Matrix resin, photoresist composition, photoresist, preparation method and application thereof

Abstract

The present invention provides a kind of matrix resin, photoresist composition, photoresist and its preparation method and application, belong to the field of photoresist technology.The matrix resin is synthesized by polymerization reaction of styrene, p-phenoxystyrene, and p-(epoxyethyl)styrene, with a weight average molecular weight range of 2000-50000, an oxygen element weight content of 1%-1.5%, and an epoxy value of 0.2-0.8mmol / g.The matrix resin provided by the present invention can participate in the formation of a kind of photoresist, and by the catalytic reaction of epoxy groups and phenolic hydroxyl groups, the cross-linking degree after light excitation can be further improved, adhesion is improved, and then a more refined photolithography process is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of photoresists and relates to a matrix resin, a photoresist composition, a photoresist and a preparation method and application thereof. Background Art

[0002] The quality of integrated circuit chips is directly determined by the level of photolithography technology. Photolithography involves exposing a photoresist to a specific light source. Then, through steps like development and etching, the pre-designed pattern on the mask is transferred to the substrate wafer. The creation of a high-performance integrated circuit chip requires not only innovative design but also advanced photolithography technology. Photoresist is a light-sensitive material. During the exposure process (e.g., ultraviolet radiation), certain chemical reactions occur, causing the exposed areas to change their solubility in the developer. After development with the developer, a specific photolithographic pattern consisting of components and circuits is obtained. Photoresist primarily consists of four parts: a film-forming resin, a photosensitive substance, a solvent, and appropriate additives. The film-forming resin is the primary component of the photoresist, providing support for the entire photoresist and imparting its etching resistance, significantly impacting its performance.

[0003] Photoresists are complex to prepare and come in a wide variety of types. They can be divided into two categories based on their solubility in developer before and after exposure: positive-tone and negative-tone. A chemical reaction in the exposed areas of a positive-tone photoresist increases its solubility in the developer, leaving the masked areas after development as the designed chip pattern. Conversely, a chemical reaction in the exposed areas of a negative-tone photoresist decreases its solubility in the developer, leaving the masked areas soluble in the developer, resulting in a chip pattern that complements the mask.

[0004] Chinese patent application 200780029153.7 discloses a photoresist composition having ideal physical properties such as photosensitivity, resolution, residual film ratio, and coating characteristics. Furthermore, due to its excellent light transmittance, it can be used in semiconductor or flat panel display processes to form patterns with ideal development profiles and depth of focus using a light source with a wavelength of 248 nm (krypton fluoride, KrF) or shorter, even when the photoresist composition is used in non-chemically amplified photoresists.

[0005] Chinese patent application 202111515560.7 discloses a method for forming a photoresist pattern and a photoresist structure. The method for forming a photoresist pattern includes forming a photoresist structure on a target layer, the photoresist structure including a photoresist layer disposed on the target layer and a light wave transmission layer disposed on the photoresist layer; exposing the photoresist structure in a first medium to form an exposure image on the photoresist layer, and the light wave transmission layer is used to improve the photolithographic resolution of the photoresist layer. The method for forming a photoresist pattern in this technology improves the resolution of the exposure image through the light wave transmission layer, thereby improving the accuracy of the photoresist pattern.

[0006] However, the prior art cannot provide a photoresist composition that can achieve a more sophisticated photolithography process. Summary of the Invention

[0007] In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a matrix resin, a photoresist composition, a photoresist and a preparation method and application thereof.

[0008] To achieve the above-mentioned object of the invention, on the one hand, the present invention provides a base resin, wherein the structural units of the base resin are composed of the following groups:

[0009]

[0010] Preferably, the weight average molecular weight of the matrix resin is in the range of 2000-50000, more preferably 3000-30000, and even more preferably 20000-25000. More preferably, the weight average molecular weight is 23097-23497.

[0011] Preferably, the polymer dispersibility index (PDI) of the matrix resin is 1 to 5, more preferably 1 to 3. Further preferably, the PDI is 1.98 to 2.12.

[0012] The polymer dispersibility index (PDI) is defined as the ratio of the weight average molecular weight to the number average molecular weight of a polymer.

[0013] Preferably, the weight content of oxygen in the matrix resin is 1%-1.5%, more preferably 1.35%-1.37%.

[0014] Preferably, the epoxy value of the base resin is 0.2-0.8 mmol / g.

