A negative photoresist composition and its uses

Abstract

This invention provides a negative photoresist composition and its uses, relating to the field of photolithography. The negative photoresist composition comprises a solute and a first solvent; wherein the solute comprises 70wt%-96wt% alkali-soluble resin, 1wt%-30wt% photoacid-generating agent, 1wt%-20wt% crosslinking agent, 0.1wt%-15wt% acid quencher, 0.01wt%-3wt% surfactant, and 0.1wt%-0.2wt% special additives; the special additives are organic amine compounds; the mass of the first solvent is 1-15 times the mass of the alkali-soluble resin. This invention, by using specific types of organic amine compounds as special additives, can improve defects such as bottom corners and standing waves in photoresists.

Description

Technical Field

[0001] This invention belongs to the field of photolithography technology, specifically relating to a negative photoresist composition and its uses. Background Technology

[0002] Photoresist, also known as photoresist, is a thin-film etching material whose solubility changes upon exposure to ultraviolet light, electron beams, ion beams, X-rays, or other forms of radiation. It is used as an anti-corrosion coating material in the photolithography process. When processing semiconductor materials, using appropriate and selective photoresists can create the desired image on the surface. Photoresists are classified into two main categories based on the image they form: positive and negative. In the photoresist process, after exposure and development, the exposed areas are retained, while the unexposed areas are dissolved; this type of coating material is called negative photoresist.

[0003] With the development of miniaturized and high-performance devices, more intricate patterns are required. Therefore, photolithography, which uses photoresist, is often used for fine processing. In other words, in the manufacturing process of LEDs and semiconductor devices, photoresist is needed as a mask for pattern transfer.

[0004] During the research process of photoresist, technicians conducted further research on crosslinking agents: Chinese invention CN115947648A discloses a crosslinking agent and its preparation method, as well as a photoresist. The photoresist comprises a solute and a first solvent: the solute comprises 70wt%-95wt% alkali-soluble resin, 1wt%-30wt% photoacid-generating agent, 0.1wt%-15wt% acid quencher, and 5wt%-20wt% crosslinking agent; the mass of the first solvent is 1-10 times the mass of the alkali-soluble resin. The structural formula of the crosslinking agent is:

[0005]

[0006] Among them, R1, R2, R3, R4, and R5 are each independently selected from H, OH, or R 12 -OR 13 R7, R8, and R9 are each independently selected from H and C. 1-6 Saturated or unsaturated alkyl groups, C 1-6 Saturated or unsaturated cycloalkyl groups -OR 15 ,or The R 10 R 12 Each is independently selected from C 1-5 Alkyl; the R 11 R 13 R 14 R 15Each is independently selected from C 1-20 Alkyl; the R 16 R 17 R 18 R 19 and R 20 Each is independently selected from H, OH, or R 12 -OR 13 The crosslinking agent of this invention can be added to photoresist, making the crosslinking reaction of the photoresist matrix resin more uniform, reducing or avoiding morphological defects caused by excessively large local molecular weight, and resulting in more vertical edges of the pattern lines and larger windows.

[0007] Chinese invention patent CN113087843A discloses a polymer and a photoresist composition comprising the same. The photoresist composition includes a polymer, an alkali-soluble resin, a photosensitizer, a sensitivity modifier, a crosslinking agent, a solvent, and additives. The crosslinking agent is selected from amino-based, epoxy-based, ether-based, or urea-based crosslinking agents. The polymer is obtained by copolymerization of four monomers containing phenolic hydroxyl groups, imide groups, carboxyl groups, and hydroxyalkyl groups. This invention uses a specific polymer to prepare a photoresist that can improve the heat resistance of the photoresist while ensuring good developability.

