TW202406905A - Enhanced euv photoresists and methods of their use - Google Patents

Abstract

The present application for patent discloses a composition of matter comprising a solvent; and an ester having a chemical structure chosen from (I): Wherein X and Y are the same or different, wherein X, Y and R1-R4 and are branched or unbranched, substituted or unsubstituted alkyl chains of 1-24 carbon atoms having 0-16 heteroatoms substituted into the chain, are substituted or unsubstituted phenyl groups, heteroaromatic groups, or fused aromatic or fused heteroaromatic groups or combinations of both.

Description

Enhanced EUV photoresists and methods of use

This patent application is in the field of nanolithography materials, and more specifically, in the field of molecular glass photoresists containing zwitterionic materials, their formulations and their uses.

It is well known that the manufacturing process of various electronic or semiconductor devices such as ICs, LSIs, etc. involves the fine patterning of a photoresist layer on the surface of a substrate material such as a semiconductor silicon wafer. This fine patterning process is traditionally performed by photolithography, in which the substrate surface is uniformly coated with a positive or negative photosensitive composition to form a thin layer and selectively illuminated with actinic rays such as ultraviolet (UV) light. ), deep ultraviolet, vacuum ultraviolet, extreme ultraviolet, x-rays, electron beams and ion beams) through a transmission or reflection mask, followed by a development process to selectively dissolve areas that are or are not exposed to actinic rays, respectively The photosensitive layer in the substrate leaves a patterned photoresist layer on the surface of the substrate. The patterned photoresist layer thus obtained can be used as a mask in subsequent processes such as etching on the substrate surface. The fabrication of structures with nanoscale dimensions is an area of considerable interest as it enables electronic and optical devices that exploit novel phenomena such as quantum confinement effects and also allows for greater component packaging densities. As a result, photoresist patterns are required to have ever-increasing fineness, which can be achieved by using actinic rays with shorter wavelengths than conventional ultraviolet light. Accordingly, the current situation is to use electron beams (e-beams), excimer laser beams, EUV, BEUV and X-rays to replace traditional ultraviolet light as short-wavelength actinic rays. Needless to say, the minimum achievable size depends partly on the properties of the resist material and partly on the wavelength of the actinic rays. Various materials have been proposed as suitable resist materials. For example, in the case of negative photoresists based on polymer cross-linking, there is an inherent resolution limit of about 10 nm, which is the approximate radius of a single polymer molecule.

It is also known to apply a technique called "chemical amplification" to resist materials. Chemically amplified resist materials are typically multi-component formulations containing a matrix material, often the primary polymer component, such as polyhydroxystyrene (PHOST) protected with acid-labile groups and a photoacid generator (PAG). ) resin, and one or more additional components that impart the desired properties to the resist. The matrix material contributes to properties such as etch resistance and mechanical stability. By definition, chemical amplification occurs through a catalytic process on PAG that results in a single irradiation event that causes the transformation of multiple resistor molecules. The acid generated by PAG reacts catalytically with the polymer to lose functional groups or cause cross-linking events. The reaction rate can be driven, for example, by heating the photoresist film. In this way, the material's sensitivity to actinic radiation is greatly increased, since a small number of radiation events can cause a large number of solubility change events. As mentioned above, chemically amplified resists can be either positive or negative working.

Some chemical amplification resistors do not use large polymers. In situations where nanoscale patterning is required, low molecular weight polymers or even small molecules can be used as resist matrix materials. These are sometimes referred to as "molecular glass" resistors (MGRs), in which case they include molecules such as oligomers, polyaromatic derivatives, discotic liquid crystals, fullerenes, macrocycles, small non- crystalline, and other low molecular weight resistors. Although MGRs may have many potential advantages compared to polymeric chemical amplification resistors, there are still some challenges that such materials may pose. The removal and subsequent volatilization of protecting groups in positive molecular resists may result in a loss of up to approximately 50% of the resist mass, which may well result in a loss of pattern quality. The small size of molecular resist compounds, and often correspondingly low glass transition temperatures, can also restore material integrity, but may compromise pattern quality.

