Anti-reflection coating composition as well as application and coating structure thereof

Abstract

The invention discloses an anti-reflection coating composition as well as application and a coating structure thereof, and belongs to the technical field of photoetching. The anti-reflection coating composition is prepared from the following components in percentage by mass: 1 to 30 weight percent of extinction resin system, 0.1 to 1.5 weight percent of catalyst, 0.2 to 1.5 weight percent of cross-linking agent and 67 to 98.7 weight percent of solvent, the extinction resin system comprises first extinction resin and second extinction resin, and the extinction coefficient k value of the first extinction resin is greater than the extinction coefficient k value of the second extinction resin; the first matting resin and the second matting resin are compounded, so that the matting coefficient k value of the matting resin system is 0.4-0.7. Therefore, the prepared anti-reflection layer can realize a relatively strong anti-reflection effect under the condition of relatively low thickness.

Description

Technical Field

[0001] The present invention relates to the field of lithography technology, and particularly relates to an anti-reflection coating composition, its application, and a coating structure. Background Art

[0002] In order to improve the clarity and resolution of lithography patterns, a photoresist layer and an anti-reflection layer are usually used in combination. If the photoresist layer is coated on top of the anti-reflection layer, the anti-reflection layer is called a Bottom Anti-Reflection Coating (BARC). If the anti-reflection layer is coated on top of the photoresist, the anti-reflection layer is called a Top Anti-Reflection Coating (TARC). Compared with the top anti-reflection layer, the bottom anti-reflection layer has a more obvious effect in reducing the swing effect and the notch effect, and is currently a widely used solution for eliminating reflectivity.

[0003] The composition of the bottom anti-reflection layer BARC can generally be divided into two systems: inorganic and organic. Among them, the organic BARC is prepared by a spin coating process using a polymer material. However, the current bottom anti-reflection layer BARC based on the organic system has at least the following technical problems:

[0004] The thickness of the bottom anti-reflection layer BARC is usually designed to be relatively thick to achieve a strong anti-reflection effect. Summary of the Invention

[0005] In view of this, the present invention provides an anti-reflection coating composition, its application, and a coating structure, which can solve the technical problems existing in the related art.

[0006] Specifically, the following technical solutions are included:

[0007] On the one hand, an anti-reflection coating composition is provided, and the anti-reflection coating composition includes the following components in mass percentages:

[0008] 1 wt% - 30 wt% of a matting resin system, 0.1 wt% - 1.5 wt% of a catalyst, 0.2 wt% - 1.5 wt% of a crosslinking agent, 67 wt% - 98.7 wt% of a solvent;

[0009] The matting resin system includes a first matting resin and a second matting resin, and the extinction coefficient k value of the first matting resin is greater than the extinction coefficient k value of the second matting resin;

[0010] The compounding of the first matting resin and the second matting resin makes the extinction coefficient k value of the matting resin system be 0.4 - 0.7.

[0011] In some possible implementation manners, the extinction coefficient k value of the first extinction resin ranges from 0.7 to 0.9;

[0012] The extinction coefficient k value of the second extinction resin ranges from 0.05 to 0.2.

[0013] In some possible implementation manners, the first extinction resin is prepared by a chemical grafting reaction of a first matrix resin and a first dyeing compound, wherein the molar percentage of the first dyeing compound in the reaction system is 20%-40%.

[0014] In some possible implementation manners, the first matrix resin is selected from at least one of acrylic resin, phenolic resin, epoxy resin, polyimide resin, and olefin resin;

[0015] The first dyeing compound is selected from at least one of anthracene and its derivatives, coumarin and its derivatives, fluorescein and its derivatives, rhodamine, eosin, perylene and its derivatives, fluorene and its derivatives, and stilbene and its derivatives.

[0016] In some possible implementation manners, the second extinction resin is prepared by a chemical grafting reaction of a second matrix resin and a second dyeing compound, wherein the molar percentage of the second dyeing compound in the reaction system is 5%-20%.

[0017] In some possible implementation manners, the second matrix resin is selected from at least one of acrylic resin, phenolic resin, epoxy resin, polyimide resin, and olefin resin;

[0018] The second dyeing compound is selected from at least one of anthracene and its derivatives, coumarin and its derivatives, fluorescein and its derivatives, rhodamine, eosin, perylene and its derivatives, fluorene and its derivatives, and stilbene and its derivatives.

[0019] In some possible implementation manners, the catalyst is an organic acid salt catalyst;

[0020] The organic acid salt catalysts include at least one of p-toluenesulfonate, phenol sulfonate, dodecyl sulfonate, trifluoromethanesulfonic acid, naphthalene sulfonate, naphthalene disulfonate, quinoline-8-sulfonate, methanesulfonate, ethanesulfonate, butanesulfonate, oxalate, and camphorsulfonate.

