Ultrahigh-sensitivity low-temperature photoresist composition, preparation method and application

Abstract

The invention provides an ultrahigh-sensitivity low-temperature photoresist composition as well as a preparation method and application thereof, and relates to the technical field of photoresist. The ultrahigh-sensitivity low-temperature photoresist composition provided by the invention comprises phenolic resin, a photosensitive compound, an adhesive force increasing agent, a surface leveling agent and a solvent, the ultrahigh-sensitivity low-temperature photoresist composition comprises the following components in percentage by mass: 5-15% of phenolic resin, 2-8% of a photosensitive compound and 80-90% of a solvent, based on the total weight of the ultrahigh-sensitivity low-temperature photoresist composition, the content of the adhesive force increasing agent is 0.1-0.8 wt%, and the content of the surface leveling agent is 0.8-1.5 wt%; the photosensitive composition contains various types of photosensitive compounds, a polymethoxy-containing additive, a sensitivity accelerant and various solvents. The photoresist composition provided by the invention can meet the use requirements of an OLED (Organic Light Emitting Diode) low-temperature process, and is suitable for manufacturing of OLED panel low-temperature process layers.

Description

Technical Field

[0001] The present invention relates to the technical field of photoresists, and particularly to an ultra-high sensitivity low-temperature photoresist composition, a preparation method and an application thereof. Background Art

[0002] With the booming development of new infrastructure such as cloud computing, Internet of Things, 5G communication, artificial intelligence, etc., integrated circuits, as one of the core industries of the information industry, have also embarked on a path of high-speed development. Photoresist is a key material required for the production of integrated circuits. A photoresist (also known as a photoresist) is an etch-resistant thin film material whose solubility changes upon irradiation or radiation by light sources such as ultraviolet light, excimer laser, electron beam, ion beam, X-ray, etc. It has the characteristics of rapid curing, time saving and low solvent release, and is mainly used for the fine pattern processing of integrated circuits and semiconductor discrete devices. In recent years, it has gradually been applied to the production of displays in the optoelectronic field, such as OLED panels, etc.

[0003] Due to the photochemical sensitivity of the photoresist, its photochemical reaction can be utilized. Through processes such as exposure and development, the required fine pattern is copied from the mask plate to the substrate to be processed, and then processes such as etching, diffusion, and ion implantation are carried out. Therefore, photoresist has become a key basic material for microfabrication technology in the optoelectronic information industry. Currently, typical resins for photoresists include phenolic resins, PHS, acrylics, and polyimides. Considering economic and efficiency factors, phenolic resins are widely used, and they can be thinly, evenly, and quickly coated on the substrate. Currently, phenolic resins include novolak resins, phenolic epoxy resins, linear phenolic resins, and resol resins, which generally have poor sensitivity and etching performance and are difficult to meet the requirements of high-performance photoresists.

[0004] Up to now, researchers in related fields have been trying to improve the photoresist composition in order to form a photoresist film with effectively improved coating uniformity, photosensitivity, development contrast, resolution, adhesion to the substrate, residual film rate, etc., but the effect is not obvious.

[0005] Chinese Patent CN112684661A discloses a photoresist composition and a preparation method thereof, including: a phenolic resin, a diazo-based photosensitive compound, and an organic solvent; wherein, the phenolic resin includes a linear phenolic resin and a silica-modified phenolic resin. Phenolic resin, diazo-based photosensitive compound and organic solvent. In the photoresist composition of the present invention, by improving the heat resistance and adhesion of the film-forming resin, the adhesion is good, the residual film rate is above 99%, and the heat resistance temperature is above 150°C, but its sensitivity and the angle of forming a pattern are not involved.

[0006] Chinese Patent CN115793391A discloses a photoresist, which comprises: 10wt%-30wt% phenolic resin, 2wt%-10wt% diazonaphthoquinone photosensitizer, and 0.1wt%-10wt% additive; the photosensitivity value of the obtained photoresist is 215-250 mj / cm 2 ; however, the residual film rate is not involved; but in the prior art, improving the photosensitivity of the photosensitive adhesive usually results in a decrease in the residual film rate.

