WO2018205896A1 - Poly(p-hydroxystyrene)-based oxetane resin, and synthesis and use thereof - Google Patents

Abstract

Disclosed are a polymer of formula (I), a method for preparing the polymer of formula (I), the use of the polymer of formula (I) as a film-forming resin in a photoresist, and a photoresist comprising the polymer of formula (I) as a film-forming resin.

Description

Poly-p-hydroxystyrene oxetane resin, its synthesis and application Technical field

This invention relates to poly(p-hydroxystyrene) oxetane resins. This resin can be used as a film-forming resin for a photoresist system. The invention also relates to the preparation of poly(p-hydroxystyrene) oxetane resins and their use as film-forming resins in photoresist systems.

Background technique

The photoresist is an etch-resistant film material whose solubility changes under irradiation or irradiation of a light source such as an ultraviolet light, an excimer laser, an electron beam, an ion beam, or an X-ray. Since its invention in the 1950s, photoresist has become the core process material in the semiconductor industry and is widely used in the manufacture of integrated circuits and printed circuit boards. In the early 1990s, photoresist was applied to the processing of LCD devices, which played an important role in promoting the large size, high definition and colorization of LCD panels. Photoresist also plays a pivotal role in the fine processing of microelectronics manufacturing from micron, submicron, deep submicron to nanoscale.

According to the change of solubility of the photoresist before and after exposure, it can be divided into a positive photoresist and a negative photoresist. The solubility of the positive photoresist increases after exposure and development, and the solubility of the negative photoresist decreases after exposure and development. In general, positive photoresists have the advantages of high resolution, strong resistance to dry etching, good heat resistance, easy gel removal, good contrast, etc., but poor adhesion and mechanical strength, and high cost. . The negative photoresist has good adhesion to the substrate, acid and alkali resistance, and fast speed. However, due to cross-linking in the exposed area, the solubility is weakened, which causes deformation and swelling during development, thereby limiting its Resolution.

As electronic devices continue to evolve toward high integration and refinement, the requirements for performance such as photoresist resolution are also increasing. Lithography has gone from g-line (436 nm) lithography, i-line (365 nm) lithography, to KrF (deep ultraviolet 248 nm) lithography, ArF (deep ultraviolet 193 nm) lithography, and next-generation extreme ultraviolet (EUV, 13.5). Nm) The development of lithography, corresponding to the photoresist of each exposure wavelength also came into being. The key formulation components in the photoresist, such as film-forming resins, photoinitiators, and additives, also change, making the overall performance of the photoresist better meet the process requirements.

Micro-Electro-Mechanical System (MEMS) is a miniaturized mechatronics intelligent system consisting of three main components: micro-sensor, micro-actuator and micro-energy. The system size is generally micron or even smaller, and the internal structure size is even micron. nanoscale. Micro-electromechanical systems have the advantages of miniaturization, intelligence, integration, multi-function and suitable for mass production. They have broad development prospects in the fields of military, aerospace, information and communication, biomedicine, automatic control, and automobile industry.

The microstructure fabrication of MEMS devices is achieved by a photolithography process. Unlike the pursuit of higher resolution in lithography processes in general integrated circuit fabrication, MEMS fabrication pursues higher aspect ratios, which require photoresists for MEMS to have a certain thickness. In order to meet the needs of the development of MEMS products, thick film photoresist came into being. In general, thick film photoresists require good photosensitivity and aspect ratio, and coating thicknesses typically range to at least 10 microns. In MEMS manufacturing, thick glue can be directly used as a working part of MEMS devices, or as a sacrificial layer material to fabricate MEMS devices with film structures and cantilever structures, or as a mask layer for wet etching, or as an electroplated Model for making 3D MEMS devices with non-silicon materials. Therefore, with the continuous development of MEMS, it is very important to develop thick film photoresist suitable for MEMS manufacturing.

At present, the commercially available thick film lithography positive adhesives mainly include AZ series positive glue, SJR3000 series positive glue, Ma-p100 positive glue and SPR 220-7 positive glue, etc. The negative glue is negative by SU-8 series produced by American MicroChem Company. Glue-based.

Commercially available positive thick film photoresists are mostly diazonaphthoquinone positive photoresists, mainly composed of phenolic resin, photosensitive compound diazonaphthoquinone and organic solvent. Under ultraviolet light irradiation, the diazonaphthoquinone compound in the exposed area undergoes photolysis reaction, loses a molecule of nitrogen, and the Wolff rearrangement is converted into hydrazine carboxylic acid, so that the film can be dissolved in the alkaline developing solution. In the non-exposed area, photochemical reaction does not occur, and the hydroxyl group of the phenolic resin and the diazonaphthoquinone compound act to form a stable six-membered ring structure by hydrogen bonding, thereby inhibiting dissolution of the resin.

SU-8 series photoresist is an epoxy resin photoresist. Due to its good chemical, optical and mechanical properties, it has become the most widely used and widely used lithographic thick adhesive in MEMS. The main components of the SU-8 photoresist include a bisphenol A type novolac epoxy resin, an organic solvent (γ-butyrolactone or cyclopentanone), and a small amount of a photoacid generator triarylsulfonium salt. When exposed, the triarylsulfonium salt absorbs photons and releases a strong acid. During the post-baking process, the epoxy group in the acid-catalyzed epoxy resin undergoes cationic polymerization cross-linking, and the cross-linking reaction grows in chains, which can be formed quickly. A dense molecular network structure of large molecular weight which is insoluble in the developing solution during development and thus retained. In the non-exposed area, the photoacid generator cannot produce acid, and thus cannot catalyze the polymerization and crosslinking of the epoxy group, and the resin is soluble in the developer during development.

The sensitization principle of the SU-8 series photoresist is based on cationic photocuring of epoxy resin. Cationic photocuring system is rapidly developing as an important system in UV curing technology. Compared with free radical photocuring system, its most significant advantage is that it is not inhibited by oxygen, the volume shrinkage rate is small, the curing reaction is not easy to terminate, and the light stops. After that, the curing reaction can continue and the toxicity is low. Due to these advantages, cationic photocurable materials are very suitable for use as a major component of thick film photoresists.

At present, cationic photocuring systems mainly include vinyl ether systems, epoxy systems, and oxetane systems.

The main advantage of the vinyl ether cationic photocuring system is that the curing rate is very fast, there is no induction period, it can be cured at normal temperature, but there are disadvantages such as poor stability, and the viscosity is low, and it is difficult to form a thick film.

Epoxy system is the most commonly used cationic photocuring system. It has a wide variety of monomers, low price, good adhesion after curing, high strength and high viscosity. Although curing is affected by environmental temperature and humidity, the curing reaction rate is slow. However, it can be reduced by appropriate process conditions, and is more suitable for thick film photoresist film-forming resins. As an epoxy system, mainly including novolac epoxy resin, its main performance characteristics are as described for the film-forming resin of SU-8 photoresist described above, which has the disadvantage that the phenolic resin is synthesized by polycondensation reaction. The degree of polycondensation reaction is not easy to control, and the obtained product has a wide molecular weight distribution, and the product needs to be classified and screened, the process flow is complicated, the operation is difficult, and the cost is high. If the molecular weight of the resin is not uniform, the dissolution in the developer is not uniform, which may affect the resolution of the photoresist.

The oxetane photocuring system is a relatively new type of cationic photocuring system, and currently has a small number of monomers and is relatively expensive. Compared with the epoxy system, the significant advantage is that the curing is less affected by the ambient temperature, it can be cured at normal temperature, and the curing is thorough. When used for photoresist film-forming resin, this advantage is beneficial to the resin in the exposed area. The light cures the reaction to achieve higher resolution.

In addition to phenolic resins, another type of film-forming resin for photoresists is poly-p-hydroxystyrene and its derivatives. The most widely used poly-p-hydroxystyrene whose hydroxyl group is protected in whole or in part is often used as a protecting group. The group has a butyl carbonate, an acetal, a ketal, a silane group and the like. Compared with phenolic resin, the remarkable advantage of poly(p-hydroxystyrene) is that it is synthesized by polyaddition reaction, so that a resin having a high molecular weight and a narrow molecular weight distribution can be obtained by a cationically controlled living polymerization method, and polyparaxyl styrene is very Good UV light transmission, high molecular weight, narrow molecular weight distribution, good UV light transmission and other characteristics are conducive to improve the resolution of the photoresist. This type of photoresist is a positive photoresist. The imaging principle is: in the exposed area, the acid generated by the acid generator catalyzes the decomposition of the film-forming resin, removes the protective group, and dissolves in the alkaline developer instead of the exposed area. The resin is insoluble in the alkaline developer due to the presence of the protecting group. The imaging principle of the poly-p-hydroxystyrene-based lithographic negative adhesive is: in the exposed region, the acid-catalyzed crosslinking agent reacts with the film-forming resin to cause the exposed resin to be insoluble in the developer, and the non-exposed area is dissolved in the developer. . However, there are few types of poly(p-hydroxystyrene) lithographic negative adhesives which are currently developed, and the obtained photoresist is not a thick film photoresist, and is a common photoresist.

