KR20190076904A - Photoresist stripper - Google Patents

Abstract

The present invention relates to an improved stripper solution which typically has a freezing point below about 0°C, has high load capacity, and is for removing a photoresist from a substrate. The stripper solution comprises dimethyl sulfoxide, quaternary ammonium hydroxide, and two or more carbon atoms, one or more amino substituents, and one or more hydroxyl substituents, wherein the amino and hydroxyl substituents include alkanolamines attached to two different carbon atoms. Some formulations further comprise a secondary solvent. The formulation does not include tetramethylammonium hydroxide. In addition, further provided is a method of using the stripping solution.

Description

{PHOTORESIST STRIPPER}

The present invention claims priority from U.S. Serial No. 62 / 609,562, filed December 22, 2017, which is assigned to the same assignee, which is incorporated herein by reference in its entirety.

The present invention generally relates to compositions having the ability to effectively remove photoresist from a substrate, and methods of using such compositions.

There are a number of stripper solutions for removal of photoresist, such as those described in US7632796. Due to the increased demand of wafer manufacturers for improved performance, improved stripper solution compositions are required. Strippers need to remain liquid at temperatures below normal room temperature and at temperatures often encountered in transport and warehouse storage. Additionally, the stripper formulation needs to have an advantageous load capacity for the photoresist material to be removed. In addition, little or no metal removal (etching) and long term stability are required.

Brief Description of the Invention

In one aspect of the present invention, a photoresist stripper solution is provided for effectively removing or stripping photoresist from a substrate. The stripper solution of the present invention has a particularly high loading capacity for resist materials and the ability to remain liquid when subjected to temperatures below normal room temperatures normally encountered in transportation, warehouse storage and use in some manufacturing facilities. The composition has a freezing point well below 15 [deg.] C to minimize solidification during transportation and warehouse storage. More preferred formulations have freezing points below about < RTI ID = 0.0 > 0 C. < / RTI >

Compositions in accordance with the present disclosure typically include dimethyl sulfoxide (DMSO), quaternary ammonium hydroxide, and alkanolamines. One preferred embodiment is a composition comprising from about 20% to about 90% dimethyl sulfoxide, from about 1% to about 7% quaternary ammonium hydroxide, and from about 1% to about 75% of at least two carbon atoms, An amino substituent and an alkanolamine having at least one hydroxyl substituent and wherein the amino and hydroxyl substituents are attached to two different carbon atoms. Preferred quaternary groups are (C ₁ -C ₈ ) alkyl, benzyl, arylalkyl, (C ₁ -C ₅ ) alcohols, and combinations thereof. Particularly preferred quaternary ammonium hydroxides contain at least 5 carbons, and / or may contain one or more alkanol groups. Quaternary ammonium hydroxides having one or more alkanol groups (e.g., (C ₁ -C ₅ ) alcohol groups) include choline hydroxide and tri (2-hydroxyethyl) methylammonium hydroxide. Quaternary ammonium hydroxide may include choline hydroxide, tri (2-hydroxyethyl) methylammonium hydroxide, and dimethyldipropylammonium hydroxide. Quaternary ammonium hydroxide may include choline hydroxide and dimethyldipropylammonium hydroxide. Quaternary ammonium hydroxide does not contain tetramethylammonium hydroxide (TMAH). The resulting composition further exhibits reduced human central nervous system toxicity compared to compositions comprising tetramethylammonium hydroxide (TMAH). Particularly preferred 1,2-alkanolamines include the following compounds:

Wherein R ¹ can be H, C ₁ -C ₄ alkyl or C ₁ -C ₄ alkylamino. For particularly preferred alkanolamines of formula I, R ¹ is H or CH ₂ CH ₂ NH ₂ . Additional embodiments in accordance with the present disclosure include additional or second solvents. Preferred secondary solvents include glycols, polyhydroxyl compounds and the like. A further embodiment according to the present disclosure further comprises a corrosion inhibitor.

A second aspect of the present disclosure provides a method of using the novel stripper solution described above to remove photoresist and related polymeric materials from the substrate. Contacting the substrate with the stripping solution for a time sufficient to remove a predetermined amount of photoresist, removing the substrate from the stripping solution, rinsing the substrate from the stripping solution with the solvent, and drying the substrate, The photoresist can be removed from the selected substrate having the photoresist thereon.

A third aspect of the disclosure includes an electronic device manufactured by the novel method disclosed.

Other features and advantages of the present invention will become apparent from the following more detailed description taken in conjunction with an exemplary solution illustrating the principles of the invention.

