Lower layer for EUV lithography

Abstract

To provide a novel lithography composition to be used as an EUV silicon hard mask layer.SOLUTION: Provided are a method for manufacturing a microelectronic structure, and a structure as a result formed by using an EUV lithography process by the method. The method includes using a silicon hard mask layer directly under a photoresist layer. The silicon hard mask layer can be directly applied onto a substrate or onto any intermediate layer that may be applied to the substrate. A preferable silicon hard mask layer is formed of a spin-coatable polymer composition. A method according to the present invention increases adhesiveness and reduces or eliminates a pattern collapse problem.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] Related Applications This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 889,964, entitled "Underlayer for EUV Lithography," filed August 21, 2019, the entire disclosure of which is incorporated by reference.

[0002] The present invention relates generally to methods for fabricating microelectronic structures using EUV (extreme ultraviolet) lithography. [Background technology]

[0003] As the semiconductor industry continues to follow Moore's Law, the demand for ever-shrinking feature sizes necessitates the use of thinner films to prevent pattern collapse. Thinner films necessitate the use of hard masks to transfer the pattern to the substrate. Extreme ultraviolet ("EUV") exposure is expected to be the method of choice for single-exposure lithography to achieve the necessary critical dimension ("CD") targets for the 7-nm node and beyond. Unfortunately, EUV lithography has been hindered by several challenges, including low throughput, stochastic effects, and adhesion issues.

[0004] Conventional three-layer stacks including a carbon-containing layer, a silicon-containing layer, and a photoresist tend to suffer from poor adhesion between the photoresist and the silicon underlayer, or from low etch rates of the silicon hardmask ("Si-HM") layer due to modifications intended to improve adhesion. Spin-on-silicon hardmasks that offer better adhesion to photoresist as well as high etch rates offer a manufacturing-friendly solution to improve lithography results and process times. Summary of the Invention [Means for solving the problem]

[0005] The present invention relates broadly to silicon hardmask compositions and methods of using these compositions in EUV processes.

[0006] In one embodiment, the present invention provides a method of forming a structure, the method comprising: providing a substrate, optionally including one or more intermediate layers; applying a composition onto the substrate, or the one or more intermediate layers, if present, to form a silicon hard mask layer; optionally forming a hexamethyldisilizane priming layer over the silicon hard mask layer; forming a photoresist layer over the hexamethyldisilizane priming layer if present, or over the silicon hard mask layer if a hexamethyldisilizane priming layer is not present; and exposing at least a portion of the photoresist layer to EUV radiation; The composition comprises a polysiloxane, The polysiloxane is an adhesion promoting monomer having a structure selected from one or both of the following structures: [ka] (Each R is C 1 ~About C 6 are individually selected from alkyl and hydrogen; n is from 1 to about 6; and each X is individually selected from glycidoxy, epoxy, epoxycycloalkyl, succinic anhydride, acetamide, and isocyanurate moieties; A surface modifying monomer having a structure selected from one or both of the following structures: [ka] (Each R 1 is C 1 ~About C 6From alkyl, and C 6 ~About C 20 aryl, Each R 2 is C 1 ~About C 6 are individually selected from alkyl and hydrogen; Each R 3 is C 1 ~About C 6 are individually selected from alkyl and hydrogen; m is from 1 to about 6; and each Y is independently selected from acetoxy, ester, and aryl moieties; and A densification monomer having a structure selected from one, two or three of the following structures: [ka] (Each R 4 is C 1 ~About C 6 alkyl and hydrogen; and one or both of:

[0007] A hexamethyldisilizane priming layer is optionally formed over the silicon hard mask layer, a photoresist layer is formed over the hexamethyldisilizane priming layer, if present, or over the silicon hard mask layer, if no hexamethyldisilizane priming layer is present, and at least a portion of the photoresist layer is exposed to EUV radiation.

[0008] In another embodiment, the method includes providing a substrate, optionally including one or more intermediate layers thereon. To form a silicon hard mask layer, a composition is applied to the substrate, or to the intermediate layer or layers, if present. The composition includes a polysiloxane, the polysiloxane being: adhesion promoting monomers including epoxy-functional trialkoxysilanes, anhydride-functional trialkoxysilanes, acetamide-functional trialkoxysilanes, trialkoxysilyl alkyl isocyanurates, and mixtures thereof; One or both of the following: Tetraalkoxysilane, and a surface modifying monomer selected from dialkoxysilanes, trialkoxysilanes, and combinations thereof; and one or both of:

[0009] An optional hexamethyldisilizane priming layer is formed over the silicon hard mask layer. A photoresist layer is formed over the hexamethyldisilizane priming layer, if present, or over the silicon hard mask layer, if no hexamethyldisilizane priming layer is present. At least a portion of the photoresist layer is exposed to EUV radiation. [Brief description of the drawings]

[0010] [Figure 1] 1 is an FTIR spectrum of silicon hard mask 1 (Example 1). [Diagram 2] 1 is a graph showing crosslinking temperatures tested for silicon hardmask 5 (Example 5). [Diagram 3] 1 is a table showing focus exposure matrix ("FEM") measurements of EUV lithography photoresists of samples tested in Example 9. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] More specifically, the present invention provides silicon hardmask compositions and methods of using these compositions to form microelectronic structures utilizing EUV (i.e., wavelengths less than about 20 nm, typically about 13.5 nm) lithography processes.

