Salt and photoresist containing it

Abstract

This application relates to photoresist compositions, methods for providing photoresist relief images, and salts and photoresists containing the same. Novel Te salt compounds are provided, comprising photoactive tellurium salt compounds suitable for extreme ultraviolet lithography.

Description

[0001] This invention patent application is a divisional application of the invention patent application with application number 201811283323.0, application date October 31, 2018, and invention title "Salt and Photoresist Containing the Same". Technical Field

[0002] This invention relates to novel salt compounds containing one or more Te atoms. In a preferred aspect, photoactive tellurium salt compounds are provided that can be used in extreme ultraviolet lithography. Background Technology

[0003] Extreme ultraviolet lithography (“EUVL”) is one of the leading alternatives to optical lithography for high-volume semiconductor manufacturing with feature sizes <20 nm. The extremely short wavelength (13.4 nm) is a key enabling factor for the high resolution required across multiple generations of technology. Furthermore, the overall system concept—scanning exposure, projection optics, mask format, and resist technology—is very similar to that used in current optical technologies. Like previous generations of lithography, EUVL consists of resist technology, exposure tooling technology, and masking technology. The main challenges are EUV source power and throughput. Any improvement in the EUV power supply will directly impact the currently stringent resist sensitivity specifications. In fact, a major issue in EUVL imaging is resist sensitivity; lower sensitivity requires higher source power or longer exposure times to fully expose the resist. Lower power levels also increase the impact of noise on the line edge roughness (“LER”) of the printed lines.

[0004] Various attempts have been made to modify the composition of EUV photoresist compositions to improve the performance of functional properties. Among others, a number of photosensitive compounds have been reported. See US Patents 8039194 and 8652712. See also US20150021289; US20150177613; and Fukunaga et al., Journal of Photo Polymer Science and Technology, 2017, 30(1), 103-3-107.

[0005] Electronic device manufacturers are constantly striving to improve the resolution of patterned photoresist images. There is a desire for novel photoresist compositions that can provide enhanced imaging capabilities, including novel photoresist compositions suitable for EUVL. Summary of the Invention

[0006] We now offer new salts and photoresists containing these salts. In a preferred aspect, the salts can be used as acid generators, including photoacid generators, and are particularly suitable for extreme ultraviolet lithography applications.

[0007] More specifically, in a first aspect, the salts of the present invention comprise one or more tellurium atoms, typically one or two tellurium atoms, including compounds of formula (I):

[0008]

[0009] Where R 1 R 2 and R 3 Each independently is C 6-60 Aryl, C 6-20 Fluoroaryl, C 1-20 heteroaryl, C 7-20 Aryl alkyl, C 7-20 Fluoroaryl, C 2-20 Heteroaryl or C 2-20 Fluoroaryl, C 1-20 Alkyl, C 1-20 fluoroalkyl, C 3-20 cycloalkyl, C 3-20 Fluorocycloalkyl, C 2-20 alkenyl, C 2-20 Fluoroolefins, each substituted or unsubstituted,

[0010] R 1 Connected to another group R via a single bond or linking group. 2 Or R 3 Forming rings, and

[0011] Z is an anion.

[0012] In certain preferred aspects, the tellurium salt (Te salt) may comprise one or more optional substituted phenyl substituents, such as a salt of any one of formulas (IIA) or (IIB):

[0013]

[0014] In formula (IIA):

[0015] R 4 and R 5 They are the same or different non-hydrogen substituents, such as C 1-10 Alkyl, C 1-10 fluoroalkyl, C 3-10 cycloalkyl, C 3-10 Fluorocycloalkyl, C 3-10 Cycloalkoxy or C 3-10 Fluorocycloalkoxy groups, each of which may be substituted or unsubstituted;

[0016] Each R 6 These are the same or different non-hydrogen substituents, such as halogens, -CN, -OH, C. 1-10 Alkyl, C 1-10fluoroalkyl, C 1-10 Alkoxy, C 1-10 Fluoroalkoxy, C 3-10 cycloalkyl, C 3-10 Fluorocycloalkyl, C 3-10 Cycloalkoxy or C 3-10 Fluorocycloalkoxy groups, except for halogens, -CN and -OH, each of which may be substituted or unsubstituted;

[0017] p is 0 (where R does not exist) 6 (groups) to integers from 5; and

[0018] Z is the counter anion.

[0019]

[0020] In equation (IIB):

[0021] Each R 6 Independently halogen, -CN, -OH, C 1-10 Alkyl, C 1-10 fluoroalkyl, C 1-10 Alkoxy, C 1-10 Fluoroalkoxy, C 3-10- cycloalkyl, C 3-10 Fluorocycloalkyl, C 3-10 Cycloalkoxy or C 3-10 Fluorocycloalkoxy groups, except for halogens, -CN and -OH, each of which may be substituted or unsubstituted;

[0022] Each p is 0 (where there is no R). 6 (groups) up to 5 identical or different integers; and

[0023] Z is the counter anion.

