Chemically amplified positive photoresist and application thereof

Abstract

The invention discloses a chemically amplified positive photoresist and application thereof, and belongs to the technical field of photoetching materials. The chemical amplification type positive photoresist comprises the following components in percentage by mass: 5%-20% of polymer resin, 0.05%-1% of a photoacid generator, 0.001%-0.05% of an alkaline quencher, 100 ppm to 1000 ppm of a flatting agent and the balance of a solvent, wherein the polymer resin comprises a first copolymer and a second copolymer, and polymeric monomers of the first copolymer comprise polycycloalkyl protected methacrylate, long-chain alkyl protected methacrylate, alpha-oxygen-containing group protected methacrylate and methacrylic acid; and polymeric monomers of the second copolymer comprise hydroxystyrene, styrene and tert-butyl acrylate. According to the chemical amplification type positive photoresist, the chemical amplification type positive photoresist can keep better resolution and higher contrast ratio when being used under a light source with shorter wavelength.

Description

Technical Field

[0001] This application relates to the technical field of lithography materials, and particularly relates to a chemically amplified positive photoresist and its application. Background Art

[0002] Positive photoresists belong to the technical field of advanced semiconductor manufacturing materials and are widely used in the processing of fine graphic circuits in the optoelectronic information industry. They are key materials in the field of electronics manufacturing. After processes such as exposure, development, and etching, positive photoresists can transfer the patterns on the mask plate to the substrate, forming geometric patterns that exactly correspond to the mask plate.

[0003] Positive photoresists can be classified into two categories, chemically amplified and non-chemically amplified, according to chemical principles. Among them, chemically amplified positive photoresists include polymer resins, photoacid generators, additives, and solvents. Based on the principle that the acid generated by the photoacid generator under light irradiation catalyzes the chemical changes of acid-sensitive groups on the polymer resin, the performance amplification of the positive photoresist is realized, and it is widely used in the field of short-wavelength lithography.

[0004] Currently, the polymer resin of common chemically amplified positive photoresists is usually poly(p-hydroxystyrene) resin. However, such chemically amplified positive photoresists have strong absorption of lower-wavelength light sources, resulting in the disadvantage of low resolution (i.e., poor resolution) in the process using such light sources. Summary of the Invention

[0005] This application provides a chemically amplified positive photoresist and its application to solve the technical problems existing in the related art. The technical solutions include the following:

[0006] In a first aspect, this application provides a chemically amplified positive photoresist, which includes the following components in mass percentages: polymer resin 5%-20%, photoacid generator 0.05%-1%, basic quencher 0.01%-0.05%, leveling agent from 100 ppm to 1000 ppm, and the balance is solvent; wherein, the polymer resin includes a first copolymer and a second copolymer. The polymerization monomers of the first copolymer include: polycyclic alkyl-protected methacrylate, long-chain alkyl-protected methacrylate, α-oxygen group-protected methacrylate, and methacrylic acid. The polymerization monomers of the second copolymer include hydroxystyrene, styrene, and tert-butyl acrylate.

[0007] In some possible implementation manners, the polycyclic alkyl-protected methacrylate is selected from at least one of the following compounds:

[0008]

[0009] The long-chain alkyl group-protected methacrylate is selected from at least one of the following compounds:

[0010]

[0011] The α-oxygen-containing group-protected methacrylate is selected from at least one of the following compounds:

[0012]

[0013] In some possible embodiments, the polymerization monomers of the first copolymer satisfy the following molar percentages: polycyclic alkyl group-protected methacrylate compound, 10% - 30%; long-chain alkyl group-protected methacrylate compound, 5% - 25%; α-oxygen-containing group-protected methacrylate compound, 30% - 70%; methacrylic acid, 1% - 15%.

[0014] In some possible embodiments, the mass ratio of the first copolymer to the second copolymer is 1.5 - 9:1.

