Rational solvent formulation for hardened photoresist removal

Abstract

The present invention provides a solvent composition formulated to dissolve hardened photoresist on a semiconductor surface.SOLUTION: The solvent composition includes about 1 to 30 wt.% of at least one alkanolamine, about 10 to 95 wt.% of at least one ethylene glycol ether, and 0 to about 1 wt.% of an N, N-disubstituted hydroxylamine. The N, N-disubstituted hydroxylamine is selected on the basis of at least one alkanolamine. Specifically, the N, N-disubstituted hydroxylamine is alkanol substituted in any solvent composition comprising N-methyldiethanolamine.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to rational solvent formulations for hardened photoresist removal, particularly to solvent compositions.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 678,930, filed August 2, 2024, which is incorporated herein by reference in its entirety. [Background technology]

[0003] Semiconductor photolithography is a mature and sophisticated technology used to fabricate integrated electronic devices with exceptionally sophisticated and small geometries. The fundamental step in most photolithography processes is the selective photochemical hardening of a resinous photoresist layer. The photoresist is applied as a blanket over an entire semiconductor wafer or die portion of the wafer and cured by ultraviolet light projected through an optical mask. Through photopolymerization and / or photocrosslinking, selected areas of the layer are hardened in the pattern defined by the optical mask. The unhardened portions of the layer (e.g., areas beneath opaque features of the mask) are washed away with a solvent, leaving behind a photohardened pattern of the protected areas.

[0004] Subsequent processing can vary from implementation to implementation. In some implementations, the semiconductor wafer or die is subjected to dielectric or semiconductor etching conditions that etch only areas not covered by the hardened photoresist. Alternatively or additionally, the semiconductor wafer or die can undergo one or more additional processes in which metal or additional semiconductor material is grown (electrochemically, epitaxially, or otherwise) that adheres only to areas not protected by the hardened photoresist.

[0005] In these and other variations, subsequent processing typically requires removal of all portions of the hardened photoresist on the surface of the wafer or die, and appropriately formulated solvent compositions can be used to that effect.

[0006] For example, Patent Document 1 discloses a cleaning composition for removing residues and contaminants from microelectronic devices having them on their surfaces, the cleaning composition comprising at least one complexing agent, at least one cleaning additive, at least one pH adjuster, water, and at least one oxylamine compound or a salt thereof. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Patent Application Publication No. 2020 / 199,500 Summary of the Invention [Means for solving the problem]

[0008] One aspect of the present disclosure relates to a solvent composition formulated to dissolve hardened photoresist on a semiconductor surface. The solvent composition comprises approximately 1 to 30% by weight of at least one alkanolamine, approximately 10 to 95% by weight of at least one ethylene glycol ether, and 0 to approximately 1% by weight of an N,N-disubstituted hydroxylamine. The N,N-disubstituted hydroxylamine is selected based on the at least one alkanolamine. Specifically, the N,N-disubstituted hydroxylamine is alkanol-substituted in any solvent composition containing N-methyldiethanolamine.

[0009] This Summary is provided to introduce a selection of concepts in a simplified form that are further described in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all of the disadvantages noted anywhere in this disclosure. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 shows the molecular structures of exemplary alkanolamines. [Figure 2] FIG. 1 shows the molecular structure of an exemplary ethylene glycol ether. [Figure 3] FIG. 1 shows the molecular structures of exemplary N,N-disubstituted hydroxylamines. [Figure 4] FIG. 4 shows the molecular structures of additional exemplary compounds that do not belong to any of the classes represented in FIG. 1, FIG. 2, or FIG. 3. [Figure 5] FIG. 1 shows a hardened photoresist-like polymer along with a Hansen Solubility Parameter (HSP) spatial representation of the polymer with three different solvents. [Figure 6] FIG. 1 illustrates aspects of an exemplary evaluation method applicable to solvent compositions herein. DETAILED DESCRIPTION OF THE INVENTION

