A photoresist and its use

Abstract

The application provides a photoresist and application thereof, and belongs to the technical field of semiconductor and integrated circuit. The photoresist comprises 10wt%-30wt% phenolic resin, 2wt%-10wt% diazonaphthoquinone photosensitizer and 0.1wt%-10wt% additive. The application adds the additive containing halogen into the diazonaphthoquinone type photoresist, the additive can interact with other components in the photoresist, thereby improving the photosensitivity of the photoresist, and the photoresist can have good photoetching performance, and the specific performance is that the side wall has a relatively vertical appearance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor and integrated circuit, in particular to a photoresist and application thereof. BACKGROUND

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

[0003] Photoresist is a key material required for integrated circuit manufacturing. The 365nm (i-line) photoresist is based on phenolic resin, diazonaphthoquinone and other main materials. Through photoetching process procedures such as exposure and development, the patterns of the mask plate are transferred and copied to the silicon wafer, and the photoresist is widely used in the process of several hundred nanometers to several microns in integrated circuit manufacturing.

[0004] In the chip packaging process, 7-20um thick film photoresist is needed to manufacture various point and line patterns on the surface of the substrate. The photosensitivity of the photoresist greatly affects the production efficiency of the packaging process. The main problem of the thick film photoresist based on phenolic resin / diazonaphthoquinone is insufficient photosensitivity. SUMMARY

[0005] The present application provides a photoresist and application thereof, which can improve the photosensitivity of the photoresist and make the photoresist have good photoetching performance.

[0006] The embodiments of the present application are implemented as follows:

[0007] In a first aspect, the present application provides a photoresist, which comprises 10wt%-30wt% phenolic resin, 2wt%-10wt% diazonaphthoquinone photosensitizer and 0.1wt%-10wt% additive.

[0008] The structural formula of the additive is as follows:

[0009]

[0010] wherein R1 is selected from X, C 1～6 alkyl-X or (ph) m -X.

[0011] R2 is selected from H, Y, C 1～6 alkyl-Y, (ph) n -Y or C 1～4 -(ph) n -Y.

[0012] X and Y are each independently selected from F, Cl, Br or I, and m and n are integers from 1 to 3.

[0013] R3 is selected from

[0014] In the above technical solution, the halogen-containing additive is added in the diazonium naphthoquinone type photoresist, the additive can interact with other components in the photoresist, thereby improving the photosensitivity of the photoresist, and the photoresist can have good photoetching performance, specifically showing a relatively vertical side wall morphology.

[0015] In combination with the first aspect, in a first possible example of the first aspect of the present application, R1 is selected from X, C 1～6 alkyl-X or (ph) m -X.

[0016] R2 is selected from H, Y, C 1～6 alkyl-Y or (ph) n -Y.

[0017] In combination with the first aspect, in a second possible example of the first aspect of the present application, R2 is selected from H, Y or C 1～6 alkyl-Y.

[0018] In combination with the first aspect, in a third possible example of the first aspect of the present application, R1 is selected from X or C 1～6 alkyl-X.

[0019] In combination with the first aspect, in a fourth possible example of the first aspect of the present application, the molecular weight of the phenolic resin is 4000-10000.

[0020] Optionally, the phenolic resin has the following structural formula:

[0021]

[0022] wherein a, b or c can be 0.

[0023] In combination with the first aspect, in a fifth possible example of the first aspect of the present application, the diazonium naphthoquinone photosensitizer includes a 2,1,4 type diazonium naphthoquinone photosensitizer and / or a 2,1,5 type diazonium naphthoquinone photosensitizer.

[0024] In combination with the first aspect, in a sixth possible example of the first aspect of the present application, the photoresist further includes 0.1wt%-5wt% of a leveling agent.

[0025] Optionally, the leveling agent includes any one or more of a siloxane leveling agent, a polyether leveling agent and a fluorine-containing polymethyl methacrylate leveling agent.

[0026] Optionally, the leveling agent is a siloxane leveling agent.

[0027] With reference to the first aspect, in a seventh possible implementation of the first aspect of the present application, the photoresist further includes 40wt%-80wt% of the solvent.

[0028] Optionally, the solvent includes any one or more of propylene glycol methyl ether acetate, 2-heptanone, and ethyl lactate.

[0029] With reference to the first aspect, in an eighth possible implementation of the first aspect of the present application, the photoresist includes 20wt%-30wt% of the phenolic resin, 5wt%-8wt% of the diazonaphthoquinone photosensitizer, 0.1wt%-2wt% of the leveling agent, 40wt%-80wt% of the solvent, and 0.1wt%-3wt% of the additive.

[0030] In the second aspect, the present application provides an application of the photoresist to integrated circuits and chip packaging.

[0031] Optionally, the thickness of the photoresist is 7μm-20μm.

[0032] Optionally, the developer used for the photoresist is a potassium hydroxide solution.

