METHODS OF MANUFACTURING GLASS SUBSTRATE STRUCTURE AND METALLIZED SUBSTRATE

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefits of priority under 35 U.S.C. § 119 of Korean Patent Application Serial No.: 10-2021-0122763, filed on September 14, 2021 , the content of which is relied upon and incorporated herein by reference in its entirety.

BACKGROUND

1. Field

[0002] The disclosure relates to a method of manufacturing a glass substrate structure and a method of manufacturing a metallized substrate, and more particularly, to a method of manufacturing a glass substrate structure and a method of manufacturing a metallized substrate, which may enable inexpensive manufacturing and provide excellent interlayer adhesion.

2. Description of the Related Art

[0003] Conventional printed circuit boards have limitations in thermal stability and mechanical stability, and thus, there is a problem of warpage and deterioration of pattern precision. Compared with conventional printed circuit boards, glass substrates significantly alleviate the problem of warpage, but are expensive because electroless plating using expensive catalysts is required. Furthermore, a method of manufacturing a glass substrate structure according to the related art requires improvement because there is a problem in interlayer adhesion due to voids in a metal wiring layer.

SUMMARY

[0004] Provided is a method of manufacturing a glass substrate structure such as a glass circuit board, which may enable inexpensive manufacturing and provide excellent interlayer adhesion.

[0005] Provided is a method of manufacturing a metallized substrate, which may enable inexpensive manufacturing and provide excellent interlayer adhesion.

[0006] Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.

1

RECTIFIED SHEET (RULE 91) ISA/KR [0007] According to an aspect of the disclosure, a method of manufacturing a glass substrate structure includes forming an adhesion promoter layer on a surface of a glass substrate, forming a seed layer of a first metal on a surface of the adhesion promoter layer, and forming a bulk layer of a second metal through an autocatalytic reaction on the seed layer.

[0008] In some embodiments, the method may further include, after the forming of the seed layer and before the forming of the bulk layer, performing an acid treatment on a surface of the seed layer. In some embodiments, the method may further include, after the performing of the acid treatment and before the forming of the bulk layer, performing alkali cleaning on the surface of the seed layer.

[0009] In some embodiments, each of the adhesion promoter layer and the seed layer may be formed by physical vapor deposition (PVD). In some embodiments, the forming of the bulk layer may include applying a bulk mixture to the seed layer, the bulk mixture including metal ions of the second metal of about 0.5 g/l to about 8 g/l, a reducing agent of about 0.01 M to about 1.0 M, and a complexing agent of about 0.05 M to about 1.0 M. In some embodiments, the bulk mixture may further include a stabilizer of about 10 weight ppm to about 1000 weight ppm. In some embodiments, the forming of the bulk layer may be performed at a temperature of about 30°C to about 60°C. In some embodiments, the bulk mixture may further include a pH adjuster to adjust a pH to be about 9 to about 11 .

[0010] In some embodiments, the seed layer may include one or more selected from the group consisting of copper (Cu), tin (Sn), nickel (Ni), ion (Fe), aluminum (Al), zinc (Zn), sodium (Na), calcium (Ca), and magnesium (Mg).

[0011] In some embodiments, a thickness of the bulk layer may be about 2.0 pm to about 10 pm.

[0012] According to another aspect of the disclosure, a method of manufacturing a metallized substrate includes forming an adhesion promoter layer on an entire upper surface of a glass substrate, forming a seed layer of a first metal on a surface of the adhesion promoter layer, forming a mask layer having a mask pattern on the seed layer, etching the seed layer to form a seed pattern, applying a bulk mixture to the seed layer to form a bulk layer of a second metal on the seed layer, the bulk mixture including: metal ions of the second metal of about 0.5 g/l to about 8 g/l, a reducing agent of about 0.01 M to about 1.0 M, and a complexing agent of about 0.05 M to about 1.0 M, and removing the mask layer. [0013] In some embodiments, the removing of the mask layer may be performed after the etching of the seed layer and before the applying of the bulk mixture. In some embodiments, a surface of the bulk layer may include a curved surface extending along the seed pattern.

[0014] In some embodiments, the applying of the bulk mixture may be performed after the forming of the seed layer and before the etching of the seed layer, and the forming of the mask layer on the seed layer may include forming the mask layer above the seed layer with the bulk layer therebetween. In some embodiments, the removing of the mask layer may be performed after the etching of the seed layer.

[0015] In some embodiments, the etching of the seed layer may include etching the bulk layer using the mask layer as an etching mask, and forming a seed pattern using the etched bulk layer as an etching mask.

[0016] In some embodiments, the method may further include, before the applying of the bulk mixture, performing an acid treatment on a surface of the seed layer. In some embodiments, the method may further include, after the performing of the acid treatment and before the applying of the bulk mixture, performing alkali cleaning on the surface of the seed layer.

[0017] In some embodiments, the average size of crystal grains of the bulk layer may be greater than the average size of crystal grains of the seed layer.