As feature size requirements continue to decrease, for example below 20 nm, there is a need to control cationic polymerization and/or cross-linking in negative processing systems. Photoresists based on acid-catalyzed deprotection, such as in positive-tone processing systems, utilize alkali quenchers to control photoacid migration to areas that do not require deprotection. Typical epoxy-based negative-working photoresists are initiated by light-generated acids, but this living polymerization and cross-linking species is not photoacid (see Figure 1). It can be readily seen that this process involves photoacid protonation of the epoxy oxygen to provide the epoxonium intermediate after initiation of the epoxy or other groups such as, for example, acid labile protecting groups. . However, after this initiation stage, the reaction continues through oxygen attack of the neutral epoxy groups on the epoxide onium intermediate. Growth, polymerization and/or cross-linking then continue until terminated. In these photopatterning processes, controlling polymerization and/or cross-linking becomes important to prevent line growth or sharpening and polymer growth in undesirable areas. Such undesirable characteristics of traditional photopatterning processes include line edge roughness, line wiggle, and other less than ideal pattern geometries. These features are particularly critical in lines and spaces smaller than 20 nm. Therefore, any method that will control polymerization and/or cross-linking in photosystems to produce less undesirable geometries, such as during EUV exposure for example, is highly desirable.

without

As used herein, the conjunction "and" is intended to be inclusive and the conjunction "or" is not intended to be exclusive unless the context indicates or requires otherwise. For example, the phrase "or, alternatively" is intended to be exclusive. As used herein, the term "exemplary" is intended to describe an example and to indicate a preference. As used herein, the term "energetically available" is used to describe a product that is thermodynamically or kinetically available via a chemical reaction.

As used herein, the terms "have," "contains," "includes," "includes," and similar terms are open-ended terms that indicate the presence of stated elements or characteristics but do not exclude other elements or characteristics. The articles "a", "an" and "the" are intended to include the plural as well as the singular unless the context clearly indicates otherwise.

We were surprised to find that adding certain stable dipole materials to positive or negative resists improves the geometry and integrity of lines and spaces after EUV exposure and processing, such as improving line edge roughness, line Twist, overcut, bridging, line collapse, etc.

As used herein, the term "dipole" means a molecule that contains both positive and negative charge centers on the same molecule, either alpha or further separated from each other in the molecule. Also as used herein, the term "dipole" refers to the following zwitterions, betaines, dipoles, and mesoionic compounds, and does not refer to any one specific molecule, but rather to representative molecules of the group.

Zwitterions, also known as internal salts, are molecules containing equal numbers of positively and negatively charged functional groups. Amino acids are an example where a chemical equilibrium exists between the parent molecule and the zwitterion.

Disclosed and claimed herein are photolithographic compositions containing the zwitterionic compound (I) shown below.

As mentioned above, the use of base quenchers has been used in positive processing systems where initiation and growth rely on light-generated acids. In the negative working system of the present invention, the photogenerated acid functions to initiate the curing process, and further polymerization and/or cross-linking is independent of the acid. As such, base quenchers have only a very limited role in current systems.

We have discovered a group of materials that act as "molecular switches."

Without being bound by theory, it is believed that the zwitterionic compounds of the present invention interfere with the stray growth of polymerization in negative photoresists, resulting in improved structural integrity of the desired resist geometry; and in positive photoresists, it is believed that this The inventive zwitterionic compounds interfere with unrelated deprotection processes to prevent developer attack. These stable anions, when used as acid quenchers, become protonated species with a pKa of about 13. Therefore, they are about 2 orders of magnitude less acidic than typical protonated secondary amines, or about 100 times less acidic.

Again, without being bound by theory, it is believed that the zwitterionic materials of the present invention act as acid buffers in high light/radiant intensity regions. As used herein, the term buffering refers to the interaction of betaine or dipole additives with light-generated acids.

In extreme ultraviolet-based exposures, in which many H+ atoms are produced (via photoelectrons), this buffering appears to improve the structure, clarity, and integrity of lithographically created patterns.

In areas of high exposure, it is believed that the zwitterionic materials of the photoresist components of the present invention react with high levels of light-generated acid and then the polymerizing and/or crosslinking components of the photoresist react, in this example, It is an epoxy resin component.

In low-exposure areas or areas with acid migration where low levels of light-generated acid occur, the zwitterionic materials of the present composition act as quenchers to stop polymerization and/or cross-linking and prevent migration to unexposed areas, while preventing undesired light pattern structures (Figure 3).

Studies have shown that the zwitterionic materials of the present invention, as components of the photoresists of the present invention, especially in EUV resists, increase contrast and reduce LER due to their quenching properties. It is believed that the zwitterionic materials of the present invention act as chain transfer agents during the polymerization of the photosensitive composition. Furthermore, it is believed that the zwitterionic materials of the present invention act as quenchers that prevent polymerization of the photosensitive composition from migrating into unexposed areas.

