JP2019113848A - Photoresist stripper - Google Patents

Abstract

To provide improved stripper solutions for removing photoresists from substrates that typically have freezing points below about 0°C and high loading capacities, and methods for use of the stripping solutions.SOLUTION: The stripper solutions comprise dimethyl sulfoxide, quaternary ammonium hydroxide, and an alkanolamine having at least two carbon atoms, at least one amino substituent and at least one hydroxyl substituent, the amino and hydroxyl substituents attached to two different carbon atoms. Formulations are free of tetramethylammonium hydroxide, and some formulations can additionally contain a secondary solvent.SELECTED DRAWING: None

Description

  The present invention claims priority to US Patent Application No. 62 / 609,562 filed December 22, 2017 having the same title of the invention. The above application is incorporated herein by reference in its entirety.

  The present invention relates generally to compositions capable of effectively removing photoresist from a substrate, and to methods of using such compositions.

  There are many stripper solutions for removing photoresist, such as those disclosed in US Pat. No. 7,632,796. With the increasing demands of wafer manufacturers for improved performance, there is a need for improved stripper solution compositions. Strippers require that they remain liquid at temperatures below normal room temperature and temperatures often encountered during shipping and storage. In addition, stripper formulations are required to have advantageous loading capabilities for the photoresist material to be removed. In addition, little or no amount of metal removal (etching) and long-term stability are desired.

  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 is particularly exposed to temperatures below normal room temperature typically encountered during transport, storage, and use in some manufacturing facilities, with particularly high holding capacity for resist materials. And the ability to remain liquid when The composition has a freezing point well below 15 ° C. to minimize solidification during shipping and storage. More preferred formulations have a freezing point below about 0 ° C.

の化合物を含み、
上記式中、Ｒ^１はＨ、Ｃ_１−Ｃ_４アルキル、又はＣ_１−Ｃ_４アルキルアミノであってよい。式Ｉの特に好ましいアルカノールアミンに関しては、Ｒ^１はＨ、又はＣＨ_２ＣＨ_２ＮＨ_２である。本開示によるさらなる実施態様は付加的又は二次的な溶媒を含有する。好ましい二次溶媒はグリコール、ポリヒドロキシル化合物、及びこれに類するものを含む。本開示によるさらなる実施態様はさらに腐食抑制剤を含有する。 The composition according to the invention typically contains dimethyl sulfoxide (DMSO), quaternary ammonium hydroxide and an alkanolamine. One preferred embodiment is about 20% to about 90% dimethylsulfoxide, about 1% to about 7% quaternary ammonium hydroxide, and about 1% to about 75% alkanolamine, at least 2 And an alkanolamine having one carbon atom, at least one amino substituent, and at least one hydroxyl substituent, wherein the amino and hydroxyl substituents are attached to two different carbon atoms. Preferred quaternary group _{is (C} 1 -C ₈₎ alkyl, benzyl, _{arylalkyl, (C} 1 -C ₅₎ alcohols, and combinations thereof. Particularly preferred quaternary ammonium hydroxides have at least 5 carbon atoms and / or may contain at least one alkanol group. Quaternary ammonium hydroxides having at least one alkanol group (e.g. (C 1 _{-C 5)} alcohol groups) include choline hydroxide, and tri (2-hydroxyethyl) methyl ammonium hydroxide. The quaternary ammonium hydroxide may include choline hydroxide, tri (2-hydroxyethyl) methyl ammonium hydroxide, and dimethyl dipropyl ammonium hydroxide. The quaternary ammonium hydroxide may include choline hydroxide and dimethyldipropyl ammonium hydroxide. Quaternary ammonium hydroxide does not contain tetramethyl ammonium hydroxide (TMAH). The resulting composition further exhibits reduced human central nervous system toxicity as compared to a composition comprising tetramethyl ammonium hydroxide (TMAH). Particularly preferred 1,2-alkanolamines have the formula:

Containing the compounds of
In the above formula, R ¹ may 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 . Further embodiments according to the present disclosure contain additional or secondary 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 material from a substrate. The substrate is contacted with the stripping solution for a sufficient amount of time to remove the desired amount of resist, and the substrate is removed from the stripping solution, the stripping solution is rinsed away from the substrate, and the substrate is dried. Thereby, the photoresist can be removed from the selected substrate having the photoresist thereon.

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

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

  To facilitate an understanding of the claimed invention, reference is made herein to exemplary embodiments, and specific language will be used to describe these embodiments. It goes without saying that it is not intended to limit the scope of the claims, variations and further modifications as would normally occur to those skilled in the art to which the present disclosure relates, and further modifications of the principles of the present invention. It should be understood that the following applications are envisaged.