[0007] Based on this, developing a photoresist with high photosensitivity and a high residual film rate is the research focus of researchers in this field. Summary of the Invention

[0008] In view of the above problems, the present invention provides an ultra-high sensitivity low-temperature photoresist composition. By optimizing the components, it is found that the prepared photoresist has ultra-high photosensitivity and a relatively high residual film rate.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0010] On the one hand, the present invention provides an ultra-high sensitivity low-temperature photoresist composition, which comprises phenolic resin, a photosensitive compound, an adhesion enhancer, a surface leveling agent, and a solvent; in the ultra-high sensitivity low-temperature photoresist composition, the mass percentages of the components are: phenolic resin 5-15%, photosensitive compound 2%-8%, solvent 80%-90%; based on the total weight of the ultra-high sensitivity low-temperature photoresist composition, the content of the adhesion enhancer is 0.1-0.8wt%, and the content of the surface leveling agent is 0.8-1.5wt%;

[0011] The phenolic resin is a linear phenolic resin, and its structure is as shown in (1), where the m / n ratio is 4 / 6 - 6 / 4;

[0012]

[0013] The photosensitive composition comprises an I-line photosensitive compound and / or a G-line photosensitive compound;

[0014] The I-line photosensitive compound is a compound shown in structural formulas (4) and (5);

[0015]

[0016] Among them, R8, R 10 and R 11 each independently selects a structure of 2-diazo-1-naphthol-5-sulfonyl as shown in formula (6), and R9 is selected from a hydrogen group;

[0017]

[0018] Among them, R12 and R 13 Both are independently selected from the structure 2-diazo-1-naphthol-5-sulfonyl as shown in Formula (6), and R 14 is selected from the structure 2-diazo-1-naphthol-5-sulfonyl or a hydrogen group as shown in Formula (6).

[0019]

[0020] Preferably, m = 2 - 50; n = 2 - 50.

[0021] Preferably, the phenolic resin is a phenolic resin synthesized from m-cresol, p-cresol and formaldehyde, and the ratio of m-cresol to p-cresol is 48 - 52:50 - 55; further preferably, the ratio of m-cresol to p-cresol is 48 - 50:50 - 55; more preferably, the ratio of m-cresol to p-cresol is 50:50.

[0022] Preferably, the molecular weight of the phenolic resin is 3000 - 8000, and the molecular weight distribution is 4 - 8;

[0023] Preferably, the G-line photosensitive compound is the compound shown in Structural Formulas (2) and (3);

[0024]

[0025] Among them, R1, R3 and R4 are each independently selected from the structure 2-diazo-1-naphthol-5-sulfonyl as shown in Formula (6), and R2 is selected from a hydrogen group.

[0026]

[0027] R5 and R7 are each independently selected from the structure 2-diazo-1-naphthol-5-sulfonyl as shown in Formula (6), and R6 is selected from a hydrogen group.

[0028] Preferably, the adhesion promoter is a melamine resin with the structural formula (7); the adhesion promoter can enhance the adhesion between the ultra-high sensitivity low-temperature photoresist composition and the substrate.

[0029]

[0030] Preferably, the surface leveling agent is selected from at least one of polycyclomethylsiloxane, polydimethylsiloxane and polymethylhydrosiloxane. The surfactant can reduce Mura generated during the coating process.

[0031] Preferably, the solvent is selected from at least one of ethylene glycol methyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol methyl ether acetate, methyl acetate, n-butyl acetate, ethyl propionate, ethyl lactate, ethyl acetate, n-butyl acetate, methanol, benzyl alcohol, diphenylmethanol, triphenylmethanol, isopropanol, isobutanol, isoamyl alcohol, ethylene glycol, propylene glycol, glycerol, butanol, octanol, vinyl alcohol, and allyl alcohol.

[0032] On the other hand, the present invention provides a method for preparing the above-mentioned ultra-high sensitivity low-temperature photoresist composition, comprising the following steps: mixing each component.

[0033] On yet another aspect, the present invention provides the application of the above-mentioned ultra-high sensitivity low-temperature photoresist composition in the manufacture of the low-temperature process layer of an OLED panel.

[0034] Preferably, the temperature of the low-temperature process is 75 - 85 °C.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) Through the coordinated cooperation of each component, the photoresist composition of the present invention has the characteristics of ultra-high sensitivity, high residual film rate, good pattern angle, and high development adhesion, and is suitable for the manufacture of the low-temperature process layer of an OLED panel.

