Method for producing modified polysilazane cured coating film, and modified polysilazane cured coating film

Abstract

Provided are: a method for producing a modified polysilazane cured coating film, with which it is possible to densify a film comprising a polysilazane compound in a short period of time; and a modified polysilazane cured coating film obtained by means of the method for producing the modified polysilazane cured coating film. A film having a sufficiently low water vapor transmission rate is produced in a short period of time. When curing the polysilazane compound, a coating material containing the polysilazane compound is irradiated with vacuum ultraviolet light (VUV) at an irradiation intensity within a specific range. Specifically, the method comprises: a coating step for coating a substrate with a solution containing a polysilazane compound represented by general formula (1) to form a coated article; and a curing step in which the coating material is irradiated with Xe excimer light to modify the polysilazane compound to form a cured film of the modified polysilazane compound, the illumination of the Xe excimer light in the curing step being in the range of 280-450 mW / cm2. General formula 1

Description

Technical Field

[0001] This invention relates to a method for manufacturing a modified polysilazane-cured coating and the modified polysilazane-cured coating. Background Technology

[0002] Gas barrier membranes are widely used in various packaging and electronic devices. Especially in electronic products, high water vapor barrier performance is required. The indicator of water vapor barrier performance is water vapor transmission rate (WVTR). For example, in semiconductor devices such as organic EL elements and solar cells, a water vapor transmission rate of 10 is required. -3 ~10 -6 g / m 2 / day of barrier performance.

[0003] Inorganic barrier membranes fabricated using vacuum processes such as atomic layer deposition (ALD) and chemical vapor deposition (CVD) achieve very low water vapor permeability. To mitigate the stress of such inorganic barrier membranes, a barrier structure with an inorganic / organic alternating laminate structure incorporating polymers as stress-relieving layers and an inorganic barrier membrane and stress-relieving layer has been proposed.

[0004] However, vacuum processes suffer from problems such as foreign matter adhesion due to low material utilization efficiency and repeated processes involving atmospheric / vacuum pressure differences. Furthermore, the film formation rate is slower than wet processes. Moreover, in alternating layered structures, the polymer serving as the stress-relieving layer is typically fabricated using coating methods, necessitating alternating vacuum and coating processes, which increases manufacturing costs.

[0005] On the other hand, a gas barrier layer consisting of both a stress-relieving layer and an inorganic barrier film was also reported using a coating process. This gas barrier structure, entirely fabricated using solution processing, achieves high resource efficiency and high throughput while minimizing manufacturing costs.

[0006] However, the water vapor permeability of membranes obtained by all-solution processes such as the general sol-gel method is 3–350 g / m³. 2 It takes about 1 day to achieve its density and barrier properties, which are lower than those of vacuum processes.

[0007] In the formation of barrier films based on vacuum processes, there are issues such as low film formation rate and low throughput. Therefore, a film formation method that combines vacuum and wet processes using all-hydrogen polysilazane (PHPS) is being investigated.

[0008] Perhydropolysilazane (PHPS) is a reactive polymer with Si-N bonds as its main backbone, capable of film formation using wet processes such as coating. When heated in the atmosphere, it reacts with oxygen to form a SiO2 film. However, it can also be converted into a SiO2 film under atmospheric vacuum ultraviolet (VUV) light without heating. The barrier properties of the SiO2 film obtained from PHPS are 10. -1 ~10 -2 g / m 2 / day, depending on the production conditions, it can reduce the water vapor permeability to 10%. -3 g / m 2 Approximately one day.

[0009] However, the barrier properties of SiO2 films are insufficient for applications in water vapor-sensitive electronic products. Therefore, a method was proposed to irradiate all-hydrogen polysilazane (PHPS) films with vacuum ultraviolet (VUV) light under a nitrogen atmosphere, transforming them into silicon nitride (SiN). x A scheme for a silicon nitride (SiN) membrane (Patent Document 1). x The membrane of this system has high water vapor barrier properties.

[0010] Non-Patent Document 1 describes a gas barrier layer fabricated using a solution-based process, employing polydimethylsiloxane (PDMS) with Si-O bonds as the main framework in the stress-relieving layer and perhydropolysilazane (PHPS) in the barrier layer. Furthermore, the perhydropolysilazane (PHPS) film is irradiated with vacuum ultraviolet light (VUV) under a nitrogen atmosphere, thereby transforming it into silicon nitride (SiN). x The resulting silicon nitride (SiN) film was obtained. x The water vapor permeability of the membrane reaches 10. -3 g / m 2 / sky.

