Photocurable composition
阅读说明：本技术 光固化性组合物 (Photocurable composition ) 是由 李飞 刘卫军 于 2020-03-02 设计创作，主要内容包括：光固化性组合物可包含可聚合的材料和光引发剂,其中至少90重量％的可聚合的材料可包含丙烯酸酯单体,所述单体包括芳族基团。光固化性组合物可具有不大于15mPa·s的粘度,固化之后光固化性组合物的总碳含量可为至少73％,和大西数可不大于3.0。(The photocurable composition may comprise a polymerizable material and a photoinitiator, wherein at least 90% by weight of the polymerizable material may comprise an acrylate monomer comprising an aromatic group. The photocurable composition may have a viscosity of no greater than 15 mPa-s, the total carbon content of the photocurable composition after curing may be at least 73%, and the darcy number may be no greater than 3.0.)
1. A photocurable composition comprising a polymerizable material and a photoinitiator, wherein
At least 90% by weight of the polymerizable material comprises an acrylate monomer comprising an aromatic group;
and the total carbon content of the photocurable composition after curing is at least 70%.
2. The photocurable composition of claim 1, wherein at least 99% by weight of the polymerizable material comprises a monomer compound comprising an aromatic ring structure.
3. The photocurable composition of claim 1, wherein at least 10% by weight of the polymerizable material is a difunctional acrylate containing aromatic groups.
4. The photocurable composition of claim 3, wherein the aromatic group-containing difunctional acrylate monomer is bisphenol A dimethacrylate (BPADMA).
5. The photocurable composition of claim 1, wherein polymerizable material comprises at least three different types of acrylate monomers, said monomers comprising aromatic groups.
6. The photocurable composition of claim 1, wherein the polymerizable material comprises at least 3 wt% divinylbenzene.
7. The photocurable composition of claim 1, wherein the polymerizable material comprises at least two monomer types selected from the group consisting of: benzyl Acrylate (BA), Benzyl Methacrylate (BMA), 1-naphthyl methacrylate (1-NMA), bisphenol A dimethacrylate (BPADMA), Divinylbenzene (DVB) or 1-naphthyl acrylate (1-NA).
8. The photocurable composition of claim 7, wherein the polymerizable material comprises at least BA and BPADMA.
9. The photocurable composition of claim 8, wherein the polymerizable material further comprises 1-NA or 1-NMA.
10. The photocurable composition of claim 1, wherein the viscosity of the photocurable composition is not greater than 15 mPa-s.
11. A laminate comprising a substrate and a photocurable layer covering the substrate, wherein the photocurable layer comprises a total carbon content of at least 73% and an radix of not greater than 3.0.
12. The laminate as set forth in claim 11, wherein the photocurable layer is made by UV curing a photocurable composition comprising a polymerizable material and a photoinitiator, wherein at least 90% by weight of the polymerizable material comprises an acrylate monomer comprising an aromatic group.
13. The laminate of claim 11, wherein the photocurable layer has a weight loss of no greater than 5.5% after heating at 250 ℃ for 60 seconds.
14. The laminate of claim 11, wherein the photocurable layer has a hardness of at least 0.3 GPa.
15. The laminate of claim 11, wherein the photocurable layer has a storage modulus of at least 4.5 GPa.
16. A method of forming a photocurable layer on a substrate, comprising:
applying a layer of a photocurable composition on a substrate, wherein the photocurable composition comprises a polymerizable material and a photoinitiator, wherein at least 90% by weight of the polymerizable material comprises an acrylate monomer, the monomer comprising an aromatic group;
contacting a photocurable composition with a cover plate;
irradiating the photocurable composition with light to form a photocurable layer; and
the cover sheet is removed from the photo-set product,
wherein the light curable layer has a total carbon content of at least 70%.
