DMSO-free photoresist stripping solution for removing thick photoresist

Abstract

A photoresist stripping composition for removing photoresist material from a substrate, the photoresist stripping composition comprising N-Formylmorpholine (NFM) as solvent, a first stripping component consisting of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group and a second stripping component consisting of one or more compounds selected from the group consisting of lactones, lactams and amides or consisting of one or more compounds selected from the group consisting of heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups, and ureas, wherein the photoresist stripping composition is free of N-Methyl-2-pyrrolidone (NMP), Tetramethyl- ammonium hydroxide (TMAH) and dimethyl sulfoxide (DMSO).

Description

[0001] BASF SE

[0002] Carl-Bosch-StraBe 38, 67056 Ludwigshafen am Rhein

[0003] Germany

[0004] DMSO-free photoresist stripping solution for removing thick photoresist

[0005] FIELD OF THE INVENTION

[0006] The present invention relates to a photoresist stripping composition for removing photoresist material from a substrate, the photoresist stripping composition comprising N-Formylmorpholine (NFM) as solvent, a first stripping component consisting of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group, and a second stripping component consisting of one or more compounds selected from the group consisting of lactones, lactams and amides or consisting of one or more compounds selected from the group consisting of heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups, and ureas, wherein the photoresist stripping composition is free of N-Methyl-2-py rrolidone (NMP) and Tetramethylammonium hydroxide (TMAH) and dimethyl sulfoxide (DMSO). The present invention also relates to the use of said photoresist stripping composition for removing photoresist material from a substrate; the use of 2-[2-(Dimethylamino)ethoxy]ethanol and / or 2-Di-methylamino-2-methylpropan-1-ol as compound in a photoresist stripping composition comprising N-Formylmorpholine (NFM); and a process of removing photoresist material from a substrate.

[0007] BACKGROUND OF THE INVENTIONBASF SE

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[0011] 240899 WO01

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[0013] The fabrication of integrated circuits, also known as a microchips or simply chips, is a complex process that involves the use of photolithography to transfer intricate geometric patterns onto a substrate. These patterns, which are formed on or within a semiconductor substrate, play a crucial role in enabling the integration of dopants, electrical properties, and wires to create functional circuits with specific technological purposes.

[0014] During the photolithography process, a thin film of photoresist is applied to the substrate. This photoresist layer is then exposed to light through a photomask, which contains clear and opaque features that define the desired pattern. The areas of the photoresist that are exposed to light become either soluble or insoluble in a developer solution. If the exposed regions of the photoresist become soluble, a positive image of the photomask is created in the photoresist. This type of photoresist is known as a positive photoresist. On the other hand, if the unexposed areas are dissolved by the developer, a negative image is formed in the photoresist, resulting in a negative photoresist. After the development process, the areas of the substrate that are no longer covered by the photoresist need to be replicated according to the pattern defined by the photomask. This is achieved through etching, where the exposed regions of the substrate are selectively removed to match the mask pattern.

[0015] Once the etching process is complete, the remaining photoresist is no longer necessary and must be removed from the substrate. This is typically done through a wet stripping process, where a photoresist stripping composition is used to chemically alter the photoresist and make it no longer adhere to the substrate.

[0016] A variety of photoresist stripping compositions have been suggested for the stripping process, and particularly, photoresist stripping compositions comprising N-Methyl-2-pyrrolidone (NMP), tetramethylammonium hydroxide (TMAH) and / or dimethyl sulfoxide (DMSO) are commonly used.

[0017] For example WO 2019145312 A1 discloses photoresist remover compositions comprising N-Methyl-2-pyrrolidone (NMP).

[0018] JP 2023139696 A, US 10,731,114 B2 and US 10,866,518 B2 disclose photoresist stripping compositions comprising dimethyl sulfoxide (DMSO).

[0019] US 2023 / 03 17647 A1 discloses a photoresist stripping composition comprising tetramethylammonium hydroxide (TMAH).BASF SE

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[0025] WO 2023 / 140345 A1 discloses a photoresist stripping composition, wherein the composition comprises a quaternary ammonium hydroxide, in particular comprises tetramethylammonium hydroxide (TMAH).

[0026] ON 101026108 A discloses a method for forming a pre-solder of a circuit substrate wherein the patterned photoresist layer is removed by N-Methyl-2-pyrrolidone (NMP).

[0027] JP 4474776 B2 and JP 2012018982 A disclose a resist stripper containing N-Methyl-2-pyrrolidone (NMP).

[0028] Other relevant documents are:

[0029] JP 2023 / 107076 A which relates to photoresist stripping compositions.

[0030] WO 2024 / 250131 A1 which pertains to COMPOSITIONS CONTAINING N-SUBSTITUTED PIPERAZINES FOR ELECTRONIC MANUFACTURING APPLICATIONS.

[0031] US 6,586,164 B2 which is directed toward effective photoresist stripping compositions that are less corrosive and do not cause skin irritation.

[0032] US 2025 / 0060675 A1 which is directed to a photoresist stripper composition and a method for forming (or providing) a pattern utilizing the same, and for example, to a photoresist stripper composition for removing photoresist and a method for forming (or providing) a pattern utilizing the same.

[0033] However, compounds such N-methyl-2-pyrrolidone (NMP), tetramethylammonium hydroxide (TMAH) etc., have high toxicity, reproductive toxicity and / or are environmental hazardous. For example, NMP is listed in the Substance of Very High Concerns (SVHC) registry of the European Globally Harmonized System of Classification and Labelling of Chemicals (GHS) and REACH which lists the restrictions on the manufacture, placing on the market and use of certain dangerous substances, mixtures and articles. Photoresist stripping composition up to today are in most cases not free of Substances of Very High Concern (SVHC) and do not allow for practical handling, thus not fulfilling the requirements for commercialisation.

[0034] The commonly used solvent dimethyl sulfoxide (DMSO) also has certain disadvantages. Although not being harmful itself DMSO is a very good solvent able to dissolve an enormous catalogue ofBASF SE

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[0040] polar and nonpolar small molecules. Furthermore DMSO can effectively penetrate the skin. Accordingly, DMSO may unintentionally transport harmful chemicals through the skin barrier which can cause severe damages.

[0041] Accordingly, the development of non-toxic, easy to handle and eco-friendly alternatives to such photoresist stripping compositions has drawn a lot of attention lately. It is an urgent request from electronic processing customers that such green alternatives are provided, ideally the alternatives should be free of DMSO for the reasons set forth above.

[0042] Correspondingly, some photoresist stripping compositions without the presence of N-methyl-2-pyrrolidone (NMP) or tetramethylammonium hydroxide (TMAH) have been suggested, e.g. in US 10,731,114 B2 and US 10,866,518 B2. However, these alternative photoresist stripping compositions still rely on the use of dimethyl sulfoxide (DMSO) as solvent.

[0043] Furthermore, it is still important that so-called eco-friendly or green photoresist stripping compositions with a beneficial health and environmental profile and free of DMSO achieve a similar or even better performance than those photoresist stripping compositions which rely on the use of N-methyl-2-pyrrolidone (NMP), tetramethylammonium hydroxide (TMAH) or DMSO.

[0044] Besides having an excellent photoresist strippability it is also important that said photoresist stripping composition does not erode, etch, chemically alter or otherwise negatively affect the substrate itself. In particular the photoresist stripping composition should be compatible with metallic substrate surfaces as present in integrated circuits and intermediate products within the production process of integrated circuits. I.e., the photoresist stripping composition should not substantially etch, alter or otherwise negatively affect a metal surface comprising or consisting of copper, aluminium, tungsten, cobalt, nickel, tin, silver and / or molybdenum or any combination thereof. In particular the photoresist stripping composition should not erode copper which is widely used in integrated circuits.

[0045] Accordingly, there is a high demand for green and DMSO free photoresist stripping compositions that selectively remove photoresist material from a substrate surface without substantially etching, altering or otherwise negatively affecting the substrate.

[0046] SUMMARY OF THE INVENTIONBASF SE

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[0052] Accordingly, it was a first object of the present invention to provide for such an improved photoresist stripping composition featuring a beneficial health and environmental profile, being free of DMSO and at the same time allowing for a good or even better stripping (cleaning) ability for photoresist removal. The improved photoresist stripping composition should preferably be free of Substances of Very High Concern (SVHC) according to the REACH classification and / or free of any substance which is classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) and / or hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024.

[0053] It was a further object of the present invention to provide for an improved photoresist stripping composition which selectively removes photoresist material, in particular positive photoresist material, from a substrate surface without substantially etching, altering or otherwise negatively affecting the substrate itself. The improved photoresist stripping composition should in particular not substantially change the metal surface of the substrate which is typically used or present in integrated circuits.

[0054] It was another object of the present invention to provide for a facile and economic use of said photoresist stripping composition for removing photoresist material from a substrate.

[0055] It was a further object of the present invention to provide for a facile and economic process of removing photoresist material from a substrate and / or to provide for a facile and economic process for the production of an integrated circuit, comprising said process of removing photoresist material from a substrate.

[0056] The invention is defined in the claims as attached.

[0057] The present invention concerns in its categories a photoresist stripping composition for removing photoresist material from a substrate, the use of 2-[2-(Dimethylamino)ethoxy]ethanol and / or 2-Di-methylamino-2-methylpropan-1-ol as compound in a photoresist stripping composition comprising N-Formylmorpholine (NFM), the use of a photoresist stripping composition for removing photoresist material from a substrate, a process of removing photoresist material from a substrate and a process for the production of an integrated circuit. Embodiments, aspects or features disclosed for or in connection with one of these categories in each case analogously apply for the other categories of the invention.BASF SE

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[0063] If not stated otherwise, preferred embodiments, aspects or features of the present invention can be combined with other embodiments, aspects or features, especially with other preferred embodiments, aspects or features, irrespectively of the categories to which the embodiments, aspects or features relate. The combination of preferred embodiments, aspects or features with other preferred embodiments, aspects or features in each case again results in preferred embodiments, aspects or features.

[0064] In accordance with the object(s) of the invention as stated above, the present invention relates to a photoresist stripping composition for removing photoresist material from a substrate, the photoresist stripping composition comprising or consisting of

[0065] - N-Formylmorpholine (NFM) as solvent,

[0066] N-Formylmorpholine (NFM) being present in a concentration of 15 wt.% to 85 wt.% in the photoresist stripping composition,

[0067] and

[0068] - a first stripping component consisting of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group,

[0069] the first stripping component being present in a concentration of 3 wt.% to 50 wt.% in the photoresist stripping composition,

[0070] and

[0071] - a second stripping component consisting of one or more compounds selected from the group consisting of lactones, lactams and amides, or consisting of one or more compounds selected from the group consisting of heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups, and ureas,

[0072] the second stripping component being present in a concentration of 5 wt.% to 60 wt.% in the photoresist stripping composition,

[0073] wherein the photoresist stripping composition is free of N-Methyl-2-pyrrolidone (NMP), Tetramethylammonium hydroxide (TMAH) and dimethyl sulfoxide (DMSO).BASF SE

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[0079] Preferred is a photoresist stripping composition according to the present invention, wherein the photoresist stripping composition is essentially free, preferably is completely free, of any quaternary ammonium compounds, in particular quaternary ammonium hydroxides.

[0080] In contrast to most state of the art photoresist stripping compositions, as inter alia proposed in WO 2023 / 140345 A1, ON 101026108 A, JP 4474776 B2 or JP 2012018982 A, the photoresist stripping composition according to the present invention does not rely on toxic or otherwise harmful chemical compounds such as the widely used quaternary ammonium compounds like tetramethylammonium hydroxide (TMAH) or tetraethylammonium hydroxide (TEAH) and N-Methyl-2-pyrrolidone (NMP).

[0081] Preferred is a photoresist stripping composition according to the present invention, wherein the photoresist stripping composition is essentially free, preferably is completely free, of any amines classified as acute toxic, category 1 to 3 (GHS06) or health hazardous, category 1, 1A, 1B (GHS08) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024, in particular free of diethylentriamine, triethylenetetramine, N,N,N',N'-Tetramethyl-1 ,6-hexanediamine and tetraethylenepentamine (TEPA).

[0082] More preferred is a photoresist stripping composition according to the present invention, wherein the photoresist stripping composition is essentially free, preferably is completely free of any substance which is classified as acute toxic, category 1 to 3 (GHS06) or health hazardous, category 1, 1A, 1B (GHS08) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024, more preferably the photoresist stripping composition is also essentially or completely free of any substance which is classified as hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024.

[0083] Also preferred is a photoresist stripping composition according to the present invention, wherein the photoresist stripping composition is essentially free, preferably is completely free of any Substances of Very High Concern (SVHC) according to the REACH classification.

[0084] Accordingly, the inventors have identified a yet unknown photoresist stripping composition which fulfils the high health related and environmental standards and which can be classified as green or eco-friendly and which does not rely on the use of dimethyl sulfoxide (DMSO).BASF SE

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[0090] The inventors of the present invention have found that a photoresist stripping composition as defined herein is advantageously able to selectively remove photoresist material from a substrate.

[0091] The photoresist stripping composition according to the present invention comprises or consists of readily available and easy to handle compounds such as N-Formylmorpholine (NFM), alkanolamines featuring a tertiary amino group, lactones, lactams, amides, heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups, and ureas. The main components of the photoresist stripping composition are easily miscible in a wide variety of ratios. The photoresist stripping composition according to the present invention can be applied to a wide variety of different substrates, in particular to substrates with a metal surface.

[0092] It has been found that large amounts of water, in particular amounts of more than 30.0 wt.% of water, in the photoresist stripping composition result in substantial damages of metal surfaces, in particular aluminium surface layers. Severe etching of substrate surfaces has been observed even under mild testing conditions (60 °C, immersion time of 15 min). Accordingly, it is preferred that the photoresist stripping composition according to the present invention contains less than 30.0 wt.% of water, preferably less than 20.0 wt.% of water, more preferably less than 10.0 wt.% of water.