[0021] In some possible implementation manners, the crosslinking agent includes at least one of melamine-formaldehyde resin, glycoluril-formaldehyde resin, urea-formaldehyde resin, melamine resin, isocyanate, and glycoluril compound.

[0022] On the other hand, provided is the application of any one of the above antireflection coating compositions in a lithography process.

[0023] In another aspect, a coating structure is provided, which includes: a substrate, a bottom antireflection layer, and a photoresist layer;

[0024] The bottom antireflection layer is formed on the substrate by any one of the above antireflection coating compositions;

[0025] The photoresist layer is formed on the bottom antireflection layer.

[0026] In some possible implementation manners, the bottom antireflection layer can absorb radiation with a wavelength of 100 nm - 400 nm.

[0027] The beneficial effects of the technical solution provided by the embodiments of the present invention at least include:

[0028] The antireflection coating composition provided by the present invention improves its extinction resin system, making it include a first extinction resin with a high k value and a second extinction resin with a low k value. The compounding effect of the two resins with different k values can adjust the k value of the extinction coefficient of the extinction resin system within the range of 0.4 - 0.7 by adjusting the ratio between the two. This is beneficial to achieving a strong antireflection effect with a relatively low thickness of the prepared antireflection layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0030] Figure 1 It is the UV test curve of the PM eluent corresponding to Example 1;

[0031] Figure 2 It is the scanning electron microscope image of the test sample shown in Example 1;

[0032] Figure 3 It is the scanning electron microscope image of the test sample shown in Comparative Example 4. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] To make the technical solutions and advantages of the present invention clearer, the following will further describe the embodiments of the present invention in detail with reference to the drawings.

[0034] In the lithography process, the line width uniformity within a block directly affects the critical dimension (CD) and resolution of the pattern. The influencing factors for the line width uniformity within a block include uneven substrate reflectivity, different photoresist film thicknesses above and below steps, etc. As the feature size decreases, the line width non-uniformity and photoresist pits caused by the high-reflection layer, as well as the lateral photoreaction due to scattering of solid particles in the photoresist film during lithography, deteriorate the topography.

[0035] To improve the clarity and resolution of the lithography pattern, the photoresist layer is usually used in combination with an anti-reflection layer. For example, if the photoresist layer is coated on top of the anti-reflection layer, the anti-reflection layer is called the bottom anti-reflection coating (BARC). If the anti-reflection layer is coated on top of the photoresist, the anti-reflection layer is called the top anti-reflection coating (TARC). Compared with the top anti-reflection layer, the bottom anti-reflection layer has a more obvious effect in reducing the swing effect and notch effect, and is currently a widely used solution for eliminating reflectivity.

[0036] The composition of the bottom anti-reflection layer BARC can generally be divided into two systems: inorganic and organic. The organic BARC is prepared by a spin-coating process using polymer materials. The principle is that the dyeing groups in the polymer absorb ultraviolet light to reduce the matrix reflectivity.

[0037] However, currently, the bottom anti-reflection layer BARC based on the organic system has at least the following technical problems: The thickness of the bottom anti-reflection layer BARC is usually designed to be relatively thick to achieve a strong anti-reflection effect. However, this makes its removal difficult and increases the process cost.

[0038] In view of the technical problems existing in the related art, an embodiment of the present invention provides an anti-reflection coating composition, which includes the following components in mass percentages:

[0039] 1 wt% - 30 wt% of a matting resin system, 0.1 wt% - 1.5 wt% of a catalyst, 0.2 wt% - 1.5 wt% of a cross-linking agent, and 67 wt% - 98.7 wt% of a solvent.

[0040] For example, the anti-reflection coating composition provided by the embodiment of the present invention may further include the following components in mass percentages:

[0041] 5 wt% - 25 wt% of a matting resin system, 0.5 wt% - 1.2 wt% of a catalyst, 0.5 wt% - 1.2 wt% of a cross-linking agent, and 82 wt% - 95 wt% of a solvent.

[0042] Regarding the mass percentages of the components in the anti-reflection coating composition, some specific examples include but are not limited to the following:

[0043] The mass percentage of the matting resin system includes but is not limited to: 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt%, 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, 30wt%, etc.

[0044] The mass percentage of the catalyst includes but is not limited to: 0.1wt%, 0.2wt%, 0.25wt%, 0.3wt%, 0.35wt%, 0.4wt%, 0.45wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, etc.

[0045] The mass percentage of the crosslinking agent includes but is not limited to: 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.55wt%, 0.6wt%, 0.65wt%, 0.7wt%, 0.75wt%, 0.8wt%, 0.85wt%, 0.9wt%, 0.95wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, etc.