[0011] Existing technical documents

[0012] Patent documents

[0013] Patent Document 1: Japanese Patent Application Publication No. 2024-43265

[0014] Non-patent literature

[0015] Non-patent literature 1: ACS Appl. Mater. Interfaces 11(46), 43425-43432(2019) Summary of the Invention

[0016] The low water vapor transmission rate of perhydropolysilazane (PHPS) cured films is achieved through densification using vacuum ultraviolet (VUV) irradiation. When PHPS films are irradiated with VUV light, not only are the Si-H or NH bonds broken, but the Si-N bonds in the main chain are also repeatedly broken and recombined, resulting in atomic rearrangement. Furthermore, this atomic rearrangement reduces the porosity of the film, thereby achieving densification.

[0017] Previously, to impart high density to polysilazane-cured films, sufficient vacuum ultraviolet (VUV) irradiation was required, which could take several minutes or more. Therefore, from the perspective of film productivity, there is a desire to accelerate the densification process.

[0018] The present invention was made in view of the above circumstances, and its object is to provide a method for manufacturing a modified polysilazane cured film and a modified polysilazane cured film obtained by the manufacturing method, the method for manufacturing a modified polysilazane cured film being able to densify a film composed of a polysilazane compound in a short time and to manufacture a film with sufficiently low water vapor permeability in a short time.

[0019] To achieve the above objectives, the inventors conducted repeated and in-depth research. They discovered that by irradiating a coating containing a polysilazane compound with vacuum ultraviolet (VUV) light at a specific range of intensity, a modified polysilazane cured film with the same gas barrier properties as before can be formed with a smaller cumulative light intensity than previously required. As a result, a modified polysilazane cured film with the same gas barrier properties as before was obtained in a short time, thus completing this invention.

[0020] That is, the present invention includes the following methods.

[0021] [1] A method for manufacturing a modified polysilazane-cured film, comprising:

[0022] The coating process involves coating a solution comprising a polysilazane compound represented by the following general formula (1) onto a substrate to form a coating; and the curing process involves irradiating the coating with Xe excimer light to modify the polysilazane compound, thereby forming a cured film of the modified polysilazane compound, wherein...

[0023] The illuminance of the Xe excimer light during the curing process is 280–450 mW / cm². 2 .

[0024]

General Formula 1

[0025]

[0026] (In general formula (1), x is an integer of 20 < x ≤ 1000, and y is an integer of 0 ≤ y < (x / 10).)

[0027] [2] The method for manufacturing the modified polysilazane cured film according to method [1], wherein,

[0028] The modified polysilazane compound has a total nitrogen and oxygen atom count relative to the silicon atom count (N+O) / Si ratio of 0.9 to 1.1.

[0029] [3] The method for manufacturing the modified polysilazane cured film according to method [1], wherein,

[0030] The polysilazane compound is a perhydropolysilazane.

[0031] [4] The method for manufacturing the modified polysilazane cured film according to method [1], wherein,

[0032] The cumulative light intensity of the Xe excimer light irradiating the coating is 1000–10000 mJ / cm. 2 .

[0033] [5] The method for manufacturing the modified polysilazane cured film according to method [1], wherein,

[0034] The Xe excimer light was irradiated in a nitrogen atmosphere with an oxygen concentration of less than 0.1%.

[0035] [6] The method for manufacturing the modified polysilazane cured film according to method [1], wherein,

[0036] The substrate is an organic resin film.

[0037] [7] The method for manufacturing the modified polysilazane cured film according to method [1], wherein,

[0038] The substrate is a polyimide (PI) film or a polyethylene terephthalate (PET) film.

[0039] [8] A modified polysilazane-cured coating,

[0040] The modified polysilazane cured film is obtained by the manufacturing method of any one of the methods [1] to [7].

[0041] According to the present invention, it is possible to manufacture a modified polysilazane cured film with the same gas barrier properties as before in a short time.

[0042] Furthermore, the method for manufacturing the modified polysilazane cured film of the present invention can produce a modified polysilazane cured film with a higher level of gas barrier properties than before, using less cumulative light intensity than previously required. Therefore, it is possible to manufacture a polysilazane cured film with gas barrier properties with high efficiency using less energy than before.