In the high light intensity region, the zwitterionic material of the present invention has been used as a buffer and can no longer be used as a quencher. Where a zwitterionic material of the present disclosure has been used as a buffer, propagation or chain transfer (polymerization mechanism) will proceed as desired. The zwitterionic materials of the present invention serve as very effective molecular switches.

In the present invention, other additives are contemplated as molecular switches where exposure of the switch to actinic radiation induces changes in the molecule's configuration, electronic structure, or other properties that may allow buffering, chain growth, and termination.

In various aspects of the invention, it is contemplated as an additive to the zwitterionic synthesis component (Synthon). When these synthetic components present in a lithographic formulation are exposed to radiation such as, for example, I-line or EUV, they become zwitterionic ions that can be used as buffers, chain extenders, chain transfer agents, and/or molecular switches. .

Disclosed and claimed herein is a composition of matter comprising an ester, wherein the ester is a chemical reaction between a malonate ester and an imidamide in the presence of a suitable halogen donor or pseudohalogen donor. product of the reaction. Malonate _{iminamide wherein} Substituted alkyl chain of 1-24 carbon atoms; substituted or unsubstituted phenyl, heteroaryl, or fused aryl or fused heteroaryl, or a combination of both.

This article further discloses the composition of substances produced by the above chemical reaction, wherein R ₁ and R ₂ are combined by chemical bonds to form a ring structure with 5-8 members, and wherein R ₃ and R ₄ are combined by chemical bonds to form a ring structure with 5-8 members. 8-member ring structure.

This article further discloses a composition of a substance, wherein the iminamide contains a fused ring structure as shown below: where m=1-4 and n=1-4.

Further disclosed herein are compositions of matter comprising a solvent; and an ester having chemical structure (I): .

_Wherein X and _Y are the same or different, where An alkyl chain of atoms; a substituted or unsubstituted phenyl, heteroaryl, or fused aryl or fused heteroaryl, or a combination of both.

Further disclosed herein is a composition of matter comprising: a solvent; and an ester having a chemical structure selected from (XII), .

_Wherein X and _Y are the same or different, where An alkyl chain of atoms; a substituted or unsubstituted phenyl, heteroaryl, or fused aryl or fused heteroaryl, or a combination of both.

Within the structures disclosed above, it is also contemplated that tautomers and other resonance structures may also be energetically accessible. Accordingly, the structures disclosed above are intended to include tautomers and other resonance structures. For example: .

_Wherein X and _Y are the same or different, where An alkyl chain of atoms; a substituted or unsubstituted phenyl, heteroaryl, or fused aryl or fused heteroaryl, or a combination of both.

Additionally, X and Y may include, for example, but not limitation, no extended chain, or include -alkyl-, -aryl-, -alkyl-aryl-, -aryl-alkyl-, -alkoxy A divalent extended chain of -, -alkoxy-aryl-, -aryl-alkoxy-, -alkyl-alkoxy-, -alkoxy-alkyl- or a combination of the foregoing.

More specifically, the above-mentioned -alkyl- groups may be branched or unbranched divalent alkyl chains of 1 to 16 carbons with or without heteroatoms substituted in the chain, such as, for example, -CH ₂ -, -CH ₂ CH ₂ -, -CH(CH ₃ )CH ₂ -, -CH ₂ CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ CH ₂ -, butyl isomers, and up to and including hexadecyl Higher analogs of alkyl groups, as well as their isomers. As used herein, -alkyl- also includes any unsaturation in the chain, such as an alkenyl group, such as, for example, -CH=CH-, or an alkynyl group. As mentioned above, -alkyl- groups may have substituted heteroatoms in the chain as part of the chain, such as O, N, S, S=O or _SO2 , etc., such as, for example, -( _{CH2CH2 -} O ) _z -, where z is between about 1 and about 16, or -(CH ₂ CH ₂ NH) _w -, where w is between about 1 and about 16, etc. According to the above, the group, -alkoxy-, may contain one or more branched or unbranched alkyl groups, such as -ethoxy-, -propoxy- or -isopropoxy- groups, with oxygen Atoms separated. Also included are branched alkyl groups containing heteroatoms in the ring, such as, for example, -(CH ₂ CH ₂ NR") _v -, where R" may be R" with or without heteroatoms substituted therein A branched or unbranched divalent alkyl chain having 1 to 16 carbon atoms.