[0018] According to another aspect of the disclosure, a method of manufacturing a glass substrate structure includes forming an adhesion promoter layer on a surface of a glass substrate by sputtering to a thickness of about 30 nm to about 150 nm, forming a seed layer of a first metal on a surface of the adhesion promoter layer by sputtering to a thickness of about 300 nm to about 700 nm, performing an acid treatment on a surface of the seed layer with an inorganic acid aqueous solution, performing alkali cleaning on the surface of the seed layer, and forming a bulk layer of a second metal on the seed layer through an autocatalytic reaction to a thickness of about 2.0 pm to about 10 pm. The forming of the bulk layer includes applying a bulk mixture to the seed layer, the bulk mixture including metal ions of the second metal of about 0.5 g/l to about 8 g/l, a reducing agent of about 0.01 M to about 1.0 M, and a complexing agent of about 0.05 M to about 1.0 M, and each of the first metal and the second metal independently includes one or more selected from the group consisting of copper (Cu), tin (Sn), nickel (Ni), ion (Fe), aluminum (Al), zinc (Zn), sodium (Na), calcium (Ca), and magnesium (Mg), and the first metal and the second metal are selected such that a standard reduction potential of the first metal is less than or equal to a standard reduction potential of the second metal.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0020] FIG. 1 is a flowchart of a method of manufacturing a glass substrate structure, according to an embodiment of the disclosure;

[0021] FIGS. 2A to 2E are side cross-sectional views of the method of manufacturing a glass substrate structure, according to the embodiment of FIG. 1 ;

[0022] FIGS. 3A to 3D are side cross-sectional views of a method of manufacturing a metallized substrate, according to an embodiment of the disclosure;

[0023] FIGS. 4A to 4D are side cross-sectional views of a method of manufacturing a metallized substrate, according to another embodiment of the disclosure;

[0024] FIGS. 5A to 5D are side cross-sectional views of a method of manufacturing a metallized substrate, according to another embodiment of the disclosure;

[0025] FIG. 6 is a scanning electron microscope (SEM) image of an enlarged crosssection of a stack structure manufactured by a method of manufacturing a metallized substrate, according to an embodiment of the disclosure;

[0026] FIG. 7 is a SEM image of an enlarged cross-section of a stack structure manufactured by a method of manufacturing a metallized substrate, according to another embodiment of the disclosure;

[0027] FIG. 8 is a SEM image of enlarged cross-sections of a seed layer and a bulk layer in a stack structure manufactured by a method of manufacturing a metallized substrate, according to another embodiment of the disclosure;

[0028] FIG. 9 is a SEM image of a stack structure manufactured by the same method as that according to the embodiment of FIG. 8, except that a pre-dip process is not performed; and

[0029] FIGS. 10A and 10B are images of a surface of a bulk layer when the pre-dip process is performed and when the pre-dip process is not performed, respectively. DETAILED DESCRIPTION

[0030] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals referto like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Expressions such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

[0031] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the teachings of the disclosure.

[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," or "includes" and/or "including" when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or combinations thereof.

[0033] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present application, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. [0034] When it is possible to modify an embodiment, the order of processes may be different from the order in which the processes have been described. For instance, two processes described as being performed sequentially may be substantially performed simultaneously or in a reverse order.

[0035] In the drawings, transformation of the shapes may be expected according to, for example, manufacturing techniques and/or tolerance. Accordingly, embodiments should not be construed as being limited to specified shapes in the drawings but as including changes in the shapes occurring during, for example, manufacturing processes. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. In addition, the term "substrate" used herein may refer to a substrate itself or a stack structure that includes a substrate and a certain layer or film formed on a surface of the substrate. The expression "surface of the substrate" may refer to an exposed surface of the substrate itself or an outer surface of a certain layer or film formed on the substrate.

[0036] FIG. 1 is a flowchart of a method of manufacturing a glass substrate structure, according to an embodiment of the disclosure. FIGS. 2Ato 2E are side cross-sectional views of the method of manufacturing a glass substrate structure, according to the embodiment of FIG. 1.

[0037] Referring to FIGS. 1 and 2A, an adhesion promoter layer 120 is formed on a glass substrate 110 (S10).

[0038] The glass substrate 110 may include, for example, aluminosilicate, alkalialuminosilicate, borosilicate, alkali-borosilicate, aluminoborosilicate, alkali- alum inoborosilicate, soda-lime, or other suitable glass, but the disclosure is not limited thereto. Non-limiting examples of the glass substrate 110 may include, for example, EAGLE XG®, Lotus™, Willow®, Iris™, and Gorilla® glasses from Coming Incorporated. [0039] The glass substrate 110 may have a thickness of about 3 mm or less, for example, ranging from about 0.1 mm to about 2.5 mm, from about 0.3 mm to about 2 mm, from about 0.5 mm to about 1.5 mm, or from about 0.7 mm to about 1 mm, and including all ranges and subranges therebetween.

[0040] Some non-limiting glass compositions may include between about 50 mol% to about 90 mol% SiO2, between 0 mol% to about 20 mol% AI2O3, between 0 mol% to about 20 mol% B2O3, between 0 mol% to about 20 mol% P2O5, and between 0 mol% to about 25 mol% RxO, wherein R is any one or more of Li, Na, K, Rb, and Cs and x is 2, or R is Zn, Mg, Ca, Sr, or Ba and x is 1. In some embodiments, RxO - AI2O3 > 0; 0 < RxO - AI2O3 < 15; x = 2 and R2O - AI2O3 < 15; R2O - AI2O3 < 2; x=2 and R2O - AI2O3 - MgO > -15; 0 < (RxO - AI2O3) < 25, -11 < (R2O - AI2O3) < 11 , and -15 < (R2O - AI2O3 - MgO) < 11 ; and/or -1 < (R2O - AI2O3) < 2 and -6 < (R2O - AI2O3 - MgO) < 1. In some embodiments, the glass comprises less than 1 ppm each of Co, Ni, and Cr. In some embodiments, the concentration of Fe is less than about 50 ppm, less than about 20 ppm, or less than about 10 ppm. In other embodiments, Fe + 30Cr + 35Ni < about 60 ppm, Fe + 30Cr + 35Ni < about 40 ppm, Fe + 30Cr + 35Ni < about 20 ppm, or Fe + 30Cr + 35Ni < about 10 ppm. In other embodiments, the glass may comprise between about 60 mol % to about 80 mol% SiO2, between about 0.1 mol% to about 15 mol% AI2O3, between 0 mol% to about 12 mol% B2O3, and between about 0.1 mol% to about 15 mol% RxO and about 0.1 mol% to about 15 mol% RxO, wherein R is any one or more of Li, Na, K, Rb, and Cs and x is 2, or R is Zn, Mg, Ca, Sr, or Ba and x is 1.