[0011] As noted above, photolithography uses specific solvent compositions to remove hardened photoresist after selective etching and / or selective application steps. Generally, solvent compositions are selected based on their ability to swell, soften, and / or dissolve hardened photoresist, including one or more crosslinked polymers. In some embodiments, solvent compositions are selected further based on the degree of degradation they may cause to various additional structures (e.g., metal or epitaxial semiconductor features) on the semiconductor wafer or die surface during hardened photoresist removal. For example, very aggressive solvent compositions that may etch or remove the additional features are generally undesirable. In some scenarios, effective dissolution of hardened photoresist and inertness toward the additional features are not unrelated, but are linked in the following way: a desirable solvent composition may be one that does not appreciably degrade the additional features within the time required for the composition to completely dissolve and wash away the hardened photoresist.

[0012] Unfortunately, semiconductor photolithography technology, developed over the years, has not given sufficient consideration to the health and ecological impact of the solvent compositions used therein. In particular, N-methyl-2-pyrrolidine (NMP), a component of some solvent compositions used to remove hardened photoresist, has recently been classified as a substance of very high concern (SVHC) under the EU's REACH (Registration, Authorization, and Restriction of Chemicals) regulation.

[0013] The present disclosure addresses the above-mentioned problems and provides further advantages in the field of semiconductor photolithography. The present disclosure presents a class of solvent compositions that are highly effective at removing hardened photoresist, yet relatively inert toward additional structures, including at least copper. Significantly, such solvent compositions do not contain NMP. The present disclosure also presents a rational approach to formulating solvent compositions that can be used to dissolve hardened photoresist, based on theoretical models of polymer solvation and swelling energetics.

[0014]

[0004] Referring now to the drawings, the inventors herein have investigated certain classes of chemical compounds as components of solvent compositions intended to dissolve hardened photoresists. Figures 1-4 show the molecular structures of exemplary compounds in each class. The figures also show, where available, the Chemical Abstracts Service (CAS) registry numbers of the exemplified compounds.

[0015] Figure 1 shows the molecular structures of exemplary alkanolamines. MEA represents monoethanolamine. A-2 represents N-methylethanolamine. A-3 represents methyldiethanolamine.

[0016] Figure 2 shows the molecular structures of exemplary ethylene glycol ethers. BDG stands for diethylene glycol monobutyl ether, EDG stands for diethylene glycol monoethyl ether, and MDG stands for diethylene glycol monomethyl ether.

[0017] Figure 3 shows the molecular structures of exemplary N,N-disubstituted hydroxylamines. DEHA stands for N,N-diethylhydroxylamine. C-2 stands for N,N-diethanolhydroxylamine.

[0018] FIG. 4 shows molecular structures of additional exemplary compounds that do not belong to any of the classes depicted in FIG. 1, FIG. 2, or FIG. 3. Some of the depicted compounds are polar protic compounds. Some of the depicted compounds are polar aprotic compounds. Some of the depicted compounds are alcohols or polyols, and one depicted compound is a quaternary ammonium hydroxide. MMB stands for 3-methoxy-3-methylbutanol. MB stands for 3-methoxy-1-butanol. PC stands for propylene carbonate. 2-P stands for 2-pyrrolidone. PG stands for propylene glycol. NMP stands for N-methyl-2-pyrrolidone. DMSO stands for dimethyl sulfoxide. TMAH stands for tetramethylammonium hydroxide.

