JP7583603B2 - Resin composition - Google Patents

Description

This disclosure relates to a resin composition, and in particular to a resin composition for use as a resist for ultraviolet laser processing.

Dicing is used to separate semiconductor wafers into individual devices. Dicing is typically performed by scribing or sawing. In recent years, plasma dicing, which uses plasma to etch specific parts of the wafer, has been attracting attention.

During plasma dicing, a mask made of a resist film is formed on the wafer, and the parts of the wafer exposed through the mask are then plasma etched to separate them into individual devices. The mask must be able to accurately form the pattern for etching, and also be able to protect the elements on the wafer from the plasma.

The mask can be formed by patterning a photoresist film using standard lithography operations. However, this method poses a problem in terms of the cost of mask formation. It has also been considered to form a mask by directly patterning a resist film made of polyvinyl alcohol (PVA) instead of a photoresist film using an ultraviolet (UV) laser (see, for example, Patent Document 1).

JP 2010-165963 A

Conventional resist films made of PVA and the like have poor heat resistance and low UV laser absorption, which means that it is not possible to increase the processing speed and it is difficult to perform high-precision processing. Adding an ultraviolet absorber to the resist film has also been considered, but increasing the amount added causes the ultraviolet absorber to precipitate, making it impossible to sufficiently improve the UV laser absorption. Furthermore, adding an ultraviolet absorber does not solve the problem of the resist film's low heat resistance.

Furthermore, to protect the elements on the wafer from plasma, the resist film needs to be sufficiently thick, but with conventional resist films made of PVA, increasing the thickness of the film further reduces processability, making it difficult to make the film sufficiently thick.

The present disclosure aims to realize an ultraviolet laser processing resist that can be processed at high speed and with high precision.

One embodiment of the resin composition for ultraviolet laser processing resist of the present disclosure contains an ultraviolet absorbing copolymer having a first block made of a first polysilane and a second block which is a copolymer of a vinyl monomer and contains ultraviolet absorbing monomer units derived from an ultraviolet absorbing monomer having ultraviolet absorbing properties, and a second polysilane having a molecular weight larger than that of the first polysilane.

In one embodiment of the resin composition for ultraviolet laser processing resist, the weight average molecular weight of the second polysilane is 10,000 or more and 50,000 or less, and the proportion of the second polysilane can be 5 parts by mass or more and less than 45 parts by mass per 100 parts by mass of the ultraviolet absorbing copolymer.

In one embodiment of a resin composition for a UV laser processing resist, the UV absorbing monomer can have any one of a benzotriazole skeleton, a benzophenone skeleton, and a triazine skeleton.

In one embodiment of the resin composition for ultraviolet laser processing resist, the proportion of the ultraviolet absorbing monomer unit in the entire ultraviolet absorbing copolymer can be 3% by mass or more and 70% by mass or less, and the proportion of the first polysilane in the entire ultraviolet absorbing copolymer can be 30% by mass or more and 97% by mass or less.

In one embodiment of the resin composition for ultraviolet laser processing resist, the ultraviolet transmittance at a wavelength of 355 nm can be 2% or less.

The resist agent of the present disclosure contains the resin composition of the present disclosure and a solvent.

The resin composition disclosed herein makes it possible to realize an ultraviolet laser processing resist that can be processed at high speed and with high precision.

The resist agent of this embodiment contains a resin composition (resist polymer) and a solvent. The resist agent of this embodiment can be directly patterned by an ultraviolet (UV) laser, and can be used, for example, to form a mask for plasma dicing. The resist polymer contained in the resist agent of this embodiment contains an ultraviolet absorbing copolymer having an ultraviolet absorbing effect, which contains a first polysilane, and a second polysilane.

The ultraviolet absorbing copolymer of this embodiment has a first block made of a first polysilane and a second block made of a polymer of a vinyl monomer and having ultraviolet absorbing properties.