[0024] As described above, preferred Te-salts include those in which the tellurium atom is a ring member, such as compounds of formula (III):

[0025]

[0026] in:

[0027] X is a single bond or linking group, such as S, O, C=O, S=O, SO2 and OC=O (lactone); carbon, nitrogen, and oxygen together with the described Te atoms form a monocyclic group or a multiple fused or linked ring structure;

[0028] R 7 It is a non-hydrogen substituent, such as an optionally substituted alkyl or optionally substituted carbocyclic aryl;

[0029] Each R 7' is the same or different non-hydrogen ring substituent, the same such as halogen, -CN, -OH, and different such as optionally substituted alkyl, optionally substituted alkoxy or optionally substituted carbocyclic aryl;

[0030] q is an integer equal to 0 (where R is an integer equal to 0). 7 The maximum allowed valence from 'the absence of a group' to the ring member; and

[0031] Z is the counter anion.

[0032] Particularly preferred Te salts include fused-ring compounds, such as those of formula (IIIA):

[0033]

[0034] in:

[0035] R 8 It is a non-hydrogen substituent, such as an optionally substituted alkyl or optionally substituted carbocyclic aryl;

[0036] R 9 and R 10 It is the same or different non-hydrogen ring substituent, such as halogen, -CN, -OH, C 1-10 Alkyl, C 1-10 fluoroalkyl, C 1-10 Alkoxy, C 1-10 Fluoroalkoxy, C 3-10 cycloalkyl, C 3-10 Fluorocycloalkyl, C 3-10 Cycloalkoxy or C 3-10 Fluorocycloalkoxy groups, except for halogens, -CN and -OH, can be substituted or unsubstituted;

[0037] J is a single bond or a linking group suitably selected from S, O, C=O, S=O, SO2 and OC=O (lactone);

[0038] s and s' are each independently 0 (where R does not exist). 9 Or R 10 (substituents), integers 1, 2, 3, and 4; and

[0039] Z is the counter anion.

[0040] In some preferred embodiments, the Te salt will contain one or more acid-insecure groups, such as photoacid-insecure ester groups or acetal groups.

[0041] In the compounds of the present invention (including any of the compounds of formulas (I), (IIA), (IIB), (III), and (IIIA) above), the anion Z is suitably an inorganic or organic group. Suitable inorganic groups include, for example, halogens, such as I...- ,Br - SbF6 - BF4 - And B(C6F5)4. Suitable organic compounds may include aromatic and non-aromatic groups, including phenyl-containing anions and aliphatic anions, such as C 1-30 The alkyl group may suitably contain one or more anions, such as carboxyl groups, sulfonate groups, sulfonamide anions, or anions of sulfonamides. Preferred organic anions have one or more electron-withdrawing groups, such as fluorine.

[0042] In some preferred aspects, the Te salt of the present invention can be covalently linked to a polymer, for example, either the anionic or cationic component of the Te salt can be covalently linked to the polymer, or each of the anionic and cationic components of the Te salt can be covalently linked to the polymer.

[0043] In some preferred aspects, the Te salt may contain polymerizable groups such as unsaturated groups, for example, carbon-carbon unsaturated groups, including activated vinyl groups, such as acrylate moieties. These polymerizable groups can covalently link the acid generator to other composition components, such as photoresist resins, for reaction.

[0044] Preferred photoresists of this invention may comprise one or more Te salts and suitable polymer components in imaging-effective amounts as disclosed herein. One or more salts may suitably serve as acid-generating components in the photoresist composition. In this embodiment, the resist may comprise a mixture of different Te salt compounds, typically a mixture of two or three different Te salt compounds, and more typically a mixture consisting of a total of two different Te salt compounds.

[0045] The Te salts disclosed herein can also be used as photodegradable quenchers (PDQs), for example, in photoresist compositions with a different acid generator that produces a stronger acid upon photoactivation than the Te-containing PDQ.

[0046] For use as a PDQ, the Te salt is an anionic component with a relatively high pKa (e.g., aminosulfonic acids with pKa greater than 0 or carboxylic acids with pKa greater than 3). As mentioned herein, the pKa value is in aqueous solution at 23°C and can be determined experimentally or calculated, for example, using Advanced Chemistry Development (ACD) laboratory software version 11.02.

[0047] The preferred Te salt of the present invention used as a PDQ produces an acid weaker than the acid produced by different photoacid-generating compounds present in the same or adjacent compositions, such as the same photoresist composition. Therefore, without being bound by theory, the photodestructible quencher with a higher pKa in the unexposed photoresist region quenches the strong acid diffusing from the exposed region as the strong acid generated by different photoacid-generating agents migrates from the exposed region to the unexposed photoresist region. This can lead to the neutralization of the strong acid in the unexposed region and thus improve the lithography results.