[0008] However, photoresists are generally designed for specific exposure wavelengths. G-line 436nm, I-line 365nm, KrF 248nm, and ArF 193nm are currently the mainstream exposure light source wavelengths. During exposure, the light intensity distribution in the photoresist film exhibits a vertical gradient, resulting in uneven photon concentration and consequently uneven chemical reactions. This means that the cross-linking reaction between the resin and cross-linking agent varies at different locations within the pattern, making the produced pattern highly susceptible to defects. Traditional photoresists are prone to residual film. While adjusting the acid value can improve alkali solubility, excessively high acid values ​​lead to rapid development and low film retention. Insufficient heat resistance of the photoresist can cause pattern deformation during baking, resulting in right angles or inverted circles, affecting subsequent etching processes. Summary of the Invention

[0009] This invention addresses the problems existing in the prior art by providing a negative photoresist composition and its application, which can improve the topographic defects of the obtained pattern, such as bottom corners and standing waves.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] First, the present invention provides a negative photoresist composition, the raw material components of which include: a solute and a first solvent;

[0012] The solute comprises: 70wt%-96wt% alkali-soluble resin, 1wt%-30wt% photoacid-generating agent, 1wt%-20wt% crosslinking agent, 0.1wt%-15wt% acid quencher, 0.01wt%-3wt% surfactant and 0.1wt%-0.2wt% special additives;

[0013] The special additive is an organic amine compound;

[0014] The mass of the first solvent is 1-15 times the mass of the alkali-soluble resin.

[0015] Preferably, the mass fraction of the special additive in the solute is 0.11wt%-0.2wt%.

[0016] More preferably, the mass fraction of the special additive in the solute is 0.12wt%-0.2wt%.

[0017] More preferably, the mass fraction of the special additive in the solute is 0.14wt%-0.2wt%.

[0018] More preferably, the mass fraction of the special additive in the solute is 0.14wt%-0.17wt%.

[0019] In this invention, the mass fraction of the special additive in the solute can be any value within a range, including endpoints and intermediate values, for example: 0.1wt%-0.2wt%, 0.11wt%-0.2wt%, 0.12wt%-0.2wt%, 0.14wt%-0.2wt%, 0.14-0.17wt%, 0.1wt%-0.15wt%, 0.15wt%-0.2wt%, 0.12wt%, 0.13wt%, 0.14wt%, 0.15wt%, 0.16wt%, 0.17wt%, 0.18wt%, 0.19wt%, and 0.20wt%.

[0020] Preferably, the structural formula of the organic amine compound is:

[0021]

[0022] In the formula, R1, R2, R3, R4, R5, and R6 are each independently selected from C. 1-6 Saturated or unsaturated alkyl groups, C 1-6 Saturated or unsaturated cycloalkyl groups, -R7-OH;

[0023] R7 is selected from C. 1-6 Saturated or unsaturated alkyl groups, C 1-6 Saturated or unsaturated cycloalkyl groups.

[0024] More preferably, R1, R2, R3, R4, R5, and R6 are each independently selected from C. 1-4 Saturated or unsaturated alkyl groups, C 1-4 Saturated or unsaturated cycloalkyl groups.

[0025] More preferably, R1, R2, R3, R4, R5, and R6 are each independently selected from C. 1-2 Saturated or unsaturated alkyl groups, C 1-2 Saturated or unsaturated cycloalkyl groups.

[0026] More preferably, the organic amine compound is selected from... At least one of them.

[0027] Preferably, the alkali-soluble resin is selected from at least one of poly(p-hydroxystyrene) resin, polystyrene resin, poly(p-hydroxystyrene-styrene) resin, and linear phenolic resin.

[0028] Preferably, the photoacid-producing agent is selected from at least one of iodonium salts, thiodonium salts, and heterocyclic acid-producing agents.

[0029] Preferably, the crosslinking agent is an etherified polyphenyl crosslinking agent.

[0030] More preferably, the crosslinking agent is a 1,3,4,6-tetra(methoxymethyl)glycourea crosslinking agent.

[0031] Preferably, the acid quencher is an alkaline organic compound.

[0032] More preferably, the acid quencher is a tertiary ammonium compound and / or a quaternary ammonium compound.

[0033] More preferably, the acid quencher is selected from at least one of trioctylamine, tributylamine, trimethoxyethoxymethoxyethylamine, tetramethylammonium hydroxide, and triethanolamine.

[0034] Preferably, the surfactant is BYK307.

[0035] Preferably, the mass of the first solvent is 3-10 times the mass of the alkali-soluble resin.