The first block is made of a first polysilane, has a main chain formed by silicon-silicon bonds, and has an organic substituent on the side chain. The main chain formed by silicon-silicon bonds may be linear or branched, or may have a ring structure. The organic substituent on the side chain is not particularly limited, and may be preferably an alkyl group, an aryl group, an aralkyl group, or the like. The alkyl group may be linear or branched, or may have a ring structure. It may also be an organic substituent containing a heteroatom. The molecular weight of the polysilane that is the first block is not particularly limited, but from the viewpoint of handleability as a resist agent, the number average molecular weight (Mn) is preferably 500 or more, more preferably 800 or more, and preferably 3000 or less, more preferably 2500 or less. The weight average molecular weight (Mw) is preferably 800 or more, more preferably 1000 or more, and preferably 4000 or less, more preferably 3000 or less.

The second block is made of a polymer of a vinyl monomer, and at least a part of the monomer units constituting the second block is an ultraviolet absorbing monomer unit derived from an ultraviolet absorbing monomer having an ultraviolet absorbing group. Therefore, the second block has an ultraviolet absorbing effect. The ultraviolet absorbing group is not particularly limited, but can be, for example, a benzotriazole skeleton, a benzophenone skeleton, or a triazine skeleton. The ultraviolet absorbing monomer only needs to have a vinyl group and an ultraviolet absorbing group, but from the viewpoint of polymerization, etc., an acrylic monomer that is a derivative of an acrylic acid ester (acrylate) or a derivative of a methacrylic acid ester (methacrylate) is preferable. Specifically, as the ultraviolet absorbing monomer, 3-(2H-benzotriazol-2-yl)-4-hydroxyphenethyl=methacrylate, 2-(4-benzoyl-3-hydroxyphenoxy)ethyl acrylate, or 2-[4-(4,6-diphenyl)-[1,3,5]triazin-2-yl]-3-hydroxy-phenoxy}-ethylprop-2-enoate, etc. can be used. In the following, acrylate or methacrylate will be referred to as (meth)acrylate.

The ultraviolet absorbing copolymer containing the first block and the second block can be prepared by mixing and reacting the first polysilane with the ultraviolet absorbing monomer. By irradiating the first polysilane with ultraviolet light, etc., radicals can be generated, so that the ultraviolet absorbing monomer can be copolymerized with the first polysilane.

The proportion of the first block in the entire ultraviolet absorbing copolymer is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 60% by mass or more, from the viewpoint of heat resistance. Also, from the viewpoint of exerting an ultraviolet absorbing effect, it is preferably 97% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.

The proportion of monomer units derived from ultraviolet absorbing monomers in the entire ultraviolet absorbing copolymer is preferably 3% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and even more preferably 15% by mass or more, from the viewpoint of exerting an ultraviolet absorbing effect. Also, from the viewpoint of heat resistance, it is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 40% by mass or less.

The UV-absorbing copolymer may contain monomer units derived from UV-non-absorbing monomers that do not have a UV-absorbing group such as a benzotriazole skeleton and do not exhibit UV-absorbing properties. The UV-non-absorbing monomer is not particularly limited, but may be an acrylic monomer such as a (meth)acrylic acid ester or a (meth)acrylamide derivative. By adding a (meth)acrylic acid alkyl ester having an alkyl group with 4 or more carbon atoms, the resist film can be made flexible, improving adhesion to the wafer and further improving processability. In addition, by adding a hydrocarbon monomer that has a higher plasma etching resistance than polysilane, the plasma resistance of the resist film can be improved.

The non-UV absorbing monomer can be copolymerized with the UV absorbing monomer to form a constituent unit of the second block. It may also be included in the UV absorbing copolymer as a constituent unit of a block different from the second block.

The proportion of monomer units derived from non-UV-absorbing monomers in the entire UV-absorbing copolymer is preferably 15% by mass or less, and more preferably 10% by mass or less.

The ratio of the first block, the second block, and each monomer unit is based on the amount charged when polymerizing the ultraviolet absorbing copolymer, but can also be determined by composition analysis of the ultraviolet absorbing copolymer.

