Photoresist composition and pattern forming method

Abstract

Disclosed herein is a method comprising forming a radiation-sensitive film on a substrate; wherein the radiation-sensitive film comprises a radiation-sensitive composition comprising a photoacid generator; a quencher; an acid-labile polymer formed from a monomer comprising a vinyl aromatic monomer and a monomer comprising an acid-decomposable group; and a solvent; exposing the radiation-sensitive film to activating radiation in a patterned manner; and contacting the radiation-sensitive film with an alkaline developer to form a resist pattern.

Description

Background Art

[0001] The present invention discloses a photoresist composition and a method for making the same, wherein the photoresist composition is used for pattern formation and chip packaging.

[0002] Mobile devices such as wearable electronic products are becoming smaller, lighter and thinner than similar devices manufactured a few years ago. The microprocessors and memory chips used in these devices are also shrinking in size while the performance capabilities are improving. The manufacture and packaging of these electronic devices play an important role in size reduction. For example, flip chip packaging methods have been used to increase the density of I / O (input / output) connections between devices, especially for microprocessing units (MPUs) and dynamic random access memory (DRAM) semiconductor chips.

[0003] Metal pillar bumps, such as copper pillar bumps, are often used as flip chip interconnects for electronic and optoelectronic packaging, including flip chip packaging of CPU and GPU integrated circuits (chips), laser diodes, and semiconductor optical amplifiers (SOAs). Metal pillar bumps provide beneficial connection resistance, high density connection, metal migration resistance, and heat dissipation characteristics.

[0004] Electroplating is often used to make copper pillar bump arrays. A dry film resist (DFR) is attached to a thin sputtered copper film surface and then a mask pattern with an array of contact holes is made using photolithography. Pillars are then formed in the contact hole pattern on the copper surface by electroplating. The photoresist is then removed and the thin sputtered copper layer previously covered by the resist is removed by etching. I-line (365nm) or broadband lithography has been used to image plating mask patterns.

[0005] Another method of preparing the plating mask pattern is to use a thick photoresist layer, in response to the thicker and narrower column size required for further increasing the I / O density. Chemically amplified photoresists may be a suitable choice for achieving faster sensitivity and improved transparency required for higher resolution patterns. Such resist compositions include polymers with acid-labile groups, photoacid generators (PAGs) and solvents. However, when chemically amplified resists are formed on metal layers such as copper layers, it has been observed that the footing profile problem caused by the presence of photoacid at the interface of the metal surface and the resist.

[0006] Resist compositions containing benzotriazole (BTA), benzimidazole and triazole are known for preventing footing problems (see JP 2004198944 A, WO 2006059392 A and JP 2001249451 A). However, there is still a need for new methods and resist compositions that can provide micromask patterns on metal layers. Summary of the invention

[0007] Disclosed herein is a radiation-sensitive composition comprising a photoacid generator; a quencher having a structure of formula (1):

[0008]

[0009] wherein R3 to R6 may be the same or different and are substituted or unsubstituted alkyl groups having 2 to 10 carbon atoms, and wherein R is a group or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, and wherein R7 is a group having the structure of formula (2):

[0010]

[0011] wherein X is a carbonyl group, an ester group, a carbonate group, an amine group, an amide group, a urea group, a sulfate group, a sulfone group, a sulfoxide group, an N-oxide group, a sulfonate group, a sulfonamide group, or a combination thereof, a substituted or unsubstituted C6 to C 14 Aryl, or C3 to C 12 Heteroaryl, wherein the substituent is halogen, hydroxy, cyano, nitro, C1 to C 12 Alkyl, C1 to C 12 Halogenated alkyl, C1 to C 12 Alkoxy, C3 to C 12 Cycloalkyl, amino, C2-C6 alkanoyl, carboxamido, substituted or unsubstituted C6 to C 14 Aryl, or C3 to C 12 heteroaryl; wherein n is 1 or 2; an acid-labile polymer formed from a monomer comprising a vinyl aromatic monomer and a monomer comprising an acid-decomposable group; and a solvent.

[0012] Also disclosed herein is a method comprising forming a radiation-sensitive composition comprising a photoacid generator; a quencher having a structure of formula (1);

[0013] wherein R3 to R6 may be the same or different and are substituted or unsubstituted alkyl groups having 2 to 10 carbon atoms, and wherein R is a group or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, and wherein R7 is a group having the structure of formula (2):

[0014]

[0015] wherein X is a carbonyl group, an ester group, a carbonate group, an amine group, an amide group, a urea group, a sulfate group, a sulfone group, a sulfoxide group, an N-oxide group, a sulfonate group, a sulfonamide group, or a combination thereof, a substituted or unsubstituted C6 to C 14 Aryl, or C3 to C 12 Heteroaryl, wherein the substituent is halogen, hydroxy, cyano, nitro, C1 to C 12 Alkyl, C1 to C 12 Halogenated alkyl, C1 to C 12 Alkoxy, C3 to C 12 Cycloalkyl, amino, C2-C6 alkanoyl, carboxamido, substituted or unsubstituted C6 to C 14 Aryl, or C3 to C 12 heteroaryl; wherein n is 1 or 2; an acid-labile polymer formed from a monomer comprising a vinyl aromatic monomer and a monomer comprising an acid-decomposable group; and a solvent; exposing the radiation-sensitive film to activating radiation in a patterned manner; and contacting the radiation-sensitive film with an alkaline developer to form a resist pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The results of thermogravimetric / differential thermal analysis of different quenchers are depicted;

[0017] Figure 2 A reaction scheme depicting a proposed mechanism of cantilevered outlines of a model for the cleavage of Norrish-1 by acid generation using a fluorinated naphtalimide photoacid generator;

[0018] Figure 3 Reaction scheme depicting the proposed mechanism of the top rounding profile using TEMPO as a scavenger;

[0019] Figure 4 Depicts E op and CD displacement versus PEB temperature variables;

[0020] Figure 5 It is shown that polymeric plasticizers produce better PED stability as PEB temperature increases; and

[0021] Figure 6 It is shown that the combination of a polymeric plasticizer and a hindered amine (having a Norrish-type cleavage structure) produces a favorable pattern profile both before and after PED. DETAILED DESCRIPTION

[0022] In the present disclosure, "actinic rays" or "radiation" means, for example, the bright line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV light), X-rays, particle rays (such as electron beams and ion beams), etc. In addition, in the present invention, "light" means actinic rays or radiation.

[0023] In addition, unless otherwise specified, "exposure" in this specification includes not only exposure by mercury lamp, far ultraviolet rays represented by excimer laser, X-rays, extreme ultraviolet rays (EUV light), etc., but also writing with particle rays such as electron beams and ion beams.

[0024] In the present specification, “(value) to (value)” means a range including the numerical values ​​described before and after “to” as the lower limit value and the upper limit value, respectively.

[0025] A dash ("-") that is not between two letters or symbols is used to indicate the point of attachment of a substituent. For example, -(CH2)C3-C8cycloalkyl is attached through the carbon of the methylene (CH2) group.

[0026] In the present specification, “(meth)acrylate” means “at least one of acrylate and methacrylate”. Also, “(meth)acrylic acid” means “at least one of acrylic acid and methacrylic acid”.

[0027] As defined herein, "alkanoyl" is an alkyl group covalently bonded to a group substituted with a keto (-(C=O)-) bridge. Alkanoyl groups have the specified number of carbon atoms, wherein the carbon of the keto group is included in the numbered carbon atoms. For example, a C2 alkanoyl group is an acetyl group having the formula CH3(C=O)-.