[0033] In the above technical solution, the photoresist of the present application can be applied to the integrated circuit and chip packaging process in a thick coating manner. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0035] Figure 1 The topography of the photoresist of the present application Example 1 after development with a KOH developer;

[0036] Figure 2 The topography of the photoresist of the present application Example 2 after development with a KOH developer;

[0037] Figure 3 The topography of the photoresist of the present application Example 3 after development with a KOH developer;

[0038] Figure 4 The topography of the photoresist of the present application Example 4 after development with a KOH developer;

[0039] Figure 5 The topography of the photoresist of the present application Example 5 after development with a KOH developer;

[0040] Figure 6 A topographic map of the photoresist of Example 6 of the present application after development with a KOH developer;

[0041] Figure 7 A topographic map of the photoresist of Example 7 of the present application after development with a KOH developer;

[0042] Figure 8 A topographic map of the photoresist of Example 8 of the present application after development with a KOH developer;

[0043] Figure 9 A topographic map of the photoresist of Example 9 of the present application after development with a KOH developer;

[0044] Figure 10 A topographic map of the photoresist of Comparative Example 1 of the present application after development with a KOH developer;

[0045] Figure 11 A topographic map of the photoresist of Comparative Example 2 of the present application after development with a KOH developer;

[0046] Figure 12 A topographic map of the photoresist of Example 1 of the present application after development with a TMAH developer. DETAILED DESCRIPTION

[0047] The embodiments of the present application will be described in detail below with examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application. The specific conditions are not specified in the examples, and the conventional conditions or the conditions recommended by the manufacturer are used. The reagents or instruments used are not specified by the manufacturer, and are all conventional products that can be purchased on the market.

[0048] At present, with the vigorous development of new infrastructure such as cloud computing, Internet of Things, 5G communication, artificial intelligence, integrated circuits, as one of the core industries of the information industry, have also embarked on the road of rapid development. Photoresist is a key material required for integrated circuit manufacturing. 365nm (i-line) photoresist is based on phenolic resin, diazonaphthoquinone and other main materials, and through photoetching process procedures such as exposure and development, the patterns of the mask plate are transferred and copied to the silicon wafer, and are widely used in the process of several hundred nanometers to several microns in integrated circuit manufacturing.

[0049] The present inventors have noticed that in the chip packaging process, it is necessary to use 7μm-20μm thick film photoresist to manufacture various point and line patterns on the surface of the substrate, and the photosensitivity of the photoresist greatly affects the production efficiency of the packaging process, but the existing phenolic resin / diazonaphthoquinone thick film photoresist has insufficient photosensitivity, which will cause problems such as side wall tilt.

[0050] In order to improve the problem of insufficient photosensitivity of the phenolic resin / diazo naphthoquinone thick film photoresist, the inventors found that the problem can be solved by adjusting the photosensitizer and the resin, but due to the structural change and the limitation of the physical and chemical properties of the two main materials, the comprehensive performance of the photoresist, such as photosensitivity, heat resistance, resolution, process window, etc., usually needs to be adjusted multiple times to balance the resolution, photosensitivity and other performance optimization, which is difficult to operate and difficult to realize.

[0051] Based on the above considerations, in order to alleviate the problem of insufficient photosensitivity of the phenolic resin / diazo naphthoquinone thick film photoresist, the inventors have designed a photoresist by adding a halogen-containing additive to the diazo naphthoquinone photoresist. The additive can interact with other components in the photoresist, thereby improving the photosensitivity of the photoresist, and the photoresist can have good photoetching performance, specifically a relatively vertical side wall morphology.

[0052] The following describes a photoresist according to an embodiment of the present application:

[0053] The present application provides a photoresist, which comprises 10wt%-30wt% phenolic resin, 2wt%-10wt% diazo naphthoquinone photosensitizer, 0.1wt%-10wt% additive, 0.1wt%-5wt% leveling agent and 40wt%-80wt% solvent.

[0054] The structural formula of the phenolic resin is as follows:

[0055]

[0056] a, b or c can be 0.

[0057] For example, a can be 0, b and c are not 0; or b can be 0, a and c are not 0; or c can be 0, a and b are 0; or a and b can be 0, c is not 0; or a and c can be 0, b is not 0; or b and c are not 0, a is 0; or a, b and c are not 0.

[0058] The molecular weight M of the phenolic resin is 4000-10000. w

[0059] The diazo naphthoquinone photosensitizer includes 2,1,4 type diazo naphthoquinone photosensitizer and / or 2,1,5 type diazo naphthoquinone photosensitizer, and the optional structures are as follows:

[0060] PAC-1: R = H, or

[0061] PAC-2: R = H, or

[0062] ​The additive is a halogen-containing compound having the formula:

[0063]

[0064] wherein R1 is selected from X, C 1～6 alkyl-X, or (ph) m -X.

[0065] R2 is selected from H, Y, C 1～6 alkyl-Y, (ph) n -Y, or C 1～4 -(ph) n -Y.

[0066] X, Y are each independently selected from F, CI, Br, or I, m, n are taken from an integer from 1 to 3.

