CN116284517A - A kind of narrow molecular weight distribution and high light transmittance PHS resin and its synthesis method and application - Google Patents

Abstract

The invention discloses a PHS resin with narrow molecular weight distribution and high light transmittance, a synthesis method and application thereof, and a synthesis method and application thereof. The PHS resin provided by the present invention comprises a general structural formula shown in formula (I); obtained by anionic copolymerization. The present invention also provides a photoresist, which includes a film-forming resin; the film-forming resin includes the PHS resin. The PHS resin of the present invention has the advantages of narrow molecular weight distribution, excellent light transmittance, good alkali solubility and high thermal stability, and effectively solves the problems of relatively low sensitivity and high residual film rate of existing photoresists. Meet the needs of the development of the integrated circuit industry.

Description

A kind of narrow molecular weight distribution and high light transmittance PHS resin and its synthesis method and application

technical field

The invention relates to a PHS resin with narrow molecular weight distribution and high light transmittance, a synthesis method and application thereof, and belongs to the field of polymer materials.

Background technique

Photoresist is a key functional material in the photolithography process in the large-scale integrated circuit industry. The film-forming resin contained in it is an important part of the photoresist. The chemical and physical properties of the film-forming resin directly affect the photoresist. Effects of use in the large-scale integrated circuit industry.

Generally speaking, the lower the optical density value of the film-forming resin, the better its light transmittance, the more sensitive it is during exposure, and the lower the residual film rate. One of the very important reference indicators in performance evaluation.

Polyhydroxystyrene (PHS) resin has become the mainstream photoresist component of 248nm because of its good light transmission at 248nm (optical density is 0.22/μm), good alkali solubility and excellent etching resistance. film resin. However, with the increase of integrated circuit density, its processing difficulty is gradually increasing, and higher requirements are put forward for the resolution and optical sensitivity of photoresist. The light transmittance of the existing polyhydroxystyrene (PHS) resin needs to be further improved.

Chinese patent application CN108084331A discloses a bio-based film-forming resin and a photoresist prepared therefrom. The bio-based film-forming resin is prepared by free radical polymerization and alcoholysis of styrene derivatives and cholic acid derivatives. become. This method improves the light transmittance of the film-forming resin by introducing acrylate monomers of cholesteric structure (polycyclic alkanes) into styrene derivatives, but due to the relatively poor heat resistance of acrylate monomers, it is very easy to The cholesteric structure is removed, resulting in large fluctuations in the light transmittance of the film-forming resin, which seriously affects the stability of the photoresist. Moreover, the styrene derivative monomer used in it, due to the strong conjugated structure of the benzene ring, the electron cloud density is relatively concentrated, and its optical density is 0.71/μm, so after copolymerization, it is very easy to cause the light transmission performance of the copolymer resin to decline According to its public records, the light transmittance of the 248nm photoresist made of the film-forming resin obtained by this method is only 0.25/μm.

In addition, another important index to measure the quality of polymers is PDI (olymerdispersity index, polymer dispersion index), which is used to describe the molecular weight distribution of polymers. The molecular weight of a polymer is usually not uniform, and it is essentially a mixture. The average molecular weight is used to describe the molecular weight of a polymer. The average molecular weight can be divided into number average molecular weight, weight average molecular weight and viscosity average molecular weight. The ratio of weight average molecular weight to number average molecular weight called the dispersion index. The larger the PDI, the wider the molecular weight distribution and the poorer the quality; the smaller the PDI, the narrower and more uniform the molecular weight distribution, the better the quality.

However, the existing PHS resins mainly use p-hydroxystyrene or protected acetoxystyrene as polymerizable monomers, and are synthesized by free radical polymerization. Although the resulting PHS resins have high light transmittance, the PDI is too large (PDI≥1.4), the purity is not high.

In view of the above, the present invention is proposed.

Contents of the invention

The purpose of the present invention is to provide a novel PHS resin with narrow molecular weight distribution and excellent light transmittance and its synthesis method and application, which can effectively solve the problem of relatively low sensitivity of existing photoresists, thereby satisfying the needs of the integrated circuit industry. High processing requirements.