[0041] In other embodiments, the glass composition may comprise between about 65.79 mol % to about 78.17 mol% SiO2, between about 2.94 mol% to about 12.12 mol% AI2O3, between about 0 mol% to about 11.16 mol% B2O3, between about 0 mol% to about 2.06 mol% U2O, between about 3.52 mol% to about 13.25 mol% Na2O, between about 0 mol% to about 4.83 mol% K2O, between about 0 mol% to about 3.01 mol% ZnO, between about 0 mol% to about 8.72 mol% MgO, between about 0 mol% to about 4.24 mol% CaO, between about 0 mol% to about 6.17 mol% SrO, between about 0 mol% to about 4.3 mol% BaO, and between about 0.07 mol% to about 0.11 mol% SnO2.

[0042] In additional embodiments, the glass substrate 110 can comprise glass having an RXO/AI2O3 ratio between 0.95 and 3.23, wherein R is any one or more of Li, Na, K, Rb, and Cs and x is 2. In further embodiments, the glass may comprise an RxO/ALOs ratio between 1.18 and 5.68, wherein R is any one or more of Li, Na, K, Rb, and Cs and x is 2, or R is Zn, Mg, Ca, Sr or Ba and x is 1. In yet further embodiments, the glass may comprise an RxO - AI2O3 - MgO between -4.25 and 4.0, wherein R is any one or more of Li, Na, K, Rb, Cs and x is 2. In still further embodiments, the glass may comprise between about 66 mol % to about 78 mol% SiO2, between about 4 mol% to about 11 mol% AI2O3, between about 4 mol% to about 11 mol% B2O3, between about 0 mol% to about 2 mol% U2O, between about 4 mol% to about 12 mol% Na2O, between about 0 mol% to about 2 mol% K2O, between about 0 mol% to about 2 mol% ZnO, between about 0 mol% to about 5 mol% MgO, between about 0 mol% to about 2 mol% CaO, between about 0 mol% to about 5 mol% SrO, between about 0 mol% to about 2 mol% BaO, and between about 0 mol% to about 2 mol% SnO2.

[0043] In additional embodiments, the glass substrate 110 may comprise a glass material including between about 72 mol % to about 80 mol% SiC>2, between about 3 mol% to about 7 mol% AI2O3, between about 0 mol% to about 2 mol% B2O3, between about 0 mol% to about 2 mol% U2O, between about 6 mol% to about 15 mol% Na2O, between about 0 mol% to about 2 mol% K2O, between about 0 mol% to about 2 mol% ZnO, between about 2 mol% to about 10 mol% MgO, between about 0 mol% to about 2 mol% CaO, between about 0 mol% to about 2 mol% SrO, between about 0 mol% to about 2 mol% BaO, and between about 0 mol% to about 2 mol% SnO2. In certain embodiments, the glass may comprise between about 60 mol % to about 80 mol% SiO2, between about 0 mol% to about 15 mol% AI2O3, between about 0 mol% to about 15 mol% B2O3, and between about 2 mol% to about 50 mol% RxO, wherein R is any one or more of Li, Na, K, Rb, and Cs and x is 2, or R is Zn, Mg, Ca, Sr or Ba and x is 1 , and wherein Fe + 30Cr + 35Ni < about 60 ppm.

[0044] The adhesion promoter layer 120 is provided to increase adhesion between the glass substrate 110 and a seed layer 130 to be formed later.

[0045] The adhesion promoter layer 120 may include, for example, a metal such as titanium (Ti), chromium (Cr), tungsten (W), molybdenum (Mo), tin (Sn), iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), gold (Au), silver (Ag), platinum (Pt), tantalum (Ta), hafnium (Hf), and the like, or an oxide of the metals.

[0046] The adhesion promoter layer 120 may be formed by physical vapor deposition (PVD). For example, the adhesion promoter layer 120 may be formed by a method such as sputtering, evaporation, and the like. In some embodiments, the adhesion promoter layer 120 may be formed by sputtering.

[0047] The thickness of the adhesion promoter layer 120 may range from about 10 nm to about 200 nm. In some embodiments, the thickness of the adhesion promoter layer 120 may range from about 10 nm to about 200 nm, from about 20 nm to about 190 nm, from about 30 nm to about 180 nm, from about 40 nm to about 170 nm, from about 50 nm to about 160 nm, from about 60 nm to about 150 nm, from about 70 nm to about 140 nm, from about 80 nm to about 130 nm, or from about 90 nm to about 120 nm, or a certain range between the above values.

[0048] When the thickness of the adhesion promoter layer 120 is too thick, it may be economically disadvantageous because an effect according to the formation of the adhesion promoter layer 120 is saturated. When the thickness of the adhesion promoter layer 120 is too thin, the adhesion promoter layer 120 may be formed insufficiently in some areas, and thus an effect of adhesion promotion may be deteriorated.

[0049] Referring to FIGS. 1 and 2B, the seed layer 130 is formed on the adhesion promoter layer 120 (S20). The seed layer 130 may act as a start layer for forming a bulk layer to be formed later.

