Patent Application
20220162118
The present disclosure related to a method for preparing a cover substrate. More specifically, the present disclosure relates to a method for preparing a cover substrate with hydrophobicity.
The common anti-smudge or anti-fingerprint materials are the organic polymers with fluorine functional groups. Conventionally, these materials are bonded with the material of the substrate via high temperature dehydration reaction by the spray or evaporation process.
When the anti-smudge or anti-fingerprint layer is formed by the spray process, additional spray and oven machines have to be used for surface-treating the anti-reflection film.
When the anti-smudge or anti-fingerprint layer is formed by the evaporation process, even though the evaporation device can be integrated into the equipment for forming the anti-reflection film, the equipment has to be expanded and the high-temperature manufacturing process is still required. In addition, the anti-smudge or anti-fingerprint materials may adhere onto the chamber and the jig during the evaporation process, resulting in the pollution or defect on the product.
Therefore, it is desirable to provide a novel method to solve the problem of the spray or evaporation process.
The present disclosure provides a method for preparing a cover substrate, wherein the method comprises the following steps: providing a substrate with an anti-reflection film formed thereon, wherein the anti-reflection film comprises a first layer with low refractive index; and treating the first layer of the anti-reflection film with fluoride-based plasma to form a hydrophobic layer on the first layer.
Other novel features of the disclosure will become more apparent from the following detailed description.
Different embodiments of the present disclosure are provided in the following description. These embodiments are meant to explain the technical content of the present disclosure, but not meant to limit the scope of the present disclosure. A feature described in an embodiment may be applied to other embodiments by suitable modification, substitution, combination, or separation.
It should be noted that, in the present specification, when a component is described to comprise an element, it means that the component may comprise one or more of the elements, and it does not mean that the component has only one of the element, except otherwise specified.
Moreover, in the present specification, the ordinal numbers, such as “first” or “second”, are used to distinguish a plurality of elements having the same name, and it does not means that there is essentially a level, a rank, an executing order, or an manufacturing order among the elements, except otherwise specified. A “first” element and a “second” element may exist together in the same component, or alternatively, they may exist in different components, respectively. The existence of an element described by a greater ordinal number does not essentially means the existence of another element described by a smaller ordinal number.
In the present specification, except otherwise specified, the feature A “or” or “and/or” the feature B means the existence of the feature A, the existence of the feature B, or the existence of both the features A and B. The feature A “and” the feature B means the existence of both the features A and B. The term “comprise(s)”, “comprising”, “include(s)”, “including”, “have”, “has” and “having” means “comprise(s)/comprising but is/are/being not limited to”.
Moreover, in the present specification, the terms, such as “top”, “upper”, “bottom”, “front”, “back”, or “middle”, as well as the terms, such as “on”, “above”, “over”, “under”, “below”, or “between”, are used to describe the relative positions among a plurality of elements, and the described relative positions may be interpreted to include their translation, rotation, or reflection.
Furthermore, the terms recited in the specification and the claims such as “above”, “over”, or “on” are intended not only directly contact with the other element, but also intended indirectly contact with the other element. Similarly, the terms recited in the specification and the claims such as “below”, or “under” are intended not only directly contact with the other element but also intended indirectly contact with the other element.
In the present specification, except otherwise specified, the terms (including technical and scientific terms) used herein have the meanings generally known by a person skilled in the art. It should be noted that, except otherwise specified in the embodiments of the present disclosure, these terms (for example, the terms defined in the generally used dictionary) should have the meanings identical to those known in the art, the background of the present disclosure or the context of the present specification, and should not be read by an ideal or over-formal way.
In the step (S11), as shown in
In the step (S12), as shown in
Hereinafter, the process for forming the anti-reflection film 2 is described in detail.
As shown in
In the present disclosure, the anti-reflection film 2 may be formed on the substrate 1 by a physical vapor deposition (PVD) process. For example, the anti-reflection film 2 may be formed by a sputtering process, but the present disclosure is not limited thereto.