DETAILED DESCRIPTION OF THE INVENTION

For the purpose of facilitating understanding of what is being claimed, reference will now be made to the embodiments illustrated and specific language will be used to describe the same. Nevertheless, it will be understood that it is not intended to limit the scope claimed thereby, and that these and other modifications of the illustrated and further variants thereof and their further application of this principle will occur to those skilled in the art to which this disclosure pertains .

The composition according to the present disclosure comprises dimethylsulfoxide (DMSO), quaternary ammonium hydroxide, and at least two carbon atoms, at least one amino substituent, and at least one hydroxyl substituent, wherein the amino and hydroxyl substituents have two different carbons And alkanolamines attached to the atoms. Preferred quaternary substituents include alkyl, benzyl and combinations thereof, (C ₁ -C _8). The preferred compositions have freezing points well below 25 [deg.] C to minimize solidification during transportation and warehouse storage. More preferred formulations are those wherein the freezing point is below about 15 ° C, below about 0 ° C, below -5 ° C, below about -7 ° C, below about -10 ° C, below about -12 ° C, below about -15 ° C, , And / or less than about-21 占 폚, and the load capacity is from about 15 cm3 / liter to about 90 cm3 / liter. Formulations with increased concentrations of alkanolamine have the advantage of being particularly non-corrosive to carbon steel and offer less damage to conventional waste treatment systems and auxiliary equipment than other stripper solutions. Particularly preferred compositions include 1,2-alkanolamines having the formula:

Wherein R ¹ is hydrogen, (C ₁ -C ₄ ) alkyl or (C ₁ -C ₄ ) alkylamino. Some preferred formulations additionally comprise a secondary solvent. Particularly preferred formulations may comprise from about 0.2% to about 75% of a secondary solvent. Particularly useful secondary solvents include glycols and polyhydroxyl compounds as described in more detail below. Alternatively, in some embodiments, the stripper solution does not include, or is substantially free of, a secondary solvent.

Preferred formulations have freezing points well below 25 [deg.] C to minimize solidification during transportation and storage. More preferred formulations are those having a freezing point of less than about 15 ° C, less than about 0 ° C, less than about -5 ° C, less than about -7 ° C, less than about -10 ° C, less than about -12 ° C, And / or less than about-21 < 0 > C. Since the preferred stripper solution remains a liquid at low temperatures, or it is no longer necessary to liquefy the solidified drum of the stripper solution stored in an unheated warehouse or during cold weather before the solution can be used. The use of a drum heater to melt the solidified stripper solution is time consuming, requires extra handling, and can lead to incomplete melting and modification of the composition of the molten solution.

In addition, the composition according to the present disclosure exhibits a high load capacity which allows the composition to remove higher levels of photoresist without precipitation of solids. The load capacity is defined as the number of cm 3 of photoresist or bilayer material that can be removed for each liter of stripper solution before the material is redeposited on the wafer or the residue remains on the wafer. For example, if 20 liters of stripper solution can remove 300 cubic centimeters of photoresist from the surface of the wafer before redeposition occurs or before the residue remains on the wafer, the load capacity will be 300 cm3 / 20 liters = 15 cm3 / liter to be.

The sum of the weight% of DMSO and the weight% of alkanolamine in the composition of the present invention may be from about 55% to about 97%. In another embodiment, the composition comprises about 55% to about 95%, or about 65% to about 95%, or about 70% to about 97%, or about 75% to about 95%, or about 80% , Or about 85% to about 97%, or about 85% to about 95%, or about 90% to about 97%, or about 75% to about 90%, or about 75% to about 85% % To about 95% DMSO and alkanolamine. In another embodiment, the weight percent of DMSO is greater than the weight percent of the alkanolamine and the DMSO is added to the composition from 5% to about 30%, or 10% to about 30%, or 10% % To about 25%, or from 10% to about 20%. In other compositions, the weight percent of DMSO is less than the weight percent of the alkanolamine, and the DMSO comprises from 5% to about 30%, or 10% to about 30%, or 10% To about 25%, or from 10% to about 20%, or from 15% to about 20% less. Thus, in some embodiments, the solution comprises about 20% to about 90%, or about 55% to about 60%, or 30% to about 50%, or 35% to about 45%, or about 55% % ≪ / RTI > DMSO.

The composition may comprise about 2% to about 10%, or 2% to about 8%, or about 2% to about 6%, or about 2% to about 5%, or about 2% to about 4% To about 3%, or from about 1% to about 7%, or from about 1% to about 4% quaternary ammonium hydroxide. Preferred quaternary substituents include (C ₁ -C ₈ ) alkyl, benzyl, arylalkyl, (C ₁ -C ₅ ) alcohols, and combinations thereof. Some preferred quaternary ammonium hydroxides are choline-type hydroxys, which means quaternary ammonium hydroxides having at least one alcohol group attached to nitrogen, such as choline hydroxide and tri (2-hydroxyethyl) methylammonium hydroxide It is seed. Another useful quaternary ammonium hydroxide is dimethyldipropylammonium hydroxide. Preferred quaternary ammonium hydroxides are choline hydroxide and dimethyldipropyl ammonium hydroxide.