[0048] Therefore, in certain preferred aspects, the difference in pKa between the acidic component of the Te-containing PDQ (a photoresist composition) and the acidic component of different photoacid-generating compounds present in the same photoresist composition is 0.5, 1, 2, 3, or 4 or higher.

[0049] Methods for forming embossed images (including pattern lines with a size less than 50 nm or less than 20 nm) of the photoresist composition of the present invention are also provided. Such methods may include, for example: a) applying the photoresist coating of the present invention onto a substrate; b) exposing the photoresist composition layer to active radiation, including EUV; and c) developing the exposed photoresist composition coating.

[0050] Substrates coated with the photoresist composition of the present invention, such as microelectronic wafers, are also provided. Electronic devices formed by the disclosed methods are also provided.

[0051] Other aspects of the invention are discussed below. Detailed Implementation

[0052] As mentioned in this article, acid-generating compounds can produce acids when exposed to activating radiation, such as EUV radiation, electron beam radiation, or other radiation sources, such as 193 nm wavelength radiation. The acid-generating compounds mentioned in this article can also be referred to as photoacid-generating compounds.

[0053] The term Te salt refers to a salt compound as disclosed herein that contains one or more Te atoms.

[0054] As discussed, preferred Te salts can be photoactive and reactive to lithographic radiation (e.g., 193 nm) and EUV radiation. These preferred Te salts can be used as photoactive components of photoresists. However, other aspects of the invention also include Te salts that may not be photoactive to such radiation, or at least cannot be used directly or otherwise as photoactive resist components.

[0055] As described above, preferred Te salts include those of formulas (I), (IIA), (IIB), (III), and (IIIA) as defined above.

[0056] In those of formulas (I), (IIA), (IIB), (III), and (IIIA) above, suitable non-hydrogen substituents may be, for example, halogens (F, Cl, Br, or I); cyano groups; nitro groups; optionally substituted C1-20 alkyl groups; optionally substituted C1-20 alkoxy groups, such as optionally substituted alkyl groups (e.g., optionally substituted C1-10 alkyl groups); optionally substituted alkenyl or ynyl groups, preferably having 2 to about 20 carbon atoms, such as alkenyl groups. propyl; optionally substituted ketone, preferably having 1 to about 20 carbon atoms; optionally substituted alkylthio group, preferably having 1 to about 20 carbon atoms; optionally substituted alkylsulfinyl group, preferably having 1 to about 20 carbon atoms; optionally substituted alkylsulfonyl group, preferably having 1 to about 20 carbon atoms; optionally substituted carboxyl group, preferably having 1 to about 20 carbon atoms (including groups such as -COOR′, where R′ is H or C). 1-8 Alkyl groups (including esters that are substantially unreactive with light acids); optionally substituted alkylaryl groups, such as optionally substituted benzyl; optionally substituted carbocyclic aryl groups, such as optionally substituted phenyl, naphthyl, or acenaphthel; or optionally substituted heterocyclic or heteroaryl groups, such as pyridyl, furanyl, pyrrole, thiophene, furan, imidazole, pyrazole, oxazole, isoxazole, thiazolium, isothiazole, triazole, furanzan, oxadiazole, thiazolium, dithiazolium, tetrazolium, pyran, thiopiperan, diazine, oxazine, thiazine, dioxane, and triazine; and polyaryl groups containing one or more of these moieties.

[0057] As described above, the Te salt of the above formula can be suitably substituted with one or more acid-indestructible groups at available positions. Suitable acid-indestructible groups can be a variety of moieties, including acid-indestructible esters and acetals, such as optionally substituted ethylcyclopentyl esters, methyladamantyl esters, ethyladamantyl esters, tert-butyl esters, phenyl esters, naphthyl esters, ethoxyethyl ethers, and esters. In some preferred aspects, the Te salt compounds of the present invention will contain one or two covalently linked acid-indestructible groups. As mentioned herein, during typical photolithography processes, including thermal exposure following any radiation exposure, the acid-indestructible moieties or groups (including acid-indestructible esters and acetals) react in the presence of the generated acid (from an acid-generating compound in the resist, which may be a Te salt present in the resist). The acid-indestructible groups mentioned herein may also be referred to as photo-acid-indestructible groups.

[0058] The Te salt compounds of the present invention are readily prepared. See, for example, the synthesis described in the examples below.

[0059] The particularly preferred compounds of the present invention include the following:

[0060]

[0061] In the above structure, Z is a counter anion defined as any one of the formulas (I), (IIA), (IIB), (III) and (IIIA) above.

[0062] Photoresist composition

[0063] As discussed above, the Te salts disclosed herein are suitable as radiation-sensitive components in photoresist compositions (including both positive and negative chemically amplified photoresist compositions).

