Acrylic resin, photoresist and preparation method and application thereof

Abstract

The invention discloses an acrylic resin, a photoresist, and a preparation method and application thereof, and belongs to the field of semiconductor technology. The structural formula of the acrylic resin is as follows: wherein n=12-20, and * represents a connection point. The specific fluorine-containing group in the acrylic resin can effectively resist the corrosion of hydrofluoric acid, nitric acid and / or glacial acetic acid, and has a strong resistance to etching solution; the epoxy group can effectively improve the toughness of the photoresist. The photoresist containing the acrylic resin has at least the following advantages: the exposed pattern is insoluble in the developer, the non-exposed area is soluble in the alkaline liquid, and the rinse liquid is pure water. The developer and the rinse liquid are inexpensive compared to the organic system, and are also environmentally friendly, and the post-processing cost is relatively simple. The corresponding preparation method is simple and easy to operate.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to an acrylic resin, a photoresist, and a preparation method and application thereof. Background Art

[0002] Gpp is the abbreviation of Glassivation (glassification) passivation (passivation) parts (components) or parts of anapparats (devices). It is a general term for glass passivation devices. It refers to all active devices that introduce or contain junction film protection process means.

[0003] The important process of GPP technology is to coat the photoresist on the silicon wafer substrate, bake, expose, develop and post-bake, and then put it into the etching solution of hydrofluoric acid system to etch the silicon more than 50μm to form the required pattern.

[0004] Currently, photoresist systems are divided into phenolic, cyclized rubber, acrylic and polyimide systems. After market research and continuous testing by manufacturers, it is found that the current cyclized rubber system photoresist can meet the etching requirements of hydrofluoric acid etching liquid.

[0005] The chemical reaction of hydrofluoric acid etching silicon is: Si+4HF=SiF4↑+2H2↑. Since hydrofluoric acid generates a large amount of heat during etching, the photoresist surface is easy to fall off, and it cannot protect the silicon of the substrate, which is easy to cause corrosion. Therefore, photoresists of other systems cannot be used with hydrofluoric acid system etching solutions.

[0006] However, the common negative photoresist of the cyclized rubber system is not water-soluble, and the required developer is an organic developer, and the addition of an organic rinse solution causes great pollution to the environment.

[0007] In view of this, the present invention is proposed. Summary of the invention

[0008] One of the objects of the present invention is to provide an acrylic resin which can make the photoresist at least resistant to etching by a hydrofluoric acid system.

[0009] A second object of the present invention is to provide a method for preparing the acrylic resin.

[0010] The third object of the present invention is to provide a photoresist whose raw materials contain the above-mentioned acrylic resin.

[0011] A fourth object of the present invention is to provide a method for preparing the above-mentioned photoresist.

[0012] A fifth object of the present invention is to provide an application of the above-mentioned photoresist.

[0013] This application can be implemented as follows:

[0014] In a first aspect, the present application provides an acrylic resin, the structural formula of which is as follows:

[0015] Where n=12-20, * represents the connection point.

[0016] In an optional embodiment, the molecular weight of the acrylic resin is 8000-12000, and the index of the distribution width is 1-3;

[0017] And / or, the viscosity of the acrylic resin is 700-1200 mPa·s.

[0018] In a second aspect, the present application provides a method for preparing an acrylic resin as described in any of the aforementioned embodiments, comprising the following steps: preparing an acrylic resin according to the structural formula.

[0019] In an optional embodiment, the preparation of the acrylic resin includes: synthesizing the preparation raw materials in a first solvent environment in the presence of a catalyst.

[0020] In an optional embodiment, the catalyst is AIBM or BOP, and / or the first solvent is at least one of propylene glycol methyl ether acetate and diethylene glycol diethyl ether.

[0021] In an optional embodiment, the amount of the catalyst used is 0.045-0.1% of the raw material in the preparation, based on molar amount.

[0022] In an optional embodiment, the mass of the first solvent accounts for 60-70% of the total mass of the preparation raw materials, the catalyst and the first solvent.