[0015] In some possible embodiments, the first copolymer satisfies at least one of the following physical property parameters: the weight-average molecular weight is 8K - 15K, and the molecular weight distribution coefficient PDI < 3.

[0016] In some possible embodiments, the polymerization monomers of the second copolymer satisfy the following molar percentages: hydroxy styrene compound, 60% - 70%; styrene compound, 10% - 30%; tert-butyl acrylate compound, 10% - 30%.

[0017] In some possible embodiments, the photoacid generator is a nonionic photoacid generator.

[0018] In some possible embodiments, the photoacid generator includes a first nonionic photoacid generator and a second nonionic photoacid generator; the first nonionic photoacid generator is selected from at least one of the following compounds:

[0019]

[0020]

[0021] The structure of the second nonionic photoacid generator is shown as follows:

[0022]

[0023] Among them, R is selected from one of the following structures:

[0024]

[0025] In some possible embodiments, the basic quencher is selected from aliphatic amine quenchers.

[0026] In some possible embodiments, the aliphatic amine quencher is selected from at least one of monoalkylamine, dialkylamine, trialkylamine, alkanolamine, and tetramethylammonium hydroxide.

[0027] In a second aspect, the present application provides a method for preparing a chemically amplified positive photoresist as described in the first aspect of the present application, comprising the following steps: Step 1: Mix a first copolymer and a second copolymer to obtain a polymer resin. Among them, the polymerization monomers of the first copolymer may include, for example: polycyclic alkyl-protected methacrylate, long-chain alkyl-protected methacrylate, α-oxygen group-protected methacrylate, and methacrylic acid; the polymerization monomers of the second copolymer include, for example, hydroxystyrene, styrene, and tert-butyl acrylate; Step 2: Mix the following components in mass percentages: 5%-20% of the polymer resin, 0.05%-1% of the photoacid generator, 0.01%-0.05% of the basic quencher, 100 ppm-1000 ppm of the leveling agent, and the solvent makes up the mass percentage to obtain the chemically amplified positive photoresist described in the present application.

[0028] In a third aspect, the present application provides an application of the chemically amplified positive photoresist as described in the first aspect of the present application in a lithography process, comprising the following steps: Step 1: Uniformly apply the chemically amplified positive photoresist provided by the present application on a surface-modified silicon wafer; Step 2: Soft bake the silicon wafer coated with the chemically amplified positive photoresist; Step 3: Expose the soft-baked silicon wafer using a projection exposure machine; Step 4: Post-bake the exposed silicon wafer; Step 5: Develop the post-baked silicon wafer using a developer.

[0029] The beneficial effects of the technical solution provided by the present application at least include:

[0030] The chemically amplified positive photoresist provided by the embodiments of the present application uses a combination of a first copolymer and a second copolymer as the polymer resin. Among them, the polymerization monomers of the first copolymer include: polycyclic alkyl group-protected methacrylate, long-chain alkyl group-protected methacrylate, α-oxygen-containing group-protected methacrylate, and methacrylic acid, so that the first copolymer is a polyacrylate resin. The polymerization monomers of the second copolymer include hydroxystyrene, styrene, and tert-butyl acrylate, so that the second copolymer is a poly(p-hydroxystyrene) resin. The two cooperate with each other to effectively utilize the optical property of the polyacrylate resin being transparent to short-wavelength light sources on the basis of meeting the basic performance of the chemically amplified positive photoresist, enhance the transparency of the chemically amplified positive photoresist to short-wavelength light sources, thereby improving the resolution of the chemically amplified positive photoresist during the process under such light sources, and achieving good resolution, high contrast, and small line width roughness of the lithography pattern. Detailed implementation manners

[0031] In view of this, the present application discloses a chemically amplified positive photoresist and its application, designs a series of acrylic resins, utilizes the optical property of the acrylic resins being transparent to short-wavelength light sources, and by jointly using the acrylic resins and poly(p-hydroxystyrene) resins as the resins of the chemically amplified positive photoresist and cooperating with other additives, enables the raw materials of the chemically amplified positive photoresist to be organically coordinated, and the developed pattern has small line width roughness, good resolution, and high contrast.