[0028] As used herein, the term "alkyl" means a branched or straight chain saturated aliphatic hydrocarbon group having a specified number of carbon atoms, typically 1 to about 12 carbon atoms. As used herein, the term C1-C6 alkyl indicates an alkyl group having 1, 2, 3, 4, 5, or 6 carbon atoms. Other embodiments include alkyl groups having 1 to 8 carbon atoms, 1 to 4 carbon atoms, or 1 or 2 carbon atoms, such as C1-C6 alkyl, C1-C4 alkyl, and C1-C2 alkyl. When C0-C6 alkyl is used herein, C1-C6 alkyl refers to an alkyl group having 1 to 8 carbon atoms, 1 to 4 carbon atoms, or 1 or 2 carbon atoms. n When an alkyl group is used in conjunction with another group (e.g., (cycloalkyl)C0-C4alkyl), the group indicated (in this case, the cycloalkyl group) may be directly bonded via a single covalent bond (C0), or attached via an alkyl chain having the specified number of carbon atoms, in this case 1, 2, 3, or 4 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, 3-methylbutyl, tert-butyl, n-pentyl, and sec-pentyl.

[0029] As used herein, the term "cycloalkyl" refers to a saturated hydrocarbon ring radical having only carbon ring atoms and having a specified number of carbon atoms, typically having 3 to about 8 ring carbon atoms or 3 to about 7 carbon atoms. Examples of cycloalkyls include: cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl, as well as bridged or caged saturated ring radicals such as norbornane or adamantane.

[0030] As used herein, the term "heterocycloalkyl" indicates a saturated cyclic group containing 1 to about 3 heteroatoms selected from N, O and S, the remaining ring atoms being carbon. Heterocycloalkyl has 3 to about 8 ring atoms, and more typically has 5 to 7 ring atoms. Examples of heterocycloalkyl include morpholinyl, piperazinyl, piperidinyl, and pyrrolidinyl. The nitrogen in the heterocycloalkyl may be optionally quaternized.

[0031] In the reference to a group and an atomic radical in this specification, when the group is expressed without clearly indicating whether the group is substituted or unsubstituted, the group includes groups and atomic radicals without a substituent, as well as groups and atomic radicals with a substituent. For example, "alkyl" without indicating whether it is substituted or unsubstituted includes not only alkyl groups without a substituent (unsubstituted alkyl) but also alkyl groups with a substituent (substituted alkyl).

[0032] As used herein, the term "alkenyl" means a straight and branched hydrocarbon chain containing one or more unsaturated carbon-carbon bonds, which can occur at any stable point along the chain. The alkenyl described herein typically has 2 to about 12 carbon atoms. Exemplary alkenyls are lower alkenyls, and those alkenyls have 2 to about 8 carbon atoms, such as C2-C8, C2-C6, and C2-C4 alkenyls. Examples of alkenyls include vinyl, propenyl, and butenyl.

[0033] The term "alkynyl" means straight and branched hydrocarbon chains containing one or more C≡C carbon-carbon triple bonds (which can occur at any stable point along the chain). The alkynyl groups described herein typically have 2 to about 12 carbon atoms. Exemplary alkynyl groups are lower alkynyl groups, those alkynyl groups have 2 to about 8 carbon atoms, such as C2-C8, C2-C6, and C2-C4 alkynyl groups. Examples of alkynyl groups include ethynyl, propynyl, and butynyl.

[0034] As used herein, the term "cycloalkenyl" means a saturated hydrocarbon ring group comprising one or more unsaturated carbon-carbon bonds (which can exist at any stable point of the ring) and having a specified number of carbon atoms. Monocyclic cycloalkenyl groups typically have 3 to about 8 carbon ring atoms or 3 to 7 (3, 4, 5, 6 or 7) carbon ring atoms. The cycloalkenyl substituent can be a side group of substituted nitrogen or carbon atoms, or the substituted carbon atoms that can have two substituents can have a cycloalkenyl group attached as a spirocyclic group. Examples of cycloalkenyl groups include cyclopropenyl, cyclobutenyl, cyclopentenyl or cyclohexenyl and bridged or caged saturated ring groups, such as norbornene.

[0035] As used herein, the term "(cycloalkyl)C0-C n "Cycloalkyl" means a substituent wherein cycloalkyl and alkyl are as defined herein and the point of attachment of the (cycloalkyl)alkyl to the molecule it replaces is through a single covalent bond (C0alkyl) or on the alkyl. (Cycloalkyl)alkyl includes, but is not limited to, cyclopropylmethyl, cyclobutylmethyl, and cyclohexylmethyl.

[0036] As used herein, the term "(heterocycloalkyl)C0-C n "Alkyl" means a substituent wherein heterocycloalkyl and alkyl are as defined herein and the point of attachment of the (heterocycloalkyl)alkyl to the molecule it replaces is through a single covalent bond (Coalkyl) or on the alkyl group. (Heterocycloalkyl)alkyl includes, but is not limited to, morpholinylmethyl, piperazinylmethyl, piperidinylmethyl, and pyrrolidinylmethyl.

[0037] As used herein, the term "aryl" means an aromatic group containing only carbon in one or more aromatic rings. Typical aryl groups contain 1-3 independent, fused or side rings and 6 to about 18 ring atoms, without heteroatoms as ring members. When indicated, such aryl groups may be further substituted with carbon or non-carbon atoms or groups. Bicyclic aryl groups may be further substituted with carbon or non-carbon atoms or groups. Bicyclic aryl groups may contain two fused aromatic rings (naphthyl) or aromatic rings fused to 5- to 7-membered non-aromatic ring groups, which optionally contain 1 or 2 heteroatoms independently selected from N, O and S, such as 3,4-methylenedioxy-phenyl. Aryl groups include, for example, phenyl, naphthyl (including 1-naphthyl and 2-naphthyl) and biphenyl.

[0038] As used herein, the term "monocyclic or bicyclic heteroaryl" indicates a stable 5- to 7-membered monocyclic or 7- to 10-membered bicyclic heterocyclic ring containing at least one aromatic ring containing 1 to 4 or particularly 1 to 3 heteroatoms selected from N, O and S, the remaining ring atoms being carbon. When the total number of S and O atoms in the heteroaryl exceeds 1, these heteroatoms are not adjacent to each other. In particular, the total number of S and O atoms in the heteroaryl is not greater than 2, more particularly, the total number of S and O atoms in the heteroaryl is not greater than 1. The nitrogen atom in the heteroaryl may be optionally quaternized. When indicated, such heteroaryl groups may be further substituted with carbon or non-carbon atoms or groups. Such substitution may include fusion with a 5- to 7-membered saturated cyclic group, the saturated cyclic group optionally containing 1 or 2 heteroatoms independently selected from N, O and S to form, for example, [1,3] dioxol [4,5-c] pyridinyl. In certain embodiments, a 5- to 6-membered heteroaryl is used. Examples of heteroaryl include, but are not limited to, pyridyl, indolyl, pyrimidinyl, pyridazinyl, pyrazinyl, imidazolyl, oxazolyl, furanyl, thienyl, thiazolyl, triazolyl, tetrazolyl, isoxazolyl, quinolyl, pyrrolyl, pyrazolyl, benzo[b]thienyl, isoquinolyl, quinazolinyl, quinoxalinyl, thienyl, isoindolyl, and 5,6,7,8-tetrahydroisoquinoline.

