A deep ultraviolet chemically amplified positive photoresist composition and a patterning method

Abstract

This invention relates to the field of photoresist technology, and in particular to a deep ultraviolet chemically amplified positive photoresist composition and a patterning method. The deep ultraviolet chemically amplified positive photoresist composition comprises the following components: a polymer, a phenyl-containing compound, a photoacid-generating agent, a nitrogen-containing compound, a surfactant, and a solvent; the polymer includes polymer A, which has a structure as shown in formula (I): where R1 is selected from any one of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, cyclopentyl, and cyclohexyl; R2 is selected from any one of hydrogen, methyl, and ethyl; the molar percentage of structural unit x to structural unit y is 65–80 mol%: 20–35 mol%. This photoresist features a large photolithography process window, wide exposure tolerance, and large depth of focus. Photolithography on a high-reflectivity substrate without anti-reflective underlayer protection can obtain photoresist patterns with no standing waves, small CD fluctuations, and right-angled sidewalls.

Description

Technical Field

[0001] This invention relates to the field of photoresist technology, and in particular to a deep ultraviolet chemically amplified positive photoresist composition and a patterning method. Background Technology

[0002] As integrated circuit integration density increases and processing linewidths shrink, photolithography technology has evolved from G-line (436nm) lithography and I-line (365nm) lithography to deep ultraviolet KrF (248nm) lithography, ArF (193nm) lithography, and EUV (13.5nm) lithography. With changes in exposure wavelength, the composition and structure of photoresist also continuously change to ensure that the overall performance of the photoresist meets the requirements of the corresponding integrated circuit manufacturing process.

[0003] Design guidelines for semiconductor device processing with critical dimensions greater than 0.5 μm can be achieved using g-line (436 nm) photolithography. Design guidelines for semiconductor device processing with critical dimensions between 0.5 μm and 0.35 μm can be achieved using i-line (365 nm) photolithography. Design guidelines for semiconductor device processing with critical dimensions between 0.30 μm and 0.12 μm can be achieved using KrF excimer laser lithography at a wavelength of 248 nm.

[0004] Compared to g-line lithography, i-line lithography increases the amount of reflected light entering the photoresist film from the silicon wafer by 78%, and 248nm lithography increases the amount of reflected light entering the photoresist film from the silicon wafer by 132%. As the exposure wavelength shortens, the interference between the reflected light from the substrate and the incident light causes the standing wave effect to become more and more severe, and the CD fluctuation becomes more and more severe. The lithographic pattern may even show an inverted trapezoidal shape.

[0005] In g-line and i-line processes, post-exposure baking increases acid diffusion and reduces standing wave effects, enabling control of CD fluctuations within a reasonable range (less than 10%). However, chemically amplified positive photoresist, using 248nm light as the exposure source, is designed for semiconductor devices with critical dimensions of 0.30μm to 0.12μm, requiring even lower CD fluctuation control. Post-exposure baking alone is insufficient to manage CD fluctuations effectively. Before applying the photoresist, an anti-reflective layer is coated on the substrate. This layer absorbs reflected light from the substrate, reducing the amount of reflected light entering the photoresist layer. Optimizing the anti-reflective layer thickness minimizes reflected light entering the photoresist layer, significantly reducing CD fluctuations. The anti-reflective layer is removed in the subsequent etching process.

[0006] However, in the fabrication of N-wells and P-wells, ion implantation is performed directly using a photoresist pattern as a mask, without an intermediate etching step to remove the anti-reflection layer. Because the presence of the anti-reflection layer blocks ion implantation, when pre-fabricating the imaging photoresist pattern for ion implantation, an anti-reflection layer cannot be pre-coated on the substrate before applying the photoresist to suppress reflections from the substrate. As a result, the imaged photoresist pattern not only exhibits severe standing waves and large CD fluctuations, but also resembles an inverted trapezoid.

[0007] As the critical dimensions of semiconductor device fabrication shrink, photolithographic patterns become increasingly finer, and photoresist film thickness also decreases. There is a growing demand for photoresist patterns with minimal CD fluctuations, sidewalls perpendicular to the substrate, and excellent photolithography window properties. Therefore, there is a particular need for a photoresist that is readily available from readily available raw materials, easy to adjust in formulation, and capable of producing photoresist patterns without standing waves and with right-angled sidewalls on highly reflective substrates without anti-reflective underlayer protection, while maintaining exposure latitude and depth of focus.

