Photoresist, photoresist cured film, and method for patterning photoresist

Abstract

This application relates to the field of functional polymer materials technology, and provides a photoresist, a photoresist-cured film, and a method for patterning the photoresist. The photoresist comprises a polyamic acid-polyamide ester resin, an alkaline catalyst, a crosslinking agent, a coupling agent, a photoresist, and a first organic solvent. The photoresist can simultaneously achieve imidization and curing of the polyimide resin therein at a relatively low temperature, and the cured photoresist-cured film exhibits warp resistance and high mechanical strength.

Description

Technical Field

[0001] This application relates to the field of functional polymer materials technology, and in particular to a photoresist, a photoresist curing film, and a method for patterning photoresist. Background Technology

[0002] For a long time, surface protective films and interlayer insulating layers of electronic components have preferred resins such as polyimide and polybenzoxazole, which have good heat resistance and mechanical properties. However, the preparation of such resins inevitably requires high-temperature dehydration condensation of precursors with processing properties to obtain films with excellent heat resistance and mechanical properties. This process generally requires high-temperature treatment at 350°C to 400°C.

[0003] With the continuous upgrading of integrated circuit packaging technology, fan-out wafer level packaging (FOWLP), which has lower cost, smaller size and higher I / O density, has gradually become the mainstream in the market. It further reduces the package thickness and interconnect distance by using multiple redistribution layers, but at the same time, the increase in I / O density puts forward higher requirements for the performance of the insulating layer.

[0004] The main problems faced by FOWLP (Folded Surface Mount Technology) are warpage and waferbow. Warpage distorts the package plane, eventually leading to stress concentration and package breakage. Reducing residual stress is the primary method to address warpage, which can be achieved by lowering the maximum processing temperature during the manufacturing process. However, considering the increased copper density due to increased package density, excessively high processing temperatures will amplify the difference in thermal expansion properties between the copper dielectric and the insulating layer, which is detrimental to the packaging process. Therefore, lowering the curing temperature of the photosensitive resin in the dielectric insulating layer, such as below 250°C or lower, is crucial for resolving film warpage and waferbow. Summary of the Invention

[0005] The purpose of this application is to provide a photoresist, a photoresist curing film, and a method for patterning photoresist. The photoresist can simultaneously achieve imidization and curing of the polyimide resin within it at a relatively low temperature (not exceeding 250°C), and the cured photoresist film exhibits warp resistance and high mechanical strength.

[0006] In a first aspect, this application provides a photoresist comprising a polyamic acid-polyamide ester resin, an alkaline catalyst, a crosslinking agent, a coupling agent, a photoresist, and a first organic solvent, wherein the polyamic acid-polyamide ester resin has the structure shown in Formula 1:

[0007]

[0008] In Equation 1, n ≥ 10;

[0009] M includes at least one of the structural unit 1 shown in Formula A and at least one of the optional structural unit 2 shown in Formula B:

[0010]

[0011] in, Indicates the connection key.

[0012] X1 and X2 may be the same or different, and each is an independent group containing an alicyclic group and / or an aromatic group;

[0013] Y1 and Y2 may be the same or different, and each is an independent group containing an aliphatic group and / or an aromatic group;

[0014] p is an integer not less than 1;

[0015] Each R may be the same or different, and each is independently a hydrogen or an alkyl group having 1 to 4 carbon atoms;

[0016] The weight-average molecular weight of the polyamic acid-polyamide ester resin is 5,000 to 100,000.

[0017] The alkaline catalyst is a DBU salt latent catalyst and / or a DBN salt latent catalyst.

[0018] Secondly, this application provides a photoresist curing film, which is formed by curing the photoresist.

[0019] Thirdly, this application provides a method for patterning photoresist, the method comprising the following steps: coating the photoresist described in the first aspect of this application onto a substrate, and sequentially subjecting it to pre-baking, exposure, development and curing to form a cured film pattern layer on the substrate.

[0020] The photoresist provided in this application is a positive photosensitive resin composition comprising polyamic acid-polyamide ester resin, an alkaline catalyst, etc. The use of a DBU salt latent catalyst and / or a DBN salt latent catalyst enables the polyamic acid-polyamide ester resin to achieve a high degree of imidization at a lower temperature. This helps suppress film warpage caused by excessively high imidization temperatures during the curing process of the photoresist coating on the substrate. Furthermore, the introduction of crosslinking agents and coupling agents into the photoresist further suppresses warpage while ensuring high mechanical and adhesive properties of the cured film. The photoresist of this application is particularly suitable for insulating materials with specific pattern requirements in chips.

[0021] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0022] Figure 1The image shows the infrared absorption spectrum of the cured film A.

[0023] Figure 2 The image shows the infrared absorption spectrum of the cured film B.

[0024] Figure 3 This is an SEM image of the photolithographic pattern formed by photoresist P1 after photolithographic curing in Example 1. Detailed Implementation

[0025] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0028] In this application, the term "optionally" means that the events or circumstances described below may or may not occur. For example, "M includes structural unit 1 and optional structural unit 2" means that M includes structural unit 1, and M may or may not include structural unit 2.

[0029] In this application, the term "substituted or unsubstituted" means that the functional group described after the term may or may not have substituents. For example, "substituted or unsubstituted phenyl" refers to a phenyl with substituents or an unsubstituted phenyl. The number of substituents can be one or more, and the substituents can be deuterium, halogen groups (e.g., chlorine, fluorine, bromine, iodine), trifluoromethyl, cyano, heteroaryl, aryl, alkyl, deuterated alkyl, haloalkyl, cycloalkyl, alkoxy, aryloxy, etc.