[0015] In another aspect, the present invention provides a method for preparing a matrix resin, comprising the following steps:

[0016] Styrene, p-phenoxystyrene, p-(epoxyethyl)styrene, a solvent and an initiator are mixed and heated for reaction to obtain a base resin.

[0017] Wherein, the chemical structural formula of the p-phenoxystyrene is as follows:

[0018]

[0019] The chemical structural formula of described p-(ethylene oxide) styrene is as follows:

[0020]

[0021] Preferably, the ratio of the solvent to the styrene is 1:0.8-1.2, more preferably 1:1, and the unit is L:mol.

[0022] Preferably, the initiator is an azo initiator, including but not limited to azobisisobutyronitrile, azobisisoheptanenitrile, azobisisobutylimidazoline hydrochloride, azobisisobutylamidine hydrochloride, azoisobutylcyanamide and dimethyl azobisisobutyrate.

[0023] More preferably, and as a specific example of the present invention, the initiator is azobisisoheptanonitrile.

[0024] Preferably, the molar ratio of styrene, p-phenoxystyrene and p-(ethylene oxide)styrene is 100:2.4-6.4:5.6-9.6. More preferably, and as a specific example of the present invention, the molar ratio of styrene, p-phenoxystyrene and p-(ethylene oxide)styrene is 100:4.4:7.6.

[0025] Preferably, the weight of the initiator is 0.5%-10% of the total weight of the styrene, p-phenoxystyrene, and p-(ethylene oxide)styrene. More preferably, and as a specific embodiment of the present invention, the weight of the initiator is 3% of the total weight of the styrene, p-phenoxystyrene, and p-(ethylene oxide)styrene.

[0026] Preferably, the solvent is selected from at least one of toluene, xylene, diphenyl ether, dimethyl sulfoxide, ethyl acetate, and ethyl lactate, more preferably ethyl acetate.

[0027] Preferably, the temperature of the heating reaction is 50-90°C, more preferably 60-80°C.

[0028] Preferably, the heating reaction time is 6-30 hours, more preferably 8-20 hours, and even more preferably 8-15 hours.

[0029] On the other hand, the present invention provides a photoresist composition comprising, by weight, 141-176 parts of a base resin, 29-64 parts of poly(4-vinylphenol), 6-10 parts of an acid generator, and 2000-2800 parts of an organic solvent;

[0030] Wherein, the base resin is the base resin prepared by the above-mentioned preparation method.

[0031] Preferably, the acid generator is a photoacid generator.

[0032] More preferably, the photoacid generator is at least one selected from the group consisting of sulfonium salt acid generators, iodonium salt acid generators, diazomethane acid generators, and nitrobenzene sulfonate acid generators.

[0033] As an example of the present invention, the acid generator is diphenyliodonium hexafluorophosphate.

[0034] Preferably, and as an example of the present invention, the photoresist composition further comprises 5.1-24 parts by weight of a crosslinker; the crosslinker is selected from at least one of an etherified amino crosslinker and an etherified polyphenyl crosslinker.

[0035] More preferably, the etherified amino cross-linking agent is selected from etherified melamine cross-linking agents and etherified urea cross-linking agents.

[0036] More preferably, the etherified melamine cross-linking agent is Cymel 308.

[0037] More preferably, the etherified urea crosslinking agent is selected from at least one of 1,3-dimethoxymethyl-4,5-dimethoxyethylene urea, 1,3,4,6-tetrakis(methoxymethyl)glycoluril (TMMG), and 1,3-dimethoxy-1,3-dimethylurea.

[0038] More preferably, the etherified polyphenyl crosslinking agent is at least one selected from 4,4′-(2,2-dipropyl)bis(2,6-bis(methoxymethyl)phenol) and 4,4′,4″-(1,1,1-triethyl)tris(2,6-bis(methoxymethyl)phenol).

[0039] As an embodiment of the present invention, the cross-linking agent is 1,3,4,6-tetrakis(methoxymethyl)glycoluril. Its structural formula is:

[0040]

[0041] Preferably, the solvent is selected from at least one of alcohols, esters, ethers, aromatic hydrocarbons and ketones.

[0042] More preferably, the solvent is selected from at least one of propylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, n-hexanol, n-butanol, isopropyl alcohol, and diphenyl ether.

[0043] More preferably, the solvent is a mixture of propylene glycol monomethyl ether acetate and diphenyl ether.