[0067] R3 is selected from

[0068] Optionally, R1 is selected from X or C 1～6 alkyl-X.

[0069] Optionally, R1 is selected from X.

[0070] Optionally, R1 is selected from CI.

[0071] Optionally, R2 is selected from H, Y, C 1～6 alkyl-Y, or (ph) n -Y.

[0072] Optionally, R2 is selected from H, Y, or C 1～6 alkyl-Y.

[0073] Optionally, R2 is selected from H.

[0074] The leveling agent includes any one or more of a silicone-based leveling agent, a polyether-based leveling agent, and a fluorine-containing polymethyl methacrylate-based leveling agent.

[0075] Optionally, the leveling agent is a silicone-based leveling agent.

[0076]

[0077] The solvent includes any one or more of propylene glycol methyl ether acetate, 2-heptanone, and ethyl lactate.

[0078] As an example, the solvent can be propylene glycol methyl ether acetate, 2-heptanone, or ethyl lactate alone, or can be a mixture of propylene glycol methyl ether acetate and 2-heptanone, or can be a mixture of propylene glycol methyl ether acetate and ethyl lactate, or can be a mixture of 2-heptanone and ethyl lactate, or can be a mixture of propylene glycol methyl ether acetate, 2-heptanone, and ethyl lactate.

[0079] As an example, the photoresist can include 10wt%, 12wt%, 15wt%, 18wt%, 20wt%, 22wt%, 25wt%, 28wt% or 30wt% phenolic resin, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt% or 10wt% diazonaphthoquinone photosensitizer, 0.1wt%, 0.2wt%, 0.5wt%, 0.8wt%, 1wt%, 2wt%, 5wt%, 8wt%, 10wt% additive, 0.1wt%, 0.2wt%, 0.5wt%, 0.8wt%, 1wt%, 2wt%, 3wt%, 4wt% or 5wt% leveling agent and 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt% or 80wt% solvent.

[0080] Alternatively, the photoresist includes 20wt%~30wt% phenolic resin, 5wt%~8wt% diazonaphthoquinone photosensitizer, 0.1wt%~2wt% leveling agent, 40wt%~80wt% solvent and 0.1wt%~3wt% additive.

[0081] The present application adds halogen-containing additive in diazonaphthoquinone type photoresist, the additive can interact with other components in the photoresist, thereby improving the photosensitivity of the photoresist, and the photoresist can have good photoetching performance, which is specifically manifested in the relatively vertical morphology of the side wall.

[0082] The present application also provides a use of the above photoresist in integrated circuits and chip packaging.

[0083] The preparation method of the photoresist includes the following steps: mixing phenolic resin, diazonaphthoquinone photosensitizer, leveling agent, additive and solvent according to the proportion, and placing them in a shaker at 5~30℃ and in the dark for uniform mixing for 12h to obtain a mixed solution, and then filtering the mixed solution with a 0.2μm pore size microporous filter membrane to obtain the photoresist.

[0084] Alternatively, when the photoresist is coated on a silicon wafer, the thickness of the photoresist is 7μm~20μm.

[0085] Alternatively, the developing solution used for the photoresist is potassium hydroxide solution.

[0086] The photoresist and its use according to the present application are further described in detail below in combination with examples.

[0087] Example 1

[0088] The photoresist provided by the embodiment of the present application comprises 28wt% phenolic resin, 4wt% 2,1,4 type diazonium naphthoquinone photosensitizer (PAC-1), 1wt% siloxane leveling agent, 65wt% solvent and 2wt% additive.

[0089] The phenolic resin has a structure of m / p-cresol 6 / 4 and a molecular weight of 6220.

[0090] The additive has the following structural formula:

[0091]

[0092] The additive is prepared by the following method:

[0093] Oxalyl chloride (10 mL) was added dropwise to a slurry of p-chlorobenzoic acid (22 g) in dichloromethane (200 mL) containing 0.5 mL DMF, and the reaction mixture was stirred at room temperature for 24 hours, concentrated under reduced pressure, and co-evaporated with toluene. To the residue was added 14 mL of t-butanol, and the mixture was cooled to 0°C, and the reaction mixture was stirred for another 1 hour, and then treated with 500 mL of saturated sodium bicarbonate solution. After stirring for 5 minutes, the precipitate was separated, and the organic phase was washed with saturated sodium chloride solution, dried over magnesium sulfate, and concentrated to obtain 20.1 g of product (80% yield) as a dark oil.

[0094]

[0095] HNMR: CDCl3, 400MHz, 1.43ppm (s, 9H), 7.61 (d, 2H), 7.99 (d, 2H).

[0096] The photoresist is prepared by the following method:

[0097] The phenolic resin, diazonium naphthoquinone photosensitizer, leveling agent, additive and solvent are mixed according to the proportion, and placed on a shaker in the dark and at 25°C to mix at a constant speed for 12 hours to obtain a mixed solution, and then the mixed solution is filtered through a microporous filter membrane with a pore size of 0.2 μm to obtain the photoresist.

