Positone patterns from metal-organic resists

Abstract

The disclosed and claimed invention relates to the use of metal-organic resist (MOR) in positive tone processing for high-resolution patterning using chemical radiation, particularly EUV radiation at a wavelength of 13.5 nm.

Description

[Technical Field]

[0001] The disclosed and claimed invention relates to the use of metal-organic resist (MOR) in positive tone processing for high-resolution patterning using chemical radiation, particularly EUV radiation at a wavelength of 13.5 nm. [Background technology]

[0002] Metal-organic resists (MORs) have proven useful in EUV lithography due to their high absorption cross-section to EUV radiation. To date, MORs have only been documented for use in negativetone processing. While some positivetone applications have been disclosed, the unexposed material lacks adequate resistance to the developer under reasonable process conditions, leading to unacceptable film loss.

[0003] US9,310,684 (Patent Document 1) discloses a positivetone development method using dry deposition of monobutyltin oxohydrate, which reacts to form oxohydroxoclusters. The process uses an aqueous developer (which can be basic or acidic), and sharper patterns are obtained in the case of a basic solution. A TMAH solution (2.5% as a standard developer solution in semiconductor technology) has been shown to be preferable because it does not cause metal contamination from the developer.

[0004] WO22016123 (Patent Document 2) discloses the use of metal-containing complexes and reactive coreactants. Depending on the selection of the coreactant, the formed film can be developed as a positive tone (e.g., an oxalyl derivative) or a negative tone. In particular, aqueous alkaline solutions were preferred for wet development, while acid vapor was preferred for dry development. In addition, the disclosed system required additives for the clusters to crosslink the resist.

[0005] One of the consistent problems with the aforementioned positive tone development process is the extremely short development time (approximately a few seconds). Lowering the polarity of the material can increase the development time. However, the only materials used are those containing tin-oxo-hydroxoclusters; these contain hydroxyl groups, which leads to undesirably short development times.

[0006] The use of Sn6 clusters as described herein offers the advantage of being hydroxyl-free. This allows for adjustment of polarity by selecting the carboxylic acid used in synthesis. This enables significant adjustment of development time, making the development process less susceptible to fluctuations. As described herein, adjustment from relatively low-polarity to relatively high-polarity acids allows for longer development times. In addition, TMAH showed the best results in terms of development time. MOR-based positive-tone resists were demonstrated by using aqueous developers. It was also shown that the development process could be improved by adjusting the MOR to a relatively low-polarity structure. Furthermore, the use of a lower layer results in better pattern retention by taking into account the change in MOR polarity. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] US9,310,684 [Patent Document 2] WO22016123 [Patent Document 3] US10,451,974 [Non-patent literature]

[0008] [Non-Patent Document 1] M.Padmanaban et al.,Proc.SPIE Vol.8682,868215(2013),doi:10.1117 / 12.2013363 [Non-Patent Document 2] K.Yamamoto et al.,Proc.SPIE,Vol.10143,101431X(2017),DOI:10.1117 / 12.2257393 [Non-Patent Document 3] Chandrasekhar et al.,Inorg.Chem. 26,1050(1987) [Summary of the Invention]

[0009] In one aspect, the disclosed and claimed invention relates to a positive tone process for high-resolution patterning using chemically amplified radiation, and has the following formula

[0010] [Chemical Formula] [wherein, R is a C1-C6 alkyl group.] of a metal-organic compound (MOR) (hereinafter, related to the use of "(R-Sn)6O6(O2C-dithiane)". As will be apparent to those skilled in the art, the MOR is a Sn6 oxodrum type cluster having the following general structural formula:

[0011] [Chemical Formula] In one aspect of this embodiment, the chemically amplified radiation is EUV radiation with a wavelength of 13.5 nm.

[0012] This summary section does not identify all aspects and / or novel and innovative viewpoints of the disclosed and claimed invention. Instead, this summary provides only a preliminary description of various aspects and corresponding points of novelty over conventional and known techniques. For additional details and / or possible perspectives of the disclosed and claimed invention and aspects, reference should be made to the detailed description of the invention and the corresponding drawings described further below.

[0013] The order in which the different steps described herein are presented is for clarity only. In general, the steps disclosed herein can be performed in any suitable order. Additionally, although the different features, techniques, arrangements, etc., described herein may be described elsewhere in this specification, each of these concepts is intended to be implemented independently of or in combination with each other where appropriate. Therefore, the disclosed and claimed inventions can be embodied and considered in many different ways. [Brief description of the drawing] The accompanying drawings, which provide a further understanding of the disclosed invention and are incorporated into this specification and constitute part thereof, illustrate aspects of the disclosed invention and, together with the detailed description of the invention, help to illustrate the principles of the disclosed invention. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 shows the structure of (nBu-Sn)6O6(O2CCH3)6) after development. [Figure 2] Figure 2 shows the structure of (nBu-Sn)6O6(O2CH)6) after development. [Figure 3] Figure 3 shows the dose curves of the (nBu-Sn)6O6(O2CCH3)6) (dotted line) and (nBu-Sn)6O6(O2CH)6) (solid line) samples developed in the comparative example. [Figure 4] Figure 4 shows the structure of (nBu-Sn)6O6(O2C dithiane)6) after development. [Figure 5] Figure 5 shows the structure of (nBu-Sn)6O6(O2C dithiane)6) after development. [Figure 6] Figure 6 shows the dose curve of the developed (nBu-Sn)6O6(O2C dithiane)6 cluster. [Figure 7] Figure 7 shows EUV exposure of (nBu-Sn)6O6(O2C dithiane)6 (without underlying layer) on a 44nm pitch target. [Figure 8]Figure 8 shows EUV exposure of (nBu-Sn)6O6(O2C dithiane)6 (with underlying layer) on a 60nm pitch target. [Figure 9] Figure 9 shows EUV exposure of (nBu-Sn)6O6(O2C dithiane)6 (with underlying layer) on a 44nm pitch target. [Figure 10] Figure 10 shows EUV exposure of (nBu-Sn)6O6(O2C dithiane)6 (with underlayer) with a 50nm pitch target and 5 minutes of TMAH development. [Figure 11] Figure 11 shows EUV exposure of (nBu-Sn)6O6(O2C dithiane)6 (with underlying layer) with a 44nm pitch target and 2 minutes of TMAH development, followed by an additional 15 seconds of TMAH washing.