[0050] The seed layer 130 may include a metal different from the metal of the adhesion promoter layer 120, and may be, for example, one or more selected from the group consisting of copper (Cu), tin (Sn), nickel (Ni), iron (Fe), aluminum (Al), zinc (Zn), sodium (Na), calcium (Ca), and magnesium (Mg).

[0051] The seed layer 130 may be formed by PVD. For example, the seed layer 130 may be formed by a method such as sputtering, evaporation, and the like. In some embodiments, the seed layer 130 may be formed by sputtering.

[0052] The thickness of the seed layer 130 may range from about 200 nm to about 1000 nm. In some embodiments, the thickness of the seed layer 130 may range from about 200 nm to about 1000 nm , from about 240 nm to about 900 nm , from about 280 nm to about 800 nm, from about 300 nm to about 700 nm, from about 320 nm to about 650 nm , from about 340 nm to about 600 nm , and from about 350 nm to about 550 nm , or a certain range between the above values.

[0053] Referring to FIGS. 1 and 2C, an acid treatment may be performed on an exposed surface of the seed layer 130 (S30).

[0054] The acid treatment is performed to remove an oxide existing on a surface of the seed layer 130 and may be performed by organic acid or inorganic acid. In some embodiments, the acid treatment may be performed by contacting a solution 160a of the organic acid or inorganic acid with the surface of the seed layer 130.

[0055] An acid treatment time may range from about 10 seconds to about 10 minutes, from about 20 seconds to about 8 minutes, from about 30 seconds to about 6 minutes, from about 40 seconds to about 5 minutes, from about 50 seconds to about 4 minutes, from about 1 minute to about 3 minutes, or may be in a certain range between the above values. When the acid treatment time is too long, an effect according to the acid treatment may be saturated and throughput may be reduced to be uneconomical. When the acid treatment time is too short, the oxide removal may be performed insufficiently. [0056] The acid treatment may be generally performed at room temperature. For example, the acid treatment may be performed at a temperature ranging from about 10°C to about 45°C, from about 15°C to about 40°C, from about 20°C to about 37°C, from about 25°C to about 35°C, or in a certain range between the above values.

[0057] The inorganic acid may include, for example, sulfuric acid (H2SO4), hydrochloric acid (HCI), nitric acid (HNOs), phosphoric acid (H3PO4), sulfamic acid (SO3HNH2), perchloric acid (HCIO4), chromium acid (H2crO4), sulfurous acid (H2SO3), nitrous acid (HNO2), or a mixture thereof, but the disclosure is not limited thereto.

[0058] The organic acid may include, for example, formic acid, acetic acid, trifluoro acetic acid, diacetic acid, imino diacetic acid, oxalic acid, citric acid, ascorbic acid, propionic acid, sorbic acid, succinic acid, fumaric acid, oleic acid, glycolic acid, stearic acid, lactic acid, pyruvic acid, malonic acid, glutaric acid, malic acid, mandelic acid, tartaric acid, palmitic acid, pamoic acid, maleic acid, hydroxy maleic acid, glutamic acid, benzoic acid, acetoxybenzoic acid, salicylic acid, phenyl acetic acid, cinnamic acid, methane sulfonic acid, ethane sulfonic acid, benzene sulfonic acid, toluene sulfonic acid, aniline sulfonic acid, naphthalene sulfonic acid, naphthalene disulfonic acid, or a mixture thereof, but the disclosure is not limited thereto.

[0059] The acid treatment may be performed under a pH of about 0 to 3. In some embodiments, the acid treatment may be performed under a pH of about 0 to 2.5, from about 0 to 2.3, from about 0 to 2.0, and about 0 to 1 .7.

[0060] To adjust a pH for the acid treatment, an addition amount of the inorganic acid or organic acid may be adjusted. For example, the concentration of the inorganic acid or organic acid may range from about 0.5 wt% to about 20 wt%, from about 1 wt% to about 15 wt%, from about 2 wt% to about 10 wt%, or may be in a certain range between the above values.

[0061] When the concentration of the inorganic acid or organic acid is too high or a pH thereof is too low, the seed layer 130 may be damaged. When the concentration of the inorganic acid or organic acid is too low or a pH thereof is too high, the oxide removal may be performed insufficiently.

[0062] Then, the surface of the seed layer 130 may be rinsed to remove the solution of the inorganic acid or organic acid remaining on the surface of the seed layer 130. The rinse may be performed using, for example, water such as deionized water. [0063] Referring to FIGS. 1 and 2D, a pre-dip process may be performed on an exposed surface of the seed layer 130 (S40).

[0064] The pre-dip process is performed to remove an organic material remaining on the surface of the seed layer 130 and may be performed using an alkali solution 160b. In some embodiments, the pre-dip process may be performed by contacting the alkali solution 160b with the surface of the seed layer 130.

[0065] The pre-dip process may be performed for a period ranging from about 10 seconds to about 10 m inutes, from about 20 seconds to about 8 m inutes, from about 30 seconds to about 6 m inutes, from about 40 seconds to about 5 m inutes, from about 50 seconds to about 4 minutes, from about 1 minute to about 3 minutes, or in a certain range between the above values. When a pre-dip process time is too long, an effect according to the pre-dip process may be saturated and throughput may be reduced to be uneconomical. When the pre-dip process time is too short, the removal of the organic material may be performed insufficiently.

[0066] The pre-dip process may be generally performed at room temperature. For example, the pre-dip process may be performed at a temperature ranging from about 10°C to about 45°C, from about 15°C to about 40°C, from about 20°C to about 37°C, from about 25°C to about 35°C, or in a certain range between the above values.