The above-mentioned -aryl- is a substituted or unsubstituted divalent aromatic group. Such aromatic groups include, for example, phenylene (-C ₆ H ₄ -), condensed divalent aromatic groups, such as For example, naphthylene (-C ₁₀ H ₆ -), anthracenyl (-C ₁₄ H ₈ -), etc., and heteroaryl groups such as, for example, nitrogen heterocycles: pyridine, quinoline, pyrrole, indole, pyrrole Azoles, triazines and other nitrogen-containing aromatic heterocycles well known in the art, as well as oxygen heterocycles: Furans, oxazoles and other oxygen-containing aromatic heterocycles, and sulfur-containing aromatic heterocycles such as, for example, thiophene.

Photoresist materials include ester materials, such as (I)-(II), which replace at least a portion of the resin in conventional photoresists, and include photoacid generators. The discussion below describes useful photoacid generators for this purpose.

The composition of the above substances may further include mixing with a photoacid generator. Without limitation, these may include onium salt compounds such as sulfonium salts, phosphonium salts, or phosphonium salts; styrene imine compounds; halogen-containing compounds, styrene compounds, ester sulfonate compounds; quinone diazide Compounds; diazomethane compounds; dimethyl imine sulfonate, ylideneaminooxy sulfonic acid esters; sulfanyldiazomethane, or mixtures thereof and other photoacids well known in the art Generating agent.

Negative working materials also contain cross-linking agents. Cross-linking agents suitable for use in the present invention include compounds which, upon deprotection, are capable of cross-linking with the esters disclosed above, but in any case if either X or Y contains a functional group reactive with the cross-linking agent. These reactive functional groups are alcohols, phenols, protonamides, carboxylic acids, etc. Before the deprotection reaction occurs, at least part of the reactive functional groups are protected by the above-mentioned acid-labile groups. Once the deprotection reaction occurs, the cross-linking agent can react with the deprotected functional group. Without wishing to be bound by theory, it is believed that the photogenerated acid not only reacts with the acid-labile groups of the esters disclosed above, but also facilitates the reaction of the cross-linker with itself and the ester. Examples of cross-linking agents include compounds containing at least one type of substituent group that is cross-linking reactive with phenolic or similar groups on the deprotected ester. Specific examples of this cross-linking group include but are not limited to polymerizable, oligomeric and monomeric materials, which contain epoxy group, glycidyl ether group, oxycyclobutane, glycidyl ester, glycidylamine group, methyl group, etc. Oxymethyl, ethoxymethyl, benzyloxymethyl, dimethylaminomethyl, diethylaminomethyl, dihydroxymethylaminomethyl, dihydroxyethylaminomethyl , morpholinylmethyl, acetyloxymethyl, benzyloxymethyl, formyl, acetyl, vinyl, and isopropenyl.

Non-limiting examples of compounds having the aforementioned cross-linking substituents include bisphenol A-based epoxy compounds, bisphenol F-based epoxy compounds, bisphenol S-based epoxy compounds, novolak resin-based epoxy compounds, and sol-formaldehyde resin-based epoxy compounds. Epoxy compound, poly(hydroxystyrene)-based epoxy compound, (3-ethyloxycyclobutane-3-yl)methanol, 1,3-bis(((3-ethyloxycyclobutane-3-yl) methyl)methoxy)methyl)benzene, 3,3'-oxybis(methylene)bis(3-ethyloxycyclobutane), and phenol novolak oxetane, Sold by Toagosei America Inc. of West Jefferson, Ohio, as OXT-101, OXT-121, OXT-221 and PNOX1009; hydroxymethyl-containing melamine compounds, hydroxymethyl-containing benzoguanamine compounds, hydroxymethyl-containing benzoguanamine compounds, Methyl urea compounds, hydroxymethyl-containing phenol compounds, alkoxyalkyl-containing melamine compounds, alkoxyalkyl-containing benzoguanamine compounds, alkoxyalkyl-containing urea compounds, alkoxy-containing urea compounds Alkyl phenol compounds, carboxymethyl-containing melamine resins, carboxymethyl-containing benzoguanamine resins, carboxymethyl-containing urea resins, carboxymethyl-containing phenol resins, carboxymethyl-containing melamine compounds, Carboxymethyl-containing benzoguanamine compounds, carboxymethyl-containing urea compounds, carboxymethyl-containing phenol compounds, hydroxymethyl-containing phenol compounds, methoxymethyl-containing melamine compounds, methoxymethyl-containing melamine compounds Methyl phenol compounds, methoxymethyl-containing acetylene urea compounds, methoxymethyl-containing urea compounds, and acetyloxymethyl-containing phenolic compounds. Commercially available methoxymethyl-containing melamine compounds, for example, CYMEL300, CYMEL301, CYMEL303, CYMEL305 (manufactured by Mitsui Cyanamid), commercially available methoxymethyl-containing acetylene urea compounds, for example, CYMEL117 4 (manufactured by Mitsui Cyanamid) ), and commercially available methoxymethyl-containing urea compounds, for example, MX290 (manufactured by Sanwa Chemicals).