[0015] definition Unless otherwise stated, the following terms used in this specification and in the claims have the following meanings:

[0016] In this application, the use of the singular form encompasses the plural, and unless otherwise specifically stated, the singular form means "at least one." Furthermore, the use of the word "includes," and other verb forms such as "included," is not restrictive. Also, unless otherwise specifically stated, the words "element" or "component" encompass both elements or components containing one constituent unit, and elements or components containing more than one constituent unit. Unless otherwise indicated, the conjunction "and" used herein is intended to be compatible, and the conjunction "or" is not intended to be exclusive. For example, the phrase "or instead" is intended to be exclusive. The words "and / or" used herein refer to any combination of the aforementioned elements, including the use of a single element.

[0017] When used in relation to measurable variable values, the terms "approximately" or "about" refer to the stated value of the variable and all values ​​of the variable within the experimental error of the stated value (e.g., within the 95% confidence interval of the mean) or within a percentage of the stated value (e.g., ±10%, ±5%), whichever is greater.

[0018] "Chemical radiation" encompasses all forms of radiation with energy that can cause chemical changes in a photoresist composition. However, such chemical changes do not include changes caused purely by thermal effects. Examples of chemical radiation include, but are not limited to, photons with wavelengths of 13.5 nm, 193 nm, 248 nm, or 365 nm, or electron beams, or other particle beams, such as, but are not limited to, helium ion beams.

[0019] When used here, "C x-y (where x and y are integers) indicates the number of carbon atoms in the chain. For example, C 1-6 Alkyl refers to alkyl chains having a chain numbering between 1 and 6 carbon atoms (e.g., methyl, ethyl, propyl, butyl, pentyl, and hexyl). Unless otherwise specified, the above chains may be linear or branched.

[0020] Unless otherwise specified, “alkyl” refers to a hydrocarbon group that can be linear, branched (e.g., methyl, ethyl, propyl, isopropyl, tert-butyl, and analogues), cyclic (e.g., cyclohexyl, cyclopropyl, cyclopentyl, and analogues), or polycyclic (e.g., norbornyl, adamantyl, and analogues). Suitable acyclic groups may be methyl, ethyl, n- or iso-propyl, n-, iso- or tert-butyl, linear or branched pentyl, hexyl, heptyl, octyl, decyl, dodecyl, tetradecyl, and hexadecyl. Unless otherwise specified, alkyl refers to a portion of 1 to 10 carbon atoms. Cyclic alkyl groups may be monocyclic or polycyclic. Examples of monocyclic alkyl groups include substituted cyclopentyl, cyclohexyl, and cycloheptyl groups. Substituents may be any of the acyclic alkyl groups listed herein. Suitable bicyclic alkyl groups include substituted bicyclo[2.2.1]heptane, bicyclo[2.2.2]octane, bicyclo[3.2.1]octane, bicyclo[3.2.2]nonane, and bicyclo[3.3.2]decane, and analogues. Examples of tricyclic alkyl groups include tricyclo[5.4.0.0]. 2,9 ]Undecane, Tricyclo[4.2.1.2. 7,9 Undecane, Tricyclo[5.3.2.0. 4,9 ] Dodecane and tricyclo[5.2.1.0. 2,6 Examples include decane. As described herein, the cyclic alkyl group may have any of the aforementioned acyclic alkyl groups as substituents. These alkyl portions may be substituted or unsubstituted.

[0021] "Alkyl halide" refers to the linear, cyclic, or branched saturated alkyl groups defined above, in which one or more of the hydrogen atoms are replaced by halogens (e.g., F, Cl, Br, and I). Therefore, for example, fluorinated alkyl groups (also known as "fluoroalkyl groups") refer to the linear, cyclic, or branched saturated alkyl groups defined above, in which one or more of the hydrogen atoms are replaced by fluorine (e.g., trifluoromethyl, perfluoroethyl, 2,2,2-trifluoroethyl, perfluoroisopropyl, perfluorocyclohexyl, and analogues). Such haloalkyl moieties (e.g., fluoroalkyl moieties) may be unsubstituted or further substituted, unless they are perhalogenated / multihalogenated.

[0022] "Alkoxy" (also known as "alkyloxy") refers to the previously defined alkyl group bonded via the oxy (-O-) moiety (e.g., methoxy, ethoxy, propoxy, butoxy, 1,2-isopropoxy, cyclopentyloxy, cyclohexyloxy, and similar compounds). These alkoxy moieties may or may not be substituted.