17. The method according to claim 16, wherein the photocurable composition has a viscosity of not more than 15 mPa-s.
18. The method of claim 16, wherein the polymerizable material comprises at least two monomer types selected from the group consisting of: benzyl Acrylate (BA), Benzyl Methacrylate (BMA), 1-naphthyl methacrylate (1-NMA), bisphenol A dimethacrylate (BPADMA), Divinylbenzene (DVB) or 1-naphthyl acrylate (1-NA).
19. The method of claim 16, wherein the photocurable layer has a radix of not greater than 3.0.
20. The method of claim 16, wherein the photocurable layer has a hardness of at least 0.3 GPa.
Technical Field
The present disclosure relates to a photocurable composition, and particularly to a photocurable composition for inkjet adaptive planarization.
Background
Inkjet Adaptive Planarization (IAP) is a method of planarizing the surface of a substrate, such as a wafer containing circuits, by ejecting droplets of a photocurable composition on the surface of the substrate and bringing a flat cover plate into direct contact with the added liquid to form a flat liquid layer. The flat liquid layer is typically solidified under UV light exposure and after removal of the cover plate a planar surface is obtained, which may be subjected to subsequent processing steps, such as baking, etching and/or further deposition steps. There is a need for improving IAP materials to bring about planar photocurable layers with high etch resistance, high mechanical strength and good thermal stability.
Disclosure of Invention
In one embodiment, a photocurable composition may comprise a polymerizable material and a photoinitiator, wherein at least 90% by weight of the polymerizable material comprises an acrylate monomer comprising an aromatic group; and the total carbon content of the photocurable composition after curing may be at least 70%.
In one aspect, at least 99% by weight of the polymerizable material can comprise monomers comprising an aromatic ring structure.
In another aspect, at least 10 wt% of the polymerizable material can be a difunctional acrylate containing aromatic groups.
In a further aspect, the difunctional acrylate monomer containing an aromatic group can be bisphenol a dimethacrylate (BPADMA).
In still further aspects, the polymerizable material can include at least three different types of acrylate monomers, wherein each of the at least three different types of acrylate monomers contains an aromatic group.
In another aspect, the polymerizable material may include at least two monomer types selected from the group consisting of: benzyl Acrylate (BA), Benzyl Methacrylate (BMA), 1-naphthyl methacrylate (1-NMA), bisphenol A dimethacrylate (BPADMA), Divinylbenzene (DVB) or 1-naphthyl acrylate (1-NA). In particular aspects, the photocurable composition can include at least BA and BPADMA. In another particular aspect, the photocurable composition can include at least BA and BPADMA and additionally 1-NA or 1-NMA.
In another particular aspect, the polymerizable material can include at least 3 wt.% divinylbenzene.
In still further aspects, the photocurable compositions of the present disclosure can have a viscosity of no greater than 15 mPa-s.
In one embodiment, a laminate can comprise a substrate and a photocurable layer overlying the substrate, wherein the photocurable layer comprises a total carbon content of at least 73% and a number of western countries (Ohnishi number) of not greater than 3.0.
In one aspect, the photocurable layer of the laminate may be made by UV curing a photocurable composition, wherein the photocurable composition comprises a polymerizable material and a photoinitiator, wherein at least 90% by weight of the polymerizable material comprises an acrylate monomer comprising an aromatic group.
In another aspect, the photocurable layer of the laminate can have a weight loss of no greater than 5.5% after heating at 250 ℃ for 60 seconds.
In further aspects, the photocurable layer of the laminate can have a hardness of at least 0.3 GPa.
In still further aspects, the photocurable layer can have a storage modulus of at least 4.5 GPa.
In another embodiment, a method of forming a photocurable layer on a substrate may include: applying a layer of a photocurable composition on a substrate; contacting the curable composition with a cover plate; irradiating the photocurable composition with light to form a photocurable layer; and removing the cover plate from the photo-set product. The photocurable composition of the method may comprise a polymerizable material and a photoinitiator, wherein at least 90% by weight of the polymerizable material comprises an acrylate monomer comprising an aromatic group. In one aspect, the total carbon content of the photocurable layer can be at least 70%.