The substrate 1 is placed in a chamber for PVD, and the substrate 1 is cleaned with plasma (for example, argon plasma) before the deposition process. The deposition process is briefly described below.
Firstly, additional energy is provided to cause gas discharge phenomenon, and the gas (for example, argon) is ionized to form charged ions. The charged ions are accelerated by an electric field and hit a target (i.e., Bombard) to shoot out a trace amount of target atoms and simultaneously generate secondary electrons. The target atoms reach the surface 11 of the substrate 1 with a certain kinetic energy to form a film comprising target elements on the surface 11 of the substrate 1. Then, oxygen, nitrogen or a combination thereof is introduced into the chamber to react with the target atoms deposited on the surface 11 of the substrate 1 to form an oxide, a nitride or an oxynitride of the target elements.
Then, the aforesaid deposition process is repeated to form plural layers until the anti-reflection film 2 has a desired thickness. In the present disclosure, the thickness T of the anti-reflection film 2 may be ranged from 500 nm to 1500 nm (500 nm≤T≤1500 nm). For example, the thickness T of the anti-reflection film 2 may be: 700 nm≤T≤1300 nm, 800 nm≤T≤1200 nm, 900 nm≤T≤1100 nm or 950 nm≤T≤1050 nm, but the present disclosure is not limited thereto.
In the present embodiment, as shown in
In the present embodiment, the first layer 21 and the third layer 23 may respectively comprise silicon oxide (SiO2), and the refractive index of silicon oxide is about 1.45˜1.48. The second layer 22 and the fourth layer 24 may respectively comprise niobium oxide (Nb2O5), titanium oxide (TiO2), tantalum oxide (Ta2O5) or silicon oxynitride (SiONx), and the materials for the second layer 22 and the fourth layer 24 can be the same or different. The refractive index of niobium oxide is about 2.1˜2.4, the refractive index of titanium oxide is about 2.2˜2.5, the refractive index of tantalum oxide is about 2˜2.3, and the refractive index of silicon oxynitride is about 1.6˜1.7.
Hereinafter, the process for forming the hydrophobic layer 3 is described in detail.
As shown in
In the present embodiment, the power (W1) of the microwave used for generating the fluoride-based plasma may be, for example, ranging from 1200 W to 1800 W (1200 W≤W1≤1800 W). The gas flow (R) of the fluoride-based compound for forming the fluoride-based plasma may be, for example, ranged from 400 sccm to 600 sccm (400 sccm≤R≤600 sccm). In addition, the first layer 21 of the anti-reflection film 2 is treated with the fluoride-based plasma at a pressure (P), for example, ranging from 90 Pa to 150 Pa (90 Pa≤P≤150 Pa). However, the parameters used for forming the anti-reflection film 2 are not limited to those described above, and may be adjusted according to the need.
In the present embodiment, the fluoride-based compound used for generating the fluoride-based plasma may be C1-8 alkane substituted with fluorine, C2-8 alkene substituted with fluorine, C2-8 alkyne substituted with fluorine, nitrogen trifluoride, sulfur hexafluoride, or a combination thereof. In some embodiments of the present disclosure, the fluoride-based compound may be C1-6 alkane substituted with fluorine, C2-6 alkene substituted with fluorine, C2-6 alkyne substituted with fluorine, nitrogen trifluoride, sulfur hexafluoride, or a combination thereof. In further some embodiments of the present disclosure, the fluoride-based compound may be C1-4 alkane substituted with fluorine, C2-4 alkene substituted with fluorine, C2-4 alkyne substituted with fluorine, nitrogen trifluoride, sulfur hexafluoride, or a combination thereof. Herein, alkane substituted with fluorine refers to the alkane in which one to all of the hydrogen atoms in the alkane are substituted with fluorine atoms. Similarly, alkene substituted with fluorine refers to the alkene in which one to all of the hydrogen atoms in the alkene are substituted with fluorine atoms. Similarly, alkyne substituted with fluorine refers to the alkyne in which one to all of the hydrogen atoms in the alkyne are substituted with fluorine atoms. Specific examples of the fluoride-based compound capable of generating the fluoride-based plasma may include, but are not limited to, CF4, CHF3, C2F6, C3F8, C4F8, NF3 or SF6.