[0023] "Alkylcarbonyl" refers to the previously defined alkyl group bonded via a carbonyl group (-C(=O)-)) moiety (e.g., methylcarbonyl, ethylcarbonyl, propylcarbonyl, butylcarbonyl, cyclopentylcarbonyl, and analogues). These alkylcarbonyl moieties may or may not be substituted.

[0024] "Halo" or "halide" refers to halogens (e.g., F, Cl, Br, and I).

[0025] "Hydroxy" (also known as "hydroxyl") refers to the -OH group.

[0026] Unless otherwise specified, the term "substituted" refers to any part of alkyl, alkoxy, fluorinated alkyl and analogues, and is not limited to, but includes one or more substituents, including alkyl, substituted alkyl, unsubstituted aryl, substituted aryl, alkyloxy, alkylaryl, haloalkyl, halide, hydroxy, amino, and aminoalkyl. Similarly, the term "unsubstituted" refers to any part of the same molecule that does not contain substituents other than hydrogen.

[0027] Aryl groups contain 6 to 24 carbon atoms and include phenyl, tolyl, xylyl, naphthyl, anthrasyl, biphenyls, bis-phenyls, tris-phenyls, and analogues. These aryl groups may be further substituted with any of the suitable substituents mentioned above, such as alkyl, alkoxy, acyl, or aryl groups. Similarly, suitable polyvalent aryl groups may be used in the present invention as needed. Typical examples of divalent aryl groups, i.e., arylenes, include phenylenes, xylylenes, naphthylenes, biphenylenes, and analogues. As used herein, and unless otherwise specified, the term "aromatic" refers to unsaturated cyclic hydrocarbons having a delocalized conjugated pi system and having 4 to 20 carbon atoms (aromatic C4-C 20Hydrocarbons). Exemplary aromatics include, but are not limited to, benzene, toluene, xylenes, mesitylene, ethylbenzenes, cumene, naphthalene, methylnaphthalene, dimethylnaphthalenes, ethylnaphthalenes, acenaphthalene, anthracene, phenanthrene, tetrafene, naphthacene, benzanthracene, fluoranthrene, pyrene, chrysene, triphenylene, and their analogues, and combinations thereof. The aromatics may optionally be substituted with, for example, one or more alkyl groups, alkoxy groups, halogens, etc. For example, the aromatics may include anisole. In addition, the aromatics may contain one or more heteroatoms. Examples of heteroatoms include, but are not limited to, nitrogen, oxygen, phosphorus, boron, and / or sulfur. Aromatics having one or more heteroatoms include, but are not limited to, furan, benzofuran, thiophene, benzothiophene, oxazole, thiazole, and their analogues, and combinations thereof. The aromatics may include monocyclic, bicyclic, tricyclic, and / or polycyclic rings (in some embodiments, at least monocyclic rings, monocyclic and bicyclic rings only, or monocyclic rings only), and may also be fused rings.

[0028] The term "non-aromatic" means four or more carbon atoms bonded in at least one ring structure, wherein at least one of these four or more carbon atoms in the ring structure is not an aromatic carbon atom.

[0029] The chapter titles used herein are for the purpose of organizing the document and should not be interpreted as limiting the inventions described. While not limiting, all documents or parts of documents cited herein, including patents, patent applications, articles, books, and professional texts, are considered to have their entire contents included herein for all purposes. In the event of any conflict between the definition of a term in any of the documents cited herein or similar materials and those in this specification, the definition in this specification shall prevail.

[0030] All documents, literature sources, patents, patent applications, etc., mentioned herein are to be considered as having been published in their entirety.

[0031] When referring to the composition of the chemically amplified MOR described herein in terms of weight percent (or wt%), it is understood that in all cases the total weight percent of all components, including non-essential components such as impurities, does not exceed 100% by weight. In compositions "essentially consisting of" the components described herein, such components may total 100% by weight of the composition or less than 100% by weight. If the components total less than 100% by weight, such compositions may contain small amounts of non-essential contaminants or impurities. For example, in one such embodiment, the preparation may contain 2% by weight or less of impurities. In another embodiment, the preparation may contain 1% by weight or less of impurities. In yet another embodiment, the preparation may contain 0.05% by weight or less of impurities. In other such embodiments, the components may constitute at least 90% by weight, more preferably at least 95% by weight, more preferably at least 99% by weight, more preferably at least 99.5% by weight, and most preferably at least 99.9% by weight, and may include other components that do not substantially affect the performance of the wet etching agent. In other cases, if non-essential impurity components are not significantly present, the composition of all essential components is understood to essentially total 100% by weight. [Modes for carrying out the invention]

[0032] The general description above and the detailed description below are for illustrative and explanatory purposes only and should be understood not to limit the invention described in the claims. The problem, features, advantages and ideas of the disclosed invention will be apparent to those skilled in the art from the description herein, and furthermore, the disclosed invention can be readily implemented by those skilled in the art based on the description herein. The descriptions of “preferred embodiments” and / or examples indicating preferred forms for carrying out the disclosed invention are included for explanatory purposes only and are not intended to limit the claims.

[0033] It will also be apparent to those skilled in the art that various improvements can be made to the methods of carrying out the disclosed inventions based on the views described herein, without departing from the spirit and scope of the inventions disclosed herein.