On the other hand, the photocurable composition used in the method of forming a photocurable layer may have a viscosity of not more than 15mPa · s.
In further aspects, the polymerizable material used in the method of forming a photocurable layer may include at least two monomer types selected from the group consisting of: benzyl Acrylate (BA), Benzyl Methacrylate (BMA), 1-naphthyl methacrylate (1-NMA), bisphenol A dimethacrylate (BPADMA), Divinylbenzene (DVB) or 1-naphthyl acrylate (1-NA).
In one aspect, the photocurable layer obtained by the method can have a radix of not greater than 3.0.
In yet another aspect, the photocurable layer of the method can have a hardness of at least 0.3 GPa.
Drawings
Embodiments are illustrated by way of example and not limitation in the figures.
Fig. 1 includes a graph illustrating the amount of material removed by oxygen etching from a cured sample layer according to an embodiment and comparing it to material removal during oxygen etching of a commercial resist sample used for nanoimprint lithography (NIL).
Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
Detailed Description
The following description is provided to aid in understanding the teachings disclosed herein and will focus on specific embodiments and implementations of the teachings. This focus is provided to help describe the teachings and should not be construed as limiting the scope or applicability of the teachings.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent not described herein, many details regarding specific materials and processing acts are conventional and may be found in textbooks and other sources within the imprinting and lithography arts.
As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited to only those features but may include other features not expressly listed or inherent to such process, method, article, or apparatus.
As used herein, and unless expressly stated to the contrary, "or" means including "or" and not excluding "or". For example, either of the following satisfies condition a or B: a is true (or present) and B is false (or not present), a is false (or not present) and B is true (or present), and both a and B are true (or present).
In addition, "a" or "an" is used to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. The description is to be understood as including one or at least one and the singular also includes the plural unless it is obvious that it is different.
The present disclosure relates to photocurable compositions comprising polymerizable materials that include a plurality of acrylate monomers having aromatic groups. The photocurable composition may be particularly suitable for use in IAPs for preparing planar cured layers with surprisingly high etch stability, good mechanical strength and thermal stability.
In one embodiment, at least 90% by weight of the polymerizable material may comprise acrylic monomers containing aromatic groups in their chemical structure. In further aspects, the amount of aromatic group-containing acrylic monomer can be at least 92 wt%, or at least 94 wt%, or at least 96 wt%, or at least 98 wt%, or at least 99 wt%, or 100 wt%, based on the total weight of the polymerizable material.
Some non-limiting examples of acrylic monomers comprising aromatic groups may be: benzyl Acrylate (BA), Benzyl Methacrylate (BMA), 1-naphthyl methacrylate (1-NMA), bisphenol A dimethacrylate (BPADMA), 1-naphthyl acrylate (1-NA), 2-naphthyl acrylate (2-NA), 9-bis [4- (2-acryloyloxyethoxy) phenyl ] fluoro (A-BPEF), 9-fluorene methacrylate (9-FMA), 9-fluorene acrylate (9-FA), o-phenylbenzyl acrylate (o-PBA), bisphenol A diacrylate (BPADA), or acrylic acid, 1,1' - [1,1' -binaphthyl ] -2,2' -diyl ester (BNDA).
In one embodiment, at least 10% by weight of the polymerizable material may comprise a difunctional acrylate containing an aromatic group. In certain particular aspects, the difunctional acrylate containing an aromatic group can be bisphenol a dimethacrylate (BPADMA).
In another particular embodiment, monofunctional, difunctional or trifunctional monomers, which do not have acrylate groups but also contain aromatic groups, may be contained in the polymerizable material. Non-limiting examples of such monomers can be methacrylates, vinyl ethers, vinyl esters, and other olefin monomers, substituted with aromatic groups. In particular aspects, divinylbenzene can be part of a polymerizable material that includes a benzene ring linked to two vinyl groups as reactive functional groups. In one aspect, the amount of divinylbenzene in the polymerizable material can be at least 5 weight percent based on the total amount of polymerizable material.