[0030] In this application, aromatic groups include aryl and heteroaryl groups. Aryl refers to a group derived from an aromatic carbon ring. Aryl groups can be monocyclic aryl (e.g., phenyl), fused-ring aryl (e.g., naphthyl), two or more monocyclic aryl groups (e.g., biphenyl) conjugated by carbon-carbon bonds, monocyclic aryl and fused-ring aryl groups conjugated by carbon-carbon bonds, or two or more fused-ring aryl groups conjugated by carbon-carbon bonds. Specific examples of aryl groups include, but are not limited to, phenyl, naphthyl, fluorenyl, anthracene, phenanthryl, biphenyl, terphenyl, benzo[9,10]phenanthryl, pyrene, benzofluoranthracene, etc. A heteroaryl group is an aromatic ring containing one, two, or more heteroatoms, which can be at least one of B, O, N, P, Si, Se, and S. Heteroaryl groups can be monocyclic heteroaryl or fused-ring heteroaryl. Specific examples of heteroaryl groups include, but are not limited to, thiophene, furanyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridinyl, triazinyl, acridinel, pyridazinyl, quinolinyl, quinazolinyl, quinoxazinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, isoquinolinyl, indolyl, carbazole, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazole, benzothiophene, dibenzothiophene, thiophenothiophene, benzofuranyl, phenanthrololinyl, isoxazolyl, thiadiazolyl, phenthiazinyl, phenoxthial, dibenzo-p-dioxinyl, etc.

[0031] In this application, an aliphatic group refers to a group derived from an aliphatic compound. An aliphatic compound is an organic compound or its derivative consisting of a hydrocarbon chain, and can be a saturated or unsaturated compound. Aliphatic compounds include hydrocarbons, aliphatic ethers, aliphatic ketones, etc. An aliphatic group is a group formed by the loss of at least one hydrogen atom in an aliphatic compound, including: groups formed by the loss of at least one hydrogen atom in open-chain hydrocarbons (e.g., alkyl, alkylene); groups formed by the loss of at least one hydrogen atom in cyclic hydrocarbons (i.e., alicyclic groups, such as cycloalkyl, cycloalkylene); groups formed by the loss of at least one hydrogen atom in aliphatic ethers; and groups formed by the loss of at least one hydrogen atom in aliphatic ketones.

[0032] In this application, the alkyl group can be an alkyl group having 1 to 10 carbon atoms, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. Specific examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(CH3)CH2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), and 1-pentyl. (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl-1-butyl (-CH2CH2CH(CH3)2), 2-methyl-1-butyl ( -CH2CH(CH3)CH2CH3), 1-hexyl(-CH2CH2CH2CH2CH2CH3), 2-hexyl(-CH(CH3)CH2CH2CH2CH3), 3-hexyl(-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl(-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl(-CH(CH3)CH(CH3)CH2CH3), 4-methyl-2-pentyl(-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl(-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl(-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl(-C(CH3)2CH(CH3)2), 3,3-dimethyl-2-butyl(-CH(CH3)C(CH3)3 and octyl.

[0033] In this application, cycloalkyl refers to a non-aromatic hydrocarbon containing a ring of carbon atoms, and can be a monocycloalkyl, spirocycloalkyl, or bridged cycloalkyl. The cycloalkyl group can be an alkyl group with 3 to 10 carbon atoms, for example, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. Specific examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. Furthermore, "cycloalkyl" may also contain one or more double bonds; representative examples of cycloalkyl groups containing double bonds include cyclopentenyl, cyclohexenyl, cyclohexadienyl, and cyclobutadienyl.

[0034] In this application, The term "linking bond" refers to a non-positioned linking bond that extends from the ring system. This indicates that one end of the linker can connect to any position in the ring system it traverses, and the other end connects to the rest of the molecule. For example, as shown in equation (Q), the naphthyl group represented by equation (Q) is connected to other positions in the molecule via two non-positional linkers that traverse different benzene rings, representing any possible connection configuration shown in equations (Q-1) to (Q-6):

[0035]

[0036] For another example, as shown in equation (Z), the naphthyl group represented by equation (Z) is connected to other positions in the molecule via a non-positional linker extending from the middle of one side of the benzene ring. This can represent any of the connection methods shown in equations (Z-1) and (Z-2):

[0037]

[0038] In this application, a non-orienting substituent refers to a substituent connected by a single bond extending from the center of the ring system, indicating that the substituent can be attached to any possible position in the ring system. For example, as shown in the following formula (E), the substituent R in formula (E) is connected to the naphthalene ring by a non-orienting linking bond, which means that it includes any of the possible connection methods shown in formulas (E-1) to (E-14):

[0039]

[0040] The first aspect of this application provides a photoresist comprising a polyamic acid-polyamide ester resin, an alkaline catalyst, a crosslinking agent, a coupling agent, a photoresist, and a first organic solvent.

[0041] In this application, the polyamic acid-polyamide ester resin has the structure shown in Formula 1:

[0042]

[0043] n represents the degree of aggregation, n≥10;

[0044] M represents a repeating unit, which includes at least one of the structural units 1 shown in Equation A and at least one of the structural units 2 shown in Equation B:

[0045]

[0046] in, Indicates the connection key.

[0047] X1 and X2 may be the same or different, and each is an independent group containing an alicyclic group and / or an aromatic group;

[0048] Y1 and Y2 may be the same or different, and each is an independent group containing an aliphatic group and / or an aromatic group;

[0049] p is an integer not less than 1.