The photosensitive composition containing the composition of the above-listed substances may further include a solvent to enable spin coating on semiconductors, other devices in processes, or other workpieces. Suitable solvents include ethers, esters, ether esters, ketones, and ketone esters, more specifically, ethylene glycol monoalkyl ether, diethylene glycol dialkyl ether, propylene glycol monoalkyl ether, propylene glycol dialkyl ether , Alkylphenyl ethers (such as methoxybenzene), acetates, glycolic esters, lactates (such as ethyl lactate, methyl lactate, propyl lactate, butyl lactate), ethylene glycol monoalkyl Ether acetates, propylene glycol monoalkyl ether acetates, alkoxyacetates, (non-)cyclic ketones, acetoacetates, pyruvates and propionates. Specific examples of these solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethyl glycol Glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, methylcellulose acetate, ethylcellulose acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl Ether acetate, propylene glycol monopropyl ether acetate, isopropylene acetate, isopropylene propionate, methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone, 4-heptanone, Ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethoxyethyl acetate, ethyl glycolate, 2-hydroxy-3-methylmethylbutyrate, 3-methyl Oxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3-methoxy Butyl butyrate, ethyl acetate, propyl acetate, butyl acetate, methyl acetyl acetate, ethyl acetate acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, Methyl 3-ethoxypropionate and ethyl 3-ethoxypropionate. The aforementioned solvents may be used independently or as a mixture of two or more types. In addition, at least one type of high boiling point solvent such as benzyl ethyl ether, dihexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, acetone acetone, isophorone (isoholone) may be added. ), hexanoic acid, decanoic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethyl carbonate Add ethyl ester, propyl carbonate and phenylcellulose acetate to the aforementioned solvent. Other suitable solvents include halogen solvents.

Various additives may be added to the photoresist formulation to provide certain desirable properties of the photosensitive composition, such as, for example, acid diffusion control agents to retard acid migration to unexposed areas of the coating; to enhance the properties of the substrate coating; Surfactants and leveling agents; adhesion promoters that enhance the adhesion of the coating to the substrate and sensitizers that enhance the photosensitivity of the photosensitive composition coating during exposure, as well as defoaming agents and degassing agents, and coatings Other materials well known in industry.

In addition to the above-mentioned composition of materials, photoacid generator and solvent, some photoresists may additionally contain one or more selected components or additives. Such components include base quenchers. Suitable base quenchers include, but are not limited to: tetramethylammonium hydroxide, triethanolamine, triisopropylamine, N-methylpyrrolidone, 1,8-diazabicyclo[5.4.0]eleven Carbo-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 7-methyl-1,5,7-triazabicyclo(4.4.0 ) Dec-5-ene, quinuclidine, carboxylates (such as tetramethylammonium acetate, tetramethylammonium lactate, tetramethylammonium propionate), etc.

The photosensitive composition may be coated on a substrate, such as a silicon wafer or wafer coated with any of a variety of semiconductor materials or nitrides such as silicon dioxide, aluminum, alumina, copper, nickel, or others well known in the semiconductor industry. A substrate, or a substrate having an organic film thereon, such as, for example, an underlying anti-reflective film or the like. The photoresist composition is coated by methods such as spin coating, curtain coating, slit coating, dip coating, roller coating, blade coating, ultrasonic coating, steam coating, etc. After coating, the solvent is removed, if applicable, to a level where the coating can be properly exposed, and, if applicable, baked and developed. In some cases, 5% solvent may remain in the coating, while in other cases less than 1% is required. Drying can be performed by hot plate heating, convection heating, infrared heating, etc. The coating is then exposed imagewise or wholesale through markings containing the desired pattern.