[0064] The photoresist of the present invention typically comprises a polymer and one or more Te salts as disclosed herein. Preferably, the polymer has functional groups that impart alkaline aqueous developability to the photoresist composition. For example, polymers containing polar functional groups (such as hydroxyl or carboxylic acid ester groups) or acid-labile groups that can release such polar portions after photolithography are preferred. Preferably, the polymer is used in the photoresist composition in an amount sufficient to allow the photoresist to be developable with an alkaline aqueous solution.

[0065] The Te salts of the present invention are also suitably used with polymers comprising repeating units containing aromatic groups, such as optionally substituted phenyl groups, including phenol, optionally substituted naphthyl groups, and optionally substituted anthracene groups. Polymers containing optionally substituted phenyl groups (including phenols) are particularly suitable for a variety of resist systems, including those for EUV and electron beam imaging. For positively acting resists, the polymer preferably also contains one or more repeating units containing acid-labile groups. For example, in the case of polymers containing optionally substituted phenyl or other aromatic groups, the polymer may contain repeating units containing one or more acid-labile moieties, such as polymers formed by polymerizing monomers of acrylate or methacrylate compounds with acid-labile esters (e.g., tert-butyl acrylate or tert-butyl methacrylate). Such monomers may be copolymerized with one or more other monomers containing aromatic groups (e.g., styrene or vinylphenol monomers).

[0066] Preferred monomers for forming such polymers include: acid-insecure monomers having the following formula (V), lactone-containing monomers of formula (VI), alkali-soluble monomers of formula (VII) (for adjusting the dissolution rate in alkaline developers), and photoacid-generating monomers of formula (VIII), or combinations comprising at least one of the aforementioned monomers:

[0067]

[0068] Each R a Independently H, F, -CN, C 1-10 Alkyl or C1-10 Fluoroalkyl. In the acid-deprotectable monomer of formula (V), R b Independently for C 1-20 Alkyl, C 3-20 cycloalkyl, C 6-20 Aryl or C 7-20 Aryl alkyl groups, and each R b For independent or at least one R b Bonding to adjacent R b To form a cyclic structure. In the lactone-containing monomer of formula (VI), L is a monocyclic, polycyclic, or fused polycyclic C. 4-20 Contains a lactone group. In the base-soluble monomer of formula (VII), W is halogenated or non-halogenated, aromatic or non-aromatic. 2-50 The organic group contains a hydroxyl group and has a pKa of less than or equal to 12. In the photoacid generator monomer of formula (VIII), Q is ester- or non-ester-containing and fluorinated or non-fluorinated, and is C 1-20 Alkyl, C 3-20 cycloalkyl, C 6-20 Aryl or C 7-20 Aryl group; A is ester-containing or non-ester-containing and fluorinated or non-fluorinated, and is C 1-20 Alkyl, C 3-20 cycloalkyl, C 6-20 Aryl or C 7-20 Aryl group; Z - The anionic moiety contains carboxyl, sulfonate, sulfonamide, or sulfonamide anion; and G + It is a thionium or thionium cation.

[0069] Exemplary acid-labile monomers include, but are not limited to:

[0070]

[0071] Or a combination comprising at least one of the aforementioned monomers, wherein R a For H, F, -CN, C 1-6 Alkyl or C 1-6 Fluoroalkyl groups.

[0072] Suitable lactone monomers may be monomers of the following formula (IX):

[0073]

[0074] Where R a For H, F, -CN, C 1-6 Alkyl or C 1-6 fluoroalkyl, R is C 1-10Alkyl, cycloalkyl, or heterocyclic alkyl, and w is an integer from 0 to 5. In formula (IX), R is directly attached to the lactone ring or is usually attached to the lactone ring and / or one or more R groups, and the ester moiety is directly attached to or indirectly attached to the lactone ring via R.

[0075] Exemplary lactone-containing monomers include:

[0076]

[0077] Or a combination comprising at least one of the aforementioned monomers, wherein R a For H, F, -CN, C 1-10 Alkyl or C 1-10 Fluoroalkyl groups.

[0078] Suitable base-soluble monomers may be monomers of the following formula (X):

[0079]

[0080] Each R a Independently H, F, -CN, C 1-10 Alkyl or C 1-10 fluoroalkyl, where A is hydroxyl-containing or non-hydroxyl-containing, ester-containing or non-ester-containing, fluorinated or non-fluorinated. 1-20 Alkylene, C 3-20 Cycloalkylene, C 6-20 aryl or C 7-20 Arenealkylene, and x is an integer from 0 to 4, where when x is 0, A is a hydroxyl-containing C. 6-20 Alpha-aryl.

[0081] Exemplary base-soluble monomers include those monomers having the following structures:

[0082]

[0083] Or a combination of at least one of the foregoing, wherein R a For H, F, -CN, C 1-6 Alkyl or C 1-6 Fluoroalkyl groups.