To achieve the above object, the present invention provides the following technical solutions:

First aspect, the present invention provides a kind of PHS resin, comprises the structural general formula shown in formula (I):

In the formula:

m, n, p, and q represent the degree of polymerization of repeating unit A, repeating unit B, repeating unit C, and repeating unit D, respectively, where m≥1, n≥1, p≥0 and p/(m+n+p+ q)≤20%, q≥0;

R ₁ represents H, C1-C3 alkyl, C1-C3 alkoxy or C3-C10 cycloalkyl; preferably H, propyl.

R ₃ represents methyl, ethyl, tert-butyl,

k represents the number of substituents R ₁ , and is a number between 0 and 5.

Invention concept of the present invention and formation mechanism are as follows:

The present invention found that the repeating unit A is an aliphatic ring structure. Compared with the benzene ring, there is no conjugated π bond, and its electron cloud distribution is more uniform. In the full wavelength range, its light transmittance cut-off wavelength is lower, so it is introduced In the PHS resin, the optical density of the PHS resin can be significantly reduced; at the same time, it can also achieve anionic polymerization with the monomer with repeating unit B, so that the molecular weight distribution of the PHS resin is narrower.

In addition, on the basis of repeating unit A and repeating unit B, repeating unit C and repeating unit D are further introduced to meet the performance requirements of different photoresist film-forming resins. Among them, the repeating unit C plays the role of further improving the heat resistance of the resin, so that the PHS resin has further advantages in high temperature resistance; and the repeating unit D plays the role of improving the bonding force between the film and the substrate, so that the PHS resin further has a high temperature resistance. Peel strength performance advantage, better performance.

The novel PHS resin obtained by the invention not only has a lower optical density (<0.2/μm), but also has a narrower molecular weight distribution (PDI≤1.2), and also has the advantages of good heat resistance and stable structure.

In formula (I), the ratio of m:(n+p+q)≥0.25; preferably (0.25-1):1. Studies have shown that by reasonably controlling the proportion of cyclohexane monomer added, the effect of monomer A on reducing the optical density of PHS resin can be effectively guaranteed. If the proportion is too low, the advantages of copolymerization cannot be shown.

The weight-average molecular weight of the PHS resin is between 1000-100000, and the PDI≤1.2.

Second aspect, the present invention provides the synthetic method of described PHS resin, comprises the steps:

单体B/>

单体C/>

单体D/>

为原料进行阴离子共聚反应，再对R₂取代基进行脱保护反应，得到所述PHS树脂；Monomer A

Monomer B/>

Monomer C/>

Monomer D/>

Carry out anionic copolymerization reaction as raw material, and then carry out deprotection reaction to _R2 substituent, obtain described PHS resin;

The definitions of R ₁ , R ₃ , and k are the same as in formula (I);

R ₂ represents one or more of methyl, ethyl, tert-butyl, propyl, isopropyl, acetoxy and propionyloxy.

The anionic copolymerization reaction is carried out under the environment of nitrogen circulation.

The temperature of the copolymerization reaction is -75-80°C.

The initiator used in the anionic copolymerization reaction is one or more of propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, lithium chloride, sodium naphthalene, sodium and potassium.

The solvent used in the anionic copolymerization reaction is benzene, toluene, tetrahydrofuran, ether, isopropyl ether, ethylene glycol, n-propyl ether, hexane, cyclohexane, heptane, n-heptane, ethyl acetate, propylene glycol methyl ether , one or more of propylene glycol ethyl ether and propylene glycol methyl ether acetate.

The deprotection reaction refers to eliminating the protecting group R ₂ to make it H to obtain the PHS resin; the reagent used in the deprotection reaction is hydrobromic acid or hydrochloric acid.

In a third aspect, the present invention also provides a photoresist, including a film-forming resin; the film-forming resin includes the above-mentioned PHS resin. Preferably, the photoresist is 248nm photoresist.