[0019] As noted above, the function of the solvent composition is to swell, soften, and / or dissolve regions of the cured photoresist. To begin a rational search for an effective solvent composition, preliminary solvent testing was performed using 46 micrometer (μm) thick cured photoresist. Cleaning was performed in the solvent composition maintained at 70°C and agitated at 500 revolutions per minute (rpm). This preliminary testing revealed the following cleaning times for mixtures containing NMEA and a series of different cosolvents: 8 minutes with a cosolvent containing 2% TMAH, 76.7% DMSO, and other solvents; 7 minutes with a cosolvent containing MMB; 7 minutes with a cosolvent containing MB; over 10 minutes with a cosolvent containing PC; 8 minutes with a cosolvent containing 2-P; 3.5 minutes with a cosolvent containing BDG; 3.5 minutes with a cosolvent containing EDG; and 4 minutes with a cosolvent containing MDG. As indicated by this preliminary data, the best-performing cosolvents were EDG and BDG.

[0020] To investigate the rationale for these effects, the Hansen Solubility Parameter (HSP) model for the cosolvents was compared with the corresponding parameters of the polymer model for the first-hardening photoresist PR1, a methacrylate polymer. First-hardening photoresist PR1 is commercially available from Tokyo Ohka Kogyo Co., Ltd. under the product identifier CR-4000.

[0021] For context, the Hansen Solubility Parameter (HSP) is a value used to predict the solubility of materials, primarily polymers and solvents, based on intermolecular interactions. Developed by Charles M. Hansen in 1967, HSP predicts the solubility of a substance through the dispersion force parameter δD, the polar force parameter δP, and the hydrogen bonding parameter δH. Dispersion forces (e.g., London forces) are relatively weak nonpolar interactions that exist between all molecules. The δD parameter represents the contribution of dispersion forces to the overall solubility. Polar forces result from dipole-dipole interactions between polar molecules. The δP parameter represents the contribution of polar interactions to solubility. The hydrogen bonding parameter δH describes the hydrogen bonding interactions that occur when hydrogen is bonded to negatively charged atoms such as oxygen, nitrogen, or fluorine. The δH parameter reflects the extent to which hydrogen bonding affects solubility.

[0022] HSP parameters may be represented in a three-dimensional space, with each substance positioned based on its δD, δP, and δH values. The distance between points in this space, the Hansen distance Ra, can be used to determine the likelihood of one substance dissolving in another. A smaller Ra value indicates better solubility. In general, HSP provides a valuable model for understanding and predicting solubility, facilitating the selection of compatible materials in many technological fields.

[0023] FIG. 5 shows an idealized representation of a polymer similar to a hardened photoresist, along with an HSP space representation of the polymer and three different solvents. While FIG. 5 shows polyhydroxyethyl methacrylate (pHEMA) as an example of a polymer used in hardened photoresist PR1, it is understood that different and / or other polymers may be present in the hardened photoresist and may be removed by the solvents described herein. It is understood that in the pHEMA model of FIG. 5, n and m can take on a variety of values. Table 1 repeats the comparison shown in FIG. 5. The data indicates that EDG and BDG are close in parameter space, while MMB is far from the target range.

[0024] [Table 1]

[0025] Solvents exhibiting these HSP values ​​can effectively strip and remove hardened photoresist. Effective stripping and removal of hardened photoresist can occur for the following reasons: Solvents with HSP values ​​near the center point of the HSP coordinate system disclosed herein may have poor compatibility with the components of hardened photoresist and may have little effect in dissolving the hardened photoresist. However, certain organic solvents can promote contact between the alkaline agent in the hardened photoresist and water, facilitating reaction between the alkaline agent and the terminal carboxyl groups of the hardened photoresist. The action of such certain organic solvents can cause a neutralization reaction between the terminal carboxyl groups of the hardened photoresist and the alkaline agent, introducing an aqueous solution between the hardened photoresist and the metal layer, causing the hardened photoresist to swell. The swollen hardened photoresist can be effectively stripped from the metal layer. In this way, certain organic solvents with characteristic HSP values ​​may be able to remove hardened photoresist more efficiently than organic solvents with different HSP values ​​that have the effect of dissolving the photoresist. This mechanism is believed to explain at least part of the effectiveness of the disclosed formulations, but other mechanisms may also contribute, alternatively or additionally.

