Phenolic compound, preparation method and application thereof, and photoresist

Abstract

The present application provides a phenolic compound, a preparation method, an application thereof, and a photoresist, belonging to the field of photolithography technology. The phenolic compound of the present application can improve the resolution of the photoresist and at the same time make the photoresist have better photolithography performance, specifically manifested in better sensitivity, greater contrast, a morphology with a more vertical sidewall angle, and a larger process window. The photoresist comprises 10 to 30 wt% of a phenolic resin, 2 to 10 wt% of a diazonaphthoquinone sensitizer, 0.1 to 5 wt% of a leveling agent, 40 to 80 wt% of a solvent, and 0.1 to 10 wt% of a phenolic compound.

Description

Technical Field

[0001] The present application relates to the field of photolithography technology, and in particular to a phenolic compound, a preparation method and application thereof, and a photoresist. Background Art

[0002] With the vigorous development of new infrastructure such as cloud computing, the Internet of Things, 5G communications, and artificial intelligence, integrated circuits, as one of the core industries of the information industry, have also embarked on a path of rapid development.

[0003] Photoresist is a key material required for integrated circuit manufacturing. 365nm (i-line) photoresist uses phenolic resin and diazonaphthoquinone as its base resin. Through photolithography procedures such as exposure and development, the pattern of the mask is transferred and copied onto the silicon wafer. 365nm photoresist is widely used in the process of integrated circuit manufacturing ranging from hundreds of nanometers to several microns.

[0004] Photoresists are categorized as positive-tone and negative-tone based on their solubility changes before and after exposure. Positive-tone photoresists exhibit increased solubility after exposure, while negative-tone photoresists exhibit decreased solubility. Positive-tone photoresists exhibit increased solubility in exposed areas, allowing them to be washed away with an alkaline developer, leaving unexposed areas on the substrate to form a pattern. Negative-tone photoresists exhibit the opposite effect, with exposed areas remaining on the substrate to form a pattern.

[0005] In the manufacture of integrated circuits, the resolution of photoresist directly affects the precision and other performance of the photolithographic device. According to the Rayleigh equation, in the photolithography process, the resolution is inversely proportional to the wavelength. i-line photoresists generally have the problem of low resolution. Improving the resolution is an important indicator for improving the performance of i-line photoresists. Summary of the Invention

[0006] The present application provides a phenolic compound, a preparation method and application, and a photoresist, which can improve the resolution of the photoresist.

[0007] The embodiment of the present application is implemented as follows:

[0008] In the first aspect, the present application provides a phenolic compound, the structural formula of which is as follows:

[0009]

[0010] Wherein, R1 is selected from -C 1-6 Alkyl, -C 1-6 Alkyl-OH, -OC 1-6 Alkyl, -OC 1-6 Alkyl-(OH) m , -C 1-4 -(Ph) or -C 1-4 -(Ph)-(OH) m .

[0011] R2 and R3 are each independently selected from -H, -OH, -C 1-4 Alkyl, -C 1-4 Alkyl -OH or -OC 1-4 alkyl.

[0012] R4 and R5 are each independently selected from

[0013] The alkyl group is a linear, branched or cyclic alkyl group.

[0014] m is an integer from 1 to 3.

[0015] In the above technical solution, the phenolic compound of the present application can be added to the photoresist as an additive. The photoresist added with the phenolic compound has the characteristics of high resolution, fast photosensitivity and large process window.

[0016] In combination with the first aspect, in a first possible example of the first aspect of the present application, at least one of the above R4 and R5 is selected from

[0017] In combination with the first aspect, in a second possible example of the first aspect of the present application, the above R1 is selected from -C 1-4 Alkyl, -C 1-4 Alkyl -OH or -OC 1-4 Alkyl-(OH) m .

[0018] R2 is selected from -OH, -C 1-4 Alkyl or -C 1-4 Alkyl-OH.

[0019] R3 is selected from -OH, -C 1-4 Alkyl or -C 1-4 Alkyl-OH.