[0012] Silicon hard mask composition 1. Polymers used in the composition Preferred polymers are polysiloxanes that include one or more types of adhesion-promoting monomers and either or both of: (1) one or more types of surface-modifying monomers, and / or (2) one or more types of densifying monomers.

[0013] Preferred adhesion promoting monomers are [ka] The polymer is produced comprising repeating units having a structure selected from one or both of: Where: Each R is C 1 ~About C 6 Alkyl (preferably C 1 ~About C 3 alkyl) and hydrogen; n is from 1 to about 6, more preferably from 1 to about 3, and Each X is glycidoxy, epoxy, epoxycycloalkyl (preferably C 3 ~About C 10 and preferably C 1 ~About C 6 (cycloalkyl), succinic anhydride, acetamide and isocyanurate moieties.

[0014] Preferred surface modifying monomers are: [ka] The polymer is produced comprising repeating units having a structure selected from one or both of: Where: Each R 1 is C 1 ~About C 6 Alkyl (preferably C 1 ~About C 3 Alkyl) and C 6 ~About C 20 Aryl (preferably C6 ~About C 14 aryl), Each R 2 is C 1 ~About C 6 Alkyl (preferably C 1 ~About C 3 alkyl) and hydrogen; Each R 3 is C 1 ~About C 6 Alkyl (preferably C 1 ~About C 3 alkyl) and hydrogen; m is from 1 to about 6, more preferably from 1 to about 3, and Each Y is individually selected from acetoxy, ester, and aryl moieties. Preferred aryl moieties of Y are 6 ~About C 20 , more preferably C 6 ~About C 14 , most preferably C 6 It is.

[0015] Preferred densification monomers are [ka] To produce a polymer comprising repeating units having structures selected from one, two or three of: Here, each R 4 is C 1 ~About C 6 Alkyl (preferably C 1 ~About C 3 alkyl) and hydrogen.

[0016] It will be appreciated that the monomer ratios and wetting rates can be adjusted to provide the proper properties of the final composition, which may be tailored to accommodate various resist types, feature sizes and feature types (line / space, contact holes, etc.).

[0017] In one embodiment, the molar percentage of adhesion-promoting monomers or repeating units in the polysiloxane is preferably about 2% to about 50%, more preferably about 5% to about 35%, and even more preferably about 10% to about 20%. The molar percentage of surface-modifying monomers is preferably about 5% to about 90%, more preferably about 10% to about 80%, and even more preferably about 40% to about 70%. The molar percentage of densifying monomers is preferably about 0% to about 80%, more preferably about 10% to about 70%, and even more preferably about 15% to about 50%.

[0018] In another embodiment, the molar percentage of adhesion-promoting monomers or repeating units in the polysiloxane is preferably about 2% to about 50%, more preferably about 5% to about 35%, and more preferably about 10% to about 20%. The molar percentage of surface-modifying monomers is preferably about 0% to about 70%, more preferably about 10% to about 70%, and even more preferably about 15% to about 70%. The molar percentage of densifying monomers is preferably about 2% to about 90%, more preferably about 10% to about 80%, and even more preferably about 15% to about 70%.

[0019] In yet another embodiment, the molar percentage of adhesion-promoting monomers or repeating units in the polysiloxane is about 0% to about 30%, preferably about 0.01% to about 30%, more preferably about 0.01% to about 20%, and even more preferably about 0.1% to about 15%. The molar percentage of surface-modifying monomers is preferably about 0% to about 70%, more preferably about 5% to about 60%, and even more preferably about 15% to about 50%. The molar percentage of densifying monomers is preferably about 30% to about 95%, more preferably about 40% to about 80%, and even more preferably about 50% to about 70%.

[0020] In one embodiment, the polysiloxane consists essentially of, or consists of, one or both of one or more types of adhesion promoting monomers, one or more types of surface modifying monomers, and / or one or more types of densifying monomers. In another embodiment, the polysiloxane consists essentially of, or consists of, one or more types of adhesion promoting monomers, one or more types of surface modifying monomers, and one or more types of densifying monomers.

[0021] 2. Polymerization Materials and Methods Polymers for use in silicon hard mask compositions are preferably synthesized from hydrolyzable silane monomers, with a particularly preferred synthesis method being the sol-gel process. Examples of hydrolyzable silane monomers include tetraethoxysilane ("TEOS"), tetramethyl orthosilicate ("TMOS"), methyltrimethoxysilane ("MTMS"), methyltriethoxysilane ("MTEOS"), dimethyldimethoxysilane ("DMDMS"), dimethyldiethoxysilane ("DMDEOS"), phenyltrimethoxysilane ("PTMS"), phenethyltrimethoxysilane ("PETMS"), 2-(carbomethoxy)ethyltrimethoxysilane ("CMETMS"), acetoxyethyl-trimethoxysilane, ethyltrimethoxysilane ("ETMS"), n-butyltrimethoxysilane ("BuTMS"), (3-glycidyltrimethoxysilane ("Glycine"), and the like. and combinations thereof.

[0022] As noted above, the polymers used in these compositions contain at least one or more types of adhesion promoting monomers, preferably as copolymers with one or both of: (1) one or more types of surface modifying monomers, and (2) one or more types of densifying monomers.