[0023] In an alternative embodiment, the synthesis is carried out at 80-85° C. for 7-8 h.

[0024] In an optional embodiment, the preparation method further comprises: placing the synthesized product in water, collecting the precipitate, and drying it.

[0025] In an optional embodiment, the raw materials for preparing the acrylic resin include any one of isoprene and polybutadiene, as well as acrylic acid, methacrylic acid, hexafluoroisopropyl methacrylate and glycidyl methacrylate.

[0026] In an optional embodiment, the molar ratio of any one of isoprene and polybutadiene to acrylic acid, methacrylic acid, hexafluoroisopropyl methacrylate and glycidyl methacrylate is 1-1.2:1:0.9-1.1:0.9-1.1:1-1.2.

[0027] In a third aspect, the present application provides a photoresist, the composition of which includes the acrylic resin of any one of the aforementioned embodiments.

[0028] In an optional embodiment, the viscosity of the photoresist is 450-550 mPa·s.

[0029] In an optional embodiment, the components of the photoresist further include at least one of an initiator, a monomer, a cross-linking agent, a leveling agent and a second solvent.

[0030] In an optional embodiment, the composition of the photoresist includes 100 g of acrylic resin, 10-15 g of initiator, 0.5-1 g of monomer, 35-50 g of cross-linking agent, 0.4-0.5 g of leveling agent and 250-350 g of second solvent.

[0031] In an optional embodiment, the initiator includes at least one of photoinitiator 184 and photoinitiator 907;

[0032] and / or, the monomer is a thiol;

[0033] and / or, the crosslinking agent comprises at least one of ethylene glycol dimethacrylate and ditrimethylolpropane triacrylate;

[0034] And / or, the leveling agent includes Digo, preferably 4100;

[0035] And / or, the second solvent includes at least one of propylene glycol methyl ether acetate and diethylene glycol diethyl ether.

[0036] In an optional embodiment, the crosslinking agent consists of ethylene glycol dimethacrylate and ditrimethylolpropane triacrylate in a mass ratio of 15:25;

[0037] And / or, the second solvent consists of propylene glycol methyl ether acetate and diethylene glycol diethyl ether in a mass ratio of 200:100.

[0038] In a fourth aspect, the present application provides a method for preparing a photoresist as described in any of the aforementioned embodiments, comprising the following steps: mixing various raw materials for preparing the photoresist.

[0039] In a fifth aspect, the present application provides a photoresist as described in any of the aforementioned embodiments for coating on a surface of a silicon substrate to be etched.

[0040] In an optional embodiment, the etching of the silicon substrate is performed in an etching solution containing at least one of hydrofluoric acid, nitric acid and glacial acetic acid.

[0041] The beneficial effects of this application include:

[0042] The acrylic resin provided in the present application has a specific fluorine-containing group, which can effectively resist the corrosion of hydrofluoric acid, nitric acid and / or glacial acetic acid, and has a strong resistance to etching liquid; the epoxy group of the acrylic resin can effectively improve the toughness of the photoresist. The photoresist containing the above acrylic resin has at least the following advantages: the exposed pattern is insoluble in the developer, the non-exposed area is soluble in the alkaline liquid, and the rinse liquid is pure water. The developer and the rinse liquid are inexpensive compared to the organic system, and are environmentally friendly, and the post-processing cost is relatively simple. The corresponding preparation method is simple and easy to operate. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0044] The acrylic resin, photoresist, and preparation method and application thereof provided in this application are described in detail below.

[0045] The present application proposes an acrylic resin, the structural formula of which is as follows:

[0046] Where n=12-20, * represents the connection point.

[0047] For reference, n may be 12, 13, 14, 15, 16, 17, 18, 19 or 20, for example.

[0048] The raw materials for preparing the acrylic resin include any one of isoprene and polybutadiene, as well as acrylic acid, methacrylic acid, hexafluoroisopropyl methacrylate and glycidyl methacrylate.

[0049] That is, isoprene and polybutadiene can be used alternatively.