[0026] Next, we attempted to optimize the BDG:EDG ratio depending on the HSP. The results are shown in Table 2. Here, "cleaning time" refers to the time observed to remove 46 μm of the first cured photoresist PR1 in a solvent composition maintained at 70° C. and magnetically stirred at 500 rpm.

[0027] [Table 2]

[0028] Following the preliminary tests, more detailed studies were conducted. Figure 6 illustrates an embodiment of an exemplary evaluation method applicable to the solvent compositions herein. The first stage of the evaluation method assesses the rate at which the solvent composition can clean hardened photoresist from a semiconductor surface 602, such as a wafer or die. First, a silicon (Si) substrate with a thin copper layer (a seed layer for subsequent plating) is provided. Second, a film of photoresist resin is applied to a reproducible thickness (e.g., 46 μm). Third, photolithography is performed using predefined process parameters and an optical mask with a predefined configuration. Fourth, copper (Cu) 606 is precipitated by bump plating using the pattern 604 of hardened photoresist as a barrier. Fifth, the hardened photoresist is removed using the solvent composition under investigation according to a predetermined stripping procedure. An example of a stripping procedure is detailed below.

[0029] First, a solvent composition is prepared by combining the components (e.g., magnetically stirring at 500 rpm) and heating to a target temperature of 70°C. Second, the wafer or die is placed in the stirred and heated solvent composition and left for 2 to 10 minutes. Third, the wafer or die is removed from the solvent composition, rinsed with purified (e.g., distilled) water, and dried with a stream of dry nitrogen, argon, or helium. Fourth, optical microscopy (OM) and / or scanning electron microscopy (SEM) are used to determine the effectiveness of hardened photoresist removal. Optionally, the time interval for achieving sufficient cleaning (herein "cleaning time") can be classified as "good" if the cleaning time is less than 4 minutes, "medium" if the cleaning time is 4 to 8 minutes, and "poor" if the cleaning time is greater than 8 minutes.

[0030] Next, a method for assessing compatibility with Cu-based additive structures is described. First, a Cu film of a predetermined thickness (e.g., 200 nanometers (nm)) is applied to a Si substrate using physical vapor deposition (PVD). Second, a solvent composition is prepared as described above. Third, a wafer is immersed in the stirred and heated solvent composition for 30 to 120 minutes. Fourth, the wafer is rinsed and dried as described above. Fifth, four-point probe metrology is used to measure the change in sheet resistance, the change in Cu adlayer thickness, and the etch rate as a result of immersion in the solvent composition.

[0031] Table 3 lists examples of solvent compositions for removing hardened photoresist. Experimental examples marked with italic letters are comparative examples. The components are classified as shown in Figures 1 to 4, and the amounts are shown in mass percent.

[0032] [Table 3]

[0033] The results of the study are shown in Table 4. The values ​​in the column headed "Cleaning Time" have the same meaning as above. The values ​​in the column headed "Cleaning Time" refer to additional metrics, where the first value is the time to remove 17.8 μm of the second cured photoresist PR2, the second value is the time to remove 46 μm of the third cured photoresist PR3, the third value is the time to remove 76 μm of the first cured photoresist PR1, and the fourth value is the time to remove the fourth cured photoresist PR4. The units in these columns are Angstroms / minute.

[0034] [Table 4]