を有する１，２−アルカノールアミンを含有し、
上記式中、Ｒ^１は水素、（Ｃ_１−Ｃ_４）アルキル、又は（Ｃ_１−Ｃ_４）アルキルアミノである。いくつかの好ましい製剤はこれに加えて二次溶媒を含有する。特に好ましい製剤は約０．２％〜約７５％の二次溶媒を含有してよい。特に有用な二次溶媒は下で詳述するグリコール及びポリヒドロキシル化合物を含む。或いは、いくつかの事例では、ストリッパー溶液は二次溶媒を含まないか、又は本質的に含まない。
好ましい製剤は、輸送及び保管中の凝固を最小限に抑えるために、２５℃を充分に下回る凝固点を有する。より好ましい製剤は約１５℃未満、約０℃未満、約−５℃未満、約−７℃未満、約−１０℃未満、約−１２℃未満、約−１５℃未満、約−１８℃未満、及び／又は約−２１℃未満の凝固点を有する。好ましいストリッパー溶液は低温で液体のままであるので、寒冷気候時に受け取られた、又は暖房のない倉庫内に保管された凝固されたストリッパー溶液ドラムを、溶液が使用できるようになる前に液化する必要がなくなるか又は最小化される。凝固されたストリッパー溶液を溶融するためにドラムヒーターを使用することは多大な時間を費やし、余分のハンドリングを必要とし、そして不完全な溶融をもたらし、そして溶融された溶液の組成を変更する結果となる可能性がある。 The compositions according to the present disclosure have dimethylsulfoxide (DMSO), quaternary ammonium hydroxide, an alkanolamine and at least two carbon atoms, at least one amino substituent, and at least one hydroxyl substituent. Included are alkanolamines in which the amino and hydroxyl substituents are attached to two different carbon atoms. Preferred quaternary substituents are (C ₁ -C ₈ ) alkyl, benzyl and combinations thereof. Preferred compositions have a freezing point well below 25 ° C. to minimize solidification during shipping and storage. More preferred formulations are 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, less than about -15 ° C, less than about -18 ° C. and / or has a freezing point of less than about -21 ° C., and has a holding capacity of up to about 15cm ³ / liter to about 90cm ³ / liter. Formulations with elevated levels of alkanolamines are particularly non-corrosive to carbon steel and have the advantage of being less harmful to typical waste treatment systems and ancillary equipment than other stripper solutions. Have. Particularly preferred compositions have the formula:

Containing 1,2-alkanolamines having
In the above formula, ^{R 1} is _{hydrogen, (C} 1 -C ₄₎ alkyl, or _(C 1 -C ₄₎ alkylamino. Some preferred formulations additionally contain a secondary solvent. Particularly preferred formulations may contain about 0.2% to about 75% of a secondary solvent. Particularly useful secondary solvents include the glycols and polyhydroxyl compounds detailed below. Alternatively, in some cases, the stripper solution is free or essentially free of the secondary solvent.
Preferred formulations have a freezing point well below 25 ° C. to minimize coagulation during shipping and storage. More preferred formulations are 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, less than about -15 ° C, less than about -18 ° C. And / or have a freezing point less than about -21 ° C. Since the preferred stripper solution remains liquid at low temperatures, it is necessary to liquefy the solidified stripper solution drum received in cold weather or stored in a warehouse without heating, before the solution can be used Disappears or is minimized. Using a drum heater to melt the solidified stripper solution takes a great deal of time, requires extra handling, results in incomplete melting, and results in changing the composition of the melted solution Could be

In addition, the composition according to the present disclosure exhibits a high retention capacity which allows the composition to remove higher levels of photoresist without precipitation of solids. Retention capacity is defined as cm ^{3 of} photoresist or bilayer material that can be removed per liter of stripper solution before material is redeposited on the wafer or before residue remains on the wafer Ru. For example, before the re-deposition occurs, or before the residue remains on the wafer, if the A 20 L stripper solution can remove photoresist 300 cm ³ from the wafer surface, the holding capacity 300 cm ^3/20 l = 15cm ^{It is 3} / liter.