[0020] In a second aspect, the present application provides an example of a method for preparing the above-mentioned phenolic compound, which comprises: reacting compound A and compound B at 0-25° C. for 6-24 hours.

[0021] The chemical formula of compound A is as follows:

[0022]

[0023] The chemical formula of compound B is

[0024] In the above technical solution, the preparation method of the present application is simple and the structure of the prepared phenolic compound is stable.

[0025] In a third aspect, the present application provides an example of using the above-mentioned phenolic compounds as additives in photoresists.

[0026] In the above technical solution, the above phenolic compounds can be added to the photoresist as additives, thereby improving the resolution, photosensitivity and process window of the photoresist.

[0027] In combination with the third aspect, in a first possible example of the third aspect of the present application, the photoresist is an i-line photoresist.

[0028] Optionally, the photoresist is a diazonaphthoquinone photoresist.

[0029] In a fourth aspect, the present application provides an example of a photoresist comprising the above-mentioned phenolic compound.

[0030] In the above technical solution, the photoresist of the present application has improved resolution, increased photosensitivity and enlarged process window by adding phenolic compounds.

[0031] In combination with the fourth aspect, in a first possible example of the fourth aspect of the present application, the addition amount of the above-mentioned phenolic compound is 0.1 to 10 wt % of the photoresist.

[0032] Optionally, the added amount of the phenolic compound is 0.1 to 5 wt % of the photoresist.

[0033] Optionally, the added amount of the phenolic compound is 0.1-2 wt % of the photoresist.

[0034] In combination with the fourth aspect, in a second possible example of the fourth aspect of the present application, the above-mentioned photoresist further includes a phenolic resin, a diazonaphthoquinone photosensitizer, a leveling agent and a solvent.

[0035] In combination with the fourth aspect, in a third possible example of the fourth aspect of the present application, the above-mentioned photoresist includes 10 to 30 wt% phenolic resin, 2 to 10 wt% diazonaphthoquinone photosensitizer, 0.1 to 5 wt% leveling agent, 40 to 80 wt% solvent and 0.1 to 10 wt% phenolic compound.

[0036] In the above example, the resolution of the photoresist of the present application is ≤360 nm, the photosensitivity is ≤180 mJ, the energy window EL is ≥17%, and the focus window DOF is ≥1.6 um. DETAILED DESCRIPTION

[0037] The embodiments of the present application will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0038] The common approach to addressing low resolution in existing technologies is to adjust the two main materials: the photosensitive agent and the resin. However, due to structural variations and limited physical and chemical properties of these materials, photoresist properties such as sensitivity, heat resistance, resolution, and process window often require multiple adjustments in dosage and structure to achieve a balanced balance between resolution and sensitivity.

[0039] In order to overcome this technical defect, the phenolic compounds of the present application improve the resolution of the photoresist and at the same time make the photoresist have better lithographic performance, which is specifically manifested in better sensitivity, greater contrast, a more vertical side wall angle morphology and a larger process window.

[0040] The following is a detailed description of a phenolic compound, preparation method, application, and photoresist according to an embodiment of the present application:

[0041] The present application provides a phenolic compound, the structural formula of which is as follows:

[0042]

[0043] Wherein, R1 is selected from -C 1-6 Alkyl, -C 1-6 Alkyl-OH, -OC 1-6 Alkyl, -OC 1-6 Alkyl-(OH) m , -C 1-4 -(Ph) or -C 1-4 -(Ph)-(OH) m .

[0044] R2 and R3 are each independently selected from -H, -OH, -C 1-4 Alkyl, -C 1-4 Alkyl -OH or -OC 1-4 alkyl.

[0045] R4 and R5 are each independently selected from

[0046] Ph in R1 of the present application is a phenyl group, and the alkyl group is a straight-chain, branched-chain alkyl group or a cycloalkyl group.

[0047] The m in R1 of the present application is an integer from 1 to 3. For example, R1 can be -OC1-4 Alkyl-(OH), -OC 1-4 Alkyl-(OH)2, -OC 1-4 Alkyl-(OH)3, -C 1-4 -(Ph)-(OH), -C 1-4 -(Ph)-(OH)2 or -C 1-4 -(Ph)-(OH)3.