[0050] Each R may be the same or different, and each is independently a hydrogen or an alkyl group having 1 to 4 carbon atoms.

[0051] In some implementations, the value of n ranges from 10 to 200.

[0052] In some embodiments, each R is independently hydrogen, methyl, ethyl, n-propyl, isopropyl, 1-butyl, 2-methyl-1-propyl, 2-butyl, or 2-methyl-2-propyl.

[0053] In some embodiments, X1 and X2 may be the same or different, and each is independently a group W that is substituted or unsubstituted by at least one substituent S1, wherein group W is selected from any of the following groups:

[0054]

[0055] Indicates a connecting bond. X1, X2, X3, X4, X5, X6, X7, X8, and X9 may be the same or different, and each is independently selected from a single bond, -O-, -S-, -C(CF3)2-, -C(O)-, -SO2-, -N(R1)-, or -C(R2R3)-. R1, R2, and R3 may be the same or different, and each is independently selected from hydrogen or phenyl.

[0056] In X1 and X2, each substituent S1 may be the same or different, and each is independently selected from methyl, trifluoromethyl (-CF3), halogen (such as -F, -Cl or -Br), mercapto or phenyl.

[0057] Preferably, X1 and X2 may be the same or different, and each is independently any one of the following groups:

[0058]

[0059] In some embodiments, Y1 can be a diamine residue having one or more hydroxyl groups. p is, for example, 1 or 2. When p is 1, Y1 is a trivalent group, i.e., -(OH)p is -OH; when p is 2, Y1 is a tetravalent group, i.e., Y1 is attached to two -OH groups. The total number of carbon atoms in Y1 can be 5 to 30.

[0060] In some embodiments, Y1 and Y2 may be the same or different, and each is independently a group V that is substituted or unsubstituted by at least one substituent S2, wherein group V is selected from any of the following groups:

[0061]

[0062] Indicates a connection key, X 10 X 11 X 12 X 13 X 14 X 15 X 16 X 17 X 18 X 19 and X 20 They may be the same or different, and each is independently selected from single bond, -O-, -S-, -C(CF3)2-, -C(O)-, -CH2-, -CH2C(O)-, -SO2-, -N(R4)- or -C(R5R6)-, where R4, R5 and R6 may be the same or different, and each is independently selected from hydrogen or phenyl;

[0063] In Y1 and Y2, each substituent S2 is independently selected from methyl, trifluoromethyl, halogen (such as -F, -Cl or -Br), mercapto, phenyl or aldehyde;

[0064] n1 represents an integer from 1 to 5, specifically 1, 2, 3, 4, or 5.

[0065] It should be understood that in Y1, the two connecting bonds on group V Indicates -(OH) p The connection is outside of the part.

[0066] Preferably, Choose from any of the following structures:

[0067]

[0068] Preferably, Y2 is selected from any one of the following groups:

[0069]

[0070] In this application, the weight-average molecular weight (M) of the polyamic acid-polyamide ester resin is... w The weight-average molecular weight (MAM) is 5000–100000. To further improve the mechanical properties of the cured film while ensuring processing performance, the MAM-polyamide resin preferably has a MAM of 20000–60000. The MAM can be determined by gel permeation chromatography (GPC).

[0071] In this application, the repeating unit M of the polyamic acid-polyamide ester resin may have one or more structural units 1 as shown in formula A. When there are multiple structural units 1, at least one of the corresponding X1, Y1, p and R may be different.

[0072] According to one specific embodiment, the polyamic acid-polyamide ester resin is prepared by a method comprising the following steps:

[0073] 1) In the presence of a second organic solvent, tetracarboxylic anhydride and diamine monomer undergo a polycondensation reaction to obtain a resin precursor, namely polyamic acid;

[0074] 2) The polyamic acid is reacted with an esterification agent to obtain a polycondensation product having the structural unit shown in Formula 1.

[0075] Optionally, the structure of the tetracarboxylic anhydride monomer is shown in Formula 1-1.

[0076]

[0077] The definition of X is the same as that of X1 and X2 mentioned above.

[0078] The diamine monomer includes diamine monomer I and optional diamine monomer II. Diamine monomer I refers to a monomer that simultaneously possesses both a hydroxyl group and an amino group, with the structure shown in Formula 2-1. Diamine monomer II refers to other diamines that do not possess a hydroxyl group, with the structure shown in Formula 2-2.

[0079]

[0080] H2N-Y2-NH2 Equation 2-2

[0081] The definitions of Y1 and Y2 are the same as above.

[0082] Preferably, the tetracarboxylic anhydride is selected from one or more of 4,4'-diphenyl ether dianhydride (ODPA), pyromellitic dianhydride (PMDA), biphenyl dianhydride (BPDA), and 4,4'-(hexafluoroisopropene) phthalic anhydride (6FDA).

[0083] Preferably, the diamine monomer I is selected from one or more of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (BAHF), 2,2-bis(4-hydroxy-3-aminophenyl)propane (BAP), and 3,3'-dihydroxybenzidine (HAB).

[0084] Preferably, the diamine monomer II is selected from 4,4'-diaminodiphenyl ether (ODA) and / or 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB).

[0085] Preferably, the esterification reagent is selected from one or more of N',N-dimethylformamide dimethyl acetal, N,N-dimethylformamide diethyl acetal, N,N-dimethylformamide dipropyl acetal, N,N-dimethylformamide diisopropyl acetal, and N,N-dimethylformamide dibutyl acetal.