In another embodiment, the polymerizable material can include at least two different types of acrylate monomers including aromatic groups, such as at least three, at least four, or at least five different types of acrylate monomers including aromatic groups.
The polymerizable material may also include one or more monomers, oligomers, or polymers that do not contain aromatic groups and include single or multiple functional groups per monomer unit. In one embodiment, the amount of polymerizable compound excluding aromatic groups may be between 0.1 wt.% and 10 wt.%, based on the total weight of polymerizable material, for example between 1 wt.% and 8 wt.%, or between 2 wt.% and 5 wt.%, based on the total weight of polymerizable material. Some non-limiting examples of polymerizable compounds that do not include aromatic groups may be: 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate, methyl acrylate, isobornyl acrylate, stearyl acrylate, or any combination thereof.
It is important for the selection of monomers to maintain the low viscosity aspect of the polymerizable composition prior to curing. In one embodiment, the viscosity of the curable composition can be no greater than 20 mPas, such as no greater than 15 mPas, no greater than 12 mPas, no greater than 10 mPas, no greater than 9 mPas, or no greater than 8 mPas. In other particular embodiments, the viscosity may be at least 2 mPas, such as at least 3 mPas, at least 4 mPas or at least 5 mPas. In a particularly preferred aspect, the curable composition may have a viscosity of not more than 15mPa · s. As used herein, all viscosity values relate to viscosity measured by the Brookfield method at a temperature of 23 ℃ using a Brookfield viscometer at 200 rpm.
The amount of polymerizable material in the photocurable composition can be at least 5 wt%, based on the total weight of the composition, for example at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 30 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, or at least 90 wt%, or at least 95 wt%. In another aspect, the amount of polymerizable material can be no greater than 98 wt%, such as no greater than 97 wt%, no greater than 95 wt%, no greater than 93 wt%, no greater than 90 wt%, or no greater than 85 wt%, based on the total weight of the photocurable composition. The amount of polymerizable material can be a value between any of the minimum and maximum values noted above. In particular aspects, the amount of polymerizable compound can be at least 70 wt% and no greater than 98 wt%.
The photocurable composition may further contain one or more optional additives. Non-limiting examples of optional additives may be stabilizers, dispersants, solvents, surfactants, inhibitors, or any combination thereof.
It has surprisingly been found that by selecting a specific combination of polymerizable monomers containing aromatic groups, photocurable compositions can be made to have a desired low viscosity of less than 10mPa · s, but results in cured materials having high etch resistance, low shrinkage during UV curing, and excellent mechanical and thermal stability.
In one embodiment, the photocurable composition may be applied on a substrate to form a photocurable layer. As used herein, the combination of a substrate and a photocurable layer overlying the substrate is referred to as a laminate.
In an aspect, the photocurable layer of the laminate can have a radix of not greater than 3.0, such as not greater than 2.9, not greater than 2.8, not greater than 2.7, or not greater than 2.6. In another aspect, the grand west number can be at least 1.8, such as at least 1.9, at least 2.0, at least 2.1, at least 2.2, or at least 2.3.
In another aspect, the photocurable layer of the laminate may have a hardness of at least 0.3GPa, such as at least 0.32GPa, at least 0.34GPa, at least 0.36GPa, or at least 0.38 GPa.
In further aspects, the storage modulus of the photocurable layer can be at least 4.5GPa, such as at least 4.6GPa, at least 4.7GPa, at least 4.8GPa, at least 4.9GPa, at least 5.0GPa, or at least 5.1 GPa.
The photocurable layer of the laminate may also have good thermal stability. In one aspect, the photocurable layer can have a weight loss of no greater than 6%, such as no greater than 5.5%, no greater than 5.0%, no greater than 4%, no greater than 3%, or no greater than 2.5%, if heated to a temperature of 250 ℃ at a rate of 20 ℃/min and held at 250 ℃ for 60 seconds.
