Coated Substrate

The present disclosure relates to a coated substrate.

Patent Literatures 1 to 4 disclose coated substrates having metal oxide films. In Patent Literatures 1 to 4, a wet film-formation method is employed. Meanwhile, in some cases, a dry film-formation method (dry process) has been employed so as to perform thickness control in accordance with complex substrate shapes.

In consideration of application to various fields and mass production, conventional coated substrates are not necessarily satisfactory, and development of a novel coated substrate has been desired.

The present disclosure was made in view of the above-described circumstances, and an object is to provide a novel coated substrate which can be applied to various fields and can be mass produced. The present disclosure can be realized as the following modes.

[1] A coated substrate in which a substrate is coated with a film, wherein

[2] The coated substrate recited in [1], wherein a portion of the substrate where the film is formed is electrically conductive.

[3] The coated substrate recited in [1] or [2], wherein the x-ray photoelectron spectroscopic measurement of the film shows that the percent element composition of C (carbon) is 0.1 atm % or greater and less than 20 atm %.

[4] The coated substrate recited in [1] or [2], wherein the film is amorphous.

[5] The coated substrate recited in [1] or [2], wherein the condition (1) is such that the maximum thickness of the film formed on the edge region is greater than the thickness of the film formed on the inner region by 10% or more of the thickness of the film formed on the inner region.

[6] The coated substrate recited in [1] or [2], wherein the condition (2) is such that the maximum thickness of the film formed on the convex portion present region is greater than the thickness of the film formed on the convex portion absent region by 10% or more of the thickness of the film formed on the convex portion absent region.

[7] The coated substrate recited in [1] or [2], wherein the condition (1) is such that the thickness of the film decreases toward the inner region from a position where the film formed on the edge region has the maximum thickness.

[8] The coated substrate recited in [1] or [2], wherein the condition (2) is such that the thickness of the film decreases toward the convex portion absent region from a position where the film formed on the convex portion present region has the maximum thickness.

[9] The coated substrate recited in [1] or [2], wherein the metal element is at least one or more metal elements selected from the group consisting of Al (aluminum), Ti (titanium), Mo (molybdenum), Cr (chromium), Mn (manganese), Fe (iron), Co (cobalt), Ni (nickel), Zr (zirconium), V (vanadium), W (tungsten), Ta (tantalum), Nb (niobium), and Sn (tin).

According to the present disclosure, there is provided a novel coated substrate which can be applied to various fields and can be mass produced.

The present disclosure will now be described in detail. Notably, in the present specification, in a description in which “-” is used for a numerical range, the numerical range contains its upper and lower limit values, unless otherwise specifically noted. For example, a description of “10-20” should be read to contain both “10” (lower limit value) and “20” (upper limit value). Namely, “10-20” has the same meaning as “10 or greater and 20 or less.” Also, in the present specification, the upper and lower limit values of various numerical ranges may be combined freely.

A coated substrateincludes a substratecoated with a film. The thickness T of the filmis 1 nm or greater and less than 800 nm. X-ray photoelectron spectroscopic measurement of the filmshows that the total percent element composition of a metal element and O (oxygen) is 70 atm % or greater. The relative density of the filmis 90% or greater. The coated substratesatisfies at least one of the following conditions (1) and (2). The functionality of the coated substrateis enhanced as a result of satisfaction of at least one of the conditions (1) and (2).

Condition (1): the maximum thickness Tof the filmformed on an edge region Sof a surface S of the substrateis greater than the thickness Tof the filmformed on an inner region Sof the surface S located inward of the edge region S.

Condition (2): the maximum thickness Tof the filmformed on a convex portion present region Sof the surface S of the substrateis greater than the thickness Tof the filmformed on a convex portion absent region Sof the surface S.

shows a schematic view of a cross section of one example of the coated substrate. Althoughshows an example in which the filmis formed on one side of the substrate, the filmmay be formed on opposite sides of the substrate.

shows a schematic view of a cross section of another example of the coated substrate. Althoughshows an example in which the filmis formed on one side of the substrate, the filmmay be formed on opposite sides of the substrate.