[0008] In view of this, the present invention is hereby proposed. Summary of the Invention

[0009] The primary objective of this invention is to provide a deep ultraviolet chemically amplified positive photoresist composition, which features a large photolithography process window, a wide exposure tolerance, and a large depth of focus. Photolithography on a highly reflective substrate without anti-reflection protection can achieve photoresist patterns with no standing waves, small critical dimension (CD) fluctuations, and right-angled sidewalls.

[0010] A second objective of the present invention is to provide a patterning method comprising using the above-described deep ultraviolet chemically amplified positive photoresist composition, which is suitable for the fabrication processes of N-wells and P-wells in semiconductors.

[0011] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0012] This invention provides a deep ultraviolet chemically amplified positive photoresist composition, comprising the following components:

[0013] Polymers, phenyl-containing compounds, photoacid-producing agents, nitrogen-containing compounds, surfactants, and solvents;

[0014] The polymer includes polymer A, which has a structure as shown in formula (I):

[0015]

[0016] In the formula, R1 is selected from any one of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, cyclopentyl, and cyclohexyl;

[0017] R2 is selected from hydrogen, methyl, and ethyl;

[0018] The molar percentage of structural unit x to structural unit y is 80–65 mol% : 20–35 mol%.

[0019] Furthermore, the weight-average molecular weight of polymer A is 5000 to 25000.

[0020] Furthermore, in the polymer, the mass percentage of polymer A is 1% to 20%.

[0021] Preferably, in the polymer, the mass percentage of polymer A is 5% to 15%.

[0022] Furthermore, the polymer also includes polymer B, which has a structure as shown in formula (II):

[0023]

[0024] In the formula, R3 is a tertiary alkyl group.

[0025] Furthermore, the weight-average molecular weight of polymer B is 5000 to 25000.

[0026] Preferably, the molar percentages of structural unit a, structural unit b, and structural unit c are 60–70 mol%: 10–40 mol%: 0–25 mol%.

[0027] Furthermore, the phenyl-containing compound includes one or more of the following: compounds containing biphenyl, compounds containing polyphenyl aliphatic hydrocarbon groups, compounds containing naphthyl, compounds containing anthraceneyl, compounds containing phenanthrene, and compounds containing benzoic acid esters.

[0028] Preferably, the phenyl-containing compound includes compounds containing anthracene and / or compounds containing benzoic acid esters.

[0029] Preferably, the phenyl-containing compound includes one or more of 9-hydroxymethylanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dibutoxyanthracene, tert-butyl benzoate, and 1,4-tert-butyl p-benzoate.

[0030] Further, the mass ratio of the phenyl-containing compound to the polymer is 0.01 to 20:100.

[0031] Preferably, the mass ratio of the phenyl-containing compound to the polymer is 0.05 to 10:100.

[0032] Furthermore, the photo-induced acid-producing agent includes one or more of the following: thioonium salts, iodonium salts, N-imine sulfonates, diazomethane-based acid-producing agents, and nitrobenzene sulfonate-based acid-producing agents.

[0033] Preferably, the nitrogen-containing compound includes one or more of aliphatic amines, aliphatic alcoholic amines, alkyl hydroxide amines, alkoxyalkylamines, cyclic amines, and polymeric amines.

[0034] Preferably, the surfactant includes a siloxane-containing nonionic surfactant and / or a fluorine-containing nonionic surfactant.

[0035] Furthermore, the mass ratio of the photoacid-producing agent, the nitrogen-containing compound, the surfactant, and the polymer is 1–10:0.01–1:0.01–1:100.

[0036] Preferably, in the deep ultraviolet chemical amplification positive photoresist composition, the solvent has a mass percentage of 50% to 95%.

[0037] The present invention also provides an image forming method, comprising the following steps:

[0038] The deep ultraviolet chemical amplification positive photoresist composition described above is coated onto a substrate, dried, and then photolithographically imaged under a light source with an exposure wavelength of 245–250 nm.