[0035] Based on these results, a solvent composition can be formulated for dissolving hardened photoresist on a semiconductor surface, such as a wafer or die. The solvent composition can include about 1 to 30% by weight of at least one alkanolamine, about 10 to 95% by weight of at least one ethylene glycol ether, and 0 to about 1% by weight of an N,N-disubstituted hydroxylamine. The N,N-disubstituted hydroxylamine can be selected based on the at least one alkanolamine, and the N,N-disubstituted hydroxylamine is alkanol-substituted in any solvent composition that includes N-methyldiethanolamine. As an example of the present disclosure, the solvent composition may include, for example, 0.5% by weight or more and less than 30.5% by weight of at least one alkanolamine, 9.5% by weight or more and less than 95.5% by weight of at least one ethylene glycol ether, and 0% by weight or more and less than 1.5% by weight of an N,N-disubstituted hydroxylamine. As an example of the present disclosure, the solvent composition may include, for example, 1 to 30% by weight of at least one alkanolamine, 10 to 95% by weight of at least one ethylene glycol ether, and 0 to 1% by weight of an N,N-disubstituted hydroxylamine. The alkanolamine content is preferably, for example, 0.5% by mass or more and less than 30.5% by mass, with the lower limit being more preferably 1% by mass or more, even more preferably 5% by mass or more, still more preferably 15% by mass or more, and even more preferably 25% by mass or more. The content of ethylene glycol ether is preferably, for example, 9.5% by mass or more and less than 95.5% by mass. The lower limit may be 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, or 60% by mass or more. The upper limit may be 95% by mass or less, 90% by mass or less, or 85% by mass or less. The content of N,N-disubstituted hydroxylamine is preferably, for example, 0% by mass or more and less than 1.5% by mass. The lower limit may be greater than 0% by mass or may be 0.5% by mass or more. The upper limit may be 1% by mass or less.

[0036] In some experimental examples, the aforementioned 0 to about 1% by weight is about 1% by weight. In this case, the aforementioned 0 to about 1% by weight may be, for example, 0% by weight or more and 1.5% by weight or less. In this case, the lower limit may be, for example, greater than 0% by weight, or 0.5% by weight or more. Furthermore, the upper limit may be, for example, less than 1.5% by weight, or 1% by weight or less. In more specific experimental examples, the N,N-disubstituted hydroxylamine may include N,N-diethanolhydroxylamine, as in Experimental Example 17. In some experimental examples, the N,N-disubstituted hydroxylamine may function as a corrosion inhibitor. However, any, some, or all of the solvent compositions herein may further include an additional corrosion inhibitor. More generally, any, some, or all of the solvent compositions herein may include other compounds, including the compounds of FIG. 4.

[0037] In the present disclosure, the solvent composition may further include a corrosion inhibitor. Examples of additional corrosion inhibitors include an azole compound. The content of the azole compound is preferably 0.5% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.01% by mass or less, and most preferably 0% by mass. The solvent composition may or may not include an azole compound, and preferably does not include an azole compound.

[0038] The at least one alkanolamine in the solvent composition may comprise a primary, secondary, or tertiary amine. In some examples, the at least one alkanolamine comprises monoethanolamine, and the N,N-disubstituted hydroxylamine is alkyl-substituted. More specifically, the N,N-disubstituted hydroxylamine may comprise N,N-diethylhydroxylamine, for example, as in Example 19. In some examples, the at least one alkanolamine comprises monoethanolamine, N-methylethanolamine, and / or N-methyldiethanolamine.

[0039] In view of the above, the following aspect is a preferred example of the present disclosure. A preferred solvent composition formulated to dissolve hardened photoresist on a semiconductor surface comprises about 1-30% by weight monoethanolamine, about 10-95% by weight of a mixture of ethylene glycol ethers comprising diethylene glycol monobutyl ether (BDG) and diethylene glycol monoethyl ether (EDG), and about 1% by weight N,N-diethylhydroxylamine (DEHA). In this solvent composition, for example, the lower limit of the content of the monoethanolamine (about 1 to 30% by mass) may be 1% by mass or more, 2% by mass or more, or 3% by mass or more. Also, the upper limit of the content of the monoethanolamine (about 1 to 30% by mass) may be, for example, 20% by mass or less, 15% by mass or less, 10% by mass or less, or 7% by mass or less. Furthermore, in this solvent composition, the content of the mixture of ethylene glycol ethers (BDG and EDG) may be, for example, 10 to 95% by mass, and the lower limit of this content may be, for example, 40% by mass or more, 60% by mass or more, 80% by mass or more, or 85% by mass or more. The content of BDG in this solvent composition may be, for example, 30 to 50 mass %, and the content of EDG in the solvent composition may be, for example, 45 to 65 mass %. Furthermore, the ratio of BDG:EDG in the mixture (BDG and EDG) may be, for example, 1:1 / 3 to 1:3, 1:1 to 1:3, or 1:1 to 1:2.5. Furthermore, in this solvent composition, for example, the aforementioned approximately 1 to 30% by mass contains approximately 5% by mass, and more preferably, the aforementioned mixture contains approximately 37% by mass of BDG and approximately 56% by mass of EDG.