[0098] Example 2

[0099] The photoresist provided by the embodiment of the present application comprises 28wt% phenolic resin, 4wt% 2,1,4 type diazonium naphthoquinone photosensitizer (PAC-1), 1wt% siloxane leveling agent, 65wt% solvent and 2wt% additive.

[0100] The phenolic resin has a structure of m / p-cresol 6 / 4 and a molecular weight of 6220.

[0101] The additive has the following structural formula:

[0102]

[0103] The additive is prepared by the following method:

[0104] Oxalyl chloride (10 mL) was added dropwise to a slurry of p-bromobenzoic acid (23.7 g) in dichloromethane (200 mL) containing 0.5 mL DMF over 30 minutes and the reaction mixture was stirred at 40°C for 24 hours, concentrated under reduced pressure and co-evaporated with toluene. To the residue was added 14 mL of t-butanol, the mixture was cooled to 0°C and the reaction mixture was stirred for a further hour before treating with 500 mL of saturated sodium bicarbonate solution. After stirring for 5 minutes, the precipitate was separated, the organic phase was washed with saturated sodium chloride solution, dried over magnesium sulfate and concentrated to give 19.23 g of product (76% yield) as an oil.

[0105]

[0106] HNMR: CDC13, 400 MHz, 1.43 ppm (s, 9H), 7.71 ppm (d, 2H), 7.74 ppm (d, 2H).

[0107] The photoresist is prepared by the following method:

[0108] The phenolic resin, diazonium naphthoquinone photosensitizer, leveling agent, additive and solvent are mixed according to the ratio, and the mixture is placed in a shaking bed in the dark and at 25°C, and uniformly mixed at a constant speed for 12 hours to prepare a mixed solution. The mixed solution is filtered with a microporous filter membrane with a pore size of 0.2 μm to prepare a photoresist.

[0109] Example 3

[0110] The photoresist provided by the embodiments of the present application comprises 28 wt% of phenolic resin, 4 wt% of 2,1,4 diazonium naphthoquinone photosensitizer (PAC-1), 1 wt% of siloxane leveling agent, 65 wt% of solvent and 2 wt% of additive.

[0111] The phenolic resin has a structure of m / p-cresol 6 / 4 and a molecular weight of 6220.

[0112] The additive has the following structural formula:

[0113]

[0114] The additive is prepared by the following method:

[0115] Oxalyl chloride (10 mL) was added dropwise to a slurry of p-chloromethylbenzoic acid (24 g) in dichloromethane (200 mL) containing 0.5 mL of DMF over 30 minutes and the reaction mixture was stirred at 40°C for 24 hours, concentrated under reduced pressure and co-evaporated with toluene. To the residue was added 14 mL of t-butanol, the mixture was cooled to 0°C and the reaction mixture was stirred for another hour before treating with 500 mL of saturated sodium bicarbonate solution. After stirring for 5 minutes, the precipitate was separated, the organic phase was washed with saturated sodium chloride solution, dried over magnesium sulfate and concentrated to give 20.4 g of product (77.3% yield) as an oil.

[0116]

[0117] HNMR: CDC13, 400 MHz, 1.43 ppm (s, 9H), 4.61 ppm (s, 2H), 7.41 ppm (d, 2H), 7.99 ppm (d, 2H).

[0118] The photoresist was prepared by the following method:

[0119] The phenolic resin, diazonium naphthoquinone photosensitizer, leveling agent, additive and solvent were mixed according to the ratio, and placed in a shaking bed at 25°C for 12 hours to prepare a mixed solution. Then the mixed solution was filtered by a microporous filter membrane with a pore size of 0.2 μm to prepare the photoresist.

[0120] Example 4

[0121] The photoresist provided by the embodiment of the present application comprises 28 wt% of phenolic resin, 4 wt% of 2,1,4 diazonium naphthoquinone photosensitizer (PAC-1), 1 wt% of siloxane leveling agent, 65 wt% of solvent and 2 wt% of additive.

[0122] The phenolic resin has a structure of m / p-cresol 6 / 4 and a molecular weight of 6220.

[0123] The additive has the following structural formula:

[0124]

[0125] The additive was prepared by the following method:

[0126] Oxalyl chloride (10 mL) was added dropwise to a slurry of 4'-chloro-4-biphenylcarboxylic acid (33 g) in 0.5 mL DMF in dichloromethane (200 mL) over 30 minutes, the reaction mixture was stirred at 50°C for 24 hours, concentrated under reduced pressure and co-evaporated with toluene. To the residue was added 14 mL of t-butanol, the mixture was cooled to 0°C, the reaction mixture was stirred for another hour, then treated with 500 mL of saturated sodium bicarbonate solution. After stirring for 5 minutes, the precipitate was separated, the organic phase was washed with saturated sodium chloride solution, dried over magnesium sulfate and concentrated to give 24.4 g of product (72% yield) as an oil.