[0050] Among them, hexafluoroisopropyl methacrylate makes the acrylic resin have fluorine-containing groups, which can resist the corrosion of hydrofluoric acid; glycidyl methacrylate makes the acrylic resin have epoxy groups, which can improve the toughness of the photoresist.

[0051] It should be noted that any fluorine-containing group in the acrylic resin can make the corresponding photoresist resistant to etching by the hydrofluoric acid system, and not any fluorine-containing group can obtain an acrylic resin with the specific molecular structure of the present application. Only acrylic resins containing the molecular structure of the specific fluorine-containing group proposed in the present application can effectively solve the technical problem of the present application.

[0052] In some preferred embodiments, the molar ratio of any one of isoprene and polybutadiene to acrylic acid, methacrylic acid, hexafluoroisopropyl methacrylate and glycidyl methacrylate is 1-1.2:1:0.9-1.1:0.9-1.1:1-1.2.

[0053] That is, the molar ratio of isoprene or polybutadiene to acrylic acid may be 1:1, 1.05:1, 1.1:1, 1.15:1 or 1.2:1, or any other value within the range of 1-1.2:1.

[0054] The molar ratio of methacrylic acid to acrylic acid may be 0.9:1, 0.95:1, 1:1, 1.05:1 or 1.1:1, or any other value within the range of 0.9-1.1:1.

[0055] The molar ratio of hexafluoroisopropyl methacrylate to acrylic acid may be 0.9:1, 0.95:1, 1:1, 1.05:1 or 1.1:1, or any other value within the range of 0.9-1.1:1.

[0056] The molar ratio of glycidyl methacrylate to acrylic acid may be 1:1, 1.05:1, 1.1:1, 1.15:1 or 1.2:1, or any other value within the range of 1-1.2:1.

[0057] The acrylic resin provided in the present application has a molecular weight of 8000-12000, a distribution width index of 1-3, and a viscosity of 700-1200 mPa·s.

[0058] The index of the distribution width is the weight average molecular weight M w and number average molecular weight M n ratio.

[0059] The acrylic resin having the above molecular weight, distribution and viscosity can make the corresponding photoresist have better hydrofluoric acid resistance.

[0060] Correspondingly, the present application also provides a method for preparing the above acrylic resin, comprising the following steps: preparing acrylic resin according to the structural formula.

[0061] For reference, the raw materials can be synthesized in the presence of a catalyst in a first solvent environment.

[0062] The catalyst may be, for example, AIBM or BOP, and the first solvent may be, for example, at least one of propylene glycol methyl ether acetate and diethylene glycol diethyl ether.

[0063] In terms of molar amount, the amount of the catalyst used can be 0.045-0.1% of the raw material, such as 0.045%, 0.05%, 0.055%, 0.06%, 0.065%, 0.07%, 0.075%, 0.08%, 0.085%, 0.09%, 0.095% or 0.1%, etc., or it can be any other value within the range of 0.045-0.1%.

[0064] The mass of the first solvent accounts for 60-70% of the total mass of the raw materials, catalyst and the first solvent, such as 60%, 62%, 65%, 68% or 70%, etc., and can also be any other value within the range of 60-70%.

[0065] The above synthesis process can be carried out at 80-85°C (such as 80°C, 81°C, 82°C, 83°C, 84°C or 85°C, etc.) for 7-8h (such as 7h, 7.2h, 7.5h, 7.8h or 8h, etc.).

[0066] Furthermore, after the synthesis, the synthesized product can be placed in water, and the precipitate can be collected and dried.

[0067] Specifically, the synthesized product is directly introduced into water, the precipitated resin is washed out (the monomers not involved in the reaction are dissolved in water), and then dried in an oven under reduced pressure (eg, 80° C.) to obtain the desired resin.

[0068] In addition, the present application also provides a photoresist, the composition of which includes the above-mentioned acrylic resin.

[0069] Preferably, the viscosity of the photoresist is 450-550 mPa·s (eg, 500 mPa·s).

[0070] At the above viscosity, the film can have a suitable thickness.