[0040] In view of the above, another preferred example of the present disclosure is as follows. A preferred solvent composition formulated to dissolve hardened photoresist on a semiconductor surface comprises about 1-30% by weight methyldiethanolamine, about 10-95% by weight of a mixture of ethylene glycol ethers including diethylene glycol monobutyl ether (BDG) and diethylene glycol monoethyl ether (EDG), and about 1% by weight N,N-diethanolhydroxylamine (DEHA). In this solvent composition, the lower limit of the methyldiethanolamine content (about 1 to 30% by mass) may be, for example, 1% by mass or more, 2% by mass or more, or 3% by mass or more. The upper limit of the methyldiethanolamine content (about 1 to 30% by mass) may be, for example, 20% by mass or less, 15% by mass or less, 10% by mass or less, or 7% by mass or less. Furthermore, in this solvent composition, the content of the mixture of ethylene glycol ethers (BDG and EDG) may be, for example, 10 to 95% by mass, and the lower limit of this content may be 40% by mass or more, 60% by mass or more, 80% by mass or more, or 85% by mass or more. The content of BDG in this solvent composition may be, for example, 30 to 50 mass %, and the content of EDG in this solvent composition may be, for example, 45 to 65 mass %. Furthermore, the ratio of BDG:EDG in the mixture (BDG and EDG) may be, for example, 1:1 / 3 to 1:3, 1:1 to 1:3, or 1:1 to 1:2.5. Furthermore, in this solvent composition, for example, the aforementioned approximately 1 to 30% by mass contains approximately 5% by mass, and more preferably, the aforementioned mixture contains approximately 37% by mass of BDG and approximately 56% by mass of EDG.

[0041] In view of the above, the following aspect can be mentioned as yet another preferred example of the present disclosure. A preferred solvent composition formulated to dissolve hardened photoresist on a semiconductor surface includes about 5% by weight methyldiethanolamine, about 94% by weight of a mixture of ethylene glycol ethers including diethylene glycol monobutyl ether (BDG) and diethylene glycol monoethyl ether (EDG), and about 1% by weight N,N-diethylhydroxylamine (DEHA). In this solvent composition, the content of the methyldiethanolamine (about 5% by mass) may be, for example, 4.5% by mass or more and less than 5.5% by mass. Furthermore, in this solvent composition, the content (approximately 94% by mass) of the mixture of ethylene glycol ethers (BDG and EDG) may be, for example, 93.5% by mass or more and less than 95.5% by mass. The content of BDG in this solvent composition may be, for example, 30 to 50 mass %, and the content of EDG in this solvent composition may be, for example, 45 to 65 mass %. Furthermore, the ratio of BDG:EDG in the mixture (BDG and EDG) may be, for example, 1:1 / 3 to 1:3, 1:1 to 1:3, or 1:1 to 1:2.5. Furthermore, in this solvent composition, the mixture of ethylene glycol ethers preferably contains about 40% by mass of diethylene glycol monobutyl ether (BDG) and about 60% by mass of diethylene glycol monoethyl ether (EDG).