[0086] In step 1), the reaction temperature in the polycondensation reaction can be -10℃ to 50℃, the reaction time can be 6 to 72h, and the second organic solvent can be selected from one or more of N,N'-dimethylacetamide (DMAC), N,N'-dimethylacetamide (DMF), γ-butyrolactone (γ-GBL), and N-methylpyrrolidone (NMP).

[0087] In step 2), the reaction temperature of the esterification reaction can be 40–70°C, and the reaction time can be 0.5–4 h.

[0088] The molar ratio of the tetracarboxylic anhydride, diamine monomer, and esterification reagent can be 1:(0.9-1.1):(0.8-2.2).

[0089] In this application, the alkaline catalyst is selected from DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) salt latent catalyst and / or DBN (1,5-diazabicyclo[4.3.0]non-5-ene) salt latent catalyst. "Lateness" refers to the catalyst's lack of catalytic activity at low temperatures, with a significant increase in catalytic effect as the temperature rises. The alkaline catalyst exhibits low catalytic activity and weak alkalinity at low temperatures, which is beneficial for maintaining resin stability and reducing resin degradation. Simultaneously, it possesses high activity at high temperatures, enabling efficient (>95%) imidization of the polyimide resin with a smaller dosage at a lower temperature (approximately 200°C).

[0090] Preferably, the alkaline catalyst is selected from one or more of DBU formate, DBU oleate, DBU octanoate, DBU phenolate, DBU benzenesulfonate, DBN formate, DBN oleate, DBN octanoate, DBN phenolate, and DBN benzenesulfonate. In this case, the alkaline catalyst is readily available and has high storage stability.

[0091] The aforementioned DBU and DBN salts are commercially available or prepared using methods well-known in the art. For example, the corresponding acid can be added to DBU or DBN and reacted with stirring at room temperature (25°C) or under heating for 1–3 hours to obtain the DBU or DBN salt. When preparing DBU salts, the molar ratio of acid to DBU can be 1:(0.9–1), for example, 1:1. Similarly, when preparing DBN salts, the molar ratio of acid to DBN can be 1:(0.9–1), for example, 1:1.

[0092] In this application, the content of the alkaline catalyst in the photoresist can be 0.1 to 5 parts by weight relative to 100 parts by weight of the polyamic acid-polyamide ester resin. To further prevent resin degradation and reduced storage stability while ensuring a high degree of amidation of the resin, preferably, the content of the alkaline catalyst is 0.8 to 3 parts by weight relative to 100 parts by weight of the polyamic acid-polyamide ester resin.

[0093] In this application, the crosslinking agent can be a compound having unsaturated double bond functional groups such as vinyl, allyl, acryloyl, and methacryloyl, and / or unsaturated triple bond functional groups such as propyne, preferably a compound containing conjugated vinyl, acryloyl, or methacryloyl groups. At the curing temperature, the aforementioned unsaturated functional groups can react with the hydroxyl groups on the polyamic acid-polyamide ester resin molecular chain to form a crosslinked structure, thereby improving the mechanical properties of the resin. The crosslinking agent preferably has 1 to 6 active functional groups. Terminal alkenyl groups are, for example, vinyl, allyl, acryloyl, and methacryloyl groups.

[0094] In some embodiments, the crosslinking agent is selected from one or more of bisphenol A epoxy diacrylate (CAS: 89297-97-2), dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, N-vinylpyrrolidone, isobornyl acrylate, and N-vinylcaprolactam.

[0095] Preferably, the crosslinking agent is bisphenol A epoxy diacrylate and dipentaerythritol hexaacrylate, which can further improve the mechanical strength of the formed cured film. More preferably, the mass ratio of bisphenol A epoxy diacrylate to dipentaerythritol hexaacrylate is 30:(1-6).

[0096] In the photoresist, the crosslinking agent can be 5 to 20 parts by weight, preferably 5 to 15 parts by weight, relative to 100 parts by weight of the polyamic acid-polyamide ester resin.

[0097] In this application, introducing a coupling agent into the photoresist can effectively improve the adhesion performance of the photoresist cured film to the substrate. The coupling agent can be a compound having an alkoxysilyl group and at least one group selected from epoxy, oxetyl, methacryloxy, acryloyloxy, and vinyl groups. In some embodiments, the coupling agent is selected from one or more of aminopropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, epoxybutyltrimethoxysilane, vinyltrimethoxysilane, p-styryltrimethoxysilane (CAS No.: 18001-13-3), and vinyltriethoxysilane.

[0098] In the photoresist, the coupling agent may be 1 to 5 parts by weight relative to 100 parts by weight of the polyamic acid-polyamide ester resin.

[0099] In this application, the photoresist can be selected from existing photoacid-generating agents. In some embodiments, the photoresist is selected from one or more of diazononaphthoquinone compounds (DNQ), sulfonium salts, phosphonium salts, diazonium salts, iodide salts, and trifluoromethanesulfonate compounds (e.g., iodine diphenyltrifluoromethanesulfonate). Preferably, the photoresist is 2,3,4-trihydroxybenzophenone-2,1,5-diazonaphthoquinone sulfonate (CAS No.: 68510-93-0), which enables the photoresist to exhibit excellent dissolution inhibition and improve sensitivity.

[0100] In the photoresist, the photoresist may be 15 to 30 parts by weight relative to 100 parts by weight of the polyamic acid-polyamide ester resin.

[0101] In this application, the first organic solvent may be selected with reference to existing photoresists. In some embodiments, the first organic solvent is selected from one or more of γ-butyrolactone (γ-GBL), N-methylpyrrolidone (NMP), N,N-dimethylacetamide (DMAc), ethylene glycol monomethyl ether (EGME), ethyl lactate (EL), and methyl ethyl ketone (MEK).