[0034] In one aspect, the disclosed and claimed invention relates to positive tone processing in high-resolution patterning using chemical radiation, with the following formula:

[0035] [ka] [In the formula, R is a C1-C6 alkyl group.] This relates to the use of metal-organic resists (MORs) (hereinafter referred to as "(R-Sn)6O6(O2C-Dithiane)6"). In one aspect of this embodiment, R is a methyl group. In one aspect of this embodiment, R is an ethyl group. In one aspect of this embodiment, R is a propyl group. In one aspect of this embodiment, R is a butyl group. In one aspect of this embodiment, R is a pentyl group. In one aspect of this embodiment, R is a hexyl group. In one preferred embodiment, R is an n-butyl group, and the cluster has the following formula:

[0036] [ka] (below,"( n Bu-Sn)6O6(O2C-Dithiane)6") has the following structural formula.

[0037] [ka] As previously described, the Sn6 cluster contains six (6) tin atoms, which have three oxobridges to other tin atoms, an organic group (often an alkyl chain) directly bonded to the tin, and two carboxylic acids bonded via one of the oxygen atoms of the acid. The acid can be broadly varied and may contain not only hydrogen (in the case of formic acid) but also an alkyl chain, a phenyl group, or an organic group having a heteroatom. These clusters are also known as drum clusters.

[0038] In one other aspect, the disclosed and claimed invention relates to the use of the MOR for positive tone processing in high-resolution patterning using chemical radiation, wherein the method of using the MOR is as follows: (i) The step of spin-coating a composition comprising the previously described MOR (for example, the previously described composition) and at least one spin-coatable solvent onto a substrate, and (ii) Exposing the spin-coated composition to chemical radiation, It may contain, essentially consist of, or consist of. Suitable substrates include silicon, aluminum, polymer resins, silicon dioxide, doped silicon dioxide, silicon nitride, tantalum, copper, polysilicon, ceramics, aluminum / copper mixtures; gallium arsenide and other such III / V compounds. The photoresist may be coated onto an anti-reflective film or other underlayer (e.g., an underlayer specifically designed for EUV photoresist, but not limited to) or onto a hard mask, for example, a hard mask used for pattern transfer in a three-layer process. In one aspect of this embodiment, the chemical radiation is EUV radiation with a wavelength of 13.5 nm. In one aspect of this embodiment, the chemical radiation is either electron radiation or soft X-ray radiation.

[0039] In one aspect of this embodiment, the at least one spin-coatable solvent of step (i) comprises, essentially consists of, or comprises one or more solvents suitable for spin coating. Examples of such solvents include, but are not limited to, glycol ether derivatives, e.g., ethyl cellosolve, methyl cellosolve, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol dimethyl ether, propylene glycol n-propyl ether, or diethylene glycol dimethyl ether; glycol ether ester derivatives, e.g., ethyl cellosolve acetate, methyl cellosolve acetate, or propylene glycol monomethyl ether acetate; carboxylates, e.g., ethyl acetate, n-butyl acetate, and amyl acetate; carboxylates of dibasic acids, e.g., diethyl oxylate and dimethyl malonate; dicarboxylates of glycols, e.g., ethylene glycol diacetate and propylene glycol diacetate; and hydroxycarboxylates, e.g., methyl lactate, ethyl lactate, ethyl glycolate, and ethyl 3-hydroxypropionate; ketone esters, e.g., methyl pyruvate or ethyl pyruvate; Examples include alkoxycarboxylic acid esters, such as methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 2-hydroxy-2-methylpropionate, or methyl ethoxypropionate; ketone derivatives, such as methyl ethyl ketone, acetylacetone, cyclopentanone, cyclohexanone, or 2-heptanone; ketone ether derivatives, such as methyl diacetone alcohol ether; ketone alcohol derivatives, such as acetol or diacetone alcohol; lactones, such as butyrolactone; and amide derivatives, such as dimethylacetamide or dimethylformamide, anisole, and mixtures thereof.In one embodiment, preferred solvents include propylene glycol monoalkyl ether, propylene glycol alkyl (e.g., methyl) ether acetate, ethyl-3-ethoxypropionate, toluene, xylene, diglyme, amyl acetate, ethyl lactate, butyl acetate, 2-heptanone, ethylene glycol monoethyl ether acetate, and mixtures thereof. In another embodiment, preferred solvents include, but are not limited to, anisole, 4-methyl-2-pentanol, cyclohexanone, toluene, propylene glycol monomethyl ether, and 2-heptanone. In yet another embodiment, the composition contains more than one solvent.

[0040] From yet another perspective, the composition comprising the aforementioned MOR and at least one spin-coatable solvent has a solvent content ranging from about 49% to about 99% of the total weight of the composition.

[0041] In another aspect of this embodiment, the method further optionally comprises, or essentially comprises, a step of performing a post-application bake ("PEB") heat treatment of the substrate having the spin-coated composition before the exposure (i.e., before step (ii)). The purpose of this step is to dry the spin-coated photoresist layer (i.e., remove any residual solvents) before the exposure. This PAB step is also alternatively called a pre-bake or soft bake. PAB is usually performed on a hot plate or in an oven. For hot plate PAB, preferred temperatures are from about 80°C to about 150°C, more preferably from about 90°C to about 130°C, and most preferably from about 90°C to about 120°C. For hot plate PAB, preferred times are from about 45 seconds to about 180 seconds, more preferably from about 45 seconds to about 120 seconds, and most preferably from about 60 seconds to about 120 seconds. Oven PAB may use different times and temperatures depending on the type of oven and contact method.