The second polysilane to be mixed with the ultraviolet absorbing copolymer has a higher molecular weight than the first polysilane constituting the first block. Specifically, the weight average molecular weight (Mw) of the second polysilane is preferably 10,000 or more, more preferably 11,000 or more, from the viewpoint of improving the heat resistance and film strength of the resist agent. Also, from the viewpoint of the coatability (coating liquid viscosity) of the resist agent, it is preferably 50,000 or less, more preferably 20,000 or less.

By adding a second polysilane with a higher molecular weight than the first polysilane, the heat resistance and film strength of the resist film when formed can be improved. This improves the crack resistance of the resist film and its adhesion to the film formation surface. Even when a relatively thick resist film is formed, high-speed processing can be performed.

When a resist film using the resist polymer of this embodiment is laser processed, the processing speed can be made faster than 600 mm/s, and good processing can be achieved even at 700 mm/s or 800 mm/s, and sufficient processability is demonstrated up to about 1000 mm/s. Laser processing at processing speeds of 600 mm/s or less is also possible.

In the resist polymer of this embodiment, the ratio of the second polysilane to 100 parts by mass of the ultraviolet absorbing copolymer is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, from the viewpoint of heat resistance and film strength, and is preferably 45 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 35 parts by mass or less, from the viewpoint of coatability.

The resist agent of this embodiment can be prepared by dissolving the ultraviolet absorbing copolymer and the second polysilane in a solvent. It can also be prepared by mixing a solution in which the ultraviolet absorbing copolymer is dissolved and a solution in which the second polysilane is dissolved.

The solvent is not particularly limited as long as it can dissolve the resist polymer, but may be, for example, toluene, tetrahydrofuran, methyl ethyl ketone, propylene glycol monomethyl ether acetate, cyclohexanone, etc. The solvent may be a mixed solvent containing multiple solvents.

The proportion of resist polymer in the entire resist agent can be adjusted depending on the thickness of the resist film to be formed, but is preferably 10% by mass or more, more preferably 25% by mass or more, and preferably 70% by mass or less, more preferably 60% by mass or less.

The resist agent does not need to contain any components other than the resist polymer and the solvent, but may contain other components. Examples of other components include additive components such as leveling agents, light stabilizers, and antioxidants, and polymer components such as acrylic resins, polyester resins, and epoxy resins. The ratio of other components is 10 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of the resist polymer. In addition, the resist agent may contain residues such as unpolymerized polysilane and vinyl polymer when the first polymer and the second polymer are polymerized.

The resist agent of this embodiment can be coated on the surface of a wafer by a method such as spin coating to form a resist film. The formed resist film can be patterned by removing street portions by irradiating with a UV laser. The patterned resist film can be used as a mask to irradiate with plasma and etch the wafer, thereby dicing the wafer. The thickness of the resist film formed on the surface of the wafer is not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 25 μm or more from the viewpoint of resist properties, and is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 35 μm or less from the viewpoint of laser processability.

The wavelength of the UV laser light used to pattern the resist agent of this embodiment is not particularly limited, but can be about 200 nm to 400 nm, with a wavelength of 355 nm being preferred. The frequency of the laser light is also not particularly limited, but can be, for example, about 1 kHz to 300 kHz, with a higher frequency being preferred from the standpoint of high-speed processing.

The resist agent of this embodiment can be processed at high speed even if the resist film is thick. Therefore, it is particularly excellent as a resist agent for forming a resist film for plasma dicing of wafers. In addition, it can be used as a resist agent capable of laser patterning, not limited to plasma dicing of wafers, and as a protective film for processes that require heat resistance.

The resin composition of the present disclosure will be described in more detail below using examples. The following examples are illustrative and are not intended to limit the present invention.

<Formation of Resist Film>
The prepared resist agent was applied to the surface of a silicon wafer (φ8 inch, thickness 700 μm) using a spin coater, and the solvent was dried to form a resist film. The rotation speed of the spin coater was set to 200 rpm, and the thickness of the resist film was set to 30 μm.