[0044] Further preferably, and as an example of the present invention, the solvent is a mixture of propylene glycol monomethyl ether acetate and diphenyl ether in a volume ratio of 1:1.

[0045] Preferably, the photoresist composition further comprises 3-7 parts by weight of a photobase generator.

[0046] The photobase generator is selected from at least one of the following ingredients:

[0047]

[0048] More preferably, the photobase generator is selected from one of the following ingredients:

[0049]

[0050] More preferably, and as an example of the present invention, the photobase generator is

[0051]

[0052] Preferably, the photoresist composition further comprises 0.001-5 parts by weight of an additive.

[0053] The additive is selected from one or more of a stabilizer, a leveling agent, and a surfactant.

[0054] In another aspect, the present invention provides a photoresist made from the above-mentioned photoresist composition, preferably made from a mixture of the above-mentioned photoresist compositions.

[0055] The present invention has no particular limitation on the order of mixing the components in the above-mentioned photoresist composition, as long as the purpose of the present invention can be achieved.

[0056] On the other hand, the present invention provides the use of the above-mentioned photoresist in forming a photoresist pattern, including a film forming process, an exposure process and a development process.

[0057] Preferably, the exposure is performed using a KrF laser.

[0058] Preferably, the application comprises the following steps:

[0059] S1, coating a photoresist on a substrate to obtain a coated backplane;

[0060] S2, coating the coated board obtained in step S1 with glue and then baking it at a temperature of 90-130° C. for 60-120 seconds to obtain a PEB board;

[0061] S3, exposure: the PEB board obtained in step S2 is exposed using a KrF exposure machine to obtain an exposed board;

[0062] S4, performing post-exposure baking on the exposed board obtained in step S3 at a temperature of 110-140° C. for 60-120 seconds to obtain a PAB board;

[0063] S5, development: the PAB board obtained in step S4 is developed using a developer to obtain a circuit substrate product.

[0064] Preferably, in step S5, the developer is an aqueous solution of at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide.

[0065] In the final aspect, the present invention provides the use of the above-mentioned base resin or the base resin prepared by the preparation method, or the above-mentioned photoresist composition, or the above-mentioned photoresist in the preparation of circuit substrates and integrated circuit boards.

[0066] Equivalent to the prior art, the present invention has the following beneficial effects:

[0067] 1. The present invention provides a photoresist composition comprising a polymer component containing hydroxyl and epoxy groups. When the photoresist composition is exposed to KrF excited-state laser irradiation, a photoacid generator absorbs light energy and decomposes to produce acid. During post-exposure baking, the acid causes a ring-opening polymerization reaction between the epoxy groups, crosslinking the polymer chains. Furthermore, an acid-catalyzed crosslinker reacts with the hydroxyl groups in the matrix resin, crosslinking the polymer chains. This improves the crosslinking level of the photoresist composition, helping to enhance the adhesion of the photolithographic pattern and prevent it from being removed by cleaning, thereby enabling a more refined photolithographic process.

[0068] 2. The present invention adds a photobase generator to the photoresist composition to generate diethanolamine during the exposure process. The generated diethanolamine can help improve the H generated by the photoacid generator during the exposure process. + The problem of too fast migration is solved, thereby avoiding the generation of standing waves in the photolithography pattern and helping to improve the resolution of the photoresist. DETAILED DESCRIPTION

[0069] Terms and Claims of the Present Invention:

[0070] 1. The articles "a", "an" and "the" include plural referents unless expressly limited to one or more referents otherwise.

[0071] 2. Numerical ranges: Unless expressly stated otherwise, all ranges or ratios disclosed herein are to be understood to include any and all subranges or subratios contained therein. For example, a range or ratio stated as 1 to 30 is to be considered inclusive of any and all subranges or subratios, integers, decimals, or subranges or subratios comprised therein, between a minimum of 1 and a maximum of 30, including any subranges or subratios, integers, decimals, or subranges or subratios comprised therein.

[0072] The following non-limiting examples are provided to provide a more comprehensive understanding of the present invention by those skilled in the art, but are not intended to limit the present invention in any way. The following is merely illustrative of the scope of the present invention, and those skilled in the art may make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of the present invention.

[0073] The present invention will be further described below by way of specific examples. The various chemical reagents used in the examples of the present invention were obtained through conventional commercial channels unless otherwise specified. Unless otherwise specified, the contents described below are all by weight. Unless otherwise specified, it is understood that the experiments were conducted at room temperature.