  The sum of the weight percent of DMSO in the composition of the present invention and the weight percent of the alkanolamine may be about 55% to about 97%. In other embodiments, the composition is 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% to About 97%, 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%, or It may contain about 90% to about 95% DMSO and an alkanolamine. In some embodiments, the weight percent of DMSO is greater than the weight percent of the alkanolamine, and DMSO is 5% to about 30%, or 10% to about 30%, or 10% than the% alkanolamine present. It may be present in the composition in amounts up to about 25%, or 10% to about 20%. In other compositions, the weight percent of DMSO is less than the weight percent of the alkanolamine, and DMSO is 5% to about 30%, or 10% to about 30%, or 10% to the% alkanolamine present. About 25%, or 10% to about 20%, or 15% to about 20% lower may be present in the composition. Thus, in some embodiments, the solution is about 20% to about 90%, or about 55% to about 60%, or about 30% to about 50%, or 35% to about 45%, or about 55% to It may contain about 75% DMSO.

The composition is 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%, or about 2% -About 3%, or about 1% to about 7%, or about 1% to about 4% of quaternary ammonium hydroxide may be included. 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 hydroxides, which are quaternary ammonium hydroxides having at least one alcohol group bound to nitrogen, such as choline hydroxide, and tri (2-hydroxyethyl) methyl ammonium hydroxide is meant. Another useful quaternary ammonium hydroxide is dimethyl dipropyl ammonium hydroxide. Preferred quaternary ammonium hydroxides are choline hydroxide and dimethyldipropyl ammonium hydroxide.

  The composition may additionally contain water as some of the components of the stripper solution may be provided as an aqueous solution. The solution may contain 1% by weight, or 2% by weight, or more than 3% by weight of water. In other embodiments, the solution may contain water in the range of about 1 wt% or about 2 wt% or about 3 wt% to about 7 wt% or about 8 wt%.

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

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

  Preferred alkanolamines have at least two carbon atoms and have amino and hydroxyl substituents on different carbon atoms. Examples of suitable alkanolamines include ethanolamine, N-methyl ethanolamine, N-ethyl ethanolamine, N-propyl ethanolamine, N-butyl ethanolamine, diethanolamine, triethanolamine, N-methyl diethanolamine, N-ethyl Diethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, N-methylisopropanolamine, N-ethylisopropanolamine, N-propylisopropanolamine, 2-aminopropan-1-ol, N-methyl-2-aminopropane-1 -Ol, N-ethyl-2-aminopropan-1-ol, 1-aminopropan-3-ol, N-methyl-1-aminopropan-3-ol, N-ethyl-1-ol Minopropan-3-ol, 1-aminobutan-2-ol, N-methyl-1-aminobutan-2-ol, N-ethyl-1-aminobutan-2-ol, 2-aminobutan-1-ol, N-methyl- 2-aminobutan-1-ol, N-ethyl-2-aminobutan-1-ol, 3-aminobutan-1-ol, N-methyl-3-aminobutan-1-ol, N-ethyl-3-aminobutane-1-ol -Ol, 1-aminobutan-4-ol, N-methyl-1-aminobutan-4-ol, N-ethyl-1-aminobutan-4-ol, 1-amino-2-methylpropan-2-ol, 2-amino -2-Methylpropan-1-ol, 1-aminopentan-4-ol, 2-amino-4-methylpentan-1-ol, 2-aminohexane 1-ol, 3-aminoheptane-4-ol, 1-aminooctan-2-ol, 5-aminooctan-4-ol, 1-aminopropane-2,3-diol, 2-aminopropane-1,3 -Diols, tris (oxymethyl) aminomethane, 1,2-diaminopropan-3-ol, 1,3-diaminopropan-2-ol, and 2- (2-aminoethoxy) ethanol. It is not limited to

  If a secondary solvent is used, this is about 0.2% to about 35%, or about 0.2% to about 30%, or about 0.2% to about 25%, or about 0. It may comprise 2% to about 20%, or about 0.2% to about 15%, or about 0.2% to about 12%, or about 5% to about 12%. The secondary solvent can comprise an alcohol, or a polyhydroxyl compound, or a combination of two or more of these.

  The secondary solvents alcohol and polyhydroxyl compounds have two or more hydroxyl groups and do not contain ester, amine or ether groups. Alcohols and polyhydroxyl compounds may be aliphatic, alicyclic, cyclic or aromatic, but desirably aliphatic or alicyclic. The alcohol or polyhydroxyl compound may be saturated or unsaturated, desirably has 1 or less unsaturated bonds, or has no unsaturated bond. The alcohol or polyhydroxyl compound desirably does not contain heteroatoms. The alcohol or polyhydroxyl compound desirably contains only carbon, oxygen and hydrogen atoms.