No particular limitation is imposed on the substrate. In order to enhance adhesion of the filmto the substrate, at least a portion (region) of the substrate, which portion is to be coated with the film, is preferably formed of a material which is electrically conductive and can function as a negative electrode(cathode). In the case where the portion (region) of the substrate, which portion is to be coated with the film, is electrically conductive and can function as the negative electrode(cathode), the filmcan be easily formed on that portion by a manufacturing method described below.

A surface portion of the substratemay be formed of a material which is electrically conductive and can function as the negative electrode. The entire substratemay be formed of a material which can function as the negative electrode. Examples of preferred materials which can serve as the negative electrodeinclude an iron-based alloy and carbon. An example of preferred iron-based alloys is one or more types of alloys selected from Fe—Ni—Cr alloy (stainless steel), Fe—Ni alloy (permalloy), Fe—Si alloy (silicon iron), Fe—Si—Al alloy (Sendust), Fe—Ni—Mo (supermalloy), Fe—Co alloy (permendur), and Fe—C—B alloy (amorphous).

The thickness T of the filmis the shortest distance from a point on the surface of the filmto the surface S of the substrate. From the viewpoint of enabling the filmto exhibit a function corresponding to the material of the film, the thickness T of the filmis 1 nm or greater, preferably 10 nm or greater, more preferably 50 nm or greater. Meanwhile, from the viewpoint of enabling the filmto endure stresses generated therein and securing adhesion to the substrate, the thickness T of the filmis less than 800 nm, preferably 500 nm or less, more preferably 200 nm or less. From theses viewpoints, the thickness T of the filmis 1 nm or greater and less than 800 nm, preferably 10 nm or greater and 500 nm or less, more preferably 50 nm or greater and 200 nm or less. Notably, in the case where the thickness T of the filmis not uniform, the filmsatisfies the requirement regarding the thickness T when the thickness T of at least a portion of the filmfalls within the above-described range. The thickness of the filmcan be obtained through observation under an FIB-SEM.

The condition (1) is such that the maximum thickness Tof the filmformed on the edge region Sof the surface S of the substrateis greater than the thickness Tof the filmformed on the inner region Sof the surface S located inward of the edge region S. The maximum thickness Tof the filmformed on the edge region Sis the maximum value of the thickness Tof the filmformed on the edge region S.

No particular limitation is imposed on the edge region Sso long as it is an edge portion of the surface S. The edge region Sis, for example, a region which is located, in a cross sectional view, within a circular region whose center is located an end portion SE of the surface S of the substrateand whose radius is 5 mm. In the example of, the edge region Sis a region surrounded by a dash-dot line. In the example of, the maximum thickness Tis the thickness Tat the end portion SE.

No particular limitation is imposed on the maximum thickness T. The maximum thickness Tis, for example, preferably 10 nm or greater and 1000 nm or less, more preferably 50 nm or greater and 800 nm or less, further preferably 100 nm or greater and 500 nm or less.

No particular limitation is imposed on the thickness Tso long as the thickness Tis smaller than the maximum thickness T. The thickness Tis, for example, preferably 1 nm or greater and 800 nm or less, more preferably 10 nm or greater and 500 nm or less, further preferably 50 nm or greater and 200 nm or less.

In the condition (1), from the viewpoint of enhancing the functionality of the coated substrate, the maximum thickness Tof the filmformed on the edge region Sis preferably greater than the thickness Tof the filmformed on the inner region Sby 10% or more of the thickness T, more preferably greater than the thickness Tby 20% or more of the thickness T, and further preferably greater than the thickness Tby 30% or more of the thickness T. In the case where the thickness Tis not uniform, if the maximum thickness Tis greater than the thickness Tin at least a portion of the inner region Sby a certain percentage or more of the thickness T, the above-described relation is satisfied. Although no particular limitation is imposed of the upper limit value of the ratio of the maximum thickness Tto the thickness T, it is preferred that, in condition (1), the maximum thickness Tis equal to or less than 400% of the thickness T.