[0043] Furthermore, the method for manufacturing the modified polysilazane cured film of the present invention can produce a modified polysilazane cured film with higher gas barrier properties than before, with the same cumulative light intensity as before.

[0044] Therefore, the method for manufacturing the modified polysilazane cured film according to the present invention can obtain a silicon coating material with high resource efficiency, high throughput and high gas barrier properties in a short time through a coating process. Attached Figure Description

[0045] Figure 1 This is a graph showing the results of elemental analysis performed on the polysilazane used in the examples and comparative examples using the RBS / HFS method.

[0046] Figure 2 This shows that in Comparative Example 1, the cumulative light intensity was 6 J / cm². 2 The figure shows the results of elemental analysis of the modified all-hydrogen polysilazane cured film obtained below.

[0047] Figure 3 This shows that in Example 2, the cumulative light intensity was 6 J / cm². 2 The figure shows the results of elemental analysis of the modified all-hydrogen polysilazane cured film obtained below.

[0048] Figure 4 The results of the refractive index distribution of the modified polysilazane cured films of Comparative Examples 1 to 3 based on a spectroscopic ellipsometry are shown.

[0049] Figure 5 The results of refractive index distribution of the modified polysilazane cured films of Examples 1-3 are shown based on a spectroscopic ellipsometry.

[0050] Figure 6 This is a graph showing the relationship between the refractive index of the TOP layer of the modified polysilazane cured film and the lamp intensity (irradiation intensity). Detailed Implementation

[0051] <<Manufacturing Method of Modified Polysilazane Cured Film>>

[0052] The method for manufacturing the modified polysilazane cured film of the present invention includes: a coating step, wherein a solution containing a polysilazane compound is coated onto a substrate to form a coating; and a curing step, wherein the coating is irradiated with Xe excimer light to modify the polysilazane compound, thereby forming a cured film of the modified polysilazane compound, wherein the irradiance of the Xe excimer light in the curing step is set within a specific range. Furthermore, if necessary, a drying step may be included between the coating step and the curing step, wherein the drying step evaporates the solvent contained in the coating formed in the coating step by heating or the like, thereby forming a dried coating. The elements are described below.

[0053] <Polysilazane compounds>

[0054] The polysilazane compound used in the method for manufacturing the modified polysilazane cured film of the present invention is represented by the following general formula (1). There are no particular limitations as long as it is represented by the following general formula (1), and any compound can be selected as long as it does not impair the effects of the present invention.

[0055]

General Formula 1

[0056]

[0057] (In general formula (1), x is an integer of 20 < x ≤ 1000, and y is an integer of 0 ≤ y < (x / 10).)

[0058] The polysilazane compound used in the manufacturing method of the modified polysilazane cured film of the present invention can be used alone or two or more at the same time.

[0059] From the viewpoint of solubility and reactivity in solvents, the mass-average molecular weight of the polysilazane compound used in this invention is, for example, 900 to 50,000, more preferably 900 to 20,000. Furthermore, the mass-average molecular weight mentioned here is the mass-average molecular weight converted from polystyrene, which can be determined by gel permeation chromatography.

[0060] In general formula (1), x is preferably an integer of 30 < x ≤ 600, more preferably an integer of 60 < x ≤ 400, and particularly preferably an integer of 100 < x ≤ 200.

[0061] In the method for manufacturing the modified polysilazane cured film of the present invention, the ratio of the total number of nitrogen atoms and oxygen atoms of the polysilazane compound used to the number of silicon atoms (N+O) / Si is preferably 0.9 to 1.1. Within this range, a cured film with sufficiently low water vapor transmission rate (WVTR) can be formed.

[0062] The ratio of the total number of nitrogen atoms and oxygen atoms to the number of silicon atoms in the modified polysilazane compound (N+O) / Si is more preferably 0.90 to 1.05, and particularly preferably 0.90 to 1.00.

[0063] The polysilazane compound used in the manufacturing method of the modified polysilazane cured film of the present invention is preferably a perhydropolysilazane (PHPS) or a modified thereof in which y = 0 in the above general formula (1). Perhydropolysilazane (PHPS) is a silicon-containing polymer containing Si-N bonds as repeating units and composed only of Si, N, and H. In addition to Si-N bonds, all elements bonded to Si and N in perhydropolysilazane (PHPS) are H, and it essentially does not contain carbon or oxygen.