The selection of monomers comprising aromatic groups of the photocurable material may result in a high carbon content in the photocurable layer. In one embodiment, the carbon content of the photocurable layer can be at least 70%, such as at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, or at least 77%. In a particular aspect, the carbon content is at least 73%.
In further aspects, the glass transition temperature of the photocurable layer of the laminate can be at least 80 ℃, e.g., at least 85 ℃, at least 90 ℃, at least 100 ℃, at least 110 ℃, at least 120 ℃, or at least 130 ℃.
In particular embodiments, the photocurable layer can have a carbon content of at least 70%, a glass transition temperature of at least 85 ℃, and a radix of not greater than 3.0.
The present disclosure also relates to methods of forming a photocurable layer. The method may comprise applying a layer of the photocurable composition described above on a substrate, bringing the photocurable composition into contact with the template or cover plate; irradiating the photocurable composition with light to form a photocurable layer; and removing the template or cover sheet from the photocurable layer.
The substrate and solidified layer may be subjected to additional processing, such as an etching process, to transfer an image to the substrate, which corresponds to a pattern in one or both of the solidified layer and/or the pattern layer below the solidified layer. The substrate may also be subjected to known steps and processes for device (article) fabrication including, for example, curing, oxidation, layer formation, deposition, doping, planarization, etching, formable material removal, cutting, bonding, and packaging, among others.
The photocurable layer may also be used as an interlayer insulating film of a semiconductor device such as LSI, system LSI, DRAM, SDRAM, RDRAM, or D-RDRAM, or as a resist film used in a semiconductor manufacturing process.
As further illustrated in the examples, it has surprisingly been found that a specific combination of polymerizable monomers containing aromatic groups in the photocurable composition may have properties that are very suitable especially for IAP processing. The photocurable composition of the present disclosure may have a desired low viscosity of less than 15mPa · s and may form a photocurable layer having high mechanical strength, high thermal stability, and low shrinkage.
Examples
The following non-limiting examples illustrate the concepts as described herein.
Example 1
Preparation of Photocurable IAP compositions
Ten photocurable compositions (samples S1 to S10) were prepared by combining for each sample at least three different types of polymerizable monomers containing an aromatic group (see table 1), a photoinitiator (2.88 wt.% Irgacure 819 from LabNetworks) and two surfactants (0.96 wt.% of a mixture of FS2000M1 from Daniel lab LLC and Chemguard S554-100 from Chemguard). The following polymerizable monomers containing aromatic groups were used to prepare the photocurable composition: benzyl Acrylate (BA), 1-naphthyl methacrylate (1-NMA), 1-naphthyl acrylate (1-NA), bisphenol A dimethacrylate (BPADMA), and Divinylbenzene (DVB), 9-bis [4- (2-acryloyloxyethoxy) phenyl ] fluorine (A-BPEF), 9-fluorene methacrylate (9-FMA), 9-fluorene acrylate (9-FA), o-phenylbenzyl acrylate (o-PBA), bisphenol A diacrylate (BPADA), or acrylic acid, 1,1' - [1,1' -binaphthyl ] -2,2' -diyl ester (BNDA). The specific monomer types and monomer amounts for samples S1 through S10 are summarized in table 1.
TABLE 1
Sample (I)
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
DVB
4.81
BA
24.04
48.08
48.08
48.08
48.08
48.08
48.08
48.08
48.08
48.08
BMA
19.23
o-PBA
28.85
28.85
1-NMA
28.25
1-NA
28.85
28.85
28.85
28.85
28.85
2-NA
28.85
BPADMA
19.23
19.23
19.23
19.23
19.23
19.23
A-BPEF
19.23
9-FMA
28.85
9-FA
28.85
BNDA
19.23
BPADA
19.23
19.23
The tested properties such as viscosity, UV shrinkage during curing, glass transition temperature Tg after curing, carbon number, and darcy number of samples S1-S10 are summarized in table 2. After applying a liquid film of the photocurable composition to a thickness of about 100nm on a glass substrate and subjecting the liquid film to 4mW/cm2And curing it for 600 seconds (which corresponds to 2.4J/cm)2Curing energy amount) to perform curing.