In condition (1), it is preferred that the thickness T of the filmdecreases toward the inner region Sfrom a position where the filmformed on the edge region Shas the maximum thickness T. Notably, irregularities whose sizes are equal to or less than 10% of the maximum thickness Tare not taken into consideration. By virtue of this configuration, the influence of residual stresses occurring at the interface of the substratecan be mitigated in a wide region.

Notably, determination as to whether or not the condition (1) regarding the thickness T of the filmis satisfied is made by observing, under an FIB-SEM, a cross section of the coated substratewhich extends perpendicularly to the surface S of the substrate.

The condition (2) is such that the maximum thickness Tof the filmformed on the convex portion present region Sof the surface S of the substrateis greater than the thickness Tof the filmformed on the convex portion absent region Sof the surface S.

The maximum thickness Tof the filmformed on the convex portion present region Sis the maximum value of the thickness Tof the filmformed on the convex portion present region S. No particular limitation is imposed on the shape, size, number of a convex portion(s). Notably, in the case where a plurality of convex portionsare present, the condition (2) regarding the thickness T of the filmis satisfied if the condition (2) is satisfied in a combination of the filmformed on the convex portion present region Sassociated with one convex portionand the filmformed on the convex portion absent region Slocated adjacent thereto. The convex portionmay have, for example, a mount-like shape, a protruding shape, a needle-like shape, or a columnar shape. Although no particular limitation is imposed on the maximum height h of the convex portion, the maximum height h is, for example, preferably 100 nm or greater and 10 mm or less, more preferably 500 nm or greater and 5 mm or less, further preferably 1000 nm or greater and 2 mm or less. The maximum height h of the convex portionmeans the height from the surface S of the substratein the convex portion absent region S, which surface severs as a reference. Although no particular limitation is imposed on the occupation area of the convex portionas viewed orthogonally from the upper side of the substrate, the occupation area is, for example, preferably 10 μm2 or greater and 100 mmor less, more preferably 100 μmor greater and 10 mmor less, further preferably 500 μmor greater and 1 mmor less.

No particular limitation is imposed on the maximum thickness T. The maximum thickness Tis, for example, preferably 10 nm or greater and 1000 nm or less, more preferably 50 nm or greater and 800 nm or less, further preferably 100 nm or greater and 500 nm or less.

No particular limitation is imposed on the thickness Tso long as the thickness Tis smaller than the maximum thickness T. The thickness Tis, for example, preferably 1 nm or greater and 800 nm or less, more preferably 10 nm or greater and 500 nm or less, further preferably 50 nm or greater and 200 nm or less.

In the condition (2), from the viewpoint of enhancing the functionality of the coated substrate, the maximum thickness Tof the filmformed on the convex portion present region Sis preferably greater than the thickness Tof the filmformed on the convex portion absent region Sby 10% or more of the thickness T, more preferably greater than the thickness Tby 20% or more of the thickness T, and further preferably greater than the thickness Tby 30% or more of the thickness T. In the case where the thickness Tis not uniform, if the maximum thickness Tis greater than the thickness Tin at least a portion of the convex portion absent region Sby a certain percentage or more of the thickness T, the above-described relation is satisfied. Although no particular limitation is imposed of the upper limit value of the ratio of the maximum thickness Tto the thickness T, it is preferred that, in condition (2), the maximum thickness Tis equal to or less than 400% of the thickness T.

In condition (2), it is preferred that the thickness T of the filmdecreases toward the convex portion absent region Sfrom a position where the filmformed on the convex portion present region Shas the maximum thickness T. Notably, irregularities whose sizes are equal to or less than 10% of the maximum thickness Tare not taken into consideration. By virtue of this configuration, the influence of residual stresses occurring at the interface of the substratecan be mitigated in a wide region.

Notably, determination as to whether or not the condition (2) regarding the thickness T of the filmis satisfied is made by observing, under an FIB-SEM, a cross section of the coated substratewhich extends perpendicularly to the surface S of the substrate.