Compared with the prior art, the beneficial effects obtained by the present invention are as follows:

The present invention selects the copolymerization of monomer A and monomer B to prepare PHS resin, not only utilizes monomer A with high thermal stability to significantly reduce the optical density (<0.2/μm) of the polymer resin, but also realizes anionic polymerization, thereby significantly reducing the molecular weight distribution (≤1.2), a new type of PHS resin with excellent light transmittance and narrow molecular weight distribution can be obtained.

At the same time, according to actual processing needs, by introducing monomers C and D with different properties, the molecular weight is between 1,000-100,000 and the solid content is between 5%-60%, so as to meet different usage requirements.

Detailed ways

The experimental methods used in the following examples are conventional methods unless otherwise specified.

The materials and reagents used in the following examples can be obtained from commercial sources unless otherwise specified.

Example 1

This example provides a polymer resin synthesized from vinylcyclohexane monomer A as a raw material, which is used to verify the very low optical density of vinylcyclohexane monomer A.

Concrete synthetic steps are as follows:

Under a nitrogen atmosphere, add 30 g (0.2662 mol) of vinylcyclohexane to a 270 g tetrahydrofuran (THF) solvent at -78 ° C, stir for 20 minutes, then add 4.2 ml (5 mmol) of the initiator n-butyl lithium solution, and Stir at -78°C for 30 minutes;

Next, 30 g of methanol was added to the obtained reaction mixture to quench the reaction, and then a precipitation operation was performed with a methanol solvent, which was taken out by filtration and dried in the air.

The obtained vinyl cyclohexane polymer was subjected to GPC measurement and optical density test, and the obtained results are shown in Table 1.

Example 2

This embodiment provides a target product PHS resin and its synthesis method.

Synthetic monomers: monomer A is vinylcyclohexane (k=0, R ₁ =H), monomer B is 4-methoxystyrene (R ₂ =methyl);

In the PHS resin, the ratio of the degree of polymerization is m:n=5:5.

Concrete synthetic steps are as follows:

Anionic copolymerization: under nitrogen atmosphere, add 14.7g (0.1331mol) of vinylcyclohexane and 17.9g (0.1331mol) of 4-methoxystyrene to -78°C 294g tetrahydrofuran (THF) solvent, Stir for 20 minutes, then add 4.2ml (5mmol) of n-butyllithium solution, and stir at -78°C for 30 minutes;

Next, 30 g of methanol was added to the obtained reaction mixture to quench the reaction, and then a precipitation operation was performed with a methanol solvent, which was taken out by filtration and dried in the air.

Deprotection: Dissolve the resin powder in 200g mixed solvent of toluene and ethanol at 1.6:1, add concentrated hydrochloric acid 95mmol and pure water 3.05g, stir at 90°C for 3 hours, after cooling to room temperature, add triethylamine (100mmol ), after stirring for 10 minutes, acetic acid (100 mmol) was added and concentrated. Then, the organic phase containing the resin was concentrated with ethyl acetate and pure water, and the resin solid was obtained after drying under reduced pressure.

The obtained PHS resin was subjected to GPC measurement and optical density test, and the obtained results are shown in Table 1.

Example 3

This embodiment provides a target product PHS resin and its synthesis method.

Synthetic monomers: monomer A is vinylcyclohexane (k=0, R ₁ =H), monomer B is 4-methoxystyrene (R2=methyl);

In the PHS resin, the ratio of the degree of polymerization is m:n=2:8.

Concrete synthetic steps are as follows:

Anionic copolymerization: under nitrogen atmosphere, add 5.9g (0.0532mol) of vinylcyclohexane and 28.6g (0.2130mol) of 4-methoxystyrene to -78°C 310g tetrahydrofuran (THF) solvent, Stir for 20 minutes, then add 4.2ml (5mmol) of n-butyllithium solution, and stir at -78°C for 30 minutes;

Next, 30 g of methanol was added to the obtained reaction mixture to quench the reaction, and then a precipitation operation was performed with a methanol solvent, which was taken out by filtration and dried in the air.