  Examples of secondary solvent alcohols include linear and branched and aromatic alcohols. For example, the alcohol of the solution may be methanol, ethanol, propanol, isopropyl alcohol, butanol, tert-butyl alcohol, tert-amyl alcohol, 3-methyl-3-pentanol, 1-octanol, 1-decanol, 1-undecanol, 1 -Dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 9-hexadecen-1-ol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1 -Eicosanol, 1-Heneicosanol, 1-docosanol, 13-docosene-1-ol, 1-tetracosanol, 1-hexacosanol, 1-heptacosanol, 1-octacosanol, 1-triacontanol, 1- Dotria contanol 1-tetra triacontanol may include cetearyl alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol. In one example, the solution can include one or more of furfuryl alcohol, tetrahydrofurfuryl alcohol, tert-butyl alcohol, or 3-methyl-3-pentanol.

  As mentioned above, the secondary solvent may be a polyhydroxy compound having two or more hydroxyl groups. The polyhydroxyl compound desirably has a molecular weight of 500 or less, 400 or less, 350 or less, 300 or less, 300 or less, 275 or less, 250 or less, 225 or less, 200 or less, 175 or less, 150 or less, or 125 or less Or 100 or less, or 75 or less.

  The polyhydroxyl compounds as secondary solvents are 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, 1,2,4 5-pentanetriol, 1,3,5-pentanetriol, ethohexadiol, p-methane-3,8-polyhydroxy Compound, 2-methyl-2,4-pentanediol, 2,2-dimethyl-1,3-propanediol, glycerin, trimethylolpropane, 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, hydroxypivalylhydroxypivalate, 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-benzenedimethanol, hydrogenated bisphenol A, 1,1,1-trimethylolpropane, 1,2 It is possible to include 1,1-trimethylolethane, pentaerythritol, erythritol, threitol, dipentaerythritol, sorbitol and the like, and combinations of two or more of the above polyhydroxyl compounds.

  In one example, the solution comprises ethylene glycol, 1,2-propanediol (propylene glycol), 1,3-propanediol, 1,4-pentanediol, 1,2-butanediol, or 1,3-butanediol One or more of the following polyhydroxyl solvents can be included.

  The composition may also optionally contain one or more corrosion inhibitors. Examples of 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; Benzotriazoles; sugar alcohols such as glycerol and sorbitol; carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, benzoic acid, phthalic acid 1,2,3-benzenetricarboxylic acid, glycolic acid, lactic acid, malic acid, citric acid, acetic anhydride, phthalic anhydride, maleic anhydride, maleic anhydride, succinic anhydride, salicylic acid, gallic acid, gallic acid esters such as methyl gallate Propyl gallate; metal salts such as copper (II) nitrate; copper (II) bromide; copper (II) chlorate; copper (II) chloride; copper (II) fluorosilicate; copper (II) formate; copper (II) Selenates; copper (II) sulfates; organic salts of the above carboxyl-containing organic compounds, basic substances such as ethanolamine, trimethylamine, diethylamine, and pyridine such as 2-aminopyridine and the like, and chelate compounds such as 1 And phosphoric acid chelate compounds including 2-propanediamine tetramethylene phosphonic acid and hydroxyethane phosphonic acid, carboxylic acid chelate compounds such as ethylene diamine tetraacetic acid and its sodium and ammonium salts, dihydroxyethyl glycine and nitrilo triol Acid, amine chelate compounds, for example bipyridine, tetraphenylporphyrin and phenanthroline, and oxime-based chelate compounds, for example, dimethylglyoxime and diphenyl glyoxime and the like, but is not limited to such. A single corrosion inhibitor may be used, or a combination of corrosion inhibitors may be used. Corrosion inhibitors have been found to be useful at levels of about 1 ppm to about 10%. In one embodiment, the solution comprises about 0.05 weight percent to about 7 weight percent of a first corrosion inhibitor and about 0.001 weight percent to about 3 weight percent of a second corrosion inhibitor. You may In other embodiments, the solution comprises at least 0.05 weight percent, or at least 0.1 weight percent, or at least 1 weight percent, and / or less than about 3 weight percent, and / or less than about 7 weight percent of the first May contain a corrosion inhibitor of In other embodiments, the solution is at least 0.001 weight percent, or at least 0.01 weight percent, or at least 0.1 weight percent, and / or less than about 1 weight percent, and / or less than about 2 weight percent, And / or may contain less than about 3 percent by weight of a second corrosion inhibitor. The first and second corrosion inhibitors are not the same. Both the first and second corrosion inhibitors can be selected from the above-mentioned corrosion inhibitors. In one embodiment, the one or more corrosion inhibitors are copper (II) nitrate, copper (II) bromide, copper (II) chlorate, copper (II) chloride, copper (II) fluorosilicate, copper II) The formate, copper (II) selenate, and / or copper (II) sulfate may be included alone or in combination with at least one of the above mentioned corrosion inhibitors. In another embodiment, the one or more corrosion inhibitors are copper (II) nitrate, copper (II) bromide, copper (II) chlorate, copper (II) chloride, copper (II) fluorosilicate, copper II) It may be formate, copper (II) selenate, copper (II) sulfate and / or resorcinol. In another preferred embodiment, the corrosion inhibitor may comprise copper (II) nitrate and resorcinol.