[0037] (2) The preparation method of the photoresist composition of the present invention is simple and feasible, and a photoresist composition with the characteristics of ultra-high sensitivity, high residual film rate, good pattern angle, and high development adhesion can be prepared. Description of the Drawings

[0038] Figure 1 It is a resolution test result diagram of Example 1. Detailed Embodiments

[0039] In order to make the technical means, creative features, achieved purposes, and effects of the present invention easy to understand, the present invention will be further clarified below with reference to specific embodiments. However, the following embodiments are only the preferred embodiments of the present invention and not all of them. Based on the embodiments in the embodiments, other embodiments obtained by those skilled in the art without creative efforts all belong to the protection scope of the present invention. It is worth noting that the raw materials used in the present invention are all ordinary commercially available products, and no specific limitation is made on their sources. The technical and scientific terms used in the embodiments have the same meanings as those commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0040] The surface leveling agent and solvent used in the examples and comparative examples:

[0041] The surface leveling agent is selected from at least one of polycyclomethylsiloxane, polydimethylsiloxane, and polymethylhydrosiloxane.

[0042] The solvent is selected from at least one of ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol methyl ether acetate, methyl acetate, n-butyl acetate, ethyl propionate, ethyl lactate, ethyl acetate, n-butyl acetate, methanol, benzyl alcohol, diphenylmethanol, triphenylmethanol, isopropanol, isobutanol, isopentanol, ethylene glycol, propylene glycol, glycerol, butanol, octanol, vinyl alcohol, and allyl alcohol.

[0043] Example 1

[0044] An ultra-high sensitivity low-temperature photoresist composition consists of the following components:

[0045] 9.75 g of phenolic resin, 2.25 g of photosensitive compound, 88 g of solvent. Based on the total weight of the photoresist composition, the content of the surface leveling agent is 0.5 wt%, and the adhesion enhancer is 1.2 wt%.

[0046] The phenolic resin structure is a phenolic resin (1) synthesized from m-cresol, p-cresol, and formaldehyde, where the ratio of m-cresol to p-cresol is 50 / 50; where m = 2 - 50; n = 2 - 50.

[0047]

[0048] There are two photosensitive compounds, 1.125 g of the photosensitive compound shown in structural formula (3) and 1.125 g of the photosensitive compound shown in structural formula (4);

[0049] The preparation method is: mixing all components evenly.

[0050] Example 2

[0051] An ultra-high sensitivity low-temperature photoresist composition, the difference from Example 1 is only in the photosensitive compound:

[0052] Two photosensitive compounds are used, 1.80 g of the photosensitive compound shown in structural formula (2) and 0.45 g of the photosensitive compound shown in structural formula (4), and other conditions are the same as in Example 1.

[0053] Example 3

[0054] An ultra-high sensitivity low-temperature photoresist composition, the difference from Example 1 is only in the photosensitive compound:

[0055] Two photosensitive compounds are used, 0.45 g of the photosensitive compound shown in structural formula (3) and 1.80 g of the photosensitive compound shown in structural formula (4), and other conditions are the same as in Example 1.

[0056] Example 4

[0057] An ultra-high sensitivity low-temperature photoresist composition, which is only different from Example 1 in that the photosensitive compounds are different:

[0058] Two photosensitive compounds are used, including 0.45 g of the photosensitive compound shown in Structural Formula (2) and 1.80 g of the photosensitive compound shown in Structural Formula (4), and other conditions are the same as in Example 1.

[0059] Example 5

[0060] An ultra-high sensitivity low-temperature photoresist composition, which is only different from Example 1 in that the photosensitive compounds are different:

[0061] Two photosensitive compounds are used, including 1.125 g of the photosensitive compound shown in Structural Formula (2) and 1.125 g of the photosensitive compound shown in Structural Formula (4), and other conditions are the same as in Example 1.

[0062] Example 6

[0063] An ultra-high sensitivity low-temperature photoresist composition, which is only different from Example 1 in that the photosensitive compounds are different:

[0064] Two photosensitive compounds are used, including 1.80 g of the photosensitive compound shown in Structural Formula (4) and 0.45 g of the photosensitive compound shown in Structural Formula (5), and other conditions are the same as in Example 1.