[0036] More preferably, the mass of the first solvent is 5.3-7.9 times the mass of the alkali-soluble resin.

[0037] More preferably, the mass of the first solvent is 6.4-6.6 times the mass of the alkali-soluble resin.

[0038] Preferably, the first solvent is selected from at least one of 1,2-propanediol methyl ether acetate, ethyl lactate, and ethyl acetate.

[0039] Preferably, the solute in the negative photoresist composition includes: 80wt%-90wt% alkali-soluble resin, 3wt%-8wt% photoacid generator, 2wt%-8wt% crosslinking agent, 0.2wt%-1wt% acid quencher, 0.02wt%-1wt% surfactant, and 0.12wt%-0.2wt% special additives.

[0040] More preferably, the solute in the negative photoresist composition includes: 80wt%-90wt% alkali-soluble resin, 3wt%-8wt% photoacid generator, 2wt%-8wt% crosslinking agent, 0.2wt%-1wt% acid quencher, 0.02wt%-1wt% surfactant, and 0.14wt%-0.2wt% special additives.

[0041] More preferably, the solute in the negative photoresist composition includes: 86wt%-88wt% alkali-soluble resin, 5.5wt%-6wt% photoacid generator, 5.5wt%-6wt% crosslinking agent, 0.4wt%-0.5wt% acid quencher, 0.08wt%-0.1wt% surfactant, and 0.14wt%-0.2wt% special additives.

[0042] More preferably, the solute in the negative photoresist composition comprises: 87.78 wt% alkali-soluble resin, 5.97 wt% photoacid-generating agent, 5.58 wt% crosslinking agent, 0.44 wt% acid quencher, 0.085 wt% surfactant, and 0.14 wt%-0.17 wt% special additives.

[0043] In this invention, the special additive can decompose into ammonia compounds upon heating, thus mitigating the generation of H+ due to exposure to photoacid-producing agents. + Defects such as bottom corners and standing waves caused by excessively rapid migration.

[0044] Then, the present invention provides a method for preparing the above-mentioned negative photoresist composition, comprising the steps of: mixing and dissolving the raw material components in the negative photoresist composition, filtering, and obtaining the negative photoresist composition.

[0045] Preferably, the filtration is performed using a 0.1-0.24 μm polytetrafluoroethylene microporous filter membrane.

[0046] Finally, the present invention provides the application of the above-described negative photoresist composition in the preparation of photoresists without bridging and bottom corner defects.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The negative photoresist composition of the present invention improves defects such as bottom corners and standing waves of photoresist by using specific types of organic amine compounds as special additives. The negative photoresist of the present invention exhibits fewer or no morphological defects during use, and the edges of the pattern lines are more vertical. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the pattern formed after developing the negative photoresist in Example 1.

[0050] Figure 2 This is a schematic diagram of the pattern formed after developing the negative photoresist in Example 2.

[0051] Figure 3 This is a schematic diagram of the pattern formed after developing the negative photoresist in Example 3.

[0052] Figure 4 This is a schematic diagram of the pattern formed after developing the negative photoresist in Example 4.

[0053] Figure 5 This is a schematic diagram of the pattern formed after developing the negative photoresist in Example 5.

[0054] Figure 6 This is a schematic diagram of the pattern formed after developing the negative photoresist in Example 6.

[0055] Figure 7 This is a schematic diagram of a defective pattern formed after developing the negative photoresist of Comparative Example 1.

[0056] Figure 8 This is a schematic diagram of a defective pattern formed after developing the negative photoresist in Comparative Example 2.

[0057] Figure 9 This is a schematic diagram of a defective pattern formed after developing the negative photoresist in Comparative Example 3.

[0058] Figure 10 This is a schematic diagram of a defective pattern formed after developing the negative photoresist in Comparative Example 4.

[0059] Figure 11 This is a schematic diagram of a defective pattern formed after developing the negative photoresist of Comparative Example 5.

[0060] Figure 12 This is a schematic diagram of a defective pattern formed after developing the negative photoresist of Comparative Example 6. Detailed Implementation

[0061] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes should also fall within the scope of protection claimed by the present invention.

[0062] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0063] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present invention are obtained through conventional commercial means.