In the present embodiment, a radio-frequency bias may be provided when treating the first layer 21 of the anti-reflection film 2 with the fluoride-based plasma. The radio-frequency bias may lead the fluorine-containing radicals in the direction toward the first layer 21, and thus the uniformity of the formed hydrophobic layer 3 may be improved. The radio-frequency bias may be provided by applying on a stage (not shown in the figure) for carrying the substrate 1. In addition, the radio-frequency bias is provided with a radio-frequency having a power (W2), for example, ranged from 200 W to 300 W (200 W≤W2≤300 W); but the present disclosure is not limited thereto.
After the aforementioned process, the hydrophobic layer 3 is formed on the anti-reflection film 2. Herein, the formed hydrophobic layer 3 has a contact angle (θ) over than 100 degrees (θ>100°). For example, the contact angle (θ) of the hydrophobic layer 3 may be: 100°<0<150°, 100°21 θ<140°, 100°<θ<130°, 100°<θ<120°, or 100°<θ<115°. The fluorine-containing substituents bonding to the silicon elements of the silicon oxide can provide hydrophobicity, so the hydrophobic layer 3 may have the anti-smudge or anti-fingerprint effect.
As shown in
In the present test example, the cover substrate with the hydrophobic layer (as shown in
Herein, as shown in
Then, the charged ions of argon were accelerated by the electric field and hit the Si target to eject Si atoms and generate secondary electrons at the same time. The Si atoms reached the fourth layer 24 and deposited to form a Si film. Then, oxygen was introduced into the chamber to react with Si elements of the Si film to form SiO2. Thus, the third layer 23 shown in
The process for forming the fourth layer 24 was repeated again to form the second layer 22 on the third layer 23, and the process for forming the third layer 23 was repeated again to form the first layer 21 on the second layer 22. Thus, the anti-reflection film 2 was formed on the substrate 1.
Next, the anti-reflection film 2 was cleaned with argon plasma. After cleaning, C3F8 gas (500 sccm) was introduced into the same chamber of the PVD equipment, followed by turning on the plasma generator. The C3F8 gas was decomposed by microwave (1500 W). The bias RF (1500 W) was also applied. The surface of the first layer 21 of the anti-reflection film 2 was treated with the C3F8 plasma at 120 Pa for 60 seconds. Thus, the hydrophobic layer 3 was formed on the anti-reflection film 2.
The contact angles of the anti-reflection film 2 and the hydrophobic layer 3 were measured by using the contact angle meter, and the measurement results are listed in the following Table 1. In Table 1, “Before” means the film before the fluoride treatment (i.e., the anti-reflection film 2), “After” means the film after the fluoride treatment (i.e., the hydrophobic layer 3), “Pos 1” to “Pos 3” means the first position to the third position, “Avg” means the average contact angle, “Max” means the maximum contact angle, and “Min” means the minimum contact angle.
According to the results shown in Table 1, the hydrophobic layer 3 has the contact angle over than 100 degrees, but the anti-reflection film 2 has the contact angle less than 20 degrees. Thus, the hydrophilic anti-reflection film 2 can be converted into the hydrophobic layer 3 by fluoride treatment.
Although the present disclosure has been explained in relation to its embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the disclosure as hereinafter claimed.
This application claims the benefit of filing date of U.S. Provisional Application Ser. No. 63/117,095 filed Nov. 23, 2020 under 35 USC § 119(e)(1).
| Number | Date | Country | |
|---|---|---|---|
| 63117095 | Nov 2020 | US |