[0071] The components of the photoresist further include at least one of an initiator, a monomer, a cross-linking agent, a leveling agent and a second solvent.

[0072] In some embodiments, the photoresist is obtained by reacting the acrylic resin, initiator, thiol, crosslinking agent, leveling agent and second solvent.

[0073] For reference, the components of the above-mentioned photoresist include 100g of acrylic resin, 10-15g (such as 10g, 11g, 12g, 13g, 14g or 15g, etc.) of initiator, 0.5-1g (such as 0.5g, 0.6g, 0.7g, 0.8g, 0.9g or 1g, etc.) of monomer, 35-50g (such as 35g, 38g, 40g, 42g, 45g, 48g or 50g, etc.) of cross-linking agent, 0.4-0.5g (such as 0.4g, 0.42g, 0.45g, 0.48g or 0.5g, etc.) of leveling agent and 250-350g (such as 250g, 280g, 300g, 320g or 350g, etc.) of second solvent.

[0074] The initiator includes at least one of the photoinitiator 184 and the photoinitiator 907 .

[0075] The monomer is thiol.

[0076] The crosslinking agent includes at least one of ethylene glycol dimethacrylate and ditrimethylolpropane triacrylate. In some preferred embodiments, the crosslinking agent is composed of ethylene glycol dimethacrylate and ditrimethylolpropane triacrylate, and the mass ratio of the two can be, for example, 15:25 or 20:25.

[0077] The leveling agent includes Digo, such as Digo 4100.

[0078] The second solvent includes at least one of propylene glycol methyl ether acetate and diethylene glycol diethyl ether. In some preferred embodiments, the second solvent consists of propylene glycol methyl ether acetate and diethylene glycol diethyl ether, and the mass ratio of the two can be, for example, 200:100.

[0079] As mentioned above, the feed ratio and purity of acrylic resin are key factors that determine the photoresist's resistance to hydrofluoric acid (after polymerization, acrylic resin has a certain molecular weight and has a cross-linking effect. If it exists as a monomer, no cross-linking will be formed, resulting in insufficient cross-linking density after the photoresist is exposed, which is insufficient to resist hydrofluoric acid corrosion. The feed ratio should be moderate. If some monomers are fed too much, their reaction proportion will become higher and the structure will change. The remaining monomers will not react, resulting in changes in their subsequent molecular weight and changes in their chemical resistance); the ratio of initiator to cross-linker affects the cross-linking condition of the photoresist after exposure.

[0080] Specifically, in the above-mentioned system for preparing photoresist, acrylic resin itself has a certain solubility, and the larger its molecular weight and the fluorine functional group it contains, the stronger its resistance to etching solution (it should be emphasized that if the molecular weight continues to expand beyond a certain range, it will cause the pattern to change after exposure, that is, the pattern morphology will change after exposure. For example, the mask is 10μm, and the normal structure exposure is a 10μm photoresist pattern, but after the molecular weight is too large, the pattern will become more than 12μm). The cross-linking agent helps to increase the dissolution rate of the unexposed area of ​​the photoresist; after exposure, the initiator absorbs the light source, and the formed free radicals cross-link with the double bond groups of the resin and the cross-linking agent to form an insoluble and dense network structure. The cross-linking agent is embedded in the resin system, and the new structure formed is not alkali soluble (insoluble in alkaline solution). In this way, in the developer, the unexposed area is alkali soluble, and the exposed area is not alkali soluble. The thicker the film thickness, the higher the contrast of the pattern, and the steeper the angle formed.

[0081] Correspondingly, the present application also provides a method for preparing the above-mentioned photoresist, comprising the following steps: mixing various raw materials for preparing the photoresist.

[0082] Specifically, the above raw materials can be stirred and mixed according to proportion, filtered, and adjusted to a suitable viscosity.

[0083] In addition, the present application also provides applications of the above-mentioned photoresist, for example, for coating on the surface of a silicon substrate to be etched.

[0084] In some prominent embodiments, the etching of the silicon substrate is performed in an etching solution containing at least one of hydrofluoric acid, nitric acid and glacial acetic acid, and in particular in an etching solution containing hydrofluoric acid.