[0032] The first aspect of the present application discloses a chemically amplified positive photoresist, and the chemically amplified positive photoresist includes the following components in mass percentages:

[0033] Polymer resin 5%-20%, photoacid generator 0.05%-1%, basic quencher 0.01%-0.05%, leveling agent 100 ppm - 1000 ppm, and the solvent is the balance.

[0034] Among them, the polymer resin may include, for example, a first copolymer and a second copolymer. The polymerization monomers of the first copolymer may include, for example: polycyclic alkyl group-protected methacrylate, long-chain alkyl group-protected methacrylate, α-oxygen-containing group-protected methacrylate, and methacrylic acid. The polymerization monomers of the second copolymer include, for example, hydroxystyrene, styrene, and tert-butyl acrylate.

[0035] The chemically amplified positive photoresist provided by the embodiments of the present application uses a combination of a first copolymer and a second copolymer as the polymer resin. Among them, the polymerization monomers of the first copolymer include: polycyclic alkyl group-protected methacrylate, long-chain alkyl group-protected methacrylate, α-oxygen-containing group-protected methacrylate, and methacrylic acid, so that the first copolymer is a polyacrylate resin. The polymerization monomers of the second copolymer include hydroxystyrene, styrene, and tert-butyl acrylate, so that the second copolymer is a poly(p-hydroxystyrene) resin. The two cooperate to effectively utilize the optical property that the polyacrylate resin is transparent to short-wavelength light sources on the basis of meeting the basic performance of the chemically amplified positive photoresist, enhance the transparency of the chemically amplified positive photoresist to short-wavelength light sources, thereby improving the resolution of the chemically amplified positive photoresist during the manufacturing process under such light sources, and achieving good resolution, high contrast, and small line width roughness of the photolithography pattern.

[0036] In some embodiments, the polycyclic alkyl group-protected methacrylate can be selected from at least one of the following compounds:

[0037]

[0038]

[0039] The long-chain alkyl group-protected methacrylate can be selected from at least one of the following compounds:

[0040]

[0041] The α-oxygen-containing group-protected methacrylate can be selected from at least one of the following compounds:

[0042]

[0043] In some embodiments, the polymerization monomers of the first copolymer may satisfy the following molar percentages, for example. The molar percentage of the polycyclic alkyl-protected methacrylate compound may include, for example, 10% to 30%, specifically including but not limited to 10%, 12%, 14%, 16%, 18%, 20%, 30%, etc.; the molar percentage of the long-chain alkyl-protected methacrylate compound may include, for example, 5% to 25%, specifically including but not limited to 5%, 7%, 9%, 11%, 13%, 15%, 17%, 19%, 20%, 25%, etc.; the molar percentage of the α-oxygen-containing group-protected methacrylate compound may include, for example, 30% - 70%, specifically including but not limited to 30%, 40%, 50%, 55%, 60%, 65%, 70%, etc.; the molar percentage of methacrylic acid may include, for example, 1% - 15%, specifically including but not limited to 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, etc.

[0044] In some embodiments, the first copolymer may satisfy at least one of the following physical property parameters, for example: the weight-average molecular weight is 8K - 15K, specifically it may be 8K, 9K, 10K, 11K, 12K, 13K, 14K, 15K, etc., or other values within the above range; the polydispersity index PDI of the molecular weight distribution is < 3, specifically it may be 2.8, 2.6, 2.4, 2.2, 2, 1.8, 1.6, 1.4, 1.2, 1, etc., or other values within the above range.

[0045] In one of the embodiments, the polymerization monomers of the first copolymer may include isobornyl methacrylate, n-butyl methacrylate, γ-butyrolactone methacrylate, and methacrylic acid; the molar percentages of the polymerization monomers of the first copolymer may include: 15% of isobornyl methacrylate, 10% of n-butyl methacrylate, 65% of γ-butyrolactone methacrylate, and 10% of methacrylic acid; the weight-average molecular weight of the first copolymer may be, for example, 10501 g / mol; the polydispersity index PDI of the first copolymer may be, for example, 2.22.