Table 2 also includes data from thermogravimetric analysis (TGA) of several samples by measuring the weight loss of the sample during heating at a rate of 20 ℃/minute up to 250 ℃ and holding the temperature at this temperature for 60 seconds. This investigation was conducted in order to simulate the wafer baking process. Without being bound by theory, the change in weight loss of the sample during heat treatment at 250 ℃ may indicate that the degree of polymerization of the monomer is greater in samples with lower weight loss (e.g., samples S2, S3, and S9) than in samples with higher weight loss (e.g., S1).
TABLE 2
The viscosity of the samples was measured at 23 ℃ using a Brookfield viscometer LVDV-II + Pro at 200rpm, spindle size # 18. For viscosity testing, about 6-7mL of sample fluid was added to the sample chamber, sufficient to cover the spindle head. For all viscosity tests, at least three measurements were made and the average was calculated.
Shrinkage measurements were made using an Anton Paar MCR-301 rheometer coupled to a UV cure system and heater. For the test, a 7 μ Ι drop of test sample was added to the plate and the temperature control hood was released to isolate the drop from the measurement device. The sample volume is designed to obtain a thickness (hereinafter also referred to as height) of the sample layer slightly above 0.1 mm. By presetting the target height to 0.1mm, the measuring device is moved down to the set value, causing excess resist to flow off the plate. This ensures that the exact height of the liquid resist before curing is 0.1 mm. Thereafter, 4mW/cm at 365nm was used2The resist was cured for 600 seconds. After the resist was cured, the height was measured again and the linear shrinkage was calculated according to equation (1).
Example 2
The mechanical properties of the photo-cured samples S1 and S2 described in example 1 were tested by nanoindentation using a Hysitron TI 950 nano in-situ meter.
A summary of the average contact depth, average storage modulus and average hardness of the tests is shown in table 3.
As a control, comparative sample C1, which is a typical resist material used for nanoimprint lithography (NIL), was tested. Comparative sample C1 contained the following components: isobornyl acrylate (IBOA) in an amount of 33.3 wt.%, dicyclopentenyl acrylate (DCPA) in an amount of 19.4 wt.%, Benzyl Acrylate (BA) in an amount of 22.2 wt.%, neopentyl glycol diacrylate (a-NPG) in an amount of 18.5 wt.%, photoinitiator Irgacure 907 in an amount of 0.925 wt.%, Irgacure 651 in an amount of 1.85 wt.%, and surfactant in an amount of 3.79 wt.%. Comparative sample C1 had a viscosity of 7mPa s, a UV shrinkage during curing of 4.2%, a carbon content of 71%, a glass transition temperature of 90 ℃, and a darcy number of 3.27.
The results show that both samples S1 and S2 have higher hardness and higher storage modulus than the comparative sample C1.
TABLE 3
The storage modulus and glass transition temperature were measured using an Anton-Paar MCR-301 rheometer connected to a Hamamatsu lightning LC8 UV source. 1.0mW/cm at 365nm, controlled by a Hamamatsu 365nm UV power meter2The sample is irradiated with UV intensity of (1). The rheometer was controlled using software named RheoPlus and data analysis was performed. The temperature was controlled by juebo F25-ME water unit and set to 23 ℃ as starting temperature. For each sample test, 7 μ l of resist sample was added to the glass plate directly below the measurement system of the rheometer. The distance between the glass plate and the measuring device was reduced to a gap of 0.1mm before the start of irradiation with UV. The UV irradiation exposure was continued until the storage modulus reached a plateau and the height of the plateau was recorded as the storage modulus listed in table 3.
After completion of the UV curing, the change of storage modulus with temperature was measured by controlled heating to increase the temperature of the cured sample to obtain the glass transition temperature Tg. As glass transition temperature TgConsidered as the temperature corresponding to the maximum value of the tangent (θ).