[0093] Since the photoresist stripping compositions according to the present invention are also designed to be applied under harsher stripping conditions at elevated temperatures above 60 °C and / or at elongated immersion times of more than 15 minutes, e.g., for removal of very thick photoresist layers with a thickness of more than 100 m, it is further preferred that no water is intentionally added to the photoresist stripping composition, since the presence of water in amounts of greater than 0.1 wt.% or greater than 1 wt.% may already be disadvantageous in terms of metal etching, in particular aluminium etching. Nevertheless small amounts of water within the photoresist stripping composition as e.g. present in the solvents DMSO and / or NFM used for preparing the photoresist stripping composition are tolerable and do in general not negatively affect the stripping performance or the etching rate. Water may also be present as an impurity or a stabilizer associated with the stripping components of the composition or due to hygroscopic compounds within the photoresist stripping composition.

[0094] In a particular preferred embodiment of a photoresist stripping composition according to the present invention the photoresist stripping composition contains less than 10.0 wt.% of water, preferably less than 1.0 wt.% of water, more preferably less than 0.1 wt.% of water.BASF SE

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[0100] In some cases, e.g., when very thin metal layers of only a few nanometer thickness or filigree structures are present on the surface of the target substrate, it is preferred that the photoresist stripping composition according to the present invention is essentially free of water.

[0101] In some cases, e.g., when very thin metal layers of only a few nanometer thickness or filigree structures are present on the surface of the target substrate, it is preferred that the photoresist stripping composition according to the present invention is essentially free of water.

[0102] The photoresist stripping composition according to the present invention is suitable for removal of photoresist material from a substrate. The present invention is not particularly limited to any specific kind of photoresist material or substrate.

[0103] Nevertheless it has been found in thorough investigations that the photoresist stripping composition according to the present invention is particularly suitable for removal of positive photoresist material.

[0104] A photoresist is a light-sensitive material used in several processes, such as photolithography and photoengraving, to form a patterned coating on a surface. This process and thus also photoresist used in that process is crucial in the electronics industry for the production of integrated circuits and other devices. Types of photoresist material are known to the skilled person, usually photoresist material comprises or consists of single- or multi-component (co-)polymers and / or resins.

[0105] The photoresist stripping composition according to the present invention is well suitable to selectively remove positive photoresist material in the form of thermoplastic (co-)polymers used in lithography for the production of integrated circuits. Examples of suitable positive photoresist material are inter alia described in Xu et al., Photoresist chemistry in the semiconductor field, Polymer Journal (2018) 50, 45-55, in particular poly(p-chloromethylstyrene) (PCMS) or (co-)polymers composed of a-gamma butyrolactone methacrylate (GBLMA), methyl adamantyl methacrylate (MAMA) and / or hydroxyl adamantyl methacrylate (HAMA) are suitable positive photoresist materials. Other suitable positive photoresist materials are electron beam lithography resists such as poly methyl methacrylate (PMMA) or a a-chloromethacrylate / o-methylstyrene co-polymer which is inter alia commercially available as ZEP520 from Zeon Chemicals (Japan).

[0106] The photoresist stripping composition according to the present invention can remove layers of photoresist material of varying thickness and has been shown to substantially or completely remove photoresist layers in a thickness of up to 200 pm. The photoresist stripping composition accordingBASF SE

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[0112] to the present invention can remove photoresist material from blanket substrates as well as substrates with pattern masks.

[0113] It has been found in several etching experiments that the photoresist stripping composition according to the present invention selectively removes photoresist material, in particular positive photoresist material, from a substrate surface under mild and easy to handle conditions, without substantially etching, altering or otherwise negatively affecting the substrate itself. Observed etching rates of metal surfaces when immersed into the photoresist stripping composition according to the present invention where below 20 A / min in the case of copper surfaces and below 2 A / min in the case of aluminium, tungsten, cobalt, nickel, tin, silver and molybdenum surfaces. Accordingly, the photoresist stripping composition according to the present invention can advantageously be applied to a wide variety of metal substrates, especially metal substrates commonly used in the production of integrated circuits.

[0114] It has been found in several etching experiments that the photoresist stripping composition according to the present invention achieves good results in terms of photoresist removal from a substrate at beneficially low temperatures in the range of from 20 to 70 °C and in comparatively short process times in the range of from 1 to 20 minutes. Accordingly, the photoresist stripping composition according to the present invention can advantageously be applied in a facile and economic process of removing photoresist material from a substrate which is an important part of the overall production process of an integrated circuit.

[0115] The excellent performance of the photoresist stripping composition according to the present invention in terms of removal of photoresist material from a substrate without negatively effecting the substrate itself is in particular related to the selection of the first stripping component as defined in the claims and as defined and described herein.

[0116] It has been proven particularly suitable and effective when the first stripping component consists of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group, wherein the one or at least one of the more than one alkanolamines featuring a tertiary amino group contains 1 to 6 hydroxy groups and / or has a molar mass in a range from 100 g / mol to 1000 g / mol.BASF SE

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[0122] A good and representative example of such an alkanolamine compound featuring a tertiary amino group is triethanolamine which has shown excellent performance in photoresist removal in a wide variety of tested photoresist stripping compositions as depicted in the example section below.

[0123] Preferred is a photoresist stripping composition according to the present invention, wherein the first stripping component consists of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group, wherein the one or at least one of the more than one alkanolamines featuring a tertiary amino group contains 1 to 6 hydroxy groups, preferably 1 to 5 hydroxy groups, more preferably 1 to 4 hydroxy groups, even more preferably 1 to 3 hydroxy groups.

[0124] Particularly preferred is an alkanolamine featuring a tertiary amino group that contains 3 hydroxy groups such as triethanolamine.

[0125] The hydroxy groups may be present in only one, in two or in all three of the N-substituents of the tertiary amino group. It is preferred that the alkanolamine featuring a tertiary amino group features at least one hydroxy group in all three N-substituents of the tertiary amino group as is the case in triethanolamine.

[0126] Also preferred is a photoresist stripping composition according to the present invention, wherein the first stripping component consists of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group, wherein the one or at least one of the more than one alkanolamines featuring a tertiary amino group has a molar mass in a range from 100 g / mol to 1000 g / mol, preferably in a range from 100 g / mol to 800 g / mol, more preferably in a range from 100 g / mol to 600 g / mol, even more preferably in a range from 100 g / mol to 400 g / mol, most preferably in a range from 100 g / mol to 250 g / mol.

[0127] Similarly preferred is a photoresist stripping composition according to the present invention, wherein the first stripping component consists of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group, wherein the one or at least one of the more than one alkanolamines featuring a tertiary amino group has one tertiary amino group and wherein one, two or three of the N-substituents of said one tertiary amino group are individually and independently selected from the group consisting of

[0128] - linear or branched alkyls, preferably the linear or branched alkyl is methyl, ethyl, propyl, butyl, pentyl or hexyl, more preferably methyl, ethyl, propyl or butyl,BASF SE

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[0134] - linear or branched hydroxyalkyls, preferably the linear or branched hydroxyalkyl is a mono-hydrox-yalkyl, more preferably is hydroxymethyl, hydroxyethyl, hydroxypropyl or hydroxybutyl,

[0135] - linear or branched hydroxyalkylether groups such as ethoxyethanol (-CH2-CH2-O-CH2-CH2-OH).

[0136] For example the three N-substituents of the tertiary amino group as present in an exemplary alkanolamine featuring a tertiary amino group are as follows: two methyl groups (dimethyl) and one ethoxyethanol group (-CH2-CH2-O-CH2-CH2-OH), as is the case for 2-[2-(Dimethylamino)ethoxy]eth-anol.

[0137] In another example the three N-substituents of the tertiary amino group as present in an exemplary alkanolamine featuring a tertiary amino group are as follows: two methyl groups (dimethyl) and one 2-methylpropan-1 -ol group, as is the case for 2-Dimethylamino-2-methylpropan-1-ol.

[0138] In yet another example the three N-substituents of the tertiary amino group as present in an exemplary alkanolamine featuring a tertiary amino group are as follows: three hydroxyethyl groups, as is the case for triethanolamine.

[0139] Particular preferred is a photoresist stripping composition according to the present invention, wherein the first stripping component comprises or consists of one or more alkanolamines featuring a tertiary amino group containing three hydroxy groups (triols), preferably comprises or consists of trimethanolamine, triethanolamine (TEA), tris(3-hydroxypropyl)amine and / or triisopranolamine, more preferably comprises or consists of triethanolamine (TEA).

[0140] It has been found out that the first stripping component as defined herein and as defined in the claims is very versatile and can be applied in a wide variety of different stripping compositions wherein in each case the presence of the first stripping component has been proven to be beneficial in terms of photoresist removal performance without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0141] Preferred is a photoresist stripping composition according to the present invention, wherein N-Formylmorpholine (NFM) is present in a concentration of 20 wt.% to 80 wt.%, preferably in a concentration of 25 wt.% to 75 wt.%, in the photoresist stripping composition.BASF SE

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[0147] Said preferred concentration ranges of the solvent N-Formylmorpholine (NFM) are particularly beneficial in terms of photoresist removal performance without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0148] Also preferred is a photoresist stripping composition according to the present invention, wherein the first stripping component is present in a concentration of 4 wt.% to 45 wt.%, preferably in a concentration of 5 wt.% to 40 wt.%, in the photoresist stripping composition.

[0149] Said preferred concentration ranges of the first stripping component consisting of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group are particularly beneficial in terms of photoresist removal performance without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0150] Also preferred is a photoresist stripping composition according to the present invention, wherein the second stripping component is present in a concentration of 7 wt.% to 55 wt.%, preferably in a concentration of 10 wt.% to 50 wt.%, in the photoresist stripping composition.

[0151] Said preferred concentration ranges of the second stripping component consisting of one or more compounds selected from the group consisting of lactones, lactams and amides or consisting of one or more compounds selected from the group consisting of heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups, and ureas, are particularly beneficial in terms of photoresist removal performance without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0152] More preferred is a photoresist stripping composition according to the present invention, wherein

[0153] - N-Formylmorpholine (NFM) is present in a concentration of 20 wt.% to 80 wt.%, preferably in a concentration of 25 wt.% to 75 wt.%, in the photoresist stripping composition,

[0154] and

[0155] - the first stripping component is present in a concentration of 4 wt.% to 45 wt.%, preferably in a concentration of 5 wt.% to 40 wt.%, in the photoresist stripping composition,

[0156] andBASF SE

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[0162] - the second stripping component is present in a concentration of 7 wt.% to 55 wt.%, preferably in a concentration of 10 wt.% to 50 wt.%, in the photoresist stripping composition.

[0163] The fulfilment of all preferred concentration ranges of N-Formylmorpholine (NFM), the first stripping component and the second stripping component is even more particularly beneficial in terms of photoresist removal performance without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0164] Preferred is a photoresist stripping composition according to the present invention, wherein the mass ratio of N-Formylmorpholine (NFM) to the first stripping component is in a range of from 10:1 to 1:4, preferably in a range of from 9:1 to 1:3, more preferably in a range of from 8:1 to 1:2.

[0165] Said preferred mass ratios of N-Formylmorpholine (NFM) to the first stripping component are particularly beneficial in terms of photoresist removal performance without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0166] Also preferred is a photoresist stripping composition according to the present invention, wherein the mass ratio of N-Formylmorpholine (NFM) to the second stripping component is in a range of from 7:1 to 1:5, preferably in a range of from 6:1 to 1:4, more preferably in a range of from 5:1 to 1:3.

[0167] Said preferred mass ratios of N-Formylmorpholine (NFM) to the second stripping component are particularly beneficial in terms of photoresist removal performance without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0168] Also preferred is a photoresist stripping composition according to the present invention, wherein the mass ratio of the first stripping component to the second stripping component is in a range of from 4:1 to 1:7, preferably in a range of from 3:1 to 1:6, more preferably in a range of from 2:1 to 1:5.

[0169] Said preferred mass ratios of the first stripping component to the second stripping component are particularly beneficial in terms of photoresist removal performance without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0170] Also preferred is a photoresist stripping composition according to the present invention, wherein the mass ratio of N-Formylmorpholine (NFM) to the first and second stripping component is in a rangeBASF SE

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[0176] of from 5:1 to 1:5, preferably in a range of from 4:1 to 1:4, more preferably in a range of from 3:1 to 1:3.

[0177] Said preferred mass ratios of N-Formylmorpholine (NFM) to the first and second stripping component are particularly beneficial in terms of photoresist removal performance without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0178] More preferred is a photoresist stripping composition according to the present invention, wherein

[0179] - the mass ratio of N-Formylmorpholine (NFM) to the first stripping component is in a range of from 10:1 to 1:4, preferably in a range of from 9:1 to 1:3, more preferably in a range of from 8:1 to 1:2,

[0180] and

[0181] - the mass ratio of N-Formylmorpholine (NFM) to the second stripping component is in a range of from 7:1 to 1:5, preferably in a range of from 6:1 to 1:4, more preferably in a range of from 5:1 to 1:3,

[0182] and

[0183] - the mass ratio of the first stripping component to the second stripping component is in a range of from 4:1 to 1:7, preferably in a range of from 3:1 to 1:6, more preferably in a range of from 2:1 to 1:5,

[0184] and

[0185] - the photoresist stripping composition according to any of the preceding claims, wherein the mass ratio of N-Formylmorpholine (NFM) to the first and second stripping component is in a range of from 5:1 to 1:5, preferably in a range of from 4:1 to 1:4, more preferably in a range of from 3:1 to 1:3.