[0046] In some embodiments, the polymerization monomers of the second copolymer may, for example, satisfy the following molar percentages: the molar percentage of the hydroxy styrene compound may be, for example, 60% to 70%, specifically 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, etc., or other values within the above range; the molar percentage of the styrene compound may be, for example, 10% to 30%, specifically 10%, 15%, 20%, 25%, 30%, etc., or other values within the above range; the molar percentage of the tert-butyl acrylate compound may be, for example, 10% - 30%, specifically 10%, 15%, 20%, 25%, 30%, etc., or other values within the above range.

[0047] In some embodiments, the second copolymer may, for example, satisfy at least one of the following physical property parameters: the weight-average molecular weight is 8K - 15K, specifically 8K, 9K, 10K, 11K, 12K, 13K, 14K, 15K, etc., or other values within the above range; the molecular weight distribution coefficient PDI < 3, specifically 2.8, 2.6, 2.4, 2.2, 2, 1.8, 1.6, 1.4, 1.2, 1, etc., or other values within the above range.

[0048] In one of the embodiments, the polymerization monomers of the second copolymer may, for example, include p-hydroxy styrene, styrene, and tert-butyl acrylate; the molar percentages of the polymerization monomers of the second copolymer may, for example, include: 15% of p-hydroxy styrene, 65% of styrene, and 20% of tert-butyl acrylate; the weight-average molecular weight of the second copolymer may be, for example, 11000 g / mol; the molecular weight distribution coefficient PDI of the first copolymer may be, for example, 1.81.

[0049] In some embodiments, the mass ratio of the polymer resin of the first copolymer and the second copolymer may be, for example, 1.5 - 9:1, specifically 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 2.5:1, 1.5:1, etc., or other situations within the above range.

[0050] In some embodiments, the photoacid generator may include, for example, a first nonionic photoacid generator and a second nonionic photoacid generator. Among them, the mass fraction of the first nonionic photoacid generator may include, for example, 10%-90%, specifically but not limited to 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc.; the mass fraction of the second nonionic photoacid generator may include, for example, 10%-90%, specifically but not limited to 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc. By providing two different nonionic photoacid generators in the embodiments of the present application, acids with different structures can be generated after the chemically amplified positive photoresist is exposed. While maintaining high exposure sensitivity, the diffusion distance of the photoacid can also be shortened, thereby improving the resolution of the chemically amplified positive photoresist.

[0051] In some embodiments, the first nonionic photoacid generator may be selected from at least one of the following compounds:

[0052]

[0053]

[0054] In some embodiments, the structure of the second nonionic photoacid generator is shown as follows:

[0055]

[0056] Among them, R may be selected from one of the following structures:

[0057]

[0058] In some embodiments, the basic quencher may be selected from aliphatic amine quenchers, for example; further, the aliphatic amine quenchers may be selected from at least one of monoalkylamines, dialkylamines, trialkylamines, alkanolamines, and tetramethylammonium hydroxide; still further, the basic quencher may be selected from aliphatic amine quenchers having 12 or fewer carbon atoms. In some embodiments, the monoalkylamine may include, but is not limited to, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; the dialkylamine may include, but is not limited to, diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; the trialkylamine may include, but is not limited to, trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; the alkanolamine may include, but is not limited to, diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine, etc.

[0059] In some embodiments, the leveling agent may be selected from at least one of 3M fluorocarbon surfactant FC-4430 and Troy Troysol S366.

[0060] In some embodiments, the solvent may be selected from at least one of propylene glycol methyl ether acetate, propylene glycol methyl ether, ethyl lactate, anisole, propylene glycol monoacetate, propylene glycol monoethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol methyl ethyl ether, butyl acetate, neopentyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, diacetone alcohol, or γ-butyrolactone.