[0046] The mass percentage of the solvent includes but is not limited to: 70wt%, 75wt%, 80wt%, 85wt%, 90wt%, 95wt%, etc. In some examples, the amount of the solvent can be the balance to satisfy that the sum of the mass percentages of the matting resin system, the catalyst, the crosslinking agent, and the solvent reaches 100%.

[0047] In particular, the matting resin system includes a first matting resin and a second matting resin, and the extinction coefficient k value of the first matting resin is greater than the extinction coefficient k value of the second matting resin. The first matting resin and the second matting resin are compounded so that the extinction coefficient k value of the matting resin system is 0.4 - 0.7. For example, the value range of the extinction coefficient k value of the matting resin system includes but is not limited to: 0.4 - 0.5, 0.4 - 0.6, 0.4 - 0.65, 0.45 - 0.5, 0.45 - 0.6, 0.45 - 0.65, 0.45 - 0.7, 0.5 - 0.6, 0.5 - 0.65, 0.5 - 0.7, 0.6 - 0.65, 0.6 - 0.7, etc.

[0048] For further illustration, some values of the extinction coefficient k of the extinction resin system can be as follows: 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.7, etc.

[0049] It should be noted that the "extinction coefficient k value" involved in the embodiments of the present invention refers to the degree to which light is absorbed or scattered after passing through the current material. Its value is the ratio of the natural logarithm of the light intensity to the thickness within a unit thickness, that is, k = ln(IO / I) / d, where IO is the incident light intensity, I is the transmitted light intensity, and d is the material thickness. The larger the extinction coefficient k value, the stronger the absorption or scattering of the material to light, and the lower the transparency of the material.

[0050] The antireflection coating composition provided by the present invention improves the extinction resin system so that it includes a first extinction resin with a high k value and a second extinction resin with a low k value. The combined action of the two resins with different k values can adjust the extinction coefficient k value of the extinction resin system within the range of 0.4 - 0.7 by adjusting the ratio of the two, which is beneficial to achieving a strong antireflection effect with a relatively low thickness of the prepared antireflection layer.

[0051] In some examples, the value range of the extinction coefficient k of the first extinction resin is 0.7 - 0.9, which includes but is not limited to 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, etc.

[0052] The value range of the extinction coefficient k of the second extinction resin is 0.05 - 0.2, which includes but is not limited to 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, etc.

[0053] By compounding the first extinction resin and the second extinction resin with k values within the above ranges, the extinction coefficient k value of the extinction resin system can be adjusted within the range of 0.4 - 0.7.

[0054] As described above, the total mass percentage of the first matting resin and the second matting resin in the antireflection coating composition is 1 wt% - 30 wt%, and further can be 1% - 20%.

[0055] In the embodiments of the present invention, the mass ratio of the first matting resin to the second matting resin can be 1:10 - 10:1, which includes but is not limited to: 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, etc. It is only necessary to adjust the mass ratio of the first matting resin and the second matting resin according to the magnitude of the extinction coefficient k value of the matting resin system.

[0056] The larger the amount of the first matting resin, the larger the extinction coefficient k value of the matting resin system. On the contrary, the smaller the amount of the first matting resin, the smaller the extinction coefficient k value of the matting resin system.

[0057] Furthermore, the refractive index n value of the first matting resin is 1.45 - 1.55, which includes but is not limited to 1.45, 1.46, 1.47, 1.48, 1.49, 1.5, 1.51, 1.52, 1.53, 1.54, 1.55, etc. The refractive index n value of the second matting resin is 1.45 - 1.55, which includes but is not limited to 1.45, 1.46, 1.47, 1.48, 1.49, 1.5, 1.51, 1.52, 1.53, 1.54, 1.55, etc.

[0058] During application, the refractive index n value of the first matting resin can be equal to the refractive index n value of the second matting resin, or can be different from the refractive index n value of the second matting resin.

[0059] The refractive index n value of the resin generally depends on the resin type. When the first matting resin and the second matting resin select the same type of matrix resin, for example, both use acrylic resin as the matrix resin, the difference in the n values of the first matting resin and the second matting resin is small, and the influence of the dyeing compound on the n value is also small. In this way, when the first matting resin and the second matting resin are compounded in different proportions, although the k value of the matting resin system can be adjusted within the range of 0.4 - 0.7, however, the change range of the n value of the matting resin system is relatively low, and even the n value can remain unchanged.

[0060] In some examples, the weight-average molecular weight Mw of the first matting resin is 8,000 - 40,000, further 10,000 - 40,000, 10,000 - 30,000, or 15,000 - 25,000. The weight-average molecular weight Mw of the second matting resin is 8,000 - 40,000, further 10,000 - 40,000, 10,000 - 30,000, or 15,000 - 25,000.

[0061] The proportion of the matting resin can be adjusted according to its weight-average molecular weight and viscosity so that the viscosity of the antireflection coating composition is within the desired range.