[0064] Furthermore, in the above general formula (1), polysilazane compounds other than y=0 can be manufactured, for example, in the following manner: Relative to the total mass of the chlorosilane and the organic solvent, in the presence of a specific amount of water, the chlorosilane and the organic solvent are mixed under a nitrogen atmosphere. Then, after introducing ammonia, the generated salt is removed, thereby obtaining a solution containing the polysilazane compound. Furthermore, by adjusting the amount of water in the reaction, a polysilazane compound with the desired composition represented by general formula (1) can be manufactured. Specifically, it can be obtained, for example, by the following method.

[0065] (Examples of manufacturing polysilazane compounds other than y=0)

[0066] 0.19 mol of dichlorosilane with a purity of ≥99% was stirred together with nitrogen while 300 ml of pyridine at -10°C containing 373 ppm of water was introduced. At this point (initial reaction), the water content (initial water content) relative to the total mass of the chlorosilane and amine was 350 ppm.

[0067] Next, 0.57 mol of ammonia with a purity of over 99% was introduced, and the generated salt was removed by pressure filtration, yielding a solution containing dissolved polysilazane compounds. At this point (at the end of the reaction), the overall water content of the solution (final water content) was 412 ppm.

[0068] The resulting solution containing the polysilazane compound was heated to 150°C, and 150 ml of pyridine was removed by distillation. Then, 300 ml of dibutyl ether was added, and pyridine was removed by azeotropic distillation, thereby obtaining the polysilazane compound.

[0069] In the general formula (1) of the obtained polysilazane compound, x is 170 and y is 10.

[0070] <Modified polysilazane cured film>

[0071] The modified polysilazane-cured coating obtained by the manufacturing method of the modified polysilazane-cured coating of the present invention is a coating formed on a substrate by curing the above-mentioned polysilazane compound.

[0072] The modified polysilazane cured film obtained by the manufacturing method of the present invention has a refractive index distribution in the thickness direction. Without significant compositional changes, the refractive index is related to density, and thus becomes an indicator of compactness. That is, the region near the surface irradiated with Xe excimer light has a higher refractive index because the densification of polysilazane is easier, while the region near the substrate has a lower refractive index because Xe excimer light has difficulty reaching it.

[0073] Specifically, the refractive index of the region near the surface irradiated with Xe excimer light is 1.6 to 2.0, preferably 1.65 to 1.85, and the refractive index of the region near the substrate is 1.50 to 1.6, preferably 1.50 to 1.54.

[0074] Furthermore, the refractive index distribution along the thickness direction of the modified polysilazane cured film can be determined using a spectroscopic ellipsometry. The refractive index distribution can be, for example, a four-layer analytical model incorporating a thin SiO2 layer formed on the surface of the modified polysilazane cured film.

[0075] <Coating Process>

[0076] The coating step in the manufacturing method of the modified polysilazane cured film of the present invention is a step of coating a solution containing a polysilazane compound onto a substrate to form a coating.

[0077] [solvent]

[0078] There are no particular limitations on the solvents used to dissolve polysilazane compounds. Examples include aromatic compounds such as benzene, toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene, and triethylbenzene; chain hydrocarbons such as pentane, 2-methylbutane, hexane, 2-methylpentane, heptane, 2-methylhexane, octane, 2,2,4-trimethylpentane, nonane, decane, and 2-methylnonane; cyclic hydrocarbons such as ethylcyclohexane, methylcyclohexane, cyclohexane, p-menthane, decahydronaphthalene, and dipentene; ethers such as dipropyl ether, dibutyl ether (DBE), and methyl tert-butyl ether (MTBE); and ketones such as methyl isobutyl ketone (MIBK). Furthermore, one or more of these solvents can be used alone or in combination.

[0079] [concentration]

[0080] The concentration of the polysilazane compound in the solution varies depending on the coating method, and is typically 5 to 95% by weight, preferably 5 to 20% by weight.

[0081] [Other ingredients]

[0082] Within the scope of not impairing the effects of the present invention, other components besides the polysilazane compound may be incorporated into the solution containing the polysilazane compound. Examples of such other components include fillers, leveling agents, antistatic agents, additives such as ultraviolet absorbers, and surfactants. When a filler is incorporated, the amount is typically 0.05 to 10 parts by weight, preferably 0.2 to 3 parts by weight, relative to 1 part by weight of the polysilazane compound.