[0023] Preferred starting compounds for use as adhesion-promoting monomers, which would form the aforementioned structures (I) and (II) of polysiloxanes, include trialkoxysilanes (preferably C 1 ~About C 6 Alkoxy, more preferably C 1 ~About C 3 Particularly preferred examples of the above are selected from (3-glycidoxypropyl)trimethoxysilane, 5,6-epoxyhexyl-triethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, [3-(triethoxysilyl)propyl]succinic anhydride, (3-acetamidopropyl)trimethoxysilane, (1,3-di-2-propen-1-yl)-5-(([3-triethoxysilylpropyl])-(1,3,5-triazine-2,4,6(1H,3H,5H)-trione) and mixtures thereof.

[0024] In embodiments where a surface modification monomer is included, the monomer functions to adjust the surface energy of the hard mask layer formed from the composition, thus providing compatibility between the hard mask layer and the EUV resist in certain embodiments. Preferred such starting compounds for use as surface modification monomers that would result in polysiloxane structures (III) and (IV) include dialkoxysilanes, trialkoxysilanes, and combinations thereof. In either case, the alkoxy is preferably C 1 ~About C 6 Alkoxy, more preferably C 1 ~About C 3Furthermore, the Si atom of the selected surface modification monomer is preferably bonded to two alkyl, aryl and / or alkylaryl moieties (in the case of dialkoxysilanes) or to one alkyl, aryl or alkylaryl moiety (in the case of trialkoxysilanes). In either case, the preferred alkyl is C 1 ~About C 6 , preferably C 1 ~About C 3 and preferred aryl is C 6 ~About C 20 , more preferably C 6 ~About C 14 , most preferably C 6 and preferred alkylaryls are those having C 1 ~About C 6 (More preferably C 1 ~About C 3 ) and in the aryl portion is C 6 ~About C 20 (More preferably C 6 ~About C 14 , most preferably C 6 In a further embodiment, the surface modification monomer lacks one or all of the epoxy, anhydride, acetamide and / or isocyanurate functional groups.

[0025] Particularly preferred surface modification monomers are selected from methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, phenethyl-trimethoxysilane, 2-(carbomethoxy)ethyltrimethoxysilane, acetoxyethyltrimethoxysilane, ethyl-trimethoxysilane, n-butyltrimethoxysilane and mixtures thereof.

[0026] Densifying monomers for use with these polymers provide hydrophilic silanol groups and help provide thermally driven crosslinking during the post-application bake process by providing crosslinking sites for the final crosslinked polymer structure in the cured hardmask layer. Preferred starting compounds for use as densifying monomers that would form the aforementioned structures (V), (VI) and (VII) of polysiloxanes include tetraalkoxysilanes (preferably C 1 ~About C 6 Alkoxy, more preferably C 1 ~About C 3 alkoxy), with tetraethoxysilane and / or tetramethyl orthosilicate being particularly preferred.

[0027] The polymer is synthesized by dissolving the desired monomers as described above in a suitable polymerization solvent, preferably in an amount to achieve the molar ratios described above. The polymerization solvent may include, but is not limited to, propylene glycol monomethyl ether acetate ("PGMEA"), propylene glycol methyl ether ("PGME"), propylene glycol ethyl ether ("PGEE"), cyclohexanone, ethyl lactate, propanol, butanol, and mixtures thereof. Water is added to the reaction mixture to hydrolyze the silane monomers while a catalyst for the sol-gel condensation is simultaneously added. Preferably, H 2 The molar ratio range of O / monomer is about 1:1 to about 10:1, more preferably about 2:1 to about 8:1. Suitable catalysts include, but are not limited to, mineral acids (such as hydrochloric acid or nitric acid), acetic acid, maleic acid, and combinations thereof. Hydrolysis is preferably allowed to proceed at room temperature for about 1 hour to about 48 hours, more preferably about 4 hours to about 24 hours, and even more preferably about 16 hours. The hydrolyzed monomer is then copolymerized at a temperature of about 40°C to about 120°C, preferably about 60°C to about 100°C, and more preferably about 90°C, for about 0.5 hours to about 72 hours, preferably about 1 hour to about 48 hours, and more preferably about 5 hours to about 16 hours.

[0028] The number average molecular weight (Mn) of the resulting polymer, as measured by gas permeation chromatography (GPC) using polystyrene standards, is preferably about 500 g / mol to about 3,000 g / mol, more preferably about 800 g / mol to about 2,000 g / mol. The weight average molecular weight (Mw) of the polymer, as measured by GPC, is preferably in the range of about 600 g / mol to about 10,000 g / mol, more preferably about 1,000 g / mol to about 8,000 g / mol, and even more preferably about 1,500 g / mol to about 5,000 g / mol.

[0029] 3. Preparation of the Composition The formed polymer is then dispersed or dissolved in a solvent system to form a silicon hardmask composition. Preferred solvent systems include solvents selected from the group consisting of PGMEA, PGME, PGEE, propylene glycol n-propyl ether ("PnP"), ethyl lactate, cyclohexanone, gamma-butyrolactone ("GBL"), methyl isobutyl carbinol, and mixtures thereof. The solvent system is preferably utilized at a level of about 80% to about 99.9% by weight, more preferably about 90% to about 99.9%, and even more preferably about 99.0% to about 99.9%, based on the total weight of the composition being 100% by weight. The composition used to form the silicon hardmask layer preferably contains a solids content of about 0.1% to about 20% by weight solids, more preferably about 0.1% to about 10% by weight solids, and even more preferably about 0.1% to about 1.0% by weight solids, based on the total weight of the composition being 100% by weight.