[0085] For reference, the silicon substrate coated with the above-mentioned photoresist is baked (e.g., 120°C, 5 minutes), exposed, developed (e.g., 2.38wt% TMAH solution or 0.4wt% KOH solution or 0.4wt% NaOH solution, 3 minutes), post-baked (e.g., 130°C, 3 minutes), etched in a hydrofluoric acid system, and then washed with water. The corresponding photoresist surface is normal, the surface of the photoresist is not cracked, no colloid is separated from the silicon substrate, and no corrosion occurs.

[0086] That is, the acrylic acid system photoresist provided by the present application is insoluble in developer after exposure, and the non-exposed area is soluble in alkaline liquid (which can be an organic 2.38wt% TMAH solution, or a 0.4wt% KOH solution or a 0.4wt% NaOH solution), and the rinse liquid is pure water. The developer and rinse liquid are inexpensive compared to organic systems, and are environmentally friendly, and the post-processing cost is relatively simple.

[0087] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0088] Example 1

[0089] This embodiment provides a photoresist, which is obtained by stirring and mixing the following raw materials, filtering, and adjusting the viscosity (viscosity is 500 mPa·s).

[0090] Specifically, the raw materials are as follows:

[0091] 100g of acrylic resin, 10g of initiator (photoinitiator 184), 0.5g of thiol, 15g of ethylene glycol dimethacrylate, 25g of ditrimethylolpropane triacrylate, 0.45g of leveling agent (Digo 4100), 200g of propylene glycol methyl ether acetate and 100g of diethylene glycol diethyl ether.

[0092] Among them, the structural formula of acrylic resin is as follows:

[0093]

[0094] Among them, * represents a connection point.

[0095] The acrylic resin is prepared by the following method: acrylic acid, isoprene, methacrylic acid, hexafluoroisopropyl methacrylate and glycidyl methacrylate are synthesized in a first solvent (propylene glycol methyl ether acetate) environment in the presence of a catalyst (AIBM) at a molar ratio of 1:1.1:1:1:1.1 (synthesis temperature is 85° C., synthesis time is 7.5 hours). The amount of AIBM used is 0.1% of the raw material in terms of molar amount. The mass of the first solvent accounts for 65% of the total mass of the raw material, the catalyst and the first solvent.

[0096] The synthesized product is directly introduced into water, the precipitated resin is washed out, and then dried in an oven under reduced pressure (e.g., 80° C.).

[0097] The obtained acrylic resin had a molecular weight of 9,000, a distribution of 1.63, and a viscosity of 960 mPa·s.

[0098] Example 2

[0099] The difference between this embodiment and embodiment 1 is that the composition of the photoresist is as follows:

[0100] 100g of acrylic resin, 15g of initiator (photoinitiator 184), 1g of thiol, 20g of ethylene glycol dimethacrylate, 25g of ditrimethylolpropane triacrylate, 0.45g of leveling agent (Digo 4100), 200g of propylene glycol methyl ether acetate and 100g of diethylene glycol diethyl ether.

[0101] Example 3

[0102] The acrylic resin is prepared by the following method: acrylic acid, isoprene, methacrylic acid, hexafluoroisopropyl methacrylate and glycidyl methacrylate are synthesized in a first solvent (propylene glycol methyl ether acetate) environment in the presence of a catalyst (AIBM) at a molar ratio of 1:1:0.9:0.9:1 (synthesis temperature is 80°C, synthesis time is 8h). The amount of AIBM used is 0.45% of the raw material in terms of molar amount. The mass of the first solvent accounts for 60% of the total mass of the raw material, the catalyst and the first solvent.

[0103] The acrylic resin has a molecular weight of 10,000, a distribution of 1.56, and a viscosity of 850 mPa·s.