Summary of the invention

In view of the problems in the prior art, the inventors of the present invention conducted extensive and intensive research on the film-forming resin of photoresist, in order to find a new film-forming resin for cationic photocurable photoresist. The film-forming resin has the advantages of good ultraviolet light transmittance, large viscosity, thick film formation, complete photocuring, and high resolution. The present inventors have found that the introduction of an oxetane moiety on a polyparaxylene molecule can achieve the aforementioned object. Among them, polypara-hydroxystyrene is used as the main structure, and polyparaxyl styrene itself is synthesized by polyaddition reaction, and a resin having a high molecular weight and a narrow molecular weight distribution can be obtained by a cation-controlled living polymerization method, and a poly-p-hydroxy group is obtained. Styrene has good UV light transmission, and high molecular weight, narrow molecular weight distribution, good UV light transmission and other characteristics are beneficial to improve the resolution of the photoresist; a large amount of benzene ring, benzene exists in the resin structure The rigidity of the ring makes the resin have good etching resistance; the oxetane group is introduced into the resin, and the oxetane group can undergo cationic photopolymerization, complete photocuring, no oxygen inhibition, and thus polymerization. It is not easy to terminate, and polymerization can be continued in the dark, and a crosslinked network is easily formed in the exposed area, thereby obtaining a high-resolution lithographic pattern; another advantage of the oxetane resin is that the viscosity is large, so the obtained film is on the substrate. The adhesion is good, and a thick photoresist film can be obtained. Due to these advantages, the modified resin has a good application prospect in the field of thick film photoresist. The present invention has been achieved based on the foregoing findings.

Accordingly, it is an object of the present invention to provide a modified polypara-hydroxystyrene resin containing an oxetane moiety. When used as a film-forming resin for a photoresist, the resin has the advantages of good ultraviolet light transmittance, large viscosity, thick film formation, complete photocuring, and high resolution.

Another object of the present invention is to provide a process for preparing a modified polyparaxyl styrene resin containing an oxetane moiety of the present invention.

Still another object of the present invention is to provide a use of the modified polyparaxyl styrene resin containing an oxetane moiety of the present invention as a film-forming resin in a photoresist.

Still another object of the present invention is to provide a photoresist comprising the modified polyparaxyl styrene resin containing the oxetane moiety of the present invention.

The technical solution for achieving the above object of the present invention can be summarized as follows:

1. A polymer of the following formula (I):

among them:

R _a -R _d are each independently selected from H, halogen, C ₁ -C ₆ alkyl, halogenated C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, halogenated C ₁ -C ₆ alkane a group of an oxy group, a C ₃ -C ₁₂ cycloalkyl group and a halogenated C ₃ -C ₁₂ cycloalkyl group;

R is selected from H, halo, C ₁ -C ₆ alkyl, halo C ₁ -C ₆ alkyl, C ₁ -C ₆ hydroxyalkyl, C ₁ -C ₆ alkoxy and halogeno C ₁ -C _a group of ₆ alkoxy groups;

n is a number of 20-40.

2. The polymer according to item 1, wherein

R _a -R _d are each independently selected from the group consisting of H, chlorine, bromine, C ₁ -C ₄ alkyl, chloro C ₁ -C ₄ alkyl, bromo C ₁ -C ₄ alkyl, C ₁ -C ₄ a group of alkoxy, chloro C ₁ -C ₄ alkoxy, bromo C ₁ -C ₄ alkoxy and C ₃ -C ₆ cycloalkyl, preferably R _a -R _d are each independently selected from a group of H, C ₁ -C ₄ alkyl, halo C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, cyclopropyl, cyclobutyl and cyclopentyl; and/or

R is selected from the group consisting of H, chlorine, bromine, C ₁ -C ₄ alkyl, chloro C ₁ -C ₄ alkyl, bromo C ₁ -C ₄ alkyl, C ₁ -C ₄ hydroxyalkyl, C ₁ - a group of a C ₄ alkoxy group, a chloro C ₁ -C ₄ alkoxy group, a brominated C ₁ -C ₄ alkoxy group and a C ₃ -C ₆ cycloalkyl group, preferably R is H, chlorine, C ₁ - C ₄ alkyl, chloro C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, cyclopropyl, cyclobutyl or cyclopentyl; and/or

n is a number from 24 to 36, preferably a number from 25 to 30.

3. A process for the preparation of a polymer of formula (I) according to item 1 or 2, wherein, when X is a halogen, the polymer of formula (II) is reacted with a compound of formula (III); when X is a hydroxyl group The compound of formula (III) is first reacted with p-toluenesulfonyl chloride to give a compound of formula (IV), which is then reacted with a polymer of formula (II).

Wherein R _a -R _d , R and n are each as defined in the first or second term, and X is a halogen, preferably chlorine or bromine, or X is a hydroxyl group.

4. The method according to item 3, wherein, when X is a halogen, the reaction of the polymer of the formula (II) with the compound of the formula (III) is carried out in the presence of a basic catalyst, preferably the basic catalyst is selected from the group consisting of NaOH and KOH. One or more of Na ₂ CO ₃ and K ₂ CO ₃ , preferably K ₂ CO ₃ and/or KOH; when X is a hydroxyl group, the reaction of the polymer of formula (II) with the compound of formula (IV) is The basic catalyst is preferably present in the presence of a basic catalyst, preferably one or more selected from the group consisting of NaOH, KOH, Na ₂ CO ₃ and K ₂ CO ₃ , preferably K ₂ CO ₃ and/or KOH.

5. The method according to item 3 or 4, wherein, when X is a halogen, the polymer of the formula (II) and the compound of the formula (III) are used in an amount such that the monomer unit contained in the polymer of the formula (II) and the formula (III) The molar ratio of the compound is from 1:1 to 1:3, preferably from 1:1.8 to 1:2; when X is a hydroxyl group, the amount of the polymer of formula (II) and the compound of formula (IV) is such that formula (II) The molar ratio of the monomer units contained in the polymer to the compound of the formula (IV) is from 1:1 to 1:2, preferably from 1:1.5 to 1:2.

The method according to any one of items 3-5, wherein, when X is a halogen, the polymer of the formula (II) and the basic catalyst are used in an amount such that the monomer unit and the base contained in the polymer of the formula (II) The molar ratio of the catalyst is from 1:0.1 to 1:1:1, preferably from 1:0.6 to 1:1; when X is a hydroxyl group, the polymer of the formula (II) and the basic catalyst are used in an amount such that the polymer of the formula (II) The molar ratio of the monomer unit to the basic catalyst is from 1:0.1 to 1:1, preferably from 1:0.5 to 1:1.

The process according to any one of the items 3-6, wherein, when X is a halogen, the reaction of the polymer of the formula (II) with the compound of the formula (III) is carried out at 50-80 ° C, preferably at 50-70 The reaction is carried out at ° C; when X is a hydroxyl group, the reaction of the compound of the formula (III) with p-toluenesulfonyl chloride is carried out at -10 to 10 ° C, preferably at -5 to 5 ° C, and/or the polymerization of the formula (II) The reaction of the compound with the compound of the formula (IV) is carried out at 60 to 80 ° C, preferably at 60 to 70 ° C.

The process according to any one of items 3 to 7, wherein, when X is a hydroxyl group, the reaction of the polymer of the formula (II) with the compound of the formula (IV) is carried out in the presence of a phase transfer catalyst, preferably a phase transfer catalyst A tetraalkylammonium halide such as a tetra C ₁ -C ₄ alkylammonium halide such as tetrabutylammonium bromide.

9. Use of a polymer of formula (I) according to item 1 or 2 as a film-forming resin in a photoresist.

10. A photoresist comprising the polymer of formula (I) according to item 1 or 2 as a film-forming resin.

11. The photoresist according to item 10, which comprises the polymer of the formula (I) according to the item 1 or 2 as a film-forming resin, a photoacid generator, a photopolymerizable monomer, a basic additive, a sensitizer And a photoresist solvent; preferably, the mass ratio of the film-forming resin, photoacid generator, photopolymerizable monomer, basic additive, sensitizer, and photoresist solvent is (30-40): (1 4): (20-25): (1-2): (0-2): (40-50); more preferably the film-forming resin, photoacid generator, photopolymerizable monomer, alkaline additive, The mass ratio of the sensitizer to the photoresist solvent was 35:3.0:25:1.5:1.5:50.