[0042] In one other aspect of this embodiment, the method further optionally includes, or essentially comprises, a step of performing a post-exposure bake ("PEB"). In yet another aspect, the PEB is performed at a temperature higher than the ambient temperature. In yet another aspect, the PEB is performed at a temperature between about 80°C and about 200°C. In yet another aspect, the PEB is performed at a temperature between about 90°C and about 170°C. In yet another aspect, the PEB is performed at a temperature between about 120°C and about 150°C. In yet another aspect, the PEB is performed at a temperature between about 150°C and about 180°C. In yet another aspect, the PEB is performed at a temperature of about 80°C. In yet another aspect, the PEB is performed at a temperature of about 85°C. In yet another aspect, the PEB is performed at a temperature of about 90°C. In yet another aspect, the PEB is performed at a temperature of about 100°C. In yet another aspect, the PEB is performed at a temperature of about 110°C. From yet another perspective, PEB is performed at a temperature of approximately 120°C. From yet another perspective, PEB is performed at a temperature of approximately 130°C. From yet another perspective, PEB is performed at a temperature of approximately 140°C. From yet another perspective, PEB is performed at a temperature of approximately 150°C. From yet another perspective, PEB is performed at a temperature of approximately 160°C. From yet another perspective, PEB is performed at a temperature of approximately 170°C. From yet another perspective, PEB is performed at a temperature of approximately 180°C. From yet another perspective, PEB is performed at a temperature of approximately 190°C. From yet another perspective, PEB is performed at a temperature of approximately 200°C. From yet another perspective, PEB is performed for approximately 30 to 300 seconds. From yet another perspective, PEB is performed for approximately 50 to 180 seconds. From yet another perspective, PEB is performed for approximately 60 to 120 seconds.

[0043] In one other aspect of this embodiment, the method further optionally comprises or comprises the step of developing a substrate in a solvent. In yet another aspect, the development of the substrate is carried out for about 30 seconds to about 300 seconds. In yet another aspect, the solvent developer may be a polar solvent, such as a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, and an ether solvent, and a hydrocarbon solvent may also be used. Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, isobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, actonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, and propylene carbonate. Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, and propyl lactate.Examples of alcohol-based solvents include alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, and n-decanol; glycol-based solvents such as ethylene glycol, diethylene glycol, and triethylene glycol; and glycol ether-based solvents such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and methoxymethylbutanol. Examples of ether-based solvents include the glycol ether-based solvents mentioned above, dioxane, and tetrahydrofuran. Examples of amide-based solvents include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphate triamide, and 1,3-dimethyl-2-imidazolidinone. Examples of hydrocarbon solvents include aromatic hydrocarbon solvents, such as toluene and xylene, and aliphatic hydrocarbon solvents, such as pentane, hexane, heptane, octane, nonane, and decane, or petroleum distillates of the type commonly known as white spirits. Multiple of these solvents may be mixed, or the solvents may be mixed with other solvents or water.

[0044] In another aspect of this embodiment, the method further optionally includes, or essentially comprises, a step of performing a solvent cleaning. Suitable solvents for cleaning include, but are not limited to, one or more hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. More preferably, a step of cleaning the resist film is performed after negativetone development using a cleaning solution containing at least one organic solvent selected from ketone solvents, ester solvents, alcohol solvents, and amide solvents; even more preferably, a step of cleaning the resist film is performed after development using a cleaning solution containing an alcohol solvent or an ester solvent; and even more preferably, a step of cleaning the resist film is performed after development using a cleaning solution containing a monohydric alcohol. Monohydric alcohols used in the cleaning step after negativetone development include linear, branched, or cyclic monohydric alcohols, and specific examples of monohydric alcohols that can be used include 1-butanol, 2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, 1-pentanol, and 2-pentanol. 1-Hexanol, 1-Heptanol, 1-Octanol, 2-Hexanol, 2-Heptanol, 2-Octanol, 3-Hexanol, 3-Heptanal, 3-Octanol, and 4-Octanol are preferred. In one other aspect, the solvent cleaning comprises more than one solvent.

[0045] In one other aspect of this embodiment, the method further optionally comprises or comprises the step of developing a substrate in an aqueous basic developer. In yet another aspect, the development of the substrate is carried out for about 30 to about 300 seconds. In one embodiment, the developer is a buffered or unbuffered solution of NaOH or KOH. In one embodiment, the aqueous developer is a metal ion-free (MIF) developer. Examples of such MIF developers include, but are not limited to, tetramethylammonium hydroxide (TMAH), tetra-n-butylammonium hydroxide (TBAH), tetraethylammonium hydroxide (TEAH), or choline hydroxide at concentrations from 0.05 to 3N, preferably from 0.1 to 3N, and most preferably from 2.3 to 2.7N. One preferred developer is TMAH.

[0046] In one aspect of this embodiment, after the developing step, washing is performed using an aqueous washing solution. This washing solution may contain a surfactant that lowers its surface tension to that of water. Such a solution is used to minimize pattern collapse due to capillary forces. Theoretical predictions of such pattern collapse are directly proportional to the surface tension. These may further contain other additives that reduce pattern collapse and help maintain the pattern shape of the resist structure during washing. Such solutions are described, for example, in M. Padmanaban et al., Proc. SPIE Vol. 8682, 868215 (2013), doi: 10.1117 / 12.2013363 (Non-Patent Literature 1); K. Yamamoto et al., Proc. SPIE, Vol. 10143, 101431X (2017), DOI: 10.1117 / 12.2257393 (Non-Patent Literature 2); and US10, 451, 974 (Patent Literature 3).