<Evaluation of liquid stability over time>
The prepared resin solution was placed in a transparent, sealed container and allowed to stand at room temperature for 7 days, after which the appearance of the resin solution and the presence or absence of precipitate were visually observed and the liquid stability over time was evaluated according to the following evaluation criteria.

(Evaluation Criteria)
A: The solution is neither cloudy nor has any precipitate.

B: There is slight cloudiness, but no sediment.

C: Separation or sediment is present.

<Evaluation of heat resistance>
5 g of the produced resin solution was placed in an aluminum cup and dried in an oven at 100°C for 180 minutes to evaporate the solvent. The non-volatile components remaining in the aluminum cup were measured for 10% weight loss temperature using a thermogravimetric differential thermal analyzer (TG-DTA). The measurement conditions were a temperature rise rate of 20°C/min and heating from 30°C to 600°C in a nitrogen atmosphere. The measurement results were evaluated for heat resistance according to the following evaluation criteria.

(Evaluation Criteria)
A: 10% weight loss temperature is 250°C or higher.

B: 10% weight loss temperature is 200°C or higher but less than 250°C.

C: 10% weight loss temperature is less than 200°C.

<Evaluation of coating surface quality>
The surface condition of the formed resist film was visually observed and the coating surface quality was evaluated according to the following evaluation criteria.

(Evaluation Criteria)
A: The coating film is uniform and free of irregularities.

B: Minor unevenness (citrus peel) is visible.

C: The coating has defects such as cracks and graininess.

<Evaluation of Laser Processability>
The surface of the formed resist film was patterned using a UV laser processing device (AL300P, manufactured by Tokyo Seimitsu) to form a checkerboard pattern with a line width of 15 μm, a line length of 15 mm, and a pitch of 1 mm. The processing conditions were a laser wavelength of 355 nm, a pulse width of <15 ns, and a frequency of 50 kHz. The processing speed was 600 mm/sec or 800 mm/sec. The laser-processed portion was observed at a magnification of 200 times using a microscope, and the laser processability was evaluated according to the following evaluation criteria.

(Evaluation Criteria)
A: There is no peeling of the coating film at the laser processed end, and no resist residue.

B: A small amount of resist residue remains on the laser processed edge.

C: Part of the resist film remains in the laser irradiated area, or defects such as peeling of the coating or cracks are found on the laser processed edge.

<Evaluation of resist properties>
After evaluating the laser processability, a plasma etching process was performed from the resist film side using a plasma etching device. The processing conditions at this time were: plasma source: ICP plasma power 2200 W, process gas: SF6 gas, gas pressure: 2 Pa, processing time: 7 minutes. The surface of the resist film after the plasma etching process was observed at 200 times magnification with a microscope, and the resist properties were evaluated according to the following evaluation criteria.

(Evaluation Criteria)
A: No erosion of the resist film due to plasma etching is observed.

B: Erosion due to plasma etching is visible, but the silicon wafer is not exposed.

C: The resist film has disappeared, revealing the exposed silicon wafer.

<Measurement of UV transmittance>
The resin solution thus produced was applied to the surface of a polyethylene terephthalate (PET) film having a thickness of 50 μm by a spin coater to form a resin film. The thickness of the resin film after drying was set to 10 μm. The transmittance of ultraviolet light having a wavelength of 355 nm was measured for the PET film on which the resin film was formed using a spectrophotometer. The transmittance of the PET film before the resin film was formed was subtracted as a blank from the obtained transmittance to obtain the transmittance of the resin film.

Example 1
The ultraviolet absorbing copolymer containing polysilane and having ultraviolet absorbing properties was a copolymer of a first polysilane and a methacrylate-based ultraviolet absorbing monomer having a benzotriazole skeleton. The first polysilane had a number average molecular weight (Mn) of 900 and a weight average molecular weight (Mw) of 1100 (Oxol SI-20-10, manufactured by Osaka Gas Chemicals). The ultraviolet absorbing monomer was 3-(2H-benzotriazol-2-yl)-4-hydroxyphenethyl methacrylate, RUVA-93, manufactured by Otsuka Chemicals. 44.2 g of the first polysilane and 15.8 g of the ultraviolet absorbing monomer were dissolved in 40 g of toluene and copolymerized to obtain a solution of an ultraviolet absorbing copolymer. The copolymerization was performed by irradiating ultraviolet light for 60 minutes using a high-pressure mercury lamp (UV intensity: 170 mW/cm ² ) at a liquid temperature of 60° C. to 70° C. under a nitrogen gas flow.