[0186] The fulfilment of all preferred mass ratios of the components within the photoresist stripping composition is even more particularly beneficial in terms of photoresist removal performance without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0187] The inventors of the present invention have prepared and investigated several different photoresist stripping compositions and have tested several different compounds. It has been found that certain compounds are particularly suitable as they lead to a photoresist stripping compositions with excellent performance in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.BASF SE

[0188]

[0189] 240899

[0190]

[0191] 240899 WO01

[0192]

[0193] Accordingly, a photoresist stripping composition according to the present invention is preferred, wherein the first stripping component comprises or consists of one or more alkanolamines featuring a dimethylamino group, preferably comprises or consists of 2-[2-(Dimethylamino)ethoxy]ethanol and / or 2-Dimethylamino-2-methylpropan-1-ol, more preferably the first stripping component is 2-[2-(Dimethylamino)ethoxy]ethanol.

[0194] Likewise, a photoresist stripping composition according to the present invention is preferred, wherein the first stripping component comprises or consists of one or more alkanolamines featuring a tertiary amino group containing three hydroxy groups (triols), preferably comprises or consists of trimethanolamine, triethanolamine (TEA), tris(3-hydroxypropyl)amine and / or triisopranolamine, more preferably comprises or consists of triethanolamine (TEA). In particular the presence of 2-[2-(Dimethyl-amino)ethoxy]ethanol and / or 2-Dimethylamino-2-methylpropan-1-ol and / or triethanolamine (TEA) in a concentration of 3 wt.% to 50 wt.% in the photoresist stripping composition or in a preferred concentration as described herein with respect to the first stripping component, leads to excellent results in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0195] Moreover, 2-[2-(Dimethylamino)ethoxy]ethanol, 2-Dimethylamino-2-methylpropan-1-ol and triethanolamine (TEA) are advantageously not classified as Substances of Very High Concern (SVHC) according to the REACH classification and are also not classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) or hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. These compounds thus contribute to the non-toxic, easy to handle and eco-friendly properties of the photoresist stripping composition according to the present invention.

[0196] The photoresist stripping composition according to the present invention has proven to be very versatile with regard to the second stripping component. The solvent N-Formylmorpholine (NFM) and the first stripping component consisting of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group as defined herein can be combined with a variety of different chemicals. It has been found that compounds selected from the group consisting of lactones, lactams, amides and mixtures thereof or compounds selected from the group consisting of heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups, ureas and mixtures thereof are all suitable to serve as theBASF SE

[0197]

[0198] 240899

[0199]

[0200] 240899 WO01

[0201]

[0202] second stripping component. All of these compounds showed excellent results in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself. The general inventive concept is thus not limited to one of the specific chemical compounds as included within the list of compounds with respect to the second stripping component but can be applied in a broader context. Correspondingly, the second stripping component as present within the photoresist stripping composition according to the present invention can be designed in multiple ways / embodiments and is particularly designed as defined in the claims and / or according to the preferred embodiments as stated herein.

[0203] A first group of substances which have been identified as particularly suitable second stripping component is made up of the following compounds: lactones, lactams, amides and mixtures thereof (aspect 1).A first preferred embodiment of aspect 1 of the present invention pertains to a photoresist stripping composition, wherein the second stripping component comprises or consists of one or more lactones, preferably comprises or consists of one or more substituted or unsubstituted valerolactones and / or one or more substituted or unsubstituted butyrolactones, more preferably comprises or consists of gamma-valerolactone (GVL), gamma-butyrolactone (GBL), 5-tetrahydrofuran-2-yl-tetrahy-drofuran-2-one (y-THF-Butyrolactone) and / or p-Methyl-5-valerolactone (BMVL).

[0204] According to this first preferred embodiment of aspect 1 of the present invention it is preferred that the second stripping component only consists of one or more lactones, preferably only consists of one or more of the preferred lactones as stated herein.

[0205] A photoresist stripping composition whose second stripping component comprises or consists of above-mentioned lactone compounds leads to excellent results in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0206] Moreover, lactones, in particular the preferred lactones as stated above are advantageously not classified as Substances of Very High Concern (SVHC) according to the REACH classification and are also not classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) or hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. These compounds thus contribute to the non-toxic, easy to handle and eco-friendly properties of the photoresist stripping composition according to the present invention.BASF SE

[0207]

[0208] 240899

[0209]

[0210] 240899 WO01

[0211]

[0212] A second preferred embodiment of aspect 1 of the present invention pertains to a photoresist stripping composition, wherein the second stripping component comprises or consists of one or more lactams, preferably comprises or consists of one or more substituted or unsubstituted valerolactams and / or one or more substituted or unsubstituted butyrolactams, more preferably comprises or consists of hydroxyethylpyrrolidone (HEP).

[0213] According to this second preferred embodiment of aspect 1 of the present invention it is preferred that the second stripping component only consists of one or more lactams, preferably only consists of one or more of the preferred lactams as stated herein.

[0214] A photoresist stripping composition whose second stripping component comprises or consists of above-mentioned lactam compounds leads to excellent results in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0215] Moreover, lactams, in particular the preferred lactams as stated above are advantageously not classified as Substances of Very High Concern (SVHC) according to the REACH classification and are also not classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) or hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. These compounds thus contribute to the non-toxic, easy to handle and eco-friendly properties of the photoresist stripping composition according to the present invention.

[0216] A third preferred embodiment of aspect 1 of the present invention pertains to a photoresist stripping composition, wherein the second stripping component comprises or consists of one or more amides, preferably comprises or consists of one or more substituted or unsubstituted N,N-dialkyl amides, more preferably comprises or consists of one or more substituted or unsubstituted N,N-dimethyl amides, most preferably comprises or consists of N,N-dimethylpropionamide and / or 2-Hydroxy-N,N-dimethylpropanamide.

[0217] According to this third preferred embodiment of aspect 1 of the present invention it is preferred that the second stripping component only consists of one or more amides, preferably only consists of one or more of the preferred amides as stated herein.BASF SE

[0218]

[0219] 240899

[0220]

[0221] 240899 WO01

[0222]

[0223] A photoresist stripping composition whose second stripping component comprises or consists of above-mentioned amide compounds leads to excellent results in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0224] Moreover, the preferred amides as stated herein are advantageously not classified as Substances of Very High Concern (SVHC) according to the REACH classification and are also not classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) or hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. These compounds thus contribute to the non-toxic, easy to handle and eco-friendly properties of the photoresist stripping composition according to the present invention.

[0225] A fourth preferred embodiment of aspect 1 of the present invention pertains to a photoresist stripping composition, wherein the second stripping component consists of a mixture of

[0226] - lactones and lactams, preferably consist of a mixture of preferred lactones and preferred lactams as stated herein,

[0227] or

[0228] - lactones and amides, preferably consist of a mixture of preferred lactones and preferred amides as stated herein,

[0229] or

[0230] - lactams and amides, preferably consist of a mixture of preferred lactams and preferred amides as stated herein,

[0231] or

[0232] - lactones, lactams and amides, preferably consist of a mixture of preferred lactones, preferred lactams and preferred amides as stated herein.BASF SE

[0233]

[0234] 240899

[0235]

[0236] 240899 WO01

[0237]

[0238] It has been found that a combination of lactones, lactams and / or amides in the photoresist stripping composition is feasible and in some cases even advantageous in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0239] A second group of substances which have been identified as particularly suitable second stripping component is made up of the following compounds: heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups, ureas and mixtures thereof (aspect 2).

[0240] A first preferred embodiment of aspect 2 of the present invention pertains to a photoresist stripping composition, wherein the second stripping component comprises or consists of one or more heterocyclic cycloalkanones, preferably comprises or consists of one or more oxygen-heterocyclic cycloalkanones, more preferably comprises or consists of one or more substituted or unsubstituted, monocyclic or bicyclic oxygen-heterocyclic cycloalkanones, even more preferably comprises or consists of one or more substituted or unsubstituted, monocyclic or bicyclic, five- to eight-membered oxygen-heterocyclic cycloalkanones most preferably comprises or consists of dihydrolevoglucosen-one (also referred to as Gyrene).

[0241] According to this first preferred embodiment of aspect 2 of the present invention it is preferred that the second stripping component only consists of one or more heterocyclic cycloalkanones, preferably only consists of one or more of the preferred heterocyclic cycloalkanones as stated herein.

[0242] Heterocyclic cycloalkanones comprise at least one heterocycle, the heterocycle featuring at least one ketone group (Rketone-C(=O)-R’ketone)> preferably featuring only one ketone group.

[0243] A photoresist stripping composition whose second stripping component comprises or consists of above-mentioned heterocyclic cycloalkanone compounds leads to excellent results in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0244] Moreover, heterocyclic cycloalkanones, in particular the preferred heterocyclic cycloalkanones as stated above are advantageously not classified as Substances of Very High Concern (SVHC) according to the REACH classification and are also not classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) or hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and LabellingBASF SE

[0245]

[0246] 240899

[0247]

[0248] 240899 WO01

[0249]

[0250] of Chemicals (GHS) in the year 2024. These compounds thus contribute to the non-toxic, easy to handle and eco-friendly properties of the photoresist stripping composition according to the present invention.

[0251] It has been found that oxygen-heterocyclic cycloalkanones, i.e., cycloalkanones featuring at least one oxygen atom in the heterocycle, are particularly suitable. In particular monocyclic or bicyclic oxygen-heterocyclic cycloalkanones such as dihydrolevoglucosenone, which is a bicyclic, sevenmembered heterocyclic cycloalkanone, showed a very good performance in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0252] A second preferred embodiment of aspect 2 of the present invention pertains to a photoresist stripping composition, wherein the second stripping component comprises or consists of one or more carbonate esters, preferably comprises or consists of one or more substituted or unsubstituted cyclic carbonate esters, more preferably comprises or consists of one or more substituted or unsubstituted five-membered cyclic carbonate esters, even more preferably comprises or consists of propylene carbonate.

[0253] Carbonate esters comprise at least one carbonate ester group (Rcarbonate ester_O-C(=O)-O-R'carbonateester), preferably comprise only one carbonate ester group.

[0254] According to this second preferred embodiment of aspect 2 of the present invention it is preferred that the second stripping component only consists of one or more carbonate esters, preferably only consists of one or more of the preferred carbonate esters as stated herein.

[0255] A photoresist stripping composition whose second stripping component comprises or consists of above-mentioned carbonate ester compounds leads to excellent results in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0256] Moreover, carbonate esters, in particular the preferred carbonate esters as stated above are advantageously not classified as Substances of Very High Concern (SVHC) according to the REACH classification and are also not classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) or hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. These compounds thus contribute to the non-toxic, easy to handle and eco-friendly properties of the photoresist stripping composition according to the present invention.BASF SE

[0257]

[0258] 240899

[0259]

[0260] 240899 WO01

[0261]

[0262] It has been found that substituted or unsubstituted cyclic carbonate esters, i.e., compounds wherein the carbonate ester group is part of a cyclic system, are particularly suitable. In particular fivemembered cyclic carbonate esters such as propylene carbonate showed a very good performance in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0263] A third preferred embodiment of aspect 2 of the present invention pertains to a photoresist stripping composition, wherein the second stripping component comprises or consists of one or more carbamates, preferably comprises or consists of one or more substituted or unsubstituted cyclic carbamates, more preferably comprises or consists of one or more substituted or unsubstituted fivemembered cyclic carbamates, even more preferably comprises or consists of 3-methyloxazolidin-2-one.

[0264] Carbamates comprise at least one carbamate group (RcarbamateR'carbamateN-C(=O)-O-R"carbamate) formally derived from carbamic acid, preferably comprise only one carbamate group.

[0265] According to this third preferred embodiment of aspect 2 of the present invention it is preferred that the second stripping component only consists of one or more carbamates, preferably only consists of one or more of the preferred carbamates as stated herein.

[0266] A photoresist stripping composition whose second stripping component comprises or consists of above-mentioned carbamate compounds leads to excellent results in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0267] Moreover, the preferred carbamates as stated herein are advantageously not classified as Substances of Very High Concern (SVHC) according to the REACH classification and are also not classified as acute toxic, category 1 to 3 (GHS06) or health hazardous, category 1, 1A, 1B (GHS08) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. These compounds thus contribute to the non-toxic, easy to handle and eco-friendly properties of the photoresist stripping composition according to the present invention.

[0268] It has been found that substituted or unsubstituted cyclic carbamates, i.e., compounds wherein the carbamate group is part of a cyclic system, are particularly suitable. In particular five-membered cyclic carbamates such as 3-methyloxazolidin-2-one showed a very good performance in terms ofBASF SE

[0269]

[0270] 240899

[0271]

[0272] 240899 WO01

[0273]

[0274] photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0275] A fourth preferred embodiment of aspect 2 of the present invention pertains to a photoresist stripping composition, wherein the second stripping component comprises or consists of one or more acyclic carboxylic esters, preferably comprises or consists of one or more acyclic alkyl esters and / or acyclic ketoesters, more preferably comprises or consists of one or more acyclic C1 to C4 alkyl ketoesters, even more preferably comprises or consists of methyl levulinate.

[0276] Acyclic carboxylic esters do not contain any (cyclic) lactone group and comprise at least one carboxylic ester group (Rcarboxyiicester_C(=O)-O-R'carboXyiiC ester) formally derived from a carboxylic acid in which the hydrogen atom of at least one acidic hydroxyl group (-OH) of that acid is replaced by an organyl group (R1carboxyiic ester), wherein replacement usually occurs via a substitution reaction between a carboxylic acid (Rcarboxyiic ester-C(=O)-OH) and an alcohol (R1carboxyiicester-OH), preferably acyclic carboxylic esters comprise only one carboxylic ester group.

[0277] Ketoesters are a subclass of carboxylic esters, which additionally comprise at least one ketone group (RketoneR'ketoneC=O), preferably comprise only one ketone group, wherein said ketone group is usually present within the organyl group derived from the carboxylic acid (Rcarboxyiic ester).