[0030] The silicon hard mask layer composition is formed by mixing the above-mentioned components in a solvent system in which optional components (e.g., surfactants) are also dispersed. In some embodiments, additives are utilized. Preferably, the additives are simply mixed into the silicon hard mask layer composition. Preferred additives include catalysts such as benzyltriethylammonium chloride ("BTEAC"), tert-butylphosphonium bromide ("TBPB"), ethyltriphenylphosphonium bromide ("EtPPB"), and triethoxy-3-(2-imidazolin-1-yl)propylsilane. Another additive that may be used in the hard mask composition is a photoacid generator ("PAG") such as tris(hydroxyphenyl)sulfonium mesylate, tris(hydroxyphenyl)sulfonium triflate, and combinations thereof. When additives are present, they should be present (cumulatively or individually) in the composition at a level of about 0.01% to about 2.0% by weight, preferably about 0.1% to about 1.0% by weight, based on the total weight of solids in the composition being 100% by weight.

[0031] In some embodiments, the hardmask composition consists essentially of, or consists of, a polysiloxane, a solvent system, a catalyst, and a photoacid generator. In some embodiments, the hardmask composition consists essentially of, or consists of, a polysiloxane, a solvent system, and a catalyst. In further embodiments, the hardmask composition consists essentially of, or consists of, a polysiloxane, a solvent system, and a photoacid generator. In further embodiments, the hardmask composition consists essentially of, or consists of, a polysiloxane and a solvent system.

[0032] Methods of using silicon hardmask compositions In the method according to the invention, a hard mask composition as described above is formed into a layer on a substrate surface or on an intermediate layer (described below) present on the substrate surface. The substrate is preferably made of silicon, SiGe, SiO, or a combination of both, although any microelectronic substrate may be used. 2 , Si 3 N 4, SiON, SiCO:H (such as that sold under the name Black Diamond), Aluminum, Tungsten, Tungsten silicide, Gallium arsenide, Germanium, Tantalum, Tantalum nitride, Ti 3 N 4 , Hafnium, HfO 2 The substrate may be a semiconductor substrate such as silicon, ruthenium, indium phosphide, glass or mixtures thereof. The substrate may have a flat surface or may contain topographical features (via holes, trenches, contact holes, raised features, lines, etc.). As used herein, "topography" refers to the height or depth of structures in or on the substrate surface.

[0033] A carbon-rich layer may be formed on the substrate or any intermediate layer. The carbon-rich layer may be formed by any known application method, but one preferred method is spin-coating at a speed of about 1,000 to about 5,000 rpm, preferably about 1,250 to about 1,750 rpm, for about 30 to about 120 seconds, preferably about 45 to about 75 seconds. The term "carbon-rich" refers to a layer formed from a composition that contains more than about 50% by weight carbon, preferably more than about 70% by weight carbon, more preferably about 75% to about 80% by weight carbon, based on 100% by weight of the total solids in the composition. Suitable carbon-rich layers are selected from the group consisting of spin-on carbon layers (SOC), amorphous carbon layers, and carbon planarization layers.

[0034] Exemplary carbon-rich layers generally comprise a polymer dissolved or dispersed in a solvent system with one or more of the following optional components: acid and / or base quenchers, catalysts, crosslinkers, and surface-modifying additives. Preferred compositions are suitable for forming thick layers and have a solids content of preferably about 0.1% to about 70%, more preferably about 5% to about 40%, and even more preferably about 10% to about 30% by weight, based on the total weight of the composition being 100% by weight. After the carbon-rich composition is applied, it is preferably heated to a temperature of about 100° C. to about 400° C., more preferably about 160° C. to about 350° C., for about 30 seconds to about 120 seconds, preferably about 45 seconds to about 60 seconds, to evaporate the solvent. The thickness of the carbon-rich layer after baking (average measurement of five points by an ellipsometer) is preferably about 10 nm to about 120 nm, more preferably about 20 nm to about 100 nm, and even more preferably about 50 nm to about 60 nm. The carbon-rich layer may be formed by other known application methods, such as chemical vapor deposition ("CVD"), plasma enhanced chemical vapor deposition ("PECVD"), atomic layer deposition ("ALD") or plasma enhanced atomic layer deposition ("PEALD").

[0035] The silicon hard mask layer according to the present invention may be applied adjacent to the carbon-rich material or the substrate or any intermediate layer. The silicon hard mask layer is preferably applied by spin coating at a speed of about 1,000 rpm to about 3,000 rpm, preferably about 1,500 rpm to about 2,000 rpm, for about 30 seconds to about 120 seconds, preferably about 30 seconds to about 60 seconds. After the silicon hard mask is applied, it is preferably heated to a temperature of about 150°C to about 300°C, more preferably about 200°C to about 250°C, for about 30 seconds to about 120 seconds, preferably about 30 seconds to about 60 seconds, in order to evaporate the solvent. During this baking, a sol-gel reaction occurs, thus crosslinking the material. The thickness of the hard mask layer after baking (average measurement of five points by an ellipsometer) is preferably about 2 nm to about 50 nm, more preferably about 5 nm to about 30 nm, even more preferably about 10 nm to about 25 nm. The hardmask layer should have an etch rate in a fluorine-rich plasma atmosphere that is at least about 1.5 times that of the photoresist (e.g., chemically amplified, metal oxide, or chain scission photoresist), and the carbon-rich layer should have an etch rate in an oxygen-rich plasma etch atmosphere that is at least about 1.5 times that of the silicon hardmask layer.