[0039] "Haloalkyl" includes branched and straight chain alkyl groups with a specified number of carbon atoms, which are substituted with one or more halogen atoms (up to the maximum allowed number of halogen atoms). Examples of haloalkyl groups include, but are not limited to, trifluoromethyl, difluoromethyl, 2-fluoroethyl, and penta-fluoroethyl.

[0040] "Haloalkoxy" is a haloalkyl group as defined herein attached through an oxygen bridge (the oxygen of the alcohol group).

[0041] "Halo" or "halogen" is any of fluorine, chlorine, bromine, and iodine.

[0042] "Mono- and / or di-alkylamino" is a secondary or tertiary alkylamino group, wherein the alkyl groups are independently selected from alkyl groups as defined herein having the specified number of carbon atoms. The point of attachment of the alkylamino group is on the nitrogen. Examples of mono- and di-alkylamino groups include ethylamino, dimethylamino, and methyl-propyl-amino. Amino means -NH2.

[0043] As used herein, the term "substituted" means that any one or more hydrogens on a designated atom or group are replaced by a selection from a designated group, provided that the normal valence of the designated atom is not exceeded. When the substituent is an oxo (i.e., =O), 2 hydrogens on the atom are replaced. When an oxo group replaces an aromatic moiety, the corresponding partially unsaturated ring replaces the aromatic ring. For example, a pyridyl group substituted with an oxo group is a pyridone. These combinations are allowed only when the combination of substituents and / or variables produces a stable compound or a useful synthetic intermediate. A stable compound or a stable structure is meant to imply a compound that is robust enough to be isolated from a reaction mixture and subsequently formulated into an effective therapeutic agent.

[0044] Unless otherwise indicated, substituents are named to the core structure. For example, it is understood that when (cycloalkyl)alkyl is listed as a possible substituent, the point of attachment of the substituent to the core structure is in the alkyl portion, or when arylalkyl is listed as a possible substituent, the point of attachment to the core structure is the alkyl portion.

[0045] Suitable groups that may be present in a "substituted" or "optionally substituted" position include, but are not limited to, halogen; cyano; hydroxy; nitro; azido; alkanoyl (e.g., C2-C6 alkanoyl, such as acyl, etc.); carboxamido; alkyl (including cycloalkyl) groups having 1 to about 8 carbon atoms or 1 to about 6 carbon atoms; alkenyl and alkynyl groups, including groups having one or more unsaturated bonds and 2 to about 8 or 2 to about 6 carbon atoms; alkoxy groups having one or more oxygen bonds and 1 to about 8 or 1 to about 6 carbon atoms; aryloxy groups, such as phenoxy; alkylthio groups, including those having one or more thioether bonds and 1 to about 8 carbon atoms or 1 to about 6 carbon atoms; alkylsulfinyl groups, including those having one or more sulfinyl bonds and 1 to about 8 carbon atoms or 1 to about 6 carbon atoms; alkylsulfonyl groups, including those having one or more sulfonyl bonds and 1 to about 8 carbon atoms or 1 to about 6 carbon atoms; aminoalkyl groups, including those having one or more N atoms and 1 to about 8 or 1 aryl groups having 6 or more carbon atoms and one or more rings (e.g., phenyl, biphenyl, naphthyl, etc., each ring being substituted or unsubstituted aromatic); arylalkyl groups having 1 to 3 separate or fused rings and 6 to about 18 ring carbon atoms, wherein benzyl is an exemplary arylalkyl group; arylalkoxy groups having 1 to 3 separate or fused rings and 6 to about 18 ring carbon atoms, wherein benzyl is an exemplary arylalkoxy group; or arylalkyl groups having 1 to 3 separate or fused rings and 6 to about 18 ring carbon atoms, wherein benzyl is an exemplary arylalkoxy group. The saturated, unsaturated or aromatic heterocyclic radical of independent or fused ring, each ring has 3 to about 8 members and has one or more N, O or S atoms, for example, coumarinyl, quinolyl, isoquinolyl, quinazolinyl, pyridyl, pyrazinyl, pyrimidinyl, furanyl, pyrrolyl, thienyl, thiazolyl, triazinyl, oxazolyl, isoxazolyl, imidazolyl, indolyl, benzofuranyl, benzothiazolyl, tetrahydrofuranyl, tetrahydropyranyl, piperidinyl, morpholinyl, piperazinyl, and pyrrolidinyl. Such heterocyclic radicals can be further substituted by, for example, hydroxyl, alkyl, alkoxy, halogen and amino.

[0046] Disclosed herein is a radiation-sensitive composition comprising a quencher; a photoacid generator; an acid-labile polymer; an optional adhesion promoter; an optional aromatic azole compound; and a solvent. The radiation-sensitive composition is advantageous because it can be used to make a radiation-sensitive film. The radiation-sensitive film can be soft-baked to minimize the solvent content in the film, thereby forming a non-sticky coating and improving the adhesion of the film to the substrate. The radiation-sensitive film is then exposed using radiation such as ultraviolet light (having a wavelength of 200 to 500 nanometers (nm)) or visible light through a mask (having a predetermined pattern disposed thereon). Preferably, the exposure is performed with radiation having a wavelength of 365 nm (i-line).

[0047] In an embodiment, the quencher has a structure of formula (1):

[0048]

[0049] wherein R3 to R6 may be the same or different and are substituted or unsubstituted alkyl groups having 2 to 10 carbon atoms, and wherein R is a group having 1 to 10 carbon atoms or a substituted or unsubstituted alkyl group, wherein R7 is hydrogen or a group having the structure of formula (2):

[0050]

[0051] wherein X is a nitrogen atom, a sulfur atom, a phosphorus atom, a halogen atom, a carbonyl group, an ester group, a carbonate group, an amine group, an amide group, a urea group, a sulfate group, a sulfone group, a sulfoxide group, an N-oxide group, a sulfonate group, a sulfonamide group, a substituted or unsubstituted C6 to C 14 Aryl, or C3 to C 12 Heteroaryl, wherein the substituent is halogen, hydroxy, cyano, nitro, C1 to C 12 Alkyl, C1 to C 12 Halogenated alkyl, C1 to C 12 Alkoxy, C3 to C 12 Cycloalkyl, amino, C2-C6 alkanoyl, carboxamido, substituted or unsubstituted C6 to C 14 Aryl, or C3 to C 12 wherein n is 1 or 2. A suitable halogen atom is fluorine. In an embodiment, R in structure (1) is not hydrogen. In another embodiment, R3 to R7 are neither amine nor amino.

[0052] In a preferred embodiment, the quencher having structure (2) has a structure of formula (3):

[0053]

[0054] wherein R8 is a substituted or unsubstituted aryl group, a condensed aryl group, or a substituted or unsubstituted monovalent or divalent alkyl group having 6 to 20 carbon atoms. In the structure of formula (3), n is 1 or 2.

[0055] In another preferred embodiment, the quencher may have structures (4) to (6):

[0056]

[0057] and

[0058] The amount of quencher in the radiation-sensitive composition is designed based on the number of moles of the photoacid generator. For example, based on the weight of the polymer, when 4H-TEMPO is selected as the quencher and the radiation-sensitive composition has a low solid content (e.g., less than 20 wt% solids) and a low photoacid generator loading rate of less than 1 wt%, the quencher loading rate is maintained at up to 0.0001 wt%. Based on the total weight of the radiation-sensitive composition, when TINUVIN-123 is selected to have a large solid content (e.g., 50 wt% or more solids) and a high photoacid generator (e.g., NHNI-PFBS) loading rate of 3 wt% or more, the quencher loading rate can be up to 1.2 wt%.