[0048] It should be noted that the structures of R2 and R3 of the phenolic compounds of the present application may be the same or different, and the structures of R4 and R5 may also be the same or different.

[0049] Optionally, at least one of R4 and R5 is selected from

[0050] That is, the phenolic compound of the present application is selected from any one of the following compounds:

[0051]

[0052] Optionally, R1 is selected from -C 1-4 Alkyl, -C 1-4 Alkyl -OH or -OC 1-4 Alkyl-(OH) m .

[0053] For example, the structural formula of the phenolic compound of the present application is as follows:

[0054]

[0055] Optionally, R2 and R3 are each independently selected from -H, -OH, -C 1-4 Alkyl, -C 1-4 Alkyl -OH or -OC 1-4 alkyl.

[0056] The present application also provides a method for preparing the above-mentioned phenolic compound, which comprises: reacting compound A and compound B at 0-25° C. for 6-24 hours.

[0057] The chemical formula of compound A is as follows:

[0058]

[0059] The chemical formula of compound B is

[0060] The molar ratio of compound A to compound B is 1:(1-6).

[0061] Optionally, the molar ratio of compound A to compound B is 1:(2-6)

[0062] Optionally, the molar ratio of compound A to compound B is 1:(3-5).

[0063] Optionally, the molar ratio of compound A to compound B is 1:4.

[0064] In one embodiment of the present application, the molar ratio of compound A to compound B is 1:4. In some other embodiments of the present application, the molar ratio of compound A to compound B is 1:1, 1:2, 1:3, 1:5 or 1:6.

[0065] It should be noted that compound B can be one or two. When compound B is one, the above molar ratio is the molar ratio of compound A to one compound B; when compound B is two, the above molar ratio is the molar ratio of compound B to the sum of the two compounds B.

[0066] In addition, when there are two compounds B, there may be multiple products, and the target product can be obtained later by separation methods.

[0067] First, compound A and compound B are dissolved in solvents respectively, and then reacted.

[0068] Solvents include N-methylpyrrolidone, ethanol, and propylene glycol methyl ether acetate.

[0069] It should be noted that the solvent selected in the preparation method of the phenolic compound of the present application needs to be selected according to the specific compound A and compound B.

[0070] Before the reaction, a catalyst may be added to the reaction system.

[0071] The catalyst includes 4-dimethylaminopyridine.

[0072] It should be noted that not all reactions of A and B require a catalyst. A catalyst may not be required. Whether a catalyst is required depends on the specific compounds A and B.

[0073] In one embodiment of the present application, the reaction temperature is 20° C. In some other embodiments of the present application, the reaction temperature is 0° C., 1° C., 2° C., 3° ​​C., 4° C., 5° C., 6° C., 7° C., 8° C., 9° C., 10° C., 11° C., 12° C., 13° C., 14° C., 15° C., 16° C., 17° C., 18° C., 19° C., 21° C., 22° C., 23° C., 24° C. or 25° C.

[0074] It should be noted that the reaction temperature of the present application needs to be selected according to the specific compound A and compound B.

[0075] In one embodiment of the present application, the reaction time is 18 hours. In some other embodiments of the present application, the reaction time is 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours or 24 hours.

[0076] The present application also provides a use of a phenolic compound as an additive in photoresist.

[0077] Phenolic compounds can be added to photoresists as additives to improve the resolution, photosensitivity and process window of the photoresists.

[0078] Optionally, the photoresist is i-line photoresist.

[0079] Optionally, the photoresist is a diazonaphthoquinone photoresist.

[0080] Optionally, the photoresist is a positive-type naphthoquinone diazide photoresist.

[0081] The present application also provides a photoresist comprising the above-mentioned phenolic compound.

[0082] The photoresist of the present application improves its resolution, increases its photosensitivity and enlarges its process window by adding phenolic compounds.