[0039] Preferably, the substrate surface is not coated with an anti-reflective coating.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] The deep ultraviolet chemical amplification positive photoresist composition of the present invention suppresses standing waves and reduces CD fluctuations by adding a phenyl-containing compound with high light absorption at 248 nm to the photoresist; and a polymer with low activation energy to protect side groups and low protection rate, which has the characteristics of high resolution, wide exposure latitude, and large depth of focus; enabling the prepared deep ultraviolet positive photoresist to achieve photoresist patterns with no standing waves, small CD fluctuations, and right-angled sidewalls even when photolithographically applied to a high-reflectivity substrate without anti-reflection underlayer protection, and a large photolithography process window; and has the characteristics of wide exposure latitude and large depth of focus; and is applicable to the fabrication processes of N-wells and P-wells. Detailed Implementation

[0042] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0043] The following is a detailed description of a deep ultraviolet chemical amplification positive photoresist composition and a pattern formation method according to an embodiment of the present invention.

[0044] In some embodiments of the present invention, a deep ultraviolet chemically amplified positive photoresist composition is provided, comprising the following components:

[0045] Polymers, phenyl-containing compounds, photoacid-producing agents, nitrogen-containing compounds, surfactants, and solvents;

[0046] The polymer includes polymer A, which has a structure as shown in formula (I):

[0047]

[0048] In the formula, R1 is selected from any one of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, cyclopentyl, and cyclohexyl;

[0049] R2 is selected from hydrogen, methyl, and ethyl;

[0050] The molar percentage of structural unit x to structural unit y is 65–80 mol% : 20–35 mol%.

[0051] Structural unit x is The structural unit y is

[0052] In some embodiments of the present invention, the polymer is a polymer whose alkali solubility can be increased by the action of acid; the phenyl-containing compound is a compound that has high light absorption at a wavelength of 248 nm.

[0053] This invention, by adding a phenyl-containing compound with high light absorption at 248 nm and a polymer with low activation energy protecting side groups and low protection rate to a deep ultraviolet positive photoresist, along with other components, produces a deep ultraviolet positive photoresist composition that can achieve photoresist patterns without standing waves, with small CD fluctuations, and right-angled sidewalls even on highly reflective substrates without anti-reflective underlayer protection. Furthermore, it features a large photolithography window, high exposure latitude, and large depth of focus; it is applicable to the fabrication processes of N-wells and P-wells.

[0054] Compounds containing phenyl groups exhibit high light absorption at 248 nm, absorbing reflected light from the substrate layer, suppressing standing wave formation, reducing CD fluctuations, and preventing overexposure of the photoresist bottom to avoid inverted patterns. Polymers with low activation energy protecting side groups and low protection rates offer advantages such as large photolithography window, high resolution, wide exposure latitude, and large depth of focus. These properties can offset the loss of exposure latitude or depth of focus caused by the addition of high-absorbing materials, preventing a decrease in exposure latitude or depth of focus. If the protection rate of polymer A is controlled to be no higher than 35%, standing waves will not be exacerbated by the addition of polymer A; in fact, they may even be suppressed.

[0055] In some embodiments of the present invention, R1 is selected from any one of methyl, ethyl, and propyl, and R2 is selected from methyl or ethyl; the molar percentage of structural unit x to structural unit y is 65-75 mol%: 25-35 mol%.

[0056] In some embodiments of the present invention, the weight-average molecular weight of polymer A is 5,000 to 25,000; preferably, the weight-average molecular weight of polymer A is 10,000 to 20,000.

[0057] In some embodiments of the present invention, the mass percentage of polymer A in the polymer is 1% to 20%; typically, but not limitingly, for example, the mass percentage of polymer A in the polymer is 0.01%, 0.1%, 1%, 5%, 10%, 15%, or 20%, etc.; preferably, the mass percentage of polymer A in the polymer is 5% to 15%.

[0058] In some embodiments of the present invention, the polymer further includes polymer B, which has a structure as shown in formula (II):

[0059]

[0060] In the formula, R3 is a tertiary alkyl group. In some embodiments of the present invention, the tertiary alkyl group includes tertiary butyl or tertiary pentyl.

[0061] In some embodiments of the present invention, the weight-average molecular weight of polymer B is 5,000 to 25,000; preferably, the weight-average molecular weight of polymer B is 10,000 to 20,000; preferably, the molar percentage of structural unit a, structural unit b and structural unit c is 70 to 60 mol%: 10 to 40 mol%: 0 to 25 mol%.