12. The photoresist according to Item 11, wherein the photoacid generator is any one or more of an iodonium salt, a sulfonium salt, and a heterocyclic acid generator; preferably the iodonium salt is produced. The acid agent, the sulfonium salt acid generator and the heterocyclic acid generator have the following general formulae (V), (VI) and (VII):

Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently phenyl, halophenyl, nitrophenyl, C ₆ -C ₁₀ aryl or C _{a 1-} C ₁₀ alkyl substituted benzoyl;

Y, Z are non-nucleophilic anions such as triflate, BF ₄ ^- , ClO ₄ ^- , PF ₆ ^- , AsF ₆ ^- or SbF ₆ ^- .

13. The photoresist according to item 11 or 12, wherein

The photopolymerizable monomer is N-vinylpyrrolidone, hydroxyethyl methacrylate or a mixture thereof; and/or

The basic additive is a tertiary amine and/or a quaternary amine, more preferably any one or more of triethanolamine, trioctylamine and tributylamine; and/or

The sensitizer is any one or more of 2,4-diethylthiaxanthone, 9-fluorenyl methanol and 1-[(2,4-dimethylphenyl)azo]-2-naphthol Kind; and/or

The photoresist solvent is any one or more of cyclopentanone, γ-butyrolactone, and ethyl acetate.

These and other objects, features and advantages of the present invention will become apparent to those skilled in

DRAWINGS

1 is a lithographic image of four photoresists obtained in Example 9;

2 is a lithographic image of four photoresists obtained in Example 10.

detailed description

According to an aspect of the invention, there is provided a polymer of the following formula (I):

among them:

R _a -R _d are each independently selected from H, halogen, C ₁ -C ₆ alkyl, halogenated C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, halogenated C ₁ -C ₆ alkane a group of an oxy group, a C ₃ -C ₁₂ cycloalkyl group and a halogenated C ₃ -C ₁₂ cycloalkyl group;

R is selected from the group consisting of H, halogen, C ₁ -C ₆ alkyl, halogenated C ₁ -C ₆ alkyl, C ₁ -C ₆ hydroxyalkyl, C ₁ -C ₆ alkoxy, and halogenated C ₁ -C _a group of ₆ alkoxy groups;

n is a number of 20-40.

In the present invention, R _{a -} R _d is a group on the benzene ring. R _a -R _d are the same or different from each other, and are each independently selected from the group consisting of H, halogen, C ₁ -C ₆ alkyl, halogenated C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, halogenated a group of a C ₁ -C ₆ alkoxy group, a C ₃ -C ₁₂ cycloalkyl group, and a halogenated C ₃ -C ₁₂ cycloalkyl group. Preferably, R _a -R _d are each independently selected from the group consisting of H, chlorine, bromine, C ₁ -C ₄ alkyl, chloro C ₁ -C ₄ alkyl, bromo C ₁ -C ₄ alkyl, C _a group of ₁ -C ₄ alkoxy, chloro C ₁ -C ₄ alkoxy, bromo C ₁ -C ₄ alkoxy and C ₃ -C ₆ cycloalkyl. It is particularly preferred that R _a -R _d are each independently selected from the group consisting of H, C ₁ -C ₄ alkyl, halogenated C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, cyclopropyl, ring a group of a butyl group and a cyclopentyl group.

In the present invention, R is a group on the oxetane ring. R is selected from the group consisting of H, halogen, C ₁ -C ₆ alkyl, halogenated C ₁ -C ₆ alkyl, C ₁ -C ₆ hydroxyalkyl, C ₁ -C ₆ alkoxy, and halogenated C ₁ -C _a group of ₆ alkoxy groups. Preferably, R is selected from the group consisting of H, chlorine, bromine, C ₁ -C ₄ alkyl, chloro C ₁ -C ₄ alkyl, bromo C ₁ -C ₄ alkyl, C ₁ -C ₄ hydroxyalkyl a group of a C ₁ -C ₄ alkoxy group, a chloro C ₁ -C ₄ alkoxy group, a brominated C ₁ -C ₄ alkoxy group, and a C ₃ -C ₆ cycloalkyl group. It is particularly preferred that R is H, chlorine, C ₁ -C ₄ alkyl, chloro C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, cyclopropyl, cyclobutyl or cyclopentyl.

In the present invention, n represents the number of structural units of the polypara-hydroxystyrene epoxy resin, and is usually a number of from 20 to 40, preferably from 24 to 36, more preferably from 25 to 30.

According to another aspect of the present invention, there is also provided a process for the preparation of a polymer of the formula (I) according to the invention, wherein, when X is a halogen, the polymer of the formula (II) is reacted with a compound of the formula (III); When X is a hydroxyl group, the compound of the formula (III) is first reacted with p-toluenesulfonyl chloride to give a compound of the formula (IV), and the compound of the formula (IV) is further reacted with the polymer of the formula (II).

Wherein R _a -R _d , R and n are each as defined for the polymer of formula (I), and X is a halogen, preferably chlorine or bromine, or X is a hydroxyl group.

In the present invention, when X is a halogen, the reaction of the polymer of the formula (II) with the compound of the formula (III) is usually carried out in the presence of a basic catalyst. There is no particular limitation on the selection of the basic catalyst. Preferably, the basic catalyst is one or more of NaOH, KOH, Na ₂ CO ₃ , K ₂ CO ₃ . It is particularly preferred that the basic catalyst is K ₂ CO ₃ and/or KOH. In the present invention, when X is a halogen, the reaction of the polymer of the formula (II) with the compound of the formula (III) is not particularly limited with respect to the amount of the basic catalyst. Preferably, the polymer of formula (II) and the basic catalyst are used in an amount such that the molar ratio of monomer units to basic catalyst contained in the polymer of formula (II) is from 1:0.1 to 1:1. It is particularly preferred that the polymer of formula (II) and the basic catalyst are used in an amount such that the molar ratio of monomer units to basic catalyst contained in the polymer of formula (II) is from 1:0.6 to 1:1.

In the present invention, when X is a halogen, the reaction of the polymer of the formula (II) with the compound of the formula (III) generally ensures that the polymer of the formula (II) is sufficiently reacted. Accordingly, the polymer of formula (II) and the compound of formula (III) are used in an amount such that the molar ratio of monomer units contained in the polymer of formula (II) to the compound of formula (III) is generally from 1:1 to 1:3. Preferably, the polymer of formula (II) and the compound of formula (III) are used in an amount such that the molar ratio of monomer units of formula (II) to compound of formula (III) is from 1:1.8 to 1:2.

In the present invention, when X is a halogen, the reaction of the polymer of the formula (II) with the compound of the formula (III) is usually carried out in a solution. There is no particular limitation on the choice of the solvent as long as the respective reactants can be dissolved. Advantageously, the reaction of the polymer of formula (II) with a compound of formula (III) is carried out in the presence of an organic solvent. Preferably, the organic solvent is one or more selected from the group consisting of ethanol, acetone, ethyl acetate, dichloromethane, and chloroform. It is particularly preferred that the organic solvent is one selected from the group consisting of ethanol and acetone.

In the present invention, when X is a halogen, the reaction of the polymer of the formula (II) with the compound of the formula (III) is required for the reaction conditions such as temperature and pressure. Preferably, the reaction is carried out at 50-80 °C. It is particularly preferred that the reaction be carried out at 50-70 °C. The reaction time is advantageously from 12 to 15 hours. The reaction pressure is advantageously atmospheric.

In the present invention, when X is a hydroxyl group, in order to prepare a polymer of the formula (I), the compound of the formula (III) is first reacted with p-toluenesulfonyl chloride to obtain a compound of the following formula (IV), wherein R is a polymer of the formula (I) As defined, the compound of formula (IV) is then reacted with a polymer of formula (II).

For the preparation of the compound of the formula (IV), the reaction of the compound of the formula (III) with p-toluenesulfonyl chloride is usually carried out in a solution. There is no particular limitation on the choice of the solvent as long as the respective reactants can be dissolved. Advantageously, the reaction of the compound of formula (III) with p-toluenesulfonyl chloride is carried out in the presence of an organic solvent. Preferably, the organic solvent is one or more selected from the group consisting of pyridine, dichloromethane, and chloroform. It is particularly preferred that the organic solvent is one selected from the group consisting of pyridine and dichloromethane. The molar ratio of the compound of the formula (III) to p-toluenesulfonyl chloride is usually from 1:1 to 1:1.5, preferably from 1:1.2 to 1:1.5. The reaction of the compound of the formula (III) with p-toluenesulfonyl chloride is conventional for the reaction conditions such as temperature and pressure. Preferably, the reaction is carried out at -10 to 10 °C. It is particularly preferred that the reaction be carried out at -5 to 5 °C. The reaction time is advantageously 2-3 hours. The reaction pressure is advantageously atmospheric.