Deprotection: Dissolve the resin powder in 200g mixed solvent of toluene and ethanol at 1.6:1, add concentrated hydrochloric acid 95mmol and pure water 3.05g, stir at 90°C for 3 hours, after cooling to room temperature, add triethylamine (100mmol ), after stirring for 10 minutes, acetic acid (100 mmol) was added and concentrated. Then, the organic phase containing the resin was concentrated with ethyl acetate and pure water, and the resin solid was obtained after drying under reduced pressure.

The obtained PHS resin was subjected to GPC measurement and optical density test, and the obtained results are shown in Table 1.

Example 4

This embodiment provides a target product PHS resin and its synthesis method.

Synthetic monomers: monomer A is vinylcyclohexane (k=0, R ₁ =H), monomer B is 4-methoxystyrene (R2=methyl);

In the PHS resin, the ratio of the degree of polymerization is m:n:p=2:6:2.

Concrete synthetic steps are as follows:

Anionic copolymerization: under nitrogen atmosphere, add 5.9g (0.0532mol) of vinylcyclohexane, 21.5g (0.1597mol) of 4-methoxystyrene, 5.6g (0.0532mol) of styrene, stirred for 20 minutes, then added 4.2ml (5mmol) n-butyllithium solution, stirred at -78°C for 30 minutes;

Next, 30 g of methanol was added to the obtained reaction mixture to quench the reaction, and then a precipitation operation was performed with a methanol solvent, which was taken out by filtration and dried in the air.

Deprotection: Dissolve the resin powder in 200g mixed solvent of toluene and ethanol at 1.6:1, add concentrated hydrochloric acid 95mmol and pure water 3.05g, stir at 90°C for 3 hours, after cooling to room temperature, add triethylamine (100mmol ), after stirring for 10 minutes, acetic acid (100 mmol) was added and concentrated. Then, the organic phase containing the resin was concentrated with ethyl acetate and pure water, and the resin solid was obtained after drying under reduced pressure.

The obtained PHS resin was subjected to GPC measurement and optical density test, and the obtained results are shown in Table 1.

Example 5

This embodiment provides a target product PHS resin and its synthesis method.

Synthetic monomers: monomer A is vinylcyclohexane (k=0, R ₁ =H), monomer B is tert-butoxystyrene (R ₂ =tert-butyl), monomer C is styrene, Monomer D is tert-butyl methacrylate (R ₃ =tert-butyl);

In the PHS resin, the ratio of the degree of polymerization is m:n:p:q=2:4:2:2.

Concrete synthetic steps are as follows:

Anionic polymerization: under nitrogen atmosphere, add 5.9g (0.0533mol) of vinyl cyclohexane, 5.6g of styrene (0.0533mol), 18.8g (0.1066mol) ) of tert-butoxystyrene and stirred for 20 minutes, then added 4.2ml (5mmol) of n-butyllithium [initiator] solution, and stirred at -78°C for 30 minutes;

Continue to add 3.79% lithium chloride initiator/tetrahydrofuran solution 11.1g (11.3mmol) in the solution, add tert-butyl methacrylate 7.7g (0.0533mol) and di-n-butylzinc 1ml (1mmol) in the reaction solution ) in tetrahydrofuran (20g) solution, reacted for 30 minutes;

Then, 30 g of methanol was added to the resulting reaction mixture to quench the reaction, and the precipitation was performed with methanol solvent, filtered, washed three times with deionized water, and then taken out and dried in the air.

Deprotection: Dissolve the resin powder in 200g mixed solvent of toluene and ethanol at 1.6:1, add concentrated hydrochloric acid 60mmol and pure water 3.05g, stir at 90°C for 3 hours, after cooling to room temperature, add triethylamine (70mmol ), after stirring for 10 minutes, acetic acid (70 mmol) was added and concentrated. Then, the organic phase containing the resin was concentrated with ethyl acetate and pure water, and the resin solid was obtained after drying under reduced pressure.

The obtained PHS resin was subjected to GPC measurement and optical density test, and the obtained results are shown in Table 1.

Example 6

This embodiment provides a target product PHS resin and its synthesis method.

The difference from Example 2 is that the replacement monomer A is specifically 4-propylvinylcyclohexane, R ₁ =propyl, k=0.