[0047] In another aspect of this embodiment, the method further optionally includes, or essentially comprises, a (vii) heat treatment step (i.e., hard bake) after developing and washing. This hard bake step can be carried out on a hot plate or in an oven, or optionally using microwave or infrared irradiation, including a high-temperature short-time annealing (RTA) system or a laser irradiation system. If the hard bake is carried out on a hot plate, the preferred temperature is from about 110°C to about 300°C, more preferably from about 130°C to about 220°C. The preferred hard bake time on the hot plate is from about 30 seconds to about 300 seconds, more preferably from about 50 seconds to about 120 seconds. Hard bake times in an oven are typically longer than in the case of a hot plate to compensate for the relatively less efficient heat transfer. Hard baking may be carried out under standard atmospheric conditions, with moisture removed, with increased moisture, in an oxygen-enriched atmosphere or in pure oxygen, or in an inert gas (including nitrogen or argon, but not limited to) under oxygen-excluded conditions. [Examples]

[0048] The following describes more specific aspects of this disclosure and experimental results supporting such aspects. These examples are provided below to better illustrate the disclosed invention and should not be interpreted as limiting the disclosed invention in any way.

[0049] It will be apparent to those skilled in the art that various improvements and modifications can be made to the disclosed invention and the specific examples provided herein without departing from the spirit or scope of the disclosed invention. Therefore, the disclosed invention, including the descriptions provided by the following examples, is intended to encompass improvements and modifications of the disclosed invention that fall within the scope of any claim and its equivalents.

[0050] Materials and methods: The disclosed and claimed methods utilize commercially available materials (e.g., THF, PGME, cyclohexanone, toluene, formic acid, acetic acid, 1,3-dithiane-2-carboxylic acid (CAS 20461-89-6), CDCl3, C6D6). All cluster materials were prepared according to the improved literature procedures. See Chandrasekhar et al., Inorg. Chem, 26, 1050 (1987) (Non-Patent Document 3).

[0051] Comparative Example Sn6 formyl clusters (i.e., n (Bu-Sn)6O6(O2CH)6) and Sn6 acetate clusters (i.e., n (Bu-Sn)6O6(O2CCH3)6) resists were each prepared at 20 g / l in cyclohexane (formyl cluster) and 10 g / l in toluene (acetate cluster). These formulations were spin-coated onto Si wafers treated with oxygen plasma (400 W, 10 minutes). After soft baking at 100 °C for 2 minutes, one set of wafers was diced into multiple pieces, and the time to completely remove the film was determined for both coatings using a TMAH-based developer AZ726MIF. For the formyl cluster, that time was 25 seconds, and for the acetate cluster, it was 60 seconds.

[0052] Another set of coated wafers was exposed to an electron beam (30 kV) at dose levels from 10 to 5000 μC / cm 2 up to. After exposure, a post-exposure bake was performed at 120 °C for 2 minutes. Then, both wafers were developed using a TMAH solution AZ726MIF for 13 seconds for the formyl cluster and 3 seconds for the acetate cluster. Thereafter, these wafers were washed with water and dried under nitrogen.

[0053] Figure 1 shows the pattern of the Sn6 acetate cluster after development with TMAH. Figure shows the pattern of the Sn6 formyl cluster after development with TMAH. Figure 3 shows the developed Sn6 formyl cluster nBu-Sn)6O6(O2CH)6) and Sn6 acetate cluster ( n The dose curve for Bu-Sn)6O6(O2CCH3)6) is shown.

[0054] As seen in Figures 1-3, very clear patterns can be observed for both clusters. After TMAH development, the surface of the acetate cluster is rougher than that of the formyl cluster, but film loss is less than that of the formyl cluster. The dose curve in Figure 3 shows better contrast for the acetate cluster. This was already expected from the very short development time of the formyl cluster. Due to the lower contrast of the formyl cluster, this shows a faster photospeed but with 50% film loss.

[0055] Example 1 ( in toluene) n A 10 g / l resist formulation of Bu-Sn)6O6(O2C-Dithiane)6 was prepared, applied at a spin speed of 3500 rpm, and dried at 100°C for 120 seconds. One coating showed no film loss when exposed to TMAH (2.36 wt%) for 300 seconds. The other coating was exposed to 10 to 5000 μC / cm using an accelerating voltage of 30 kV. 2 The samples were exposed to an electron beam at the specified dose levels. After a post-exposure bake at 120°C for 120 seconds, these coatings were developed with TMAH for 60 seconds and then washed in water.

[0056] Figures 4 and 5 show the results after treatment with TMAH for 60 seconds. n The developed structure of Bu-Sn)6O6(O2C-Dithiane)6 is shown. Figure 6 shows the developed ( n The dose curve for Bu-Sn)6O6(O2C dithiane)6 cluster is shown. The dose curve in Figure 6 is ( n Bu-Sn)6O6(O2C dithiane)6 exhibits better sensitivity and contrast compared to the formic acid and acetic acid clusters in the comparative example.