Radiation suitable for use in the photosensitive composition includes, for example, ultraviolet (UV), bright line spectrum such as mercury lamp (254 nm), KrF excimer laser (248 nm), and ArF excimer laser (193 nm), F ₂ Excimer laser (157 nm), extreme ultraviolet (EUV) (such as 13.5 nm from plasma discharge and synchrotron light sources), extreme ultraviolet (BEUV) (such as 6.7 nm exposure), X-rays (such as synchrotron radiation) . Ion beam lithography and charged particle rays (such as electron beams) can also be used.

After exposure, the exposed coated substrate may optionally be subjected to a post-exposure bake to enhance the reaction of the photoacid produced, such as, for example, heating from about 30 to about 350° C. for about 10 to about 600 seconds. This can be achieved by hot plate heating, convection heating, infrared heating, etc. Heating can also be performed by a laser heating process, such as CO ₂ laser pulse heating for about 2 to about 5 milliseconds. Two heating processes can be combined in series.

A full-wafer exposure process can be applied after pattern exposure to help further hardening. Results show that whole-wafer exposure reduces or eliminates pattern collapse and reduced line edge roughness after negative photoresist development. For example, a 532 nm continuous wave laser exposes a previously exposed resist for 1-2 seconds, followed by wet development. The flooding process may or may not be followed by a heating step.

The exposed film is then developed using a suitable developer. Such developers include organic solvents as well as aqueous solutions, such as aqueous alkalis known in the art. When an organic solvent is used to remove unexposed areas, the solvent is generally less aggressive than the solvent used to prepare the photoresist composition. Examples of aqueous alkaline developers include, for example, at least one type of alkali compound such as alkali metal hydroxides, ammonia, alkylamines, alkanolamines, heterocyclic amines, tetraalkyl ammonium hydroxides (such as tetramethylhydroxide ammonium oxide), choline, and 1,8-diazabicyclo[5.4.0]-7-undecane, 1,5-diazabicyclo[4.3.0]-5-nonene, at a concentration of approximately 1 to about 10% by weight, such as, for example, about 2 to about 5% by weight. Depending on the desired development characteristics and process parameters, appropriate amounts of water-soluble organic solvents (such as methanol and ethanol) and surfactants can also be added to the alkaline aqueous solution.

After development, a final bake step may be included to further enhance the hardening of the currently exposed and developed pattern. The heating process may be, for example, from about 30 to about 350° C. for about 10 to about 120 seconds and may be completed by hot plate heating, convection heating, infrared heating, or the like.

Example

1) Synthesis example 1:

Add tetrabromomethane (4.05 g, 12.2 mmol) and 3 (2.07 g, 11.0 mmol) to a 500 mL round-bottomed flask. Toluene (240 mL) was added and the mixture was stirred under nitrogen for 1 hour. 1,8-diazabicyclo[S.4.0]undec-7-ene (DBU, 7.3 g, 48.2 mmol) was added dropwise. The reaction mixture was stirred under nitrogen for 18 hours and then filtered. The resulting mixture was purified via a silica column using a gradient of toluene then ethyl acetate and then 20% to 50% isopropanol/ethyl acetate. The product fractions were collected and the solvent was removed to give 72% yield of the final product as a thick reddish brown oil. The product was identified as compound 4 by 1H NMR .

2) Synthesis example 2:

Add tetrabromomethane (4.05 g, 12.2 mmol) and 5 (4.27 g, 11.0 mmol) to a 500 mL round bottom flask. Toluene (240 mL) was added and the mixture was stirred under nitrogen for 1 hour. 1,8-diazabicyclo[S.4.0[undec-7-ene (DBU, 7.3 g, 48.2 mmol)) was added dropwise. The reaction mixture was stirred under nitrogen for 18 hours and then filtered. The resulting mixture was purified via a silica column using a gradient of toluene then ethyl acetate and then 20% to 50% isopropanol/ethyl acetate. Product fractions were collected and the solvent was removed to give 63% yield of the final product as a yellow solid. The product was identified as compound 6 by 1H NMR .

3) Synthesis example 3:

Add tetrabromomethane (4.05 g, 12.2 mmol) and 1 (3.74 g, 11.0 mmol) to a 500 mL round-bottomed flask. Toluene (240 mL) was added and the mixture was stirred under nitrogen for 1 hour. 1,8-diazabicyclo[S.4.0[undec-7-ene (DBU, 7.3 g, 48.2 mmol)) was added dropwise. The reaction mixture was stirred under nitrogen for 18 hours and then filtered. The resulting mixture was purified via a silica column using a gradient of toluene then ethyl acetate and then 20% to 50% isopropanol/ethyl acetate. The product fractions were collected and the solvent was removed to give 75.6% yield of the final product as a thick reddish brown oil. The product was identified as compound 2 by 1H NMR .