[0042] In some experimental examples, the aforementioned 0 to about 1% by mass is 0% by mass, as in Experimental Examples 1 to 15. In some experimental examples, the at least one ethylene glycol ether may be protic. In some experimental examples, the at least one ethylene glycol ether may be an alcohol. In some experimental examples, the at least one ethylene glycol ether includes 3-methoxy-3-methylbutanol, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, and / or diethylene glycol monomethyl ether.

[0043] In some examples, the at least one alkanolamine and the at least one ethylene glycol ether are selected based on the calculated solubility of the cured photoresist in the solvent composition. Here, the solubility may be calculated according to a model of dispersion forces, dipole forces, and hydrogen bonding between the solvent system and the cured photoresist. In a variation of this approach, the only solvent modeled in this manner may be the ethylene glycol ether component. In some examples, the model is an HSP model. In some examples where an HSP model is used, the model parameters may include δD of 14-20, δP of 4-10, and δH of 7-15.

[0044] No aspect of the present disclosure should be construed in a limiting sense, as numerous variations, extensions, and omissions are likewise contemplated. For example, while the above description specifically refers to removing hardened photoresist from semiconductor wafers and dies, the solutions herein are equally applicable to semiconductor devices, panels (e.g., panel level packages), carriers, etc.

[0045] There are several alternative methods to HSP for predicting solubility based on energetics. The Hildebrand solubility parameter (δ) is a measure of the cohesive energy density of a substance. It is defined as the square root of the cohesive energy density. Regular solution theory uses the Hildebrand parameter and assumes that mixing occurs without any change in the volume or energy of the mixture. The Flory-Huggins solution theory extends regular solution theory to polymers, accounting for the size difference between solvent and polymer molecules. The Universal Quasi-Chemical Functional Group Activity Coefficient (UNIFAC) estimates activity coefficients using a group contribution method in which molecules are divided into functional groups with known interaction parameters. The Conductor-Like Screening Model of Real Solvents (COSMO-RS) is a quantum chemistry-based method that uses a dielectric continuum model to calculate the solvation free energy of molecules, including those containing hydrogen bonds. The Kamlet-Taft parameters include α (hydrogen bond donating ability), β (hydrogen bond accepting ability), and π * (polarity / polarizability). These alternative methods offer different approaches to predicting solubility and miscibility, each with strengths and limitations associated with different types of substances and mixtures.

[0046] The present disclosure is presented, by way of example, with reference to the accompanying drawings. Components, process steps, and other elements that may be substantially identical in more than one figure are coordinately identified and described with minimal repetition. It should be noted, however, that coordinately identified elements may differ to some extent. It should also be noted that the figures are schematic and generally not drawn to scale. Rather, the various drawing scales, aspect ratios, and number of elements shown in the figures may be intentionally distorted to more clearly show particular features or relationships.

[0047] It should be understood that the configurations and / or approaches described herein are exemplary in nature and subject to numerous variations, and therefore, these specific embodiments or examples should not be considered limiting. A particular routine or method described herein may represent one or more of any number of processing strategies. Accordingly, various operations illustrated and / or described may be performed in the order illustrated and / or described, in other orders, in parallel, or omitted. Similarly, the order of the above processing may be altered. In some examples, the terms "about" and "approximately," when applied to a numerical value x, extend x to include any value in the range between 0.9x and 1.1x. In some examples, these terms extend x to include any value in the range between 0.95x and 1.05x. Furthermore, each configuration and parameter disclosed herein may be combined in any combination unless otherwise specified. Furthermore, upper and lower limits of values ​​disclosed herein may be combined in any combination unless otherwise specified.