[0062] In the embodiments of the present invention, the first matting resin is prepared by a chemical grafting reaction of a first matrix resin and a first dyeing compound. The molar percentage of the first dyeing compound in the reaction system is 20% - 40%. The reaction system involved here refers to the reaction system composed of the first matrix resin and the first dyeing compound. By grafting the first dyeing compound onto the first matrix resin to form the first matting resin, the molar ratio of the first dyeing compound is controlled to be 20% - 40%, so that the extinction coefficient k value of the first matting resin ranges from 0.7 to 0.9.

[0063] In the embodiments of the present invention, the first matrix resin is selected from at least one of acrylic resin, phenolic resin, epoxy resin, polyimide resin, and olefin resin. The first dyeing compound is selected from at least one of anthracene and its derivatives, coumarin and its derivatives, fluorescein and its derivatives, rhodamine, eosin, perylene and its derivatives, fluorene and its derivatives, stilbene and its derivatives.

[0064] Exemplarily, the derivatives of anthracene involved in the first dyeing compound include but are not limited to: 2-anthracene carboxylic acid, 9-anthracene carboxylic acid, 2-vinyl anthracene, 9-vinyl anthracene, 9-hydroxymethyl anthracene, etc. The derivatives of coumarin include but are not limited to: 4-hydroxycoumarin, 7-hydroxycoumarin, etc. The derivatives of fluorescein include but are not limited to: fluorescein isothiocyanate, etc. Rhodamine can be rhodamine B, rhodamine 6G, etc. Eosin can be eosin-Y, eosin-B, etc. The derivatives of perylene can be 3,4,9,10-perylene tetracarboxylic dianhydride, etc. The derivatives of fluorene can be 9-fluorenol, 1-fluorene carboxylic acid, 9-fluorene carboxylic acid, 9,9-bis(4-hydroxyphenyl)fluorene, etc. The derivatives of stilbene can be 4,4'-stilbene dicarboxylic acid, etc.

[0065] In the embodiments of the present invention, the second matting resin is prepared by a chemical grafting reaction of a second matrix resin and a second dyeing compound, wherein the molar percentage of the second dyeing compound in the reaction system is 5% - 20%. The reaction system involved here refers to the reaction system composed of the second matrix resin and the second dyeing compound.

[0066] The second matting resin is formed by grafting a second dyeing compound onto a second matrix resin. The molar ratio of the second dyeing compound is controlled to be 5%-20%, so that the extinction coefficient k value of the second matting resin ranges from 0.05 to 0.2.

[0067] In the embodiments of the present invention, the second matrix resin is selected from at least one of acrylic resin, phenolic resin, epoxy resin, polyimide resin, and olefin resin, and the second dyeing compound is selected from at least one of anthracene and its derivatives, coumarin and its derivatives, fluorescein and its derivatives, rhodamine, eosin, perylene and its derivatives, fluorene and its derivatives, stilbene and its derivatives.

[0068] Exemplarily, the derivatives of anthracene involved in the second dyeing compound include but are not limited to: 2-anthracene carboxylic acid, 9-anthracene carboxylic acid, 2-vinyl anthracene, 9-vinyl anthracene, 9-hydroxymethyl anthracene, etc. The derivatives of coumarin include but are not limited to: 4-hydroxycoumarin, 7-hydroxycoumarin, etc. The derivatives of fluorescein include but are not limited to: fluorescein isothiocyanate, etc. Rhodamine can be rhodamine B, rhodamine 6G, etc. Eosin can be eosin-Y, eosin-B, etc. The derivatives of perylene can be 3,4,9,10-perylene tetracarboxylic dianhydride, etc. The derivatives of fluorene can be 9-fluorenol, 1-fluorene carboxylic acid, 9-fluorene carboxylic acid, 9,9-bis(4-hydroxyphenyl)fluorene, etc. The derivatives of stilbene can be 4,4'-stilbene dicarboxylic acid, etc.

[0069] In the embodiments of the present invention, both the first matting resin and the second matting resin are used as film-forming resins, providing good film-forming properties and at the same time having high light absorption properties, absorbing light during the lithography process to avoid deformation of the lithography pattern caused by light reflection or diffraction.

[0070] In some examples, when preparing the first matting resin, under the action of an initiator, a first matrix resin and a first dyeing compound with a set molar ratio can react at a temperature of 110°C - 150°C for 8 hours - 24 hours, and after separation treatment, the first matting resin is prepared.

[0071] When preparing the second matting resin, under the action of an initiator, a second matrix resin and a second dyeing compound with a set molar ratio can react at a temperature of 110°C - 150°C for 8 hours - 24 hours, and after separation treatment, the second matting resin is prepared.