4) Preparation Example 1: To 100 mL of ethyl lactate, add 0.128 g of 4 (synthesis example 1 of the above product) and 1.00 g of poly[(0-cresolyl glycidyl ether)-co-formaldehyde] (Mn=1270 ) and 0.461g triphenylsonium hexafluoroantimonate and 0.09g triphenylsonium tosylate, and stir at room temperature for 1 hour to obtain a 15 g./liter solution. The composition was coated on a silicon wafer prepared with a 20nm Optistack AL412 lower layer (the lower layer was rotated at 2000 rpm and baked at 205°C for 30 seconds). The composition was spin-coated onto the primed wafer at 500 rpm for 5 seconds, followed by 1500 rpm for 90 seconds. The coated wafer was then heated on a hot plate at 60°C for 3 minutes to obtain a film approximately 20nm thick. The wafers were imagewise exposed to various increasing doses of electron beam through a mask containing a 44 nm pitch pattern and post-exposed with a 1 minute bake at 60°C. Unexposed areas were removed by a 30 second puddle development in n-butyl acetate, followed by a methyl isobutyl ketone rinse. The results for this formulation are shown in Figure 4.

As can be seen from the SEM and Table 1 below, reduced line width roughness can be obtained by properly exposing each critical dimension.

Table 1 Critical Dimensions (nm) Exposure(mJ) Line width roughness (nm) NA 15.33 NA 9.80 17.12 5.16 12.17 21.54 4.82 13.66 24.12 4.31 15.65 27.01 4.49 17.62 30.26 4.21 18.85 33.89 4.12 NA 37.96 NA 19.06 42.52 3.56 23.30 47.62 4.24 NA 53.33 5.33

5) Preparation Example 2: Add 0.15 g of 6 (above product synthesis example 2 ) and 1.17 g of poly[(0-cresolyl glycidyl ether)-co-formaldehyde] (Mn=1270) to 100 mL of ethyl lactate. ) and 0.54g triphenylsonium hexafluoroantimonate and 0.10g triphenylsonium tosylate, and stir at room temperature for 1 hour to obtain a 17.5 g./liter solution. The composition was coated on a silicon wafer prepared with a 20 nm Optistack AL412 lower layer (the lower layer was rotated at 2000 rpm and baked at 205°C for 30 seconds). The composition was spin-coated onto the primed wafer at 500 rpm for 5 seconds, followed by 2500 rpm for 90 seconds. The coated wafer was then heated on a hot plate at 65°C for 3 minutes to obtain a film approximately 17 nm thick. The wafers were imagewise exposed to various increasing doses of electron beam through a mask containing a 44 nm pitch pattern and post-exposed with a 1 minute bake at 65°C. The unexposed areas were removed by a 60 second puddle development in n-butyl acetate, and the results for this formulation are shown in Figure 5, top and Table 2 below.

Table 2 Critical Dimensions (nm) Exposure(mJ) Line width roughness (nm) NA 38.68 NA NA 43.77 NA NA 48.53 NA 15.49 54.35 5.50 16.49 60.87 7.34 19.50 64.17 6.74 20.46 76.36 5.54 NA 85.52 NA

6) Preparation Example 3: To 100 mL of ethyl lactate, add 0.128 g of 2 (the above product synthesis example 3 ) and 1.00 g of poly[(0-cresolyl glycidyl ether)-co-formaldehyde] (Mn=1270 ) and 0.50g triphenylsonium hexafluoroantimonate and 0.09g triphenylsonium tosylate, and stir at room temperature for 1 hour to obtain a 15.0 g./liter solution. The composition was coated on a silicon wafer prepared with a 20 nm Optistack AL412 lower layer (the lower layer was rotated at 2000 rpm and baked at 205°C for 30 seconds). The composition was spin-coated onto the primed wafer at 500 rpm for 5 seconds, followed by 2500 rpm for 90 seconds. The coated wafer was then heated on a hot plate at 65°C for 3 minutes to obtain a film approximately 16 nm thick. The wafers were imagewise exposed to various increasing doses of electron beam through a mask containing a 44 nm pitch pattern and post-exposed with a 1 minute bake at 65°C. The unexposed areas were removed by a 60 second puddle development in n-butyl acetate and the results for this formulation are shown in the lower part of Figure 5 and Table 3 below.