[0278] Alkyl esters are a subclass of carboxylic esters, wherein at least one of the two organyl groups (Rcarboxylic ester and Rcarboxylic ester ) is an alkyl group, preferably the organyl group R'carbOxyiic ester (formally) deriving from the alcohol is an alkyl group. The number of carbon atoms of the alkyl group is expressed via the common abbreviations C1, C2, C3, C4, etc.

[0279] Alkyl ketoesters are carboxylic esters, I) which additionally comprise at least one ketone group (RketOneR'ketoneC=O) wherein said ketone group is usually present within the organyl group derived from the carboxylic acid (RcarbOxyiic ester) and II) wherein one of the organyl groups (RcarbOxyiic ester or R'cerboxylic ester) is an alkyl group, usually the organyl group R'carbOxyiic ester deriving from the alcohol is an alkyl group.

[0280] According to this forth preferred embodiment of aspect 2 of the present invention it is preferred that the second stripping component only consists of one or more acyclic carboxylic esters, preferably only consists of one or more of the preferred acyclic carboxylic esters as stated herein.BASF SE

[0281]

[0282] 240899

[0283]

[0284] 240899 WO01

[0285]

[0286] A photoresist stripping composition whose second stripping component comprises or consists of above-mentioned acyclic carboxylic ester compounds leads to excellent results in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0287] Moreover, the preferred acyclic carboxylic esters as stated herein are advantageously not classified as Substances of Very High Concern (SVHC) according to the REACH classification and are also not classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1 A, 1 B (GHS08) or hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. These compounds thus contribute to the non-toxic, easy to handle and eco-friendly properties of the photoresist stripping composition according to the present invention.

[0288] It has been found that acyclic alkyl esters and / or acyclic ketoesters are particularly suitable. In particular acyclic C1 to C4 alkyl ketoesters such as methyl levulinate showed a very good performance in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0289] A fifth preferred embodiment of aspect 2 of the present invention pertains to a photoresist stripping composition, wherein the second stripping component comprises or consists of one or more ethers not containing any tertiary amino groups, preferably comprises or consists of one or more glycol ethers, more preferably comprises or consists of ethylene and / or propylene glycol ethers with a maximum number of 5 ethylene oxide (EG) units and / or propylene oxide (PO) units, even more preferably comprises or consists of di (propylene glycol) methyl ether and / or diethylene glycol diethyl ether.

[0290] Ethers not containing any tertiary amino groups comprise at least one ether group (Rether-O-R'ether), preferably comprise one, two or three ether groups, more preferably comprise two or three ether groups. Compounds like 2-[2-(Dimethylamino)ethoxy]ethanol which are ethers and which at the same time are also classified as alkanolamines featuring a tertiary amino group are not counted under "ethers not containing any tertiary amino groups” but are counted under the first stripping component consisting of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group.BASF SE

[0291]

[0292] 240899

[0293]

[0294] 240899 WO01

[0295]

[0296] Glycol ethers are a class of chemical compounds consisting of alkyl ethers that are based on glycols such as ethylene glycol and / or propylene glycol with a certain number of ethylene oxide (EO) units and / or propylene oxide (PO) units.

[0297] According to this fifth preferred embodiment of aspect 2 of the present invention it is preferred that the second stripping component only consists of one or more ethers not containing any tertiary amino groups, preferably only consists of one or more of the preferred ethers not containing any tertiary amino groups as stated herein.

[0298] A photoresist stripping composition whose second stripping component comprises or consists of above-mentioned ethers not containing any tertiary amino groups leads to excellent results in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0299] Moreover, the preferred ethers not containing any tertiary amino groups as stated herein are advantageously not classified as Substances of Very High Concern (SVHC) according to the REACH classification and are also not classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) or hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. These compounds thus contribute to the non-toxic, easy to handle and eco-friendly properties of the photoresist stripping composition according to the present invention.

[0300] It has been found that glycol ethers are particularly suitable. In particular ethylene and / or propylene glycol ethers with a maximum number of 5 ethylene oxide (EO) units and / or propylene oxide (PO) units such as di (propylene glycol) methyl ether or diethylene glycol diethyl ether showed a very good performance in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0301] A sixth preferred embodiment of aspect 2 of the present invention pertains to a photoresist stripping composition, wherein the second stripping component comprises or consists of one or more ureas, preferably comprises or consists of one or more substituted or unsubstituted cyclic ureas, more preferably comprises or consists of one or more substituted or unsubstituted five-membered cyclic ureas, even more preferably comprises or consists of 1 ,3-dimethyl-2-imidazolidinone.BASF SE

[0302]

[0303] 240899

[0304]

[0305] 240899 WO01

[0306]

[0307] Ureas are a class of organic compounds comprising at least one urea group (RureaR'ur-eaN)-C(=O)-(NR”'ureaR'”'urea), preferably ureas comprise only one urea group.

[0308] According to this sixth preferred embodiment of aspect 2 of the present invention it is preferred that the second stripping component only consists of one or more ureas, preferably only consists of one or more of the preferred ureas as stated herein.

[0309] A photoresist stripping composition whose second stripping component comprises or consists of above-mentioned ureas leads to excellent results in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0310] Moreover, the preferred ureas as stated herein are advantageously not classified as Substances of Very High Concern (SVHC) according to the REACH classification and are also not classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) or hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. These compounds thus contribute to the non-toxic, easy to handle and eco-friendly properties of the photoresist stripping composition according to the present invention.

[0311] It has been found that substituted or unsubstituted cyclic ureas, i.e., compounds wherein the urea group is part of a cyclic system, are particularly suitable. In particular substituted or unsubstituted five-membered cyclic ureas such as 1 ,3-dimethyl-2-imidazolidinone showed a very good performance in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0312] A seventh preferred embodiment of aspect 2 of the present invention pertains to a photoresist stripping composition, wherein the second stripping component consists of a mixture of at least two of the following compounds:

[0313] - heterocyclic cycloalkanones,

[0314] - carbonate esters,

[0315] - carbamates,BASF SE

[0316]

[0317] 240899

[0318]

[0319] 240899 WO01

[0320]

[0321] - acyclic carboxylic esters,

[0322] - ethers not containing any tertiary amino groups, and

[0323] - ureas.

[0324] Preferably the second stripping component consists of a mixture of two, three or four, preferably two, compounds selected from the group consisting of heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups and ureas, more preferably selected from those heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups and ureas which are designated as preferred herein.

[0325] Exemplary (and not limiting) preferred photoresist stripping compositions according to the present invention, wherein the second stripping component is a mixture of different compounds, are characterized by a second stripping component consisting of:

[0326] - one or more heterocyclic cycloalkanones and one or more carbonate esters, preferably consisting of a mixture of one or more preferred heterocyclic cycloalkanones and one or more preferred carbonate esters as stated herein, or

[0327] - one or more carbamates and one or more acyclic carboxylic esters, preferably consisting of a mixture of one or more preferred carbamates and one or more preferred acyclic carboxylic esters as stated herein, or

[0328] - one or more heterocyclic cycloalkanones and one or more ethers not containing any tertiary amino groups and one or more ureas, preferably consisting of a mixture of one or more preferred heterocyclic cycloalkanones and one or more preferred ethers not containing any tertiary amino groups and one or more preferred ureas as stated herein.

[0329] It has been found that a combination of heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups and / or ureas in the photoresist stripping composition is feasible and in some cases even advantageous in terms of photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.BASF SE

[0330]

[0331] 240899

[0332]

[0333] 240899 WO01

[0334]

[0335] Preferred is a photoresist stripping composition according to the present invention, in particular a photoresist stripping composition wherein the first stripping component is triethanolamine, wherein the photoresist stripping composition when present in a 10 wt.-% solution in deionized water has a pH-value in a range of from 7.5 to 12.0, preferably in a range of from 8.0 to 11.5, more preferably in a range of from 8.5 to 11.0, even more preferably in a range of from 9.0 to 10.5.

[0336] Also preferred is a photoresist stripping composition according to aspect 1 of the present invention (with a second stripping component consisting of one or more compounds selected from the group consisting of lactones, lactams and amides), wherein the photoresist stripping composition when present in a 10 wt.-% solution in deionized water has a pH-value in a range of from 9.0 to 12.0, preferably in a range of from 9.5 to 11.5, more preferably in a range of from 10.0 to 11.3.

[0337] Likewise preferred is a photoresist stripping composition according to aspect 2 of the present invention (with a second stripping component consisting of one or more compounds selected from the group consisting of heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups, and ureas), wherein the photoresist stripping composition when present in a 10 wt.-% solution in deionized water has a pH-value in a range of from 9.0 to 12.0, preferably in a range of from 9.5 to 11.8, more preferably in a range of from 10.0 to 11.6. The pH-value of the photoresist stripping composition when present in a 10 wt.-% solution in deionized water can be determined by a skilled person via establishes measuring methods known in the art. Said preferred pH-values in a moderate to medium alkaline range allows for an effective photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0338] Also preferred is a photoresist stripping composition according to the present invention, wherein the photoresist stripping composition has a flash point of at least 45 °C, preferably of at least 50 °C, more preferably of at least 60 °C.

[0339] The flash point of the photoresist stripping composition can be determined by a skilled person via established measuring methods known in the art. Said preferred flash points of the photoresist stripping composition allow for a safe handling of the photoresist stripping composition and also allow for an application at elevated temperatures above room temperature which accelerates the stripping process. The photoresist stripping composition can generally be safely subjected to temperatures ofBASF SE

[0340]

[0341] 240899

[0342]

[0343] 240899 WO01

[0344]

[0345] at most 5 °C below the flash point of the photoresist stripping composition, preferably of at most 10 °C below the flash point of photoresist stripping composition.

[0346] Also preferred is a photoresist stripping composition according to the present invention, wherein the individual components of the photoresist stripping composition have a flash point of at least 45 °C, preferably of at least 50 °C, more preferably of at least 60 °C.

[0347] The flash points of the individual components of the photoresist stripping composition can be pertained from data sheets of the respective compounds or can be determined by a skilled person via establishes measuring methods known in the art. Said preferred flash points of the individual components of the photoresist stripping composition allow for a safe handling of the photoresist stripping composition and also allow for an application at elevated temperatures above room temperature which accelerates the stripping process. The photoresist stripping composition can generally be safely subjected to temperatures of at most 5 °C below the flash point of the individual components of the photoresist stripping composition, preferably of at most 10 °C below the flash point of the individual components of the photoresist stripping composition.

[0348] Preferred is a photoresist stripping composition according to the present invention, wherein the photoresist stripping composition has an etching rate of metal substrates of at most 20 A / min, preferably of at most 15 A / min, more preferably of at most 10 A / min, wherein the etching rate is determined via immersion tests of metallic substrates at 60 °C and investigated via wavelength dispersive X-ray fluorescence (WD-XRF) analysis or 4-point probing measurements of the metal substrate.

[0349] The etching rate (Re) is calculated using the following formula I:

[0350] D_ d1— d2

[0351] e~ t

[0352] formula (I)

[0353] wherein

[0354] Reis the etching rate in A / min,

[0355] d-t is the thickness of the substrate before etching in A,BASF SE

[0356]

[0357] 240899

[0358]

[0359] 240899 WO01

[0360]

[0361] d2is the thickness of the substrate after etching in A, and

[0362] t is the etching time in minutes (min).

[0363] Etching rates are determined via common test procedures involving immersion of the investigated substrate with a predefined thickness di into the photoresist stripping composition at a predefined temperature for a predefined time and by determining the thickness d2of the substrate after etching in A.

[0364] The relatively low etching rate of photoresist stripping compositions according to the present inven¬ tion on metal substrates is a particular advantage as low etching rates of under 20 A / min, in most cases of under 10 A / min, correspond to a system that successfully removes photoresist material without substantially etching, altering or otherwise negatively affecting the substrate.

[0365] The present invention also pertains to the use of 2-[2-(Dimethylamino)ethoxy]ethanol and / or 2-Di-methylamino-2-methylpropan-1-ol, preferably use of 2-[2-(Dimethylamino)ethoxy]ethanol, as compound in a photoresist stripping composition comprising N-Formylmorpholine (NFM) for removing photoresist material from a substrate.

[0366] Preferably 2-[2-(Dimethylamino)ethoxy]ethanol and / or 2-Dimethylamino-2-methylpropan-1-ol are used in a photoresist stripping composition according to the present invention, for removing photoresist material from a substrate.

[0367] The inventors have for the first time found out that 2-[2-(Dimethylamino)ethoxy]ethanol and / or 2-Dimethylamino-2-methylpropan-1-ol, in particular 2-[2-(Dimethylamino)ethoxy]ethanol, are very suitable stripping components / compounds which can be used in a photoresist stripping composition and which positively contribute to the stripping process. In particular the use of that 2-[2-(Dimethyl-amino)ethoxy]ethanol and / or 2-Dimethylamino-2-methylpropan-1-ol in photoresist stripping compositions based on N-Formylmorpholine (NFM) as solvent substantially increases the removal capacity of photoresist material. At the same time 2-[2-(Dimethylamino)ethoxy]ethanol and 2-Dimethylamino-2-methylpropan-1-ol are also compatible with a wide variety of different substrates and have found out to not substantially etch, alter or otherwise negatively affect the substrate, in particular metal substrates. Furthermore the use of 2-[2-(Dimethylamino)ethoxy]ethanol and / or 2-Dimethylamino-2-methylpropan-1-ol in a photoresist stripping composition is beneficial as these compounds are not classified as Substances of Very High Concern (SVHC) according to the REACH classification andBASF SE

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[0373] are also not classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) or hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024.

[0374] The present invention also pertains to the use of a photoresist stripping composition according to the invention, preferably use of a photoresist stripping composition designated as preferred herein, for removing photoresist material from a substrate.

[0375] Preferably the photoresist stripping composition according to the invention is used for removing positive photoresist material from a substrate, more preferably for removing photoresist material comprising or consisting of thermoplastic (co-)polymer.