[0059] In an embodiment, the molar ratio percentage of the quencher to the photoacid generator (expressed as a percentage) is 5% to 50%, preferably 8% to 30%, and most preferably 10% to 15%.

[0060] The quencher of structures (1) to (6) can be used in the radiation-sensitive composition in an amount of 0.0001 wt % to 1.2 wt % based on the total weight of the radiation-sensitive composition. In a preferred embodiment, the quencher of structures (1) to (6) can be used in the radiation-sensitive composition in an amount of 0.001 wt % to 0.8 wt % based on the total weight of the radiation-sensitive composition.

[0061] The radiation-sensitive composition includes a photoacid generator (PAG). It is desirable to use a photoacid generator that generates photoacid by Norrish-1 cleavage. The Norrish-I reaction is a photochemical cleavage or homolysis of aldehydes and ketones into two free radical intermediates. The carbonyl group receives a photon and is excited to a photochemical singlet state. In an embodiment, the photoacid generator has the structure shown in formula (7):

[0062]

[0063] In formula (7), R7 is a hydrogen atom, a substituted or unsubstituted straight or branched C1 to C 14 alkyl, a substituted heterocyclic group, or a halogen atom; and wherein R8 is a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, a halogen atom, or an aryl group having 6 to 20 unsubstituted carbon atoms.

[0064] Examples of suitable photoacid generators are N-hydroxynaphthalene dicarboxylic acid imide trifluoromethanesulfonate, N-hydroxynaphthalene dicarboxylic acid imide perfluoro-1-butanesulfonate, N-hydroxynaphthalene dicarboxylic acid imide camphor-10-sulfonate, N-hydroxynaphthalene dicarboxylic acid imide 2-trifluoromethylphenylsulfonate, N-hydroxy-5-norbornene-2,3-dicarboxylic acid imide perfluoro-1-butanesulfonate, N-(trifluoromethanesulfonyloxy)phthalimide or N-hydroxysuccinimide perfluorobutanesulfonate. In a preferred embodiment, the photoacid generator is fluoroolefinsulfonyloxy-1,8-naphthalene dicarboxylic acid imide.

[0065] Photoacid generators may also include those suitable for the purpose of preparing photoresists.Such photoacid generators may include, for example, nonionic oximes.

[0066] The photoacid generator is present in the radiation-sensitive composition in an amount of 0.25 parts by weight or greater, 0.5 parts by weight or greater, and preferably 0.75 parts by weight or greater to a maximum of 10 parts by weight per 100 parts by weight of the acid-labile polymer.

[0067] In an embodiment, the photoacid generator may be present in the radiation-sensitive composition in an amount of 0.3 wt % or greater, preferably 0.4 wt % or greater to a maximum of 5 wt % based on the total weight of the radiation-sensitive composition.

[0068] The radiation-sensitive composition further comprises a copolymer, the copolymer being formed by a first repeating unit containing an acid-decomposable group and a second repeating unit containing a vinyl aromatic monomer. The polymer is also referred to as an acid-labile polymer. In an embodiment, the first repeating unit having an acid-labile group has a structure represented by formula (8):

[0069] Wherein R9 is hydrogen or an alkyl group having 1 to 10 carbon atoms and wherein L comprises a carbonyl group (e.g., species including aldehydes; ketones; carboxylic acids and carboxylates, such as, for example, (meth)acrylic acid and (meth)acrylate), a single bond (e.g., vinyl ether) or an aromatic unit (e.g., styrene or a derivative thereof). In an embodiment, the carboxylate is a tertiary alkyl ester.

[0070] In an embodiment, when L contains a carbonyl group, the repeating unit containing an acid-labile group has a structure represented by the following formula (9):

[0071] Where R 10 is hydrogen or an alkyl or halogenated alkyl group having 1 to 10 carbon atoms and wherein R 11It is a straight or branched substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group or a tertiary alkyl ester having 3 to 14 carbon atoms. The cycloalkyl group may contain one or more heteroatoms, such as oxygen, sulfur, nitrogen or phosphorus. Combinations of heteroatoms may also be used. For example, the cycloalkyl group may contain oxygen and nitrogen heteroatoms. Repeating units having the structure of formula (9) without an acid-labile group may also be used in the resist polymer, as long as the resist polymer has at least one repeating unit having an acid-labile group.

[0072] Examples of other monomers containing acid labile groups (eg, carbonyl groups) are shown below in formula (10):

[0073] Where R 12 is hydrogen or an alkyl or halogenated alkyl group having 1 to 10 carbon atoms, and wherein R 13 , R 14 and R 15 R may be the same or different and is selected from a linear or branched substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 14 carbon atoms, an aryl group or a heteroaryl group. The cycloalkyl group may contain one or more heteroatoms such as oxygen, sulfur, nitrogen or phosphorus. Combinations of heteroatoms may also be used. For example, the cycloalkyl group may contain oxygen and nitrogen heteroatoms. In an embodiment, R 13 , R 14 or R 15 May contain cyclic portions.

[0074] In the embodiment, R in formula (10) 13 , R 14 and R 15 The alkyl radicals may be the same or different and contain hydrogen, substituted or unsubstituted alkyl radicals having 2 to 8 carbon atoms which may be straight chain or branched, or substituted or unsubstituted cycloalkyl radicals having 4, 5 or 6 carbon atoms which may contain branches.

[0075] Examples of monomers containing a carbonyl acid labile group include:

[0076]

[0077]

[0078] or a combination thereof; wherein R1 is hydrogen or an alkyl group having 1 to 10 carbon atoms, a halogen, or a haloalkyl group having 1 to 10 carbon atoms, and wherein R 16 is an alkyl group including a branched structure having 1 to 10 carbon atoms or a monocyclic or polycyclic cycloalkyl group having 3 to 14 carbon atoms; and R 17The alkyl group may include a branched structure having 1 to 10 carbon atoms or a monocyclic or polycyclic cycloalkyl group having 3 to 14 carbon atoms. The preferred halogen atom is a fluorine atom, and the preferred halogenated alkyl group includes a fluoroalkyl group.

[0079] In an embodiment, when L in formula (8) contains more than one carbon atom, the repeating unit containing an acid-labile group has a structure represented by the following formula (11):

[0080]

[0081] wherein Z is a linking unit comprising at least one carbon atom and at least one heteroatom, wherein R 18 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; and wherein R 19 It may be an alkyl group having a branched structure of 1 to 10 carbon atoms or a monocyclic or polycyclic cycloalkyl or tertiary alkyl ester having 3 to 14 carbon atoms. In an embodiment, Z may have 2 to 10 carbon atoms. In another embodiment, Z may be CH2-C(=O)-O-.

[0082] Specific examples of repeating units having the structure of formula (11) are as follows:

[0083]

[0084] Illustrative acid labile acetal and ketal substituted monomers also include:

[0085]

[0086]

[0087] and their combinations, where R a is -H, -F, -CH3 or -CF3 and wherein R1 is hydrogen or alkyl having 1 to 10 carbon atoms, halogen, or haloalkyl having 1 to 10 carbon atoms.

[0088] In another embodiment, when L (in formula (8) shown above) is an aromatic unit, the acid labile repeating unit may be a vinyl aromatic unit having the structure of formula (12):

[0089] Where R 20 is hydrogen, alkyl or halogen; Z1 is hydroxy or optionally hydrogen, halogen, alkyl, aryl, or fused aryl; and p is 1 to about 5. In an embodiment, Z1 is preferably hydroxy.