In the present invention, when X is a hydroxyl group, the reaction of the polymer of the formula (II) with the compound of the formula (IV) is usually carried out in the presence of a basic catalyst. There is no particular limitation on the selection of the basic catalyst. Preferably, the basic catalyst is one or more of NaOH, KOH, Na ₂ CO ₃ , K ₂ CO ₃ . It is particularly preferred that the basic catalyst is K ₂ CO ₃ and/or KOH. In the present invention, when X is a hydroxyl group, the reaction of the polymer of the formula (II) with the compound of the formula (IV) is not particularly limited with respect to the amount of the basic catalyst. Preferably, the polymer of formula (II) and the basic catalyst are used in an amount such that the molar ratio of monomer units to basic catalyst contained in the polymer of formula (II) is from 1:0.1 to 1:1. It is particularly preferred that the polymer of formula (II) and the basic catalyst are used in an amount such that the molar ratio of monomer units to basic catalyst contained in the polymer of formula (II) is from 1:0.5 to 1:1.

In the present invention, when X is a hydroxyl group, the reaction of the polymer of the formula (II) with the compound of the formula (IV) is usually carried out in the presence of a phase transfer catalyst. There is no particular limitation on the choice of the phase transfer catalyst. Preferably, the phase transfer catalyst is a tetraalkylammonium halide such as a tetra C ₁ -C ₄ alkyl ammonium halide such as tetrabutylammonium bromide. In the present invention, when X is a hydroxyl group, the reaction of the polymer of the formula (II) with the compound of the formula (IV) is not particularly limited with respect to the amount of the phase transfer catalyst. Preferably, the polymer of formula (II) and the phase transfer catalyst are used in an amount such that the molar ratio of monomer units to phase transfer catalyst in the polymer of formula (II) is from 1:0.01 to 1:0.05. It is particularly preferred that the polymer of formula (II) and the phase transfer catalyst are used in an amount such that the molar ratio of monomer units to phase transfer catalyst contained in the polymer of formula (II) is from 1:0.01 to 1:0.02.

In the present invention, when X is a hydroxyl group, the reaction of the polymer of the formula (II) with the compound of the formula (IV) generally ensures that the polymer of the formula (II) is sufficiently reacted. Accordingly, the polymer of formula (II) and the compound of formula (IV) are used in an amount such that the molar ratio of the monomer unit of the polymer of formula (II) to the compound of formula (IV) is generally from 1:1 to 1:2. Preferably, the polymer of formula (II) and the compound of formula (IV) are used in an amount such that the molar ratio of monomer units of formula (II) to compound of formula (IV) is from 1:1.5 to 1:2.

In the present invention, when X is a hydroxyl group, the reaction of the polymer of the formula (II) with the compound of the formula (IV) is usually carried out in a solution. There is no particular limitation on the choice of the solvent as long as the respective reactants can be dissolved. Advantageously, the reaction of the polymer of formula (II) with a compound of formula (IV) is carried out in the presence of an organic solvent. Preferably, the organic solvent is one or more selected from the group consisting of ethanol, acetone, ethyl acetate, dichloromethane, and chloroform. It is particularly preferred that the organic solvent is one selected from the group consisting of ethanol and acetone.

In the present invention, when X is a hydroxyl group, the reaction of the polymer of the formula (II) with the compound of the formula (IV) is required for the reaction conditions such as temperature and pressure. Preferably, the reaction is carried out at 60-80 °C. It is especially preferred that the reaction be carried out at 60-70 °C. The reaction time is advantageously from 12 to 15 hours. The reaction pressure is advantageously atmospheric.

By infrared characterization of the prepared product, it is observed whether the hydroxyl front in the vicinity of 3500 cm ^-1 in the infrared spectrum is weakened or even disappeared or the introduction of the oxetane group is judged whether the formula (I) of the present invention is obtained. The polymer was confirmed by ¹ H-NMR.

By way of example, when X is a halogen, the preparation of a polymer of formula (I) by reaction of a polymer of formula (II) with a compound of formula (III) can generally be carried out as follows:

Step 1): mixing the polymer of formula (II) and a basic catalyst in a solvent to obtain a mixture;

Step 2): gradually adding a compound of the formula (III) to the mixture obtained in the step 1) to carry out a reaction;

Step 3): After completion of the reaction, the mixture is extracted, dried, and the solvent is evaporated under reduced pressure to give a solid, which is washed, filtered, and dried to give a polymer of the formula (I).

The operation of the step 1) can be carried out by first adding a polymer of the formula (II), stirring, introducing nitrogen gas, and then adding a basic catalyst to obtain a mixture.

The operation of the step 2) can be carried out by slowly dropwise adding the compound of the formula (III) at 50 to 70 ° C in the mixture obtained in the step 1), and carrying out the reaction for 12 to 15 hours.

The operation of the step 3) can be carried out as follows: after completion of the reaction, the mixture is separated by adding water and dichloromethane, and the organic phase is dried over MgSO ₄ , and the solvent is evaporated under reduced pressure to give a solid, washed, filtered and dried to give the formula (I) polymer.

By way of example, when X is a hydroxy group, the preparation of the polymer of formula (I) can generally be carried out as follows:

Step 1 '): in solvent A, p-toluenesulfonyl chloride is added to obtain a mixture;

Step 2'): gradually adding a compound of the formula (III) to the mixture obtained in the step 1') to carry out a reaction;

Step 3'): After completion of the reaction, the solid is precipitated by adding water, filtered, washed and dried to obtain a compound of the formula (IV);

Step 4'): mixing the polymer of the formula (II) with a basic catalyst and a phase transfer catalyst in a solvent B to obtain a mixture;

Step 5'): gradually adding a compound of the formula (IV) to the mixture obtained in the step 4') to carry out a reaction;

Step 6'): After completion of the reaction, extraction, drying, and distillation under reduced pressure to give a solid, which is washed, filtered, and dried to give a polymer of formula (I).

The operation of the step 1') can be carried out by adding p-toluenesulfonyl chloride in a solvent A, stirring and dissolving, and introducing nitrogen gas to obtain a mixture.

The operation of the step 2') can be carried out by gradually adding the compound of the formula (III) to the mixture obtained in the step 1') and reacting in an ice water bath for 2-3 hours.

The operation of the step 3') can be carried out as follows: after completion of the reaction, stirring with ice water to precipitate a solid, filtering, washing, and vacuum drying to obtain a compound of the formula (IV).

The operation of the step 4') can be carried out by first adding a polymer of the formula (II) in a solvent B, stirring, introducing nitrogen gas, and further adding a basic catalyst and a phase transfer catalyst to obtain a mixture.

The operation of the step 5') can be carried out by gradually adding the compound of the formula (IV) obtained in the step 3') to the mixture obtained in the step 4'), and reacting at 60 to 70 ° C for 12 to 15 hours.

The operation of the step 6') can be carried out as follows: after completion of the reaction, water and dichloromethane are separated and the organic phase is dried over MgSO ₄ , and the solvent is evaporated under reduced pressure to give a solid, which is washed, filtered and dried to give the formula (I) )polymer.

According to still another aspect of the present invention, there is provided the use of a polymer of the formula (I) according to the invention as a film-forming resin in a photoresist. When the polymer of the formula (I) of the present invention is used as a film-forming resin for a photoresist, polypara-hydroxystyrene is used as a main structure, and polypara-hydroxystyrene itself is synthesized by addition polymerization, and can be controlled by a cation. The living polymerization method obtains a resin having a high molecular weight and a narrow molecular weight distribution, and the poly-p-hydroxystyrene has excellent ultraviolet light transmittance, and the high molecular weight, narrow molecular weight distribution, and good ultraviolet light transmittance are all characterized. It is beneficial to improve the resolution of the photoresist; there are a large number of benzene rings in the resin structure, and the rigidity of the benzene ring makes the resin have good etching resistance; the oxetane group and the oxetane group are introduced into the resin. The group can undergo cationic photopolymerization, complete photocuring, no oxygen inhibition, so the polymerization reaction is not easy to terminate, and the polymerization can be continued in the dark, and a crosslinked network is easily formed in the exposed area, thereby obtaining a high-resolution lithographic pattern; Another advantage of the heterocyclic butane resin is its high viscosity, so that the resulting film adheres well to the substrate and a thicker photoresist film can be obtained.

According to a final aspect of the invention, there is provided a photoresist comprising the polymer of formula (I) of the invention as a film-forming resin.