[0065] Example 7

[0066] An ultra-high sensitivity low-temperature photoresist composition, which is only different from Example 1 in that the photosensitive compounds are different:

[0067] One photosensitive compound is used, including 2.25 g of the photosensitive compound shown in Structural Formula (4), and other conditions are the same as in Example 1.

[0068] Comparative Example 1

[0069] An ultra-high sensitivity low-temperature photoresist composition, which is only different from Example 1 in that the photosensitive compounds are different:

[0070] Two photosensitive compounds are used, including 0.45 g of the photosensitive compound shown in Structural Formula (2) and 1.80 g of the photosensitive compound shown in Structural Formula (3), and other conditions are the same as in Example 1.

[0071] Comparative Example 2

[0072] An ultra-high sensitivity low-temperature photoresist composition, which is only different from Example 1 in that the photosensitive compounds are different:

[0073] Two photosensitive compounds were used, including 1.125 g of the photosensitive compound shown in Structural Formula (2) and 1.125 g of the photosensitive compound shown in Structural Formula (3). Other conditions were the same as in Example 1.

[0074] Comparative Example 3

[0075] An ultra-high sensitivity low-temperature photoresist composition, which is different from Example 1 only in the photosensitive compound:

[0076] Two photosensitive compounds were used, including 1.80 g of the photosensitive compound shown in Structural Formula (2) and 0.45 g of the photosensitive compound shown in Structural Formula (3). Other conditions were the same as in Example 1.

[0077] Comparative Example 4

[0078] An ultra-high sensitivity low-temperature photoresist composition, which is different from Example 1 only in the photosensitive compound:

[0079] One photosensitive compound was used, including 2.25 g of the photosensitive compound shown in Structural Formula (2). Other conditions were the same as in Example 1.

[0080] Comparative Example 5

[0081] An ultra-high sensitivity low-temperature photoresist composition, which is different from Example 1 only in the photosensitive compound:

[0082] One photosensitive compound was used, including 2.25 g of the photosensitive compound shown in Structural Formula (3). Other conditions were the same as in Example 1.

[0083] The photosensitive compounds used in Examples 1-7 and Comparative Examples 1-5 are shown in Table 1 below:

[0084] Table 1. Photosensitive Compounds Used in Examples 1-7 and Comparative Examples 1-5

[0085]

[0086] Test Example 1

[0087] Sensitivity evaluation of the photoresists prepared in Examples 1-7 and Comparative Examples 1-5:

[0088] The photoresist composition was spin-coated on a silicon wafer, vacuum-dried in a vacuum drying oven (VCD), baked on a hot plate at 80 °C for 120 s to form a hard film of the photoresist composition, and the film thickness was measured to be about 1.5 μm by a film thickness gauge; then, the photoresist layer was exposed with different energies using a Broadband exposure machine, developed for 70 s with 2.38 wt% tetramethylammonium hydroxide (TMAH) after exposure, washed with water for 25 s, and then dried. The exposed part of the photoresist composition was removed to form a photoresist pattern. Record the energy at which the exposure and development are just complete, and calculate the sensitivity of the photoresist composition. The smaller the exposure energy, the more beneficial it is to improve production capacity. The results are shown in Table 2.

[0089] Test Example 2

[0090] Angle evaluation of the photoresists prepared in Examples 1-7 and Comparative Examples 1-5:

[0091] After the photoresist composition forms a pattern on the silicon wafer, the photoresist composition pattern was inspected using a scanning electron microscope. Taking a 3-μm line as the standard, its line angle was measured. The results are shown in Table 2.

[0092] Test Example 3

[0093] Residual film rate evaluation of the photoresists prepared in Examples 1-7 and Comparative Examples 1-5:

[0094] The photoresist composition was spin-coated on a silicon wafer, vacuum-dried in a vacuum drying oven (VCD), baked on a hot plate at 80 °C for 120 s to form a hard film of the photoresist composition; then developed for 70 s with 2.38 wt% tetramethylammonium hydroxide (TMAH), washed with water for 25 s, and then dried. The thickness of the hard film before development and the remaining hard film thickness after 70 s of development were measured by a film thickness gauge, and the percentage of the hard film thickness after development to the hard film thickness before development is the residual film rate. The results are shown in Table 2.