[0057] Following the results described above, EUV exposure was performed at the Paul Schärer Institute in Villigen, Switzerland. ( n A 25 nm film was obtained by spin-coating a 10 g / l resist of Bu-Sn)6O6(O2C-Dithiane)6. PAB at 100°C and PEB at 120°C were used. After PEB, development times of 120 to 300 seconds were used. The first patterning, performed on bare silicon wafers with various pitches from 100 nm to 44 nm, was targeted using 120 seconds of TMAH (2.38 wt%) development. As seen in Figure 7, severe pattern collapse was observed. The use of an underlayer (Merck AZExpO60110) significantly improved the results with the same formulation and processing conditions. Figure 8 shows the results for a 60 nm pitch when using the AZExpO6010 underlayer. n This shows the EUV patterning of the Bu-Sn)6O6(O2C-Dithiane)6 cluster. 67 mJ / cm² 2 A clear pattern is observed after development with TMAH (2.38 wt%) for 120 seconds. Figure 9 shows the case of a 44 nm pitch when using the lower layer AZExpO6010. n This shows the EUV patterning of the Bu-Sn)6O6(O2C-Dithiane)6 cluster. 62 mJ / cm² 2 A clear pattern is observed after development with TMAH (2.38 wt%) for 120 seconds.

[0058] Undisclosed ( n Bu-Sn)6O6(O2C-Dithiane)6 clusters exhibit resistance to TMAH (2.38 wt%) for more than 300 seconds. The same formulation, i.e., in toluene, n A 10 g / l resist of Bu-Sn)6O6(O2C-dithiane)6 was used on AZExpO6010, but with a longer development time of 300 seconds. Figure 10 shows the results for a 50 nm pitch when using AZExpO6010 as the lower layer. n This shows the EUV patterning of the Bu-Sn)6O6(O2C-Dithiane)6 cluster. 49 mJ / cm² 2 And it shows a good pattern. Figure 11 shows the same ( nThe Bu-Sn)6O6(O2C-Dithiane)6 formulation is illustrated, including a 20-second TMAH (2.38%) wash after the initial 120-second development. Figure 11 shows the case of a 44 nm pitch when using the underlayer AZExpO6010. n This shows the EUV patterning of the Bu-Sn)6O6(O2C-Dithiane)6 cluster. 53 mJ / cm² 2 In this case, a clear pattern was observed, and the amount of scum was reduced compared to when washing or a longer development time of 300 seconds was not used.

[0059] While the disclosed and claimed inventions have been described and explained with a certain degree of detail, it should be understood that this disclosure is merely illustrative, and that a person skilled in the art may rely on numerous variations in the conditions and order of each step without departing from the spirit and scope of the disclosed and claimed inventions.

Claims

1. A method for positive tone processing, and the next steps: (i) the following (a) and (b) (a) Metal-organic resist (MOR) of the following formula, 【Chemistry 1】 [In the formula, R is C １ -C ６ It is an alkyl group. (b) at least one spin-coatable solvent, The steps of spin-coating a composition containing onto a substrate; and (ii) Exposing the spin-coated composition to chemical radiation, Methods that include...

2. The method according to claim 1, wherein R is a methyl group.

3. The method according to claim 1, wherein R is an ethyl group.

4. The method according to claim 1, wherein R is a propyl group.

5. The method according to claim 1, wherein R is a butyl group.

6. The method according to claim 1, wherein R is a pentyl group.

7. The method according to claim 1, wherein R is a hexyl group.

8. The method according to claim 1, wherein the substrate of step (i) comprises one or more of silicon, aluminum, polymer resin, silicon dioxide, doped silicon dioxide, silicon nitride, tantalum, copper, polysilicon, ceramic, aluminum / copper mixture; gallium arsenide and other such Group III / V compounds.

9. The method according to claim 1, wherein the composition of step (i) is coated on one or more of the anti-reflective coating, underlayer, and hard mask.

10. The method according to claim 1, wherein at least one spin-coatable solvent in step (i) comprises at least one of glycol ether derivatives, glycol ether ester derivatives, carboxylates, carboxylates of dibasic acids, dicarboxylates of glycols, hydroxycarboxylates, ketone esters, alkoxycarboxylic acid esters, ketone derivatives, ketone ether derivatives, ketone alcohol derivatives, lactones, amide derivatives, anisoles, and mixtures thereof.

11. The method according to claim 1, wherein at least one spin-coatable solvent in step (i) comprises at least one of propylene glycol monoalkyl ether, propylene glycol alkyl (e.g., methyl) ether acetate, ethyl-3-ethoxypropionate, toluene, xylene, diglym, amyl acetate, ethyl lactate, butyl acetate, 2-heptanone, ethylene glycol monoethyl ether acetate, and mixtures thereof.

12. The method according to claim 1, wherein at least one spin-coatable solvent in step (i) comprises at least one of anisole, 4-methyl-2-pentanol, cyclohexanone, toluene, propylene glycol monomethyl ether, and 2-heptanone.

13. The method according to claim 1, wherein at least one spin-coatable solvent in step (i) comprises more than one solvent.

14. The method according to claim 1, wherein the metal-organic resist and at least one solvent in step (i) constitute about 49% to about 99% by weight of the composition.

15. The method according to claim 1, wherein the chemical radiation is EUV radiation with a wavelength of 13.5 nm.

16. The method according to claim 1, wherein the chemical radiation is one of electron radiation and soft X-ray radiation.

17. The method according to claim 1, further comprising step (i-2) of performing a post-apply bake ("PAB") heat treatment on the substrate having the spin-coated composition prior to step (ii).

18. The method according to claim 1, further comprising step (iii) of performing a post-exposure bake ("PEB") heat treatment on the substrate having the spin-coated composition, following step (ii).

19. The method according to claim 18, wherein the PEB is performed at a temperature exceeding the ambient temperature.

20. The method according to claim 18, wherein the PEB is performed at a temperature between approximately 80°C and approximately 200°C.