[0102] In the photoresist, the first organic solvent is 500 to 2000 parts by weight relative to 100 parts by weight of the polyamic acid-polyamide ester resin.

[0103] According to one embodiment, the photoresist is obtained by mixing the polyamic acid-polyamide ester resin, an alkaline catalyst, a crosslinking agent, a coupling agent, and a first organic solvent, and then stirring at room temperature (15-25°C) for 24-72 hours.

[0104] The second aspect of this application provides a photoresist-cured film, formed by curing the photoresist described in the first aspect of this application. At a curing temperature (not lower than 200°C), the polyamic acid-polyamide ester resin in the photoresist is imidized under the action of an alkaline catalyst to obtain an imidized product having one or more structural units shown in Formula 1A. The hydroxyl groups on the polyimide undergo a crosslinking reaction with a crosslinking agent to form a cured film with high mechanical strength.

[0105]

[0106] The photoresist-formed cured film described in this application can be used as a passivation film for semiconductors, a protective film for semiconductor devices, an interlayer insulating film for multilayer wiring in high-density mounting, and an insulating layer for organic light-emitting devices, etc.

[0107] A third aspect of this application provides a method for patterning photoresist, the method comprising: coating the photoresist described in the first aspect of this application onto a substrate, and sequentially subjecting it to pre-baking, exposure, development and curing to form a cured film pattern layer on the substrate.

[0108] According to the method of this application, the substrate is, for example, a silicon wafer, ceramic, metal, glass, silicon nitride, or ITO.

[0109] According to the method of this application, the temperature for pre-baking the substrate coated with the photoresist can be 90–150°C, and the pre-baking time can be 1–30 minutes. The pre-baked coating is then exposed to photochemical rays (e.g., i-lines, g-lines) through a mask with the desired pattern.

[0110] According to the method of this application, a pattern can be formed by removing the exposed portion using a developing solution. The developing solution is an alkaline developing solution. In some embodiments, the developing solution is an aqueous solution of an alkali selected from at least one of tetramethylammonium hydroxide (TMAH), sodium hydroxide (NaOH), potassium hydroxide (KOH), and triethylamine (Et3N), wherein the mass concentration of the alkali in the alkaline developing solution is 2-5%. In one specific embodiment, the alkaline developing solution is an aqueous solution of TMAH with a mass concentration of 2.38%.

[0111] According to the method of this application, after development, the coating film can be converted into a cured film through curing. While ensuring resin imidization, a lower curing temperature is more conducive to suppressing film warping. Preferably, the curing temperature is 200–250°C, and the curing time is 0.5–1.5 h.

[0112] The patterning method of this application can achieve imidization of resin at a lower temperature, and the resulting patterned layer has high mechanical strength and adhesion properties, meeting the encapsulation requirements.

[0113] The following synthesis examples illustrate polyamic acid-polyamide ester resins and their preparation methods.

[0114] Synthesis example 1

[0115] 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (BAHF, 27.47 g, 75 mmol) and anhydrous N,N'-dimethylacetamide (DMAC, 100 mL) were added to a 500 mL three-necked flask. The mixture was stirred at room temperature until BAHF dissolved. Then, 4,4'-biphenyl ether dianhydride (ODPA, 23.27 g, 75 mmol) was added, and the mixture was cooled to -4 °C and stirred for 8 h to obtain a polyamic acid solution. N',N-dimethylformamide dimethyl acetal (DMFDMA, 17.87 g, 150 mmol) dissolved in 20 mL of DMAC was added to this solution. The mixture was heated to 50 °C and reacted for 0.5 h. The reaction system was then cooled to room temperature, poured into water to produce a precipitate, dispersed, and filtered. The resulting solid was dried under vacuum at 50 °C to obtain polyamic acid-polyamide ester resin A with a weight-average molecular weight of 47,000. The synthetic route of this resin is shown below:

[0116]

[0117] Synthesis example 2

[0118] 2,2-bis(4-hydroxy-3-aminophenyl)propane (BAP, 19.37 g, 75 mmol) and 4,4'-diaminodiphenyl ether (ODA, 5.01 g, 25 mmol) and anhydrous N-methylpyrrolidone (NMP, 120 mL) were added to a 500 mL three-necked flask. The mixture was stirred at room temperature until the diamine dissolved. Then, 4,4'-biphenyl ether dianhydride (ODPA, 23.27 g, 75 mmol) and pyromellitic dianhydride (PMDA, 5.45 g, 25 mmol) were added, and the mixture was stirred at room temperature for 18 h to obtain a polyamic acid solution. A solution dissolved in 20 mL of [unspecified substance] was then added to this solution. NMP's N',N-dimethylformamide diethyl acetal (DMFDEA, 23.55 g, 160 mmol) was heated to 50 °C and reacted for 1 h. The reaction system was then cooled to room temperature, poured into water to produce a precipitate, dispersed, and filtered. The resulting solid was dried under vacuum at 50 °C to obtain polyamic acid-polyamide ester resin B with a weight average molecular weight of 51,000.

[0119] Synthesis example 3

[0120] 3,3'-dihydroxybenzidine (HAB, 16.22 g, 75 mmol) and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB, 24.02 g, 75 mmol) and anhydrous DMAC (120 mL) were added to a 500 mL three-necked flask. The mixture was stirred at room temperature until the diamine dissolved. Then, ODPA (46.54 g, 150 mmol) was added and the mixture was stirred at room temperature for 10 h to obtain a polyamic acid solution. DMFDMA (29.78 g, 250 mmol) dissolved in DMAC (30 mL) was added to the solution. The mixture was heated to 50 °C and reacted for 1 h. The reaction system was then cooled to room temperature, poured into water to produce a precipitate, dispersed, and filtered. The resulting solid was dried under vacuum at 50 °C to obtain polyamic acid-polyamide ester resin C with a weight average molecular weight of 49,000.