  Also, the stripping formulation contains any one or more surfactants, typically at levels ranging from about 0.01% to about 3% or about 0.01 to about 1% by weight. It can also be done. Preferred optional surfactants include fluorosurfactants. Examples of preferred fluorosurfactants are: DuPont FSO (polyethylene glycol (50%), ethylene glycol (25%), 1,4-dioxane (<0.1%), fluorinated telomer B containing 25% water) Monoether). Another example of a preferred fluorosurfactant is DuPont, Capstone, FS-10 (30% perfluoroalkyl sulfonic acid in water).

  While a temperature of at least 50 ° C. is preferred for contacting the substrate, a temperature of about 50 ° C. to about 75 ° C. is more preferred for most applications. Lower contact temperatures are appropriate for certain applications where the substrate is highly sensitive or longer removal times are required. For example, when reworking the substrate, it may be appropriate to maintain the stripper solution at a temperature of at least 20 ° C. for a longer period of time to remove the photoresist and avoid damage to the substrate.

  When immersing the substrate, agitation of the composition further promotes photoresist removal. Agitation can be effected by mechanical agitation, circulation or by bubbling an inert gas through the composition. Once the desired amount of photoresist has been removed, the substrate is removed from contact with the stripper solution and rinsed with water or alcohol. DI water is the preferred form of water and isopropanol is the preferred alcohol. In the case of a substrate having components to be oxidized, the rinsing is preferably performed under an inert atmosphere. Preferred stripper solutions according to the present disclosure have improved retention capabilities for photoresist materials as compared to current commercial products, and can process a larger number of substrates at a given stripper solution volume. it can.

  The stripper solution provided in the present disclosure can be used to remove a polymeric resist material present in a single layer resist or a particular type of bilayer resist. For example, a bilayer resist can typically have a first inorganic layer covered by a second polymer layer or can have two polymer layers. The method taught below can be used to effectively remove the polymer resist monolayer from a standard wafer having a single polymer layer. The same method can also be used to remove a single polymer layer from a wafer having two layers consisting of a first inorganic layer and a second or outer polymer layer. Finally, two polymer layers can be effectively removed from a wafer having two layers consisting of two polymer layers.

  The present disclosure describes the chemical solution used to remove thick photoresist, which is about 10 μm to about 200 μm or more, or about 15 μm to about 20 μm or more in advanced packaging applications for semiconductor devices. The resist may be 200 μm, or about 20 μm to about 200 μm. In other cases, the chemical solution may be used to remove about 1 μm to about 200 μm or more, or about 2 μm to 200 μm, or about 3 μm to about 200 μm of photoresist. In one embodiment, the described solution contains 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 essentially free of TMAH. The quaternary ammonium hydroxide is preferentially either choline hydroxide or dimethyldipropyl ammonium hydroxide. By "essentially free" is meant an amount of less than 1 percent, alternatively less than 0.1 percent, alternatively less than 0.01 percent, or less than 0.001 percent. Also, "essentially free" includes the absence of TMAH. In a further embodiment, the quaternary ammonium hydroxide does not comprise TMAH. The solution also optionally contains a surfactant. The solution may contain more than 1 or 3% by weight of water. In one embodiment, the solution may contain 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, about 1.5, about 1.8, about 1.8, about 2.0, about More than 2.2 and / or more than about 2.5. In another embodiment, the ratio of the amount of water to the amount of quaternary ammonium hydroxide in the solution is about 1.2 to about 1.5. The solution may contain more than 25% by weight MEA.

