

18. The method of claim 17, wherein said removal composition is substantially devoid of at least one species selected from the group consisting of a fluorine source, an amine source, a silazane source, and a silane compound source. .

19. The method of claim 17, wherein the mole ratio of organic solvent(s) relative to organic acid(s) in the removal composition is in a range from about 1 : 1 to about 60: 1 and the mole ratio of organic solvent(s) relative to water said composition is in a range from about 1 :20 to about 20: 1.

20. The method of claim 17, wherein said contacting is carried out for a time of from about 1 minute to about 30 minutes.

21. The method of claim 17, wherein said contacting is carried out at temperature in a range of from about 2O⁰C to about 90⁰C.

22. The method of claim 17, wherein the microelectronic assembly comprises an article selected from the group consisting of semiconductor substrates, and advanced packaging substrates.

23. The method of claim 17, wherein the organic acid comprises a carboxylic acid compound selected from the group consisting of lactic acid, maleic acid, ascorbic acid, malic acid, benzoic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, mandelic acid, maleic anhydride, citric acid, phthalic acid, and combinations thereof; and

the organic solvent comprises a compound selected from the group consisting of acetone, 2-butanone, 2-pentanone, 3-pentanone, tetrahydrofuran, monoethanolamine, triethanolamine, triethylenediamine, methylethanolamine, methyldiethanolamine, pentamethyldiethylenetriamine, dimethyldiglycolamine, 1 ,8-diazabicyclo[5.4.0]undecene, aminopropylmorpholine, hydroxyethylmorpholine, aminoethylmorpholine, hydroxypropylmorpholine, diglycolamine, N-methylpyrrolidinone (NMP), N- octylpyrrolidinone, N-phenylpyrrolidinone, cyclohexylpyrrolidinone, vinyl pyrrolidinone, tetramethyl sulfone, methyl sulfoxide, acetone, ethylene glycol, propylene glycol, neopentyl glycol, benzyl diethylene glycol, diethylene glycol monomethyl ether, Methylene glycol monomethyl ether, diethylene glycol monoethyl ether, Methylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, Methylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol phenyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, and combinations thereof.

24. The method of claim 17, wherein the contacting comprises a process selected from the group consisting of: spraying the removal composition on a surface of the microelectronic assembly; dipping the microelectronic assembly in a sufficient volume of removal composition; contacting a surface of the microelectronic assembly with another material that is saturated with the removal composition; and contacting the microelectronic assembly with a circulating removal composition.

25. The method of claim 17, further comprising rinsing the microelectronic assembly with deionized water following contact with the removal composition.

26. The method of claim 17, further comprising removing post-ash and post-etch residue from a microelectronic assembly having said residue thereon.

27. The method of claim 17, wherein the removal composition comprises water in a range from about 15 wt % to about 25 wt %, based on total weight of the composition.

28. The method of claim 17, wherein the removal composition further comprises thick film photoresist.

29. The method of claim 17, wherein the removal composition is selected from the group consisting of Formulations L-LLL, wherein all percentages are by weight, based on the total weight of the formulation: Example L: 5 % Lactic acid, 45 % Tetramethylene sulfone, 45 % Di(ethylene glycol) methyl ether, 5 % Water

30. A thick film photoresist removal composition, comprising at least one organic acid, water, and at least two organic solvents selected from the group consisting of di(ethylene glycol) methyl ether, tetramethylene sulfone, NMP, and combinations thereof, wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition, and wherein said removal composition is suitable for removing thick film photoresist from a microelectronic assembly having said material thereon.

31. The removal composition of claim 30, wherein the removal composition is substantially devoid of at least one species selected from the group consisting of a fluorine source, an amine source, a silazane source, an inorganic acid, oxidizing agent, and a silane compound source.

32. A thick film photoresist removal composition, consisting essentially of at least one organic acid, at least one organic solvent, and water, wherein the removal composition includes less than about 30 wt. % water and the weight percent of organic acid < weight percent of water < weight percent of organic solvent, based on the total weight of the composition, and wherein said removal composition is suitable for removing thick film photoresist from a microelectronic assembly having said material thereon.

33. The removal composition of claim 32, wherein the at least one organic solvent comprises a compound selected from the group consisting of acetone, 2-butanone, 2-pentanone, 3-pentanone, tetrahydrofuran, monoethanolamine, triethanolamine, triethylenediamine, methylethanolamine, methyldiethanolamine, pentamethyldiethylenetriamine, dimethyldiglycolamine, 1,8- diazabicyclo[5.4.0]undecene, aminopropylmorpholine, hydroxyethylmorpholine, aminoethylmorpholine, hydroxypropylmorpholine, diglycolamine, N-methylpyrrolidinone (NMP), N- octylpyrrolidinone, N-phenylpyrrolidinone, cyclohexylpyrrolidinone, vinyl pyrrolidinone, tetramethylene sulfone, methyl sulfoxide, ethylene glycol, propylene glycol (1,2-propanediol), neopentyl glycol, benzyl diethylene glycol (BzDG), acetone, diethylene glycol monomethyl ether, Methylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol phenyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether (phenoxy-2- propanol), and combinations thereof.

34. The removal composition of claim 32, wherein the at least one organic acid comprises a carboxylic acid selected from the group consisting of lactic acid, maleic acid, ascorbic acid, malic acid, benzoic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, mandelic acid, maleic anhydride, citric acid, phthalic acid, and combinations thereof.