[0048] The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various processes, systems, and structures, as well as other features, functions, acts, and / or properties disclosed herein, as well as any and all equivalents thereof. [Explanation of symbols]

[0049] PR1: Hardened photoresist PR2: Hardened photoresist PR3: Hardened photoresist PR4: Hardened photoresist 602:Semiconductor surface 604: Pattern 606: Copper (Cu)

Claims

1. 1. A solvent composition formulated to dissolve hardened photoresist on a semiconductor surface, comprising: about 1 to 30% by weight of at least one alkanolamine; about 10 to 95% by weight of at least one ethylene glycol ether; and 0 to about 1 wt. % of an N,N-disubstituted hydroxylamine selected based on the at least one alkanolamine; The N,N-disubstituted hydroxylamine is alkanol-substituted in any solvent composition containing N-methyldiethanolamine. Solvent composition.

2. The 0 to about 1% by weight is about 1% by weight. The solvent composition of claim 1 .

3. The N,N-disubstituted hydroxylamine includes N,N-diethanolhydroxylamine. The solvent composition of claim 2.

4. the at least one alkanolamine comprises monoethanolamine and the N,N-disubstituted hydroxylamine is alkyl substituted; The solvent composition of claim 1 .

5. The N,N-disubstituted hydroxylamine includes N,N-diethylhydroxylamine. The solvent composition according to claim 4.

6. The 0 to about 1% by weight is 0% by weight. The solvent composition of claim 1 .

7. the at least one ethylene glycol ether is an alcohol; The solvent composition of claim 1 .

8. the at least one alkanolamine comprises monoethanolamine, N-methylethanolamine, and / or N-methyldiethanolamine; The solvent composition of claim 1 .

9. the at least one ethylene glycol ether comprises 3-methoxy-3-methylbutanol, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, and / or diethylene glycol monomethyl ether; The solvent composition of claim 1 .

10. the at least one alkanolamine and the at least one ethylene glycol ether are selected based on a calculated solubility of the hardened photoresist in the solvent composition, the solubility being calculated according to a model of dispersion forces, dipole forces, and hydrogen bonding between the solvent system and the hardened photoresist; The solvent composition of claim 1 .

11. The model is the Hansen Solubility Parameter model. The solvent composition of claim 10.

12. The parameters of the model include δD between 14 and 20, δP between 4 and 10, and δH between 7 and 15. The solvent composition of claim 11.

13. further comprising a corrosion inhibitor; The solvent composition of claim 1 .

14. 1. A solvent composition formulated to dissolve hardened photoresist on a semiconductor surface, comprising: about 1 to 30% by weight of monoethanolamine; about 10 to 95% by weight of a mixture of ethylene glycol ethers comprising diethylene glycol monobutyl ether (BDG) and diethylene glycol monoethyl ether (EDG); Approximately 1% by weight of N,N-diethylhydroxylamine (DEHA) A solvent composition comprising:

15. said about 1 to 30% by weight comprises about 5% by weight; The mixture comprises about 37% by weight of BDG and about 56% by weight of EDG. The solvent composition of claim 14.

16. 1. A solvent composition formulated to dissolve hardened photoresist on a semiconductor surface, comprising: about 1 to 30% by weight of methyldiethanolamine; about 10 to 95% by weight of a mixture of ethylene glycol ethers comprising diethylene glycol monobutyl ether (BDG) and diethylene glycol monoethyl ether (EDG); About 1% by weight of N,N-diethanolhydroxylamine A solvent composition comprising:

17. said about 1 to 30% by weight comprises about 5% by weight; The mixture comprises about 37% by weight of BDG and about 56% by weight of EDG. The solvent composition of claim 16.

18. 1. A solvent composition formulated to dissolve hardened photoresist on a semiconductor surface, comprising: About 5% by weight of methyldiethanolamine; a mixture of about 94% by weight of ethylene glycol ethers comprising diethylene glycol monobutyl ether (BDG) and diethylene glycol monoethyl ether (EDG); About 1% by weight of N,N-diethylhydroxylamine A solvent composition comprising:

19. The mixture of ethylene glycol ethers comprises about 40% by weight of diethylene glycol monobutyl ether (BDG) and about 60% by weight of diethylene glycol monoethyl ether (EDG). The solvent composition of claim 18.

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