[0067] The alkali solution may include, for example, a NaOH aqueous solution, a KOH aqueous solution, a NH4OH aqueous solution, an Mg(OH)2 aqueous solution, a Ca(OH)2 aqueous solution, a Ba(OH)2 aqueous solution, an AI(OH)s aqueous solution, or a mixture thereof, but the disclosure is not limited thereto.

[0068] The pre-dip process may be performed under a pH of about 9 to about 14. In some embodiments, the pre-dip process may be performed under a pH ranging from about 9.3 to about 13.7, from about 9.6 to about 13.4, from about 10 to about 13, from about 10.3 to about 12.7, from about 10.6 to about 12.4, from about 11 to about 12, or in a certain range between the above values.

[0069] To adjust a pH for the pre-dip process, the concentration of the alkali solution may range from about 0.1 wt% to about 2.0 wt%, from about 0.2 wt% to about 1.8 wt%, from about 0.3 wt% to about 1.6 wt%, from about 0.4 wt% to about 1.4 wt%, from about 0.5 wt% to about 1 .2 wt%, from about 0.6 wt% to about 1.0 wt%, or may be in a certain range between the above values. [0070] When the concentration of the alkali solution is too high, the seed layer 130 may be damaged. When the concentration of the alkali solution is too low, an effect of the removal of the organic material may be insufficient, and thus adhesion of a bulk layer 140 to be formed later may be deteriorated.

[0071] After the pre-dip process is completed, the surface of the seed layer 130 may not be rinsed.

[0072] Referring to FIGS. 1 and 2E, the bulk layer 140 is formed on the seed layer 130 (S50). In some embodiments, the bulk layer 140 may include the same metal as the seed layer 130. In some embodiments, the bulk layer 140 may include a metal different from the seed layer 130.

[0073] In some embodiments, the bulk layer 140 may be formed by electroless plating through autocatalytic reaction using the seed layer 130. The autocatalytic reaction may be performed by a reaction formula below using a reducing agent.

[0074] M ^z+ (aq) + X ^z - (aq) M° (s) + Z

[0075] In the reaction formula, M denotes a metal forming the bulk layer 140, X ^z - denotes a reducing agent, and Z denotes an oxidized reaction by-product. The reaction by-product, that is, Z, may be a liquid, a solid, or a gas.

[0076] The metal forming the bulk layer 140 may be the same as or different from the metal forming the seed layer 130. The metal forming the bulk layer 140, that is, M, may include, for example, one or more selected from the group consisting of Cu, Sn, Ni, Fe, Al, Zn, Na, Ca, and Mg. However, the metals forming the seed layer 130 and the bulk layer 140 may be selected such that the standard reduction potential of the metal forming the seed layer 130 is lower than or equal to the standard reduction potential of the metal forming the bulk layer 140.

[0077] In some embodiments, the metal forming the seed layer 130 and the metal forming the bulk layer 140 may be different from each other. In some embodiments, the metal forming the seed layer 130 and the metal forming the bulk layer 140 may be the same metal. Even when the metal forming the seed layer 130 and the metal forming the bulk layer 140 are the same, as the methods of forming the seed layer 130 and the bulk layer 140 are different from each other, an observable interface may exist between the seed layer 130 and the bulk layer 140. [0078] To form the bulk layer 140, the seed layer 130 may be immersed into a bulk mixture in an electroless plating bath. The bulk mixture may contain ions of a metal M forming the bulk layer 140 and a reducing agent.

[0079] To provide ions of the metal M, the bulk mixture may contain a salt of the metal M dissolved in a solvent. When the metal M is copper, examples of the salt of the metal M may include sulfate salt, chloride, nitride, acetate, formic acid salt of copper, their hydrates, and the like, but the disclosure is not limited thereto.

[0080] The ions of the metal M in the bulk mixture may have a concentration ranging, for exam pie, from about 0.01 M to about 0.5 M. In some embodiments, the ions of the metal M may have a concentration ranging from about 0.01 M to about 0.5 M, from about 0.015 M to about 0.4 M, from about 0.02 M to about 0.3 M, from about 0.025 M to about 0.2 M, from about 0.03 M to about 0.1 M, or in a certain range between the above values.

[0081] In some embodiments, the content of the metal M in the bulk mixture may range from about 0.5 g/l to about 20 g/l, from about 0.8 g/l to about 17 g/l, from about 1 g/l to about 15 g/l, from about 1.3 g/l to about 13 g/l, from about 1.5 g/l to about 10 g/l, from about 2 g/l to about 9 g/l, from about 2.2 g/l to about 8 g/l, from about 2.5 g/l to about

7 g/l, from about 2.7 g/l to about 6.5 g/l, from about 3 g/l to about 6 g/l, or may be in a certain range between the above values. In some embodiments, when the metal M is copper, ions of the metal M may be provided such that the concentration of copper in the bulk mixture ranges from about 0.5 g/l to about 10 g/l, from about 0.5 g/l to about

8 g/l, or from about 1 g/l to about 5 g/l.

[0082] The reducing agent may include, for example, sodium hypophosphite, formaldehyde, glyoxylic acid, hydrazine, dimethylamine borane, trimethylamine borane, 4-methylmorpholine borane, sodium borohydride, potassium borohydride, glucose, sucrose, cellulose, sorbitol, mannitol, ascorbic acid, formic acid, and the like, but the disclosure is not limited thereto.