[0062] Structural unit a is Structural unit b is Structural unit c is

[0063] In some embodiments of the present invention, the polymer further includes polymer C, which has a structure as shown in formula (III):

[0064]

[0065] In the formula, R4 is selected from any one of tertiary alkyl, tertiary alkoxycarbonyl, tertiary alkoxycarbonylalkyl, cycloalkyl and cycloether groups;

[0066] The molar percentage of structural unit p to structural unit q is 60–80 mol% : 20–40 mol%.

[0067] Structural unit p is Structural unit q is

[0068] In some embodiments of the present invention, R4 is selected from any one of tert-butyl, tert-pentyl, tert-butoxycarbonyl, tert-pentoxycarbonyl, tert-butoxycarbonylmethyl, tert-butoxycarbonylethyl, tert-pentoxycarbonylmethyl, tert-pentoxycarbonylethyl, cyclopentyl, 1-methylcyclopentyl, 1-ethylcyclopentyl, cyclohexyl, 1-methylcyclohexyl, 1-ethylcyclohexyl, tetrahydropyranyl, and tetrahydrofuranyl.

[0069] In some embodiments of the present invention, the weight-average molecular weight of polymer C is 5,000 to 25,000; preferably, the weight-average molecular weight of polymer C is 10,000 to 20,000.

[0070] In some embodiments of the present invention, the polymer is a mixture of two or more polymers; preferably, the polymer includes polymer A and polymer B.

[0071] In some embodiments of the present invention, the phenyl-containing compound includes one or more of the following: compounds containing biphenyl, compounds containing polyphenyl aliphatic hydrocarbon groups, compounds containing naphthyl, compounds containing anthraceneyl, compounds containing phenanthrene, compounds containing benzoic acid, and compounds containing benzoic acid esters. Specifically, the biphenyl or polyphenyl aliphatic hydrocarbon group exhibits higher absorption at 248 nm than the phenyl group, and even higher absorption than p-hydroxystyrene.

[0072] In some embodiments of the present invention, the compounds containing biphenyl include one or more of diphenyl, 4,4'-dimethylbiphenyl, 4-biphenylphenol, 4,4'-biphenyldiphenol, and 2,6-diphenylphenol.

[0073] In some embodiments of the present invention, the compounds containing polyphenyl aliphatic hydrocarbon groups include one or more of triphenylmethane, α,α,α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene (TPPA), and phenolic resins.

[0074] In some embodiments of the present invention, the naphthyl-containing compound includes one or more of naphthalene, methylnaphthalene, 1-naphthol, di-1-naphthylethanol and naphthyl methacrylate.

[0075] In some embodiments of the present invention, compounds containing anthracene groups include one or more of anthracene, anthracene phenol, methyl anthracene, 9-hydroxymethyl anthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dibutoxyanthracene, and anthracene methacrylate.

[0076] In some embodiments of the present invention, the phenanthrene-containing compound includes one or more of 9-methylphenanthrene, 9,10-dimethylphenanthrene, phenanthrenephenol, phenanthrene methanol, and phenanthrene methacrylate.

[0077] In some embodiments of the present invention, the compounds containing benzoic acid esters include one or more of tert-butyl benzoate, tert-butyl 1,4-dibenzoate, and poly(p-hydroxystyrene-co-p-ethylene tert-butyl benzoate).

[0078] In some specific embodiments of the present invention, the phenyl-containing compounds include anthracene-containing compounds and / or benzoic acid ester-containing compounds; preferably, the phenyl-containing compounds include one or more of 9-hydroxymethyl anthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dibutoxyanthracene, tert-butyl benzoate, and tert-butyl 1,4-p-dibenzoate.

[0079] In some embodiments of the invention, the mass ratio of the phenyl-containing compound to the polymer is 0.01 to 20:100; typically, but not limitingly, for example, the mass ratio of the phenyl-containing compound to the polymer is 0.01:100, 1:100, 5:100, 10:100, 15:100, or 20:100; preferably, the mass ratio of the phenyl-containing compound to the polymer is 0.05 to 10:100.

[0080] In some embodiments of the present invention, the photo-induced acid-producing agent includes one or more of thioonium salts, iodonium salts, N-imine sulfonates, diazomethane-based acid-producing agents, and nitrobenzene sulfonate-based acid-producing agents.

