Positive photoresist composition, preparation method thereof, and application

Abstract

The present invention provides a positive photoresist composition, a preparation method thereof, and an application, relating to the technical field of photoresist preparation, which includes: phenolic resin, crosslinking agent, acidic catalyst, photo deactivator, and optionally a solvent, wherein the photo deactivator includes an anionic initiator. The positive photoresist composition of the present invention belongs to a chemically amplified photoresist. The phenolic resin therein has excellent physical and chemical properties, appropriate dissolution rate, and good film-forming property. In the non-exposed area, the acidic catalyst catalyzes the crosslinking reaction between the crosslinking agent and the phenolic resin. After exposure to ultraviolet light with a wavelength of 365 nm or 436 nm in the exposed area, the compound generated by the anionic initiator will deactivate the acidic catalyst and no longer catalyze the crosslinking reaction. The present invention solves the technical problem that the poor photosensitivity of the photoresist leads to a large demand for exposure dose, and achieves the technical effects of strong photosensitivity of the photoresist, small demand for exposure dose, improved production efficiency, and reduced production cost.

Description

Technical Field

[0001] The present invention relates to the technical field of photoresist preparation, and particularly to a positive photoresist composition, a preparation method thereof, and an application thereof. Background Art

[0002] Currently, positive photoresists based on phenolic resins are widely used in the field of lithography at 365 nm or 436 nm in the market. For example, in the fields of LED chip manufacturing and liquid crystal display screens, the consumption of phenolic positive photoresists is particularly large.

[0003] Traditional phenolic positive photoresists generally include the following components: phenolic resin, photosensitizer, solvent, and additives, etc. The most common photosensitizer (PAC) among them is diazonaphthoquinone (DNQ). Such compounds are dissolution inhibitors in the absence of exposure, and become dissolution promoters after exposure to ultraviolet light at 365 nm or 436 nm, thus forming a positive photoresist image. However, this type of system is a non-chemically amplified photoresist, and the photosensitivity of diazonaphthoquinone (DNQ) is poor. Therefore, a large amount of light energy is required for the complete transformation of the DNQ structure from dissolution inhibition to dissolution promotion. Taking a 3-micron photoresist thickness as an example, the exposure dose is at least required to be above 60 mJ / cm 2 above, which severely limits the application scope of this type of photoresist and also reduces the production efficiency.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a positive photoresist composition, which has the characteristics of strong photosensitivity, requires a small exposure dose, can improve production efficiency, and reduce production costs.

[0006] Another purpose of the present invention is to provide a preparation method for the above positive photoresist composition, which has a simple process and a high excellent rate.

[0007] The third purpose of the present invention is to provide an application of the above positive photoresist composition in integrated circuit manufacturing.

[0008] In order to achieve the above purposes of the present invention, the following technical solutions are specifically adopted:

[0009] In the first aspect, the present invention provides a positive photoresist composition, which includes the following components:

[0010] Phenolic resin, crosslinking agent, acidic catalyst, photo-deactivator, and optionally solvent;

[0011] The phenolic resin includes a compound represented by the general formula (1);

[0012]

[0013] The molecular weight Mw of the phenolic resin is 1,000 - 10,000;

[0014] The photo deactivator includes an anionic initiator.

[0015] Furthermore, the crosslinking agent includes at least one of melamine, melamine derivatives, melamine phosphate, melamine derivative modified polyurethane, and benzoguanamine.

[0016] Furthermore, the acidic catalyst is at least one of organic acids and inorganic acids;

[0017] More preferably, the organic acids include at least one of formic acid, acetic acid, propionic acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, and p-toluenesulfonic acid;

[0018] More preferably, the inorganic acids include at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and hydrofluoric acid.

[0019] Furthermore, the anionic initiator includes acetophenone O-benzoyl oxime.

[0020] Furthermore, the solvent includes at least one of propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl acetate, and ethyl lactate.

[0021] Furthermore, the positive photoresist composition includes the following components by weight parts:

[0022] 10 - 60 parts of phenolic resin, 2 - 20 parts of crosslinking agent, 0.2 - 5 parts of acidic catalyst, 0.2 - 5 parts of anionic initiator, and 10 - 100 parts of solvent.

[0023] Furthermore, the positive photoresist composition includes the following components by weight parts:

[0024] 50 parts of phenolic resin, 5 parts of benzoguanamine, 0.5 part of ethanesulfonic acid, 4 parts of acetophenone O-benzoyl oxime, and 100 parts of propylene glycol monomethyl ether acetate.