[0083] The added amount of the phenolic compound is 0.1 to 10 wt % of the photoresist.

[0084] Optionally, the added amount of the phenolic compound is 0.1 to 5 wt % of the photoresist.

[0085] Optionally, the added amount of the phenolic compound is 0.1-2 wt % of the photoresist.

[0086] In one embodiment of the present application, the amount of the phenolic compound added is 1 wt % of the photoresist. In other embodiments of the present application, the amount of the phenolic compound added is 0.1 wt %, 0.2 wt %, 0.5 wt %, 0.8 wt %, 1.2 wt %, 1.5 wt %, 1.8 wt %, 2 wt %, 2.5 wt %, 3 wt %, 3.5 wt %, 4 wt %, 4.5 wt % or 5 wt % of the photoresist.

[0087] Optionally, the photoresist includes a phenolic resin, a diazonaphthoquinone photosensitizer, a leveling agent, a solvent, and a phenolic compound.

[0088] Optionally, the photoresist includes 10-30 wt % of phenolic resin, 2-10 wt % of diazonaphthoquinone photosensitizer, 0.1-5 wt % of leveling agent, 40-80 wt % of solvent and 0.1-10 wt % of phenolic compound.

[0089] Optionally, the molecular weight of the phenolic resin is 4000-8000.

[0090] The general structural formula of phenolic resin is as follows:

[0091]

[0092] The ratio o / p / m of o-cresol, p-cresol and m-cresol in the phenolic resin is an arbitrary ratio.

[0093] Optionally, the diazonaphthoquinone sensitizer includes 2, 1, 4-type diazonaphthoquinone sensitizers and 2, 1, 5-type diazonaphthoquinone sensitizers, and the optional structures thereof are as follows:

[0094]

[0095] PAC-1: R = H, or

[0096] PAC-2: R = H, or

[0097] Optionally, the leveling agent includes any one or more of a silicone leveling agent, an ethylene oxide / propylene leveling agent, and a fluorinated polymethyl methacrylate leveling agent, wherein the silicone leveling agent has the following structural formula:

[0098]

[0099] Optionally, the solvent includes any one or more of propylene glycol methyl ether acetate, 2-heptanone and ethyl lactate.

[0100] The photoresist of the present application has a resolution of ≤360 nm, a photosensitivity of ≤180 mJ, an energy window EL ≥17%, and a focus window DOF ≥1.6 um.

[0101] The following is a further detailed description of a phenolic compound, preparation method, application, and photoresist of the present application in conjunction with examples.

[0102] Example 1

[0103] The present invention provides a phenolic compound and a preparation method thereof, which comprises the following steps:

[0104] 3.06 g (0.01 mol) of 1,1,1-tris(4-hydroxyphenyl)ethane and 1.22 g (0.01 mol) of 4-dimethylaminopyridine (DMAP) were dissolved in 200 ml of N-methylpyrrolidone (NMP) and placed in a round-bottom flask and stirred for 20 min until dissolved. After mixing evenly, 8.72 g (0.04 mol) of di-tert-butyl dicarbonate was added dropwise to the round-bottom flask at a low temperature (0-5 ° C). The mixture was stirred and reacted at 20 ° C for 24 h. After the reaction was completed, the excess DMAP was removed by washing three times with deionized water. The organic layer and the aqueous layer were separated, and the solvent was first rotary evaporated to obtain a crude product. Finally, ethyl acetate / petroleum ether (v / v 7 / 3) was used as the eluent for column chromatography to obtain a white powder, namely, phenolic compound A, with a yield of 78.2%.