[0104] Example 4

[0105] The acrylic resin is prepared by the following method: acrylic acid, isoprene, methacrylic acid, hexafluoroisopropyl methacrylate and glycidyl methacrylate are synthesized in a first solvent (propylene glycol methyl ether acetate) environment in the presence of a catalyst (AIBM) at a molar ratio of 1.2:1:1.1:1.1:1.2 (synthesis temperature is 82°C, synthesis time is 7h). The amount of AIBM used is 0.55% of the raw material in terms of molar amount. The mass of the first solvent accounts for 70% of the total mass of the raw material, the catalyst and the first solvent.

[0106] The acrylic resin has a molecular weight of 9200, a distribution of 1.75, and a viscosity of 1020 mPa·s.

[0107] Comparative Example 1

[0108] The difference between this comparative example and Example 1 is that the composition of the photoresist is as follows:

[0109] 100g of acrylic resin, 8g of initiator (photoinitiator 184), 0.5g of thiol, 20g of ethylene glycol dimethacrylate, 25g of ditrimethylolpropane triacrylate, 0.45g of leveling agent (Digo 4100), 200g of propylene glycol methyl ether acetate and 100g of diethylene glycol diethyl ether.

[0110] Comparative Example 2

[0111] The difference between this comparative example and Example 1 is that the composition of the photoresist is as follows:

[0112] 100g of acrylic resin, 7g of initiator (photoinitiator 184), 0.5g of thiol, 25g of ethylene glycol dimethacrylate, 30g of ditrimethylolpropane triacrylate, 0.45g of leveling agent (Digo 4100), 200g of propylene glycol methyl ether acetate and 100g of diethylene glycol diethyl ether.

[0113] Comparative Example 3

[0114] The difference between this comparative example and Example 1 is that the composition of the photoresist is as follows:

[0115] 100g of acrylic resin, 10g of initiator (photoinitiator 184), 0.5g of thiol, 30g of ethylene glycol dimethacrylate, 20g of ditrimethylolpropane triacrylate, 0.45g of leveling agent (Digo 4100), 200g of propylene glycol methyl ether acetate and 100g of diethylene glycol diethyl ether.

[0116] Comparative Example 4

[0117] The difference between this comparative example and Example 1 is that the composition of the photoresist is as follows:

[0118] 100g of acrylic resin, 10g of initiator (photoinitiator 184), 0.5g of thiol, 15g of ethylene glycol dimethacrylate, 15g of ditrimethylolpropane triacrylate, 0.45g of leveling agent (Digo 4100), 200g of propylene glycol methyl ether acetate and 100g of diethylene glycol diethyl ether.

[0119] Comparative Example 5

[0120] The difference between this comparative example and Example 1 is that the molecular weight of the acrylic resin is 5000.

[0121] Comparative Example 6

[0122] The difference between this comparative example and Example 1 is that the molecular weight of the acrylic resin is 15,000.

[0123] Comparative Example 7

[0124] The difference between this comparative example and Example 1 is that the index of the distribution width of the acrylic resin is 0.5.

[0125] Comparative Example 8

[0126] The difference between this comparative example and Example 1 is that the index of the distribution width of the acrylic resin is 3.5.

[0127] Comparative Example 9

[0128] The difference between this comparative example and Example 1 is that the viscosity of the acrylic resin is 500 mPa·s.

[0129] Comparative Example 10

[0130] The difference between this comparative example and Example 1 is that the viscosity of the acrylic resin is 1500 mPa·s.

[0131] Comparative Example 11

[0132] The difference between this comparative example and Example 1 is that the hexafluoroisopropyl methacrylate in the acrylic resin is increased by 30%, and the other components remain unchanged.

[0133] Test example

[0134] The photoresists obtained in the above Examples 1-4 and Comparative Examples 1-11 were coated on silicon wafers under the same conditions, baked (120°C, 5min), exposed, developed (2.38% TMAH, 3min), and post-baked (130°C, 3min). The film retention rate of each group was tested, and the etching structure of each group after etching was completed in the etching solution was observed. The results are shown in Table 1.