  Some embodiments of the composition according to the invention are: nitrogen-containing solvents, bis-choline salts, tri-choline salts, oxoammonium compounds, hydroxyamines and their derivatives, methyldiethanolamine, aminoethylethanol Amine, glycol ether, hydrogen peroxide, oxidant, organic acid, inorganic acid, inorganic base, metal hydroxide, glycol, polyol, NMP, surfactant, metal-containing compound, sugar alcohol, and aromatic hydroxyl compound, and these One or more of any combination of, or none may be essentially included or not included in any combination (these terms are defined above). In another embodiment, the composition consists essentially of sodium and / or calcium and / or aminocarboxylic acid and / or alcohol and / or ethylenediamine and / or ethylene triamine and / or thiophenol There will be no (or no). In some embodiments, the compositions disclosed herein are essentially free or not at least one of the following compounds: alkyl thiols, and organosilanes Formulated as. In some embodiments, the compositions disclosed herein are essentially free of, or essentially free of, one or more of the following: halide-containing compounds Formulated so that, for example, the composition is essentially free or not containing one or more of the following: fluoride, bromine, chlorine or iodine containing compounds It is formulated. In another embodiment, the composition may be essentially free or free of sulfonic acid and / or phosphoric acid and / or sulfuric acid and / or nitric acid and / or hydrochloric acid. In another embodiment, the composition may be essentially free or free of sulfate and / or nitrate and / or sulfite and / or nitrite. In another embodiment, the composition comprises ethyl diamine, a sodium containing compound, and / or a calcium containing compound, a manganese containing compound, or a magnesium containing compound, and / or a chromium containing compound, and / or a sulfur containing compound, and / or It may or may not be essentially free of silane containing compounds and / or phosphorus containing compounds. Some embodiments may be essentially free of surfactants or not. Some embodiments are essentially free of amphoteric salts, cationic surfactants, and / or anionic surfactants, and / or zwitterionic surfactants, and / or nonionic surfactants. Good or not included. Some embodiments may be essentially free or not include imidazole and / or anhydride. Some embodiments may or may not be essentially free of pyrrolidone and / or acetamide. Some embodiments may or may not be essentially free of any amine. Some embodiments may be essentially free of or include peroxy compounds, and / or peroxides, and / or persulfates, and / or percarbonates, and their acids, and their salts. It is not necessary. Some embodiments are iodate and / or perborate and / or borate and / or percarbonate and / or peroxy acid and / or cerium compounds and / or cyanide, and It may or may not be essentially free of / or periodic acid and / or ammonium molybdate and / or ammonia. The components that may not be included in the compositions of the present invention may be any combination of components, as if all of the combinations were as specified herein.

  The composition of the present invention may also contain one or more of the following additives: chelating agents, chemical modifiers, dyes, biocides, and other additives. Additives may be added, typically in amounts up to about 5% by weight of the total of the composition, to the extent that they do not adversely affect the performance of the composition. In other embodiments, the composition may be essentially free of, or free of, chelating agents, dyes, biocides, and / or other additives.

  In Example 1, the thick spin-on photoresist was removed from a silicon wafer plated with Cu pillars and capped with Sn / Ag solder using various stripping compositions. Resist removal was performed using a dip process in a beaker.

  Specimen size semiconductor wafer samples were processed in a beaker for the immersion process. The beaker was filled with 100 mL of stripping composition and heated to a target temperature of 70.degree. When the stripping composition was at the target temperature, the test piece was placed in a holder in a beaker and slight agitation was added with a stir bar. The temperature was maintained at the target temperature of 70 ° C. throughout the process. After a total treatment time of 60 minutes, the coupons were removed from the beaker, rinsed with DI water and IPA, and dried in a stream of air.

  Resist removal was observed and recorded based on the following tests. Resist removal is defined as "clean" when all the resist is removed from the wafer specimen surface, and when at least 95% of the resist but not all of the resist is removed from the surface. Defined as "mostly clean" and as "partially clean" if at least about 80% of the resist but less than 95% of the resist is removed from the surface.

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

  Table 1 lists various stripping compositions of the present invention and comparative stripping compositions.

  Example 1

  Table 2 lists the stripping compositions tested for Example 1 using a dipping process and a semiconductor wafer having a thick photoresist with plated Cu pillars and Sn / Ag solder caps. The heating temperature and time for all compositions in Table 2 were 70 ° C. and 60 minutes, respectively.

  In Example 2, a 40 μm thick negative dry film photoresist was removed from a silicon wafer plated with Cu features using various stripping compositions. Resist removal was performed using a dip process in a beaker.

  Specimen size semiconductor wafer samples were processed in a beaker for the immersion process. The beaker was filled with 100 mL of stripping composition and heated to a target temperature of 70.degree. When the stripping composition was at the target temperature, the test piece was placed in a holder in a beaker and slight agitation was added with a stir bar. The temperature was maintained at the target temperature of 70 ° C. throughout the process. After a total treatment time of 30 to 60 minutes, the coupons were removed from the beaker, rinsed with DI water and IPA, and dried in a stream of air.