[0074] In the following examples, all starting materials were either commercially available or synthesized using known procedures.

[0075] The codes and chemical structural formulas of the compounds in the following examples and comparative examples correspond to those in Table 1:

[0076] Table 1

[0077]

[0078]

[0079] In the following examples and comparative examples, the poly(4-vinylphenol) used is a commercially available product (brand: Adamas) with a weight-average molecular weight Mw of approximately 11,000.

[0080] Example 1

[0081] A photoresist having the following composition.

[0082] A mixture of 15.85 g of base resin 1, 4.65 g of poly(4-vinylphenol), 0.8 g of diphenyliodonium hexafluorophosphate, 1.5 g of compound 1, 0.5 g of compound 5, and 240 g of propylene glycol monomethyl ether acetate and diphenyl ether in a volume ratio of 1:1 was prepared by mixing all of the above ingredients to obtain a photoresist.

[0083] The preparation method of the matrix resin 1 is as follows:

[0084] 100 mmol of styrene (approximately 10.42 g), 4.4 mmol of p-phenoxystyrene (approximately 0.863 g), 7.6 mmol of p-(ethylene oxide)styrene (approximately 1.11 g), 0.37 g of azobisisoheptanenitrile (equivalent to 3% of the monomer mass), and 100 mL of ethyl acetate were mixed uniformly, heated to 60°C, and refluxed for 10 hours. Methanol was added to precipitate the mixture, filtered, washed three times with water and methanol, and dried to obtain base resin 1 (yield 10.9 g).

[0085] It is worth noting that in the various embodiments and comparative examples of the present invention, the preparation method of the matrix resin can be expanded by proportionally increasing the amount of each component within a reasonable range and / or repeating the reaction process to expand the reaction scale, thereby obtaining a sufficient amount of product matrix resin.

[0086] Example 2

[0087] Compared with Example 1, the difference is that the amount of each component in the photoresist is changed to the following:

[0088] A mixture obtained by mixing 14.1 g of base resin 1, 6.4 g of poly(4-vinylphenol), 0.6 g of diphenyliodonium hexafluorophosphate, 2.4 g of compound 1, 0.3 g of compound 5, and 280 g of propylene glycol monomethyl ether acetate and diphenyl ether in a volume ratio of 1:1.

[0089] The rest are the same.

[0090] Example 3

[0091] Compared with Example 1, the difference is that the amount of each component in the photoresist is changed to the following:

[0092] A mixture obtained by mixing 17.6 g of base resin 1, 2.9 g of poly(4-vinylphenol), 1 g of diphenyliodonium hexafluorophosphate, 0.51 g of compound 1, 0.7 g of compound 5, and 200 g of propylene glycol monomethyl ether acetate and diphenyl ether in a volume ratio of 1:1.

[0093] The rest are the same.

[0094] Example 4

[0095] Compared with Example 1, the difference is that 0.5 g of compound 5 is replaced by a mixture of 0.25 g of compound 3 and 0.25 g of compound 4, and the rest are the same.

[0096] Example 5

[0097] Compared with Example 1, the difference is that 0.5 g of compound 5 is replaced by 0.5 g of compound 2, and the rest are the same.

[0098] Example 6

[0099] Compared with Example 1, the difference is that the base resin 1 is replaced by the base resin 2 of the same weight.

[0100] The preparation method of base resin 2 is as follows:

[0101] 100 mmol of styrene (approximately 10.42 g), 6.4 mmol of p-phenoxystyrene (approximately 1.256 g), 5.6 mmol of p-(ethylene oxide)styrene (approximately 0.819 g), 0.625 g of azobisisoheptanenitrile (equivalent to 5% of the monomer mass), and 100 mL of ethyl acetate were mixed uniformly, heated to 60°C, and refluxed for 10 hours. Methanol was added to precipitate the mixture, filtered, washed three times with water and methanol, and dried to obtain base resin 2 (yield 10.5 g).

[0102] Example 7

[0103] Compared with Example 1, the difference is that the base resin 1 is replaced by the base resin 3 of the same weight.

[0104] The preparation method of base resin 3 is as follows:

[0105] 100 mmol of styrene (approximately 10.42 g), 2.4 mmol of p-phenoxystyrene (approximately 0.471 g), 9.6 mmol of p-(ethylene oxide)styrene (approximately 1.4 g), 0.245 g of azobisisoheptanenitrile (equivalent to 2% of the monomer mass), and 100 mL of ethyl acetate were mixed uniformly, heated to 60°C, and refluxed for 10 hours. Methanol was added to precipitate the mixture, filtered, washed three times with water and methanol, and dried to obtain base resin 3 (yield 10.0 g).