[0084] Preferred photoacid-generating monomers include those of formula (XI) or (XII):

[0085]

[0086] Each R a Independently H, F, -CN, C 1-6 Alkyl or C 1-6 fluoroalkyl, where A is a fluorinated C 1-30 Alkylene, fluorinated C 3-30Cycloalkylene, fluorinated C 6-30 arylene or fluorinated C 7-30 Alkylene-arylene, and G + It is a thionium or thionium cation.

[0087] Preferably, in equations (XI) and (XII), A is –[(C(R 1 )2) x C(=O)O] b -C((R 2 )2) y (CF2) z -A group or a –C6F4- group substituted at the ortho, meta, or para positions, wherein each R 1 and R 2 Each is independently H, F, -CN, C 1-6 fluoroalkyl or C 1-6 Alkyl group, b is 0 or 1, x is an integer from 1 to 10, y and z are independently integers from 0 to 10, and the sum of y+z is at least 1.

[0088] Example preferred photoacid generating monomers include:

[0089]

[0090]

[0091] Or a combination of at least one of the foregoing, wherein each R a Independently H, F, -CN, C 1-6 Alkyl or C 1-6 fluoroalkyl, k preferably being an integer from 0 to 5; and G + It is a thionium or thionium cation.

[0092] Preferred photoacid-generating monomers may include thionium or monazine cations. Preferably, in formula (IV), G + Having formula (XIII):

[0093]

[0094] Where X is S or I; each R 0 Halogenated or non-halogenated and independently C 1-30 Alkyl, polycyclic or monocyclic C 3-30 Cycloalkyl, polycyclic or monocyclic C 4-30 aryl; or a combination comprising at least one of the foregoing, wherein when X is S, R 0 One of the groups is optionally attached to an adjacent R via a single bond. 0 A group, and a is 2 or 3, wherein a is 2 when X is I, or 3 when X is S.

[0095] Exemplary acid-producing monomers include those monomers having the following formula:

[0096]

[0097] Where R a It is H, F, -CN, C 1-6 Alkyl or C 1-6 Fluoroalkyl groups.

[0098] Polymers with acid-instable deblocking groups, particularly suitable for the positive chemical amplification photoresist of the present invention, have been disclosed in European Patent Application 0829766A2 (polymers with acetals and ketals) and European Patent Application EP0783136A2 (terpolymers and other copolymers comprising 1) styrene; 2) hydroxystyrene; and 3) acid-instable groups (specifically, alkyl acrylate acid-instable groups).

[0099] The molecular weight and polydispersity of the polymer used in the photoresist of this invention can suitably vary considerably. Suitable polymers include M w Those polymers with a molecular weight distribution of about 1,000 to about 50,000, more typically about 2,000 to about 30,000, and a molecular weight distribution of about 3 or less, more typically about 2 or less.

[0100] The photoresist of the present invention may also contain other substances. For example, other optional additives include photochemical and contrast dyes, anti-stripping agents, plasticizers, accelerators, sensitizers, photodegradable bases, etc. These optional additives are typically present in a low concentration in the photoresist composition.

[0101] The carboxylates or sulfonates containing the base material, which are photodegradable cations, preferably provide a mechanism for neutralizing acids from acid-degradable groups and limit the diffusion of photogenerated acids, thereby providing improved contrast in photoresists.

[0102] Light-destructible bases include those that react with weak (pKa>2) acids, such as C. 1-20 The carboxylic acid is anion-paired with a photodegradable cation, and preferably also suitable for the preparation of acid-generating compounds. Exemplary carboxylic acids include formic acid, acetic acid, propionic acid, tartaric acid, succinic acid, cyclohexylcarboxylic acid, benzoic acid, salicylic acid, and other such carboxylic acids.

[0103] Alternatively, other additives may include quenchers, which are non-photodegradable bases, such as those based on hydroxides, carboxylates, amines, imines, and amides. Preferably, such quenchers include C 1-30Organic amines, imines, or amides, or C, which may be a strong base (e.g., hydroxides or alkoxides) or a weak base (e.g., carboxylates). 1-30 Quaternary ammonium salts. Exemplary quenchers include amines such as tripropylamine, dodecylamine, 1,1',1”-nitrotriprop-2-ol, 1,1',1”,1”'-(ethyl-1,2-dimethylbis(nitrotrimethyl))tetraprop-2-ol; aryl amines such as diphenylamine, triphenylamine, aminophenol, and 2-(4-aminophenyl)-2-(4-hydroxyphenyl)propane; TB bases, hindered amines such as diazabicycloundecene (DBU) or diazabicyclononene (DBN); or ion quenchers, including quaternary alkylammonium salts such as tetrabutylammonium hydroxide (TBAH) or tetrabutylammonium lactate.