[0072] In the embodiments of the present invention, the catalyst may be an organic acid salt catalyst. Exemplarily, the organic acid salt catalyst includes at least one of p-toluenesulfonate, phenolsulfonate, dodecylsulfonate, trifluoromethanesulfonate, naphthalenesulfonate, naphthalenedisulfonate, quinoline-8-sulfonate, methanesulfonate, ethanesulfonate, butanesulfonate, oxalate, camphorsulfonate. Additionally, the salts involved above may be sodium salts, potassium salts or amine salts. For example, a catalyst may be triethylamine 1,5-naphthalenedisulfonate.

[0073] The organic acid salt catalyst can generate protonic acid under heating conditions to promote the curing reaction of the resin and the crosslinking agent. If the catalyst content is too high, it will cause the colloid to crosslink due to the acid generated during storage, resulting in poor storage stability. If the catalyst content is too low, the crosslinking reaction is incomplete, leading to the precipitation of excess solvent. Therefore, the content of the catalyst is 0.1 wt% - 1.5 wt%, and further can be 0.5 wt% - 1.2 wt%.

[0074] Using the above-mentioned organic acid salts as catalysts, because, additionally, the organic acid salt catalysts are stable at room temperature and do not initiate the crosslinking reaction of polymers in the system, improving the storage stability of the antireflection coating composition. When the antireflection coating composition is applied, the organic acid salt catalyst is decomposed into acid and base at high temperature after baking, and the acid therein can catalyze the crosslinking reaction. It can be seen that the embodiments of the present invention using organic acid salt catalysts can effectively improve the thermal stability of the antireflection coating composition.

[0075] The crosslinking agent plays a crosslinking role in the antireflection coating composition, crosslinking the resins into a network structure, so that it has good adhesion after film formation. In some examples, the crosslinking agent has functional groups capable of reacting with groups (such as hydroxyl groups, carboxyl groups, etc.) in the matting resin. For example, amino resin types, isocyanate types.

[0076] In some examples, some suitable crosslinking agents may be at least one of melamine-formaldehyde resin, glycoluril-formaldehyde resin, urea-formaldehyde resin, melamine resin, isocyanate, glycoluril compound. For example, the glycoluril compound includes tetramethoxymethyl glycoluril, and tetramethoxymethyl glycoluril can be used as the crosslinking agent.

[0077] The solvent plays a role in dispersing the resin, achieving the coating function and improving the uniformity. Exemplarily, the solvent includes but is not limited to: at least one of ethyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclopentanone, cyclohexanone, methyl ether. When two or more solvents are used, the solubility of the solid components can be enhanced.

[0078] For example, some examples are that the solvent is propylene glycol methyl ether and propylene glycol methyl ether acetate, and the mass ratio of the two is 5-10:2-5, which includes but is not limited to 5:2, 5:3, 5:4, 1:1, 3:1, 2:1, 3:2, 6:5, 7:2, 7:3, 7:4, 7:5, 4:1, 8:3, 8:5, 9:2, 9:4, 9:5, 5:1, 10:3, etc.

[0079] In summary, based on the above antireflection coating composition provided by the embodiments of the present invention, its extinction resin system containing a dual resin crosslinks and cures with a crosslinking agent under the action of a catalyst, and can form a uniform antireflection layer, strongly absorbing radiation in the range of 100nm - 400nm, which includes but is not limited to radiation of 100nm, 120nm, 140nm, 160nm, 180nnm, 200nm, 220m, 248nm, 260nm, 280nm, 300nm, 320nm, 340nm, 360nm, 380nm, 400nm, etc. Based on the antireflection coating of this antireflection coating composition, its extinction coefficient k value reaches above 0.4, the refractive index n value is 1.45 - 1.55, it has a high plasma etching rate, and can be paired with a relatively thin (0.2um - 2um) photoresist layer to open a window through etching, thereby processing the substrate.

[0080] In addition, the antireflection coating composition provided by the embodiments of the present invention and the antireflection layer prepared therefrom, based on its formulation composition, especially the use of organic acid salt catalysts, also have good storage stability and a wider storage temperature range. For example, they can be stably stored in the range of -15°C - 40°C, and moreover, the storage period is at least 12 months, and the storage period can reach six months at ultra-low temperature (-35°C).

[0081] According to the second aspect of the embodiments of the present invention, an application of any of the above antireflection coating compositions is also provided. For example, this application can be the application of the antireflection coating composition in a lithography process.

[0082] According to the third aspect of the embodiments of the present invention, a coating structure is also provided. This coating structure includes: a substrate, a bottom antireflection layer, and a photoresist layer; the bottom antireflection layer is formed on the substrate by any of the above antireflection coating compositions; the photoresist layer is formed on the bottom antireflection layer.

[0083] The coating structure provided by the embodiments of the invention has all the advantages of the above-mentioned antireflection coating composition.