[0061] The second aspect of the present application provides a method for preparing the chemically amplified positive photoresist as described above, comprising the following steps:

[0062] Step 1: Mix the first copolymer and the second copolymer to obtain a polymer resin. Among them, the polymerization monomers of the first copolymer may include, for example: polycyclic alkyl-protected methacrylate, long-chain alkyl-protected methacrylate, α-oxygen group-protected methacrylate, and methacrylic acid. The polymerization monomers of the second copolymer include, for example, hydroxystyrene, styrene, and tert-butyl acrylate.

[0063] In some embodiments, the preparation process of the first copolymer may include the following steps: (1) At room temperature, isobornyl methacrylate, n-butyl methacrylate, γ-butyrolactone methacrylate, methacrylic acid, and azobisisobutyronitrile are dissolved in propylene glycol methyl ether acetate to obtain a first mixed solution. (2) Under the protection of a nitrogen atmosphere, the first mixed solution is heated to 70 °C and reacted for 8 h. (3) The reacted first mixed solution is cooled to room temperature, and the cooled first mixed solution is precipitated by the methanol precipitation method. The obtained precipitate is washed and dried to obtain a solid sample of the first copolymer.

[0064] In some embodiments, the first mixed solution may include, for example: 33.35 g of isobornyl methacrylate, 14.22 g of n-butyl acrylate, 110.61 g of γ-butyrolactone methacrylate, 8.61 g of methacrylic acid, 3.5 g of azobisisobutyronitrile, and 70 g of propylene glycol methyl ether acetate.

[0065] In some embodiments, the preparation process of the second copolymer may include the following steps: (1) Take a 500 mL four-necked flask, continuously introduce dry N2, start stirring, and use a peristaltic pump to add 200 g of dry tetrahydrofuran solvent to the reaction flask, and then cool the reaction flask using a liquid nitrogen / ethanol bath. (2) When the temperature drops to -40 °C, use a syringe to take 0.9 mL of a hexane solution of n-butyllithium (concentration 1.3 M) and add it to the reaction flask. Continue to cool to -70 °C to -80 °C, and use a peristaltic pump with a feeding tube with a diameter of 10 mm to sequentially dropwise add 67.7 g of styrene, 18 g of p-hydroxystyrene, and 25.63 g of tert-butyl acrylate into the reaction flask at a flow rate of 60 drops / min to obtain a second mixed solution. (3) Maintain the temperature at -70 °C to -80 °C, continue to react for 1 h, and then add deoxygenated methanol to the reaction flask to terminate the reaction. (4) The second mixed solution after the termination of the reaction is precipitated by the methanol precipitation method. The obtained precipitate is washed and dried to obtain the protected polymer of the second copolymer. (5) Using acetone as a solvent, the protected polymer is deprotected with hydrobromic acid, and then the deprotected protected polymer is precipitated with water, filtered, and dried to obtain a solid sample of the monodisperse second copolymer.

[0066] Step two: Mix the following components in mass percentages: 5% - 20% of polymer resin, 0.05% - 1% of photoacid generator, 0.01% - 0.05% of basic quencher, 100 ppm - 1000 ppm of leveling agent, and the solvent makes up the mass percentage to obtain the chemically amplified positive photoresist of the present application.

[0067] In some embodiments, the chemically amplified positive photoresist obtained in Step 2 can also be subjected to a filtration process. For example, the chemically amplified positive photoresist obtained in Step 2 can be filtered through a fluororesin filter with a pore size of 0.2 μm.

[0068] The third aspect of the present application provides an application of the chemically amplified positive photoresist as described above in a lithography process, including the following steps:

[0069] Step 1: Uniformly apply the chemically amplified positive photoresist provided in the present application onto a substrate. For example, the substrate can be a surface-modified silicon wafer.