[0106] Comparative Example 1

[0107] Compared with Example 1, the difference is that Compound 1 is omitted, and the rest are the same.

[0108] Comparative Example 2

[0109] Compared with Example 1, the difference is that the base resin 1 is replaced by the base resin 4 of the same weight.

[0110] The synthesis method of base resin 4 is as follows

[0111] 100 mmol of styrene (approximately 10.42 g), 8.8 mmol of p-phenoxystyrene (approximately 1.72 g), 3.2 mmol of p-(ethylene oxide)styrene (approximately 0.468 g), 0.378 g of azobisisoheptanenitrile (equivalent to 3% of the monomer mass), and 100 mL of ethyl acetate were mixed uniformly, heated to 60°C, and refluxed for 10 hours. Methanol was added to precipitate, filtered, washed three times with water and methanol, and dried to obtain base resin 1 (yield 10.0 g).

[0112] Comparative Example 3

[0113] Compared with Example 1, the difference is that the base resin 1 is replaced by the base resin 5 of the same weight.

[0114] The synthesis method of base resin 5 is as follows

[0115] 100 mmol of styrene (about 10.42 g), 7.7 mmol of p-phenoxystyrene (about 1.51 g), 13.3 mmol of p-(ethylene oxide)styrene (about 1.94 g), 0.416 g of azobisisoheptanenitrile (equivalent to 3% of the monomer mass) and 100 mL of ethyl acetate were mixed evenly, heated to 60°C, and refluxed for 10 hours. Methanol was added to precipitate, filtered, washed three times with water and methanol respectively, and dried to obtain base resin 1 (yield 10.6 g). Comparative Example 4

[0116] Compared with Example 1, the difference is that poly(4-vinylphenol) is omitted, the weight of the base resin 1 is changed to 20.5 g, and the rest are the same.

[0117] Comparative Example 5

[0118] Compared with Example 1, the difference is that the base resin 1 is omitted, the amount of poly (4-vinylphenol) used is changed to 20.5g, and the rest are the same.

[0119] Comparative Example 6

[0120] Compared with Example 1, the difference is that the base resin 1 is replaced with polystyrene of equal weight, and the other photoresist compositions are the same.

[0121] The synthesis method of polystyrene is as follows:

[0122] Mix 100 mmol of styrene (approximately 10.42 g), 0.31 g of azobisisoheptanenitrile (equivalent to 3% of the monomer mass), and 100 mL of ethyl acetate. Heat to 60°C and reflux for 10 hours. Add methanol to precipitate, filter, wash three times with water and methanol, and dry to obtain polystyrene (yield 9.1 g).

[0123] Application Examples

[0124] The photoresist composition was evenly spin-coated on the surface of the copper-plated silicon wafer, with the film thickness controlled at 0.3 μm and 1.0 μm respectively; heated on a hot plate at 100°C for 60 seconds, exposed using a KrF exposure machine, and then developed with a 1.1% aqueous solution of tetrabutylammonium hydroxide, and heated on a hot plate at 110°C for 90 seconds to harden the film.

[0125] Effect evaluation

[0126] 1. Structural characterization of matrix resin

[0127] The structures of base resin 1 prepared in Example 1, base resin 2 prepared in Example 6, base resin 3 prepared in Example 7, base resin 4 prepared in Comparative Example 2, and base resin 5 prepared in Comparative Example 3 were characterized respectively.

[0128] 1.1 Number average molecular weight, weight average molecular weight and polymer dispersity index (PDI) of the matrix resin

[0129] With reference to the prior art "Study on the Determination of Molecular Weight and Molecular Weight Distribution of Polystyrene Using a Rheometer" (Analysis and Testing Technology and Instruments, September 2007, Vol. 13, No. 3), the number average molecular weight Mn, weight average molecular weight Mw and polymer dispersity index PDI of matrix resins 1 to 5 were characterized.

[0130] PDI=Mw÷Mn.