[0376] Even more preferably the photoresist stripping composition according to the invention is used for removing positive photoresist material in the form of thermoplastic (co-)polymers used in lithography for the production of integrated circuits. Examples of suitable positive photoresist material are inter alia described in Xu et al., Photoresist chemistry in the semiconductor field, Polymer Journal (2018) 50, 45-55, in particular poly(p-chloromethylstyrene) (PCMS) or (co-)polymers composed of a-gamma butyrolactone methacrylate (GBLMA), methyl adamantyl methacrylate (MAMA) and / or hydroxyl adamantyl methacrylate (HAMA) are suitable positive photoresist materials. Other suitable positive photoresist materials are electron beam lithography resists such as poly methyl methacrylate (PMMA) or a a-chloromethacrylate / o-methylstyrene co-polymer which is inter alia commercially available as ZEP520 from Zeon Chemicals (Japan).

[0377] Also preferably the photoresist stripping composition according to the invention is used for removing photoresist material from a substrate with a metal surface, in particular from a metal surface consisting of copper, aluminium, tungsten, cobalt, nickel tin, silver and / or molybdenum.

[0378] The present invention also pertains to a process of removing photoresist material from a substrate, the process at least comprising the following steps:

[0379] I) providing or preparing a substrate comprising photoresist material on the substrate surface,

[0380] ii) providing or preparing a photoresist stripping composition according to the present invention,BASF SE

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[0386] iii) contacting the substrate comprising photoresist material on the substrate surface with the provided or prepared photoresist stripping composition, so that the photoresist material is at least partly, preferably completely, removed from the substrate surface.

[0387] Preferred is a process of removing photoresist material from a substrate, wherein the provided or prepared substrate comprising photoresist material on the substrate surface comprises a metal surface, preferably a metal surface comprising or consisting of copper, aluminium, tungsten, cobalt, nickel tin, silver and / or molybdenum or any combination thereof, more preferably the metal surface is a copper surface or an aluminium surface or comprises tin and / or silver coated copper structures.

[0388] Also preferred is a process of removing photoresist material from a substrate, wherein the provided or prepared substrate comprising photoresist material on the substrate surface comprises a positive photoresist material, preferably the photoresist material is a thermoplastic (co )polymer.

[0389] Preferred is a process of removing photoresist material from a substrate, wherein the step of iii) contacting the substrate comprising photoresist material on the substrate surface with the provided or prepared photoresist stripping composition is carried out by immersion of the substrate comprising photoresist material into the provided or prepared photoresist stripping composition.

[0390] The step of iii) contacting the substrate comprising photoresist material on the substrate surface with the provided or prepared photoresist stripping composition is preferably carried out in one step or in two steps.

[0391] In a first preferred embodiment of the present invention the substrate comprising photoresist material on the substrate surface is contacted with the provided or prepared photoresist stripping composition in a one-step procedure by immersion in a batch process. Said batch process is preferably conducted in a tank containing the provided or prepared photoresist stripping composition according to the present invention. More preferably the batch process involves immersion of several substrates comprising photoresist material on the substrate surface into the photoresist stripping composition, in particular a number of 2 to 50 substrates, preferably substrates in the form of wafers.

[0392] In a second preferred embodiment of the present invention the substrate comprising photoresist material on the substrate surface is contacted with the provided or prepared photoresist stripping composition in a one-step procedure by spraying in an individual spraying process. Said individual spraying process is preferably conducted via spraying the provided or prepared photoresist stripping com-BASF SE

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[0398] position according to the present invention onto the substrate surface, preferably on a single substrate in the form of a wafer.

[0399] In a third preferred embodiment of the present invention the substrate comprising photoresist material on the substrate surface is contacted with the provided or prepared photoresist stripping composition in a two-step procedure including the batch process as described above, which is usually conducted as a first step, and the individual spraying process as described above, which is usually conducted as a second step after the batch process.

[0400] Particularly preferred is a process of removing photoresist material from a substrate, wherein the immersion of the substrate comprising photoresist material into the provided or prepared photoresist stripping composition is conducted for a time period in a range of from 1 to 20 minutes, preferably for a time period in a range of from 2 to 16 minutes, more preferably for a time period in a range of from 3 to 12 minutes.

[0401] Also particularly preferred is a process of removing photoresist material from a substrate, wherein the provided or prepared photoresist stripping composition is heated to a temperature in a range of from 25 °C to 90 °C, preferably heated to a temperature in a range of from 40 °C to 80 °C.

[0402] Also particularly preferred is a process of removing photoresist material from a substrate, wherein the provided or prepared photoresist stripping composition is heated to a temperature of at most 5 °C below the flash point of the photoresist stripping composition, preferably of at most 10 °C below the flash point of the photoresist stripping composition.

[0403] The present invention also pertains to a process for the production of an integrated circuit, comprising the process of removing photoresist material from a substrate as described herein.

[0404] The process of removing photoresist material from a substrate can be easily incorporated into the overall production process of electronic materials, in particular into the production process of integrated circuits.

[0405] EXAMPLES

[0406] The following examples according to the present invention are meant to further explain and illustrate the present invention without limiting its scope.

[0407] 1. Exemplary photoresist stripping compositions for removing photoresist material:BASF SE

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[0413] 1.1 Compounds used for photoresist stripping compositions according to the present invention

[0414] The following compounds have been used as preferred embodiments of components in the photoresist stripping composition. We note that any other materials fulfilling the definitions as set forth in the claims are also suitable.

[0415] N-Formylmorpholine (CAS No. 4394-85-8): flash point: 118 °C; not classified as having an acute toxicity of category 1 to 3; not classified as serious health hazard of category 1 , 1 A, 1 B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern; commercially available from BASF.

[0416] Compounds falling under the definition of the first stripping component consisting of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group:

[0417] - 2-[2-(Dimethylamino)ethoxy]ethanol (CAS No. 1704-62-7): flash point 93 °C; not classified as having an acute toxicity of category 1 to 3; not classified as serious health hazard of category 1 , 1 A, 1 B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern; commercially available from BASF.

[0418] - 2-(Dimethylamino)-2-methylpropan-1-ol (CAS No. 7005-47-2): flash point 63 °C; not classified as having an acute toxicity of category 1 to 3; not classified as serious health hazard of category 1 , 1 A, 1B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern; commercially available from Advancion.

[0419] Triethanolamine (CAS No. 102-71-6): flash point 179 °C; not classified as having an acute toxicity of category 1 to 3; not classified as serious health hazard of category 1, 1A, 1B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern; commercially available from BASF.

[0420] Compounds falling under the definition of the second stripping component consisting of one or more compounds selected from the group consisting of lactones, lactams and amides (aspect 1):

[0421] Lactones:BASF SE

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[0427] - y-Valerolactone (CAS No. 108-29-2): flash point 81 °C; not classified as having an acute toxicity of category 1 to 3; not classified as serious health hazard of category 1, 1A, 1B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern; commercially available from BASF.

[0428] - y-Butyrolactone (CAS No. 96-48-0): flash point 98 °C; not classified as having an acute toxicity of category 1 to 3; not classified as serious health hazard of category 1, 1A, 1B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern; commercially available from Sigma-Aldrich.

[0429] Lactams:

[0430] - N-(2-Hydroxyethyl)-2-pyrrolidone (CAS No. 3445-11-2): flash point 100 °C; not classified as having an acute toxicity of category 1 to 3; not classified as serious health hazard of category 1 , 1 A, 1 B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern; commercially available from BASF.

[0431] Amides:

[0432] - 2-Hydroxy-N,N-dimethylpropanamide (CAS No. 35123-06-9): flash point 109.5 °C; not classified as having an acute toxicity of category 1 to 3; not classified as serious health hazard of category 1 , 1 A, 1B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern; commercially available from BASF.

[0433] -N,N-Dimethylpropionamide (CAS No. 758-96-3): flash point 62 °C; not classified as having an acute toxicity of category 1 to 3; not classified as serious health hazard of category 1 , 1 A, 1 B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern; commercially available from Sigma-Aldrich.

[0434] Compounds falling under the definition of the second stripping component consisting of one or more compounds selected from the group consisting of heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups, and ureas (aspect 2):

[0435] Heterocyclic cycloalkanones:BASF SE

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[0438]

[0439] Dihydrolevoglucosenone (CAS No. 53716-82-8): flash point 108 °C; not classified as having an acute toxicity of category 1 to 3; not classified as a serious health hazard of category 1 , 1 A, 1 B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern; commercially available as Gyrene.

[0440] Carbonate esters:

[0441] Propylene carbonate (CAS No. 108-32-7): flash point 132 °C; not classified as having an acute toxicity of category 1 to 3; not classified as a serious health hazard of category 1 , 1 A, 1 B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern.

[0442] Carbamates:

[0443] 3-Methyloxazolidin-2-one (CAS No. 19836-78-3): flash point 113 °C; not classified as having an acute toxicity of category 1 to 3; not classified as a serious health hazard according to category 1, 1A, 1B; not listed as substance of very high concern.

[0444] Acyclic carboxylic esters:

[0445] Methyl levulinate (CAS No. 624-45-3): flash point 72 °C; not classified as having an acute toxicity of category 1 to 3; not classified as a serious health hazard of category 1, 1A, 1B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern.

[0446] Ethers not containing any tertiary amino groups:

[0447] Propylene glycol phenyl ether (CAS No. 34590-94-8): flash point 75 °C; not classified as having an acute toxicity of category 1 to 3; not classified as a serious health hazard of category 1, 1A, 1B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern; commercially available from BASF.

[0448] Ethyldiglyme (CAS No. 112-36-7): flash point 71 °C; not classified as having an acute toxicity of category 1 to 3; not classified as a serious health hazard of category 1, 1A, 1B; not classified asBASF SE

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[0454] hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern.

[0455] Ureas:

[0456] 1 ,3-Dimethyl-2-imidazolidinone (CAS No. 80-73-9): flash point 120 °C; not classified as having an acute toxicity of category 1 to 3; not classified as a serious health hazard of category 1, 1A, 1B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern.

[0457] 1.2 Reference compounds not present in the photoresist stripping compositions according to the invention

[0458] - Tetramethylammonium hydroxide (TMAH; CAS No. 75-59-2): flash point N / A; classified as having an acute toxicity of category 2 (GHS06); classified as serious health hazard of category 1 (GHS08); classified as hazardous to the aquatic environment according to category 2 (GHS09); not listed as substance of very high concern.

[0459] - Dimethyl sulfoxide (CAS No. 67-68-5): flash point 89 °C; not classified as having an acute toxicity of category 1 to 3; not classified as serious health hazard of category 1, 1A, 1B; not classified as hazardous to the aquatic environment ac-cording to category 1 or 2; not listed as substance of very high concern.

[0460] Primary or secondary amines:

[0461] - 3,3'-l minobis(N, N-dimethylpropylamine) (CAS No. 6711-48-4): flash point 98 °C; classified as having an acute toxicity of category 3 (GHS06); not classified as serious health hazard of category 1, 1A, 1B; not classified as hazardous to the aquatic environment ac-cording to category 1 or 2; not listed as substance of very high concern.

[0462] - 2-(2-Aminoethoxy)ethanol (Diglycolamine, CAS No. 929-06-6): flash point 127 °C; not classified as having an acute toxicity of category 1 to 3; not classified as serious health hazard of category 1, 1A, 1B; not classified as hazardous to the aquatic environment according to category 1 or 2; not listed as substance of very high concern.BASF SE

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[0468] 1.3 Materials used as exemplary substrates comprising a photoresist material on the substrate surface

[0469] The following materials S1 to S4 have been used as exemplary embodiments of substrates comprising a photoresist material on the substrate surface:

[0470] S1 : substrate in the form of a 1.5 cm x 1.5 cm coupon comprising a PVD (physical vapour deposition) copper substrate surface featuring copper pillars with a thickness of around 25 pm obtained from electrochemical deposition (ECD) and a positive photoresist layer with a thickness of around 30 m (photoresist material based on 1-Methoxy-2-propanol acetate with a diazonaphthoquinone photoreagent; available as AZ 10XT from Merck); the substrate S1 is available from Fraunhofer Institute for Reliability and Microintegration IZM-ASSID. Substrate S1 is schematically depicted in Fig. 1.

[0471] S2: substrate in the form of a 1.5 cm x 1.5 cm coupon comprising a PVD (physical vapour deposition) copper substrate surface featuring copper pillars with a thickness of around 65 pm obtained from electrochemical deposition (ECD) and a positive photoresist layer with a thickness of around 75 pm (photoresist material from TOK); the substrate S2 is available from IMEC. Substrate S2 is schematically depicted in Fig. 2.

[0472] S3: 2.5 cm x 2.5 cm blanket coupon with an aluminium surface layer of 30 nm thickness deposited on a 100 nm SiO2base material; substrate S3 was purchased from IMEC.

[0473] S4: 2.5 cm x 2.5 cm blanket coupon with an ECD copper surface layer of 200 nm thickness deposited on a substrate consisting of the following layers: 1.) SiO2(100 nm thickness), 2.) Ta (25 nm thickness), 3.) PVD Cu (100 nm thickness); substrate S4 was purchased from Ramco.

[0474] 1.4 Preparation and chemical composition of exemplary photoresist stripping compositions

[0475] Exemplary photoresist stripping compositions were in each case prepared by adding the corresponding components with given concentrations and subsequent mixing for homogenization. The chemical composition of all tested photoresist stripping compositions is shown in tables 1 to 4 (see section 4).

[0476] 2. Analytical Methods

[0477] 2.1 Assessment of Photoresist RemovalBASF SE

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[0483] Following exposure to the stripping conditions (as described in detail below), the dry substrate materials were analysed with a laser scanning microscope (LSM) to assess the effectiveness of photoresist removal from the substrate surface. The laser scanning microscope (LSM) used was the 3D Laser Scanning Microscope -VK-X1000 from Keyence. Substrates were analysed under 5x magnification. The effectiveness of photoresist removal was rated on a stripping score from 1 to 3 based on comparison with reference images.