[0025] In a second aspect, the present invention provides a method for preparing the above positive photoresist composition, including the following steps:

[0026] The solvent dissolves each component to obtain the positive photoresist composition.

[0027] Furthermore, after dissolution, a filtration step is further included;

[0028] More preferably, the filtration includes filtration using a filter membrane;

[0029] More preferably, the pore size of the filter membrane is 0.01 - 1 micrometer.

[0030] In a third aspect, the present invention provides an application of the above positive photoresist composition in integrated circuit manufacturing.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] The positive photoresist composition provided by the present invention belongs to a chemically amplified photoresist and has the characteristic of strong photosensitivity. Therefore, the exposure dose requirement is small, which can improve production efficiency and reduce production costs. Specifically, the phenolic resin therein has excellent physical and chemical properties, a suitable dissolution rate, and good film-forming properties due to its specific structure. In the non-exposed area, the acidic catalyst catalyzes the crosslinking reaction between the crosslinking agent and the phenolic resin, so that it is insoluble in the alkaline developer. After being exposed to ultraviolet light with a wavelength of 365 nm or 436 nm in the exposed area, the compound generated by the anionic initiator will inactivate the acidic catalyst and no longer catalyze the crosslinking reaction. After being developed with the alkaline developer, a positive image is formed.

[0033] The preparation method of the above positive photoresist composition provided by the present invention has a simple process and a high excellent rate. Detailed embodiments

[0034] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] According to the first aspect of the present invention, a positive photoresist composition is provided, which comprises the following components:

[0036] Phenolic resin, crosslinking agent, acidic catalyst, photo-deactivator, and optionally a solvent;

[0037] In the present invention, the phenolic resin comprises a compound represented by the general formula (1);

[0038]

[0039] The molecular weight Mw of the phenolic resin selected in the present invention is 1000 - 10000. Its typical but non-limiting molecular weight Mw is, for example, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 10000. The molecular weight of the phenolic resin selected in the present invention can enable the photoresist composition to exhibit an excellent development effect.

[0040] In the present invention, a photo-deactivator refers to a compound that can be photosensitive at 365 nm or 436 nm and deactivate an acidic catalyst. The photo-deactivator includes, but is not limited to, anionic initiators.

[0041] The present invention provides a phenolic positive photoresist composition based on a deactivation mechanism, belonging to chemically amplified photoresists. It has strong photosensitivity, can greatly improve the production efficiency of customers, and reduce production costs. Specifically, a phenolic resin with a specific structure is selected as the main resin in the present invention, which has excellent physical and chemical properties, a suitable dissolution rate, and good film-forming properties. In the non-exposed area, the acidic catalyst catalyzes the crosslinking reaction between the crosslinking agent and the phenolic resin, so that it is insoluble in the alkaline developer. After exposure to ultraviolet light with a wavelength of 365 nm or 436 nm in the exposed area, the compound generated by the anionic initiator will deactivate the acidic catalyst and no longer catalyze the crosslinking reaction. After being developed with the alkaline developer, a positive image is formed.

[0042] Traditional phenolic positive photoresists are used for 365 nm or 436 nm exposure. Due to the poor photosensitivity of their photosensitizer DNQ, the required exposure dose is large, which severely limits their application range and greatly reduces the production efficiency. Taking a 3-micron photoresist thickness as an example, its exposure dose is at least 60 mJ / cm 2 Above; while the positive photoresist composition based on the deactivation mechanism of the present invention solves the problem of large required exposure dose caused by the poor photosensitivity of traditional phenolic positive photoresists. Taking a 3-micron film thickness as an example, the exposure dose is 30 mj / cm 2 Below, greatly improving the production efficiency.

[0043] In a preferred embodiment, the crosslinking agent of the present invention includes, but is not limited to, at least one of melamine, melamine derivatives, melamine phosphate, melamine derivative-modified polyurethane, and benzoguanamine.

[0044] In a preferred embodiment, the acidic catalyst of the present invention is at least one of organic acids and inorganic acids. Among them, the organic acids include, but are not limited to, at least one of formic acid, acetic acid, propionic acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, and p-toluenesulfonic acid, and the inorganic acids include, but are not limited to, at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and hydrofluoric acid.

[0045] In a preferred embodiment, the anionic initiator of the present invention includes, but is not limited to, acetophenone O-benzoyl oxime.

[0046] The preferred crosslinking agent, acidic catalyst and anionic initiator of the present invention are such that, in the non-exposed area, the preferred acidic catalyst can better catalyze the crosslinking reaction between the crosslinking agent and the phenolic resin, thereby making it insoluble in the alkaline developer. However, after the exposed area is exposed to ultraviolet light of 365nm or 436nm wavelength, the compound produced by the preferred anionic initiator can better deactivate the acidic catalyst and no longer catalyze the crosslinking reaction. After development with an alkaline developer, a positive image is formed, thereby obtaining a better development effect.