[0081] Under KrF laser irradiation, the photoacid-producing agent absorbs light energy and decomposes into acid. During the baking process after exposure, the acid catalyzes the removal of hydrophobic side chains from the polymer.

[0082] In some embodiments of the present invention, the thionium salt has a structure as shown in formula (IV):

[0083]

[0084] In some embodiments of the present invention, the iodonium salt has a structure as shown in formula (V):

[0085]

[0086] N-Imine sulfonates have structures as shown in formula (VI) or formula (VII):

[0087]

[0088] In the formula, R5, R6 and R7 are each independently selected from hydrogen, methyl, hydroxyl, tert-butyl, methoxy and tert-butoxy; R8 is selected from trifluoromethyl, perfluorobutyl, perfluorooctyl, p-tolyl and camphene.

[0089] In some embodiments of the present invention, the diazomethane-based acid-producing agents include bis(alkylsulfonyl)diazomethane and / or bis(arylsulfonyl)diazomethane.

[0090] In some embodiments of the present invention, bis(alkylsulfonyl)diazomethane includes one or more of bis(isopropylsulfonyl)diazomethane, bis(tert-butylsulfonyl)diazomethane, bis(1,1-dimethylethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, and bis(cyclopentylsulfonyl)diazomethane.

[0091] In some embodiments of the present invention, bis(arylsulfonyl)diazomethane includes bis(p-toluenesulfonyl)diazomethane and / or bis(2,4-dimethylphenylsulfonyl)diazomethane.

[0092] In some embodiments of the present invention, the nitrobenzenesulfonate acid-generating agents include one or more of 2-nitrobenzenesulfonate, 2,4-dinitrobenzenesulfonate, and 2,6-dinitrobenzenesulfonate.

[0093] In some embodiments of the present invention, the nitrogen-containing compound includes one or more of aliphatic amines, aliphatic alcoholic amines, alkyl hydroxide amines, alkoxyalkylamines, cyclic amines, and polymeric amines.

[0094] In deep ultraviolet positive photoresist, during the period from exposure to post-exposure baking, the acid on the surface of the photoresist film is neutralized by amine contaminants in the environment, causing the surface layer to be insoluble during development, resulting in post-exposure stability issues. Furthermore, excessive acid diffusion during post-exposure baking can cause problems with image dimensional accuracy. To improve post-exposure stability and prevent excessive acid diffusion, a nitrogen-containing compound is added as an acid quencher to the deep ultraviolet positive photoresist of this invention.

[0095] In some embodiments of the present invention, the aliphatic amine includes one or more of diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, tri-n-octylamine, and dioctylmethylamine; preferably, the aliphatic amine includes alkyl tertiary amines.

[0096] In some embodiments of the present invention, the aliphatic alkanolamine includes one or more of diethanolamine, triethanolamine, and triisopropanolamine; preferably, the aliphatic alkanolamine includes alkyl alcohol tertiary amines.

[0097] In some embodiments of the present invention, the alkylamine hydroxide includes one or more of tetraethylamine hydroxide, tetrabutylamine hydroxide, and lactate of tetrabutylamine hydroxide; preferably, the alkylamine hydroxide includes tetrabutylamine hydroxide and its lactate.

[0098] In some embodiments of the present invention, alkoxyalkylamines include one or more of tri-(2-methoxymethoxyethyl)amine, tri-2-(2-methoxy(ethoxy)ethylamine) and tri-(2-(2-methoxyethoxy)methoxyethoxyamine); preferably, alkoxyalkylamines include tri-2-(2-methoxy(ethoxy)ethylamine).

[0099] In some embodiments of the present invention, the cyclic amine includes one or more of pyridine, methylpyridine, ethylpyridine, and 1,4-diazabicyclo[2,2,2]octane.

[0100] In some embodiments of the present invention, the polymeric amines include polyethylpyridine and / or BASF’s Tetronic series of polymeric amines.

[0101] In some embodiments of the present invention, the surfactant includes siloxane-containing nonionic surfactants and / or fluorine-containing nonionic surfactants.

[0102] Adding surfactants can improve the leveling and film uniformity of photoresist, prevent the formation of coating streaks, and reduce coating defects.