[0083] [Substrate]

[0084] The substrate used in the manufacturing method of the modified polysilazane-cured film of the present invention is not particularly limited and can be an organic resin film. Since organic resin films generally have high moisture permeability, the modified polysilazane-cured film obtained in this invention can impart high gas barrier properties.

[0085] The substrate used in the manufacturing method of the modified polysilazane cured film of the present invention is more preferably a polyimide (PI) film or a polyethylene terephthalate (PET) film.

[0086] Furthermore, the substrate used in the manufacturing method of the modified polysilazane cured film of the present invention can be a thin film glass with a thickness of about 10 to 150 μm, depending on the application. The thin film glass can be a monomer, or it can be a thin film glass on which metal foils such as aluminum foil and resin are laminated or pressed. Furthermore, the substrate used in the manufacturing method of the modified polysilazane cured film of the present invention can be a metal foil such as stainless steel foil, aluminum foil, or copper foil.

[0087] Alternatively, the surface of the substrate can be degreased or cleaned before applying a solution containing a polysilazane compound, thereby facilitating the adhesion of the light- or heat-cured resin to the substrate. Examples of methods for degreasing or cleaning the substrate surface include excimer laser treatment, UV ozone treatment, atmospheric pressure plasma treatment, plasma treatment, and corona discharge treatment.

[0088] [Coating Method]

[0089] There are no particular limitations on the method for coating a solution containing a polysilazane compound onto a substrate, and known methods can be used. Examples of methods for coating a solution containing a polysilazane compound onto a substrate include spin coating, roller coating, flow coating, inkjet coating, spray coating, dip coating, casting film formation, rod coating, die coating, gravure coating, gravure printing, and screen printing.

[0090] Alternatively, the surface of the substrate can be degreased or cleaned before applying the solution containing the polysilazane compound to the substrate, thereby making it easier for the polysilazane compound to adhere to the substrate.

[0091] The coating of the substrate can be carried out at room temperature in an inert atmosphere such as nitrogen, or it can be carried out under the atmosphere. Compared with carrying out the coating under an inert gas atmosphere that requires a closed system, carrying it at room temperature or under the atmosphere is less labor-intensive and less costly.

[0092] Furthermore, substrates coated with solutions containing polysilazane compounds can be surface-modified using ozone cleaning with vacuum ultraviolet light or ultraviolet light. Active oxygen separated from the ozone generated by vacuum ultraviolet light or ultraviolet light collides with the substrate surface, decomposing and removing organic pollutants present on the substrate surface. Substrates surface-modified by ozone cleaning exhibit improved wettability, making it easier to coat solutions containing polysilazane compounds onto the substrate.

[0093] <Drying Process>

[0094] If the coating obtained in the coating process contains a large amount of solvent, a drying process can be performed before the curing process described later. The drying process in the method for manufacturing the modified polysilazane cured film of the present invention is as follows: the coating obtained in the coating process is heated by heating with a heater or irradiated with energy rays such as infrared rays to evaporate the solvent remaining in the coating, thereby obtaining a dried coating.

[0095] There are no particular restrictions on the conditions for heating the coating, as long as the residual solvent evaporates sufficiently at the required temperature and time. However, if heating is performed above the boiling point of the solvent or the heat resistance temperature of the substrate, voids may be created in the coating, or the substrate may shrink or deform. Therefore, the heating temperature must be considered to avoid such situations.

[0096] <Curing Process>

[0097] The curing step in the manufacturing method of the modified polysilazane cured film of the present invention is as follows: irradiating the coating obtained in the coating step with Xe excimer light to modify the polysilazane compound and form a cured film of the modified polysilazane compound.

[0098] [Xe excimer light]

[0099] The Xe excimer light used to irradiate the coated material obtained in the coating process is vacuum ultraviolet (VUV) light with a wavelength of 172 nm. Vacuum ultraviolet (VUV) irradiation is usually performed using commercially available excimer lamps (wavelength 172 nm).

[0100] [Illuminance]

[0101] In the method for manufacturing the modified polysilazane cured film of the present invention, the illuminance of Xe excimer light irradiating the coating obtained in the coating process is 280 to 450 mW / cm². 2 Within this range. In this invention, by using Xe excimer light with illuminance within this range, it is possible to densify a film composed of polysilazane compounds in a short time, and to produce a modified polysilazane cured film with sufficiently low water vapor transmittance in a short time.