[0104] Surfactants include fluorinated and nonfluorinated surfactants, and are preferably nonionic. Exemplary fluorinated nonionic surfactants include perfluorinated C4 surfactants, such as FC-4430 and FC-4432 surfactants available from 3M; and fluorinated glycols, such as POLYFOX PF-636, PF-6320, PF-656, and PF-6520 fluorinated surfactants from Omnova.

[0105] Photoresists further include solvents generally suitable for dissolving, formulating, and coating the components used in the photoresist. Exemplary solvents include anisole; alcohols, including ethyl lactate, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; esters, including n-butyl acetate, 1-methoxy-2-propanol acetate, methoxyethoxypropionate, and ethoxyethoxypropionate; ketones, including cyclohexanone and 2-heptanone; and combinations comprising at least one of the foregoing solvents.

[0106] Such photoresists may include copolymers in amounts of 50 to 99 wt%, specifically 55 to 95 wt%, more specifically 60 to 90 wt%, and even more specifically 65 to 90 wt% by total solid weight. A photodegradable base (if used) may be present in the photoresist in amounts of 0.01 to 5 wt%, specifically 0.1 to 4 wt%, and even more specifically 0.2 to 3 wt% by total solid weight. A surfactant may be included in amounts of 0.01 to 5 wt%, specifically 0.1 to 4 wt%, and even more specifically 0.2 to 3 wt% by total solid weight. A quencher may be included in relatively small amounts, for example, 0.03 to 5 wt% by total solid weight. Other additives may be included in amounts of less than or equal to 30 wt%, specifically less than or equal to 20%, or even more specifically less than or equal to 10% by total solid weight. The total solids content of the photoresist composition may be from 0.5 to 50 wt%, specifically 1 to 45 wt%, more specifically 2 to 40 wt%, and even more specifically 5 to 30 wt%, based on the total weight of solids and solvents. The acid-generating compound should be present in an amount sufficient to produce a latent image in the photoresist coating. More specifically, one or more acid-generating compounds will suitably be present in an amount of about 1 to 50 wt% of the total solids of the photoresist. It should be understood that solids include copolymers, photodegradable bases, quenchers, surfactants, any added PAGs, and any optional additives, excluding solvents.

[0107] The coated substrate can be formed from a photoresist containing an acid-generating compound (which may be one or more Te salts as disclosed herein), present in an amount sufficient to generate a latent image in the resist and acid-generating compound coating. Such coated substrates include: (a) a substrate having one or more layers to be patterned on its surface; and (b) a layer of photoresist composition comprising the acid-generating compound above said one or more layers to be patterned. For EUV or electron beam imaging, the photoresist may suitably have a relatively high content of the acid-generating compound, for example, one or more of the acid-generating compounds comprising 5% to 10% to about 65% of the total solids of the resist. Typically, smaller amounts of the photosensitive component will be suitable for chemically amplified resists.

[0108] The photoresist of the present invention is generally prepared according to known procedures, but the photoresist includes one or more of the Te salts of the present invention and, in some respects, replaces the previously used photosensitive compounds in such photoresist formulations. The photoresist of the present invention can be used according to known procedures.

[0109] The substrate can be of any size and shape, and is preferably one suitable for photolithography, such as silicon, silicon dioxide, silicon-on-insulator (SOI), strained silicon, gallium arsenide; coated substrates, including those coated with silicon nitride, silicon oxynitride, titanium nitride, tantalum nitride; ultrathin gate oxides, such as hafnium oxide; metal or metal-coated substrates, including those coated with titanium, tantalum, copper, aluminum, tungsten, their alloys; and combinations thereof. Preferably, the substrate surface herein includes a critical dimension layer to be patterned, including, for example, one or more gate layers or other critical dimension layers on the substrate for semiconductor fabrication. Such substrates preferably include silicon, SOI, strained silicon, and other such substrate materials, formed into circular wafers having a diameter of, for example, 20 cm, 30 cm, or greater, or other sizes suitable for wafer fabrication.

[0110] Furthermore, the method of forming an electronic device includes (a) coating a photoresist composition layer on a substrate surface; (b) exposing the photoresist composition layer patternwise to activated radiation; and (c) developing the exposed photoresist composition layer to provide a photoresist relief image.

[0111] Coating can be achieved by any suitable method, including spin coating, spray coating, dip coating, blade coating, etc. Coating a photoresist layer is preferably achieved by spin coating a solvent containing photoresist using a coating rail, wherein the photoresist is applied to a rotating wafer. During application, the wafer can be rotated at speeds up to 4,000 rpm, preferably from about 500 rpm to 3,000 rpm, and more preferably from 1,000 to 2,500 rpm. The coated wafer is rotated to remove the solvent, and baked on a heated plate to remove residual solvent and free volume from the film to achieve uniform density.