[0484] The stripping scores are as follows:

[0485] Stripping score 1 : The photoresist was successfully removed from the substrate without any residual material remaining. For reference, see Fig. 3.

[0486] Stripping score 2: The majority of photoresist was successfully removed, however, traces of photoresist material remained. For reference, see Fig. 4.

[0487] Stripping score 3: Photoresist removal was not successful, resulting in the residual presence of large amounts of photoresist material on the substrate surface. For reference, see Fig. 5.

[0488] In general, a stripping score of 1 is a good result, corresponding to an effective and complete photoresist removal from the substrate; a stripping score of 2 is a mediocre result, corresponding to a decent photoresist removal from the substrate; and a stripping score of 3 is a bad result wherein photoresist removal is unsuccessful.

[0489] 2.2 Determination of the Etching Rate

[0490] Following exposure to the etching conditions (as described in detail below), the dry substrate materials were characterized using either wavelength dispersive X-ray fluorescence (WD-XRF) analysis or 4-point probing whereby the film thickness d was measured before (d^ and after (d2) the etching experiments. For each investigated photoresist stripping composition double determination of etching rates were conducted, i.e., duplicate etching experiments and the respective evaluations were performed.

[0491] Wavelength dispersive X-ray fluorescence (WD-XRF) analysis were carried out with Rigaku AZX400 in a manner known per se (cf. e.g. N. Ekinci et al. in X-Ray Fluorescence in Biological Sciences:BASF SE

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[0495] Principles, Instrumentation and Applications, 1st ed., John Wiley & Sons Ltd., 2022 or H. Takahara in Rigaku Journal, 33(2), 2017).

[0496] 4-point probing measurements were carried out with Napson RT-3000 / RG-2000 using the measurement methodology as described in Analysis of Electrical Properties Using the four point Probe Method, Waremra et al., E3S Web of Conferences, 73, 13019 (2018), ht-tps: / / doi . org / 10.1051 / e3sconf / 20187313019.

[0497] The etching rate (Re) was calculated using the following formula I:

[0498] n _ di — d2

[0499] e~ t

[0500] formula (I)

[0501] wherein

[0502] Reis the etching rate in A / min,

[0503] d-f is the thickness of the substrate before etching in A,

[0504] d2is the thickness of the substrate after etching in A, and

[0505] t is the etching time in minutes (min).

[0506] In general, an etching rate (Re) of under 10 A / min is a good result and corresponds to a photoresist removal without substantially etching, altering or otherwise negatively affecting the substrate itself.

[0507] 3. Test Methods

[0508] 3.1 General Procedure: Photoresist Stripping Test (test 1 and test 2)

[0509] Photoresist Strip tests were conducted with the prepared photoresist stripping compositions and substrates S1 or S2 respectively according the following general procedure:BASF SE

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[0515] 100 g of the investigated photoresist stripping composition was placed into a 150 mL beaker, which was then placed into a temperature-controlled water bath. Afterwards, the respective substrate S1 or S2 respectively was immersed in the photoresist stripping composition at 60 °C, while being stirred at 500 rpm. After 5, 10 or 15 minutes (see entries in the tables) the tested substrate was first rinsed with deionized water and then with isopropyl alcohol. Lastly, the tested substrate was dried with a stream of nitrogen gas for further analysis, i.e., assessment of photoresist removal as described under 2.1.

[0516] 3.2 General Procedure: Substrate Etching Tests (test 3 and test 4)

[0517] Substrate etching tests were conducted with the prepared photoresist stripping compositions and substrates S3 or S4 respectively according to the following general procedure:

[0518] Before the etching test was performed on substrate S4 (blanket coupon with an ECD copper surface layer of 200 nm thickness) the native oxide layer on the substrate surface was removed with 1% oxalic acid treatment before immersion into the photoresist stripping solutions as described below. The oxalic acid treatment was carried out for 1 min at room temperature (20 °C) followed by rinsing with deionised water and followed by gun drying with nitrogen. The ECD Cu layer thickness di was determined after removal of the native oxide layer. Said pre-treatment process is necessary since the native oxide layer passivates the surface which makes it more immune for etching with alkaline solutions and would thus distort the test results.

[0519] 100 g of the photoresist stripping composition was placed into a 150 mL beaker, which was then placed into a temperature-controlled water bath. The substrates S3 or S4 respectively (substrate S4 as obtained from pre-treatment with oxalic acid as described above) were then immersed in the test solution at 60 °C, while being stirred at 500 rpm. After 15 minutes, the tested substrates were first rinsed with deionized water and then with isopropyl alcohol. Lastly, the tested substrates were dried with a stream of nitrogen gas for further analysis i.e., determination of the etching rate as described under 2.2.

[0520] 4. Test Results of investigated photoresist stripping compositions based on a second stripping component consisting of one or more compounds selected from the group consisting of lactones, lactams and amides (aspect 1):| BASF SE

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[0524] Tables 1 to 4 show both the chemical composition of the photoresist stripping compositions tested and their performances in the respective stripping and etching tests. The following tests were performed:

[0525] Test 1: The photoresist stripping compositions were used in the photoresist stripping tests with S1 as substrate according to the general procedure given under section 3.1 and assessed in terms of photoresist removal as described under 2.1.

[0526] Test 2: The photoresist stripping compositions were used in the photoresist stripping tests with S2 as substrate according to the general procedure given under section 3.1 and assessed in terms of photoresist removal as described under 2.1.

[0527] Test 3: The photoresist stripping compositions were used in the substrate etching tests with S3 as substrate according to the general procedure given under section 3.2 and etching rates have been determined as described under 2.2.

[0528] Test 4: The photoresist stripping compositions were used in the substrate etching tests with S4 as substrate according to the general procedure given under section 3.2 and etching rates have been determined as described under 2.2.

[0529] Table 1. Chemical compositions and test results of photoresist stripping compositions 0 to 6

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[0536] * = not according to the invention

[0537] Table 2. Chemical compositions and test results of photoresist stripping compositions 7 to 12

[0538]

[0539] Table 3. Chemical compositions and test results of photoresist stripping compositions 13 to 19

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[0546] Table 4. Chemical compositions and test results of photoresist stripping compositions 20 to 21

[0547]

[0548] BASF SE

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[0554] All investigated photoresist stripping compositions according to the present invention (No. 7 to No.

[0555] 21) are free of Substances of Very High Concern (SVHC) according to the REACH classification, in particular free of N-methyl-2-pyrrolidone (NMP) and tetramethylammonium hydroxide (TMAH), and are also free of any substance which is classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) and hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. Furthermore, all investigated photoresist stripping compositions according to the present invention are free of DMSO. Photoresist stripping compositions according to the present invention feature a beneficial health and environmental profile. They thus constitute nontoxic, easy to handle and eco-friendly alternatives to state of the art photoresist stripping compositions.

[0556] As can be seen from the results obtained from the photoresist stripping tests 1 and 2 all photoresist stripping compositions according to the present invention (No. 7 to No. 21) show a stripping score of 1 in both tests which indicates that the photoresist was successfully and completely removed from substrates S1 and S2 without any residual material remaining. The positive photoresist layer with a thickness of around 30 pm in substrate S1 as well as the positive photoresist layer with a thickness of around 75 pm in substrate S2 were completely removed within only 10 minutes immersion time under mild conditions of only 60 °C. These results show that photoresist stripping compositions according to the present invention are well suitable for complete removal of photoresist material from a substrate surface, in particular from a substrate featuring a metal surface.

[0557] Stripping compositions not according to the present invention (No. 0 to No. 6) on the other hand show a stripping score of 3 in test 2. Accordingly, removal of the positive photoresist layer with a thickness of around 75 pm in substrate S2 was not successful, as large amounts of photoresist material remained on the substrate surface after 10 minutes immersion time at a temperature of 60 °C.

[0558] Moreover, all investigated photoresist stripping compositions according to the present invention (No.

[0559] 7 to No. 21) had an etching rate (Re) of under 10 A / min in the etching tests 3 and 4 respectively. Neither the aluminium surface of substrate S3 (used in test 4) nor the copper surface of substrate S4 (used in test 4) were substantially etched, altered or otherwise negatively affected when exposed to the photoresist stripping compositions according to the present invention.BASF SE

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[0564]

[0565] The test results show that not only the identification of the right chemical composition was crucial in terms of the performance of the photoresist stripping composition but also the concentration of the solvent NFM, the first stripping component and the second stripping component had to be evaluated and to be considered. The inventors have thus identified the right balance of the three main components of the photoresist stripping composition as defined in the claims which allows i) for an effective and complete removal of photoresist removal and ii) does not substantially etch, alter or otherwise negatively affect the substrate surface.

[0566] In summary, this shows that the photoresist stripping compositions according to the present invention are able to selectively remove photoresist material, in particular positive photoresist material, from a substrate surface without substantially etching, altering or otherwise negatively affecting the substrate itself. Complete photoresist removal even in thick layers of up to 75 m is achieved in a facile and economic process (10 minutes exposure time at 60 °C).

[0567] 5. Water addition test

[0568] Photoresist stripping composition No. 10 according to the present invention was mixed with deionized water in a ratio of 50 wt.% to 50 wt.% in order to investigate the effect of substantial amounts of water in a photoresist stripping formulation. The resulting photoresist stripping composition No. 10-w consisting of 50 wt.% photoresist stripping composition No. 10 and 50 wt.% deionized water was then subjected to tests 1 to 4 as described above.

[0569] The following results were obtained for the photoresist stripping composition No. 10-w:

[0570] Test 1 : stripping score of 3,

[0571] Test 2: stripping score of 1,

[0572] Test 3: etching rate A / min could not be determined because the aluminium surface layer of 30 nm thickness was completely removed,

[0573] Test 4: etching rate of 4.2 A / min.

[0574] Accordingly, the presence of large amounts of water within the photoresist stripping compositions according to the present invention is disadvantageous since etching rates are increased and severe| BASF SE

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[0577]

[0578] etching / erosion effects occur on the metal surface of the investigated substrates, in particular on aluminium surface layers which are widely used in integrated circuits.

[0579] 6. Test Results of investigated photoresist stripping compositions based on a second stripping component consisting of one or more compounds selected from the group consisting of heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups, and ureas (aspect 2)

[0580] Tables 5 to 10 show both the chemical composition of the photoresist stripping compositions tested and their performances in the respective stripping and etching tests. The following tests were performed:

[0581] Test 1: The photoresist stripping compositions were used in the photoresist stripping tests with S1 as substrate according to the general procedure given under section 3.1 and assessed in terms of photoresist removal as described under 2.1.

[0582] Test 3: The photoresist stripping compositions were used in the substrate etching tests with S3 as substrate according to the general procedure given under section 3.2 and etching rates have been determined as described under 2.2.

[0583] Test 4: The photoresist stripping compositions were used in the substrate etching tests with S4 as substrate according to the general procedure given under section 3.2 and etching rates have been determined as described under 2.2.

[0584] Table 6. Chemical compositions & test results of photoresist stripping compositions 1 B to 5B.

[0585]

[0586] | BASF SE

[0587]

[0588] 240899

[0589]

[0590]

[0591] * = example not according to the invention| BASF SE

[0592]

[0593] | 240899

[0594]

[0595] Table 7. Chemical compositions & test results of photoresist stripping compositions 6B to 11 B.

[0596]

[0597] * = example not according to the invention| BASF SE

[0598]

[0599] | 240899

[0600]

[0601] Table 8. Chemical compositions & test results of photoresist stripping compositions 12B to 17B.

[0602]

[0603] | BASF SE

[0604]

[0605] 240899

[0606]

[0607] Table 9. Chemical compositions & test results of photoresist stripping compositions 18B to 23B.

[0608]

[0609] | BASF SE

[0610]

[0611] 240899

[0612]

[0613] Table 10. Chemical compositions & test results of photoresist stripping compositions 24B to 27B.

[0614]

[0615] All investigated photoresist stripping compositions according to the present invention (No. 12B to No.

[0616] 27B) are free of Substances of Very High Concern (SVHC) according to the REACH classification, in particular free of N-methyl-2-pyrrolidone (NMP) and tetramethylammonium hydroxide (TMAH), and are also free of any substance which is classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) according to the Globally Harmonized System of Classific-ation and Labelling of Chemicals (GHS) in the year 2024 and in most cases free of any substance which is classified as hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. Photoresist stripping compositions according to the present invention feature a beneficial health and environmental profile. They thus constitute non-toxic, easy to handle and eco-friendly alternatives to state of the art photoresist stripping compositions.BASF SE

[0617]

[0618] 240899

[0619]

[0620] 240899 WO01

[0621]

[0622] As can be seen from the results obtained from the photoresist stripping test 1 all photoresist stripping compositions according to the present invention (No. 12B to No. 27B) show a stripping score of 1 which indicates that the photoresist was successfully and completely removed from substrate S1 without any residual material remaining. The positive photoresist layer with a thickness of around 75 m in substrate S1 was completely removed within only 5 minutes immersion time under mild conditions of only 60 °C. These results show that photoresist stripping compositions according to the present invention are well suitable for complete removal of thick layers of photoresist material from a substrate surface, in particular from a substrate featuring a metal surface.

[0623] Stripping compositions not according to the present invention (No. 1 B to No. 11 B) on the other hand in almost all cases show a stripping score of 3 in test 1. Accordingly, removal of the positive photoresist layer with a thickness of around 75 pm in substrate S1 was not successful, as in most cases large amounts of photoresist material remained on the substrate surface after 5 minutes or even 10 minutes of immersion time at a temperature of 60 °C.

[0624] Moreover, all investigated photoresist stripping compositions according to the present invention (No.