[0135] Table 1 Results

[0136]

[0137]

[0138] Among them, "NG" means that it does not meet the production process requirements. The production process needs to consider that the development time cannot be too fast or too slow, the film retention rate is greater than 90%, and there is no peeling or degumming. The glue surface is normal after corrosion and no lateral corrosion occurs.

[0139] It can be seen that the acrylic system photoresist provided in the embodiment of the present application is resistant to hydrofluoric acid etching, and can effectively maintain good adhesiveness of the adhesive surface while etching silicon patterns, without cracking, floating adhesive, and falling off. When the type, molecular weight, distribution width index, viscosity or dosage of the acrylic resin changes, the corresponding photoresist will not be able to effectively resist hydrofluoric acid etching.

[0140] In summary, the photoresist provided in the present application is resistant to etching by hydrofluoric acid, nitric acid, and glacial acetic acid etching solutions, does not cause cracking of the photoresist surface and floating of the photoresist, and can be applied to the silicon etching process in the GPP diode industry.

[0141] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An acrylic resin, characterized in that The structural formula of the acrylic resin is as follows: Where n = 12-20, * represents the connection point; The molecular weight of the acrylic resin is 8000-12000, and the index of distribution width is 1-3; The viscosity of the acrylic resin is 700-1200 mPa·s; The raw materials for preparing the acrylic resin include isoprene and acrylic acid, methacrylic acid, hexafluoroisopropyl methacrylate and glycidyl methacrylate; the molar ratio of the isoprene to the acrylic acid, the methacrylic acid, the hexafluoroisopropyl methacrylate and the glycidyl methacrylate is 1-1.2:1:0.9-1.1:0.9-1.1:1-1.

2.

2. A method for preparing an acrylic resin as claimed in claim 1, characterized in that: The following steps are involved: Prepare the acrylic resin according to the structural formula; The preparation of the acrylic resin comprises: synthesizing the raw materials for preparing the acrylic resin in a first solvent environment in the presence of a catalyst; The catalyst is AIBM or BOP, and the first solvent is at least one of propylene glycol methyl ether acetate and diethylene glycol diethyl ether; The amount of the catalyst used is 0.045-0.1% of the raw material in the preparation, based on molar amount; The mass of the first solvent accounts for 60-70% of the total mass of the preparation raw materials, the catalyst and the first solvent; The synthesis was carried out at 80-85°C for 7-8h.

3. The preparation method according to claim 2, characterized in that: Also includes: The synthesized product was placed in water, and the precipitate was collected and dried.

4. A photoresist, characterized in that: The photoresist comprises 100 g of the acrylic resin as claimed in claim 1, 10-15 g of an initiator, 0.5-1 g of a monomer, 35-50 g of a cross-linking agent, 0.4-0.5 g of a leveling agent and 250-350 g of a second solvent; the monomer is thiol.

5. The photoresist according to claim 4, characterized in that The viscosity of the photoresist is 450-550 mPa·s.

6. The photoresist according to claim 4, characterized in that The initiator includes at least one of photoinitiator 184 and photoinitiator 907; and / or, the cross-linking agent comprises at least one of ethylene glycol dimethacrylate and ditrimethylolpropane triacrylate; And / or, the leveling agent includes Digo; And / or, the second solvent includes at least one of propylene glycol methyl ether acetate and diethylene glycol diethyl ether.

7. The photoresist according to claim 6, characterized in that The crosslinking agent is composed of ethylene glycol dimethacrylate and ditrimethylolpropane triacrylate in a mass ratio of 15:25; And / or, the second solvent consists of propylene glycol methyl ether acetate and diethylene glycol diethyl ether in a mass ratio of 200:

100.

8. The method for preparing a photoresist according to any one of claims 4 to 7, characterized in that: The following steps are involved: The raw materials for preparing the photoresist are mixed.

9. The use of the photoresist according to any one of claims 4 to 7, characterized in that: The photoresist is used for coating on the surface of the silicon substrate to be etched.

10. The use according to claim 9, characterized in that: The etching of the silicon substrate is carried out in an etching solution containing at least one of hydrofluoric acid, nitric acid and glacial acetic acid.

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