In general, the photoresist of the present invention consists essentially of the following components: a polymer of formula (I) as a film-forming resin, a photoacid generator, a photopolymerizable monomer, a basic additive, a sensitizer, and light. Glue solvent. Preferably, the mass ratio of the film-forming resin, photoacid generator, photopolymerizable monomer, basic additive, sensitizer, and photoresist solvent is (30-40):(1-4): (20-25): (1-2): (0-2): (40-50). More preferably, the mass ratio of the film-forming resin, photoacid generator, photopolymerizable monomer, basic additive, sensitizer and photoresist solvent is 35:3.0:25:1.5:1.5:50 . By "substantially" herein is meant that at least 90% by weight, more preferably at least 95% by weight, especially at least 98% by weight, in particular at least 99% by weight, of the total weight of the photoresist is from the formula (I) as a film-forming resin. A polymer, a photoacid generator, a photopolymerizable monomer, a basic additive, a sensitizer, and a photoresist solvent.

In the present invention, the photoresist film-forming resin is any one or more of the polymers of the formula (I).

According to the invention, it is preferred that the photoacid generator is any one or more of an iodonium salt, a sulfonium salt and a heterocyclic acid generator. More preferably, the iodonium salt acid generator, the sulfonium salt acid generator and the heterocyclic acid generator have the following general formulae (V), (VI) and (VII):

among them

R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently phenyl, halophenyl, nitrophenyl, C ₆ -C ₁₀ aryl or C ₁ -C ₁₀ alkyl substituted benzoyl;

Y, Z are non-nucleophilic anions such as triflate, BF ₄ ^- , ClO ₄ ^- , PF ₆ ^- , AsF ₆ ^- or SbF ₆ ^- .

According to the invention, it is preferred that the photopolymerizable monomer is N-vinylpyrrolidone, hydroxyethyl methacrylate or a mixture thereof.

According to the invention, it is preferred that the basic additive is a tertiary amine and/or a quaternary amine, and more preferably any one or more of triethanolamine, trioctylamine and tributylamine.

It is preferred according to the invention that the sensitizer is a sensitizer sensitive to a specific wavelength, such as 2,4-diethylthiazinone, 9-oxime methanol and 1-[(2,4-xylene) Any one or more of azo]-2-naphthol.

According to the invention, it is preferred that the photoresist solvent is any one or more of cyclopentanone, γ-butyrolactone and ethyl acetate.

The beneficial effect of the polymer of the formula (I) of the invention as a film-forming resin of a photoresist is that polypara-hydroxystyrene is used as a main structure, and polypara-hydroxystyrene itself is synthesized by polyaddition reaction, and a cation can be used. The method of controlled living polymerization obtains a resin having a high molecular weight and a narrow molecular weight distribution, and the poly(p-hydroxystyrene) has excellent ultraviolet light transmittance, and high molecular weight, narrow molecular weight distribution, and good ultraviolet light transmittance are all characterized. It is beneficial to improve the resolution of the photoresist; there are a large number of benzene rings in the resin structure, and the rigidity of the benzene ring makes the resin have good etching resistance; the oxetane group and oxetane are introduced into the resin. The group can undergo cationic photopolymerization, complete photocuring, no oxygen inhibition, so the polymerization reaction is not easy to terminate, and the polymerization can be continued in the dark, and a crosslinked network is easily formed in the exposed area, thereby obtaining a high-resolution lithographic pattern; Another advantage of the oxetane resin is its high viscosity, so that the resulting film adheres well to the substrate and a thicker photoresist film can be obtained.

Example

The invention is further illustrated by the following examples, which are not to be construed as limiting the scope of the invention.

The characterization and detection methods involved in the following examples are as follows:

1. Infrared spectrum characterization method

The infrared spectrum was measured by Shimadzu IRAffinity Fourier Transform Infrared Spectrometer, the scanning range was 4000-400 cm ^-1 , and the samples were processed by KBr tableting.

2. ¹ H NMR spectrum characterization method

¹ H NMR was measured by a Bruker Avame PRX400 nuclear magnetic resonance spectrometer. The chemical shift was expressed in ppm. The solvent was deuterated chloroform, the internal standard was tetramethylsilane, the scanning width was 400 MHz, and the number of scans was 16 times.

3. Ultraviolet absorption spectrometry

The sample was formulated into a solution having a concentration of 30 ppm using acetonitrile as a solvent, and the ultraviolet absorption spectrum was measured by a Shimadzu UV-2450 ultraviolet-visible spectrophotometer. The measurement range was 200-400 nm, the resolution was 0.1 nm, and the band width was 0.1-5 nm. , stray light is 0.015% or less.

Example 1: Poly 4-((3-ethyloxetan-3-yl)methoxy)-3-methylstyrene

50 mL of acetone was used as a solvent, and 13.4 g of poly-m-methyl-p-hydroxystyrene (number average molecular weight: 2,680, n=20) (0.1 mol of repeating unit) was added to the solvent, and electric stirring was carried out, nitrogen gas was introduced, and 8.28 g of potassium carbonate was added ( 0.06 mol), the reaction temperature of the obtained mixture was controlled at 60 ° C, and 24.2 g of 3-ethyl-3-chloromethyloxetane (0.18 mol) was slowly added dropwise through a constant pressure dropping funnel, and dropped in 0.5 h. After the addition was completed, the resulting reaction mixture was allowed to react at 60 ° C for 12 h. After reaction completion, 100mL of methylene chloride was added, extracted with water, the organic layer was dried with MgSO _4, the solvent was distilled off under reduced pressure, to give the solid product was washed three times with water, filtered and dried to give the product, was analyzed to be the title compound.

The nuclear magnetic data of the obtained product is as follows (d-CDCl ₃ ): δ 1.87 methylene chloride in the polystyrene chain; δ 2.76 methine in the polystyrene chain; δ 6.57, 6.82, 6.84 on the benzene ring; δ 2.35 phenyl ring-linked methyl group; δ 3.86 linked to methylene group of phenoxy group and oxetane; methylene group in δ 4.65 oxetane ring; δ 1.25 oxetane a methylene group in an ethyl group of an alkyl group; a methyl group in an ethyl group of δ 0.96 oxetane.

Infrared spectroscopy results showed that no hydroxyl stretching vibration peak was detected at 3100 cm ^-1 -3500 cm ^-1 , and characteristic absorption peaks of four-membered cyclic ether appeared at 976, 867 and 834 cm ^-1 .

Ultraviolet absorption spectroscopy results: the maximum absorption wavelength is 223 nm, there is no ultraviolet absorption peak above 223 nm, and there is good light transmission in the ultraviolet light region above 223 nm.

Example 2: Poly 4-((3-methoxyoxetan-3-yl)methoxy)-3-ethoxystyrene

Take 50 mL of ethanol as a solvent, and add 16.4 g of poly-3-ethoxy-4-hydroxystyrene (number average molecular weight 4100, n=25) (0.1 mol repeating unit) to the solvent, electric stirring, nitrogen gas, and added Potassium hydroxide 5.6 g (0.1 mol), the reaction temperature of the obtained mixture was controlled at 60 ° C, and 27.3 g of 3-methoxy-3-chloromethyloxetane (0.2) was slowly added dropwise through a constant pressure dropping funnel. Mol), the dropwise addition was completed within 0.5 h, and then the resulting reaction mixture was allowed to react at 60 ° C for 12 h. After reaction completion, 100mL of methylene chloride was added, extracted with water, the organic layer was dried with MgSO _4, the solvent was distilled off under reduced pressure, to give the solid product was washed three times with water, filtered and dried to give the product, was analyzed to be the title compound.

The nuclear magnetic data of the obtained product is as follows (d-CDCl ₃ ): δ 1.87 methylene chloride in the polystyrene chain; δ 2.76 methine in the polystyrene chain; δ 6.53, 6.58, 6.60 H on the benzene ring; δ 3.98 methylene group in the ethoxy group of the benzene ring; δ 1.33 methyl group in the ethoxy group of the benzene ring; δ 4.03 to the methylene group of the phenoxy group and the oxetane; δ4 a methylene group in a .82 oxetane ring; a methyl group in a methoxy group of δ 3.24 oxetane.

Infrared spectroscopy results showed that no hydroxyl stretching vibration peak was detected at 3100 cm ^-1 -3500 cm ^-1 , and characteristic absorption peaks of four-membered cyclic ether appeared at 970, 865 and 832 cm ^-1 .

Ultraviolet absorption spectroscopy results: the maximum absorption wavelength is 227 nm, there is no ultraviolet absorption peak above 227 nm, and there is good light transmission in the ultraviolet light region above 227 nm.