[0103] In some embodiments of the present invention, the nonionic surfactants containing siloxanes include BYK series surfactants from BAK Corporation and / or Silwet series surfactants from Momentive Corporation; the BYK series surfactants include one or more of BYK-308, BYK-310, DYK-320 and BYK-323; the Silwet series surfactants include Silwet L-77 and / or Silwet L-71.

[0104] In some embodiments of the present invention, the fluorinated nonionic surfactants include 3M's FC series surfactants and / or Chemours' FS series surfactants; the FC series surfactants include FC-4430 and / or FC-4432; and the FS series surfactants include FS-3000 and / or FS-3100.

[0105] This invention does not impose strict limitations on photoacid generators, nitrogen-containing compounds, and surfactants; known photoacid generators, nitrogen-containing compounds, and surfactants used in conventional photoresist compositions can be used.

[0106] The solvent used in this invention is any solvent capable of dissolving polymers, phenyl-containing compounds, photoacid generators, nitrogen-containing compounds, and surfactants in deep ultraviolet positive photoresists to produce a homogeneous solution.

[0107] In some embodiments of the present invention, the solvent includes one or more of ketones, polyols and their derivatives, cyclic ethers, esters and aromatic hydrocarbons.

[0108] In some embodiments of the present invention, ketones include one or more of acetone, methyl ethyl ketone, cyclohexanone, methyl isopentyl ketone, and 2-heptanone.

[0109] In some embodiments of the present invention, the polyols and their derivatives include one or more of 1,2-ethylene glycol, diethylene glycol, propylene glycol, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate (PGMEA).

[0110] In some embodiments of the present invention, cyclic ethers include tetrahydrofuran and / or dioxane.

[0111] In some embodiments of the present invention, the esters include one or more of methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, and γ-butyrolactone.

[0112] In some embodiments of the present invention, aromatic hydrocarbons include toluene and / or xylene.

[0113] In some embodiments of the present invention, the mass ratio of photoacid-producing agent, nitrogen-containing compound, surfactant and polymer is 1-10:0.01-1:0.01-1:100.

[0114] In some embodiments of the present invention, the solvent in the deep ultraviolet chemical amplification positive photoresist composition is 50% to 95% by mass.

[0115] In some embodiments of the present invention, a method for preparing the above-mentioned deep ultraviolet chemical amplification positive photoresist composition is also provided, comprising: mixing each component evenly to obtain the deep ultraviolet chemical amplification positive photoresist composition.

[0116] In some embodiments of the present invention, a pattern forming method is also provided, comprising the following steps:

[0117] The above-mentioned deep ultraviolet positive chemical amplification photoresist composition was coated on the substrate, dried, and then photolithographically imaged under a light source with an exposure wavelength of 245-250 nm.

[0118] In some embodiments of the present invention, photolithography is performed under a light source with an exposure wavelength of 248 nm.

[0119] In some embodiments of the present invention, the substrate surface is not coated with an anti-reflective coating.

[0120] In some embodiments of the present invention, the pattern forming method includes the following steps:

[0121] After hexamethyldisilane is vapor-deposited onto the substrate surface, a deep ultraviolet chemical amplification positive photoresist composition is coated onto the vapor-deposited substrate surface and then baked; then exposed under a light source with an exposure wavelength of 248nm; after baking, the exposed substrate is developed with a developer.

[0122] Example 1

[0123] The deep ultraviolet chemical amplification positive photoresist composition provided in this embodiment includes the following components by weight:

[0124] 0.75 parts of a PGMEA solution of polymer A (30.2% by mass), 10.9 parts of a PGMEA solution of polymer B (49% by mass), 0.152 parts of bis-tert-butylphenyl iodomonium camphor sulfonate, 0.15 parts of 9-hydroxymethyl anthracene, 1.52 parts of a PGMEA solution of tetrabutylammonium hydroxide (1% by mass), 0.816 parts of a PGMEA solution of BYK-310 (1% by mass), and 43.24 parts of PGMEA;

[0125] In the structural formula of polymer A, R1 is ethyl, R2 is methyl, x:y = 70 mol%: 30 mol%, and the weight-average molecular weight is 16500;

[0126] In the structural formula of polymer B, R3 is tert-butyl, a:b:c = 65 mol%: 20 mol%: 15 mol%; the weight-average molecular weight is 14680.