[0112] Subsequently, pattern-by-pattern exposure is performed using an exposure tool (such as a stepper), wherein the film is irradiated through a patterned mask and thus exposed pattern by pattern. The method preferably uses advanced exposure tools capable of generating activation radiation at high-resolution wavelengths, including extreme ultraviolet (EUV) or electron beam radiation. It should be understood that exposure using activation radiation decomposes the PAG in the exposed region and generates acids and decomposition byproducts, and these acids subsequently undergo chemical changes in the polymer (disassembling acid-sensitive groups to generate base-soluble groups, or alternatively, catalyzing crosslinking reactions in the exposed region). Such exposure tools can have a resolution of less than 30 nm.

[0113] Subsequently, the development of the exposed photoresist layer is achieved by treating the exposed layer with a suitable developer capable of selectively removing either the exposed portion (where the photoresist is positive) or the unexposed portion (where the photoresist is cross-linkable in the exposed area, i.e., negative). Preferably, the photoresist is a positive type based on a polymer with acid-sensitive (deprotectable) groups, and the developer is preferably a metal ion-free tetraalkylammonium hydroxide solution, such as a 0.26N tetramethylammonium hydroxide aqueous solution. The pattern is formed by development.

[0114] Additionally, for positive photoresists, unexposed areas can be selectively removed by treatment with a non-polar solvent suitable for negative development. Procedures for negative development of positive photoresists are described in US2011 / 0294069. Typical non-polar solvents used for negative development are organic developers, such as solvents selected from ketones, esters, hydrocarbons, and mixtures thereof, for example acetone, 2-hexanone, methyl acetate, butyl acetate, and tetrahydrofuran.

[0115] When used in one or more of these patterning processes, photoresists can be used to manufacture electronic and optoelectronic devices, such as memory devices, processor chips (CPUs), graphics chips, and other such devices.

[0116] The following examples illustrate the present invention.

[0117] Examples 1-4: Synthesis of Te Salts

[0118] Example 1: The synthetic procedure for the Te salt (photoacid generator) TPTe AdOH-TFPS is shown in Procedure 1 below. The synthesis of the salt TPTe Cl (1) is described in WHH Gunther's Journal of Organometallic Chemistry, 1974, 74, 79-84. Aqad et al. described the synthesis of the salt AdOH-TFPS Na (2) in US Patent US934822B2. A solution prepared by stirring a mixture of 75 mL of dichloromethane and 75 mL of water containing salt 1 (10.0 g, 25.35 mmol) and salt 2 (11 g, 25.80 mmol) was prepared at room temperature. The organic phase was separated, washed five times with 50 mL of deionized water, concentrated, and poured into heptane to obtain the Te salt (photoacid generator compound) TPTe AdOH-TFPS.

[0119]

[0120] Example 2: The synthetic procedure for the Te salt (photoacid generator) PDBTe AdOH-TFPS is shown in Procedure 2 below. The synthesis of salt PDBTe BF4(3) was described by Sato et al. in Tetrahedron Letters, 36(16), 2803-6; 1995. A solution containing 75 mL of dichloromethane and 75 mL of water, comprising salt 3 (5.0 g, 11.72 mmol) and salt 2 (5.0 g, 5.70 mmol), was stirred at room temperature for 16 hours. The organic phase was separated, washed five times with 50 mL of deionized water, concentrated, and poured into heptane to obtain the Te salt (photoacid generator compound) PDBTe AdOH-TFPS.

[0121]

[0122] Example 3: The synthetic procedure for the Te salt (photosensitive compound) TPTe CS is shown in the following procedure 3. Thackeray et al. described the synthesis of silver camphor sulfonate (CSAg) in US Patent US20140186767A1. A solution containing 50 mL of methanol mixture of TPTe Cl (10.0 g, 25.35 mmol) and salt CSAg (8.6 g, 25.35 mmol) was stirred overnight at room temperature. The reaction mixture was filtered and concentrated to obtain the Te salt (photosensitive acid generating compound) TPTe CS.

[0123]

[0124] Example 4: The synthetic scheme for the Te salt (photosensitive compound) TPTe HAdC is shown in the following procedure 4. Sekley et al. described the synthesis of silver 3-hydroxyadamantane carboxylate (HAdCAg) in US Patent US20140186767A1. A solution containing 50 mL of a methanol mixture of TPTeCl (10.0 g, 25.35 mmol) and the salt HAdCAg (7.68 g, 25.35 mmol) was stirred overnight at room temperature. The reaction mixture was filtered and concentrated to obtain the Te salt (photosensitive acid generating compound) TPTeHAdC.