Example 3: Poly 4-((3-methyloxetan-3-yl)methoxy)-2-chloromethyl-5-ethylstyrene

50 mL of acetone was used as a solvent, and 19.7 g of poly-2-chloromethyl-4-hydroxy-5-ethylstyrene (number average molecular weight 5895, n=30) (0.1 mol of repeating unit) was added to the solvent, and electric stirring was carried out. Under nitrogen, 8.28 g (0.08 mol) of sodium carbonate was added, the reaction temperature of the obtained mixture was controlled at 60 ° C, and 21.7 g of 3-methyl-3-chloromethyloxetane was slowly added dropwise through a constant pressure dropping funnel. The alkane (0.18 mol) was added dropwise over 0.5 h, after which the resulting reaction mixture was reacted at 60 ° C for 12 h. After reaction completion, 100mL of methylene chloride was added, extracted with water, the organic layer was dried with MgSO _4, the solvent was distilled off under reduced pressure, to give the solid product was washed three times with water, filtered and dried to give the product, was analyzed to be the title compound.

The nuclear magnetic data of the obtained product is as follows (d-CDCl ₃ ): methylene group in the polystyrene chain of δ 1.87; methine in the δ 2.76 polystyrene chain; δ 6.64, H on the 6.88 benzene ring; δ 2. 59 methylene group in the phenyl ring of ethyl; δ 1.24 benzyl ring in the ethyl group; δ 4.64 benzene ring chloromethyl; δ 3.86 linked phenoxy and oxetane Methylene of alkane; methylene group in δ 4.65 oxetane ring; methyl group of δ 1.16 oxetane.

Infrared spectroscopy results showed that no hydroxyl stretching vibration peak was detected at 3100 cm ^-1 -3500 cm ^-1 , and characteristic absorption peaks of four-membered cyclic ether appeared at 978, 864 and 836 cm ^-1 .

Ultraviolet absorption spectroscopy results: the maximum absorption wavelength is 221 nm, there is no ultraviolet absorption peak above 221 nm, and there is good light transmission in the ultraviolet light region above 221 nm.

Example 4: Poly 4-((3-ethyloxetan-3-yl)methoxy)-3-cyclopropylstyrene

Take 50mL of ethanol as solvent, add 16g of poly-3-cyclopropyl-4-hydroxystyrene (number average molecular weight 6400, n=40) (0.1mol repeating unit) to the solvent, stir it electrically, add nitrogen, add hydrogen 3.2 g (0.08 mol) of sodium oxide, the reaction temperature of the obtained mixture was controlled at 60 ° C, and 24.2 g of 3-ethyl-3-chloromethyloxetane (0.18 mol) was slowly added dropwise through a constant pressure dropping funnel. After the dropwise addition was completed within 0.5 h, the resulting reaction mixture was allowed to react at 60 ° C for 12 h. After reaction completion, 100mL of methylene chloride was added, extracted with water, the organic layer was dried with MgSO _4, the solvent was distilled off under reduced pressure, to give the solid product was washed three times with water, filtered and dried to give the product, was analyzed to be the title compound.

The nuclear magnetic data of the obtained product is as follows (d-CDCl ₃ ): δ 1.87 methylene group in the polystyrene chain; δ 2.76 methine in the polystyrene chain; δ 6.61, 6.84, 6.89 on the benzene ring; a methylene group in a cyclopropyl group of δ 0.51 benzene ring; a methine group in a cyclopropyl group of δ 1.50 benzene ring; a methylene group of δ 3.86 linking a phenoxy group and an oxetane; a methylene group in the δ 4.65 oxetane ring; a methylene group in the ethyl group of δ 1.25 oxetane; and a methyl group in the ethyl group of δ 0.96 oxetane.

Infrared spectroscopy results showed that no hydroxyl stretching vibration peak was detected at 3100 cm ^-1 -3500 cm ^-1 , and characteristic absorption peaks of four-membered cyclic ether appeared at 974, 866 and 834 cm ^-1 .

Ultraviolet absorption spectroscopy results: the maximum absorption wavelength is 225 nm, there is no ultraviolet absorption peak above 225 nm, and there is good light transmission in the ultraviolet light region above 225 nm.

Example 5: Poly 4-((3-cyclopropyloxetan-3-yl)methoxy)-3,5-di-chloromethylstyrene

150 mL of pyridine was used as a solvent, and 53.34 g of p-toluenesulfonyl chloride (0.28 mol) was added to the solvent, and the mixture was stirred under nitrogen, and nitrogen gas was added thereto, and 25.6 g of 3-cyclopropyl-3-hydroxymethyloxalate was added dropwise thereto in an ice water bath. Cyclobutane (0.2 mol) was added dropwise over 0.5 h, and the reaction was continued for 2 h. After completion of the reaction, it was stirred with ice water to precipitate a solid, which was filtered, washed, and dried to give the product, 3-cyclopropyl oxetane-3-ylmethyl p-toluenesulfonate.

Take 50 mL of acetone as a solvent, and add 21.7 g of poly-3,5-di-chloromethyl-4-hydroxystyrene (number average molecular weight 4340, n=20) (0.1 mol repeating unit) to the solvent, and electrically stir. Under nitrogen, 5.6 g (0.1 mol) of potassium hydroxide and 0.32 g (0.001 mol) of tetrabutylammonium bromide were added, and the reaction temperature of the obtained mixture was controlled at 60 ° C, and 42.3 g of 3-cyclopropyl p-toluenesulfonate was gradually added. The oxetane-3-ylmethyl ester (0.15 mol) was added dropwise over 0.5 h, after which the resulting reaction mixture was reacted at 60 ° C for 12 h. After reaction completion, 100mL of methylene chloride was added, extracted with water, the organic layer was dried with MgSO _4, the solvent was distilled off under reduced pressure, to give the solid product was washed three times with water, filtered and dried to give the product, was analyzed to be the title compound.

The nuclear magnetic data of the obtained product are as follows (d-CDCl ₃ ): methylene group in δ 1.87 polystyrene chain; methine in δ 2.76 polystyrene chain; H on δ 7.02 benzene ring; δ 4.64 benzene Cyclomethylmethyl; δ3.86 methylene group linking phenoxy and oxetane; methylene group in δ4.65 oxetane ring; methylene group in δ 0.18 cyclopropyl group Base; δ 0.21 methine in cyclopropyl.

Infrared spectroscopy results showed that no hydroxyl stretching vibration peak was detected at 3100 cm ^-1 -3500 cm ^-1 , and characteristic absorption peaks of four-membered cyclic ether appeared at 971, 869 and 835 cm ^-1 .

Ultraviolet absorption spectroscopy results: the maximum absorption wavelength is 223 nm, there is no ultraviolet absorption peak above 223 nm, and there is good light transmission in the ultraviolet light region above 223 nm.

Example 6: Poly 4-((3-methoxyoxetan-3-yl)methoxy)-2-methyl-5-cyclopropylstyrene

150 mL of pyridine was used as a solvent, and 57.15 g of p-toluenesulfonyl chloride (0.3 mol) was added to the solvent, and the mixture was stirred under nitrogen, and nitrogen gas was added thereto, and 23.6 g of 3-methoxy-3-hydroxymethyloxalate was added dropwise thereto in an ice water bath. Cyclobutane (0.2 mol) was added dropwise over 0.5 h, and the reaction was continued for 2 h. After completion of the reaction, the mixture was stirred with ice water to precipitate a solid, which was filtered, washed and dried to give the product, which was 3-methoxy oxetane-3-ylmethyl p-toluenesulfonate.

Taking 50 mL of ethanol as a solvent, 17.4 g of poly-2-methyl-4-hydroxy-5-cyclopropylstyrene (number average molecular weight 5220, n=30) (0.1 mol of repeating unit) was added to the solvent, and electric stirring was carried out. Under nitrogen, 8.28 g (0.06 mol) of potassium carbonate and 0.64 g (0.002 mol) of tetrabutylammonium bromide were added, and the reaction temperature of the obtained mixture was controlled at 60 ° C, and 48.96 g of 3-methoxyl p-toluenesulfonic acid was gradually added. The oxetane-3-ylmethyl ester (0.18 mol) was added dropwise over 0.5 h, after which the resulting reaction mixture was reacted at 60 ° C for 12 h. After reaction completion, 100mL of methylene chloride was added, extracted with water, the organic layer was dried with MgSO _4, the solvent was distilled off under reduced pressure, to give the solid product was washed three times with water, filtered and dried to give the product, was analyzed to be the title compound.

The nuclear magnetic data of the obtained product is as follows (d-CDCl ₃ ): methylene group in δ 1.87 polystyrene chain; methine in δ 2.76 polystyrene chain; δ 6.41, 6.77 on the benzene ring; δ 2. 35 phenyl ring-linked methyl group; δ 0.51 benzyl ring-bonded methylene group in cyclopropyl group; δ 1.50 phenyl ring-linked methine group in cyclopropyl group; δ4.03 linked phenoxy group and oxa group Methylene group of cyclobutane; methylene group in δ 4.82 oxetane ring; methoxy group of δ 3.25 oxetane.