Comparative example 1

This comparative example provides a polymeric resin synthesized using only styrene as a raw material.

Synthetic monomer: styrene;

Concrete synthetic steps are as follows:

Under nitrogen atmosphere, add 27.8g (0.2662mol) of styrene to -78°C 450g tetrahydrofuran (THF) solvent, stir for 20 minutes, then add 4.2ml (5mmol) n-butyllithium solution, at -78°C Stir for 30 minutes;

Then, 30 g of methanol was added to the resulting reaction mixture to quench the reaction, and the precipitation was performed with methanol solvent, filtered, washed three times with deionized water, and then taken out and dried in the air.

The obtained polymer was subjected to GPC measurement and optical density test, and the obtained results are shown in Table 1.

Comparative example 2

This comparative example provides a PHS resin and a synthesis method thereof.

Synthetic monomers: 4-methoxystyrene, styrene;

Concrete synthetic steps are as follows:

Under a nitrogen atmosphere, add 17.9 g (0.1331 mol) of 4-methoxystyrene and 13.9 g (0.1331 mol) of styrene to -78 ° C 450 g tetrahydrofuran (THF) solvent, stir for 20 minutes, and then add 4.2ml (5mmol) n-butyllithium solution, stirred at -78°C for 30 minutes, then quenched by adding 30g of methanol to the resulting reaction mixture to stop the reaction, then used methanol solvent for precipitation operation, filtered out and dried in the air .

Dissolve the resin powder in 200 g of a mixed solvent of toluene and ethanol at a ratio of 1.6:1, add 100 mmol of concentrated hydrochloric acid and 3.05 g of pure water, stir at 90°C for 3 hours, cool to room temperature, add triethylamine (110 mmol), and stir After 10 minutes, acetic acid (110 mmol) was added and concentrated. Then, the organic phase containing the resin was concentrated with ethyl acetate and pure water, and the resin solid was obtained after drying under reduced pressure.

The obtained polymer was subjected to GPC measurement and optical density test, and the obtained results are shown in Table 1.

Comparative example 3

This comparative example provides a polymeric resin synthesized only by using tert-butoxystyrene as a monomer raw material.

Synthetic monomer: tert-butoxystyrene;

Concrete synthetic steps are as follows:

Under nitrogen atmosphere, add 47.0 g of tert-butoxystyrene to 500 g of tetrahydrofuran (THF) solvent at -78 °C, stir for 20 minutes, then add 4.2 g (5 mmol) of n-butyllithium solution, at -78 °C Stir for 30 minutes;

Next, 30 g of methanol was added to the obtained reaction mixture to quench the reaction, and then a methanol solvent was used for precipitation operation, which was taken out by filtration and dried in the air.

Dissolve the resin powder in 200 g of a mixed solvent of toluene and ethanol at a ratio of 1.6:1, add 190 mmol of concentrated hydrochloric acid and 3.05 g of pure water, stir at 90°C for 3 hours, cool to room temperature, add triethylamine (200 mmol), and stir After 10 minutes, acetic acid (200 mmol) was added and concentrated. Then, the organic phase containing the resin was concentrated with ethyl acetate and pure water, and the resin solid was obtained after drying under reduced pressure.

The obtained polymer was subjected to GPC measurement, and the ratio of the input material to the obtained product was calculated, and the obtained results are shown in Table 1.

Comparative example 4

This comparative example provides a target product PHS resin and its synthesis method.

Synthetic monomers: monomer A is vinylcyclohexane (k=0, R ₁ =H), monomer B is 4-methoxystyrene (R2=methyl);

In the PHS resin, the ratio of the degree of polymerization is m:n=1:9.

Concrete synthetic steps are as follows:

Anionic copolymerization: under a nitrogen atmosphere, add 3.0 g (0.0266 mol) of vinylcyclohexane and 32.2 g (0.2396 mol) of 4-methoxystyrene to -78°C 317 g tetrahydrofuran (THF) solvent, Stir for 20 minutes, then add 4.2ml (5mmol) of n-butyllithium solution, and stir at -78°C for 30 minutes;

Next, 30 g of methanol was added to the obtained reaction mixture to quench the reaction, and then a precipitation operation was performed with a methanol solvent, which was taken out by filtration and dried in the air.