[0090] Vinyl aromatic monomers that can react to form resist polymers include styrene, alkyl styrene, hydroxy styrene, or styrene substituted with halogen. Examples of suitable alkyl styrenes are o-methyl styrene, p-methyl styrene, m-methyl styrene, α-methyl styrene, o-ethyl styrene, m-ethyl styrene, p-ethyl styrene, α-methyl-p-methyl styrene, 2,4-dimethyl styrene, p-tert-butyl styrene, 4-tert-butyl styrene, etc. or combinations thereof. Examples of styrenes substituted with halogen include chlorostyrene, fluorostyrene, hydroxy fluorostyrene, or combinations thereof.

[0091] In a preferred embodiment, the acid-labile repeating unit has a tertiary carbon as an acid-labile group (e.g., tert-butyl acrylate or tert-butyl methacrylate). In another preferred embodiment, the vinyl aromatic monomer is 4-hydroxystyrene. In other words, the acid-labile polymer comprises a copolymer of hydroxystyrene and a (meth)acrylic monomer comprising a tertiary carbon as an acid-labile species, wherein the copolymer has a weight average molecular weight of 10,000 to 30,000 g / mol. Molecular weights are measured using polystyrene standards.

[0092] In yet another embodiment, the acid labile polymer may contain a third repeating unit such as a second vinyl aromatic monomer (e.g., styrene) in addition to the repeating units containing the first vinyl aromatic monomer (e.g., 4-hydroxystyrene) and the repeating units containing the acid labile group. In a preferred embodiment, the vinyl aromatic monomer comprises a polyhydroxystyrene monomer. In another preferred embodiment, the vinyl aromatic monomer comprises both styrene and polyhydroxystyrene monomers.

[0093] The vinyl aromatic polymer may be present in the acid labile polymer in an amount of 40 to 90 mol%, preferably 60 to 87 mol%, based on the total moles of the acid labile polymer.

[0094] The acid-labile repeating unit may be present in an amount of 5 to 70 mol%, preferably 10 to 50 mol%, and more preferably 15 to 40 mol%, based on the total moles of the acid-labile polymer (i.e., copolymer). The acid-labile polymer is present in the radiation-sensitive composition in an amount of 10 to 98 wt% based on the total weight of the radiation-sensitive composition. In a preferred embodiment, the acid-labile polymer may be used in the radiation-sensitive composition in an amount of 30 to 55 wt% based on the total weight of the radiation-sensitive composition.

[0095] In an embodiment, when the acid-labile polymer contains repeating units of polyhydroxystyrene and tert-butyl acrylate, the polyhydroxystyrene is present in an amount of 60 to 66 mol % based on the total moles of the acid-labile polymer. In an embodiment, tert-butyl acrylate is present in an amount of 34 to 40 mol % based on the total moles of the acid-labile polymer.

[0096] In another embodiment, when the acid-labile polymer contains repeating units of polyhydroxystyrene, styrene, and tert-butyl acrylate, the polyhydroxystyrene is present in an amount of 60 to 66 mol%, preferably 62 to 65 mol%, based on the total moles of the acid-labile polymer. In another embodiment, styrene is present in an amount of 15 to 22 mol%, preferably 18 to 20 mol%, based on the total moles of the acid-labile polymer. In another embodiment, tert-butyl acrylate is present in an amount of 12 to 20 mol%, preferably 13 to 17 mol%, based on the total moles of the acid-labile polymer.

[0097] As noted above, the radiation-sensitive composition contains a solvent. The solvent is used to solvate the polymer used in the composition and promote the miscibility of the various ingredients used in the composition. In certain embodiments, the radiation-sensitive composition in the solution comprises a polymer in an amount of 40 to 90 wt%, particularly 50 to 85 wt%, more particularly 55 to 80 wt% based on the weight of the total solids. It will be understood that the "polymer" used in this context of the component in the resist can only mean a copolymer disclosed herein, or a combination of a copolymer and another polymer useful in a photoresist. It will be understood that the total solid includes a polymer, a light-destructible base, a quencher, a surfactant, any added PAGs, and any optional additives (excluding solvents).

[0098] Solvents generally suitable for dissolving, dispensing and coating include anisole, alcohols (including 1-methoxy-2-propanol (also known as propylene glycol methyl ether, PGME) and 1-ethoxy-2-propanol), esters (including n-butyl acetate, 1-methoxy-2-propyl acetate (also known as propylene glycol methyl ether acetate, PGMEA), methoxyethyl propionate, ethoxyethyl propionate and gamma-butyrolactone), ketones (including cyclohexanone, 2,6-dimethyl-4-heptanone, 2-heptanone), ethyl lactate (EL), methyl 2-hydroxyisobutyrate (HBM), gamma-butyrolactone (GBL), methyl 3-methoxypropionate, and combinations thereof.

[0099] The amount of the solvent may be, for example, 40 to 90 wt %, preferably 45 to 65 wt %, and more preferably 48 to 58 wt % based on the total weight of the radiation-sensitive composition.

[0100] The radiation-sensitive composition may contain other optional ingredients, such as one or more surface leveling agents (SLAs), polymeric adhesion promoters and / or plasticizers.

[0101] If used, the SLA is preferably present in an amount of 0.001 to 0.1 wt % based on the total solids of the composition, and the adhesion promoter and / or plasticizer are each present in an amount of 0.1 to 10 wt % based on the total solids of the composition.

[0102] In an embodiment, the polymer adhesion promoter is obtained by polymerization of a monomer having a structure of formula (13)

[0103]

[0104] Where R 21 is a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms. In a preferred embodiment, R in formula (13) 21 is methyl or ethyl. In an embodiment, the polymer adhesion promoter may have a weight average molecular weight of 30,000 g / mol or more, preferably 50,000 g / mol or more, and more preferably 70,000 g / mol or more. The polymer adhesion promoter may have an upper limit weight average molecular weight of 100,000 g / mol or less, preferably 90,000 g / mol or less.

[0105] The polymer adhesion promoter can be used in an amount of 0.5 parts by weight or more, 0.75 parts by weight or more, and more preferably 0.85 parts by weight or more to a maximum of 20 parts by weight based on 100 parts by weight of the acid-labile polymer. In a preferred embodiment, the polymer adhesion promoter can be used in an amount of 0.5 parts by weight or more to 1.5 parts by weight or less based on 100 parts by weight of the acid-labile polymer.

[0106] In an embodiment, the polymeric adhesion promoter may be used in an amount of 0.25 wt % or more, 0.4 wt % or more to 10 wt % or less, preferably 2 wt % or less, based on the total weight of the radiation-sensitive composition.

[0107] In an embodiment, the radiation-sensitive composition may contain a species having a chelating functional group. In an embodiment, the radiation-sensitive composition may contain an aromatic azole compound, such as a benzotriazole derivative having the structure of formula (14) shown below.

[0108]

[0109] Where R 22 is an alkyl group having 1 to 14 carbon atoms or an amine group.

[0110] The aromatic azole compound may be present in the radiation-sensitive composition in an amount of 0.01 to 10 parts by weight, preferably 0.015 to 1 part by weight, based on 100 parts by weight of the acid-labile copolymer in the radiation-sensitive composition.

[0111] In an embodiment, the azole compound may be used in an amount of 0.001 to 0.5 wt % based on the total weight of the radiation-sensitive composition. In a preferred embodiment, the azole compound may be used in an amount of 0.01 to 0.25 wt % based on the total weight of the radiation-sensitive composition.