[0095] Table 2. Evaluation of the photoresist

[0096] Sensitivity (mj) Angle (°) Residual film rate (%) Example 1 49 60 91 Example 2 70 67 91 Example 3 60 77 93 Example 4 66 83 94 Example 5 68 75 93 Example 6 85 90 95 Example 7 65 89 95 Comparative Example 1 46 37 84 Comparative Example 2 56 46 86 Comparative Example 3 65 55 89 Comparative Example 4 71 62 89 Comparative Example 5 41 33 83

[0097] It can be seen from Table 2 that compared with Comparative Examples 1-5, the photoresists prepared in Examples 1-7 not only have high sensitivity but also have excellent residual film rates.

[0098] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the protection scope of the present invention. Any simple modification or equivalent replacement of the technical solution of the present invention by those of ordinary skill in the art shall not depart from the essence and scope of the technical solution of the present invention.

Claims

1. An ultra-high sensitivity low-temperature photoresist composition, characterized in that, It contains phenolic resin, photosensitive compound, adhesion enhancer, surface leveling agent and solvent; in the ultra-high sensitivity low-temperature photoresist composition, the mass percentages of each component are: phenolic resin 5-15%, photosensitive compound 2%-8%, solvent 80%-90%; based on the total weight of the ultra-high sensitivity low-temperature photoresist composition, the content of the adhesion enhancer is 0.1-0.8 wt%, and the content of the surface leveling agent is 0.8-1.5 wt%. The phenolic resin is a linear phenolic resin, and its structure is as shown in (1), where the m / n ratio is 4 / 6 - 6 / 4; The photosensitive composition contains I-line photosensitive compound and / or G-line photosensitive compound; The I-line photosensitive compound is the compound shown in structural formulas (4) and (5); Among them, R8, R 10 and R 11 The three are each independently selected from the structure 2-diazo-1-naphthol-5-sulfonyl as shown in formula (6), and R9 is selected from hydrogen; Among them, R 12 and R 13 each independently selects a 2-diazo-1-naphthol-5-sulfonyl group having a structure as shown in Formula (6), and R 14 selects a 2-diazo-1-naphthol-5-sulfonyl group having a structure as shown in Formula (6) or a hydrogen group; 2. The ultra-high sensitivity low-temperature photoresist composition according to claim 1, characterized in that, The phenolic resin is a phenolic resin synthesized from m-cresol, p-cresol and formaldehyde, and the ratio of m-cresol to p-cresol is 48-52:50-55.

3. The ultra-high sensitivity cryogenic photoresist composition according to claim 1, wherein The molecular weight of the phenolic resin is 3000-8000, and the molecular weight distribution is 4-8.

4. The ultra-high sensitivity low-temperature photoresist composition according to claim 1, wherein The G-line photosensitive compound is the compound shown in structural formulas (2) and (3); Among them, R1, R3 and R4 each independently select the structure 2-diazo-1-naphthol-5-sulfonyl as shown in formula (6), and R2 is selected from a hydrogen group; Both R5 and R7 independently select the structure 2-diazo-1-naphthol-5-sulfonyl as shown in formula (6), and R6 is selected from a hydrogen group.

5. The ultra-high sensitivity low-temperature photoresist composition according to claim 1, wherein The adhesion enhancer is a melamine resin, and its structural formula is (7); 6. The ultra-high sensitivity low-temperature photoresist composition according to claim 1, wherein The surface leveling agent is selected from at least one of polycyclomethylsiloxane, polydimethylsiloxane and polymethylhydrosiloxane.

7. The ultra-high sensitivity low-temperature photoresist composition according to claim 1, wherein The solvent is selected from at least one of ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol methyl ether acetate, methyl acetate, n-butyl acetate, ethyl propionate, ethyl lactate, ethyl acetate, n-butyl acetate, methanol, benzyl alcohol, diphenylmethanol, triphenylmethanol, isopropanol, isobutanol, isopentanol, ethylene glycol, propylene glycol, glycerol, butanol, octanol, vinyl alcohol and allyl alcohol.

8. A method for preparing the ultra-high sensitivity low-temperature photoresist composition according to any one of claims 1-7, characterized in that, It includes the following steps: mixing each component.

9. Application of the ultra-high sensitivity low-temperature photoresist composition according to any one of claims 1-7 in the manufacture of the low-temperature process layer of an OLED panel.

10. The application according to claim 9, wherein The temperature of the low-temperature process is 75-85 °C.

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