[0084] The present invention will be further specifically described below through specific embodiments. It is necessary to point out here that the following embodiments are only used to further illustrate the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention still fall within the protection scope of the present invention.

[0085] An antireflection coating composition is provided through each of the following examples and each of the comparative examples, and the formulations of these antireflection coating compositions are shown in Tables 1 - 6 below.

[0086] The acrylic resin A involved in the following antireflection coating composition can be prepared through the following method:

[0087] A monomer mixture is composed of 15 parts by weight of methyl methacrylate, 5 parts by weight of phenyl methacrylate, 10 parts by weight of 2-hydroxyethyl acrylate, 68 parts by weight of glycidyl methacrylate, and 2 parts by weight of azobisisobutyronitrile (AIBN). The monomer mixture is uniformly mixed with 200 parts by weight of propylene glycol methyl ether and reacted at 80 °C for 7 h to prepare an acrylic resin. 106 parts by weight of 2-anthracene carboxylic acid is continuously added to the reaction system, and the temperature is raised to 120 °C and reacted for 12 h, then the reaction is stopped. The reaction system is subjected to treatments such as water washing and drying to prepare a dry acrylic resin A.

[0088] The acrylic resin B involved in the following antireflection coating composition can be prepared through the following method:

[0089] A monomer mixture is composed of 40 parts by weight of methyl methacrylate, 5 parts by weight of phenyl methacrylate, 33 parts by weight of 2-hydroxyethyl acrylate, 20 parts by weight of glycidyl methacrylate, and 2 parts by weight of azobisisobutyronitrile (AIBN). The monomer mixture is uniformly mixed with 200 parts by weight of propylene glycol methyl ether and reacted at 80 °C for 7 h to prepare an acrylic resin. 31 parts by weight of 2-anthracene carboxylic acid is continuously added to the reaction system, and the temperature is raised to 120 °C and reacted for 12 h, then the reaction is stopped. The reaction system is subjected to treatments such as water washing and drying to prepare a dry acrylic resin B.

[0090] The "non-flatting acrylic resin" involved in Tables 4 and 5 includes the following components in mass percentages: 60% of methyl methacrylate, 5% of phenyl methacrylate, and 35% of 2-hydroxyethyl acrylate.

[0091] Table 1

[0092]

[0093] Table 2

[0094]

[0095] Table 3

[0096]

[0097] Table 4

[0098]

[0099] Table 5

[0100]

[0101] Table 6

[0102]

[0103] Using the antireflection coating compositions provided in the above examples and comparative examples, the antireflection layers were prepared respectively, and the preparation process is as follows: The antireflection coating composition was spin-coated on a 4-inch substrate silicon wafer and baked on a hot plate at 200 °C for 60 s to complete curing and crosslinking, thereby forming an antireflection layer on the silicon wafer, and the whole was used as a test sample.

[0104] The properties of the prepared multiple antireflection layers were tested as follows:

[0105] (1) Using an ellipsometer, the n value, k value and film thickness of each antireflection layer were tested.

[0106] (2) Elution resistance verification: At a set temperature, each test sample was soaked in propylene glycol monomethyl ether (abbreviation: PM), propylene glycol monomethyl ether acetate (abbreviation: PMA), and ethyl lactate (abbreviation: EL) for 10 min respectively, then taken out and blown dry with an air gun.

[0107] (3) Aging test verification: Each test sample was stored at 50 °C for 15 days. On the 1st, 3rd, 5th, 9th, and 15th days, the n value, k value, film thickness, moisture, viscosity and particle size of each antireflection layer were tested respectively. The evaluation criterion is that if one test fails, it means the accelerated aging test fails; only when all indicators are normal, the aging test passes.

[0108] Judge the change range of the film thickness of each antireflection layer. The smaller the change range, the higher the differential solubility after curing of the current antireflection layer, it is not easy to dissolve in the basic solvent of the photoresist, and there is no mixing with the photoresist. The test results of the above properties are shown in the following tables. The results of the elution resistance verification are shown in Table 7 below.

[0109] Table 7

[0110]

[0111] In addition, in the embodiments of the present invention, the thermal decomposition temperature of the anti-reflection layer is greater than 250 °C, and the decomposition temperature of the catalyst is greater than 150 °C. Therefore, the baking temperature on the hot plate is 150 °C - 250 °C, further 190 °C - 210 °C. The temperature in this range is sufficient to completely cure the anti-reflection layer and obtain a stable anti-reflection layer. The above-mentioned elution resistance verification was carried out for the temperature of 160 °C. Hereinafter, in combination with Example 1, elution resistance verification tests were also carried out at 200 °C and 240 °C respectively. The test results are shown in Table 8.