[0083] The concentration of the reducing agent may range, for example, from about 0.01 M to about 1 M. In some embodiments, the reducing agent may have a concentration ranging, for example, from about 0.01 M to about 0.9 M, from about 0.02 M to about 0.8 M, from about 0.03 M to about 0.7 M, from about 0.04 M to about 0.6 M, from about 0.05 M to about 0.5 M, from about 0.06 M to about 0.4 M, from about 0.07 M to about 0.35 M, from about 0.08 M to about 0.3 M, from about 0.09 M to about 0.25 M, from about 0.1 M to about 0.2 M, or in a certain range between the above values. When the reducing agent includes two or more reducing agents, the sum of concentrations of all reducing agents is within the above range.

[0084] When the concentration of the reducing agent is too high, an effect obtainable from the reducing agent is saturated to be economically disadvantageous. When the concentration of the reducing agent is too low, a time for forming the bulk layer 140 is too long.

[0085] The bulk mixture may further include a complexing agent. The complexing agent may include, for example, sugar alcohols (e.g., xylitol, mannitol, and sorbitol), alkanol amines (e.g., triethanol amine), hydroxycarboxylic acids (e.g., lactic acid, citric acid, and tartaric acid), amino phosphonic acid and aminopolyphosphonic acid (e.g., aminotris (methylphosphonic acid)), aminocarboxylic acid (e.g., oligoamino monosuccinic acid, polyamino monosuccinic acid, oligoamino disuccinic acid, ethylenediamine-N,N'-disuccinic acid, polyamino disuccinic acid), aminopolycarboxylic acid (e.g., nitrilotriacetic acid, ethylenediamine tetraacetic acid (EDTA), N'-(2-hydroxyethyl)- Ethylenediamine-N,N,N'-triacetic acid (HEDTA), cyclohexanediamine tetraacetic acid, diethylenetriamine pentaacetic acid), tetrakis-(2- hydroxypropyl)-ethylenediamine ("Quadro ") or N,N,N',N'-tetrakis(2- hydroxyethyl)ethylenediamine, any salts thereof, or mixtures thereof, but the disclosure is not limited thereto.

[0086] The concentration of the complexing agent may range from about 0.001 M to about 2 M. In some embodiments, the complexing agent may have a concentration ranging from about 0.001 M to about 2 M, from about 0.005 M to about 1.5 M, from about 0.01 M to about 1 M, from about 0.02 M to about 0.8 M, from about 0.03 M to about 0.6 M, from about 0.05 M to about 0.4 M, from about 0.07 M to about 0.2 M, or in a certain range between the above values. When the complexing agent includes two or more reducing agents, the sum of concentrations of all complexing agent is within the above range.

[0087] The bulk mixture may further include a stabilizer. The stabilizer is selected from the group consisting of, for exam pie, mercaptobenzothiazole, thiourea, cyanide and/or ferrocyanide compounds, cobalt cyanide salts, polyethylene glycol derivatives, 4- nitrobenzoic acid, 3,5-dinitrobenzoic acid, 2,4-dinitrobenzoic acid, 2-hydroxy-3,5- dinitrobenzoic acid, 2-acetyl benzoic acid, 4-nitrophenol, 2,2'-bipyridy I, methylbutynol, and propionitrile. [0088] The concentration of the stabilizer may range from about 1 weight ppm to about 10000 weight ppm. In some embodiments, the stabilizer may have a concentration ranging from about 2 weight ppm to about 8000 weight ppm, from about 5 weight ppm to about 5000 weight ppm , from about 10 weight ppm to about 3000 weight ppm , from about 20 weight ppm to about 1000 weight ppm, from about 50 weight ppm to about 800 weight ppm, from about 100 weight ppm to about 500 weight ppm, or in a certain range between the above values.

[0089] The bulk mixture may further include a pH adjuster. The pH adjuster may include, for exam pie, an NaOH aqueous solution, a KOH aqueous solution, an NH4OH aqueous solution, an Mg(OH)2 aqueous solution, a Ca(OH)2 aqueous solution, a Ba(OH)2 aqueous solution, an AI(OH)s aqueous solution, or a mixture thereof. The pH adjuster may be added such that a pH of the bulk mixture ranges from about 8 to about 11.

[0090] In some embodiments, the bulk mixture may have a pH ranging from about 8 to about 11 , from about 8.5 to about 10.5, from about 9 to about 10, or in a certain range between the above values.

[0091] During the formation of the bulk layer 140, the temperature of the bulk mixture may range from about 10°C to about 75°C, from about 15°C to about 70°C, from about 20°C to about 65°C, from about 25°C to about 60°C, from about 30 °C to about 55°C, from about 35°C to about 50°C, or may have a certain temperature range between the above values.

[0092] When the temperature of the bulk mixture is too low, a reaction speed is decreased so that a formation speed of the bulk layer 140 may be decreased. When the temperature of the bulk mixture is too high, it may be economically disadvantageous.

[0093] The thickness of the bulk layer 140 may range from about 2.0 pm to about 10 pm. In some embodiments, the bulk layer 140 may have a thickness ranging from about 2.0 pm to about 10 pm, from about 2.2 pm to about 8 pm, from about 2.4 pm to about 7 pm, from about 2.6 pm to about 6 pm, from about 2.8 pm to about 5 pm, from about 3.0 pm to about 4.5 pm, or in a certain range between the above values.

[0094] The size of a crystal grain of the seed layer 130 may be quite smaller than the size of a crystal grain of the bulk layer 140. [0095] In detail, the average size of a crystal grain of the seed layer 130 may range from about 1 nm to about 150 nm , from about 2 nm to about 130 nm , from about 3 nm to about 100 nm , from about 5 nm to about 80 nm , from about 10 nm to about 50 nm , from about 20 nm to about 40 nm, or may be in a certain range between the above values.