[0102] [Cumulative Light Quantity]

[0103] The cumulative light intensity of Xe excimer light irradiating the coated material obtained in the coating process is preferably 1000–10000 mJ / cm. 2 The range. Cumulative light intensity (mJ / cm²) 2 Illuminance of Xe excimer light (mW / cm²) 2 Calculate by multiplying the curing time (sec).

[0104] The cumulative light intensity can also exceed 10,000 mJ / cm². 2 The cumulative light intensity is high, but in this case, the effect obtained by the present invention becomes weak.

[0105] The method for manufacturing the modified polysilazane cured film of the present invention not only enables the production of a modified polysilazane cured film with sufficiently low water vapor transmission in a short time, but also enables the manufacture of a modified polysilazane cured film with a higher level of gas barrier properties than before, using less cumulative light intensity than previously required. Therefore, it is possible to manufacture a polysilazane cured film with gas barrier properties with high efficiency and less energy than before.

[0106] Furthermore, the method for manufacturing the modified polysilazane cured film of the present invention can produce a modified polysilazane cured film with higher gas barrier properties than before, with the same cumulative light intensity as before.

[0107] [atmosphere]

[0108] There are no particular limitations on the atmosphere for carrying out the curing process. However, if the coating containing the polysilazane compound is irradiated with vacuum ultraviolet light (VUV), the Si-N bonds in the main chain are repeatedly broken and recombined, causing atomic rearrangement. Through this atomic rearrangement, the porosity of the film is reduced, and the film is densified. Therefore, for the purpose of facilitating film densification, the atmosphere for irradiating with Xe excimer light is preferably a nitrogen atmosphere.

[0109] Furthermore, in the method for manufacturing the modified polysilazane cured film of the present invention, Xe excimer light is preferably used for irradiation in a nitrogen atmosphere with an oxygen concentration of 0.1% or less. By irradiating the film with Xe excimer light in a nitrogen atmosphere that is almost oxygen-free, the film can be further densified, and a modified polysilazane cured film with a high level of gas barrier properties can be manufactured in a short time.

[0110] There is no particular limitation on the temperature for carrying out the curing process; for example, it can be carried out at room temperature (approximately 15–40°C). For example, it can also be carried out under heating conditions such as 100–120°C, but the same effect can be obtained even if it is carried out at room temperature.

[0111] <<Applications of Modified Polysilazane Cured Films>>

[0112] The modified polysilazane cured film obtained in this invention has excellent gas barrier properties, and therefore can be used as a gas barrier layer in various applications.

[0113] In addition to its gas barrier properties, the cured film obtained from polysilazane also exhibits excellent heat resistance and insulation. Therefore, for example, by forming a modified polysilazane cured film on the surface of a resin film, it can be used as a sealing material for organic EL elements.

[0114]

Example

[0115] The present invention will now be described in more detail based on embodiments, but the present invention is not limited to the following embodiments.

[0116] <Examples 1-3, Comparative Examples 1-3>

[0117] A solution containing perhydropolysilazane (PHPS) was coated onto a silicon wafer (Si), and the resulting coating was irradiated with Xe excimer light (VUV light) at six different lamp intensities to produce a modified polysilazane cured film.

[0118] in addition, Figure 1 The results of elemental analysis of the perhydropolysilazane (PHPS) used are shown. Figure 1 The graph shown is an analysis of the elemental ratios of the polymer using Rutherford backscattering spectroscopy (RBS) and hydrogen backscattering analysis (HFS). Additionally, the analysis graph is the uncorrected version showing the number of hydrogen atoms removed.

[0119] In addition, Table 1 shows the elemental analysis results after correcting for the calibration lines made by the detached hydrogen atoms.

[0120] Table 1

[0121]

[0122] The elemental ratios relative to the number of silicon atoms were calculated based on the obtained elemental analysis results and are shown in Table 2.

[0123] Table 2

[0124]

[0125] [Coating Process]

[0126] A 20% dibutyl ether (DBE) solution of perhydropolysilazane (PHPS) was diluted with anhydrous DBE solution under nitrogen to prepare a 10% PHPS DBE solution. The prepared 10% PHPS DBE solution was spin-coated onto a 30×30 mm silicon wafer (Si) in atmospheric conditions (25°C, 25% humidity) to fabricate a PHPS-coated film / Si. Spin-coating was performed at 2000 rpm for 30 seconds.