[0036] After the silicon hard mask layer is baked, an EUV photoresist (i.e., imaging layer) can be applied to the silicon hard mask layer to form a photoresist layer. The photoresist layer can be formed by any conventional method, but one preferred method involves spin-coating a photoresist composition at a speed of about 350 rpm to about 4,000 rpm (preferably about 1,000 rpm to about 2,500 rpm) for about 10 seconds to about 60 seconds (preferably about 10 seconds to about 30 seconds). The photoresist layer is then optionally post-apply baked ("PAB") at a temperature of at least about 70°C, preferably about 80°C to about 150°C, more preferably about 100°C to about 150°C, for about 30 seconds to about 120 seconds. The thickness of the photoresist layer after baking (average measurement of five points by an ellipsometer) is typically about 5 nm to about 120 nm, preferably about 10 nm to about 50 nm, more preferably about 20 nm to about 40 nm.

[0037] A hexamethyldisilizane ("HMDS") priming process may be performed prior to coating the photoresist, in which the wafer is exposed to HMDS vapor in a sealed chamber for 90 seconds while being heated at 150° C.

[0038] The photoresist layer is then irradiated with a dose of approximately 5 mJ / cm 2 ~about 100mJ / cm 2 , preferably about 10 mJ / cm 2 ~about 80mJ / cm 2 , more preferably about 20 mJ / cm 2 ~about 60mJ / cm 2The photoresist layer is patterned by exposure to EUV radiation. More specifically, the photoresist layer is exposed with a mask that is aligned above the surface of the photoresist layer. The mask has portions designed to allow the EUV radiation to reflect off the mask and contact the surface of the photoresist layer. The remaining portions of the mask are designed to be light absorbing to prevent the radiation from contacting the surface of the photoresist layer at predetermined portions. Those skilled in the art will readily appreciate that the arrangement of the reflective and absorbing portions is designed based on the desired pattern to be formed in the photoresist layer, and ultimately in the substrate or any intermediate layers.

[0039] After EUV exposure, the photoresist layer is preferably post-exposure baked ("PEB") at a temperature less than about 180°C, preferably from about 60°C to about 140°C, and more preferably from about 80°C to about 130°C, for about 30 seconds to about 120 seconds (preferably from about 30 seconds to about 90 seconds).

[0040] The photoresist layer is then contacted with a developer to form a pattern. Depending on whether a positive- or negative-working photoresist is used, the developer either removes the exposed portions of the photoresist layer or removes the unexposed portions of the photoresist layer to form the pattern. The pattern is then transferred to the silicon hard mask layer, any intermediate layers present, and finally to the substrate. This pattern transfer can be achieved by plasma etching (e.g., CF 4 Etching agent, O 2 This can be accomplished via a wet etching or development process. In embodiments where the pattern is transferred from the photoresist layer to the substrate via etching, the etch rate of the silicon hard mask layer relative to a typical EUV photoresist is preferably at least about 1x, and preferably about 1.5x to about 2x.

[0041] Whether the pattern transfer is by etching or by developing, the resulting features have high resolution. For example, with the method of the present invention, a resolution of less than about 40 nm half pitch, preferably less than about 30 nm half pitch, can be achieved. The silicon hard mask layer improves the collapse margin of the final features. The collapse margin is quantified by the difference in dose versus size from the maximum dose where the structure still stands, or from the minimum dose in the case of negative tone developing resist or negative tone imaging resist.

[0042] Further advantages of various embodiments of the present invention will become apparent to those skilled in the art upon reviewing the disclosure herein and the following examples. It will be recognized that the various embodiments described herein are not necessarily mutually exclusive, unless otherwise indicated herein. For example, features described or depicted in one embodiment may be included in other embodiments, but are not necessarily included. Thus, the present invention encompasses various combinations and / or integrations of the specific embodiments described herein.

[0043] As used herein, the term "and / or," when used in a list of two or more items, means that any of the listed items may be used alone, or any combination of two or more of the listed items may be used. For example, if a composition is described as including or excluding components A, B, and / or C, the composition may include or exclude only A, only B, only C, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C.

[0044] The present specification also uses numerical ranges to quantify certain parameters related to various embodiments of the present invention. When numerical ranges are provided, it should be understood that such ranges should be interpreted as providing literal support for claim limitations that recite only the lower value of the range as well as for claim limitations that recite only the upper value of the range. For example, a numerical range disclosed as about 10 to about 100 provides literal support for the statement "greater than about 10" (without a stated upper limit) in the claim and the statement "less than about 100" (without a stated lower limit) in the claim. EXAMPLES

[0045] The following examples describe the methods according to the present invention, however, it should be understood that these examples are provided by way of illustration and therefore should not be construed in any way as a limitation on the scope of the invention encompassed.