  Resist removal was observed and recorded based on the following tests. Resist removal is defined as "clean" when all the resist is removed from the wafer specimen surface, and when at least 95% of the resist but not all of the resist is removed from the surface. Defined as "mostly clean" and as "partially clean" if at least about 80% of the resist but less than 95% of the resist is removed from the surface.

  Example 2

  Table 3 lists the stripping compositions tested for Example 2 using a dipping process and a semiconductor wafer having a thick dry film photoresist with plated Cu features. The heating temperature in Table 3 was 70.degree.

  Example 3

  In Example 3, various stripping compositions were used to evaluate metal corrosion. The metal corrosion test was conducted using a dip process in a beaker.

  For the immersion process, a specimen size semiconductor wafer sample containing a Cu layer of known thickness and a specimen size semiconductor wafer sample containing a Sn layer of known thickness were processed in a beaker. Layers of Cu and Sn thickness were deposited on the wafer by physical vapor deposition. The beaker was filled with 100 mL of stripping composition and heated to a target temperature of 70.degree. Once the stripping composition was at the target temperature, test pieces of the sample having the respective metals on and having a known surface area were placed in the holder in the beaker and agitation was added by means of a stir bar. The temperature was maintained at the target temperature of 70 ° C. throughout the process. After a total treatment time of 60 or 120 minutes, the specimens were removed from the beaker.

  Solution samples were collected and the concentrations of dissolved Cu and Sn were measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The concentrations of dissolved Cu and Sn were also measured in solution samples taken as controls before the solution was heated and used to process the test specimens. Changes in the concentration of dissolved Cu and Sn indicated the amount of metal dissolved by the formulation during the specimen cleaning process. The small change of the concentration of dissolved metal to 10 ppm or less relative to the control level indicates very good metal compatibility, ie, a low metal etching rate.

  Table 4 shows the ICP-AES measurements of Example 3 for the concentrations of dissolved Cu and Sn using a dip process. The amounts of Cu and Sn controls are shown in columns 3 and 4 of Table 4 respectively, and the measured amounts are shown in the next four columns displayed. A concentration of 10 ppm or less for the control is preferred for the 0 ppm target. The heating temperature of all the compositions in Table 4 was 70 ° C., and the treatment time was 60 minutes and 120 minutes, respectively. The amount of Cu or Sn dissolved (removed from the wafer specimen) by the stripper solution can be determined by subtracting the amount of control from the measured amount. For example, for Formulation 1, 2 ppm (2 ppm minus 0 ppm) of Cu is dissolved by the stripper solution at 70 ° C. and 60 minutes, and 3.8 ppm (4.3 ppm minus 0.5 ppm) of Sn is stripped at 70 ° C. and 60 minutes It was dissolved by the solution.

  Table 5 shows the freezing points of the various formulations, with lower temperatures being preferred for improved storage and transport capabilities.

  Example 4

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

  Table 6 shows the change in base level measured by acid-base titration in mass% at each target interval up to 8 hours. It is preferred that the percent change in mass per target interval be small, indicating a more stable formulation. Improved formulation stability provides the user with longer product storage times, longer product bath life in use, and improved photoresist retention capacity. The change in mass% of base over 0-8 hours is reported in the last row of the table, which indicates that the change in formulation 10 was minimal.

  The invention has been described with reference to one or more embodiments. It will be apparent to those skilled in the art that various modifications can be made without departing from the scope of the present invention and equivalents could be substituted for that element. In addition, numerous modifications can be made to adapt the specific context or materials to the teachings of the present invention without departing from the essential scope of the present invention. Accordingly, the present invention is not to be limited to the specific embodiments disclosed in the best mode contemplated for carrying out the invention, but rather any embodiments within the scope of the appended claims. It shall include an aspect. In addition, any numerical values specified in the detailed description shall be interpreted as if both exact and approximate values are explicitly stated. Furthermore, whenever the term "having," "comprising," "containing," or the like is used in the specification and claims, this term refers to the narrower descriptor " As if "consisting essentially of" and "consisting of" consisted of "includes", "contains" or "likes" followed by another option Contains these descriptors. In addition, when the article "a" or "an" or "the" is used to describe any of the components of a stripper composition, this is any where it appears in the specification and claims. It should be interpreted as if these articles were replaced by "one or more".