[0625] 12B to No. 27B) had an etching rate (Re) of under 5 A / min in the etching tests 3 and 4 respectively. Neither the aluminium surface of substrate S3 (used in test 3) nor the copper surface of substrate S4 (used in test 4) were substantially etched, altered or otherwise negatively affected when exposed to the photoresist stripping compositions according to the present invention.

[0626] The test results show that not only the identification of the right chemical composition was crucial in terms of the performance of the photoresist stripping composition but also the concentration of the solvent mixture, the first stripping component and the second stripping component had to be evaluated and to be considered. The inventors have thus identified the right balance of the three main components of the photoresist stripping composition as defined in the claims which allows i) for an effective and complete removal of photoresist material and ii) does not substantially etch, alter or otherwise negatively affect the substrate surface.

[0627] Stripping compositions not according to the present invention (No. 1 B to No. 11 B) on the other hand had very high etching rates (Re) of up to 59.8 A / min (example No. 8B). Accordingly, they substantially etched, altered or otherwise negatively affected the substrate surface, in particular substantially etched metal surfaces, in particular severe etching of copper surfaces was observed.BASF SE

[0628]

[0629] 240899

[0630]

[0631] 240899

[0632]

[0633] This shows that the presence of primary and / or secondary amines such as diglycolamine and / or the presence of quaternary ammonium compounds such as tetramethylammonium hydroxide (TMAH) is disadvantageous in terms of metal substrate compatibility. Accordingly, the photoresist stripping compositions according to the present invention are superior to photoresist stripping compositions known in the art which in most cases rely on the presence of primary and / or secondary amines or the presence of quaternary ammonium compounds.

[0634] In summary, this shows that the photoresist stripping compositions according to the present invention selectively remove photoresist material, in particular positive photoresist material, from a substrate surface without substantially etching, altering or otherwise negatively affecting the substrate itself. Complete photoresist removal even in thick layers of up to 75 pm is achieved in a facile and economic process (5 minutes exposure time at 60 °C).

[0635] 7. Water addition tests

[0636] Selected photoresist stripping composition No. 15B (abbreviated as PSC No. 15B in table 11) according to the present invention was mixed with deionized water in different ratios in order to investigate the effect of substantial amounts of water in a photoresist stripping formulation. The resulting photoresist stripping compositions were then subjected to tests 1, 3 and 4 as described above. The test results are depicted in table 11 below.

[0637] Table 11. Water addition test.

[0638]

[0639] As can be seen from the test results the presence of large amounts of water within the photoresist stripping compositions according to the present invention is disadvantageous since etching rates areBASF SE

[0640]

[0641] 240899

[0642]

[0643] 240899 WO01

[0644]

[0645] increased and severe etching / erosion effects occur on the metal surface of the investigated substrates, in particular on copper surface layers which are widely used in integrated circuits.

[0646] Moreover all photoresist stripping compositions which were mixed with deionized water were not stable. In particular gas evolution was observed, most likely due to a reaction of propylene carbonate with water under CO2formation. The presence of substantial amounts of water within the photoresist stripping compositions thus also reduces the (long term) stability. The strength of this effect essentially depends on the selection of the second stripping component and might in some cases be more or less pronounced.

[0647] Accordingly it is preferred that the photoresist stripping composition according to the present invention contains less than 30.0 wt.% of water, preferably less than 20.0 wt.% of water.

[0648] 8. Test Results of investigated photoresist stripping compositions based on triethanolamine as first stripping component

[0649] Tables 12 to 14 show both the chemical composition of the photoresist stripping compositions tested and their performances in the respective stripping and etching tests. The following tests were performed:

[0650] Test 1: The photoresist stripping compositions were used in the photoresist stripping tests with S1 as substrate according to the general procedure given under section 3.1 and assessed in terms of photoresist removal as described under 2.1.

[0651] Test 2: The photoresist stripping compositions were used in the photoresist stripping tests with S2 as substrate according to the general procedure given under section 3.1 and assessed in terms of photoresist removal as described under 2.1. Stripping test 2 was only performed for selected photoresist stripping compositions, results are nevertheless representative for all inventive photoresist stripping compositions.

[0652] Test 3: The photoresist stripping compositions were used in the substrate etching tests with S3 as substrate according to the general procedure given under section 3.2 and etching rates have been determined as described under 2.2.| BASF SE

[0653]

[0654] 240899

[0655]

[0656] Test 4: The photoresist stripping compositions were used in the substrate etching tests with S4 as substrate according to the general procedure given under section 3.2 and etching rates have been determined as described under 2.2.

[0657] If a photoresist stripping composition did not show good test results in the photoresist stripping test(s), i.e. a stripping score of 3 in one of tests 1 or 2, or the etching test(s), i.e. high etching rates in one tests 3 or 4, not all tests were performed in some cases (see entries labelled with n.d. = not determined in the tables).

[0658] Table 12. Chemical compositions & test results of photoresist stripping compositions 1C to 6C

[0659]

[0660] * = example not according to the invention| BASF SE

[0661]

[0662] | 240899

[0663]

[0664] Table 13. Chemical compositions & test results of photoresist stripping compositions 7C to 12C

[0665]

[0666] * = example not according to the invention| BASF SE

[0667]

[0668] | 240899

[0669]

[0670] Table 14. Chemical compositions & test results of photoresist stripping compositions 13C to 15C

[0671]

[0672] * = example not according to the inventionBASF SE

[0673]

[0674] 240899

[0675]

[0676] 240899 WO01

[0677]

[0678] All investigated photoresist stripping compositions according to the present invention (No. 7C to No.

[0679] 15C) are free of Substances of Very High Concern (SVHC) according to the REACH classification, in particular free of N-methyl-2-pyrrolidone (NMP) and tetramethylammonium hydroxide (TMAH), and are also free of any substance which is classified as acute toxic, category 1 to 3 (GHS06), health hazardous, category 1, 1A, 1B (GHS08) and hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024. Photoresist stripping compositions according to the present invention feature a beneficial health and environmental profile. They thus constitute non-toxic, easy to handle and eco-friendly alternatives to state of the art photoresist stripping compositions.

[0680] As can be seen from the results obtained from the photoresist stripping test 1 all photoresist stripping compositions according to the present invention (No. 7C to No. 15C) show a stripping score of 1 which indicates that the photoresist was successfully and completely removed from substrate S1 without any residual material remaining. The positive photoresist layer with a thickness of around 30 pm in substrate S1 was completely and selectively removed within only 5 or 10 minutes immersion time under mild conditions of only 60 °C. These results show that photoresist stripping compositions according to the present invention are well suitable for complete removal of photoresist material from a substrate surface, in particular from a substrate featuring a metal surface.

[0681] As can be seen from the results obtained from the photoresist stripping test 2 - conducted with the more challenging substrate S2 featuring a positive photoresist layer with a thickness of around 75 pm - all exemplary investigated photoresist stripping compositions according to the present invention show a stripping score of 1 (or a stripping score of at least 2 in one case) which indicates that the photoresist was successfully and completely removed from substrate S2 without any residual material remaining (or with only traces remaining in the case of one example). The positive photoresist layer with a thickness of around 75 pm in substrate S2 could be completely and selectively removed within only 10 or 15 minutes immersion time under mild conditions of only 60 °C. These results show that photoresist stripping compositions according to the present invention are well suitable for complete removal of a thick layer of photoresist material from a substrate surface, in particular from a substrate featuring a metal surface.

[0682] Exemplary stripping compositions not according to the present invention (No. 1C to No. 6C) on the other hand show a stripping score of 3 in test 1 and / or 2. Accordingly, removal of the positive photoresist layer with a thickness of around 30 pm in substrate S1 and / or with a thickness of aroundBASF SE

[0683]

[0684] 240899

[0685]

[0686] 240899 WO01

[0687]

[0688] 75 m in substrate S2 was not successful, as in most cases large amounts of photoresist material remained on the substrate surface after 5 or 10 minutes immersion time at a temperature of 60 °C.

[0689] Moreover, all investigated photoresist stripping compositions according to the present invention (No.

[0690] 7C to No. 15C) had an etching rate (Re) of under 6 A / min in the etching tests 3 and 4 respectively. Neither the aluminium surface of substrate S3 (used in test 3) nor the copper surface of substrate S4 (used in test 4) were substantially etched, altered or otherwise negatively affected when exposed to the photoresist stripping compositions according to the present invention. It has been found that in particular triethanolamine is a very mild and selective etching agent which is well suitable for substrates featuring a metal surface wherein the metal should remain intact. Slightly longer immersion times of 10 to 15 minutes for complete removal of thick photoresist layers with a thickness of 75 pm and more are thus more than acceptable.

[0691] The test results show that not only the identification of the right chemical composition was crucial in terms of the performance of the photoresist stripping composition but also the concentration of the solvent mixture, the first stripping component and the second stripping component had to be evaluated and to be considered. The inventors have thus identified the right balance of the three main components of the photoresist stripping composition as defined in the claims which allows I) for an effective and complete removal of photoresist removal and ii) does not substantially etch, alter or otherwise negatively affect the substrate surface.

[0692] Stripping compositions not according to the present invention (No. 1C to No. 6C) on the other hand had very high etching rates (Re) of up to 51.8 A / min (example No. 4C). Accordingly, they substantially etched, altered or otherwise negatively affected the substrate surface, in particular substantially etched metal surfaces.

[0693] The test results in particular demonstrate the excellent performance of photoresist stripping composition comprising a first stripping component as defined in the claims and as defined and described herein.

[0694] It has been proven particularly suitable and effective when the first stripping component consists of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group, wherein the one or at least one of the more than one alkanolamines featuring a tertiaryBASF SE

[0695]

[0696] 240899

[0697]

[0698] amino group contains 1 to 6 hydroxy groups and / or has a molar mass in a range from 100 g / mol to 1000 g / mol.

[0699] A good and representative example of such an alkanolamine compound featuring a tertiary amino group is triethanolamine which has shown excellent performance in photoresist removal in a wide variety of tested photoresist stripping compositions.

[0700] In summary, this shows that the photoresist stripping compositions according to the present invention selectively remove photoresist material, in particular positive photoresist material, from a substrate surface without substantially etching, altering or otherwise negatively affecting the substrate itself. Complete photoresist removal even in thick layers of up to 75 m is achieved in a facile and economic process (10 to 15 minutes exposure time at 60 °C).

[0701] BRIEF DESCRIPTION OF THE DRAWINGS

[0702] Further advantages, features and details of the invention result from the following description of the preferred embodiments as well as from the drawings. In the following, a summary of the figures is given.

[0703] Fig. 1 is a schematic cross section of substrate S1 and also illustrates the removal of the photoresist by stripping.

[0704] Fig. 2 is a schematic cross section of substrate S2 and also illustrates the removal of the photoresist by stripping.

[0705] Fig. 3 shows LSM images of substrate surfaces after complete photoresist removal by stripping. The images are used as a reference to assign a stripping score of 1.

[0706] Fig. 4 shows LSM images of substrate surfaces after substantial photoresist removal by stripping. The images are used as a reference to assign a stripping score of 2.

[0707] Fig. 5 shows LSM images of substrate surfaces after incomplete photoresist removal by stripping. The images are used as a reference to assign a stripping score of 3.BASF SE

[0708]

[0709] 240899

[0710]

[0711] 240899 WO01

[0712]

[0713] Fig. 6 shows LSM images of substrate surfaces including photoresist layer prior to application of a photoresist stripping composition.

[0714] DETAILED DESCRIPTION OF THE DRAWINGS

[0715] Fig. 1 shows a schematic cross-section of substrate S1 100 to the left of the arrow. The substrate 51 comprises a surface layer of physical vapour deposited copper (PVD Ou surface layer) 101, on which electrochemically deposited copper pillars (ECD Ou pillars) 102 and photoresist material 103 are deposited in an alternating pattern. The ECD Ou pillars 102 have a thickness of around 25 m, while the photoresist material 103 is present in a thickness of around 30 pm. Substrate S1 100 is contacted with a photoresist stripping composition according to the invention in a process of removing photoresist material from the substrate 300, which is represented by the arrow. The treated substrate is depicted on the right side of the arrow. The schematic cross-section of said treated substrate shows that the photoresist material 103 is completely removed while the PVD Ou surface layer 101 and the ECD Cu pillars 102 are not effected from the etching process and thus remain unaltered.

[0716] Fig. 2 shows a schematic cross-section of substrate S2200 to the left of the arrow. The substrate 52 comprises a surface layer of physical vapour deposited copper (PVD Cu surface layer) 201, on which electrochemically deposited copper pillars (ECD Cu pillars) 202 and photoresist material 203 are deposited in an alternating pattern. The ECD Cu pillars 202 have a thickness of around 65 m, while the photoresist material 203 is present in a thickness of around 75 pm. Substrate S2 200 is contacted with a photoresist stripping composition according to the invention in a process of removing photoresist material from the substrate 300, which is represented by the arrow. The treated substrate is depicted on the right side of the arrow. The schematic cross-section of said treated substrate shows that the photoresist material 203 is completely removed while the PVD Cu surface layer 201 and the ECD Cu pillars 202 are not effected from the etching process and thus remain unaltered.

[0717] Fig. 3 shows in Fig. 3(a-c) the laser scanning microscope (LSM) images of three different substrates after complete removal of photoresist material obtained upon treatment with a photoresist stripping composition according to the present invention and subsequent drying. The LSM image of substrate 51 after complete removal of photoresist material in Fig. 3(a) as well as the LSM images of substrate 52 after complete removal of photoresist material in Fig. 3(b) and Fig. 3(c) respectively were taken under 5x magnification. The rectangles within the LSM images derive from the software which automatically identifies an area for deeper analysis at 50x magnification (not depicted in Fig. 3). As canBASF SE

[0718]

[0719] 240899

[0720]

[0721] 240899 WO01

[0722]

[0723] be seen from the LSM images the substrate surface in each case is entirely free of photoresist. This appearance corresponds to a stripping score of 1.