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[0126] Example 5-7: EUV Transmission Calculation

[0127] Transmission calculations illustrate the effect of using a novel tellurium salt on the absorbance of thin films under EUV irradiation. The transmittance of the films prepared from the composition examples under EUV exposure (13.5 nm) was calculated by inputting the composition's molecular formula and assuming a polymer density of 1.20 g / cm³. 3 And the film thickness is calculated as 60nm.

[0128] Example 5: Table 1 shows the calculated transmittance percentages of compositions comprising the base polymer P1 (shown in process 5) and a Te salt (photoacid generator). Comparative compositions C1 to C4 each comprise polymer P1 and 5 mol%, 10 mol%, 15 mol%, or 20 mol% of the photoacid generator triterpenic acid triphenylthionium (TPS Tf). Compositions I1 to I4 of the present invention each comprise polymer P1 and 5 mol%, 10 mol%, 15 mol%, or 20 mol% of the photoacid generator triterpenic acid triphenyltellurium (TPTe Tf). As can be seen from Table 1, lower transmittance is obtained for formulations containing the TPTe Tf of the present invention. Interestingly, formulation I1 containing 5 mol% TPTe Tf has lower transmittance than formulation C4 containing 20 mol% TPS Tf.

[0129]

[0130] Table 1

[0131]

[0132] Example 6: Table 2 below shows the calculated transmittance percentages of compositions containing polymer-bound PAG (PBP). Comparative composition C5 contains polymer PBP1, wherein the photoactive cation is triphenylsulfonium, and composition I5 of the present invention contains polymer PBP2, wherein the photoactive cation is triphenyltellurium (procedure 6). As can be seen from Table 2, lower transmittance is achieved for formulations containing the present invention's PBP2.

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[0134] Table 2

[0135]

[0136] Example 7: Table 3 below shows the calculated transmittance percentages of compositions containing polymer-bound PAG (PBP). Comparative composition C6 contains polymer PBP3, wherein a triphenylsulfonium cation is bound to the polymer backbone, and composition I6 of the present invention contains polymer PBP4, with a triphenyltellurium cation bound to the polymer backbone (procedure 7). As can be seen from Table 4 below, lower transmittance is achieved for formulations containing the present invention's PBP4.

[0137]

[0138] Table 3

[0139]

Claims

1. A photoresist composition comprising: Resin; and One or more salts of the following formula (I): in, R 1 R 2 and R 3 Each independently is C 6-60 Aryl, C 6-20 Fluoroaryl, C 1-20 heteroaryl, C 7-20 Aryl alkyl, C 7-20 Fluoroaryl, C 2-20 Heteroalkyl, C 2-20 Fluoroaryl, C 1-20 Alkyl, C 1-20 fluoroalkyl, C 3-20 cycloalkyl, C 3-20 Fluorocycloalkyl, C 2-20 alkenyl or C 2-20 Fluoroolefins, each substituted or unsubstituted, Among them, each R 1 With R 2 and / or R 3 Are they separate or connected to R? 2 and / or R 3 Forming rings, and Z includes counter anions. In this case, R is replaced by one or more acid-indestabilizing groups. 1 R 2 and R 3 One or more of the salts contain one or more acid-labile groups.

2. The photoresist composition as claimed in claim 1, wherein, The one or more salts correspond to the following formula (IIA): in, R 4 and R 5 Each independently is C 6-60 Aryl, C 6-20 Fluoroaryl, C 1-20 heteroaryl, C 7-20 Aryl alkyl, C 7-20 Fluoroaryl, C 2-20 Heteroalkyl, C 2-20 Fluoroaryl, C 1-20 Alkyl, C 1-20 fluoroalkyl, C 3-20 cycloalkyl, C 3-20 Fluorocycloalkyl, C 2-20 alkenyl or C 2-20 Fluoroolefins, each of which may or may not be substituted; Each R 6 It is the same or different non-hydrogen substituent, and it is C. 6-60 Aryl, C 6-20 Fluoroaryl, C 1-20 heteroaryl, C 7-20 Aryl alkyl, C 7-20 Fluoroaryl, C 2-20 Heteroalkyl, C 2-20 Fluoroaryl, C 1-20 Alkyl, C 1-20 fluoroalkyl, C 3-20 cycloalkyl, C 3-20 Fluorocycloalkyl, C 2-20 alkenyl or C 2-20 Fluoroolefins, each of which may or may not be substituted; p is an integer from 0 to 5, and R does not exist when p is 0. 6 Groups; and Z includes counteracting anions.

3. The photoresist composition as described in claim 1, wherein, The photoresist composition comprises one or more acid-generating compounds that are different from the one or more salts mentioned above.

4. A method for providing a photoresist relief image, comprising: a) Applying a coating of the photoresist of claim 1 onto a substrate; as well as b) Expose the photoresist composition layer to activation radiation and allow the exposed photoresist composition coating to develop.

5. The method of claim 4, wherein, The photoresist composition layer is exposed to 193nm or EUV radiation.

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