[0096] Furthermore, the average size of a crystal grain of the bulk layer 140 may range from about 0.2 pm to about 1.6 pm, from about 0.3 pm to about 1.5 pm, from about 0.4 pm to about 1.4 pm, from about 0.5 pm to about 1.3 pm, from about 0.6 pm to about 1.2 pm, from about 0.7 pm to about 1.1 pm, from about 0.8 pm to about 1.0 pm, or may be in a certain range between the above values.

[0097] In a conventional electroless plating, a catalyst layer including a metal such as palladium (Pd), silver (Ag), is formed on a substrate and then a bulk layer is formed through a chemical reaction by providing a plating solution on the catalyst layer. In contrast, in the method of manufacturing a glass substrate structure described with reference to FIGS. 2A to 2E, since a catalyst layer including a metal such as Pd is not provided, a catalyst layer is not interposed between the glass substrate and the bulk layer.

[0098] FIGS. 3A to 3D are side cross-sectional views of a method of manufacturing a metallized substrate, according to an embodiment of the disclosure.

[0099] Referring to FIG. 3A, the adhesion promoter layer 120 and the seed layer 130 are sequentially formed on and above the glass substrate 110. As the above formation is described above in detail with reference to FIGS. 1 , 2A, and 2B, a redundant description thereof is om itted.

[00100] Referring to FIG. 3B, an etching mask pattern 150 may be formed on the seed layer 130. The etching mask pattern 150 may be, for example, a photoresist pattern. The photoresist pattern, as photosensitive polymer, may be negative photoresist or positive photoresist. In some embodiments, the etching mask pattern 150 may include a carbon-based material such as an amorphous carbon layer (ACL), a silicon nitride, a silicon oxide, and the like.

[00101] Referring to FIG. 3C, by sequentially etching the seed layer 130 and the adhesion promoter layer 120 using the etching mask pattern 150 as an etching mask, a seed layer pattern 130p and an adhesion promoter pattern 120p may be formed. The etching may be performed by a well-known anisotropic etching method. [00102] Then, the etching mask pattern 150 may be removed. The etching mask pattern 150 may be removed, for exam pie, by dissolving in a solvent or through ashing in an oxidizing atmosphere.

[00103] Referring to FIG. 3D, an acid treatment and a pre-dip process are performed on the surface of the seed layer pattern 130p that is exposed by removing the etching mask pattern 150, and thus the bulk layer 140 may be formed.

[00104] As the acid treatment and the pre-dip process are described above in detail with reference to FIGS. 1 , 2C, and 2D, redundant descriptions thereof are omitted.

[00105] The bulk layer 140 may be formed through the autocatalytic reaction using the seed layer pattern 130p without a catalyst. As the mechanism of the autocatalytic reaction is described above in detail with reference to FIGS. 1 and 2E, a redundant description thereof is omitted.

[00106] As the bulk layer 140 grows quite isotropically, while growing in a vertical direction, that is, a Z direction, the bulk layer 140 may also grow to a degree in a horizontal direction, that is, an X direction and/or a Y direction. However, the growth in the vertical direction may be faster than that in the horizontal direction. Furthermore, as the growth of the bulk layer 140 is isotropic to a degree, the bulk layer 140 may grow to have a surface 142 that is curved.

[00107] In some embodiments, the seed layer pattern 130p may be a line-and-space pattern, and the surface 142 that is curved may extend along the seed layer pattern 130p.

[00108] FIGS. 4A to 4D are side cross-sectional views of a method of manufacturing a metallized substrate, according to another embodiment of the disclosure.

[00109] Referring to FIG. 4A, the adhesion promoter layer 120, the seed layer 130, and the bulk layer 140 are sequentially formed on and above the glass substrate 110. As the above formation is described above in detail with reference to FIGS. 1 to 2E, a redundant description thereof is omitted.

[00110] Referring to FIG. 4B, the etching mask pattern 150 may be formed on the bulk layer 140. In other words the etching mask pattern 150 may be formed on the seed layer 130 with the bulk layer 140 therebetween.

[00111] The etching mask pattern 150 may be, for exam pie, a photoresist pattern. The photoresist pattern, as a photosensitive polymer, may be negative photoresist or positive photoresist. In some embodiments, the etching mask pattern 150 may be a carbon-based material such as an ACL, a silicon nitride, a silicon oxide, and the like. [00112] Referring to FIG. 4C, by sequentially etching the bulk layer 140, the seed layer 130, and the adhesion promoter layer 120 using the etching mask pattern 150 as an etching mask, a bulk layer pattern 140p, the seed layer pattern 130p, and the adhesion promoter pattern 120p may be formed. The etching may be performed by a well-known anisotropic etching method.

[00113] In some embodiments, the etching mask pattern 150 may be completely etched and disappear. In particular, before the bulk layer 140 or the seed layer 130 is sufficiently etched, the etching mask pattern 150 may be etched completely. In this case, as the seed layer 130 is etched using the bulk layer 140 as an etching mask, the seed layer pattern 130p may be formed.

[00114] Referring to FIG. 4D, the etching mask pattern 150 is removed. The etching mask pattern 150 may be removed, for example, by dissolving in a solvent or through ashing in an oxidizing atmosphere.

[00115] FIGS. 5A to 5D are side cross-sectional views of a method of manufacturing a metallized substrate, according to another embodiment of the disclosure.

[00116] Referring to FIG. 5A, the adhesion promoter layer 120 and the seed layer 130 are sequentially formed on and above the glass substrate 110. As the above formation is described above in detail with reference to FIGS. 1 , 2A, and 2B, a redundant description thereof is om itted.