Deprotection: Dissolve the resin powder in 200g mixed solvent of toluene and ethanol at 1.6:1, add concentrated hydrochloric acid 95mmol and pure water 3.05g, stir at 90°C for 3 hours, after cooling to room temperature, add triethylamine (100mmol ), after stirring for 10 minutes, acetic acid (100 mmol) was added and concentrated. Then, the organic phase containing the resin was concentrated with ethyl acetate and pure water, and the resin solid was obtained after drying under reduced pressure.

The obtained polymer was subjected to GPC measurement and optical density test, and the obtained results are shown in Table 1.

Comparative example 5

This comparative example provides a target product PHS resin and its synthesis method.

Synthetic monomers: monomer A is vinylcyclohexane (k=0, R ₁ =H), monomer B is 4-methoxystyrene (R2=methyl), monomer C styrene;

In the PHS resin, the ratio of the degree of polymerization is m:n:p=2:5:3 (the degree of polymerization of monomer C styrene exceeds 20%).

Concrete synthetic steps are as follows:

Anionic copolymerization: under nitrogen atmosphere, add 5.9g (0.0532mol) of vinylcyclohexane, 17.9g (0.1331mol) of 4-methoxystyrene, 8.4g (0.0799mol) of styrene, stirred for 20 minutes, then added 4.2ml (5mmol) of n-butyllithium solution, stirred at -78°C for 30 minutes;

Next, 30 g of methanol was added to the obtained reaction mixture to quench the reaction, and then a precipitation operation was performed with a methanol solvent, which was taken out by filtration and dried in the air.

Deprotection: Dissolve the resin powder in 200g mixed solvent of toluene and ethanol at 1.6:1, add concentrated hydrochloric acid 95mmol and pure water 3.05g, stir at 90°C for 3 hours, after cooling to room temperature, add triethylamine (100mmol ), after stirring for 10 minutes, acetic acid (100 mmol) was added and concentrated. Then, the organic phase containing the resin was concentrated with ethyl acetate and pure water, and the resin solid was obtained after drying under reduced pressure.

The obtained polymer was subjected to GPC measurement and optical density test, and the obtained results are shown in Table 1.

Effect verification:

The polymer resins obtained in Examples 1-6 and Comparative Examples 1-5 were subjected to performance tests.

The test method is as follows:

Molecular weight: The weight-average molecular weight Mw, number-average molecular weight Mn, and dispersity PDI of the polymer are all measured by gel permeation chromatography. Specifically, the GPC device can be measured using Alliance E2695 from Waters Co., Ltd., and tetrahydrofuran is used as the measurement solvent.

Optical density (OD value): The UV spectrophotometer model of Agilent manufacturer Cary4000 is used for testing. The prepared solution is N,N-dimethylformamide, and the prepared concentration is 100ppm. The test formula is as follows:

D=LgO=Lg(1/T)

In the formula, D is the optical density, O is the opacity, and T is the light transmittance.

Taper angle (Tapper): Tested with an electron microscope. The angle is the inclination angle between the bottom of the resin and the substrate after exposure and etching. The closer the angle is to 90 degrees, the higher the sensitivity of the surface resin and the lower the residual film rate.

Each embodiment of table 1 and comparative example gained polymeric resin performance table

Draw the following conclusions through the above test results:

(1) Through the test results of Examples 2-6, it can be seen that the PHS resin obtained by the copolymerization of monomer A and monomer B, and the PHS resin obtained by introducing other monomers based on the copolymerization of monomer A and monomer B are all It has a very low optical density, can significantly improve the sensitivity and resolution of the photoresist, and solves the problems that the existing photoresist has low sensitivity, high residual film rate, and cannot meet the processing needs.

At the same time, the obtained PHS resin also has a narrow molecular weight distribution (PDI is controlled within 1.2), which can meet the performance requirements of the 248nm photoresist on the film-forming resin.