[0047] In a preferred embodiment, the solvent of the present invention includes but is not limited to at least one of propylene glycol methyl ether, propylene glycol methyl ether acetate, ethyl acetate and ethyl lactate.

[0048] The preferred solvent of the present invention can fully dissolve the above components, thereby further enhancing the developing effect of the photoresist composition.

[0049] In a preferred embodiment, the positive photoresist composition of the present invention comprises the following components in parts by weight:

[0050] 10-60 parts of phenolic resin, 2-20 parts of cross-linking agent, 0.2-5 parts of acidic catalyst, 0.2-5 parts of anionic initiator and 10-100 parts of solvent.

[0051] Among them, typical but non-limiting weight amounts of phenolic resin are, for example, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, and 60 parts; typical but non-limiting weight amounts of cross-linking agent are, for example, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, and 20 parts; typical but non-limiting weight amounts of acidic catalyst are, for example, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, Typical but non-limiting weight amounts of anionic initiators are, for example, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.4, 4.6, 4.8, 5 parts; typical but non-limiting weight amounts of solvents are, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 parts.

[0052] In a preferred embodiment, the positive photoresist composition of the present invention comprises the following components in parts by weight:

[0053] 50 parts of phenolic resin, 5 parts of benzoguanamine, 0.5 parts of ethanesulfonic acid, 4 parts of acetophenone O-benzoyl oxime and 100 parts of propylene glycol methyl ether acetate.

[0054] The preferred weight ratio of each component in the present invention can enable the positive photoresist composition to achieve better development effect, and the required exposure dose is small, thereby improving production efficiency and reducing production costs.

[0055] According to a second aspect of the present invention, there is provided a method for preparing the above-mentioned positive photoresist composition, comprising the following steps:

[0056] The components are dissolved in a solvent to obtain a positive photoresist composition.

[0057] In a preferred embodiment, the present invention further comprises filtration after dissolving.

[0058] The present invention utilizes a solvent to dissolve the components, and then filters to obtain a positive photoresist composition; wherein, filtering includes but is not limited to filtering using a filter membrane, the pore size of the filter membrane is 0.01-1 micron, and its typical but non-limiting pore size is, for example, 0.01 micron, 0.02 micron, 0.05 micron, 0.1 micron, 0.2 micron, 0.5 micron, and 1 micron.

[0059] The preparation method of the positive photoresist composition provided by the present invention has simple process and high quality rate.

[0060] According to a third aspect of the present invention, there is provided a use of the positive photoresist composition in the manufacture of integrated circuits.

[0061] The application provided by the present invention can better manufacture integrated circuits, which can not only reduce process costs but also improve production efficiency.

[0062] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples were prepared according to existing methods or directly purchased from the market.

[0063] Example 1

[0064] The weight ratio of the components of the positive photoresist composition of this embodiment is as follows: After mixing the components, they are fully dissolved in a solvent of propylene glycol methyl ether acetate, and then filtered through a filter membrane with a pore size of 0.2 microns to obtain a positive photoresist composition. The structure of the phenolic resin of this embodiment is: Mw is 3000.

[0065]

[0066]

[0067] Example 2

[0068] The component weight ratios of the positive photoresist composition in this example are as follows: After mixing each component, it is fully dissolved with the solvent propylene glycol monomethyl ether acetate, and then filtered through a filter membrane with a pore size of 0.2 microns to obtain the positive photoresist composition. Among them, the structure of the phenolic resin in this example is: Mw is 3000.

[0069] Phenolic resin 50g Phenylmelamine 5g Ethanesulfonic acid 0.5g Acetophenone O-benzoyl oxime 1g Propylene glycol methyl ether acetate 100g

[0070] Example 3

[0071] The component weight ratios of the positive photoresist composition in this example are as follows: After mixing each component, it is fully dissolved with the solvent propylene glycol monomethyl ether, and then filtered through a filter membrane with a pore size of 0.2 microns to obtain the positive photoresist composition. Among them, the structure of the phenolic resin in this example is: Mw is 3000.

[0072] Phenolic resin 50g Melamine 3g Sulfuric acid 0.5g Acetophenone O-benzoyl oxime 0.5g Propylene glycol methyl ether 100g

[0073] Example 4

[0074] The difference between this example and Example 1 is that Mw in this example is 2000, and the rest are the same as in Example 1, obtaining a positive photoresist composition.