[0046] [Example 1] Synthesis and formulation of silicon hardmask 1 In this example, 3.95 grams of TEOS (Gelest, Morrisville, PA, USA), 7.62 grams of MTMS (Gelest, Morrisville, PA, USA), 2.62 grams of PETMS (Gelest, Morrisville, PA, USA), and 3.54 grams of GlyTMS (Gelest, Morrisville, PA, USA) were dissolved in 36 grams of PGME (KMG Electronic Chemicals, Fort Worth, TX, USA). 8.78 grams of 3N acetic acid (VWR, Batavia, IL, USA) was then added dropwise to the solution to hydrolyze the siloxane monomers, and the solution was stored at room temperature for about 16 hours. The reaction was then incubated at 4°C for 20 min at 20°C for 1 hour at 4°C for 2 hours at 20°C for 1 hour at 20 ... 2 It was kept under cover and heated to 90° C. for 20 hours to produce Mother Liquor 1. The resulting polymer had a molecular weight of ∼2000 and a polydispersity index ("PDI") of 1.6, as measured using a TOSOH ECOSEC HLC-8320 gel permeation chromatography with THF as the mobile phase.

[0047] Next, 5.89 grams of mother liquor 1 was dissolved in 110.9 grams of PGME and 12.88 grams of PGMEA (KMG Electronic Chemicals, Fort Worth, TX) (90:10) to which was added 0.29 grams of TBPB solution (0.2 wt % in PGME). The resulting formulation was mixed on a mixing wheel overnight and the resulting formulation had a solids content of about 0.9 wt %.

[0048] [Example 2] Synthesis and formulation of silicon hardmask 2 In this procedure, 3.95 grams of TEOS, 4.90 grams of MTMS, 6.78 grams of PETMS, and 3.54 grams of GlyTMS were dissolved in 44 grams of PGME. Then, 8.78 grams of 3N acetic acid was added dropwise to the solution to hydrolyze the siloxane monomers, and the solution was stored at room temperature for about 16 hours. The reaction was then allowed to proceed under N 2 It was kept under cover and heated to 90 °C for 20 h to produce mother liquor 2. The resulting polymer had a molecular weight of ∼2000 and a polydispersity index (PDI) of 1.6, measured using a TOSOH ECOSEC HLC-8320 gel permeation chromatography with THF as the mobile phase.

[0049] Next, 5.9 grams of Mother Liquor 2 was dissolved in 110.1 grams of PGME and 12.8 grams of PGMEA (90:10) to which was added 0.29 grams of TBPB solution (0.2 wt % in PGME). The resulting formulation was mixed overnight on a mixing wheel. The resulting formulation had a solids content of about 0.9 wt %.

[0050] [Example 3] Synthesis and formulation of silicon hardmask 3 In this example, 3.95 grams of TEOS, 7.62 grams of MTMS, 2.26 grams of PETMS, and 3.93 grams of EpoTMS (Gelest, Morrisville, PA, USA) were dissolved in 35 grams of PGME. 8.78 grams of 3N acetic acid was then added dropwise to the solution to hydrolyze the siloxane monomers, and the solution was stored at room temperature for approximately 16 hours. The reaction was cooled to room temperature and cooled to room temperature. 2 It was kept under cover and heated to 90 °C for 17.5 h to produce mother liquor 3. The resulting polymer had a molecular weight of ∼2300 and a polydispersity index (PDI) of 1.7, as measured using a TOSOH ECOSEC HLC-8320 gel permeation chromatography with THF as the mobile phase.

[0051] Next, 7.0 grams of mother liquor 3 was dissolved in 136.8 grams of PGME and 15.9 grams of PGMEA (90:10) to which was added 0.35 grams of TBPB solution (0.2 wt % in PGME). The resulting formulation was mixed on a mixing wheel overnight and the resulting formulation had a solids content of about 0.9 wt %.

[0052] [Example 4] Synthesis and formulation of silicon hardmask 4 In this procedure, 3.95 grams of TEOS, 8.98 grams of MTMS, and 3.54 grams of GlyTMS were dissolved in 33 grams of PGME. Then, 8.78 grams of 3N acetic acid was added dropwise to the solution to hydrolyze the siloxane monomers, and the solution was stored at room temperature for approximately 16 hours. The reaction was cooled to room temperature and cooled to room temperature. 2 It was kept under cover and heated to 90 °C for 17.5 h to produce mother liquor 4. The resulting polymer had a molecular weight of ∼1500 and a polydispersity index (PDI) of 1.5, as measured using a TOSOH ECOSEC HLC-8320 gel permeation chromatography with THF as the mobile phase.

[0053] Next, 4.98 grams of mother liquor 4 was dissolved in 84.9 grams of PGME and 9.9 grams of PGMEA (90:10) to which was added 0.26 grams of TBPB solution (0.2 wt % in PGME). The resulting formulation was mixed overnight on a mixing wheel. The resulting formulation had a solids content of about 1.0 wt %.

[0054] [Example 5] Synthesis and formulation of silicon hardmask 5 In this example, 11.4 grams of TEOS, 4.76 grams of MTMS, and 2.36 grams of GlyTMS were dissolved in 29 grams of PGME. 8.78 grams of 3N acetic acid was then added dropwise to the solution to hydrolyze the siloxane monomers, and the solution was stored at room temperature for approximately 16 hours. 2 It was kept under cover and heated to 90° C. for 4 hours to produce mother liquor 5. The resulting polymer had a molecular weight of ∼3000 and a PDI of 2.2, as determined using a TOSOH ECOSEC HLC-8320 gel permeation chromatography with THF as the mobile phase.