[0105] The reaction formula of the embodiment of the present application is as follows:

[0106]

[0107] Example 2

[0108] The present invention provides a phenolic compound and a preparation method thereof, which comprises the following steps:

[0109] Take 2.56g (0.01mol) of 2,2-bis(4-hydroxy-3-phenylmethyl)propane and 1ml of 25wt% p-toluenesulfonic acid and dissolve them in 150ml of ethanol. Place them in a round-bottom flask and stir for 30min. After mixing evenly, 2.88g (0.04mol) of vinyl ethyl ether is uniformly added dropwise to the round-bottom flask at 25°C. The reaction is stirred at 25°C for 24h. After the reaction is completed, an appropriate amount of Na2HCO3 is added dropwise to the reaction system to remove the residual p-toluenesulfonic acid. After washing with water three times, the aqueous layer and the organic layer are separated. The solvent is first rotary evaporated to obtain a crude product. Finally, chloroform / petroleum ether is used as the eluent for column chromatography to obtain a yellow liquid, namely, phenolic compound B, with a yield of 71.0%.

[0110] The reaction formula of the embodiment of the present application is as follows:

[0111]

[0112] Example 3

[0113] The present invention provides a phenolic compound and a preparation method thereof, which comprises the following steps:

[0114] Take 5.36g (0.02mol) of 4,4'-dihydroxydiphenylcyclohexane and 2.44g (0.02mol) of 4-dimethylaminopyridine (DMAP) and dissolve them in 200ml of propylene glycol methyl ether acetate (PGMEA). After mixing evenly, add 4.36g (0.02mol) of di-tert-butyl dicarbonate and place them in a round-bottom flask and stir for 20min. After reacting at room temperature for 18 hours, wash off the residual DMAP with deionized water and separate the product a by column chromatography using ethyl acetate / petroleum ether as eluent. Then take 3.64g (0.01mol) of the intermediate product and 1.44g (0.02mol) of vinyl ethyl ether and add them dropwise to the round-bottom flask at a uniform speed at low temperature (0-5°C). Slowly add 1ml of the mixture dropwise to the flask. 25wt% p-toluenesulfonic acid was stirred and reacted at 20°C for 12h. After the reaction was completed, an appropriate amount of Na2HCO3 was added dropwise to the reaction system to remove the residual p-toluenesulfonic acid. The mixture was washed with water three times and extracted with dichloromethane three times. The aqueous layer and the organic layer were separated. The solvent was first rotary evaporated to obtain a crude product. Finally, chloroform / petroleum ether was used as the eluent for column chromatography to obtain a white powder, namely, phenolic compound C, with a yield of 68.2%.

[0115] The reaction formula of the embodiment of the present application is as follows:

[0116]

[0117] Example 4

[0118] An embodiment of the present application provides a photoresist, which includes: 28 wt% of a phenolic resin with a molecular weight of 4000 to 8000, 4 wt% of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5 wt% of a silicone leveling agent, 2 wt% of a phenolic compound A prepared in Example 1, and 65.5 wt% of propylene glycol methyl ether acetate.

[0119] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer, leveling agent and phenolic compound A are added to the solvent according to the proportion and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, the mixture is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0120] Example 5

[0121] An embodiment of the present application provides a photoresist, which includes: 28 wt% of a phenolic resin with a molecular weight of 4000 to 8000, 4 wt% of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5 wt% of a silicone leveling agent, 2 wt% of a phenolic compound B prepared in Example 2, and 65.5 wt% of propylene glycol methyl ether acetate.

[0122] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer, leveling agent and phenolic compound B are added to the solvent according to the proportion and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, the mixture is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0123] Example 6

[0124] An embodiment of the present application provides a photoresist comprising: 28 wt % of a phenolic resin having a molecular weight of 4000 to 8000, 4 wt % of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5 wt % of a silicone leveling agent, 2 wt % of the phenolic compound C prepared in Example 3, and 65.5 wt % of propylene glycol methyl ether acetate.

[0125] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer, leveling agent and phenolic compound C are added to the solvent according to the proportion and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, the mixture is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0126] Example 7

[0127] An embodiment of the present application provides a photoresist, which includes: 28 wt% of a phenolic resin with a molecular weight of 4000 to 8000, 4 wt% of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5 wt% of a silicone leveling agent, 0.1 wt% of the phenolic compound C obtained in Example 3, and 67.4 wt% of propylene glycol methyl ether acetate.