The polymer separated from the solution of the ultraviolet absorbing copolymer obtained by gel permeation chromatography (GPC) was analyzed by infrared spectroscopy (IR), and a spectrum combining the spectrum of the polysilane and the spectrum of the ultraviolet absorbing monomer was obtained. In addition, a peak of the acrylic polymer chain was confirmed at a chemical shift of 0.5 ppm to 4.5 ppm by ¹ H NMR spectroscopy. From these results, it was determined that the ultraviolet absorbing copolymer obtained was a copolymer of polysilane and an ultraviolet absorbing monomer. The Mw of the ultraviolet absorbing copolymer obtained was 3,900.

The second polysilane used had a number average molecular weight (Mn) of 2100 and a weight average molecular weight (Mw) of 12700 (Oxol SI-10-10, manufactured by Osaka Gas Chemicals). 3.2 g of the second polysilane was dissolved in 23.2 g of toluene to prepare a solution of the second polysilane.

A resist agent was prepared by mixing a solution of the ultraviolet absorbing copolymer and a solution of the second polysilane. The ratio of the second polysilane to 100 parts by mass of the ultraviolet absorbing copolymer in the resist agent was 5.3 parts by mass. The combined solid content ratio of the ultraviolet absorbing copolymer and the second polysilane in the resist agent was 50% by mass. The obtained resist agent was evaluated for liquid stability over time, coating surface quality, laser processability, resist properties, heat resistance, and UV transmittance. The liquid stability over time was A, the coating surface quality of the resist film was A, the laser processability was A when the processing speed was 600 mm/s and B when it was 800 mm/s, the resist properties were A, the heat resistance was A, and the UV transmittance was 0%.

Example 2
The same procedure as in Example 1 was repeated, except that 6.7 g of the second polysilane was dissolved in 26.7 g of toluene to prepare a solution of the second polysilane.

The ratio of the second polysilane to 100 parts by mass of the ultraviolet absorbing copolymer was 11.2 parts by mass, and the ratio of solids in the resist agent was 50% by mass. The liquid stability over time was A, the coating surface quality was A, the laser processability was A at both processing speeds of 600 mm/s and 800 mm/s, the resist property was A, the heat resistance was A, and the UV transmittance was 0%.

Example 3
The same procedure as in Example 1 was repeated, except that 15.0 g of the second polysilane was dissolved in 35.0 g of toluene to prepare a solution of the second polysilane.

The ratio of the second polysilane to 100 parts by mass of the ultraviolet absorbing copolymer was 25.0 parts by mass, and the ratio of solids in the resist agent was 50% by mass. The liquid stability over time was A, the coating surface quality was A, the laser processability was A at both processing speeds of 600 mm/s and 800 mm/s, the resist property was A, the heat resistance was A, and the UV transmittance was 0%.

Example 4
The same procedure as in Example 1 was repeated, except that 25.7 g of the second polysilane was dissolved in 45.7 g of toluene to prepare a solution of the second polysilane.

The ratio of the second polysilane to 100 parts by mass of the ultraviolet absorbing copolymer was 42.8 parts by mass, and the ratio of solids in the resist agent was 50% by mass. The liquid stability over time was A, the coating surface quality was B, the laser processability was A at both processing speeds of 600 mm/s and 800 mm/s, the resist property was A, the heat resistance was A, and the UV transmittance was 0%.

Example 5
The procedure was the same as in Example 2, except that 57.0 g of the first polysilane and 3.0 g of the ultraviolet absorbing monomer were polymerized to obtain an ultraviolet absorbing copolymer.