[0127] The method for preparing the deep ultraviolet chemical amplification positive photoresist composition provided in this embodiment includes: mixing the above components evenly, filtering through a 0.1μm polytetrafluoroethylene microporous filter membrane, and obtaining the deep ultraviolet chemical amplification positive photoresist composition.

[0128] Example 2

[0129] The deep ultraviolet chemical amplification positive photoresist composition provided in this embodiment includes the following components by weight:

[0130] 0.75 parts of a PGMEA solution of polymer A (30.2% by mass), 10.9 parts of a PGMEA solution of polymer B (49% by mass), 0.152 parts of bis-tert-butylphenyl iodomonium camphor sulfonate, 0.2 parts of tert-butyl 1,4-dibenzoate, 1.52 parts of a PGMEA solution of tetrabutylammonium hydroxide (1% by mass), 0.816 parts of a PGMEA solution of BYK-310 (1% by mass), and 43.24 parts of PGMEA;

[0131] In the structural formula of polymer A, R1 is ethyl, R2 is methyl, x:y = 70 mol%: 30 mol%, and the weight-average molecular weight is 16500;

[0132] In the structural formula of polymer B, R3 is tert-butyl, a:b:c = 65 mol%: 20 mol%: 15 mol%, and the weight-average molecular weight is 14680.

[0133] The method for preparing the deep ultraviolet chemical amplification positive photoresist composition provided in this embodiment includes: mixing the above components evenly, filtering through a 0.1μm polytetrafluoroethylene microporous filter membrane, and obtaining the deep ultraviolet chemical amplification positive photoresist composition.

[0134] Comparative Example 1

[0135] The deep ultraviolet chemically amplified positive photoresist composition provided in this comparative example comprises the following components by weight:

[0136] 10.9 parts of a 30.2% polymer B PGMEA solution, 0.152 parts of bis-tert-butylphenyl iodonium camphor sulfonate, 1.52 parts of a 1% tetrabutylammonium hydroxide PGMEA solution, 0.816 parts of a 1% BYK-310 PGMEA solution, and 43.24 parts of PGMEA;

[0137] In the structural formula of polymer B, R3 is tert-butyl, a:b:c = 65 mol%: 20 mol%: 15 mol%, and the weight-average molecular weight is 14680.

[0138] The preparation method of the deep ultraviolet chemical amplification positive photoresist composition provided in this comparative example includes: mixing the above components evenly, filtering through a 0.1 μm polytetrafluoroethylene microporous filter membrane, and obtaining the deep ultraviolet chemical amplification positive photoresist composition.

[0139] Comparative Example 2

[0140] The deep ultraviolet chemically amplified positive photoresist composition provided in this comparative example comprises the following components by weight:

[0141] 10.9 parts of a PGMEA solution of polymer B (30.2% by mass), 0.152 parts of bis-tert-butylphenyl iodonium camphor sulfonate, 0.15 parts of 9-hydroxymethyl anthracene, 1.52 parts of a PGMEA solution of tetrabutylammonium hydroxide (1% by mass), 0.816 parts of a PGMEA solution of BYK-310 (1% by mass), and 43.24 parts of PGMEA;

[0142] In the structural formula of polymer B, R3 is tert-butyl, a:b:c = 65 mol%: 20 mol%: 15 mol%, and the weight-average molecular weight is 14680.

[0143] The method for preparing the deep ultraviolet positive photoresist provided in this comparative example includes: mixing the above components evenly, filtering through a 0.1 μm polytetrafluoroethylene microporous filter membrane, and obtaining a deep ultraviolet chemically amplified positive photoresist composition.

[0144] Experimental Example 1

[0145] The substrate was pretreated by pre-depositing hexamethyldisilane without applying an anti-reflective coating to increase the adhesion between the photoresist and the substrate. The deep ultraviolet chemical amplification positive photoresist compositions of Examples 1-2 and Comparative Examples 1-2 were spin-coated onto the pretreated substrate. The photoresist-coated substrate was pre-baked on a hot plate (PAB) at 110°C for 90 seconds, adjusting the rotation speed to achieve a film thickness of 0.21 μm after drying. Then, the substrate was irradiated using a 248 nm exposure machine [ASMLPAS 5500 / 850 Scanner] through an inter-strip mask. The irradiation conditions were as follows: exposure mode was annular, NA value was 0.8, and Sigma outer / Sigma inner = 0.7 / 0.375. The exposure dose was gradually varied. After exposure, the substrate was post-baked on a hot plate at 130°C for 90 seconds, and then developed using 0.26 N TMAH spray for 60 seconds.