[00117] Referring to FIG. 5B, the etching mask pattern 150 may be formed on the seed layer 130. The etching mask pattern 150 may be, for example, a photoresist pattern. The photoresist pattern, as a photosensitive polymer, may be negative photoresist or positive photoresist. In some embodiments, the etching mask pattern 150 may be a carbon-based material such as an ACL, a silicon nitride, a silicon oxide, and the like.

[00118] Referring to FIG. 5C, the bulk layer 140 may be formed to fill a gap of the etching mask pattern 150.

[00119] To form the bulk layer 140, first, acid treatment and pre-dip process may be performed on the surface of the seed layer 130 exposed through the gap. As the acid treatment and the pre-dip process are described above in detail with reference to FIGS. 1 , 2C, and 2D, redundant descriptions thereof are omitted.

[00120] In some embodiments, the acid treatment and the pre-dip process may be performed on the surface of the seed layer 130 before the etching mask pattern 150 is formed. In other words, after the acid treatment and the pre-dip process are performed on the surface of the seed layer 130 of FIG. 5A, the etching mask pattern 150 of FIG. 5B may be formed.

[00121] The bulk layer 140 may be formed through the autocatalytic reaction using the seed layer pattern 130p without a catalyst. As the mechanism of the autocatalytic reaction is described above in detail with reference to FIGS. 1 and 2E, a redundant description thereof is om itted.

[00122] Referring to FIG. 5D, the etching mask pattern 150 is removed. The etching mask pattern 150 may be removed, for example, by dissolving in a solvent or through ashing in an oxidizing atmosphere.

[00123] Then, the seed layer 130 and the adhesion promoter layer 120 that are exposed may be removed using the bulk layer 140 as an etching mask. In some embodiments, the seed layer 130 and the adhesion promoter layer 120 that are exposed may be removed through anisotropic etching. In some embodiments, as the seed layer 130 and the adhesion promoter layer 120 that are exposed have a thin thickness, the seed layer 130 and the adhesion promoter layer 120 may be removed through isotropic etching.

[00124] FIG. 6 is a scanning electron microscope (SEM) image of an enlarged crosssection of a stack structure manufactured by a method of manufacturing a metallized substrate, according to an embodiment of the disclosure.

[00125] Referring to FIG. 6, it is observed that the adhesion promoter layer 120, the seed layer 130, and the bulk layer 140 are formed on and above the glass substrate 110. Although both of the seed layer 130 and the bulk layer 140 are formed of copper, as the formation methods are different from each other, an interface is observed between the seed layer 130 and the bulk layer 140.

[00126] Furthermore, it is observed that the bulk layer 140 is formed to be much thick (about 4 pm) by electroless plating. As the thickness of a metal formed in typical electroless plating is much thinner (about 0.02 pm to about 0.5 pm) than the above thickness, the electroless plated metal may not be used alone as a wiring due to high resistance, and an additional stack thereon is required through electrolytic plating. In contrast, as the bulk layer 140 of a metallized substrate manufactured according to an embodiment of the disclosure is much thick, the bulk layer 140 may be used alone as a wiring. [00127] FIG. 7 is a SEM image of an enlarged cross-section of a stack structure manufactured by a method of manufacturing a metallized substrate, according to another embodiment of the disclosure.

[00128] Referring to FIG. 7, both of the seed layer 130 and the bulk layer 140 are formed of copper. The seed layer 130 is formed by sputtering to have a thickness of about 550 nm, and the bulk layer 140 is formed by the electroless plating method according to an embodiment of the disclosure to have a thickness of 3.75 pm.

[00129] As the seed layer 130 and the bulk layer 140 are much different from each other in the crystal grain size, the interface therebetween is noticeable. It may be seen that the size of most crystal grains of the seed layer 130 is much smaller than 200 nm. Furthermore, it is observed that the crystal grain of the bulk layer 140 generally has a size of hundreds of nanometers or more.

[00130] FIG. 8 is a SEM image of enlarged cross-sections of the seed layer 130 and the bulk layer 140 in a stack structure manufactured by a method of manufacturing a metallized substrate, according to another embodiment of the disclosure; FIG. 9 is a SEM image of a stack structure manufactured by the same method as that according to the embodiment of FIG. 8, except that a pre-dip process is not performed.

[00131] Referring to FIG. 8, it is observed that the seed layer 130 having relatively small crystal grains and the bulk layer 140 having relatively large crystal grains are sequentially formed, and the seed layer 130 and the bulk layer 140 are in close contact with each other without voids in the interface between that the seed layer 130 and the bulk layer 140.

[00132] Referring to FIG. 9, it is observed that several voids are formed in a row in the interface between that the seed layer 130 and the bulk layer 140. As these voids deteriorate adhesion between the seed layer 130 and the bulk layer 140, the bulk layer 140 may be separated from the seed layer 130.

[00133] FIGS. 10A and 10B are images of the surface of the bulk layer 140 when the pre-dip process is performed and when the pre-dip process is not performed, respectively.

[00134] Referring to FIG. 10A, it is observed that, when the pre-dip process is performed, the surface of the bulk layer 140 that is electroless plated is formed to be smooth. In contrast, referring to FIG. 10B, it is observed that, when the pre-dip process is not performed, a plurality of blisters are formed in the surface of the bulk layer 140 that is electroless plated. It is assumed that the formation of blisters is due to the voids described with reference to FIG. 9.

[00135] As the disclosure does not use a noble metal catalyst, electroless plating may be performed inexpensively, and thus a wiring structure having excellent interlayer adhesion may be obtained through the pre-dip process.

[00136] It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the following claims.