[0070] Step 2: Soft bake the silicon wafer coated with the chemically amplified positive photoresist.

[0071] In some embodiments, the temperature of the soft bake can, for example, include 105°C - 115°C, and further can be 110°C; the time of the soft bake can, for example, include 80 s - 100 s, and further can be 90 s.

[0072] Step 3: Expose the soft-baked silicon wafer using a projection exposure machine.

[0073] Step 4: Post-bake the exposed silicon wafer.

[0074] In some embodiments, the temperature of the post-bake can, for example, include 95°C - 105°C, and further can be 100°C; the time of the post-bake can, for example, include 115 s - 125 s, and further can be 120 s.

[0075] Step 5: Develop the post-baked silicon wafer using a developer.

[0076] Among them, the chemically amplified positive photoresist provided in the embodiments of the present application can be suitable for exposure under a short-wavelength light source, such as a light source with a wavelength of 193 nm or shorter, while avoiding absorption under such a light source, so that the resolution of the process under such a light source is relatively high.

[0077] In some embodiments, the developer can, for example, include an aqueous solution of tetramethylammonium hydroxide with a concentration of 2.38%.

[0078] The exemplary embodiments of the present invention will be described in more detail below. Although the exemplary embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. For those where specific techniques or conditions are not indicated in the examples, they shall be carried out according to the techniques or conditions described in the literature in the art or according to the product specifications. For reagents or instruments whose manufacturers are not indicated, they are all conventional products that can be obtained through commercial procurement.

[0079] Example 1

[0080] Example 1 provides a chemically amplified positive photoresist, and its formulation is as follows: 20 wt% of a polymer resin, 0.4 wt% of a photoacid generator, 0.008 wt% of triethanolamine, 200 ppm of FC-443, and the balance is propylene glycol monomethyl ether acetate. Among them, the composition of the polymer resin is shown in Table 1.

[0081] The first copolymer involved in the chemically amplified positive photoresist was prepared by the following method: At room temperature, 33.35 g of isobornyl methacrylate, 14.2 g of n-butyl methacrylate, 110.61 g of γ-butyrolactone methacrylate, 8.61 g of methacrylic acid, and 3.5 g of azobisisobutyronitrile were dissolved in 70 g of propylene glycol monomethyl ether acetate to obtain a first mixed solution; then, under the protection of a nitrogen atmosphere, the first mixed solution was heated to 70 °C and reacted for 8 h; then, the reacted first mixed solution was cooled to room temperature, and the cooled first mixed solution was precipitated by the methanol precipitation method, and the obtained precipitate was washed and dried to obtain a first copolymer, denoted as PA-1. The weight-average molecular weight of PA-1 was 10501 g / mol, and the PDI was 2.22.

[0082] The second copolymer involved in the chemically amplified positive photoresist was prepared by the following method: A 500 mL four-necked flask was taken, and dry N2 was continuously introduced, and stirring was started. 200 g of dry tetrahydrofuran solvent was added to the reaction flask by a peristaltic pump, and then the reaction flask was cooled by a liquid nitrogen / ethanol bath; when the temperature dropped to -40 °C, 0.9 mL of a hexane solution of n-butyllithium (concentration: 1.3 M) was taken by a syringe and added to the reaction flask, and the temperature was further lowered to -70 °C to -80 °C. By a peristaltic pump, with a feeding tube with a diameter of 10 mm, 67.7 g of styrene, 18 g of p-hydroxystyrene, and 25.63 g of tert-butyl acrylate were sequentially added dropwise to the reaction flask at a flow rate of 60 drops / min to obtain a second mixed solution; then, the temperature was maintained at -70 °C to -80 °C, and after continuing the reaction for 1 h, methanol that had been deoxygenated was added to the reaction flask to terminate the reaction; then, the second mixed solution after the termination of the reaction was precipitated by the methanol precipitation method, and the obtained precipitate was washed and dried to obtain a protected polymer of the second copolymer; then, using acetone as a solvent, the protected polymer was deprotected with hydrobromic acid, and then the deprotected protected polymer was precipitated with water, filtered, and dried to obtain a monodisperse second copolymer, denoted as PA-2. The weight-average molecular weight of PA-2 was 11000 g / mol, and the PDI was 1.81.