From the viewpoint of suppressing growth of crystal grains in the filmand stabilizing the properties of the film, the percent element composition of C (carbon) determined through measurement by x-ray photoelectron spectroscopy (XPS method) is 0.1 atm % or greater, preferably 0.5 atm % or greater, more preferably 1 atm % or greater. Meanwhile, from the viewpoint of enabling the filmto sufficiently function as an inorganic film, the percent element composition of C (carbon) is less than 20 atm %, preferably 15 atm % or less, more preferably 10 atm % or less. From these viewpoints, the percent element composition of C (carbon) is 0.1 atm % or greater and less than 20 atm %, preferably 0.5 atm % or greater and 15 atm % or less, more preferably 1 atm % or greater and 10 atm % or less. Notably, in the case where the composition of the filmis not uniform, the filmsatisfies the requirement regarding the percent element composition of C (carbon) when the composition of at least a portion of the filmfalls within the above-described range.

The composition analysis by the x-ray photoelectron spectroscopy can be performed by using an x-ray photoelectron spectrometer. The measurement can be performed by scanning a cross section under the following measurement conditions: K-alpha rays of aluminum being used as an x-ray source, the beam diameter being set to 100 μm, and the x-ray incident angle in relation to a surface to be analyzed being set to 45°.

From the viewpoint of enabling the filmto sufficiently function as an inorganic film, the total percent element composition of the metal element and O (oxygen) of the filmdetermined through measurement by the x-ray photoelectron spectroscopy (XPS method) is 70 atm % or greater, preferably 80 atm % or greater, more preferably 90 atm % or greater. Notably, the upper limit of the total percent element composition of the metal element and O (oxygen) is a value obtained by subtracting the percent element composition (atm %) of C (carbon) from 100 atm %. In the case where the composition of the filmis not uniform, the filmsatisfies the requirement regarding the total percent element composition of the metal element and O (oxygen) when the composition of at least a portion of the filmfalls within the above-described range.

From the viewpoint of enabling the filmto sufficiently exhibit the function of the film, the relative density of the filmis 90% or greater, preferably 95% or greater, more preferably 98% or greater. The relative density of the filmmay be 100%.

The relative density of the filmis obtained by the following method. A TEM image of a cross section of the filmobtained by cutting the filmin the film-thickness direction is obtained. The area of pores in a field of view of 300 nm (vertical dimension)×1000 nm (horizontal dimension) is measured. The relative density (%) is obtained in accordance with the following expression (1). The average of the relative densities of 10 fields of view is the relative density of the film. Notably, in the case where the thickness of the filmis smaller than the vertical size of 300 nm, measurement is performed in fields of view determined in accordance with the thickness of the film.

(In the expression, S1 is the area (nm) of the field of view of 300 nm (vertical dimension)×1000 nm (horizontal dimension), and S2 is the total area (nm) of pores in the field of view of 300 nm (vertical dimension)×1000 nm (horizontal dimension))

It is preferred that the filmis amorphous. The fact that the filmis amorphous can be confirmed by using a TEM image. When the filmis amorphous, it is expected that crystal grains do not come off and peculiar functions (such as smoothing the outermost surface by uniform film growth) are exhibited.

(2.8) Compound Having at Least One Type of Structure Selected from C—H Bond, C—O Bond, and C—O Bond

The filmpreferably contains a compound having at least one type of structure selected from C—H bond, C═O bond, and C—O bond. Since the compound having at least one type of structure selected from C—H bond, C═O bond, and C—O bond vaporizes at a lower temperature as compared with elemental C (carbon) and induces contraction of the film, it is supposed that the denseness of the filmincreases.

Also, since the compound having at least one type of structure selected from C—H bond, C—O bond, and C—O bond remains, it is supposed that the flexibility of the filmis maintained, and the adhesion of the filmto the substrateis enhanced.

The percent element composition of the halogen element as determined through measurement of the filmby x-ray photoelectron spectroscopy is preferably 0.1 atm % or greater, more preferably 0.3 atm % or greater, further preferably 0.5 atm % or greater. The upper limit value of the percent element composition of the halogen element is 3 atm % or less.