[0121] Synthesis example 4

[0122] 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (BAHF, 27.47 g, 75 mmol) and anhydrous N,N'-dimethylacetamide (DMAC, 100 mL) were added to a 500 mL three-necked flask. The mixture was stirred at room temperature until the diamine dissolved. Then, PMDA (16.35 g, 75 mmol) was added and the mixture was stirred at room temperature for 8 h to obtain a polyamic acid solution. DMFDMA (17.87 g, 150 mmol) dissolved in DMAC (20 mL) was added to the solution. The mixture was heated to 50 °C and reacted for 0.5 h. The reaction system was then cooled to room temperature and poured into water to produce a precipitate. The precipitate was dispersed and filtered. The resulting solid was dried under vacuum at 50 °C to obtain polyamic acid-polyamide ester resin D with a weight average molecular weight of 56,000.

[0123] Synthesis example 5

[0124] 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (BAHF, 27.47 g, 75 mmol) and 3,3'-dihydroxybenzidine (HAB, 16.22 g, 75 mmol) and DMAC (180 mL) were added to a 500 mL three-necked flask. The mixture was stirred at room temperature until the diamine dissolved. Then, ODPA (46.54 g, 150 mmol) was added and the mixture was stirred at -4 °C for 24 h to obtain a polyamic acid solution. DMFDEA (23.55 g, 160 mmol) dissolved in DMAC (20 mL) was added to the solution. The mixture was heated to 50 °C and reacted for 1 h. The reaction system was then cooled to room temperature, poured into water to produce a precipitate, dispersed, and filtered. The resulting solid was dried under vacuum at 50 °C to obtain polyamic acid-polyamide ester resin E with a weight average molecular weight of 55,000.

[0125] The examples are used to illustrate the photoresist and its preparation method of this application.

[0126] In the following examples and comparative examples,

[0127] 2,3,4-Trihydroxybenzophenone-2,1,5-diazonaphthoquinone sulfonate was purchased from Wuhan Camick Technology Co., Ltd.

[0128] Bisphenol A epoxy diacrylate, dipentaerythritol hexaacrylate, and 1-BOC-2,6-dimethylpiperazine were purchased from ADAMAS.

[0129] Vinyltrimethoxysilane was purchased from TCI.

[0130] DBU formate and DBN formate were purchased from Shanghai Runyi Chemical Technology Co., Ltd.

[0131] Example 1

[0132] Add 4g of polyamic acid-polyamide ester resin A and 1g of 2,3,4-trihydroxybenzophenone-2,1,5-diazonaphthoquinone sulfonate to a black light-proof bottle, then add 10mL of anhydrous γ-butyrolactone and 10mL of ethyl lactate. Stir at room temperature until dissolved, then add 40mg of DBU formate, 200mg of bisphenol A epoxy diacrylate, 30mg of dipentaerythritol hexaacrylate and 40mg of vinyltrimethoxysilane. Continue stirring for 24h to obtain photoresist P1.

[0133] Comparative Example 1

[0134] The photoresist was prepared according to the method of Example 1, except that DBU formate was not added, resulting in photoresist DP1.

[0135] Comparative Example 2

[0136] The photoresist was prepared according to the method of Example 1, except that bisphenol A epoxy diacrylate and dipentaerythritol hexaacrylate were not added, resulting in photoresist DP2.

[0137] Comparative Example 3

[0138] Photoresist was prepared according to the method of Example 1, except that vinyltrimethoxysilane was not added, resulting in photoresist DP3.

[0139] Comparative Example 4-5

[0140] The photoresist was prepared according to the method of Example 1, except that the catalyst DBU formate was replaced with an equal amount of pyridine (16 mg), and the photoresist was divided into two parts, denoted as DP4 and DP5.

[0141] Example 2

[0142] Add 4g of polyamic acid-polyamide ester resin B and 1g of 2,3,4-trihydroxybenzophenone-2,1,5-diazonaphthoquinone sulfonate to a black light-proof bottle, then add 10mL of anhydrous γ-butyrolactone and 10mL of ethyl lactate. Stir at room temperature until dissolved, then add 40mg of DBU formate, 200mg of bisphenol A epoxy diacrylate, 30mg of dipentaerythritol hexaacrylate and 40mg of vinyltrimethoxysilane. Continue stirring for 24h to obtain photoresist P2.

[0143] Example 3

[0144] The photoresist was prepared according to the method of Example 2, except that the catalyst was replaced with an equal amount of DBN formate (33 mg) to obtain photoresist P3.

[0145] Example 4

[0146] Add 4g of polyamic acid-polyamide ester resin C and 1g of 2,3,4-trihydroxybenzophenone-2,1,5-diazonaphthoquinone sulfonate to a black light-proof bottle, then add 10mL of anhydrous γ-butyrolactone and 10mL of ethyl lactate. Stir at room temperature until dissolved, then add 40mg of DBU formate, 200mg of bisphenol A epoxy diacrylate, 40mg of dipentaerythritol hexaacrylate and 40mg of vinyltrimethoxysilane. Continue stirring for 24h to obtain photoresist P4.