[0112] The method of using the radiation-sensitive composition will now be described. According to the patterning method, a radiation-sensitive film is formed on a substrate by the radiation-sensitive composition as described herein. The composition can be applied to the substrate by spin coating, dip coating, roller coating or other conventional coating techniques. Spin coating is preferred. For spin coating, the solid content of the coating solution can be adjusted to provide a desired film thickness based on the specific coating equipment used, the viscosity of the solution, the speed of the coating tool and the amount of time allowed for spinning.

[0113] The radiation-sensitive film can then be soft-baked to minimize the solvent content in the film, thereby forming a tack-free coating and improving the adhesion of the film to the substrate. The soft bake can be performed on a hot plate or in an oven, with a hot plate being typical.

[0114] The radiation-sensitive film is then exposed to activating radiation in a patterned manner through a photomask to produce a solubility difference between the exposed and unexposed areas. The reference herein to exposing the radiation-sensitive film to radiation that has an activating effect on the film indicates that the radiation is capable of forming a latent image in the film. The photomask has optically transparent areas and optically opaque areas corresponding to the areas to be exposed and unexposed in the resist layer by the activating radiation, respectively. The exposure wavelength is typically below 500 nm, such as 200 to 500 nm or visible light. Preferably, the exposure is carried out with radiation of a wavelength of 365 nm (i-line).

[0115] After exposure of the radiation-sensitive film, a post-exposure bake (PEB) is typically performed to decompose the acid-labile groups by the acid generated by the PAG during the exposure step. The PEB can be performed, for example, on a hot plate or in an oven. A latent image defined by the boundary between polarity-switched and unswitched areas (corresponding to the exposed and unexposed areas, respectively) is thereby formed.

[0116] The radiation-sensitive film is then contacted with an alkaline developer to remove the exposed portions of the film, leaving the unexposed areas to form a resist pattern. The developer is typically an aqueous alkaline developer, such as a quaternary ammonium hydroxide solution, for example, a tetraalkylammonium hydroxide solution, such as 0.26 normal (N) (2.38 wt%) tetramethylammonium hydroxide (TMAH).

[0117] Another aspect of the present invention is a method for depositing metal on a metal layer. The method comprises: (i) forming a radiation-sensitive film on the metal layer; (ii) exposing the radiation-sensitive film to activating radiation in a patterned manner; (iii) a post-exposure baking step to decompose acid-labile groups; (iv) contacting the radiation-sensitive film with an alkaline developer to remove the exposed portions of the radiation-sensitive film; and (v) immersing the metal layer in a metal plating solution and electrodepositing metal on the metal layer in the exposed portions of the radiation-sensitive film. The metal layer is typically formed on a substrate.

[0118] The metal layer can be composed of, for example, copper, silver, aluminum, gold or an alloy thereof. The metal layer may also be referred to as the first metal layer herein. When the metal layer is formed on a substrate, the metal layer may be formed using known methods, such as by chemical vapor deposition (CVD) or physical vapor deposition (PVD) techniques, wherein sputtering and plating are typical. The thickness of the metal layer is typically 10 nm to 1000 nm. Examples of substrates include, but are not limited to, silicon wafers, glass substrates and plastic substrates, such substrates optionally including one or more layers or features formed thereon.

[0119] The radiation-sensitive film is formed by a radiation-sensitive composition as described herein, the radiation-sensitive composition comprising: a quencher; a photoacid generator; an acid-labile polymer; an optional adhesion promoter; an optional aromatic azole compound; and a solvent. The radiation-sensitive composition is applied to the metal layer by known methods (such as spin coating, roller coating or screen printing). In order to form a thick radiation-sensitive film, a radiation-sensitive composition with a high solid content and / or high viscosity is typically required. The solid content of the composition is typically 10 to 60 wt%, preferably 20 to 50 wt%, based on the total weight of the radiation-sensitive composition. By using such a composition, a thick layer of, for example, 10 microns or more, preferably 20 to 120 microns, can be formed.

[0120] After applying the radiation-sensitive composition, a soft bake may be performed to minimize the solvent content in the layer and improve the adhesion of the layer to the substrate. The radiation-sensitive film is then exposed using radiation such as ultraviolet light (having a wavelength of 200 to 500 nanometers (nm)) or visible light through a mask having a predetermined pattern. Preferably, the exposure is performed with radiation having a wavelength of 365 nm (i-line).

[0121] The radiation-sensitive film is contacted with an alkaline developer to develop the exposed portion of the radiation-sensitive film. Examples of alkaline developers include aqueous solutions of tetramethylammonium hydroxide, sodium hydroxide, and potassium hydroxide. The exposed portion may form a pattern, such as a hole (e.g., a contact, a through-hole, or a bump pattern) or a groove (e.g., a line spacing) pattern. Such patterns preferably have a high aspect ratio. As used herein, aspect ratio (AR) is defined as AR=h / d, where h is the photoresist height (i.e., thickness) and d is the spacing in the pattern, such as the hole diameter (e.g., for a contact, a through-hole, or a bump pattern) or the length of the spacing between adjacent lines (e.g., for a groove pattern). Typically, the hole diameter may be 2 to 200 microns, preferably 10 to 50 microns. The aspect ratio is typically 0.1 or greater, 0.5 or greater, 0.1 to 10.0, or 0.5 to 7.0.

[0122] Next, the substrate can be immersed in a metal plating solution to plate metal on the exposed first metal layer in those areas where the radiation-sensitive film has been developed. The developed area of ​​the radiation-sensitive film serves as a mold for metal plating. The metal can be plated, for example, by electroplating. Various types of metal plating solutions known in the art can be used. In addition, two or more different metal layers can be formed, and the layers can be the same or different metal layers. Preferred plated metals include, but are not limited to, copper, nickel, tin, silver, gold, and mixtures and alloys thereof. Suitable metal plating solutions for forming such metals are known in the art and are commercially available from Dow Electronic Materials. The thickness of the plated metal layer is typically 1 to 100 microns, preferably 20 to 50 microns. The plated metal layer thickness can be less than or exceed the thickness of the photoresist layer.

[0123] After metal plating, the remaining radiation-sensitive film can be removed (stripped) from the substrate. Suitable photoresist strippers are commercially available, for example Shipley BPR™ Photo Stripper (Dow Electronic Materials).

[0124] The first metal layer of exposure between the plated metal structures can be removed, for example, by an etch-back method, to electrically isolate each of the plated metal structures. The metal structure obtained can, for example, have a columnar shape, which can be used to provide a metal bump for electrical connection between two components. Advantageously, a metal post with a small diameter and a straight (vertical) sidewall can be formed by the composition and method disclosed herein. Such structures are used for electrical connection in, for example, a small, light and thin device. The width (diameter) of the post can, for example, be 5 to 200 microns, preferably 10 to 50 microns. The height of the post will, for example, depend on the thickness of the radiation-sensitive resin, but a post height of 20 microns or more can be formed.

[0125] The invention will now be illustrated by the following non-limiting examples.

[0126] Examples

[0127] Example 1

[0128] This example was conducted to identify the quencher that produces the least weight loss when heated to an elevated temperature.

[0129] Quenchers such as hindered amine light stabilizers (HALS) are often used to control photoacid generation in fluorinated naphthalimide photoacid generators. Reaction Scheme I shows a proposed mechanism for acid-induced photogeneration in perfluorinated naphthalimides.

[0130]

[0131] The free radical quenching mechanism of HALS produces a different effect compared to conventional amine basic quenchers, as seen in Reaction Scheme II below.