[0055] Next, 7.0 grams of Mother Liquor 5 was dissolved in 173.17 grams of PGME and 19.90 grams of PGMEA (90:10) and mixed overnight on a mixing wheel. The resulting formulation had a solids content of about 0.7% by weight.

[0056] [Example 6] Synthesis and formulation of silicon hardmask 6 In this procedure, 11.65 grams of TEOS and 7.83 grams of MTEOS (Gelest, Morrisville, PA, USA) were dissolved in 26 grams of PGME. 8.78 grams of 3N acetic acid was then added dropwise to the solution to hydrolyze the siloxane monomers, and the solution was stored at room temperature for approximately 16 hours. The reaction was cooled to room temperature and cooled to room temperature for approximately 16 hours. 2 It was kept under cover and heated to 90° C. for 4 hours to produce mother liquor 6. The resulting polymer had a molecular weight of ∼2200 and a PDI of 1.0, as measured using a TOSOH ECOSEC HLC-8320 gel permeation chromatography with THF as the mobile phase.

[0057] Next, 9.42 grams of mother liquor 6 was dissolved in 98.77 grams of PGME and 11.81 grams of PGMEA (90:10) and mixed on a mixing wheel overnight, the resulting formulation had a solids content of about 1.57% by weight.

[0058] [Example 7] FTIR analysis of silicon hard mask 1 FTIR spectra of the silicon hard mask of Example 1 were obtained using a Thermal Scientific Nicolet is50 FTIR spectrometer. To prepare the sample, the formulation of Example 1 was reproduced and less solvent was added to reach a solid content of ∼10 wt % and then spin-coated onto a silicon wafer (NESTEC, experimental grade) at a spin speed of 1,500 rpm for 60 seconds. After spinning, the layer was baked on a hotplate at 205°C for 60 seconds to form a crosslinked film. The total thickness of the layer was ∼250 nm. The film thickness was measured using an M-2000 ellipsometer (JA Woollam, Lincoln, NE). The film was then scraped off from the wafer into a powder state. The powder sample was characterized under ATR-FTIR mode. Figure 1 shows the FTIR spectrum.

[0059] [Example 8] Characterization of silicon hardmask 5 The crosslinking temperature was determined using a strip test with PGME as the stripping solvent. Silicon hard mask 5 (Example 5) was spin coated onto the substrate at 1,500 rpm and baked at the temperatures shown in Figure 2. The thickness was determined as described in Example 7. PGME was then pooled onto the wafer surface and spun dry at 1,500 rpm for 60 seconds. The film thickness was determined again to see if there was any film loss. Figure 2 shows these results, with negative thickness loss representing film swelling.

[0060] The surface contact angle of the silicon hard mask 5 was determined using an AST Optima (B5RM5208-143) contact angle measurement tool. The contact angle of the material of Example 5 was measured five times at different spots and averaged. Water and methylene iodide were used as the drop solvent. The final surface contact angle of the material was 61.8 (H 2 O) and 51.9 (CH 2 I 2 ) was.

[0061] [Example 9] Lithography results of silicon hard mask 1 A layer of OptiStack® SOC120 material (Blu-ray Sciences, Rolla, MO) was spin-coated at 1,486 rpm for 30 seconds and baked at 220° C. for 60 seconds to form a 60 nm film. Silicon hard mask 1 (Example 1) was spin-coated onto the layer of OptiStack® SOC120 material by spin-coating at 1,406 rpm for 30 seconds and baked at 205° C. for 60 seconds to form a 25 nm film. EUV resist JSR4267 (supplied by IMEC) was coated onto the hard mask layer by spin-coating at 1,040 rpm for 25 seconds followed by baking at 130° C. for 60 seconds to form a 35 nm coat. The resist was then exposed using the parameters shown in Table 1. An NXE3300 EUV scanner was used for the imaging step and a TEL Pro Z track was used for the wafer process. FIG. 3 shows the lithography quality using the silicon hard mask layer of Example 1 under the resist.

[0062] [Table 1]

Claims

1. 1. A method of forming a structure, the method comprising: providing a substrate, optionally including one or more intermediate layers; applying a composition onto the substrate, or the one or more intermediate layers, if present, to form a silicon hard mask layer; Optionally, forming a hexamethyldisilizane priming layer on the silicon hard mask layer; forming a photoresist layer over the hexamethyldisilizane priming layer, if present, or over the silicon hard mask layer, if no hexamethyldisilizane priming layer is present; and exposing at least a portion of the photoresist layer to EUV radiation; The composition comprises a polysiloxane and a solvent other than water, The polysiloxane is an adhesion promoting monomer having a structure selected from one or both of the following structures: 【Chemistry 1】 (Each R is C １ ~C ６ are individually selected from alkyl and hydrogen; n is 1 to 6, and Each X is a glycidoxy group, an epoxy group, an epoxycycloalkyl group, a succinic anhydride group, acetamide groups, and isocyanurate moieties), A surface modifying monomer having a structure selected from one or both of the following structures: 【Chemistry 2】 (Each R １ is C １ ~C ６ From alkyl, and C ６ ~C ２０ aryl, Each R ２ is C １ ~C ６ are individually selected from alkyl and hydrogen; Each R ３ is C １ ~C ６ are individually selected from alkyl and hydrogen; m is 1 to 6, and each Y is independently selected from acetoxy, ester, and aryl moieties; and A densification monomer having a structure selected from one, two or three of the following structures: 【Chemistry 3】 (Each R ４ is C １ ~C ６ alkyl and hydrogen); and one or both of:

2. The method of claim 1 , wherein the polysiloxane comprises both the surface modifying monomer and the densifying monomer.