[0131] The test results are shown in Table 2:

[0132] Table 2

[0133] Group Base resin 1 Base resin 2 Base resin 3 Base resin 4 Base resin 5 Mw 23497 23214 23097 23583 25427 Mn 11864 10929 11056 10219 11913 PDI 1.98 2.12 2.09 2.31 2.13

[0134] 1.2. Epoxy value of base resin

[0135] The epoxy value of the matrix resin is tested by the improved hydrochloric acid acetone method. The specific method is as follows:

[0136] Mix concentrated hydrochloric acid and acetone in a volume ratio of 1:40 to prepare a hydrochloric acid-acetone solution. Add 20 mL of the hydrochloric acid-acetone solution to 0.5 g of each base resin and allow to react on a shaker for 0.5 h. Hydrogen chloride reacts with epoxy groups in a ring-opening addition reaction, creating one epoxy group for each chlorine atom added to the polymer. In a fume hood, evaporate the hydrochloric acid and acetone to dryness. Add two small amounts of chromatographic-grade anhydrous ethanol to each, wash, and evaporate to dryness to obtain the chlorinated base resin. X-ray fluorescence spectrometry (XRF) can be used to determine the chlorine content (mmol / g) in the chlorinated base resin. The epoxy value of the base resin can be calculated using the following formula.

[0137] Epoxy value = ACl ÷(1-A Cl ×M HCl ).

[0138] Among them, A Cl is the chlorine content in the matrix resin after chlorine addition (mmol / g), M HCl is the molecular weight of hydrogen chloride, in g / mol. (For ease of calculation, it can be converted to g / mmol, 1g / mol = 10 -3 g / mmol. )

[0139] 1.3. Oxygen content of matrix resin

[0140] The combustion method can be used to determine the oxygen content of each matrix resin. This oxygen content represents the total content of phenoxy and epoxy groups in the polymer. Combined with the epoxy value of the matrix resin, the range of values ​​for each structural unit in the polymer can be roughly determined.

[0141] The epoxy value and oxygen weight content (oxygen content) of the matrix resin are shown in Table 3:

[0142] Table 3

[0143] Group Base resin 1 Base resin 2 Base resin 3 Base resin 4 Base resin 5 Epoxide value (mmol / g) 0.608 0.347 0.702 0.173 0.895 Oxygen content (%) 1.361 1.355 1.364 1.336 2.180

[0144] 2. Adhesion test

[0145] 2.1. Hundred-grid test

[0146] Use a grid knife to create a grid of 100 1mm x 1mm squares on the surface of the test sample. Each grid line should be deep enough to meet the bottom layer where the photoresist meets the copper-plated silicon wafer. Use 3M 600 tape to firmly adhere the small grid to be tested, then quickly remove the tape. Repeat the test twice at the same location. Count the peeling and determine the adhesion rating. The rating criteria are as follows:

[0147] Grade 5B: The edges of the cut are completely smooth, and there is no peeling on the lattice edges.

[0148] Grade 4B: There is small flake peeling at the intersection of the cuts, and the actual damage in the cross-cut area is ≤5%.

[0149] Grade 3B: The edges and / or intersections of the cut are peeled, with an area greater than 5%-15%.

[0150] Grade 2B: There is partial peeling or large-scale peeling along the edge of the cut, and the peeling area exceeds 15%-35%.

[0151] Grade 1B: Large pieces of the cut edge are peeling off, or some squares are partially or completely peeling off, with an area greater than 35%-65%.

[0152] Grade 0B: Flakes of film fall off at the edges and intersections of the scribe lines, and the total area of ​​the film falls off is greater than 65%.

[0153] The test results of adhesion of each group are shown in Table 4:

[0154] Table 4

[0155]

[0156]

[0157] 2.2. Undercut phenomenon test.

[0158] Undercutting refers to the inward depression of the edge of the photoresist film at the junction with the substrate. Causes of undercutting include shrinkage of the photoresist film itself and / or inward depression of the edge due to residual etchant. Photoresist films with undercutting exhibit reduced adhesion to the substrate. Evaluating the incidence of undercutting can be used to assess photoresist adhesion.

[0159] The substrates provided in Examples 1-7 and Comparative Examples 1-6 were longitudinally sectioned, with five samples from each group used as parallel experiments. The longitudinal sections were then observed using a scanning electron microscope to check for undercuts. The results are shown in Table 5.

[0160] Table 5

[0161]

[0162]

[0163] It can be seen that compared with the comparative examples, the photoresists provided in Examples 1 to 7 have stronger adhesion to the substrate.