[0132]

[0133] Reaction Scheme II depicts the free radical quenching mechanism of hindered amine light stabilizers (HALS). Hindered amine light stabilizers (HALS) are often used as antioxidants in plastics or coatings. During the heating of the plastic or during the coating manufacturing process, an effective amount of HALS needs to be retained in the matrix to perform its intended function. Lower molecular weight compounds generally degrade at higher temperatures, which reduces physical leaching at higher temperatures. In this application, a photoresist is applied to the coating and subjected to a soft bake curing process at 135°C for 1 to 6 minutes. At this temperature, a portion of the HALS in the composition may evaporate or sublime.

[0134] Sublimation or evaporation (when heated) of hindered amine light stabilizers from photoresists or anti-reflective coatings creates some quality control problems in the manufacture of electronic devices because evaporation or sublimation results in the generation of particulate matter. The severity of this damage caused by sublimation becomes more severe due to film thickness, where thicker films (i.e., 10 to 50 microns) can trap more material due to film thickness. In this section, thermogravimetric loss and decomposition or melting point are measured to select passivating compounds.

[0135] Thermogravimetric loss was measured by thermogravimetric analysis / differential thermal analysis (TGA / DTA). Al2O3 was used as a reference. An open aluminum pan was applied under nitrogen flow. The heating rate was 5°C / min. Table 1 details the test conditions used to show the thermogravimetric analysis / differential thermal analysis.

[0136] Table 1

[0137]

[0138] The quenchers subjected to TGA / DT were 4-methoxy-TMP-1-oxyl radical, 4-hydroxy-TMP and 4-hydroxy-TMP-1-oxyl radical, 4-benzoate-TMP-1-oxyl radical, 4-acetamido-TMP-1-oxyl radical and 123. 123 is a liquid hindered amine light stabilizer (HALS) based on amino-ether functional groups.

[0139] The results of thermogravimetric analysis / differential thermal analysis were Figure 1 4-Methoxy-TMP-1-oxyl, 4-hydroxy-TMP and 4-hydroxy-TMP-1-oxyl showed a weight loss of more than 3% in the TG-DTA test at 135°C. TMP-1-oxyl represents tetramethyl-1-piperidinyloxy. TMP represents tetramethylpiperidine.

[0140] Example 2

[0141] This example was conducted to determine the effect of HALS compounds on the pattern profile. The aforementioned quenchers (i.e., HALS compounds) 4-methoxy-TMP-1-oxyl radical, 4-hydroxy-TMP and 4-hydroxy-TMP-1-oxyl radical, 4-benzoate-TMP-1-oxyl radical, 4-acetamide-TMP-1-oxyl radical and 123 is used as a basic quencher in iCAR photoresist.

[0142] The nomenclature for this example is shown in Table 1a.

[0143] Table 1a

[0144]

[0145] Table 2 shows the formulation (composition) of i-line chemically amplified photoresist (iCAR) samples. HALS analogs are used as alkaline quenchers. The amount of quencher is selected so that the quencher / PAG molar ratio is 0.139. TINUVIN-123 (see Formula 6) contains two parts of a piperidine structure (see Formula 1). Therefore, it is expected that the effect of the compound with Formula 1 (from TINUVIN-123) is twice that of other compounds. Therefore, TINUVIN-123 is tested with half the amount of other alkaline quenchers (the quencher loading rate of TINUVAN-1123 is adjusted to a quencher / PAG molar ratio of 0.069).

[0146] Preparation of Sample #1

[0147] In a 500 ml plastic bottle, 90 g (g) of polymer-A (copolymer of p-hydroxystyrene (PHS) / tert-butyl acrylate (TBA) in a 64 / 36 molar ratio, weight average molecular weight Mw=23,000 g / mol, obtained from Maruzen Petrochemical Co., LTD.) and 10 g of polymer-B (copolymer of PHS / styrene (STY) / TBA in a 66 / 19 / 15 molar ratio, (weight average molecular weight Mw=11,000 g / mol, obtained from DuPont Electronic Polymer) were taken. With respect to 100 parts of the polymer, 1 part (1 g) of NHNI-PFBS (produced by Toyo Gosei Kogyo Co., Ltd.) was added. Co. LTD), Mw = 495.27), 0.048 parts (0.048 g) of 4H-TEMPO (weight average molecular weight Mw: 172.25 g / mol) and 1 part (1 g) of PIONIN ME-400 (obtained from Takemoto Oil and Fat.). With respect to the total 102.048 g of material, 117 g of a solvent mixture consisting of 95% PMGEA (111.2 g) and 5% GBL (5.8 g) was added to adjust the solid content to 46.5 wt%.

[0148] The ingredients used to make sample #1 were mixed on a roller shaker. The molar ratio of quencher (4H-TEMPO) and PAG (NHNI-PFBS) was calculated as follows:

[0149] (0.0489g / 172.25) / (1g / 495.27)=0.139

[0150] Preparation of samples #2 to #5

[0151] Samples #2 to #5 were prepared in the same manner as sample #1 and using the same quencher / photoacid generator molar ratio. The only difference was the type of quencher used (as can be seen in Table 2 below). The quencher loading was adjusted to have the same quencher / PAG molar ratio (0.139) as shown in Example 2.

[0152] Sample #6

[0153] Sample #6 was prepared in the same manner as sample #1, except for the type of quencher and the quencher / PAG molar ratio. The quencher was TINUVIN-123. For this sample, the quencher loading was adjusted to have a quencher / PAG molar ratio of 0.069.

[0154] Table 2

[0155]

[0156] All weights in Table 2 are parts / percent based on 100 parts of polymer A and polymer B, except for solids content which is expressed in weight percent.

[0157] From the obtained data, it is seen that samples #2 and #4 produce cantilever profiles. A cantilever profile is a profile in which the sidewall angle is greater than 90° (degrees). In other words, when the width of the photoresist pattern at the surface and the bottom is compared using a scanning electron microscope cross-sectional image, the width of the surface is narrower than the width of the bottom.

[0158] Other samples provided favorable entrance profiles. The thermogravimetric loss of 4H-TEMPO was better than that of 4H-TEMP and 4-methoxy-TEMPO. TINUVIN-123 also showed no weight loss up to 190°C, but sample #6 showed angled sidewalls. From these test results, it can be concluded that the favorable pattern profile does not depend on the volatility of the basic quencher. For example, regardless of the substitution at the 4-position, except for 4-acetamide-TEMPO, quenchers with a piperidine 1-oxy structure provided favorable profiles. Table 3 shows a comparison of HALS analogs for a 1:1 contact hole at a pattern profile of 25 μm (micrometer).

[0159] Table 3

[0160]

[0161] Without being limited to theory, it is believed that the cantilever profile is generated because during the initial step, the fluorinated naphthalimide photoacid generator is cleaved by incident UV light. The chromophore portion of the intermediate (Chromophore Intermediate-1) is then Figure 2 The ring-opening reaction shown in Figure 1 forms the chromophore intermediate-2.

[0162] The I-line exposure process and the post-exposure baking (PEB) process are carried out under ambient atmosphere. This results in the presence of oxygen at the surface of the photoresist. Oxygen penetrates into the photoresist at the exposed surface. Therefore, the highest oxygen concentration is present at the surface of the photoresist. The depth of oxygen penetration into the photoresist depends on its polymer matrix composition, the solvent system used and / or the process conditions used.