Since some of the components of the stripper solution may be provided as an aqueous solution, the composition may further comprise water. The solution may comprise 1 wt% or 2 wt% or more than 3 wt% water. In other embodiments, the solution may comprise from about 1 wt% or from about 2 wt%, or from about 3 wt% to about 7 wt%, or from about 8 wt% water.

All percentages provided herein are percent by weight based on the total weight of the composition.

A suitable level of the required alkanolamine may range from about 1% or 2% to about 75% of the composition. In some embodiments, the alkanolamine is from about 40% to about 65%, or from about 50% to about 60%, or from about 30% to about 40%, or from about 5% to about 40% of the solution.

Suitable alkanolamines have two or more carbon atoms and have amino and hydroxyl substituents on different carbon atoms. Suitable alkanolamines include but are not limited to ethanolamine, N-methylethanolamine, N-ethylethanolamine, N-propylethanolamine, N-butylethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, Diisopropanolamine, triisopropanolamine, N-methylisopropanolamine, N-ethylisopropanolamine, N-propylisopropanolamine, 2-aminopropane-1-ol, N-methyl- 1-ol, N-ethyl-2-aminopropane-3-ol, N-methyl- Ol, N-methyl-1-aminobutan-2-ol, N-ethyl-1-aminobutan- 2-aminobutane-1-ol, 3-aminobutan-1-ol, N-methyl- Aminobutan-4-ol, N-methyl-1-aminobutan-4-ol, N-ethyl- 2-methylpropan-1-ol, 1-aminopentan-4-ol, 2-amino-4-methylpentane- 1-ol, 2-aminohexan-1-ol, 3-aminohexan-4-ol, , 2-aminopropane-1,3-diol, tris (oxymethyl) aminomethane, 1,2-diaminopropane-3-ol, Ethoxy) ethanol, but are not limited thereto.

In use, the secondary solvent comprises from about 0.2% to about 35%, or from about 0.2% to about 30%, or from about 0.2% to about 25%, or from about 0.2% to about 20%, or from about 0.2% , Or from about 0.2% to about 12%, or from about 5% to about 12%. The secondary solvent may comprise an alcohol, or a polyhydroxyl compound, or a combination of two or more thereof.

Secondary solvent alcohols and polyhydroxyl compounds have two or more hydroxyl groups and do not contain silver ester, amine or ether groups. The alcohol or polyhydroxyl compound may be aliphatic, alicyclic, cyclic or aromatic, but may preferably be aliphatic or alicyclic. The alcohol or polyhydroxyl compound may be saturated or unsaturated and preferably has no more than one unsaturated bond or no unsaturated bond. Alcohols and polyhydroxyl compounds preferably do not contain heteroatoms. Alcohols and polyhydroxyl compounds preferably contain only carbon, oxygen and hydrogen atoms.

As examples of secondary solvent alcohols, mention may be made of straight chain and branched chain and aromatic alcohols. For illustrative purposes, the alcohol in the solution is selected from the group consisting of methanol, ethanol, propanol, isopropyl alcohol, butanol, tert-butyl alcohol, tert-amyl alcohol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 9-hexadecen- Octadecanol, 1-octadecanol, 1-octadecanol, 1-octadecanol, 1-octadecanol, 1-octadecanol, Heptacanoic acid, heptacanoic acid, 1-octacosanol, 1-triacontanol, 1-tetra triacontanol, 1-tetra triacontanol, cetearyl alcohol, furfuryl alcohol and tetrahydrofurfuryl alcohol. In an illustrative example, the solution may comprise at least one of furfuryl alcohol, tetrahydrofurfuryl alcohol, tert-butyl alcohol or 3-methyl-3-pentanol.

As mentioned above, the secondary solvent may be a polyhydroxyl compound having two or more hydroxyl groups. The polyhydroxyl compound preferably has a molecular weight of 500 or less, or 400 or less, or 350 or less, or 300 or less, or 275 or less, or 250 or less, or 225 or 200 or less, or 175 or less, 125 or less, or 100 or less, or 75 or less.