[0724] Fig.4 shows in Fig.4(a-c) the laser scanning microscope (LSM) images of three different substrates after removal of photoresist material obtained upon treatment with a photoresist stripping composition and subsequent drying. The LSM image of substrate S1 after removal of photoresist material in Fig.

[0725] 4(a) as well as the LSM images of substrate S2 after removal of photoresist material in Fig. 4(b) and Fig. 4(c) respectively were taken under 5x magnification. The rectangles within the LSM images derive from the software which automatically identifies an area for deeper analysis at 50x magnification (not depicted in Fig. 4). As can be seen from the LSM images the majority of photoresist was removed from the substrate surface, however, traces of photoresist material remained 401. This appearance corresponds to a stripping score of 2.

[0726] Fig. 5 shows in Fig. 5(a-d) the laser scanning microscope (LSM) images of four different substrates after treatment with a photoresist stripping composition not according to the present invention and subsequent drying. The LSM image of substrate S1 after treatment as depicted in Fig. 5(a) as well as the LSM images of substrate S2 after treatment as depicted in Fig. 5(b), Fig. 5(c) and Fig. 5(d) respectively were taken under 5x magnification. The rectangles within the LSM images derive from the software which automatically identifies an area for deeper analysis at 50x magnification (not depicted in Fig. 5). As can be seen from the LSM images photoresist removal was not successful, resulting in the residual presence of large amounts of photoresist material on the substrate surface 501. This appearance corresponds to a stripping score of 3.

[0727] Fig. 6 shows in Fig. 6(a-b) the laser scanning microscope (LSM) images of two different substrates including photoresist layer as received from a supplier. Fig. 6(a) shows the LSM image of substrate S1 as received prior to treatment with a photoresist stripping composition under 5x magnification.

[0728] Fig. 6(b) shows the LSM image of substrate S2 as received prior to treatment with a photoresist stripping composition under 5x magnification. The rectangles within the LSM images derive from the software which automatically identifies an area for deeper analysis at 50x magnification (not depicted in Fig. 6).

[0729] List of Reference Signs:

[0730] 100 schematic cross-section of substrate S1| BASF SE

[0731]

[0732] | 240899

[0733]

[0734] 101 surface layer of physical vapour deposited copper (PVD Cu surface layer) in S1

[0735] 102 electrochemically deposited copper pillars (ECD Cu pillars) in S1

[0736] 103 photoresist material in a thickness of around 30 pm in S1

[0737] 200 schematic cross-section of substrate S2

[0738] 201 surface layer of physical vapour deposited copper (PVD Cu surface layer) in S2

[0739] 202 electrochemically deposited copper pillars (ECD Cu pillars) in S2

[0740] 203 photoresist material in a thickness of around 75 pm in S2

[0741] 300 process of removing photoresist material from the substrate with a photoresist stripping composition according to the invention

[0742] 401 remaining traces of photoresist material on the substrate surface

[0743] 501 large amounts of photoresist material on the substrate surface

Claims

BASF SE240899240899 WO01CLAIMS1. A photoresist stripping composition for removing photoresist material from a substrate, the photoresist stripping composition comprising- N-Formylmorpholine (NFM) as solvent,N-Formylmorpholine (NFM) being present in a concentration of 15 wt.% to 85 wt.% in the photoresist stripping composition,and- a first stripping component consisting of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group,the first stripping component being present in a concentration of 3 wt.% to 50 wt.% in the photoresist stripping composition,and- a second stripping component consisting of one or more compounds selected from the group consisting of lactones, lactams and amides, or consisting of one or more compounds selected from the group consisting of heterocyclic cycloalkanones, carbonate esters, carbamates, acyclic carboxylic esters, ethers not containing any tertiary amino groups, and ureas,the second stripping component being present in a concentration of 5 wt.% to 60 wt.% in the photoresist stripping composition,wherein the photoresist stripping composition is free of N-Methyl-2-pyrrolidone (NMP), Tetramethylammonium hydroxide (TMAH) and dimethyl sulfoxide (DMSO).

2. The photoresist stripping composition according to claim 1, wherein the photoresist stripping composition contains less than 30.0 wt.% of water, preferably less than 20.0 wt.% of water, more preferably less than 10.0 wt.% of water.BASF SE240899240899 WO013. The photoresist stripping composition according to any of the preceding claims, wherein the first stripping component comprises or consists of one or more compounds selected from the group consisting of alkanolamines featuring a tertiary amino group, wherein- the one or at least one of the more than one alkanolamines featuring a tertiary amino group contains 1 to 6 hydroxy groups, preferably 1 to 5 hydroxy groups, more preferably 1 to 4 hydroxy groups, even more preferably 1 to 3 hydroxy groups,and / or- the one or at least one of the more than one alkanolamines featuring a tertiary amino group has a molar mass in a range from 100 g / mol to 1000 g / mol, preferably in a range from 100 g / mol to 800 g / mol, more preferably in a range from 100 g / mol to 600 g / mol, even more preferably in a range from 100 g / mol to 400 g / mol, most preferably in a range from 100 g / mol to 250 g / mol,and / or- the one or at least one of the more than one alkanolamines featuring a tertiary amino group has one tertiary amino group and wherein one, two or three of the N-substituents of said one tertiary amino group are individually and independently selected from the group consisting of- linear or branched alkyls, preferably the linear or branched alkyl is methyl, ethyl, propyl, butyl, pentyl or hexyl, more preferably methyl, ethyl, propyl or butyl,- linear or branched hydroxyalkyls, preferably the linear or branched hydroxyalkyl is a monohydroxyalkyl, more preferably is hydroxymethyl, hydroxyethyl, hydroxypropyl or hydroxybutyl,- linear or branched hydroxyalkylether groups such as ethoxyethanol (-CH2-CH2-O-CH2-CH2- OH).

4. The photoresist stripping composition according to any of the preceding claims, wherein- N-Formylmorpholine (NFM) is present in a concentration of 20 wt.% to 80 wt.%, preferably in a concentration of 25 wt.% to 75 wt.%, in the photoresist stripping composition,and / or| BASF SE| 240899- the first stripping component is present in a concentration of 4 wt.% to 45 wt.%, preferably in a concentration of 5 wt.% to 40 wt.%, in the photoresist stripping composition,and / or- the second stripping component is present in a concentration of 7 wt.% to 55 wt.%, preferably in a concentration of 10 wt.% to 50 wt.%, in the photoresist stripping composition.

5. The photoresist stripping composition according to any of the preceding claims, wherein- the mass ratio of N-Formylmorpholine (NFM) to the first stripping component is in a range of from 10:1 to 1:4, preferably in a range of from 9:1 to 1:3, more preferably in a range of from 8:1 to 1:2,and / or- the mass ratio of N-Formylmorpholine (NFM) to the second stripping component is in a range of from 7:1 to 1:5, preferably in a range of from 6:1 to 1:4, more preferably in a range of from 5:1 to 1:3,and / or- the mass ratio of the first stripping component to the second stripping component is in a range of from 4:1 to 1:7, preferably in a range of from 3:1 to 1:6, more preferably in a range of from 2:1 to 1:5,and / or- the mass ratio of N-Formylmorpholine (NFM) to the first and second stripping component is in a range of from 5:1 to 1:5, preferably in a range of from 4:1 to 1:4, more preferably in a range of from 3:1 to 1:3.

6. The photoresist stripping composition according to any of the preceding claims, wherein the first stripping component comprises or consists of- one or more alkanolamines featuring a dimethylamino group, preferably comprises or consists of 2-[2-(Dimethylamino)ethoxy]ethanol and / or 2-Dimethylamino-2-methylpropan-1-ol, more preferably the first stripping component is 2-[2-(Dimethylamino)ethoxy]ethanol,BASF SE240899240899 WO01and / or- one or more alkanolamines featuring a tertiary amino group containing three hydroxy groups (triols), preferably comprises or consists of trimethanolamine, triethanolamine (TEA), tris(3-hydroxypro-pyl)amine and / or triisopranolamine, more preferably comprises or consists of triethanolamine (TEA).

7. The photoresist stripping composition according to any of the preceding claims, wherein the second stripping component comprises or consists of- one or more lactones, preferably comprises or consists of one or more substituted or unsubstituted valerolactones and / or one or more substituted or unsubstituted butyrolactones, more preferably comprises or consists of gamma-valerolactone (GVL), gamma-butyrolactone (GBL), 5-tetrahydrofuran-2-yl-tetrahydrofuran-2-one (y-THF-Butyrolactone) and / or p-Methyl-5-valerolactone (BMVL),and / or- one or more substituted or unsubstituted valerolactams and / or one or more substituted or unsubstituted butyrolactams, more preferably comprises or consists of hydroxyethylpyrrolidone (HEP),and / or- one or more amides, preferably comprises or consists of one or more substituted or unsubstituted N, N-dialkyl amides, more preferably comprises or consists of one or more substituted or unsubstituted N,N-dimethyl amides, most preferably comprises or consists of N,N-dimethylpropionamide and / or 2-Hydroxy-N,N-dimethylpropanamide.

8. The photoresist stripping composition according to any of the preceding claims, wherein the second stripping component comprises or consists of- one or more heterocyclic cycloalkanones, preferably comprises or consists of one or more oxygenheterocyclic cycloalkanones, more preferably comprises or consists of one or more substituted or unsubstituted, monocyclic or bicyclic oxygen-heterocyclic cycloalkanones, even more preferably comprises or consists of one or more substituted or unsubstituted, monocyclic or bicyclic, five- toBASF SE240899240899 WO01eight-membered oxygen-heterocyclic cycloalkanones most preferably comprises or consists of di-hydrolevoglucosenone,and / or- one or more carbonate esters, preferably comprises or consists of one or more substituted or unsubstituted cyclic carbonate esters, more preferably comprises or consists of one or more substituted or unsubstituted five-membered cyclic carbonate esters, even more preferably comprises or consists of propylene carbonate,and / or- one or more carbamates, preferably comprises or consists of one or more substituted or unsubstituted cyclic carbamates, more preferably comprises or consists of one or more substituted or unsubstituted five-membered cyclic carbamates, even more preferably comprises or consists of 3-methyl-oxazolidin-2-one,and / or- one or more acyclic carboxylic esters, preferably comprises or consists of one or more acyclic alkyl esters and / or acyclic ketoesters, more preferably comprises or consists of one or more C1 to C4 alkyl ketoesters, even more preferably comprises or consists of methyl levulinate,and / or- one or more ethers not containing any tertiary amino groups, preferably comprises or consists of one or more glycol ethers, more preferably comprises or consists of ethylene and / or propylene glycol ethers with a maximum number of 5 ethylene oxide (EO) units and / or propylene oxide (PO) units, even more preferably comprises or consists of di(propylene glycol) methyl ether and / or diethylene glycol diethyl ether,and / or- one or more ureas, preferably comprises or consists of one or more substituted or unsubstituted cyclic ureas, more preferably comprises or consists of one or more substituted or unsubstituted fivemembered cyclic ureas, even more preferably comprises or consists of 1 ,3-dimethyl-2-im-idazolidinone.BASF SE240899240899 WO019. The photoresist stripping composition according to any of the preceding claims, wherein the photoresist stripping composition is essentially free, preferably is completely free, of- any quaternary ammonium compounds, in particular quaternary ammonium hydroxides,and / or- any amines classified as acute toxic, category 1 to 3 (GHS06) or health hazardous, category 1, 1A, 1B (GHS08) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024, in particular free of 3,3'-lminobis(N, N-dimethylpropylamine), diethyl-entriamine, triethylenetetramine, N,N,N',N'-Tetramethyl-1,6-hexanediamine and tetraethylenepentamine (TEPA).

10. The photoresist stripping composition according to any of the preceding claims, wherein the photoresist stripping composition is essentially free, preferably is completely free of any substance which is classified as acute toxic, category 1 to 3 (GHS06) or health hazardous, category 1, 1A, 1B (GHS08) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024, more preferably the photoresist stripping composition is also essentially or completely free of any substance which is classified as hazardous to the aquatic environment, category 1 or 2 (GHS09) according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in the year 2024.

11. The photoresist stripping composition according to any of the preceding claims, wherein- the photoresist stripping composition when present in the form of a 10 wt.-% solution in deionized water has a pH-value in the range of from 9.0 to 12.0, preferably in a range of from 9.5 to 11.5, more preferably in a range of from 10.0 to 11.3,and / or- the photoresist stripping composition has a flash point of at least 45 °C, preferably of at least 50 °C, more preferably of at least 60 °C.BASF SE240899240899 WO0112. Use of 2-[2-(Dimethylamino)ethoxy]ethanol and / or 2-Dimethylamino-2-methylpropan-1-ol, preferably use of 2-[2-(Dimethylamino)ethoxy]ethanol, as compound in a photoresist stripping composition comprising N-Formylmorpholine (NFM), preferably in a photoresist stripping composition according to any of claims 1 to 11, for removing photoresist material from a substrate.

13. Use of a photoresist stripping composition according to any of claims 1 to 11 for removing photoresist material from a substrate, preferably- for removing positive photoresist material from a substrate, more preferably for removing photoresist material comprising or consisting of thermoplastic (co-)polymer,and / or- for removing photoresist material from a substrate with a metal surface.

14. A process of removing photoresist material from a substrate, the process at least comprising the following steps:i) providing or preparing a substrate comprising photoresist material on the substrate surfaceii) providing or preparing a photoresist stripping composition according to any of claims 1 to 11,iii) contacting the substrate comprising photoresist material on the substrate surface with the provided or prepared photoresist stripping composition, so that the photoresist material is at least partly, preferably completely, removed from the substrate surface.

15. A process for the production of an integrated circuit, comprising the process according to claim 14.

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