The ratio of the second polysilane to 100 parts by mass of the ultraviolet absorbing copolymer was 11.2 parts by mass, and the ratio of solids in the resist agent was 50% by mass. The liquid stability over time was A, the coating surface quality was A, the laser processability was A when the processing speed was 600 mm/s and B when it was 800 mm/s, the resist property was A, the heat resistance was A, and the UV transmittance was 0%.

Example 6
The procedure was the same as in Example 2, except that 18.0 g of the first polysilane and 42.0 g of the ultraviolet absorbing monomer were polymerized to obtain an ultraviolet absorbing copolymer.

The ratio of the second polysilane to 100 parts by mass of the ultraviolet absorbing copolymer was 11.2 parts by mass, and the ratio of solids in the resist agent was 50% by mass. The liquid stability over time was A, the coating surface quality was A, the laser processability was A at both processing speeds of 600 mm/s and 800 mm/s, the resist property was A, the heat resistance was B, and the UV transmittance was 0%.

(Example 7)
The procedure was the same as in Example 2, except that the first polysilane had a number average molecular weight (Mn) of 1100 and a weight average molecular weight (Mw) of 1800 (Oxol SI-10-20, manufactured by Osaka Gas Chemicals).

The ratio of the second polysilane to 100 parts by mass of the ultraviolet absorbing copolymer was 11.2 parts by mass, and the ratio of solids in the resist agent was 50% by mass. The liquid stability over time was A, the coating surface quality was A, the laser processability was A at both processing speeds of 600 mm/s and 800 mm/s, the resist property was A, the heat resistance was A, and the UV transmittance was 0%.

The conditions and evaluation results for Examples 1 to 7 are shown in Table 1.

(Reference Example 1)
The ultraviolet absorbing copolymer was prepared by dissolving 52.5 g of polysilane and 22.5 g of ultraviolet absorbing monomer in 75 g of toluene and copolymerizing them, and the resist agent was prepared without adding the second polysilane. Also, the resist film was evaluated with a thickness of 10 μm.

Liquid stability over time was A, coating surface quality was A, laser processability was A at a processing speed of 600 mm/s and B at 800 mm/s, resist property was A, heat resistance was A, and UV transmittance was 0%.

(Reference Example 2)
The same procedure as in Example 1 was repeated, except that the thickness of the resist film was changed to 30 μm.

Liquid stability over time was A, coating surface quality was A, laser processability was A when the processing speed was 600 mm/s and C when it was 800 mm/s, resist property was A, heat resistance was A, and UV transmittance was 0%.

The conditions and evaluation results for Reference Examples 1 and 2 are shown in Table 2.

(Comparative Example 1)
The resist agent was prepared by dissolving 75.0 g of polyvinyl alcohol (PVA-205, manufactured by Kuraray) in 75.0 g of distilled water.

The liquid stability over time was A, the coating surface quality was A, the laser processability was C at a processing speed of 600 mm/s, the resist property was A, the heat resistance was C, and the UV transmittance was 90%. Note that the processability at a processing speed of 800 mm/s was not evaluated.

(Comparative Example 2)
The resist agent was prepared by dissolving 75.0 g of polysilane (Oxol SI-20-10, manufactured by Osaka Gas Chemicals) in 75.0 g of toluene.

The liquid stability over time was A, the coating surface quality was A, the laser processability was C at a processing speed of 600 mm/s, the resist property was B, the heat resistance was A, and the UV transmittance was 63%. Note that the processability at a processing speed of 800 mm/s was not evaluated.

(Comparative Example 3)
The procedure was the same as in Example 1, except that the resist agent was a solution of 52.5 g of polysilane (Oxol SI-20-10, manufactured by Osaka Gas Chemicals) and 22.5 g of a benzotriazole-based ultraviolet absorber (2-(2-hydroxy-5-t-butylphenyl)benzotriazole, Tinuvin PS, manufactured by BASF Japan) dissolved in 75.0 g of toluene. The liquid stability over time was C, the coating surface quality was C, and other items could not be evaluated.