The polyhydroxyl compound as the secondary solvent is selected from the group consisting of ethylene glycol; 1,2-propanediol (propylene glycol); 1,3-propanediol, 1,2,3-propanetriol; 1,2-butanediol; 1,3-propanediol; 2,3-butanediol; 1,4-butanediol; 1,2,3-butanetriol; 1,2,4-butanetriol; 1,2-pentanediol; 1,3-pentanediol; 1,4-pentanediol; 2,3-pentanediol; 2,4-pentanediol; 3,4-pentanediol; 1,2,3-pentanetriol; 1,2,4-pentanetriol; 1,2,5-pentanetriol; 1,3,5-pentanetriol; Etohexadiols; p-methane-3,8-polyhydroxyl compounds; 2-methyl-2,4-pentanediol; 2,2-dimethyl-1,3-propanediol; glycerin; Trimethylol propane; Xylitol; Arabitol; 1,2- or 1,3-cyclopentanediol; 1,2- or 1,3-cyclohexanediol; 2,3-norbornanediol; 1,8-octanediol; 1,2-cyclohexane-dimethanol; 1,3-cyclohexanedimethanol; 1,4-cyclohexanedimethanol; 2,2,4-trimethyl-1,3-pentanediol; Hydroxypivalic hydroxypivalate; 2-methyl-1,3-propanediol; 2-butyl-2-ethyl-1,3-propanediol; 2-ethyl-2-isobutyl-1,3-propanediol; 1,6-hexanediol; 2,2,4,4-tetramethyl-1,6-hexanediol; 1,10-decanediol; 1,4-benzene dimethanol; Hydrogenated bisphenol A; 1,1,1-trimethylol propane; 1,1,1-trimethylol ethane; Pentaerythritol; Erythritol; Traitol; Dipentaerythritol; Sorbitol; Etc., and combinations of two or more of the above-mentioned polyhydroxyl compounds and polyhydroxyl compounds.

In an illustrative example, the solution is a mixture of ethylene glycol, 1,2-propanediol (propylene glycol), 1,3-propanediol, 1,4-pentanediol, 1,2- And a polyhydroxyl solution.

The composition may also optionally comprise at least one corrosion inhibitor. Suitable corrosion inhibitors include aromatic hydroxyl compounds such as catechol and resorcinol; Alkyl catechols such as methyl catechol, ethyl catechol and t-butyl catechol, phenol and pyrogallol; Aromatic triazoles such as benzotriazole; Alkylbenzotriazoles; Sugar alcohols such as glycerol and sorbitol; Carboxylic acids such as formic, acetic, propionic, butyric, isobutyric, oxalic, malonic, succinic, glutaric, maleic, fumaric, benzoic, phthalic, 1,2,3-benzenetricarboxylic, glycolic , Lactic acid, malic acid, citric acid, acetic anhydride, phthalic anhydride, maleic anhydride, succinic anhydride, salicylic acid, gallic acid and gallic acid esters such as methyl gallate and gallic acid; Metal salts such as copper (II) nitrate; Copper (II) bromide; Copper (II) chlorate; Copper (II) chloride; Copper (II) fluorosilicate; Copper (II) formate; Copper selenate (II); Copper sulfate (II); Organic salts of carboxy containing organics including the compounds described above, basic materials such as ethanolamine, trimethylamine, diethylamine and pyridine such as 2-aminopyridine, and the like, and chelate compounds such as 1,2-propanediamine tetramethylene Phosphoric acid chelate compounds including phosphonic acid and hydroxyethanesulfonic acid, carboxylic acid-based chelate compounds such as ethylenediaminetetraacetic acid and its sodium and ammonium salts, dihydroxyethylglycine and nitrilotriacetic acid, amine-based chelate compounds such as bis But are not limited to, pyridine, tetraphenylporphyrine and phenanthroline, and oxime chelate compounds such as dimethylglyoxime and diphenylglyoxime. One type of corrosion inhibitor can be used, or a combination of corrosion inhibitors can be used. Corrosion inhibitors have been found to be useful at concentrations ranging from about 1 ppm to about 10%. In embodiments, the solution may comprise from about 0.05 wt% to about 7 wt% of the first corrosion inhibitor, and from about 0.001 wt% to about 3 wt% of the second corrosion inhibitor. In other embodiments, the solution comprises at least 0.05 wt%, or at least 0.1 wt%, or at least 1 wt%, and / or less than about 3 wt%, and / or less than about 7 wt% of the first corrosion inhibitor . In other embodiments, the solution contains at least 0.001%, or at least 0.01%, or at least 0.1%, and / or less than about 1%, and / or less than about 2% Of the second corrosion inhibitor. The first and second corrosion inhibitors are not the same. Both the first corrosion inhibitor and the second corrosion inhibitor may be selected from the corrosion inhibitors described above. In one embodiment, the at least one corrosion inhibitor is selected from the group consisting of copper (II) nitrate; Copper (II) bromide; Copper (II) chlorate; Copper (II) chloride; Copper (II) fluorosilicate; Copper (II) formate; Copper selenate (II); And / or copper sulfate (II) alone or in combination with at least one of the corrosion inhibitors described above. In an alternative embodiment, the at least one corrosion inhibitor is selected from the group consisting of copper (II) nitrate, copper (II) bromide; Copper (II) chlorate; Copper (II) chloride; Copper (II) fluorosilicate; Copper (II) formate; Copper selenate (II); Copper sulfate (II) and / or resorcinol. In another preferred embodiment, the corrosion inhibitor may comprise copper (II) nitrate and resorcinol.