[0112] Table 8

[0113]

[0114] The eluent obtained after the elution treatment in the elution resistance verification experiment at 160 °C (i.e., Table 7) was collected, and the absorbance of the eluent at a wavelength of 248 nm was measured using a UV spectrophotometer (UV). The test results are shown in Table 9. Among them, during the absorbance measurement, a blank solvent was used as a reference to observe whether there was an ultraviolet absorption peak other than the solvent. If there was an ultraviolet absorption peak other than the solvent, the elution experiment failed; if only the absorption peak of the solvent existed, the elution experiment passed.

[0115] Table 9

[0116]

[0117] Among them, the UV test curve of the PM eluent corresponding to Example 1 is shown in Figure 1 , as shown in the appendix Figure 1 . The PM eluent of Example 1 had no other absorption peaks, was consistent with the solvent, and there was no monomer or resin precipitation phenomenon.

[0118] In summary, through the above elution resistance verification, the anti-reflection coating obtained from the anti-reflection coating provided in the embodiments of the present invention has excellent cross-linking effect, no film loss after being soaked in the solvent, and a wide applicable baking temperature range.

[0119] Table 10

[0120]

[0121] The storage stability of the anti-reflection coating compositions provided in the above Examples 1-3 and Comparative Examples 1-3 was tested. One test method was to store the anti-reflection coating compositions in an environment of -15 °C - 40 °C for a certain period of time, and then test whether the relevant performance parameters of the anti-reflection coating compositions failed. Among them, the evaluation parameters included: n value, k value, moisture content, particle size, viscosity, etc.

[0122] During the evaluation process, if all parameters such as n, k, moisture content, particle size, and viscosity are normal, the shelf life is considered to pass the verification. If any one of them is unqualified, the verification is considered to fail. The test results are shown in Table 11.

[0123] Table 11

[0124]

[0125]

[0126] Another test method is to store the antireflection coating composition in an environment of -30°C for a certain period of time, and then test whether the relevant performance parameters of the antireflection coating composition fail. Among them, the evaluation parameters include: n value, k value, moisture content, particle size, viscosity, etc.

[0127] During the evaluation process, if all parameters such as n, k, moisture content, particle size, and viscosity are normal, the shelf life is considered to pass the verification. If any one of them is unqualified, the verification is considered to fail. The test results are shown in Table 12.

[0128] Table 12

[0129] Test sample -30℃ Example 1 Pass the 6-month shelf life Example 2 Pass the 6-month shelf life Example 3 Pass the 6-month shelf life Comparative example 1 Pass the 2-month shelf life Comparative example 2 Pass the 3-month shelf life Comparative example 3 Pass the 2-month shelf life

[0130] Test the etching rate ratio of the antireflection layer corresponding to the antireflection coating compositions provided in the above Examples 1-3 and Comparative Examples 1-3. The test method is to spin-coat the antireflection coating composition on the surface of a 4-inch silicon wafer substrate, bake it on a hot plate at 205°C for 60 s to complete curing and crosslinking, thereby forming an antireflection layer on the silicon wafer, and the whole is used as a test sample.

[0131] Use a reflection type film thickness meter to measure the film thickness of the antireflection layer, and use a plasma etching machine NLD-570 to perform dry etching for 15 s through a plasma with an O2 / Cl2 molar ratio of 1:9, and then measure the thickness of the etched antireflection layer again. The difference between the two is the etched film thickness. The test results are shown in Table 13. The etching rate ratio data in Table 13 are given relative to the I-line photoresist material (poly(p-hydroxystyrene)).

[0132] The calculation method of the etching rate ratio is the thickness of the etched antireflection layer / the thickness of the etched photoresist material under the same conditions. Judge the magnitude of the etching rate ratio of each antireflection layer. The larger the etching rate ratio, the better the rapid etching characteristics of the current antireflection layer, which can allow a shorter etching time, avoid excessive loss of the unexposed part of the photoresist film during the etching process, and enable the image to be completely transferred to the substrate, thereby obtaining a good photoresist pattern.

[0133] Table 13

[0134] Test sample Etch rate ratio Example 1 1.71 Example 2 1.72 Example 3 1.72 Comparative example 1 1.65 Comparative example 2 1.67 Comparative example 3 1.64

[0135] For the antireflection layers corresponding to the antireflection coating compositions provided in Examples 1-3, their etching rate ratios are significantly higher than those of Comparative Examples 1-3. This shows that under the same conditions, using the antireflection coatings provided in the embodiments of the present invention can improve production capacity.