[0127] [Curing Process]

[0128] The obtained PHPS-coated film / Si was irradiated with Xe excimer light (VUV light) to prepare a modified polysilazane-cured film. The Xe excimer light (VUV light) irradiation was performed using an excimer irradiation device (wavelength = 172 nm) manufactured by MDCOM.

[0129] (Illumination atmosphere)

[0130] Xe excimer light (VUV light) irradiation was carried out under a nitrogen atmosphere (oxygen and water vapor concentration <0.01%).

[0131] (Irradiation intensity)

[0132] Lamp intensity (irradiance) is 103–328 mW / cm² 2 The six values ​​between (103, 229, 259, 290, 309, 328 mW / cm) 2 The distance between the lamp and the PHPS coated film / Si was set to 2 mm. Here, the lamp intensity (irradiation intensity) represents the actual irradiation intensity on the PHPS coated film. Specifically, using a power meter manufactured by Hamamatsu Photonics (C9536, sensor head: H9535-172), the irradiation intensity of Xe excimer light (VUV light) was measured with the sensor head distance from the lamp set to 2 mm, the same as the distance between the lamp and the PHPS coated film.

[0133] The lamp intensity (irradiation intensity) is 103 mW / cm². 2 As a comparative example 1, 229mW / cm 2 As a comparative example 2, 259mW / cm 2 As a comparative example 3, 290mW / cm 2As an example 1, 309mW / cm 2 As an example 2, 328mW / cm 2 As an example 3.

[0134] (Cumulative light volume)

[0135] The cumulative light intensity of Xe excimer light (VUV light) is 6–72 J / cm². 2 .

[0136] in addition, Figure 2 The lamp intensity (irradiation intensity) is shown to be 103 mW / cm. 2 In Comparative Example 1, for a cumulative light intensity of 6 J / cm 2 The results of elemental analysis were obtained for the modified all-hydrogen polysilazane cured film. Furthermore, Figure 3 The lamp intensity (irradiance) is shown to be 309 mW / cm². 2 In Example 2, the cumulative light intensity was 6 J / cm². 2 The results of elemental analysis were obtained from the modified all-hydrogen polysilazane cured film.

[0137] In both Comparative Example 1 and Example 2, although the surface (0 nm) of the cured film was oxidized, the interior of the cured film was composed of a high nitrogen content. Furthermore, the internal composition remained almost unchanged in Comparative Example 1 and Example 2, with Si approximately 56%, N approximately 38%, and O approximately 6%.

[0138] (Determination of refractive index distribution)

[0139] The density of the modified polysilazane cured film was measured using a spectroellipsometer (manufactured by JAWoolam Japan Co., Ltd., model: WoollamVASE32) as the refractive index distribution along the film thickness direction. In the absence of significant compositional changes, since the refractive index is related to density, it serves as an indicator of density (compactness).

[0140] The ellipsometry was used to measure wavelengths from 250 to 1000 nm, with the incident angle varying at seven different angles: 45°, 50°, 55°, 60°, 65°, 70°, and 75°. The results were then used to fit the four-layer modified polysilazane cured film / Si structure.

[0141] The refractive index distribution in the thickness direction of photodensitized modified polysilazane-cured films is also known from previous research (Adv. Mater. Interfaces, 2201517(8pp.)(2022)). Therefore, the outermost layer, a SiO2 layer formed by the natural oxidation of all-hydrogen polysilazane (PHPS), will be fitted as a three-layer structure (Top, Mid, and Bot) in the thickness direction for the SiN layer region between the SiO2 and Si layers. In particular, to quantitatively evaluate the Top layer, which is most strongly affected by Xe excimer light (VUV light) irradiation and is prone to photodensitization, the thickness of the Top layer is fixed at 30 nm.

[0142] Figure 4 as well as Figure 5 The results are shown. In addition, Table 3 and... Figure 6 The cumulative luminous flux at each lamp intensity (irradiation intensity) is shown to be 6 J / cm². 2 12J / cm 2 24J / cm 2 72J / cm 2 The refractive index of the TOP layer (30 nm) at that time is given in Table 4, and the irradiation time required to reach each cumulative light intensity is shown in Table 4.