The hardness was calculated from the load curve measured by indentation to 200nm using a Hysitron TI 950 nm in situ gauge using a displacement controlled load function. During indentation, the force is measured, from which a load curve can be obtained. Hardness (H) was calculated according to the following equation: h ═ Pmax/AcIn which P ismaxIs the maximum applied force, and AcIs the contact area determined by the tip area function.
Example 3
Examination of etching resistance
For the etch resistance study, a liquid film about 100nm thick was printed on a blank template of an Imprio I300 tool for each sample. The printed liquid film is photocured and thereafter subjected to oxygen etching. The Etch process was performed using a trio Oracle Etch system with the following plasma chemistry: o excited using RIE at 10mtorr2An argon plasma. The total processing time for each sample was about 60 seconds.
After the etching treatment, the amount of material removed during etching in the thickness direction of the 100nm film was measured.
A summary of the etch test results is shown in table 4 and fig. 1. It can be seen that sample S1 is more resistant to oxygen etching than comparative sample C1. Specifically, sample S1 reached an etch depth of about 43nm (material removal in the thickness direction of the film), while comparative sample C1 was less etch-resistant exposed and lost about 55nm in depth. Thus, sample S1 is more resistant to 21.4% etching than comparative sample C1.
Very similar etch behavior can be observed after subjecting the cured 100nm thick layer to a bake treatment at 250 ℃ for 90 seconds, but before etching. While sample S1 lost about 41nm of material in the thickness direction of the film during the oxygen etch, comparative sample C1 had a material removal of about 53 nm.
The results of the etching experiments correspond to the calculated Dawest number of the test samples. The sample having high etching resistance has a radix number of less than 3, particularly not more than 2.6 (see S1 and S3), and the comparative sample C1 having lower etching resistance has a radix number of more than 3 (see C1).
The Darcy number (ON) is known to be an empirical parameter and is calculated as the total number of atoms in the polymer repeat unit (N)t) Divided by the number of carbon atoms (Nc) and the number of oxygen atoms (N) in the unitO) The ratio of the difference, ON ═ Nt/(NC–NO). For the calculation of the Daxiety number, it is assumed that the cured material contains 100% by weight of polymerized monomer units formed by addition polymerization (no atom loss during polymerization).
TABLE 4
Example 4
Comparison of different curing intensities with respect to thickness change after baking and UV shrinkage
Similar to example 1, a 100nm thick film of sample S2 was formed and cured at different UV intensities (see Table 4) until 2.4J/cm was reached2Total dose curing energy of. After curing, the cured sample was subjected to heat treatment at 250 ℃ for 90 seconds (baking), and the change in thickness of the sample layer was measured. As can be seen in Table 4, the lowest UV curing intensity (4 mW/cm)2) Causing the lowest layer thickness change during the baking process (6.5%). Increasing UV intensity to 15mW/cm2Causing an additional increase (7.98%) in the thickness reduction of about 1.5%.
TABLE 5
It was also investigated that if the light intensity applied during the curing of sample S2 had an effect on the shrinkage of the photocurable composition after UV curing. As can be seen in Table 5, the light intensity was from 4mW/cm2Up to 100mW/cm2The change in (b) has only a very small effect on the shrinkage results. The difference in applied light intensity shrinkage is less than 1% taking into account the difference.
TABLE 6
The definitions and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The specification and illustrations are not intended to serve as an exhaustive or comprehensive description of all the elements and features of apparatus and systems that utilize the structures or methods described herein. Separate embodiments may also be provided in combination in a single embodiment, and conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, reference to a value stated in a range includes each value within that range. Many other embodiments may be apparent to the skilled person only after reading this specification. Other embodiments may be utilized and derived from the disclosure, such that a structural substitution, logical substitution, or another change may be made without departing from the scope of the disclosure. The present disclosure is, therefore, to be considered as illustrative and not restrictive.
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