3. The polysiloxane is 2 mol % to 50 mol % of an adhesion promoting monomer; 5 mol % to 90 mol % of a surface modifying monomer; 80 mol % or less of a densifying monomer; The method of claim 1 , comprising:

4. The polysiloxane is 2 mol % to 50 mol % of an adhesion promoting monomer; 70 mol % or less of a surface modifying monomer; 2 mol % to 90 mol % of a densifying monomer; The method of claim 1 , comprising:

5. The polysiloxane is 0.01 mol % to 30 mol % of an adhesion promoting monomer; 70 mol % or less of a surface modifying monomer; 30 mol % to 95 mol % of a densifying monomer; The method of claim 1 , comprising:

6. The substrate may be made of silicon, SiGe, or SiO ２ , Si ３ N ４ , SiON, SiCO:H, aluminum, tungsten, tungsten silicide, gallium arsenide, germanium, tantalum, tantalum nitride, Ti ３ N ４ , Hafnium, HfO ２ The method of any one of claims 1 to 5, wherein the metal is selected from the group consisting of ruthenium, indium phosphide, glass and mixtures thereof.

7. The method of any one of claims 1 to 6, further comprising forming a pattern in the photoresist layer after the exposure of the photoresist layer to EUV radiation.

8. The method of any one of claims 1 to 7, further comprising transferring the pattern into the silicon hard mask layer, into the intermediate layer if present, and into the substrate.

9. The method according to any one of claims 1 to 8, wherein an intermediate layer is present, said intermediate layer being a carbon rich layer comprising more than 50% by weight of carbon.

10. 1. A method of forming a structure, the method comprising: providing a substrate thereon, which may include one or more intermediate layers; applying a composition onto the substrate, or the one or more intermediate layers, if present, to form a silicon hard mask layer; Optionally, forming a hexamethyldisilizane priming layer on the silicon hard mask layer; forming a photoresist layer over the hexamethyldisilizane priming layer, if present, or over the silicon hard mask layer, if no hexamethyldisilizane priming layer is present; and exposing at least a portion of the photoresist layer to EUV radiation; The composition comprises a polysiloxane and a solvent other than water, the polysiloxane comprising an adhesion promoting monomer selected from (3-glycidoxypropyl)trimethoxysilane, 5,6-epoxyhexyl-triethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, [3-(triethoxysilyl)propyl]succinic anhydride, (3-acetamidopropyl)trimethoxysilane, (1,3-di-2-propen-1-yl)-5-(([3-triethoxysilylpropyl])-(1,3,5-triazine-2,4,6(1H,3H,5H)-trione), or combinations thereof; Tetraalkoxysilane, and and one or both of a surface modification monomer selected from methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxy-silane, phenyltrimethoxysilane, phenethyl-trimethoxysilane, 2-(carbomethoxy)ethyltrimethoxy-silane, acetoxyethyltrimethoxysilane, ethyl-trimethoxysilane, n-butyltrimethoxysilane, or combinations thereof.

11. 11. The method of claim 10, wherein the tetraalkoxysilane is selected from one or both of tetraethoxysilane or tetramethylorthosilicate.

12. The method of claim 10 or 11, wherein the polysiloxane comprises both the tetraalkoxysilane and the surface modifying monomer.

13. The polysiloxane is 2 mol % to 50 mol % of an adhesion promoting monomer; 5 mol % to 90 mol % of a surface modifying monomer; 80 mol % or less of a densifying monomer; The method according to any one of claims 10 to 12, comprising:

14. The polysiloxane is 2 mol % to 50 mol % of an adhesion promoting monomer; 70 mol % or less of a surface modifying monomer; 2 mol % to 90 mol % of a densifying monomer; The method according to any one of claims 10 to 12, comprising:

15. The polysiloxane is 0.01 mol % to 30 mol % of an adhesion promoting monomer; 70 mol % or less of a surface modifying monomer; 30 mol % to 95 mol % of a densifying monomer; The method according to any one of claims 10 to 12, comprising:

16. The substrate may be made of silicon, SiGe, or SiO ２ , Si ３ N ４ , SiON, SiCO:H, aluminum, tungsten, tungsten silicide, gallium arsenide, germanium, tantalum, tantalum nitride, Ti ３ N ４ , Hafnium, HfO ２ The method of any one of claims 10 to 15, wherein the metal is selected from the group consisting of ruthenium, indium phosphide, glass and mixtures thereof.

17. The method of any one of claims 10 to 16, further comprising forming a pattern in the photoresist layer after the exposure of the photoresist layer to EUV radiation.

18. A method according to any one of claims 10 to 17, wherein an intermediate layer is present, said intermediate layer being a carbon rich layer comprising more than 50% by weight of carbon.

Images