[0143] Table 3

[0144]

[0145] Table 4

[0146]

[0147] [Inspection]

[0148] Among all lamp intensities (irradiation intensities), the refractive index of the TOP layer increases due to the increase in cumulative light intensity.

[0149] Furthermore, under the same cumulative light intensity, the refractive index of the TOP layer increases with increasing lamp intensity (irradiation intensity). This indicates that the photodensification reaction of polysilazane is highly dependent on lamp intensity.

[0150] Normally, if the photodensification reaction of polysilazane were a single-photon reaction, it could be considered independent of lamp intensity (irradiation intensity), and the refractive index could be determined based on the cumulative light intensity. However, this experiment shows that the photodensification reaction is highly dependent on lamp intensity (irradiation intensity), thus indicating that the photodensification reaction of polysilazane is not a single-photon reaction, but rather a reaction involving other photons.

[0151] Under the same cumulative light intensity, it was shown that the higher the lamp intensity (irradiation intensity), the higher the refractive index of the TOP layer. Specifically, the increase in refractive index was observed at a lamp intensity of 290 mW / cm². 2 As a boundary, it has a sharp acceleration effect. Therefore, it is shown that at a lamp intensity (irradiation intensity) of 290 mW / cm², 2 At the above levels, polysilazane can be effectively high-density.

[0152] Furthermore, the time required for the refractive index of the TOP layer to become equal under different lamp intensities (irradiation intensities) was compared, with a lamp intensity (irradiation intensity) of 103 mW / cm². 2 The refractive index of the top layer in Comparative Example 1 is 1.78 (cumulative light intensity 24 J / cm). 2 Under the baseline conditions, it took 234 seconds in Comparative Example 1, while the lamp intensity (irradiation intensity) was 328 mW / cm². 2 In Example 3, the cumulative light intensity is 6 J / cm when the refractive index of the TOP layer is 1.78. 2 Therefore, it only takes 19 seconds.

[0153] Therefore, by increasing the lamp intensity (irradiation intensity) by about 3.2 times, the irradiation time of Example 3 can be shortened to 1 / 12 of that of Comparative Example 1, that is, the time is shortened to only 8% of that of Comparative Example 1.

[0154] Furthermore, if we compare it with the TOP layer, which has a higher refractive index of 1.81 due to the densification process of the cured film, then compared with Comparative Example 1 (cumulative light intensity 72 J / cm²), it is significantly higher. 2 Example 3 (cumulative light intensity 12 J / cm) 2 The irradiation time is reduced to 1 / 19, that is, reduced to 5% of the time, which is a significant reduction compared to the past.

Claims

1. A method for producing a modified polysilazane cured film, characterized by, comprising: a coating step of coating a solution containing a polysilazane compound represented by the following general formula (1) on a substrate to form a coated article; and a curing step of irradiating Xe excimer light to the coated article to modify the polysilazane compound to form a cured film of modified polysilazane compound, The illuminance of the Xe excimer light in the curing step is 280 to 450 mW / cm2 2 , 【General Formula 1】 In the general formula (1), x is an integer of 20 < x ≤ 1000, and y is an integer of 0 ≤ y < (x / 10).

2. The method for producing a modified polysilazane cured film according to claim 1, characterized by The ratio (N+O) / Si of the total of the number of nitrogen atoms and the number of oxygen atoms of the modified polysilazane compound to the number of silicon atoms is 0.9 to 1.

1.

3. The method for producing a modified polysilazane cured film according to claim 1, characterized by, The polysilazane compound is a perhydropolysilazane.

4. The method for producing a modified polysilazane cured film according to claim 1, characterized by The cumulative light quantity of the Xe excimer light irradiated to the coated article is 1000 to 10000 mJ / cm2 2 .

5. The method for producing a modified polysilazane cured film according to claim 1, characterized by The Xe excimer light is irradiated in a nitrogen atmosphere having an oxygen concentration of 0.1% or less.

6. The method for producing a modified polysilazane cured film according to claim 1, characterized by The substrate is an organic resin film.

7. The method for producing a modified polysilazane cured film according to claim 1, wherein The substrate is a polyimide film or a polyethylene terephthalate film.

8. A modified polysilazane cured film characterized by, is obtained by the production method of the modified polysilazane cured film according to any one of claims 1 to 7.

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