[0147] Example 5

[0148] The photoresist was prepared according to the method in Example 4, except that the crosslinking agent was replaced with 240 mg of bisphenol A epoxy diacrylate to obtain photoresist P5.

[0149] Comparative Example 6

[0150] The photoresist was prepared according to the method in Example 4, except that the catalyst was replaced with 1.2 g of 1-BOC-2,6-dimethylpiperazine to obtain photoresist DP6.

[0151] Example 6

[0152] Add 4g of polyamic acid-polyamide ester resin D and 1g of 2,3,4-trihydroxybenzophenone-2,1,5-diazonaphthoquinone sulfonate to a black light-proof bottle, then add 10mL of anhydrous γ-butyrolactone and 10mL of ethyl lactate. Stir at room temperature until dissolved, then add 40mg of DBU formate, 200mg of bisphenol A epoxy diacrylate, 30mg of dipentaerythritol hexaacrylate and 40mg of vinyltrimethoxysilane. Continue stirring for 24h to obtain photoresist P6.

[0153] Example 7

[0154] Add 4g of polyamic acid-polyamide ester resin E and 1g of 2,3,4-trihydroxybenzophenone-2,1,5-diazonaphthoquinone sulfonate to a black light-proof bottle, then add 10mL of anhydrous γ-butyrolactone and 10mL of ethyl lactate. Stir at room temperature until dissolved, then add 40mg of DBU formate, 200mg of bisphenol A epoxy diacrylate, 30mg of dipentaerythritol hexaacrylate and 40mg of vinyltrimethoxysilane. Continue stirring for 24h to obtain photoresist P7.

[0155] Test Example 1

[0156] This test example is used to test the degree of imidization of polyamic acid-polyamide ester resin.

[0157] A mixture of polyamic acid-polyamide ester resin A and DBU formate (1% wt) was spin-coated onto a 4-inch silicon wafer using a spin coater and then softened at 120°C for 3 minutes to produce a film with a thickness of 10 mm ± 1 mm. This film was divided into two portions. One portion was placed in a nitrogen oven and heated to 350°C at a rate of 10°C / min, held at that temperature for 60 minutes, and then cooled to room temperature to obtain cured film A. The other portion was placed in a nitrogen oven and heated to 200°C at a rate of 10°C / min, held at that temperature for 60 minutes, and then cooled to room temperature to obtain cured film B.

[0158] Infrared absorption spectra were measured using a Thermo Fisher Scientific Nicolet iS5 Fourier transform infrared spectrometer. The infrared spectra are shown below. Figure 1 and Figure 2 As shown. Comparison of cured film A and cured film B at 1377 cm⁻¹ of the imide ring. -1 The absorption peak intensity at point B is used, and the ratio of the peak intensity of cured film B to the peak intensity of cured film A is taken as the degree of imidization. Figure 1 and Figure 2 It can be seen that the curing temperature of polyamic acid-polyamide ester A is significantly reduced after adding DBU formate, and the degree of imidization can reach more than 99% after curing at 200℃ for 1 hour.

[0159] The following test examples 2 and 3 are used to illustrate the performance of the cured film formed by the photoresist. The photoresist was filtered through a 0.22 μm filter before use.

[0160] Test Example 2

[0161] This test case is used to test the warpage of photoresist.

[0162] Photoresist P1 to P7 and DP1 to DP6 were coated onto a 4-inch silicon wafer using a spin coater. The wafer was then softened at 120°C for 3 minutes to produce a film with a thickness of 10μm±1μm. The film was then placed in a nitrogen oven and heated to 200°C at a rate of 10°C / min, and held at that temperature for 60 minutes. After cooling to room temperature, the film was removed to obtain a cured film.

[0163] The residual stress of the cured film was measured using a KLATencor FLX2908 pressure device. Residual stress above 35 MPa was considered unacceptable (D), residual stress between 30 MPa and 35 MPa was considered acceptable (C), residual stress between 20 MPa and 30 MPa (excluding 30 MPa) was considered good (B), and residual stress below 20 MPa was considered excellent (A). The test results are shown in Table 1.

[0164] Test Example 3

[0165] This test case is used to test the mechanical properties of photoresist.

[0166] Photoresists P1 to P7 and DP1 to DP4 and DP6 were spin-coated onto an 8-inch silicon wafer using a spin coater. After soft baking at 120°C for 3 minutes, a film with a thickness of 30μm ± 1μm was prepared. The film was then placed in a nitrogen oven, heated to 200°C at a rate of 10°C / min, and held at that temperature for 60 minutes. After cooling to room temperature, the film was cured. Photoresist DP5 was cured using the same method, except that after soft baking, the film was placed in a nitrogen oven, heated to 350°C at a rate of 10°C / min, and held at that temperature for 60 minutes. The cured film was cut into 10mm wide strips, and the Young's modulus (Et) and elongation at break (ε) were tested using a Zwick electronic universal testing machine according to GB / T1843 standard. m The test results are shown in Table 1.

[0167] Application examples

[0168] The photoresists P1 to P7 and DP1 to DP6 were spin-coated onto the surface of a silicon wafer (Jingxin Electronics Technology Co., Ltd.). The wafer was pre-baked at 120°C for 3 minutes, and then placed on an i-line photolithography machine for photolithography at an exposure energy of 200 mJ / cm². 2 The silicon wafer is then immersed in a 2.38% tetramethylammonium hydroxide aqueous solution for 40 seconds for development, then cleaned with ultrapure water, and finally cured at 200°C for 60 minutes.

[0169] The patterning effect on the coated silicon wafer was observed by scanning electron microscopy, and the highest resolution results (rounded to the nearest integer) are shown in Table 1.