[0163] At the surface, the chromophore intermediate-2 is scavenged by oxygen. The effect is called the oxygen inhibition effect. After the intermediate-2 is scavenged, hydrolysis may not occur. Therefore, the acid intermediate, the perfluoroalkylsulfonyl radical, does not extract hydrogen from the hydrolyzed group. As a result, the concentration of photoacid at the surface is lower than that in the middle or bottom of the photoresist. This results in a narrower cross-sectional width (diameter) at the surface than at the bottom. This mechanism is Figure 2 Shown in. Figure 2 A reaction scheme depicting the proposed mechanism of the cantilevered outline of the model for the cleavage of Norish-1 by acid generation employing a fluorinated naphthalimide photoacid generator.

[0164] When TEMPO radical is used for photoresist, chromophore intermediate-2 is removed by TEMPO radical to form nitroxyl alkyl intermediate (NOR-TEMPO). As discussed above, chromophore intermediate-2 is also removed by oxygen. NOR-TEMPO and oxidized intermediate regenerate TEMPO radical together with proton. In this model, the proton produced is coupled with the acid part of the intermediate to then produce photoacid. It is believed that this reaction occurs when oxygen concentration is high. Therefore, TEMPO radical or TINUVIN-123 (NOR-TEMPO) show a favorable profile.

[0165] In the proposed mechanism, the nitroxyl structure of TEMPO plays an important role. Therefore, 4H-TEMP (4-hydroxy-1,2,2,6,6-pentamethylpiperidine) showed a cantilever profile. However, 4-acetamido-TEMPO (4-acetamido-2,2,6,6-tetramethylpiperidinyl 1-oxyl) with a nitroxyl structure improved the cantilever profile. Figure 3 Depicted is a reaction scheme for the proposed mechanism for top fillet profiling using TEMPO as a scavenger.

[0166] Example 3

[0167] This example was conducted to determine the effect of HALS compounds on PEB sensitivity and PED (Post Exposure Delay) stability. TINUVIN-123 was chosen as an example of a NOR-TEMPO type HALS. Troger base and benzotriazole were used as alkaline references for quenchers. The effect of plasticizers was also studied and compared with samples using different plasticizers or with samples without plasticizers. LUTONAL M40 (weight average molecular weight M w =70,000) as a polymer plasticizer. PIONIN M400 was used as a reference product, which has a lower weight average molecular weight (M w =400).

[0168] Evaluation was performed on 15 micron film thickness samples. (SB = 135°C / 60 sec, FT = 15 μm, PEB = 90, 100 and 110°C / 60 sec, development time = 60 sec stirring). A separate groove pattern of 15 microns (μm) was used for photolithographic comparison. The photoresist was exposed by a broadband exposure tool (MA-1200). A CD-exposure curve was made for each condition. The sizing energy (E) for each sample and condition was determined from the CD-exposure curve. op ). Then in E op The pattern dimension (CD) displacement was calculated after 24 hours PED. Table 4 shows the formulation and lithography test results.

[0169] Table 4

[0170]

[0171] All weights in Table 4 are parts per hundred based on 100 parts of polymer A.

[0172] In Table 4, CD stands for critical dimension and is measured by pattern size. th Represents the minimum exposure energy that passes through the film during specific development conditions. E op represents the optimum exposure energy that gives the desired pattern size - this experiment targeted a pattern size of 15 μm.

[0173] From the results in Table 4, it can be seen that TINUVIN-123 has a stability sensitivity (CD and E) to the temperature change of PEB. op ). LUTONAL M40 provides Figure 4 PED CD stability as seen in . Figure 4 Depicts E op and CD displacement versus PEB temperature variation.

[0174] The PED CD-shift was evaluated by split PEB temperature. LUTONAL M40 gave better PED stability. Figure 5 As seen in the increase, TINUVIN M40 gives better PED stability.

[0175] As in Figure 6 As seen in , the comparison of cross-sectional pattern profiles shows that the combination of LUTONAL M40 and TINUVIN-123 gives a favorable pattern profile before and after PED.

[0176] The radiation sensitive compositions disclosed herein are advantageous in patterning and metallization methods. More specifically, the methods and compositions are used to deposit metal on a substrate, for example, to form micro-metal bumps on a metal layer. The present invention is particularly suitable for semiconductor manufacturing industries, such as semiconductor device and MEM manufacturing, and packaging applications, such as the formation of metal bumps in package on package, chip on chip, or flip chip bonding for microprocessors or memory devices.

Claims

1. A radiation-sensitive composition comprising: Photoacid generators; A quencher having a structure of formula (1) or (4) wherein R3 to R6 may be the same or different and are substituted or unsubstituted alkyl groups having 2 to 10 carbon atoms, and wherein R is a group or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, and wherein R7 is a group having the structure of formula (2): wherein X is a carbonyl group, an ester group, an amine group, an amide group, a urea group, a sulfone group, a sulfoxide group, an N-oxide group, a sulfonamide group, or a combination thereof, a substituted or unsubstituted C6 to C 14 Aryl, or C3 to C 12 Heteroaryl, wherein the substituent is halogen, hydroxy, cyano, nitro, C1 to C 12 Alkyl, C1 to C 12 Halogenated alkyl, C1 to C 12 Alkoxy, C3 to C 12 Cycloalkyl, amino, C2-C6 alkanoyl, carboxamido, substituted or unsubstituted C6 to C 14 Aryl, or C3 to C 12 Heteroaryl; wherein n is 1 or 2; an acid-labile polymer formed from a monomer comprising a vinyl aromatic monomer and a monomer comprising an acid-decomposable group; the acid-decomposable group being a tertiary alkyl ester group; and Solvent.

2. The radiation-sensitive composition according to claim 1, wherein X is a carbonate group, a sulfate group or a sulfonate group.

3. The radiation-sensitive composition according to claim 1, wherein The photoacid generator has a structure of formula (7): wherein R7 is a hydrogen atom, a substituted or unsubstituted straight or branched C1 to C 14 An alkyl group, a substituted heterocyclic group, or a halogen atom; and wherein R8 is a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, a halogen atom, or an aryl group having 6 to 20 unsubstituted carbon atoms.

4. The radiation-sensitive composition according to claim 1 or 2, further comprising: a polymer adhesion promoter, wherein the polymer adhesion promoter is a polymer compound having a structure of formula (13): Where R 21 is a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms.

5. The radiation-sensitive composition according to claim 1 or 2, wherein: The vinyl aromatic monomer is hydroxystyrene, the monomer containing an acid-decomposable group is a (meth)acrylic monomer containing a tertiary carbon as an acid-labile species, and wherein the acid-labile polymer has a weight average molecular weight of 10,000 to 30,000 g / mol.

6. The radiation-sensitive composition according to claim 1 or 2, further comprising: an aromatic azole compound; wherein the aromatic azole compound is a benzotriazole derivative having a structure of formula (14): Where R 22 is an alkyl group having 1 to 14 carbon atoms or an amine group.

7. The radiation-sensitive composition according to claim 1 or 2, wherein: The photoacid generator is present in an amount of less than 2 wt % of the total amount of monomers containing acid labile groups.

8. The radiation-sensitive composition according to claim 1 or 2, wherein: The acid labile polymer further comprises a second vinyl aromatic monomer.

9. The radiation-sensitive composition according to claim 1 or 2, wherein: The quencher is a basic quencher, wherein the amount of the basic quencher is present in an amount of 0.1 to 50 mole percent based on the total moles of the photoacid generator.

10. A method for forming a resist pattern, comprising: forming a radiation-sensitive film on a substrate; wherein the radiation-sensitive film comprises the radiation-sensitive composition as claimed in claim 1; exposing the radiation-sensitive film to activating radiation in a patterned manner; as well as The radiation-sensitive film is brought into contact with an alkaline developer to form a resist pattern.

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