[0128] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer, leveling agent and phenolic compound C are added to the solvent according to the proportion and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, the mixture is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0129] Example 8

[0130] An embodiment of the present application provides a photoresist, which includes: 28 wt% of a phenolic resin with a molecular weight of 4000 to 8000, 4 wt% of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5 wt% of a silicone leveling agent, 0.5 wt% of a phenolic compound C obtained in Example 3, and 67 wt% of propylene glycol methyl ether acetate.

[0131] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer, leveling agent and phenolic compound C are added to the solvent according to the proportion and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, the mixture is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0132] Example 9

[0133] An embodiment of the present application provides a photoresist, which includes: 28 wt% of a phenolic resin with a molecular weight of 4000 to 8000, 4 wt% of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5 wt% of a silicone leveling agent, 1 wt% of the phenolic compound C obtained in Example 3, and 66.5 wt% of propylene glycol methyl ether acetate.

[0134] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer, leveling agent and phenolic compound C are added to the solvent according to the proportion and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, the mixture is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0135] Example 10

[0136] An embodiment of the present application provides a photoresist, which includes: 28 wt% of a phenolic resin with a molecular weight of 4000 to 8000, 4 wt% of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5 wt% of a silicone leveling agent, 5 wt% of the phenolic compound C obtained in Example 3, and 62.5 wt% of propylene glycol methyl ether acetate.

[0137] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer, leveling agent and phenolic compound C are added to the solvent according to the proportion and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, the mixture is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0138] Example 11

[0139] An embodiment of the present application provides a photoresist, which includes: 28 wt% of a phenolic resin with a molecular weight of 4000 to 8000, 4 wt% of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5 wt% of a silicone leveling agent, 10 wt% of the phenolic compound C obtained in Example 3, and 57.5 wt% of propylene glycol methyl ether acetate.

[0140] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer, leveling agent and phenolic compound C are added to the solvent according to the proportion and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, the mixture is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0141] Comparative Example 1

[0142] The comparative example of the present application provides a photoresist, which includes: 28wt% of a phenolic resin with a molecular weight of 4000-8000, 4wt% of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5wt% of a silicone leveling agent and 67.5wt% of propylene glycol methyl ether acetate.

[0143] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer and leveling agent are added to the solvent according to the ratio and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, the mixture is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0144] Comparative Example 2

[0145] The comparative example of the present application provides a photoresist, which includes: 28wt% of a phenolic resin with a molecular weight of 4000 to 8000, 4wt% of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5wt% of a silicone leveling agent, 2wt% of a phenolic compound TPPA and 65.5wt% of propylene glycol methyl ether acetate.

[0146] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer, leveling agent and phenolic compound TPPA are added to the solvent according to the proportion and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, it is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0147] The structural formula of the phenolic compound TPPA is as follows:

[0148]

[0149] Comparative Example 3

[0150] The comparative example of the present application provides a photoresist, which includes: 28wt% of a phenolic resin with a molecular weight of 4000 to 8000, 4wt% of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5wt% of a silicone leveling agent, 2wt% of a phenolic compound BPA and 65.5wt% of propylene glycol methyl ether acetate.

[0151] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer, leveling agent and phenolic compound BPA are added to the solvent according to the proportion and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, it is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0152] The structural formula of the phenolic compound BPA is as follows:

[0153]

[0154] Comparative Example 4

[0155] The comparative example of the present application provides a photoresist, which includes: 28 wt% of a phenolic resin with a molecular weight of 4000 to 8000, 4 wt% of a 2,1,5-diazonaphthoquinone photosensitizer (PAC-1), 0.5 wt% of a silicone leveling agent, 15 wt% of the phenolic compound C obtained in Example 3, and 52.5 wt% of propylene glycol methyl ether acetate.

[0156] When preparing the photoresist, phenolic resin, diazonaphthoquinone sensitizer, leveling agent and phenolic compound C are added to the solvent according to the proportion and mixed, and then placed on a light-proof shaker at room temperature and mixed at a uniform speed for 12 hours. After mixing evenly, the mixture is filtered with a 0.2um microporous filter membrane to obtain the photoresist.