[0136] For the antireflection layers corresponding to the antireflection coating compositions provided in Examples 1-3 and Comparative Examples 1-3, exposure tests were respectively carried out by matching the same type of photoresist. After exposure, the patterns were sliced, and the morphology was observed under an electron microscope. Specifically, the antireflection coating composition was spin-coated on the surface of a 4-inch silicon wafer substrate and baked on a hot plate at 205 °C for 60 s to complete curing and crosslinking, thereby forming an antireflection layer on the silicon wafer, and an ellipsometer was used to measure the coating thickness. Then, on the cured antireflection layer, the photoresist KX150 of Feikai Materials was coated at a speed of 1200 rpm and baked at 120 °C for 200 s. Subsequently, it was exposed using an I-line light source exposure machine at 300 mj / cm 2 ², developed with a 2.38% mass concentration of tetramethylammonium hydroxide (TMAH) developer for 70 seconds, and the obtained slices were observed for the morphology of the photoresist with a Hitachi scanning electron microscope SU8100. The results are shown in Table 14.

[0137] Table 14

[0138]

[0139]

[0140] Among them, the scanning electron microscope image of the test sample shown in Example 1 can be seen in Figure 2 . The test results show that after forming an antireflection layer using the antireflection coating composition provided in the embodiment of the present invention, the standing wave effect can be significantly eliminated.

[0141] Moreover, for the test sample shown in Example 1, a comparative example of using only the photoresist without using the antireflection layer was given as Comparative Example 4. The scanning electron microscope image of the test sample provided in Comparative Example 4 can be seen in Figure 3 . The test results show that if the antireflection coating composition provided in the embodiment of the present invention is not used and only the photoresist is arranged alone, there is an obvious standing wave effect.

[0142] The above is only for the convenience of those skilled in the art to understand the technical solutions of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An antireflection coating composition, characterized in that, The anti-reflection coating composition comprises the following components in mass percentages: 1 wt%-30 wt% of a matting resin system, 0.1 wt%-1.5 wt% of a catalyst, 0.2 wt%-1.5 wt% of a crosslinking agent, and 67 wt%-98.7 wt% of a solvent; The matting resin system comprises a first matting resin and a second matting resin, and the extinction coefficient k value of the first matting resin is greater than the extinction coefficient k value of the second matting resin; The compounding of the first matting resin and the second matting resin makes the extinction coefficient k value of the matting resin system be 0.4-0.

7.

2. The anti-reflection coating composition according to claim 1, wherein The extinction coefficient k value of the first matting resin ranges from 0.7 to 0.9; The extinction coefficient k value of the second matting resin ranges from 0.05 to 0.

2.

3. The anti-reflection coating composition according to claim 1, characterized in that, The first matting resin is prepared by a chemical grafting reaction of a first matrix resin and a first dyeing compound, wherein the molar percentage of the first dyeing compound in the reaction system is 20%-40%.

4. The anti-reflection coating composition according to claim 3, characterized in that, The first matrix resin is selected from at least one of acrylic resin, phenolic resin, epoxy resin, polyimide resin, and olefin resin; The first dyeing compound is selected from at least one of anthracene and its derivatives, coumarin and its derivatives, fluorescein and its derivatives, rhodamine, eosin, perylene and its derivatives, fluorene and its derivatives, and stilbene and its derivatives.

5. The anti-reflection coating composition according to claim 1, characterized in that, The second matting resin is prepared by a chemical grafting reaction of a second matrix resin and a second dyeing compound, wherein the molar percentage of the second dyeing compound in the reaction system is 5%-20%.

6. The anti-reflection coating composition according to claim 5, wherein The second matrix resin is selected from at least one of acrylic resin, phenolic resin, epoxy resin, polyimide resin, and olefin resin; The second dyeing compound is selected from at least one of anthracene and its derivatives, coumarin and its derivatives, fluorescein and its derivatives, rhodamine, eosin, perylene and its derivatives, fluorene and its derivatives, and stilbene and its derivatives.

7. The antireflection coating composition according to any one of claims 1-6, characterized in that, The catalyst is an organic acid salt catalyst; The organic acid salt catalyst includes at least one of p-toluenesulfonate, phenol sulfonate, dodecyl sulfonate, trifluoromethanesulfonic acid, naphthalene sulfonate, naphthalene disulfonate, quinoline-8-sulfonate, methanesulfonate, ethanesulfonate, butanesulfonate, oxalate, and camphor sulfonate.

8. The antireflection coating composition according to any one of claims 1-7, characterized in that, The crosslinking agent includes at least one of melamine-formaldehyde resin, glycoluril-formaldehyde resin, urea-formaldehyde resin, melamine resin, isocyanate, and glycoluril compound.

9. Use of the anti-reflection coating composition according to any one of claims 1-8 in a lithography process.

10. A coating structure, characterized in that, The coating structure includes: a substrate, a bottom anti-reflection layer, and a photoresist layer; The bottom anti-reflection layer is formed on the substrate by the anti-reflection coating composition according to any one of claims 1-8; The photoresist layer is formed on the bottom anti-reflection layer.

11. The coating structure according to claim 10, characterized in that, The bottom anti-reflection layer can absorb radiation with a wavelength of 100 nm-400 nm.

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