The stripping agent may also comprise any one or more surfactant, typically in a concentration ranging from about 0.01% to about 3%, or from about 0.01% to about 1% by weight. Any of the preferred surfactants may comprise a fluorosurfactant. One example of a preferred fluorosurfactant is DuPont FSO (a fluorinated telomeric B monoether containing polyethylene glycol (50%), ethylene glycol (25%), 1,4-dioxane (<0.1% to be. Another example of a preferred fluorosurfactant is DuPont, Capstone, FS-10 (30% perfluoroalkylsulfonic acid in water).

A preferred temperature of at least 50 캜 is preferred for contacting the substrate, while for most applications, a temperature of about 50 캜 to about 75 캜 is more preferred. For certain applications where the substrate is sensitive or requires a longer removal time, a lower contact temperature is appropriate. For example, in reworking a substrate, it may be appropriate to maintain the stripper solution at a temperature of at least 20 [deg.] C for a longer period of time in order to remove the photoresist and avoid damage to the substrate.

Upon immersion of the substrate, agitation of the composition further promotes photoresist removal. Stirring can be carried out by mechanical stirring, circulation, or bubbling of the inert gas through the composition. After removal of a predetermined amount of photoresist, the substrate is removed from contact with the stripper solution and rinsed with water or alcohol. Deionized water is the preferred form of water, and isopropanol is the preferred alcohol. For the substrate having the component to be oxidized, the rinsing is preferably carried out under an inert atmosphere. Preferred stripper solutions according to the present disclosure have improved loading capacity for photoresist materials compared to current commercial products and are capable of treating multiple substrates with a provided volume of stripper solution.

The stripper solution provided in the present disclosure can be used to remove polymeric resist materials or certain types of two-layer resists present as a single layer. For example, a two-layer resist typically has a first inorganic layer that is covered with a second polymer layer, or it may have two polymer layers. Using the method taught below, a single layer of polymer resist can be effectively removed from a standard wafer with a single polymer layer. The same method can also be used to remove a single polymer layer from a wafer having two layers of a first inorganic layer and a second or outer polymer layer. Finally, the two polymer layers can be effectively removed from the two-layered wafer consisting of two polymer layers.

This disclosure describes a process for removing thick photoresist, which may be a resist of from about 10 microns to about 200 microns or more, or from about 15 microns to 200 microns, or from about 20 microns to about 200 microns, for advanced packaging applications for semiconductor devices The chemical solution used to make the solution. In other cases, the chemical solution may be used to remove photoresist from about 1 탆 to about 200 탆 or more, or from about 2 탆 to 200 탆, or from about 3 탆 to about 200 탆. In one embodiment, the described solution comprises DMSO, monoethanolamine (MEA), water, quaternary ammonium hydroxide, and at least one corrosion inhibitor. The quaternary ammonium hydroxide and stripper solutions of the present invention are substantially free of TMAH. Quaternary ammonium hydroxide is primarily choline hydroxide or dimethyldipropyl ammonium hydroxide. By "substantially free" is meant an amount of less than 1%, alternatively less than 0.1%, alternatively less than 0.01% or less than 0.001%. "Substantially free" also includes the absence of TMAH. In a further embodiment, the quaternary ammonium hydroxide does not comprise TMAH. The solution also optionally comprises a surfactant. The solution may comprise more than 1 or 3% by weight of water. In embodiments, the solution may comprise about 1 wt% or 2 wt% or 3 wt% to about 7 wt% or 8 wt% water. In another embodiment, the ratio of the amount of water to the amount of quaternary ammonium hydroxide in the solution is greater than about 1.2, greater than about 1.5, greater than about 1.8, greater than about 2.0, greater than about 2.2, and / or greater than about 2.5. In an alternative embodiment, the ratio of the amount of water to the amount of quaternary ammonium hydroxide in the solution is from about 1.2 to about 1.5. The solution may also comprise more than 25% by weight MEA.