[0157] Test Example 1

[0158] The photoresists prepared in Examples 4 to 11 and Comparative Examples 1 to 4 were evenly coated on a bare silicon wafer by spin coating. After pre-baking, exposure, post-exposure baking, and development, a photoresist pattern was generated on the substrate. The photosensitivity, resolution, energy window EL, and focus window DOF of the photoresists were measured. The measured parameters are shown in Table 1.

[0159] Photospeed test method: Set different exposure energies, and after development, test the minimum energy that can open the photoresist pattern.

[0160] Resolution test method: the minimum line width that can be opened after development.

[0161] Energy window EL test method: Test the ratio of the energy of the upper and lower 10% of the target line width to its average energy.

[0162] Focus window DOF test method: the difference between the upper and lower limits of the focal length that can open the photoresist pattern.

[0163] The process conditions of photoresist are:

[0164] Substrate: 6” optical silicon wafer;

[0165] Pre-baking: 90C60s, CHP;

[0166] Post-baking: 115C60s, CHP;

[0167] Development: 60s, single development;

[0168] Exposure equipment: Nikon i9.

[0169] Table 1

[0170]

[0171]

[0172] From the comparison of Examples 4 to 6 and Comparative Example 1, it can be seen that the phenolic compound of the present application can be added to the photoresist to improve the photosensitivity, resolution, energy window EL and focus window DOF of the photoresist.

[0173] Comparison of Examples 4-6 with Comparative Examples 2-3 shows that phenolic compounds having the structure of the present application can be added as additives to photoresists to improve the photoresist's speed, resolution, energy window EL, and focus window DOF. However, phenolic compounds not having the structure of the present application, when added to photoresists, do not improve the photoresist's speed, resolution, energy window EL, and focus window DOF.

[0174] From the comparison of Examples 4, 7 to 11 and Comparative Example 4, it can be seen that when the addition amount of the phenolic additive is 2 to 10 wt%, the photosensitivity of the photoresist is 140 mJ, the resolution is 350 nm, the energy window EL ≥ 20%, and the Focus window DOF ≥ 1.8 um; when the addition amount of the phenolic additive is 15 wt%, the photosensitivity, resolution, energy window EL and Focus window DOF of the photoresist are significantly deteriorated.

[0175] In summary, the phenolic compound provided in the embodiment of the present application can improve the resolution of the photoresist and at the same time make the photoresist have better lithography performance, which is specifically manifested in better sensitivity, greater contrast, a more vertical side wall angle morphology and a larger process window.

[0176] The foregoing description is merely a specific embodiment of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A use of a phenolic compound as an additive in a photoresist, wherein the photoresist is an i-line naphthoquinone diazide photoresist, the photoresist comprising a phenolic compound, a phenolic resin, a naphthoquinone diazide sensitizer, a leveling agent, and a solvent, wherein the phenolic compound is added in an amount of 0.1 to 10 wt % of the photoresist; The structural formula of the phenolic compound is as follows: 、 or 。 2. A photoresist, characterized in that The photoresist is an i-line naphthoquinone diazide photoresist, which includes a phenolic compound, a phenolic resin, a naphthoquinone diazide sensitizer, a leveling agent and a solvent, wherein the amount of the phenolic compound added is 0.1-10 wt % of the photoresist; The structural formula of the phenolic compound is as follows: 、 or 。 3. The photoresist according to claim 2, characterized in that The added amount of the phenolic compound is 0.1-5 wt % of the photoresist.

4. The photoresist according to claim 2, characterized in that The added amount of the phenolic compound is 0.1-2 wt % of the photoresist.

5. The photoresist according to claim 2, characterized in that The photoresist comprises 10-30 wt % of the phenolic resin, 2-10 wt % of the diazonaphthoquinone photosensitizer, 0.1-5 wt % of the leveling agent, 40-80 wt % of the solvent and 0.1-10 wt % of the phenolic compound.

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