Infrared spectroscopy results showed that no hydroxyl stretching vibration peak was detected at 3100 cm ^-1 -3500 cm ^-1 , and characteristic absorption peaks of four-membered cyclic ether appeared at 970, 862 and 830 cm ^-1 .

Ultraviolet absorption spectroscopy results: the maximum absorption wavelength is 220 nm, there is no ultraviolet absorption peak above 220 nm, and there is good light transmission in the ultraviolet region above 220 nm.

Example 7: Poly 4-((3-methyloxetan-3-yl)methoxy)-3-propoxystyrene

Taking 150 mL of pyridine as a solvent, 49.53 g of p-toluenesulfonyl chloride (0.26 mol) was added to the solvent, and the mixture was stirred under nitrogen, and nitrogen gas was added thereto, and 20.4 g of 3-methyl-3-hydroxymethyloxycyclohexane was added dropwise thereto in an ice water bath. Butane (0.2 mol) was added dropwise in 0.5 h, and the reaction was continued for 2 h. After completion of the reaction, the mixture was stirred with ice water to precipitate a solid, which was filtered, washed, and dried to give the product, 3-methyloxetan-3-ylmethyl p-toluenesulfonate.

50 mL of ethanol was used as a solvent, and 17.8 g of poly-3-propoxy-4-hydroxystyrene (number average molecular weight 6230, n=35) (0.1 mol of repeating unit) was added to the solvent, and electric stirring was carried out, and nitrogen gas was introduced thereto. 10.6 g (0.1 mol) of sodium carbonate, 0.64 g (0.002 mol) of tetrabutylammonium bromide, the reaction temperature of the obtained mixture was controlled at 60 ° C, and gradually added 51.2 g of 3-methyloxetane p-toluenesulfonate. 3-methylmethyl ester (0.2 mol) was added dropwise over 0.5 h, after which the resulting reaction mixture was reacted at 60 ° C for 12 h. After reaction completion, 100mL of methylene chloride was added, extracted with water, the organic layer was dried with MgSO _4, the solvent was distilled off under reduced pressure, to give the solid product was washed three times with water, filtered and dried to give the product, was analyzed to be the title compound.

The nuclear magnetic data of the obtained product is as follows (d-CDCl ₃ ): methylene group in δ 1.87 polystyrene chain; methine in δ 2.76 polystyrene chain; δ 6.53, 6.58 on benzene ring; δ 3. a methylene group adjacent to oxygen in a phenyl ring-linked propoxy group; a methylene group adjacent to a methyl group in a propyl 1.75 benzene ring-linked propoxy group; a δ 0.96 phenyl ring-linked propoxy group Methyl group; δ 3.86 linking methylene group of phenoxy group and oxetane; methylene group in δ 4.65 oxetane ring; methyl group of δ 1.16 oxetane.

Infrared spectroscopy results showed that no hydroxyl stretching vibration peak was detected at 3100 cm ^-1 -3500 cm ^-1 , and characteristic absorption peaks of four-membered cyclic ether appeared at 978, 867 and 832 cm ^-1 .

Ultraviolet absorption spectrum results: the maximum absorption wavelength is 226 nm, there is no ultraviolet absorption peak above 226 nm, and there is good light transmission in the ultraviolet light region above 226 nm.

Example 8: Poly 4-((3-ethyloxetan-3-yl)methoxy)-2-methyl-5-methoxystyrene

150 mL of pyridine was used as a solvent, and 45.72 g of p-toluenesulfonyl chloride (0.24 mol) was added to the solvent, and the mixture was stirred under nitrogen, and nitrogen was added thereto, and 23.2 g of 3-ethyl-3-hydroxymethyloxycyclohexane was added dropwise thereto in an ice water bath. Butane (0.2 mol) was added dropwise in 0.5 h, and the reaction was continued for 2 h. After completion of the reaction, the mixture was stirred with ice water to precipitate a solid, which was filtered, washed and dried to give the product, 3-ethyloxetan-3-ylmethyl p-toluenesulfonate.

50 mL of acetone was used as a solvent, and 16.4 g of poly-2-methyl-4-hydroxy-5-methoxystyrene (number average molecular weight: 6560, n=40) (0.1 mol of repeating unit) was added to the solvent, and electric stirring was carried out. Under nitrogen, 2.4 g (0.06 mol) of sodium hydroxide and 0.32 g (0.001 mol) of tetrabutylammonium bromide were added, and the reaction temperature of the obtained mixture was controlled at 60 ° C, and 40.5 g of p-toluenesulfonic acid 3-B was gradually added. The oxetane-3-ylmethyl ester (0.15 mol) was added dropwise over 0.5 h, after which the resulting reaction mixture was reacted at 60 ° C for 12 h. After reaction completion, 100mL of methylene chloride was added, extracted with water, the organic layer was dried with MgSO _4, the solvent was distilled off under reduced pressure, to give the solid product was washed three times with water, filtered and dried to give the product, was analyzed to be the title compound.

The nuclear magnetic data of the obtained product are as follows (d-CDCl ₃ ): methylene group in the polystyrene chain of δ 1.87; methine in the δ 2.76 polystyrene chain; δ 6.38, H on the 6.41 benzene ring; δ 2. 35 phenyl ring-linked methyl group; δ 3.73 benzene ring-linked methoxy group; δ 3.86 linked phenoxy group and oxetane methylene group; δ 4.65 oxetane ring in the methylene group a methylene group in an ethyl group of δ 1.25 oxetane; a methyl group in an ethyl group of δ 0.96 oxetane.

Infrared spectroscopy results showed that no hydroxyl stretching vibration peak was detected at 3100 cm ^-1 -3500 cm ^-1 , and characteristic absorption peaks of four-membered cyclic ether appeared at 977, 861 and 840 cm ^-1 .

Ultraviolet absorption spectroscopy results: the maximum absorption wavelength is 228 nm, there is no ultraviolet absorption peak above 228 nm, and there is good light transmission in the ultraviolet light region above 228 nm.

Example 9

Four negative chemically amplified photoresists were prepared as follows: 30 g of each of the polymers prepared in Examples 1-4, 2 g of 3-nitrophenyl. diphenylthio hexafluorophosphate, 25 g of N were prepared. -vinylpyrrolidone, 1.8 g of trioctylamine, 1 g of 9-oxime methanol and 50 g of ethyl acetate, the above materials are mixed and thoroughly stirred to completely dissolve, and filtered through a 0.45 μm polytetrafluoroethylene microporous membrane to obtain Four new negative chemical amplification photoresists.

Example 10

Four negative chemically amplified photoresists were prepared as follows: 40 g of each of the polymers prepared in Examples 5-8, 3 g of bis(4-tert-butylphenyl)iodotrifluoromethanesulfonate, 20 g of hydroxyethyl methacrylate, 1.5 g of triethanolamine, 1.5 g of 2,4-diethylthiaxanone and 50 g of cyclopentanone, the above materials were mixed and thoroughly stirred to completely dissolve, and passed through 0.45 μm of polytetrafluoroethylene. Four kinds of new negative chemical amplification photoresists can be obtained by filtering the ethylene microporous membrane.

Example 11

The four negative chemically amplified photoresists obtained in the above Example 9 were respectively coated on a 6-inch single crystal silicon wafer by spin coating (rotation speed: 4000 rpm), baked at 90 ° C for 2 minutes, and cooled to room temperature, and then coated. A good silicon wafer was exposed to an exposure machine having a wavelength of 365 nm, and after baking, it was baked at 110 ° C for 2 minutes, and developed with a propylene glycol methyl ether acetate aqueous solution as a developing solution for 60 s to obtain a lithographic image. The lithographic images of the photoresists obtained in the polymers obtained in Examples 1-4 are shown in Figures 1(a)-(d), respectively.

Example 12

The four negative chemically amplified photoresists obtained in the above Example 10 were respectively coated on a 6-inch single crystal silicon wafer by spin coating (rotation speed: 4000 rpm), baked at 100 ° C for 2 minutes, and cooled to room temperature, and then coated. A good silicon wafer was exposed to an exposure machine having a wavelength of 248 nm, and after baking, it was baked at 100 ° C for 2 minutes, and developed with a propylene glycol methyl ether acetate aqueous solution as a developing solution for 50 s to obtain a lithographic image. The lithographic images of the photoresists obtained in Examples 5-8 were as shown in Figures 2(a)-(d), respectively.