Some embodiments of the compositions of the present invention are substantially free of, or alternatively do not include, one or more of the following optional combinations (these terms are as previously defined): nitrogen containing solvents, bis-choline Salts of organic acids, inorganic acids, inorganic bases, metal hydroxides, glycols, polyols such as triethanolamine, aminoethanolamine, glycol ethers, hydrogen peroxide, oxidizing agents, , NMP, surfactants, metal-containing compounds, sugar alcohols, and aromatic hydroxyl compounds, any combination thereof. In another embodiment, the composition comprises substantially sodium, and / or calcium, and / or aminocarboxylic acid, and / or alcohol, and / or ethylenediamine, and / or ethylene triamine, and / or thiophenol I will not (or will not) include it. In some embodiments, the compositions disclosed herein are formulated to be substantially free of or not including at least one of the following chemical compounds: alkylthiol and organosilane. In some embodiments, the compositions disclosed herein are formulated to be substantially free or free of at least one of the halide containing compounds, such as may be substantially free or not comprising one or more of the following: Fluoride, bromine, chlorine or iodine containing compounds. In other embodiments, the composition may or may not substantially comprise sulfonic acid and / or phosphoric acid and / or sulfuric acid and / or nitric acid and / or hydrochloric acid. In other embodiments, the composition may or may not substantially comprise sulfate and / or nitrate and / or sulfite and / or nitrite. In other embodiments, the composition may or may not substantially comprise: ethylenediamine, a sodium containing compound and / or a calcium containing compound and / or a manganese containing compound or a magnesium containing compound and / or a chromium containing compound And / or a sulfur-containing compound and / or a silane-containing compound and / or a phosphorus-containing compound. Some embodiments may or may not substantially include a surfactant. Some embodiments may be substantially free of or not including an amphoteric salt and / or a cationic surfactant, and / or an anionic surfactant, and / or a bionic ionic surfactant, and / or a nonionic surfactant . Some embodiments may or may not substantially comprise imidazole and / or hydrate. Some embodiments may or may not substantially comprise pyrrolidone and / or acetamide. Some embodiments may or may not substantially comprise any amine. Some embodiments may or may not substantially include peroxide compounds and / or peroxides and / or persulfates and / or percarbonates, and their acids, and salts thereof. In some embodiments, the iodate and / or perboric acid and / or borate and / or percarbonate and / or peroxyacid and / or cerium compound and / or cyanide and / or periodate and / or ammonium molybdate and / Or may or may not substantially contain ammonia. The ingredients that the composition of the present invention may not include, any combination of the ingredients may be any combination thereof, as described herein.

The compositions of the present invention may also include one or more of the following additives: chelating agents, chemical modifiers, dyes, biocides, and other additives. The additive (s) may be added in an amount up to a total amount of up to about 5% by weight of the composition, so that it does not adversely affect the performance of the composition. In other embodiments, the composition will be substantially free or free of chelating agents, dyes, biocides and / or other additives.

In Example 1, various stripping compositions were used to remove thick spin-on photoresist from a silicon wafer having a plated Cu pillar and a Sn / Ag solder cap. The resist removal was performed using an immersion process in a beaker.

For the immersion process, coupon size samples of semiconductor wafers were processed in a beaker. The beaker was filled with 100 mL of the stripping composition and heated to a target temperature of 70 &lt; 0 &gt; C. Once the stripping composition reached the target temperature, the coupon was placed in a holder in a beaker and provided a slight agitation by a stir bar. Throughout the process, the temperature was maintained at a target temperature of 70 ° C. After a total treatment time of 60 minutes, the coupon was removed from the beaker, rinsed with deionized water and IPA and dried with an air stream.

In the experiments described below, resist removal was observed and recorded accordingly. If all the resist has been removed from the wafer coupon surface, the resist removal is defined as "clean "; Is defined as "substantially clean" if at least 95% of the resist is removed from the surface, but not all of the resist; Is defined as "partially cleaned" if at least about 80% of the resist, but less than 95% of the resist, has been removed from the surface.

The following abbreviations are used in the various compositions listed below: DMSO = dimethyl sulfoxide; MEA = monoethanolamine; MMB = 3-methoxy 3-methyl-1-butanol; TMAH = tetramethylammonium hydroxide; PG = propylene glycol; DMDPAH = dimethyldipropylammonium hydroxide; THFA = tetrahydrofurfuryl alcohol; DB = diethylene glycol monobutyl ether; CH = choline hydroxide.

Table 1 below lists the various stripper compositions of the present invention and comparison stripper compositions.

Example  One

Table 2 lists the stripper compositions tested for Example 1 using an immersion process, and semiconductor wafers with plated Cu fillers and Sn / Ag solder caps. The heating temperature and time for all the compositions in Table 2 were 70 ° C and 60 minutes, respectively.

In Example 2, various stripper compositions were used to remove a negative dry film photoresist of 40 mu m thickness from silicon wafers with plated Cu features. The resist removal was performed using an immersion process in a beaker.