[0127]

[0128] HNMR: CDCl3, 400MHz, 1.43ppm (s, 9H), 7.62ppm (s, 2H), 7.76ppm (d, 2H), 8.04ppm (d, 2H), 8.11ppm (d, 2H).

[0129] The photoresist was prepared by the following method:

[0130] The phenolic resin, diazonium naphthoquinone photosensitizer, leveling agent, additive and solvent were mixed according to the ratio, and placed on a shaker in the dark and at 25°C for uniform mixing for 12 h to prepare a mixed solution, and then the mixed solution was filtered with a microporous filter membrane with a pore size of 0.2 μm to prepare the photoresist.

[0131] Example 5

[0132] The photoresist provided by the embodiments of the present application comprises 28 wt% phenolic resin, 4 wt% 2,1,4 diazonium naphthoquinone photosensitizer (PAC-1), 1 wt% siloxane leveling agent, 65 wt% solvent and 2 wt% additive.

[0133] The phenolic resin has a structure of m / p-cresol 6 / 4 and a molecular weight of 6220.

[0134] The additive has the following structural formula:

[0135]

[0136] The additive was prepared by the following method:

[0137] Oxalyl chloride (10 mL) was added dropwise to a slurry of 4-chloro-2-fluorobenzoic acid (24.7 g) in 0.5 mL DMF in dichloromethane (200 mL) over 30 minutes, the reaction mixture was stirred at room temperature for 24 hours, concentrated under reduced pressure, then co-evaporated with toluene. To the residue was added 14 mL of t-butanol, the mixture was cooled to 0°C, the reaction mixture was stirred for another hour, then treated with 500 mL of saturated sodium bicarbonate solution. After stirring for 5 minutes, the precipitate was separated, the organic phase was washed with saturated sodium chloride solution, dried over magnesium sulfate and concentrated to give 20.4 g of product (72% yield) as an oil.

[0138]

[0139] HNMR: CDCl3, 400MHz, 1.43ppm (s, 9H), 7.37ppm (s, 1H), 7.75ppm (d, 1H), 7.89ppm (d, 1H).

[0140] The photoresist was prepared by the following method:

[0141] The phenolic resin, diazonium naphthoquinone photosensitizer, leveling agent, additive and solvent were mixed according to the ratio, and placed in a shaking bed in the dark and at 25°C for uniform mixing at a constant speed for 12 h to prepare a mixed solution, and then the mixed solution was filtered with a microporous filter membrane with a pore size of 0.2 μm to prepare the photoresist.

[0142] Example 6

[0143] The photoresist provided by the embodiments of the present application comprises 28 wt% of phenolic resin, 4 wt% of 2,1,4 diazonium naphthoquinone photosensitizer (PAC-1), 1 wt% of siloxane leveling agent, 65 wt% of solvent and 2 wt% of additive.

[0144] The phenolic resin has a structure of m / p-cresol 6 / 4 and a molecular weight of 6220.

[0145] The additive has the following structural formula:

[0146]

[0147] The additive was prepared by the following method:

[0148] Oxalyl chloride (10 mL) was added dropwise to a slurry of 2,4-dichlorobenzoic acid (27 g) in dichloromethane (200 mL) containing 0.5 mL DMF over 30 minutes and the reaction mixture was stirred at room temperature for 24 hours, concentrated under reduced pressure and co-evaporated with toluene. To the residue was added 14 mL of t-butanol, the mixture was cooled to 0°C and the reaction mixture was stirred for a further 1 hour before treating with 500 mL of saturated sodium bicarbonate solution. After stirring for 5 minutes, the precipitate was separated, the organic phase was washed with saturated sodium chloride solution, dried over magnesium sulfate and concentrated to give 20.8 g of product (71.5% yield) as an oil.

[0149]

[0150] HNMR: CDCI3, 400 MHz, 1.43 ppm (s, 9H), 7.48 ppm (s, 1H), 7.64 ppm (d, 1H), 7.91 ppm (d, 1H).

[0151] The photoresist was prepared by the following method:

[0152] The phenolic resin, diazonium naphthoquinone photosensitizer, leveling agent, additive and solvent were mixed according to the ratio, and placed in a shaker at 25°C for 12 hours to prepare a mixed solution. Then the mixed solution was filtered by a microporous filter membrane with a pore size of 0.2 μm to prepare the photoresist.

[0153] Example 7

[0154] The photoresist provided by the embodiment of the present application comprises 28 wt% of phenolic resin, 4 wt% of 2,1,4 diazonium naphthoquinone photosensitizer (PAC-1), 1 wt% of siloxane leveling agent, 65 wt% of solvent and 2 wt% of additive.

[0155] The phenolic resin has a structure of m / p-cresol 6 / 4 and a molecular weight of 6220.