[0083] Step 1: Mix the first copolymer and the second copolymer to obtain a polymer resin. The mass fractions of the first copolymer and the second copolymer in the polymer resin are shown in Table 1 in detail.

[0084] Step 2: Dissolve 20 wt% of polymer resin, 0.4 wt% of photoacid generator, 0.008 wt% of triethanolamine, and 200 ppm of FC-443 in propylene glycol monomethyl ether acetate (the mass fraction of propylene glycol monomethyl ether acetate is the balance), and then filter it using a fluororesin filter with a pore size of 0.2 μm to obtain a chemically amplified positive photoresist. For the types of photoacid generators, see Table 1 for details.

[0085] Example 2

[0086] The difference between this Example 2 and Example 1 is that the mass fractions of the first copolymer and the second copolymer in the polymer resin in step (1) are different (see Table 1 for details).

[0087] Example 3

[0088] The difference between this Example 3 and Example 1 is that the mass fractions of the first copolymer and the second copolymer in the polymer resin in step (1) are different (see Table 1 for details).

[0089] Example 4

[0090] The difference between this Example 4 and Example 1 is that the mass fractions of the first copolymer and the second copolymer in the polymer resin in step (1) are different (see Table 1 for details).

[0091] Example 5

[0092] The difference between this Example 5 and Example 2 is that the proportion of the photoacid generator in step (2) is different (see Table 1 for details).

[0093] Example 6

[0094] The difference between this Example 6 and Example 2 is that the proportion of the photoacid generator in step (2) is different (see Table 1 for details).

[0095] Comparative Example 1

[0096] The difference between this Comparative Example 1 and Example 1 is that the mass fractions of the first copolymer and the second copolymer in the polymer resin in step (1) are different (see Table 1 for details).

[0097] Comparative Example 2

[0098] The difference between this Comparative Example 2 and Example 1 is that the mass fractions of the first copolymer and the second copolymer in the polymer resin in step (1) are different (see Table 1 for details).

[0099] Comparative Example 3

[0100] The difference between this Comparative Example 3 and Example 2 is that the type of the photoacid generator in step (2) is different (see Table 1 for details).

[0101] Comparative Example 4

[0102] The difference between this Comparative Example 4 and Example 2 lies in that the types of photoacid generators in step (2) are different (see Table 1 for details).

[0103] The composition of the polymer resin in the chemically amplified positive photoresist involved in the above examples and comparative examples can be seen in Table 1.

[0104] Table 1

[0105]

[0106]

[0107]

[0108] Test Example

[0109] Using the chemically amplified positive photoresists of the above Examples 1 - 6 and Comparative Examples 1 - 4 for lithography operations, the operation process is as follows: The chemically amplified positive photoresist is spin-coated on a silicon wafer treated with hexamethyldisilazane and heated on a hot plate at 110°C for 90 seconds so that the film thickness of the dried chemically amplified positive photoresist is 8 μm. Then, a projection exposure machine with an exposure wavelength of 365 (i-line) ["NSR - 2005i9C", produced by Nikon Crop., NA = 0.57, σ = 0.8] is used for exposure, and the exposure amount is gradually changed simultaneously. After exposure, the silicon wafer is heated on a hot plate at 100°C for 120 seconds, and then single-wafer development is carried out using a 2.38% aqueous solution of tetramethylammonium hydroxide.

[0110] The developed patterns are observed using a scanning electron microscope, and the following parameters are measured. The test results are shown in Table 2.

[0111] Effective photosensitivity: Represented by the exposure amount for 1.0 μm line and 1:1 line and space;

[0112] Resolution: The minimum size for distinguishing lines and spaces at the exposure amount of effective photosensitivity.