For the immersion process, coupon size samples of semiconductor wafers were processed in a beaker. The beaker was filled with 100 mL of the stripping composition and heated to a target temperature of 70 &lt; 0 &gt; C. Once the stripping composition reached the target temperature, the coupon was placed in a holder in a beaker and provided a slight agitation by a stir bar. Throughout the process, the temperature was maintained at a target temperature of 70 ° C. After a total treatment time of 30-60 minutes, the coupon was removed from the beaker, rinsed with deionized water and IPA and dried with an air stream.

In the experiments described below, resist removal was observed and recorded accordingly. If all the resist has been removed from the wafer coupon surface, the resist removal is defined as "clean "; Is defined as "substantially clean" if at least 95% of the resist is removed from the surface, but not all of the resist; Is defined as "partially cleaned" if at least about 80% of the resist, but less than 95% of the resist, has been removed from the surface.

Example  2

Table 3 below lists semiconductor wafers having a stripper composition tested for Example 2 using an immersion process, and a thick dry film photoresist with plated Cu features. The heating temperature in Table 3 was 70 ° C.

Example  3

In Example 3, various stripper compositions were used to evaluate metal corrosion. A metal corrosion test was performed using an immersion process in a beaker.

For the immersion process, a coupon size sample of a semiconductor wafer containing a known thickness of Cu layer, and a coupon size sample of a semiconductor wafer containing a known thickness of Sn layer were treated in a beaker. Cu and Sn thickness layers were deposited on the wafer by physical vapor deposition. The beaker was filled with 100 mL of the stripping composition and heated to a target temperature of 70 &lt; 0 &gt; C. Once the stripping composition reached the target temperature, a sample coupon having each metal and a known surface area on it was placed in a holder in a beaker and agitation was provided by a stir bar. Throughout the process, the temperature was maintained at a target temperature of 70 ° C. After a total treatment time of 60 or 120 minutes, the coupon was taken out of the beaker.

A sample of the solution was collected and the concentration of dissolved Cu and Sn was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The concentrations of dissolved Cu and Sn were also measured in a sample of the solution taken as a control before the solution was heated and used for coupon treatment. The change in the concentration of dissolved Cu or Sn refers to the amount of metal dissolved by the formulation during the coupon cleaning process. A small change in the dissolved metal concentration of? 10 ppm, relative to the control concentration, indicates very good metal compatibility, i.e. a low metal etch rate.

Table 4 below lists the ICP-AES measurements for Example 3 for dissolved Cu and Sn concentrations using an immersion process. The amounts of control for Cu and Sn are listed in columns 3 and 4 of Table 4, respectively, and the measured quantities are listed in the next four columns as labeled. A concentration of &lt; = 10 ppm for the control is preferred, and the target is 0 ppm. The heating temperature of all the compositions in Table 4 was 70 占 폚, and the treatment times were 60 minutes and 120 minutes, respectively. The amount of Cu or Sn (removed from the wafer coupon) dissolved by the stripper solution can be determined by subtracting the control amount from the measurement amount. For example, for formulation 1, 2 ppm (2 ppm minus 0 ppm) of Cu was dissolved by the stripper solution at 70 占 폚 and 60 minutes; 3.8 ppm (4.3 ppm - 0.5 ppm) of Sn was dissolved by the stripper solution at 70 DEG C and 60 minutes.

Table 5 lists the freezing points of the various formulations and lower temperatures are preferred for improved storage and transport capabilities.

Example  4

In Example 4, a test was conducted to evaluate the stability of quaternary ammonium hydroxide. The stability was tested by heating 100 mL of the formulation in a beaker to a target temperature of 70 째 C. The target temperature was maintained for 8 hours. Small samples were taken from the beaker at a target interval of 2 hours and tested by acid-base titration.

Table 6 below lists the percent by weight change in base concentration measured by acid-base titration at each target interval up to 8 hours. A smaller percentage change in weight per target interval is preferred, indicating a more stable formulation. Improved formulation stability provides the user with longer product shelf life storage, longer product bath life during use, and improved photoresist load capacity. The change in weight percent of base at time 0 to time 8 hours is reported in the last column of the table, indicating that formulation 10 has the smallest change.