[0156] The additive has the following structural formula:

[0157]

[0158] The additive was prepared by the following method:

[0159] Oxalyl chloride (10 mL) was added dropwise to a slurry of 2-bromomethyl 4-chlorobenzoic acid (35.4 g) in dichloromethane (200 mL) containing 0.5 mL DMF over 30 minutes and the reaction mixture was stirred at room temperature for 24 hours, concentrated under reduced pressure and co-evaporated with toluene. To the residue was added 14 mL of t-butanol, the mixture was cooled to 0°C and the reaction mixture was stirred for a further hour before treating with 500 mL of saturated sodium bicarbonate solution. After stirring for 5 minutes, the precipitate was separated, the organic phase was washed with saturated sodium chloride solution, dried over magnesium sulfate and concentrated to give 24.5 g of product (68% yield) as an oil.

[0160]

[0161] HNMR: CDCI3, 400 MHz, 1.43 ppm (s, 9H), 4.55 ppm (s, 2H), 7.57 ppm (s, 2H), 8.00 ppm (d, 1H).

[0162] The photoresist was prepared by the following method:

[0163] The phenolic resin, diazonium naphthoquinone photosensitizer, leveling agent, additive and solvent were mixed according to the ratio, and placed in a shaker at 25°C for 12 hours to prepare a mixed solution. Then the mixed solution was filtered by a microporous filter membrane with a pore size of 0.2 μm to prepare the photoresist.

[0164] Example 8

[0165] The photoresist provided by the embodiments of the present application comprises 28 wt% of phenolic resin, 4 wt% of 2,1,4 diazonium naphthoquinone photosensitizer (PAC-1), 1 wt% of siloxane leveling agent, 65 wt% of solvent and 2 wt% of additive.

[0166] The phenolic resin has a structure of m / p-cresol 6 / 4 and a molecular weight of 6220.

[0167] The additive has the following structural formula:

[0168]

[0169] The additive was prepared by the following method:

[0170] Oxalyl chloride (10 mL) was added dropwise to a slurry of 4',5-dichloro-[l,l'-biphenyl]-2-carboxylic acid (38 g) in 0.5 mL DMF in dichloromethane (200 mL) over 30 minutes and the reaction mixture was stirred at room temperature for 24 hours, concentrated under reduced pressure and co-evaporated with toluene. To the residue was added 14 mL of t-butanol and the mixture was cooled to 0°C and the reaction mixture was stirred for a further hour before treating with 500 mL of saturated sodium bicarbonate solution. After stirring for 5 minutes, the precipitate was separated, the organic phase was washed with saturated sodium chloride solution, dried over magnesium sulfate and concentrated to give 23.6 g of product (62% yield) as a brown solid.

[0171]

[0172] HNMR: CDC13, 400 MHz, 1.43 ppm (s, 9H), 7.63 ppm (d, 2H), 7.71 ppm (s, 1H), 7.78 ppm (s, 2H), 8.08 ppm (d, 1H), 8.17 ppm (d, 1H).

[0173] The photoresist was prepared by the following method:

[0174] The phenolic resin, diazonium naphthoquinone photosensitizer, leveling agent, additive and solvent were mixed according to the ratio, and placed in a shaker at 25°C for 12 hours to prepare a mixed solution. Then, the mixed solution was filtered through a microporous filter membrane with a pore size of 0.2 μm to prepare the photoresist.

[0175] Example 9

[0176] The photoresist provided by the embodiments of the present application comprises 28 wt% of phenolic resin, 4 wt% of 2,1,4 diazonium naphthoquinone photosensitizer (PAC-1), 1 wt% of siloxane leveling agent, 65 wt% of solvent and 2 wt% of additive.

[0177] The phenolic resin has a structure of m / p-cresol 6 / 4 and a molecular weight of 6220.

[0178] The additive has the following structural formula:

[0179]

[0180] The additive was prepared by the following method:

[0181] Oxalyl chloride (10 mL) was added dropwise to a slurry of 4',5-dichloro-3'-methyl-[l,l'-biphenyl]-2-carboxylic acid (46 g) in 0.5 mL DMF in dichloromethane (200 mL) over 30 minutes and the reaction mixture was stirred at room temperature for 24 hours, concentrated under reduced pressure and co-evaporated with toluene. To the residue was added 14 mL of t-butanol and the mixture was cooled to 0°C and the reaction mixture was stirred for an additional hour before treating with 500 mL of saturated sodium bicarbonate solution. After stirring for 5 minutes, the precipitate was isolated, the organic phase was washed with saturated sodium chloride solution, dried over magnesium sulfate and concentrated to give 24.5 g of product (61.8% yield) as a brown solid.

[0182]

[0183] HNMR: CDC13, 400 MHz, 1.43 ppm (s, 9H), 2.26 ppm (s, 3H) 7.56 ppm (d, IH), 7.68 ppm (s, IH), 7.70 ppm (d, IH), 7.72 ppm (s, IH), 8.08 ppm (s, 2H), 8.16 ppm (d, IH).