[0170] Table 1

[0171] serial number Photoresist Et / GPa <![CDATA[ε m / %]]> Warp Resolution / μm Example 1 P1 2.81 13 A 3 Comparative Example 1 DP1 / / / 3 Comparative Example 2 DP2 2.54 6.2 C 5 Comparative Example 3 DP3 2.77 10 B 5 Comparative Example 4 DP4 / / / 3 Comparative Example 5 DP5 3.01 15 C 3 Example 2 P2 2.99 14 A 3 Example 3 P3 2.93 13 A 3 Example 4 P4 2.79 12 A 3 Example 5 P5 2.69 9.7 A 4 Comparative Example 6 DP6 2.61 6.9 B 3 Example 6 P6 3.11 11 A 4 Example 7 P7 2.88 12 A 3

[0172] The curing temperature of photoresists DP1 and DP4 is 200℃, and the cured film cracked during mechanical property testing; the maximum curing temperature of photoresist DP5 is 350℃.

[0173] As shown in Table 1, the photoresist provided in this application achieves a high degree of imidization and crosslinking at lower temperatures, resulting in a cured film with high mechanical and adhesive properties, and suppressing warpage. Furthermore, the photolithographic patterning results of photoresist P1 are as follows... Figure 3 As shown, by Figure 3 It is known that the P1 photoresist has a resolution of about 3μm, complete patterns, high contrast, and a nearly vertical cone angle, which is beneficial for its application in the chip industry.

[0174] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0175] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A photoresist, characterized in that, The mixture comprises a polyamic acid-polyamide ester resin, a basic catalyst, a crosslinking agent, a coupling agent, a photoresist, and a first organic solvent, wherein the polyamic acid-polyamide ester resin has the structure shown in Formula 1: Formula 1 In Equation 1, n ≥ 10; M includes at least one of the structural unit 1 shown in Formula A and at least one of the optional structural unit 2 shown in Formula B: Formula A Formula B " " indicates a connection key. X1 and X2 may be the same or different, and each is an independent group containing an alicyclic group and / or an aromatic group; Y1 and Y2 may be the same or different, and each is independently a group containing an aliphatic group and / or an aromatic group; p is an integer not less than 1; Each R may be the same or different, and each is independently a hydrogen or an alkyl group having 1 to 4 carbon atoms; The weight-average molecular weight of the polyamic acid-polyamide ester resin is 5,000 to 100,000. Furthermore, the polyamic acid-polyamide ester resin is prepared by a method comprising the following steps: In the presence of a second organic solvent, a tetracarboxylic anhydride and a diamine monomer are subjected to a polycondensation reaction to obtain a resin precursor; the resin precursor is then reacted with an esterification reagent; the tetracarboxylic anhydride is selected from one or two of 4,4'-biphenyl ether dianhydride and pyromellitic dianhydride; the diamine monomer includes diamine monomer I and diamine monomer II; diamine monomer I is selected from one or more of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 2,2-bis(4-hydroxy-3-aminophenyl)propane, and 3,3'-dihydroxybenzidine; diamine monomer II is selected from 4,4'-diaminodiphenyl ether and / or 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl; The crosslinking agent is a mixture of bisphenol A epoxy diacrylate and dipentaerythritol hexaacrylate; The alkaline catalyst is a DBU salt latent catalyst and / or a DBN salt latent catalyst.

2. The photoresist according to claim 1, characterized in that, The coupling agent is selected from one or more of aminopropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, epoxybutyltrimethoxysilane, vinyltrimethoxysilane, p-styryltrimethoxysilane, and vinyltriethoxysilane.

3. The photoresist according to claim 1, characterized in that, The first organic solvent is selected from one or more of γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylacetamide, ethylene glycol monomethyl ether, ethyl lactate and methyl ethyl ketone.

4. The photoresist according to claim 1, characterized in that, The photoresist is selected from one or more of the following: diazonoquinone compounds, sulfonium salts, phosphonium salts, diazonium salts, iodine salts, and trifluoromethanesulfonate compounds.

5. The photoresist according to claim 1, characterized in that, In the crosslinking agent, the mass ratio of bisphenol A epoxy diacrylate to bispentaerythritol hexaacrylate is 30:(1-6).

6. The photoresist according to claim 1, characterized in that, The alkaline catalyst is selected from one or both of DBU formate and DBN formate.

7. The photoresist according to any one of claims 1-6, characterized in that, In the photoresist, relative to 100 parts by weight of the polyamic acid-polyamide ester resin, the photoresist is 15 to 30 parts by weight, the alkaline catalyst is 0.1 to 5 parts by weight, the crosslinking agent is 5 to 20 parts by weight, the coupling agent is 1 to 5 parts by weight, and the first organic solvent is 500 to 2000 parts by weight.

8. A photoresist-cured film, characterized in that, It is formed by curing the photoresist according to any one of claims 1-7.

9. A method for patterning photoresist, characterized in that, Includes the following steps: The photoresist according to any one of claims 1-7 is coated on a substrate and then subjected to pre-baking, exposure, development and curing in sequence to form a cured film pattern layer on the substrate.

10. The patterning method according to claim 9, characterized in that, The patterning method has the following features (1) and / or (2): (1) The developing solution used is an aqueous solution of an alkali, wherein the alkali is selected from at least one of tetramethylammonium hydroxide, sodium hydroxide, potassium hydroxide and triethylamine, and the mass concentration of the alkali in the developing solution is 2-5%; (2) The curing temperature is 200-250℃ and the curing time is 0.5-1.5h.

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