[0064] In the following examples, the poly(p-hydroxystyrene)-styrene resin was purchased from Maruzen Chemical Co., Ltd., Japan; the trifluoromethanesulfonate iodonium salt, 1,3,4,6-tetra(methoxymethyl)glycourea, BYK307, 1,2-propanediol methyl ether acetate, and tetraazatricyclodecane were all purchased from Aladdin Biochemical Technology Co., Ltd. The different manufacturers of these components did not significantly affect the efficacy.

[0065] Example 1

[0066] A negative photoresist composition, comprising: 11.68g poly(p-hydroxystyrene)-styrene resin, 0.795g trifluoromethanesulfonate iodonium salt, 0.742g 1,3,4,6-tetra(methoxymethyl)glycourea crosslinking agent, 0.0584g trioctylamine, 0.0113g surfactant BYK307 and 0.02g organic amine compound; and 75.42g 1,2-propanediol methyl ether acetate.

[0067] Before mixing, trioctylamine was prepared into a 1 wt% solution using the first solvent; the surfactant was prepared into a 1 wt% solution using the first solvent.

[0068] After mixing the above substances, stir them thoroughly to ensure complete dissolution, and then filter them through a 0.1μm polytetrafluoroethylene microporous membrane to obtain negative photoresist.

[0069] In this embodiment, the organic amine compound used is tetraazatricyclodecane (CAS: 100-97-0);

[0070]

[0071] Example 2

[0072] Unlike Example 1, the organic amine compound is: tetraazatricycloundecane (CAS: 125251-91-4);

[0073]

[0074] Everything else is the same as in Example 1.

[0075] Example 3

[0076] Unlike Example 1, the organic amine compound is tetraazatricyclododecane (CAS: 51-46-7);

[0077]

[0078] Everything else is the same as in Example 1.

[0079] Example 4

[0080] Unlike Example 1, the organic amine compound is 2-methyl-tetraazatricyclodecane (CAS: 66591-66-0);

[0081]

[0082] Everything else is the same as in Example 1.

[0083] Example 5

[0084] The difference from Example 1 is that the amount of organic amine compound used is different, with 0.018 g added. Everything else is the same as in Example 1.

[0085] Example 6

[0086] The difference from Example 1 is that the amount of organic amine compound used is different, with 0.022 g added. Everything else is the same as in Example 1.

[0087] Comparative Example 1

[0088] Unlike Example 1, no organic amine compounds were used in the raw material components. Specifically:

[0089] A negative photoresist composition, comprising: 11.68g poly(p-hydroxystyrene)-styrene resin, 0.795g trifluoromethanesulfonate iodonium salt, 0.742g 1,3,4,6-tetra(methoxymethyl)glycourea crosslinking agent, 0.0584g trioctylamine, 0.0113g surfactant BYK307 and 0.02g organic amine compound; and 75.42g 1,2-propanediol methyl ether acetate.

[0090] Before mixing, trioctylamine was prepared into a 1 wt% solution using the first solvent; the surfactant was prepared into a 1 wt% solution using the first solvent.

[0091] After mixing the above substances, stir them thoroughly to ensure complete dissolution, and then filter them through a 0.1μm polytetrafluoroethylene microporous membrane to obtain negative photoresist.

[0092] Comparative Example 2

[0093] The difference from Example 1 is that the organic amine compound was replaced with p-toluidine. Everything else is the same as in Example 1.

[0094] Comparative Example 3

[0095] The difference from Example 1 is that the organic amine compound was replaced with triethanolamine. Everything else is the same as in Example 1.

[0096] Comparative Example 4

[0097] The difference from Example 1 is that the crosslinking agent was replaced with hexamethoxymethyl melamine. Everything else is the same as in Example 1.

[0098] Comparative Example 5

[0099] The difference from Example 1 is that the amount of organic amine compound used is different, with 0.01 g added. Everything else is the same as in Example 1.

[0100] Comparative Example 6

[0101] The difference from Example 1 is that the amount of organic amine compound used is different, with 0.03 g added. Everything else is the same as in Example 1.