[0184] The photoresist was prepared by the following method:

[0185] The phenolic resin, diazonium naphthoquinone photosensitizer, leveling agent, additive and solvent were mixed according to the proportion, and placed in a shaker at 25°C for 12 hours to prepare a mixed solution. Then, the mixed solution was filtered by a microporous filter membrane with a pore size of 0.2 μm to prepare the photoresist.

[0186] Comparative Example 1

[0187] The photoresist of the present application comprises 28 wt% of phenolic resin, 4 wt% of 2,1,4 diazonium naphthoquinone photosensitizer (PAC-1), 1 wt% of siloxane leveling agent and 67 wt% of solvent.

[0188] The phenolic resin has a structure of m / p-cresol 6 / 4 and a molecular weight of 6220.

[0189] The photoresist was prepared by the following method:

[0190] The phenolic resin, diazonium naphthoquinone photosensitizer, leveling agent and solvent were mixed according to the proportion, and placed in a shaker at 25°C for 12 hours to prepare a mixed solution. Then, the mixed solution was filtered by a microporous filter membrane with a pore size of 0.2 μm to prepare the photoresist.

[0191] Comparative Example 2

[0192] The embodiment of the present application provides a photoresist, which comprises 28wt% of phenolic resin, 4wt% of 2,1,4 diazonaphthoquinone photosensitizer (PAC-1), 1wt% of siloxane leveling agent, 65wt% of solvent and 2wt% of additive.

[0193] The phenolic resin is of m / p-cresol 6 / 4 structure and has a molecular weight of 6220.

[0194] The additive has the following structural formula:

[0195]

[0196] The additive is purchased from Beijing Bailingwei Technology Co., Ltd.

[0197] The photoresist is prepared by the following method:

[0198] The phenolic resin, diazonaphthoquinone photosensitizer, leveling agent, additive and solvent are mixed according to the proportion, and are placed on a shaker in the dark and at 25°C to uniformly mix for 12h to prepare a mixed solution, and then the mixed solution is filtered by using a micropore filter membrane with a pore size of 0.2μm to prepare the photoresist.

[0199] Test Example 1

[0200] The photoresists prepared in Examples 1-10 and Comparative Examples 1-2 are uniformly coated on bare silicon wafers by using a spin coating method, and the evaluation indexes of the photoresists, except for resolution and photosensitivity, mainly include photosensitivity and cross-sectional morphology performance, and the results are shown in Table 1, and the morphology diagrams of the photoresists of Examples 1-10 and Comparative Examples 1-2 after development are shown in 1-11.

[0201] The process conditions of the photoresist are as follows:

[0202] Substrate: 6" silicon wafer;

[0203] Pre-baking: 90C 60s, CHP;

[0204] Post-baking: 115C 60s, CHP;

[0205] Development: 60s, single development, KOH (0.75wt%);

[0206] Exposure equipment: Nikon i9;

[0207] Film thickness: 7μm.

[0208] The photosensitivity test method is as follows: Photoresist is coated on the substrate, solvent residue is reduced by pre-baking, the substrate is placed in the photolithography machine, different exposure energies are set for different areas, and then KOH developer is used to develop it for 60 seconds and the film thickness after development is measured. Since the designed system is a positive photoresist system, its film thickness will decrease with the increase of exposure energy until it becomes zero. The first exposure energy that completely develops the photoresist (i.e., the film thickness is 0) is its photosensitivity value.

[0209] The contrast ratio is tested by plotting the residual film thickness and corresponding exposure energy in different regions. The slope is the contrast ratio. A higher contrast ratio corresponds to a straighter morphology and better lithography performance.

[0210] The sidewall testing method is as follows: after forming a pattern with a mask, measure the angle between the photoresist and the substrate in its cross-section.

[0211] Table 1. Development effects of Examples 1-10 and Comparative Examples 1-2

[0212]

[0213]

[0214] As can be seen from Examples 1-9, the photoresist of this application exhibits high photosensitivity and photolithographic performance, with a specific photosensitivity value of only 215 mJ / cm. 2 ~250mj / cm 2 The sidewall angles are 85.1° to 88.2°, and the contrast ratios are 3.91 to 5.02. The sidewall angle of the photoresist in Example 1 is closest to 90°. In Examples 4 and 8-9, the sidewall angles are lower than those in Example 1 because the additives have at least two benzene rings in their structure, resulting in greater steric hindrance.

[0215] A comparison of Comparative Example 1 and Example 1 shows that the photoresist of Comparative Example 1 contains no additives, has a photosensitivity of 420 mJ / cm², a sidewall angle of 63.3°, and a contrast ratio of 1.24. The photosensitivity of the photoresist of Comparative Example 1 is significantly higher than that of the photoresist of Example 1, the sidewall angle of the photoresist of Comparative Example 1 is significantly smaller than that of the photoresist of Example 1, and the contrast ratio of the photoresist of Comparative Example 1 is significantly smaller than that of the photoresist of Example 1. In other words, the photosensitivity and lithographic performance of the photoresist of Comparative Example 1 are both poor.