The conditions and evaluation results for Comparative Examples 1 to 3 are shown in Table 3.

(Comparative Example 4)
The same procedure was followed as in Example 1, except that a solution in which 3.2 g of an acrylic resin (Dianal BR-113, manufactured by Mitsubishi Chemical) having a number average molecular weight of 30,000 was dissolved in 23.2 g of toluene was used instead of the solution of the second polysilane. The liquid stability over time was B, the coating surface quality was C, and other items could not be evaluated.

(Comparative Example 5)
The same procedure was followed as in Comparative Example 4, except that 57.0 g of the first polysilane and 3.0 g of the ultraviolet absorbing monomer were dissolved in 40 g of toluene and copolymerized to prepare a solution of an ultraviolet absorbing copolymer. The liquid stability over time was B, the coating surface quality was C, and other items could not be evaluated.

(Comparative Example 6)
The same procedure was followed as in Comparative Example 4, except that 18.0 g of the first polysilane and 42.0 g of the ultraviolet absorbing monomer were dissolved in 40 g of toluene and copolymerized to prepare a solution of an ultraviolet absorbing copolymer. The liquid stability over time was B, the coating surface quality was C, and other items could not be evaluated.

(Comparative Example 7)
The procedure was the same as in Example 1, except that a solution containing 3.2 g of polyester resin (Vylon UR-1400, manufactured by Toyobo Co., Ltd.) having a number average molecular weight of 40,000 and toluene was added to the solution to adjust the amount of solvent to 23.2 g was used instead of the solution of the second polysilane. The liquid stability over time was rated C, the coating surface quality was rated C, and other items could not be evaluated.

The conditions and evaluation results for Comparative Examples 4 to 7 are shown in Table 4.

The resin composition disclosed herein has excellent laser processability and is useful as an ultraviolet laser processing resist, etc.

Claims (7)

an ultraviolet absorbing copolymer having a first block made of a first polysilane and a second block which is a copolymer of a vinyl monomer and contains an ultraviolet absorbing monomer unit derived from an ultraviolet absorbing monomer having an ultraviolet absorbing effect;
A second polysilane having a molecular weight greater than that of the first polysilane ,
The resin composition for a resist for ultraviolet laser processing , wherein the ultraviolet absorbing monomer has any one of a benzotriazole skeleton, a benzophenone skeleton, and a triazine skeleton . 2. The resin composition for use as a resist for ultraviolet laser processing according to claim 1, which has an ultraviolet transmittance of 2% or less at a wavelength of 355 nm. an ultraviolet absorbing copolymer having a first block made of a first polysilane and a second block which is a copolymer of a vinyl monomer and contains an ultraviolet absorbing monomer unit derived from an ultraviolet absorbing monomer having an ultraviolet absorbing effect;
A second polysilane having a molecular weight greater than that of the first polysilane,
A resin composition for use as a resist for ultraviolet laser processing, having an ultraviolet transmittance of 2% or less at a wavelength of 355 nm. 4. The resin composition for an ultraviolet laser processing resist according to claim 3, wherein the ultraviolet absorbing monomer has any one of a benzotriazole skeleton, a benzophenone skeleton, and a triazine skeleton. The weight average molecular weight of the second polysilane is 10,000 or more and 50,000 or less,
The resin composition for ultraviolet laser processing resist according to any one of claims 1 to 4, wherein the proportion of the second polysilane is 5 parts by mass or more and less than 45 parts by mass with respect to 100 parts by mass of the ultraviolet absorbing copolymer. a ratio of the ultraviolet absorbing monomer unit to the entire ultraviolet absorbing copolymer is 3 mass% or more and 70 mass% or less,
The resin composition for ultraviolet laser processing resist according to any one of claims 1 to 5 , wherein the proportion of the first polysilane in the entire ultraviolet absorbing copolymer is 30 mass% or more and 97 mass% or less. A resist agent comprising the resin composition according to any one of claims 1 to 6 and a solvent.