surface 3 Critical Dimensions (nm) Exposure (mJ) Line width roughness (nm) NA 29.60 NA 10.32 21.95 5.04 14.35 27.54 4.83 15.39 30.84 4.47 17.73 34.54 4.22 14.28 38.68 4.53 21.36 43.33 4.64 21.51 48.53 4.24

without

Figure 1 illustrates the reaction of epoxy resin materials to acids including initiation and propagation. Figure 2 illustrates the zwitterionic portion of the materials disclosed and claimed in this context. Figure 3 illustrates a space in which it is believed that the materials of the present invention are beneficial in obtaining nano-sized lines and photoresist deployed therein with minimal line width roughness. Figure 4 shows an SEM of the geometries and line edge roughness obtainable from the zwitterion-containing photoresists of the present invention. Figure 5 shows an SEM of the geometries and line edge roughness obtainable from photoresists containing other zwitterions of the present invention.

without

Claims (9)

A composition of matter comprising a solvent; and an ester of formula (I), _{Wherein ​} Or unsubstituted phenyl, heteroaryl, or fused aryl or fused heteroaryl, or a combination of both. The composition of matter as claimed in claim 1, further comprising a mixture of one or more photoacid generators, the photoacid generator being selected from the group consisting of strontium salts, iodonium salts, sulfonium salts, halogen-containing compounds, sulfonium compounds, Ester sulfonate compounds, diazomethane compounds, dimethyl imine sulfonate esters, ylideneaminooxy sulfonic acid esters, sulfanyl diazomethane, or mixtures thereof. The composition of matter according to claim 2, further comprising at least one cross-linking agent, wherein the at least one cross-linking agent comprises an acid-sensitive monomer or polymer, and wherein the at least one cross-linking agent comprises at least one of Glycidyl ether, novolak resin glycidyl ether, glycidyl ester, glycidylamine, methoxymethyl, ethoxymethyl, butoxymethyl, benzyloxymethyl, dimethylaminomethyl methyl, diethylaminomethyl, dibutoxymethyl, dihydroxymethylaminomethyl, dihydroxyethylaminomethyl, dibutanolaminemethyl, morpholinomethyl, ethanol Cyloxymethyl, benzyloxymethyl, formyl, acetyl, vinyl or isopropenyl. The composition of matter as described in claim 3, wherein the composition is a substance sensitive to ultraviolet (UV), deep ultraviolet, vacuum ultraviolet, extreme ultraviolet, extreme ultraviolet (BEUV), x-rays, electron beams, and ion beams of photoresist. A composition of matter comprising a solvent; and an ester having a chemical structure selected from (IV): Where m=1-4, n=1-4, and where X and Y are the same or different, and have 0-16 heteroatoms substituted in the chain, branched or unbranched, substituted or unsubstituted Alkyl chain of 1-24 carbon atoms; substituted or unsubstituted phenyl, heteroaryl, fused aryl or fused heteroaryl, or a combination of both. The composition of matter as claimed in claim 5, wherein m=2 and n=3. The composition of matter as claimed in claim 6, further comprising a mixture of one or more photoacid generators, the photoacid generator being selected from the group consisting of strontium salts, iodonium salts, sulfonium salts, halogen-containing compounds, sulfonium compounds, Ester sulfonate compound, diazomethane compound, dimethyl imine sulfonate, imideminoxy sulfonate, sulfanyl diazomethane, or mixtures thereof. The composition of matter according to claim 7, further comprising at least one cross-linking agent, wherein the at least one cross-linking agent comprises an acid-sensitive monomer or polymer, and wherein the at least one cross-linking agent comprises at least one of Glycidyl ether, novolak resin glycidyl ether, glycidyl ester, glycidylamine, methoxymethyl, ethoxymethyl, butoxymethyl, benzyloxymethyl, dimethylaminomethyl methyl, diethylaminomethyl, dibutoxymethyl, dihydroxymethylaminomethyl, dihydroxyethylaminomethyl, dibutanolaminemethyl, morpholinomethyl, ethanol Cyloxymethyl, benzyloxymethyl, formyl, acetyl, vinyl or isopropenyl. The composition of matter according to claim 8, wherein the composition is a photoresist sensitive to ultraviolet (UV), deep ultraviolet, vacuum ultraviolet, extreme ultraviolet, x-ray, electron beam, and ion beam.