[0102] Figures 1-6 These are schematic diagrams of the patterns formed after developing the negative photoresist in Examples 1-6.

[0103] Figures 7-12 These are schematic diagrams of defective patterns formed after developing negative photoresist, specifically Comparative Examples 1 to 6.

[0104] Experiment 1

[0105] The negative photoresist compositions of each embodiment and comparative example were spin-coated onto an 8-inch single-crystal silicon wafer. After coating, the substrate coated with the negative photoresist composition was pre-baked at 110°C for 60s using a hot plate. The rotation speed was adjusted to make the film thickness 0.55μm after drying. The substrate was then exposed using a DUV exposure machine. After exposure, the substrate was post-baked at 115°C for 60s using a hot plate. Finally, the substrate was spray-developed with 2.38wt% tetramethylammonium hydroxide for 50s.

[0106] After the operation, the exposure energy latitude and depth of focus were measured using a CD-SEM (Hitachi S9220), and the undercut and standing wave characteristics of the image at the optimal energy were observed using an X-SEM (S4800). The undercut, standing wave characteristics, exposure energy latitude, and depth of focus effects are shown in Table 1.

[0107] Table 1

[0108] Bottom corner case Standing wave situation Exposure energy tolerance (%) Depth of focus (μm) Example 1 No bottom corner No standing wave 22.3％ 0.50 Example 2 No bottom corner No standing wave 22.1％ 0.50 Example 3 No bottom corner No standing wave 22.1％ 0.50 Example 4 No bottom corner No standing wave 22.8％ 0.50 Example 5 No bottom corner No standing wave 21.9％ 0.50 Example 6 No bottom corner No standing wave 21.8％ 0.50 Comparative Example 1 With bottom corner Standing waves 19.7％ 0.40 Comparative Example 2 With bottom corner Standing waves 19.2％ 0.35 Comparative Example 3 With bottom corner Standing waves 19.6％ 0.40 Comparative Example 4 With bottom corner Standing waves 17.3％ 0.35 Comparative Example 5 With bottom corner Standing waves 21.5％ 0.45 Comparative Example 6 With bottom corner Standing waves 19.8％ 0.40

[0109] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A negative photoresist composition, characterized in that, The raw material components include: solute and first solvent; The solute is composed of the following components in parts by weight: 70wt%-96wt% alkali-soluble resin, 1wt%-30wt% photoacid-generating agent, 1wt%-20wt% crosslinking agent, 0.1wt%-15wt% acid quencher, 0.01wt%-3wt% surfactant and 0.14wt%-0.17wt% special additives; The mass of the first solvent is 1-15 times the mass of the alkali-soluble resin; The special additive is selected from , , , At least one of them; The crosslinking agent is 1, 3, 4, or 6. Tetra(methoxymethyl)glycourea crosslinking agent.

2. The negative photoresist composition according to claim 1, characterized in that, The alkali-soluble resin is selected from at least one of poly(p-hydroxystyrene) resin, polystyrene resin, poly(p-hydroxystyrene-styrene) resin, and linear phenolic resin; The photo-induced acid-producing agent is selected from at least one of iodonium salts, thiodonium salts, and heterocyclic acid-producing agents; The acid quencher is an alkaline organic compound; The surfactant is BYK307; The mass of the first solvent is 3-10 times the mass of the alkali-soluble resin; The first solvent is selected from at least one of 1,2-propanediol methyl ether acetate, ethyl lactate, and ethyl acetate.

3. The negative photoresist composition according to claim 1, characterized in that, The solute is made from the following components in parts by weight: 80wt%-90wt% alkali-soluble resin, 3wt%-8wt% photoacid generator, 2wt%-8wt% crosslinking agent, 0.2wt%-1wt% acid quencher, 0.02wt%-1wt% surfactant and 0.14wt%-0.17wt% special additives.

4. A method for preparing the negative photoresist composition according to any one of claims 1-3, characterized in that, The process includes the following steps: mixing and dissolving the raw material components in the negative photoresist composition, filtering, and obtaining the negative photoresist composition.

5. The use of the negative photoresist composition according to any one of claims 1-3 in the preparation of photoresists without bridging and bottom corner defects.

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