21. The method according to claim 18, wherein the PEB is performed at a temperature between approximately 90°C and approximately 170°C.

22. The method according to claim 18, wherein the PEB is performed at a temperature between approximately 120°C and approximately 150°C.

23. The method according to claim 18, wherein the PEB is performed at a temperature between approximately 150°C and approximately 180°C.

24. The method according to claim 18, wherein the PEB is performed at a temperature of approximately 80°C.

25. The method according to claim 18, wherein the PEB is performed at a temperature of approximately 85°C.

26. The method according to claim 18, wherein the PEB is performed at a temperature of approximately 90°C.

27. The method according to claim 18, wherein the PEB is performed at a temperature of about 100°C.

28. The method according to claim 18, wherein the PEB is performed at a temperature of approximately 110°C.

29. The method according to claim 18, wherein the PEB is performed at a temperature of approximately 120°C.

30. The method according to claim 18, wherein the PEB is performed at a temperature of approximately 130°C.

31. The method according to claim 18, wherein the PEB is performed at a temperature of approximately 140°C.

32. The method according to claim 18, wherein the PEB is performed at a temperature of about 150°C.

33. The method according to claim 18, wherein the PEB is performed at a temperature of approximately 160°C.

34. The method according to claim 18, wherein the PEB is performed at a temperature of approximately 170°C.

35. The method according to claim 18, wherein the PEB is performed for approximately 30 seconds to approximately 300 seconds.

36. The method according to claim 18, wherein the PEB is performed for about 50 seconds to about 180 seconds.

37. The method according to claim 18, wherein the PEB is performed for about 60 seconds to about 120 seconds.

38. The method according to claim 1, further comprising the step (iv) of developing a substrate in a solvent.

39. The method according to claim 38, wherein the development of the substrate in a solvent developer is performed for about 30 seconds to about 300 seconds.

40. The method according to claim 38, wherein the solvent developer comprises one or more polar solvents.

41. The method according to claim 38, wherein the solvent developer comprises one or more of the following: ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, hydrocarbon solvents, and combinations thereof.

42. The method according to claim 38, wherein the solvent developer comprises one or more of the following: acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, actonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, and combinations thereof.

43. The method according to claim 38, wherein the solvent developer comprises one or more of the following: methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, and combinations thereof.

44. The method according to claim 38, wherein the solvent developer comprises one or more of the following: methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-decanol, ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethyl butanol, and combinations thereof.

45. The method according to claim 38, wherein the solvent developer comprises one or more of dioxane, tetrahydrofuran, and combinations thereof.

46. The method according to claim 38, wherein the solvent developer comprises one or more of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphate triamide, 1,3-dimethyl-2-imidazolidinone, and combinations thereof.

47. The method according to claim 38, wherein the solvent developer comprises one or more of toluene, xylene, pentane, hexane, heptane, octane, nonane, decane, white spirits, and combinations thereof.

48. (v) The method according to claim 1, further comprising the step of solvent cleaning.

49. The method according to claim 48, wherein the solvent cleaning in step (v) includes one or more of the hydrocarbon solvent, ketone solvent, ester solvent, alcohol solvent, amide solvent, ether solvent, and combinations thereof.

50. The method according to claim 48, wherein the solvent washing in step (v) comprises one or more of 1-butanol, 2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanal, 3-octanol, 4-octanol, and combinations thereof.

51. (vi) The method according to claim 1, further comprising the step of developing a substrate in an aqueous base developer.

52. The method according to claim 51, wherein the aqueous base developer of step (vi) comprises one or more alkaline developers.

53. The method according to claim 51, wherein the aqueous base developer of step (vi) comprises one or more of NaOH or KOH.

54. The method according to claim 51, wherein the aqueous base developer of step (vi) comprises one or more metal ion-free (MIF) developers.

55. The method according to claim 51, wherein the aqueous developer of step (vi) comprises one or more of tetramethylammonium hydroxide (TMAH), tetra-n-butylammonium hydroxide, and choline hydroxide.

56. The method according to claim 51, wherein the aqueous base developer of step (vi) comprises tetramethylammonium hydroxide (TMAH).

57. The method according to claim 1, further comprising step (vi) of performing a heat treatment step after step (vi).

58. The method according to claim 57, wherein the heat treatment is performed at a temperature between approximately 110°C and approximately 300°C.

59. The method according to claim 57, wherein the heat treatment is performed at a temperature of approximately 130°C to approximately 220°C.

60. The method according to claim 57, wherein the heat treatment is performed for approximately 30 seconds to approximately 300 seconds.

61. The method according to claim 57, wherein the heat treatment is performed for about 50 seconds to about 120 seconds.

62. The method according to claim 57, wherein the heat treatment is performed under one or more of the following conditions: under atmospheric conditions, under the exclusion of moisture, under increased humidity, in an oxygen-enriched atmosphere, in pure oxygen, or under the exclusion of oxygen in an inert gas.

63. For positive tone processing in high-resolution patterning using chemical radiation, the following equation 【Chemistry 2】 [In the formula, R is C １ -C ６ It is an alkyl group. The use of metal-organic resists (MOR).

64. The use according to claim 63, wherein R is a methyl group.

65. The use according to claim 63, wherein R is an ethyl group.

66. The use according to claim 63, wherein R is a propyl group.

67. The use according to claim 63, wherein R is a butyl group.

68. The use according to claim 63, wherein R is a pentyl group.

69. The use according to claim 63, wherein R is a hexyl group.

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