Although the present invention has been described with reference to one or more embodiments, it will be understood that various changes may be made and equivalents substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Accordingly, it is not intended to limit the invention to the specific embodiments disclosed as the best mode contemplated for carrying out this invention, but the invention will include all embodiments falling within the scope of the claims. In addition, all numerical values identified in the detailed description should be interpreted as if the exact values and the approximate values are all accurately ascertained. Furthermore, any use of the terms "having", "including", "containing", etc. in the specification and claims is intended to cover such alternatives as "having substantially" and "consisting of" Quot ;, " comprising ", "containing ", and the like. In addition, the use of articles to describe any of the components of the stripper composition should be interpreted as if they were replaced by "one or more"

Claims (20)

A stripper solution for removing photoresist from a substrate,
From about 20% to about 90% by weight of dimethyl sulfoxide;
From about 1% to about 7% by weight of quaternary ammonium hydroxide;
From about 1% to about 75% by weight of an alkanolamine;
From about 0.001 wt% to about 7 wt% corrosion inhibitor; And
From about 1% to about 8% by weight of water
/ RTI &gt;
Said solution exhibiting freezing points below about 0 캜;
Wherein the quaternary ammonium hydroxide is substantially free of tetramethylammonium hydroxide. The solution according to claim 1, wherein the quaternary ammonium hydroxide has a substituent which is (C ₁ -C ₈ ) alkyl, arylalkyl, benzyl, (C ₁ -C ₅ ) alcohol and combinations thereof. The solution according to claim 2, wherein the quaternary ammonium hydroxide comprises at least one of choline hydroxide, tri (2-hydroxyethyl) methylammonium hydroxide or dimethyldipropylammonium hydroxide. The solution of claim 1, wherein the alkanolamine is present in an amount from about 25% to about 75% by weight. 5. The solution according to claim 4, wherein the alkanolamine comprises monoethanolamine. 5. The method of claim 4,
The dimethyl sulfoxide is present in an amount from about 55% to about 60% by weight;
The quaternary ammonium hydroxide is present in an amount from about 1.5% to about 3.5% by weight;
The alkanolamine is present in an amount from about 30% to about 40% by weight;
Wherein the first corrosion inhibitor is present in an amount from about 0.001 wt% to about 3 wt%. 7. The solution of claim 6, wherein the alkanolamine comprises monoethanolamine. 8. The solution of claim 7, wherein the first corrosion inhibitor is selected from the group consisting of resorcinol, glycerol, sorbitol and copper (II) nitrate. 8. The method of claim 7, wherein the first corrosion inhibitor comprises copper (II) nitrate; Copper (II) bromide; Copper (II) chlorate; Copper (II) chloride; Copper (II) fluorosilicate; Copper (II) formate; Copper selenate (II); And / or a solution of copper sulfate (II) and resorcinol. 9. The solution of claim 8, wherein the first corrosion inhibitor is present in an amount from about 0.001 wt% to about 0.1 wt%. The solution of claim 1, further comprising from about 0.01% to about 3% by weight of a surfactant. The solution of claim 1, wherein the first corrosion inhibitor is selected from the group consisting of resorcinol, glycerol, sorbitol and copper (II) nitrate. 13. The solution of claim 12, further comprising from about 0.001% to about 3% by weight of a second erosion inhibitor. 14. The solution of claim 13, wherein the second corrosion inhibitor is different from the first corrosion inhibitor and is selected from the group consisting of resorcinol, glycerol, sorbitol and copper (II) nitrate. 15. The method of claim 14, wherein the dimethyl sulfoxide is present in an amount from about 35 weight percent to about 45 weight percent, the quaternary ammonium hydroxide is present in an amount from about 1.5 weight percent to about 3.5 weight percent, Wherein the first corrosion inhibitor is present in an amount from about 0.05% to about 3% by weight and the second corrosion inhibitor is present in an amount from about 0.001% to about 0.1% &Lt; / RTI &gt; 16. The solution according to claim 15, wherein the alkanolamine comprises monoethanolamine. The solution of claim 1, wherein the freezing point is below about -15 ° C. The solution according to claim 1, wherein the freezing point is below about -21 캜. A stripper solution for removing photoresist from a substrate,
From about 20% to about 90% by weight of dimethyl sulfoxide;
From about 1% to about 7% by weight of quaternary ammonium hydroxide;
From about 1% to about 75% by weight of an alkanolamine;
From about 0.001 wt% to about 7 wt% corrosion inhibitor; And
water
;
Wherein the ratio of the amount of water to the amount of quaternary ammonium hydroxide is greater than about 1.2;
Said solution exhibiting freezing points below about 0 캜;
Wherein the quaternary ammonium hydroxide is substantially free of tetramethylammonium hydroxide. A method of cleaning a resist from a substrate,
Contacting the resist on the substrate with the stripping solution for a time sufficient to remove a predetermined amount of resist, and removing the substrate from the stripping solution,
The stripping solution
From about 20% to about 90% by weight of dimethyl sulfoxide;
From about 1% to about 7% by weight of quaternary ammonium hydroxide;
From about 1% to about 75% by weight of an alkanolamine;
From about 0.001 wt% to about 7 wt% corrosion inhibitor; And
From about 1% to about 8% by weight of water
/ RTI &gt;
Said solution exhibiting freezing points below about 0 캜;
Wherein the quaternary ammonium hydroxide is substantially free of tetramethylammonium hydroxide.