[0146] The developed image was observed using a Hitachi S9220 electron microscope to determine the optimal exposure for the 0.15μm 1:1 equidistant space. This exposure was then used as the center exposure for Focus-Energy Matrix exposure mode. The Hitachi S9220 electron microscope was used again to determine the exposure energy latitude and depth of focus for the 0.15μm dense space. The exposed slide was then sectioned, and the morphology, standing wave characteristics, and sidewall morphology of the 0.15μm 1:1 equidistant space were observed using a Hitachi S-4800 scanning electron microscope.

[0147] Table 1

[0148]

[0149]

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A deep ultraviolet chemically amplified positive photoresist composition, characterized in that, It consists of the following components: Polymers, phenyl-containing compounds, photoacid-producing agents, nitrogen-containing compounds, surfactants, and solvents; The polymer includes polymer A, which has a structure as shown in formula (I): In the formula, R1 is selected from any one of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, cyclopentyl, and cyclohexyl; R2 is selected from hydrogen, methyl, and ethyl; The molar percentage of structural unit x to structural unit y is 80–65 mol% : 20–35 mol%. The polymer also includes polymer B, which has a structure as shown in formula (II): In the formula, R3 is a tertiary alkyl group; In the polymer, the mass percentage of polymer A is 1% to 15%; The mass ratio of the phenyl-containing compound to the polymer is 1 to 5:100; The photo-induced acid-producing agent is any one of thioonium salts, iodonium salts, N-imine sulfonates, diazomethane-based acid-producing agents, and nitrobenzene sulfonate-based acid-producing agents; The phenyl-containing compound is one or more of 9-hydroxymethylanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dibutoxyanthracene, tert-butyl benzoate, and 1,4-tert-butyl p-benzoate. The patterning method of the deep ultraviolet chemical amplification positive photoresist composition includes: coating the deep ultraviolet chemical amplification positive photoresist composition onto a substrate, drying it, and then photolithographically imaging it under a light source with an exposure wavelength of 245-250 nm.

2. The deep ultraviolet chemically amplified positive photoresist composition according to claim 1, characterized in that, The weight-average molecular weight of polymer A is 5000 to 25000.

3. The deep ultraviolet chemically amplified positive photoresist composition according to claim 1, characterized in that, The weight-average molecular weight of polymer B is 5000 to 25000.

4. The deep ultraviolet chemically amplified positive photoresist composition according to claim 1, characterized in that, The molar percentages of structural unit a, structural unit b, and structural unit c are 60–70 mol% : 10–40 mol% : 0–25 mol%.

5. The deep ultraviolet chemically amplified positive photoresist composition according to claim 1, characterized in that, The nitrogen-containing compounds include one or more of aliphatic amines, aliphatic alcoholic amines, alkyl hydroxide amines, alkoxyalkylamines, cyclic amines, and polymeric amines.

6. The deep ultraviolet chemically amplified positive photoresist composition according to claim 1, characterized in that, The surfactants include nonionic surfactants containing siloxanes and / or nonionic surfactants containing fluorine.

7. The deep ultraviolet chemically amplified positive photoresist composition according to claim 1, characterized in that, The mass ratio of the photoacid-producing agent, the nitrogen-containing compound, the surfactant, and the polymer is 1 to 10: 0.01～1：0.01～1：100。 8. The deep ultraviolet chemically amplified positive photoresist composition according to claim 1, characterized in that, In the deep ultraviolet chemical amplification positive photoresist composition, the solvent has a mass percentage of 50% to 95%.

9. A method for forming a pattern, characterized in that, Includes the following steps: The deep ultraviolet chemical amplification positive photoresist composition according to any one of claims 1 to 8 is coated on a substrate, dried, and then photolithographically imaged under a light source with an exposure wavelength of 245 to 250 nm.

10. The pattern forming method according to claim 9, characterized in that, The substrate surface was not coated with an anti-reflective coating.

Images