[0075] Example 5

[0076] The difference between this example and Example 2 is that Mw in this example is 5000, and the rest are the same as in Example 2, obtaining a positive photoresist composition.

[0077] Example 6

[0078] The difference between this example and Example 1 is that the amount of acetophenone O-benzoyl oxime in this example is 3 g, and the rest are the same as in Example 1, obtaining a positive photoresist composition.

[0079] Example 7

[0080] The difference between this example and Example 2 is that the amount of acetophenone O-benzoyl oxime in this example is 4 g, and the rest are the same as in Example 2, obtaining a positive photoresist composition.

[0081] Comparative Example 1

[0082] Startech product non-chemically amplified positive photoresist SUN-110P.

[0083] Experimental Example 1

[0084] The positive photoresist compositions of Examples 1-7 and the positive photoresist SUN-110P of Comparative Example 1 were spin-coated on the treated substrates respectively. Then, pre-baking (PAB) was carried out on a hot plate at 100 °C for 60 s. The rotation speed was adjusted to make the film thickness after drying 3 μm. After exposure through a mask plate (the pattern size was 10-μm lines) by an exposure machine at 365 nm, post-exposure baking (PEB) was carried out on a hot plate at 130 °C for 60 s. Then, it was immersed and developed in 2.38 wt% TMAH for 60 s, and then washed with deionized water to complete the photolithography process, obtaining a positive image. The width of the lines in the image was measured. When the line width was 10 μm (the same as the mask plate size), the exposure dose was recorded, and the data are shown in Table 1.

[0085] Table 1

[0086] Sample <![CDATA[Exposure dose (mJ / cm 2 )]]> Example 1 25 Example 2 22 Example 3 26 Example 4 20 Example 5 29 Example 6 18 Example 7 15 Comparative Example 1 70

[0087] Experimental Example 2

[0088] The difference between the photolithography process of this experimental example and that of Experimental Example 1 was that this experimental example used exposure at a wavelength of 436 nm, and the remaining steps were the same as those of Experimental Example 1. When the photolithography pattern size was the same as the mask plate size (both were 10 μm), the exposure dose was recorded, and the data are shown in Table 2.

[0089] Table 2

[0090]

[0091]

[0092] Thus, it can be seen that the phenolic positive photoresist composition based on the deactivation mechanism provided by the present invention has the characteristic of strong photosensitivity. Taking a 3-μm thick photoresist as an example, its exposure dose is 30 mj / cm 2 Therefore, it can greatly improve the production efficiency of customers and reduce the production cost.

[0093] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A positive photoresist composition, characterized in that, It comprises the following components: Phenolic resin, crosslinking agent, acidic catalyst, photo deactivator and optionally solvent; The phenolic resin comprises a compound represented by general formula (1); （1） The molecular weight Mw of the phenolic resin is 1000 - 10000; The photo deactivator comprises an anionic initiator; The crosslinking agent comprises at least one of melamine, melamine phosphate, melamine derivative modified polyurethane and benzoguanamine; The acidic catalyst is at least one of organic acid and inorganic acid; The organic acid comprises at least one of formic acid, acetic acid, propionic acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid and p-toluenesulfonic acid; The inorganic acid comprises at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and hydrofluoric acid; The anionic initiator comprises acetophenone O-benzoyl oxime.

2. The positive photoresist composition according to claim 1, characterized in that, The solvent comprises at least one of propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl acetate and ethyl lactate.

3. The positive photoresist composition according to claim 1, characterized in that, The positive photoresist composition comprises the following components by weight parts: Phenolic resin 10 - 60 parts, crosslinking agent 2 - 20 parts, acidic catalyst 0.2 - 5 parts, anionic initiator 0.2 - 5 parts and solvent 10 - 100 parts.

4. The positive photoresist composition according to claim 1, characterized in that, The positive photoresist composition comprises the following components by weight parts: Phenolic resin 50 parts, benzoguanamine 5 parts, ethanesulfonic acid 0.5 part, acetophenone O-benzoyl oxime 4 parts and propylene glycol monomethyl ether acetate 100 parts.

5. A method for preparing a positive photoresist composition according to any one of claims 1 to 4, characterized in that, It comprises the following steps: The solvent dissolves each component to obtain the positive photoresist composition.

6. The method for preparing a positive photoresist composition according to claim 5, characterized in that, After dissolution, it further comprises a filtration step; The filtration comprises filtration using a filter membrane; The pore size of the filter membrane is 0.01 - 1 micron.

7. Application of the positive photoresist composition according to any one of claims 1 - 4 in integrated circuit manufacturing.

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