[0113] Table 2

[0114] NO. <![CDATA[Effective photosensitivity [mj / cm 2 > Resolution [μm] Example 1 41 2.2 Example 2 80 0.9 Example 3 129 1.4 Example 4 187 1.9 Example 5 102 1.1 Example 6 179 1.3 Comparative Example 1 40 3.5 Comparative Example 2 300 2.8 Comparative Example 3 90 2.1 Comparative Example 4 129 2.5

[0115] As can be seen from Table 2, when the polymer resin in the chemically amplified positive photoresist only includes the first copolymer, the resolution of the chemically amplified positive photoresist is poor; when the polymer resin in the chemically amplified positive photoresist only includes the second copolymer, both the effective photosensitivity and resolution of the chemically amplified positive photoresist are poor.

[0116] The present application prepares a chemically amplified positive photoresist by simultaneously using a first copolymer and a second copolymer, so that the chemically amplified positive photoresist can obtain good line profiles while maintaining high resolution.

[0117] In the embodiments of the present application, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. The term "plurality" means two or more, unless otherwise clearly defined.

[0118] The above description is only for the convenience of those skilled in the art to understand the technical solution of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the principle of the present application shall be included within the protection scope of the present application.

Claims

1. A chemically amplified positive photoresist, characterized in that, The chemically amplified positive photoresist comprises the following components in mass percentages: Polymer resin 5%-20%, photoacid generator 0.05%-1%, basic quencher 0.01%-0.05%, leveling agent 100 ppm-1000 ppm, and the solvent is the balance; wherein, The polymer resin comprises a first copolymer and a second copolymer. The polymerization monomers of the first copolymer include: polycyclic alkyl group-protected methacrylate, long-chain alkyl group-protected methacrylate, α-oxygen-containing group-protected methacrylate, and methacrylic acid. The polymerization monomers of the second copolymer include hydroxystyrene, styrene, and tert-butyl acrylate.

2. The chemically amplified positive photoresist according to claim 1, wherein The polycyclic alkyl group-protected methacrylate is selected from at least one of the following compounds: The long-chain alkyl group-protected methacrylate is selected from at least one of the following compounds: The α-oxygen-containing group-protected methacrylate is selected from at least one of the following compounds:

3. The chemically amplified positive photoresist according to claim 2, wherein The polymerization monomers of the first copolymer satisfy the following molar percentages:

4. The chemically amplified positive photoresist according to claim 1, characterized in that, The mass ratio of the first copolymer to the second copolymer is 1.5-9:

1.

5. The chemically amplified positive photoresist according to claim 1, wherein The first copolymer satisfies at least one of the following physical property parameters: the weight-average molecular weight is 8K-15K, and the molecular weight distribution coefficient PDI < 3.

6. The chemically amplified positive photoresist according to claim 1, wherein The polymerization monomers of the second copolymer satisfy the following molar percentages: Hydroxystyrene compound 60% - 70% Styrene compound 10% - 30% Tert-butyl acrylate compound 10% - 30%.

7. The chemically amplified positive photoresist according to claim 1, wherein The photoacid generator is a non-ionic photoacid generator.

8. The chemically amplified positive photoresist according to claim 7, wherein The photoacid generator comprises a first non-ionic photoacid generator and a second non-ionic photoacid generator; The first non-ionic photoacid generator is selected from at least one of the following compounds: The structure of the second non-ionic photoacid generator is shown as follows: Wherein, R is selected from one of the following structures:

9. The chemically amplified positive photoresist according to claim 1, wherein The basic quencher is selected from aliphatic amine quenchers.

10. The chemically amplified positive photoresist according to claim 9, wherein The aliphatic amine quenchers are selected from at least one of monoalkylamine, dialkylamine, trialkylamine, alkanolamine, and tetramethylammonium hydroxide.

11. Use of the chemically amplified positive photoresist according to any one of claims 1-10 in a lithography process.

Images