It can be seen from Fig. 1 that the polymer obtained in the examples 1-4 is used as a film-forming resin, and the obtained photoresist is prepared, and after exposure, development and the like, a clear pattern with a diameter of about 30 μm can be obtained, and the resolution is high. The graphics are arranged neatly, the edges are complete, and there is no glue or residue.

It can be seen from Fig. 2 that the polymer obtained in the examples 5-8 is used as a film-forming resin, and the obtained photoresist is prepared, and after exposure, development and the like, a film having a relatively large thickness can be obtained, and the obtained lithographic pattern can be obtained. It has a three-dimensional structure with a thickness of up to about 70μm and an aspect ratio of up to 1:1.

The polymer prepared in the above examples is used for the negative chemical amplification of the photoresist, based on the cationic photocuring of the oxetane group, using a chemical amplification technique, with the poly(p-hydroxystyrene) structure as the main body. Its high molecular weight, narrow molecular weight distribution, and good UV light transmission make the photoresist have good resolution. The introduction of the oxetane structure makes the resin easily form a crosslinked network in the exposed region, thereby obtaining a high-resolution lithographic pattern; in addition, the viscosity of the oxetane resin is large, so that the obtained film is on the substrate. It has good adhesion and easy to obtain thick photoresist film. After exposure and development, a clear pattern with a diameter of 30μm can be obtained, and the film thickness can reach 70μm, which has a good application prospect in the field of thick film photoresist.

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Claims (13)

1. The polymer of the following formula (I):

   

   among them:

   R _a -R _d are each independently selected from H, halogen, C ₁ -C ₆ alkyl, halogenated C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, halogenated C ₁ -C ₆ alkane a group of an oxy group, a C ₃ -C ₁₂ cycloalkyl group and a halogenated C ₃ -C ₁₂ cycloalkyl group;

   R is selected from the group consisting of H, halogen, C ₁ -C ₆ alkyl, halogenated C ₁ -C ₆ alkyl, C ₁ -C ₆ hydroxyalkyl, C ₁ -C ₆ alkoxy, and halogenated C ₁ -C _a group of ₆ alkoxy groups;

   n is a number of 20-40.
2. The polymer according to claim 1 wherein

   R _a -R _d are each independently selected from the group consisting of H, chlorine, bromine, C ₁ -C ₄ alkyl, chloro C ₁ -C ₄ alkyl, bromo C ₁ -C ₄ alkyl, C ₁ -C ₄ a group of alkoxy, chloro C ₁ -C ₄ alkoxy, bromo C ₁ -C ₄ alkoxy and C ₃ -C ₆ cycloalkyl, preferably R _a -R _d are each independently selected from a group of H, C ₁ -C ₄ alkyl, halo C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, cyclopropyl, cyclobutyl and cyclopentyl; and/or

   R is selected from the group consisting of H, chlorine, bromine, C ₁ -C ₄ alkyl, chloro C ₁ -C ₄ alkyl, bromo C ₁ -C ₄ alkyl, C ₁ -C ₄ hydroxyalkyl, C ₁ - a group of a C ₄ alkoxy group, a chloro C ₁ -C ₄ alkoxy group, a brominated C ₁ -C ₄ alkoxy group and a C ₃ -C ₆ cycloalkyl group, preferably R is H, chlorine, C ₁ - C ₄ alkyl, chloro C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, cyclopropyl, cyclobutyl or cyclopentyl; and/or

   n is a number from 24 to 36, preferably a number from 25 to 30.
3. A process for the preparation of a polymer of formula (I) according to claim 1 or 2, wherein, when X is a halogen, the polymer of formula (II) is reacted with a compound of formula (III); when X is a hydroxy group, The compound of formula (III) is first reacted with p-toluenesulfonyl chloride to give a compound of formula (IV), which is then reacted with a polymer of formula (II).

   

   Wherein R _a -R _d , R and n are each as defined in claim 1 or 2, and X is a halogen, preferably chlorine or bromine, or X is a hydroxyl group.
4. The method according to claim 3, wherein when X is a halogen, the reaction of the polymer of the formula (II) with the compound of the formula (III) is carried out in the presence of a basic catalyst, preferably the basic catalyst is selected from the group consisting of NaOH, KOH, Na. ₂ or more of CO ₃ and K ₂ CO ₃ , preferably K ₂ CO ₃ and/or KOH; when X is a hydroxyl group, the reaction of the polymer of formula (II) with the compound of formula (IV) is alkaline The catalyst is preferably carried out in the presence of a catalyst, preferably one or more selected from the group consisting of NaOH, KOH, Na ₂ CO ₃ and K ₂ CO ₃ , preferably K ₂ CO ₃ and/or KOH.
5. The method according to claim 3 or 4, wherein, when X is a halogen, the polymer of the formula (II) and the compound of the formula (III) are used in an amount such that the monomer unit of the polymer of the formula (II) and the compound of the formula (III) The molar ratio is from 1:1 to 1:3, preferably from 1:1.8 to 1:2; when X is a hydroxyl group, the polymer of formula (II) and the compound of formula (IV) are used in an amount such that the polymer of formula (II) The molar ratio of the monomer units contained to the compound of the formula (IV) is from 1:1 to 1:2, preferably from 1:1.5 to 1:2.
6. The method according to any one of claims 3 to 5, wherein, when X is a halogen, the polymer of the formula (II) and the basic catalyst are used in an amount such that the monomer unit and the basic catalyst contained in the polymer of the formula (II) The molar ratio is 1:0.1-1:1, preferably 1:0.6-1:1; when X is a hydroxyl group, the amount of the polymer of formula (II) and the basic catalyst are such that the polymer of formula (II) is contained. The molar ratio of the monomer unit to the basic catalyst is from 1:0.1 to 1:1, preferably from 1:0.5 to 1:1.
7. The method according to any one of claims 3 to 6, wherein when X is a halogen, the reaction of the polymer of the formula (II) with the compound of the formula (III) is carried out at 50 to 80 ° C, preferably at 50 to 70 ° C. When X is a hydroxyl group, the reaction of the compound of the formula (III) with p-toluenesulfonyl chloride is carried out at -10 to 10 ° C, preferably at -5 to 5 ° C, and/or the polymer of the formula (II) The reaction of the compound of the formula (IV) is carried out at 60 to 80 ° C, preferably at 60 to 70 ° C.
8. The process according to any one of claims 3 to 7, wherein, when X is a hydroxyl group, the reaction of the polymer of the formula (II) with the compound of the formula (IV) is carried out in the presence of a phase transfer catalyst, preferably the phase transfer catalyst is tetraoxane. An ammonium halide, such as a tetra C ₁ -C ₄ alkyl ammonium halide such as tetrabutylammonium bromide.
9. Use of a polymer of formula (I) according to claim 1 or 2 as a film-forming resin in a photoresist.
10. A photoresist comprising a polymer of formula (I) according to claim 1 or 2 as a film-forming resin.
11. The photoresist according to claim 10, comprising a polymer of the formula (I) according to claim 1 or 2 as a film-forming resin, a photoacid generator, a photopolymerizable monomer, a basic additive, a sensitizer and light a peptizing agent; preferably, the mass ratio of the film-forming resin, photoacid generator, photopolymerizable monomer, basic additive, sensitizer, and photoresist solvent is (30-40): (1-4) :(20-25):(1-2):(0-2):(40-50); more preferably, the film-forming resin, photoacid generator, photopolymerizable monomer, alkaline additive, sensitization The mass ratio of the agent to the photoresist solvent was 35:3.0:25:1.5:1.5:50.
12. The photoresist according to claim 11, wherein said photoacid generator is any one or more of an iodonium salt, a sulfonium salt and a heterocyclic acid generator; preferably said iodonium salt acid generator The sulfonium salt acid generator and the heterocyclic acid generator have the following general formulae (V), (VI) and (VII):

    

    Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently phenyl, halophenyl, nitrophenyl, C ₆ -C ₁₀ aryl or C _{a 1-} C ₁₀ alkyl substituted benzoyl;

    Y, Z are non-nucleophilic anions such as triflate, BF ₄ ^- , ClO ₄ ^- , PF ₆ ^- , AsF ₆ ^- or SbF ₆ ^- .
13. A photoresist according to claim 11 or 12, wherein

    The photopolymerizable monomer is N-vinylpyrrolidone, hydroxyethyl methacrylate or a mixture thereof; and/or

    The basic additive is a tertiary amine and/or a quaternary amine, more preferably any one or more of triethanolamine, trioctylamine and tributylamine; and/or

    The sensitizer is any one or more of 2,4-diethylthiaxanthone, 9-fluorenyl methanol and 1-[(2,4-dimethylphenyl)azo]-2-naphthol Kind; and/or

    The photoresist solvent is any one or more of cyclopentanone, γ-butyrolactone, and ethyl acetate.

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