[0164] 3. Resolution evaluation after photolithography

[0165] Graphic inspection was performed using a critical dimension scanning electron microscope (CD-SEM). The optimal exposure energy was defined as the exposure energy (mJ / cm2) when the exposure line width was the target resolution at a specified resolution. 2 The maximum resolution of a photoresist is defined as the minimum feature size that can be formed on a silicon wafer at the optimal exposure energy. The line edge roughness (LER) of a 160nm L / S pattern was evaluated by CD-SEM.

[0166] The experimental results of the 0.3 μm thick film are shown in Table 6:

[0167] Table 6

[0168] Group Maximum resolution (nm) Line edge roughness (nm) Example 1 161.2 6.6 Example 2 159.6 6.7 Example 3 160.9 6.9 Example 4 159.3 6.2 Example 5 159.7 5.9 Example 6 160.1 6.0 Example 7 160.3 6.4 Comparative Example 1 334.1 7.0 Comparative Example 2 379.0 6.9 Comparative Example 3 383.8 6.9 Comparative Example 4 494.4 7.8 Comparative Example 5 480.8 7.9 Comparative Example 6 449.7 9.7

[0169] The experimental results of 1 μm thick film are shown in Table 7:

[0170] Table 7

[0171]

[0172]

[0173] It can be seen that, compared with the comparative examples, the embodiments can achieve a finer photolithography effect after the photoresist is exposed to light.

[0174] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A matrix resin, characterized in that The structural units of the base resin are composed of the following groups: The weight average molecular weight of the matrix resin is in the range of 2000-50000; the weight content of oxygen element in the matrix resin is 1%-1.5%; and the epoxy value of the matrix resin is 0.2-0.8 mmol / g.

2. The method for preparing the matrix resin according to claim 1, characterized in that: The following steps are involved: Styrene, p-phenoxystyrene, p-(epoxyethyl)styrene, a solvent and an initiator are mixed and heated for reaction to obtain a base resin.

3. The preparation method according to claim 2, characterized in that The molar ratio of styrene, p-phenoxystyrene, and p-(ethylene oxide)styrene is 100:2.4-6.4:5.6-9.6, and the weight of the initiator is 0.5%-10% of the sum of the weights of styrene, p-phenoxystyrene, and p-(ethylene oxide)styrene; the solvent is selected from at least one of toluene, xylene, diphenyl ether, dimethyl sulfoxide, ethyl acetate, and ethyl lactate; the temperature of the heating reaction is 50-90°C, and the time of the heating reaction is 6-30 hours.

4. A photoresist composition, characterized in that The composition comprises, by weight, 141-176 parts of a base resin, 29-64 parts of poly(4-vinylphenol), 6-10 parts of an acid generator, and 2000-2800 parts of an organic solvent; Wherein, the base resin is the base resin described in claim 1 or the base resin prepared by the preparation method described in any one of claims 2-3.

5. The photoresist composition according to claim 4, characterized in that The photobase generator further comprises 3-7 parts by weight, wherein the photobase generator is selected from at least one of the following components: The solvent is selected from at least one of alcohols, esters, ethers, aromatic hydrocarbons and ketones.

6. The photoresist composition according to claim 4 or 5, characterized in that The invention also comprises 5.1-24 parts by weight of a cross-linking agent, wherein the cross-linking agent is selected from at least one of an etherified amino cross-linking agent and an etherified polyphenyl cross-linking agent.

7. A photoresist, characterized in that Made from the photoresist composition according to any one of claims 4 to 6.

8. Use of the photoresist according to claim 7 in forming a photoresist pattern, characterized in that: It includes film making process, exposure process and development process.

9. The use according to claim 8, characterized in that The following steps are involved: S1, coating a photoresist composition on a substrate to obtain a coated backplane; S2, coating the coated board obtained in step S1 with glue and then baking it at a temperature of 90-130° C. for 60-120 seconds to obtain a PEB board; S3, exposure: the PEB board obtained in step S2 is exposed using a KrF exposure machine to obtain an exposed board; S4, performing post-exposure baking on the exposed board obtained in step S3 at a temperature of 110-140° C. for 60-120 seconds to obtain a PAB board; S5, development: the PAB board obtained in step S4 is developed using a developer to obtain a circuit substrate product.

10. Use of the base resin according to claim 1, or the base resin prepared by the preparation method according to any one of claims 2 to 3, or the photoresist composition according to any one of claims 4 to 6, or the photoresist according to claim 7 in the preparation of circuit substrates and integrated circuit boards.

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