Claims (20)

Stripper solution for removing photoresist from a substrate,
About 20% by weight to about 90% by weight of dimethyl sulfoxide,
About 1 wt% to about 7 wt% quaternary ammonium hydroxide,
About 1% to about 75% by weight alkanolamine,
About 0.001% to about 7% by weight of a corrosion inhibitor, and
About 1% by weight to about 8% by weight water,
Including
The freezing point of the solution is less than about 0 ° C., and the quaternary ammonium hydroxide is essentially free of tetramethyl ammonium hydroxide;
solution. The quaternary ammonium hydroxide _has a _(C 1 -C ₈₎ alkyl, arylalkyl, _{benzyl, (C} 1 -C ₅₎ alcohols, and substituted groups which are combinations of these, a solution according to claim 1 .   The solution according to claim 2, wherein the quaternary ammonium hydroxide comprises at least one of choline hydroxide, tri (2-hydroxyethyl) methyl ammonium hydroxide, or dimethyl dipropyl ammonium hydroxide.   The solution of claim 1, wherein the alkanolamine is present in an amount of about 25% to about 75% by weight.   5. The solution of claim 4, wherein the alkanolamine comprises monoethanolamine. The dimethyl sulfoxide is present in an amount of about 55% to about 60% by weight,
Said quaternary ammonium hydroxide is present in an amount of about 1.5% to about 3.5% by weight;
The alkanolamine is present in an amount of about 30% to about 40% by weight, and the first corrosion inhibitor is present in an amount of about 0.001% to about 3% by weight.
The solution according to claim 4.   7. The solution of claim 6, wherein the alkanolamine comprises monoethanolamine.   The solution according to claim 7, wherein the first corrosion inhibitor is selected from the group consisting of resorcinol, glycerol, sorbitol, and copper (II) nitrate.   The first corrosion inhibitor is copper (II) nitrate, copper (II) bromide, copper (II) chlorate, copper (II) chloride, copper (II) fluorosilicate, copper (II) formate, copper (II) A solution according to claim 7, selected from the group consisting of selenate and / or copper (II) sulfate and resorcinol.   9. The solution of claim 8, wherein the first corrosion inhibitor is present in an amount of about 0.001 wt% to about 0.1 wt%.   The solution of claim 1, further comprising about 0.01 wt% to about 3 wt% surfactant.   The solution according to 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 about 0.001 wt% to about 3 wt% of a second corrosion inhibitor.   14. The solution according to claim 13, wherein said second corrosion inhibitor is different from said first corrosion inhibitor and is selected from the group consisting of resorcinol, glycerol, sorbitol, and copper (II) nitrate. .   The dimethylsulfoxide is present in an amount of about 35% to about 45% by weight, and the quaternary ammonium hydroxide is present in an amount of about 1.5% to about 3.5% by weight; the alkanolamine Is present in an amount of about 50% to about 60% by weight, the first corrosion inhibitor is present in an amount of about 0.05% to about 3% by weight, and the second corrosion inhibitor 15. The solution of claim 14, wherein the agent is present in an amount of about 0.001 wt% to about 0.1 wt%.   16. The solution of claim 15, wherein the alkanolamine comprises monoethanolamine.   The solution of claim 1, wherein the freezing point is less than about -15 ° C.   The solution of claim 1, wherein the freezing point is less than about -21 ° C. Stripper solution for removing photoresist from a substrate,
About 20% by weight to about 90% by weight of dimethyl sulfoxide,
About 1 wt% to about 7 wt% quaternary ammonium hydroxide,
About 1% to about 75% by weight alkanolamine,
About 0.001% to about 7% by weight of a corrosion inhibitor, and
Contains water,
The ratio of the amount of water to the amount of said quaternary ammonium hydroxide is greater than about 1.2,
The freezing point of the solution is less than about 0 ° C., and the quaternary ammonium hydroxide is essentially free of tetramethyl ammonium hydroxide;
solution. A method of removing a resist from a substrate,
Contacting the resist on a substrate with a stripping solution for a time sufficient to remove a desired amount of resist, and removing the substrate from the stripping solution, the stripping solution comprising
About 20% by weight to about 90% by weight of dimethyl sulfoxide,
About 1 wt% to about 7 wt% quaternary ammonium hydroxide,
About 1% to about 75% by weight alkanolamine,
About 0.001% to about 7% by weight of a corrosion inhibitor, and
About 1% by weight to about 8% by weight water,
Including
The freezing point of the solution is less than about 0 ° C., and
Said quaternary ammonium hydroxide is essentially free of tetramethyl ammonium hydroxide,
Method.