(2) By comparing the test results of Example 1, Example 4, Comparative Example 1, and Comparative Example 2, it can be seen that the optical density of the vinylcyclohexane polymer obtained in Example 1 is only 0.11/μm, which is far lower than that of Comparative Example 1. The optical density of the styrene polymer polymer in Comparative Example 2 shows that the vinyl cyclohexane polymer has excellent light transmittance.

(3) By comparing the test results of Example 2 and Comparative Example 3, it can be seen that the introduction of monomer A can significantly reduce the optical density of the PHS resin, thereby significantly reducing the exposure residual film rate of the photoresist.

(4) By comparing the test results of Examples 1-3 and Comparative Example 4, it can be seen that by reasonably controlling the ratio of m/n, a PHS resin with better performance can be obtained.

(5) By comparing the test results of Examples 1-3 and Comparative Example 5, it can be seen that although the degree of polymerization of monomer A is controlled to be 20%, the degree of polymerization of monomer C styrene exceeds 20%, and the optical density of the resulting resin is relatively high. Large, indicating that styrene has a negative effect on the reduction of the optical density of the resin, so the degree of polymerization of monomer C styrene must be strictly controlled.

The results show that the PHS resin prepared in Example 1 is used as the film-forming matrix, and the photoresist obtained by mixing with conventional additives has higher resolution and optical sensitivity, which effectively solves the existing photoresist sensitivity. The problem of low exposure and high residual film rate of exposure; and the obtained photoresist has good stability; thus meeting the higher processing requirements of the integrated circuit industry.

Although the present invention has been described in detail with general descriptions and specific embodiments above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the protection scope of the present invention.

Claims (10)

1. A kind of PHS resin, comprises the general structural formula shown in formula (I):

In the formula: m, n, p, and q represent the degree of polymerization of repeating unit A, repeating unit B, repeating unit C, and repeating unit D, respectively, where m≥1, n≥1, p≥0 and p/(m+n+p+ q)≤20%, q≥0; R ₁ represents H, C1-C3 alkyl, C1-C3 alkoxy or C3-C10 cycloalkyl; R ₃ represents methyl, ethyl, tert-butyl,

k represents the number of substituents R ₁ , and is a number between 0 and 5. 2. The PHS resin according to claim 1, characterized in that: in formula (I), the ratio of m:(n+p+q)≥1/4. 3. The PHS resin according to claim 1 or 2, characterized in that: the weight average molecular weight of the PHS resin is between 1000-100000, and the PDI≤1.2. 4. the synthetic method of the arbitrary described PHS resin of claim 1-3, comprises the steps: Monomer A

Monomer B/>

Monomer C/>

and/or monomer D/>

Carry out anionic copolymerization reaction as raw material, then carry out deprotection reaction to _R substituent, obtain the PHS resin described in any one of claims 1-3; The definitions of R ₁ , R ₃ , and k are the same as in formula (I); R ₂ represents one or more of methyl, ethyl, tert-butyl, propyl, isopropyl, acetoxy and propionyloxy. 5. The synthetic method according to claim 4, characterized in that: the anionic copolymerization reaction is carried out under the environment of nitrogen circulation. 6. The synthesis method according to claim 4, characterized in that: the temperature of the anionic copolymerization reaction is -75-80°C. 7. synthetic method according to claim 4, is characterized in that: the initiator that described anionic copolymerization adopts is propyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, lithium chloride, naphthalene One or more of sodium, metallic sodium and metallic potassium. 8. synthetic method according to claim 4, is characterized in that: the solvent that described anion copolymerization adopts is benzene, toluene, THF, ether, isopropyl ether, diethyl ether, n-propyl ether, hexane, cyclohexane One or more of alkane, heptane, n-heptane, ethyl acetate, propylene glycol methyl ether, propylene glycol ethyl ether and propylene glycol methyl ether acetate. 9. synthetic method according to claim 4, is characterized in that: the reagent that described deprotection reaction adopts is hydrobromic acid or hydrochloric acid. 10. A photoresist, comprising a film-forming resin; the film-forming resin comprises the PHS resin according to any one of claims 1-3, and its optical density is ≤0.2/μm.