[0216] As can be seen from the comparison between Comparative Example 2 and Example 1, the photoresist of Comparative Example 2 contains an existing additive, the photosensitivity value is 390 mj / cm2, the sidewall angle is 72.0°, and the contrast is 1.63. The photosensitivity value of the photoresist of Comparative Example 2 is much greater than that of the photoresist of Example 1, the sidewall angle of the photoresist of Comparative Example 2 is much smaller than that of the photoresist of Example 1, and the contrast of the photoresist of Comparative Example 2 is much smaller than that of the photoresist of Example 1. That is, the photosensitivity and the photoetching performance of the photoresist of Comparative Example 2 are both poor.

[0217] Test Example 2

[0218] The photoresist prepared in Example 1 was uniformly coated on a bare silicon wafer by spin coating. The evaluation indexes of the photoresist, except for the resolution and photosensitivity, mainly include the photosensitivity and the cross-sectional morphology performance. The results are shown in Table 2, and the morphology diagram of the photoresist after development of Example 1 is shown in FIG. 12.

[0219] The process conditions of the photoresist are as follows:

[0220] Substrate: 6" silicon wafer

[0221] Pre-baking: 90 C for 60 s, CHP

[0222] Post-baking: 115 C for 60 s, CHP

[0223] Development: 60 s, single development, TMAH (2.38 wt%)

[0224] Exposure equipment: Nikon i9

[0225] Film thickness: 7 μm

[0226] Table 2 Development effect of Example 1

[0227] Item Photosensitivity value (mj / cm 2 )]]> Side wall angle (°) Contrast Example 1 415 59.3 2.05

[0228] As can be seen from the above, the photoresist of Example 1 is developed by using TMAH developer, the photosensitivity value is 415 mj / cm2, the sidewall angle is 59.3°, and the contrast is 2.05. Compared with the development by using KOH, the development by using TMAH developer leads to a decrease in photosensitivity, and a significant decrease in the sidewall angle and the contrast.

[0229] The above only describes specific embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A photoresist, characterized by, The photoresist comprises 10wt%-30wt% phenolic resin, 2wt%-10wt% diazonaphthoquinone photosensitizer and 0.1wt%-10wt% additive. The structural formula of the additive is as follows: wherein R1is selected from X, C 1~6 alkyl-X or (ph) m -X; R2is selected from H, Y, C 1~6 alkyl-Y or (ph) n -Y; X and Y are each independently selected from F, Cl, Br or I, and m and n are integers from 1 to 3. R3is selected from .

2. The photoresist of claim 1, wherein R1is selected from X, C 1~6 alkyl-X or (ph) m -X; R2is selected from H, Y, C 1~6 alkyl-Y or (ph) n -Y.

3. The photoresist of claim 2, wherein R2is selected from H, Y or C 1~6 alkyl-Y.

4. The photoresist of claim 3, wherein R1is selected from X or C 1~6 alkyl-X.

5. A photoresist, characterized by, The photoresist comprises 10wt%-30wt% phenolic resin, 2wt%-10wt% diazonaphthoquinone photosensitizer and 0.1wt%-10wt% additive. The structural formula of the additive is as follows: 。 6. The photoresist according to any one of claims 1 to 5, wherein The molecular weight of the phenolic resin is 4000-10000.

7. The photoresist of claim 6, wherein The structural formula of the phenolic resin is as follows: a, b and c are each independently 0, but not at the same time.

8. The photoresist according to any one of claims 1 to 5, wherein The diazonaphthoquinone photosensitizer comprises 2,1,4 type diazonaphthoquinone photosensitizer and / or 2,1,5 type diazonaphthoquinone photosensitizer.

9. The photoresist according to any one of claims 1 to 5, wherein The photoresist further comprises 0.1wt%-5wt% leveling agent.

10. The photoresist of claim 9, wherein The leveling agent comprises any one or more of silicone leveling agent, polyether leveling agent and fluorine-containing polymethyl methacrylate leveling agent.

11. The photoresist of claim 10, wherein The leveling agent is silicone leveling agent.

12. The photoresist according to any one of claims 1 to 5, wherein The photoresist further comprises 40wt%-80wt% solvent.

13. The photoresist of claim 12, wherein The solvent comprises any one or more of propylene glycol methyl ether acetate, 2-heptanone and ethyl lactate.

14. The photoresist of any one of claims 1 to 5, wherein The photoresist comprises 20wt%-30wt% phenolic resin, 5wt%-8wt% diazonaphthoquinone photosensitizer, 0.1wt%-2wt% leveling agent, 40wt%-80wt% solvent and 0.1wt%-3wt% additive.

15. Use of the photoresist according to any one of claims 1-14 in integrated circuits and chip packaging.

16. Use of the photoresist according to claim 15 in integrated circuits and chip packaging, characterized in that, The thickness of the photoresist is 7μm-20μm.

17. Use of the photoresist according to claim 15 in integrated circuits and chip packaging, characterized in that, The developing solution for the photoresist is potassium hydroxide solution.

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