Etching solution composition and method for manufacturing a display device using the same

Abstract

To provide an etchant composition and a method for manufacturing a display device by use thereof.SOLUTION: An etchant composition comprises 8 to 15 wt.% of an inorganic acid compound, 2.5 to 8 wt.% of a sulfonic acid compound, 6 to 14 wt.% of a sulfate compound, 40 to 55 wt.% of an organic acid compound, and 0.01 to 0.06 wt.% of a metal or metal salt, with the rest consisting of water.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an etching solution composition and a method for manufacturing a display device using the same, and more particularly to an etching solution composition with improved product reliability and a method for manufacturing a display device using the same. [Background technology]

[0002] With the development of displays that display various electrical signal information, various flat-panel display devices with excellent characteristics such as thinness, lightness, and low power consumption are being researched and developed. Among them, organic light-emitting display devices are attracting attention as the next generation display devices due to their advantages such as lightness and thinness, wide viewing angle, and fast response speed.

[0003] Furthermore, as the display area of ​​a display device becomes larger and larger, various wirings and electrodes included in the display device must be made of materials having the lowest possible resistivity. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide an etching solution composition capable of etching a silver-containing laminated film, and a method for manufacturing a display device using the same. However, these problems are merely examples, and the scope of the present invention is not limited thereto. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided an etching solution composition comprising 8 wt % to 15 wt % of an inorganic acid compound, 2.5 wt % to 8 wt % of a sulfonic acid compound, 6 wt % to 14 wt % of a sulfate compound, 40 wt % to 55 wt % of an organic acid compound, 0.01 wt % to 0.06 wt % of a metal or metal salt, and the balance being water.

[0006] In this embodiment, the inorganic acid compound may include nitric acid.

[0007] In this embodiment, the sulfonic acid compound may include at least one of methanesulfonic acid, ethanesulfonic acid, and propanesulfonic acid.

[0008] In this embodiment, the sulfate compound may include at least one of potassium hydrogen sulfate, sodium hydrogen sulfate, and ammonium hydrogen sulfate.

[0009] In this embodiment, the organic acid compound may include at least one of acetic acid, citric acid, glycolic acid, malonic acid, lactic acid, and tartaric acid.

[0010] In this embodiment, the metal or metal salt may include at least one of ferric nitrate, ferric sulfate, copper, copper sulfate, and iron.

[0011] In this embodiment, the weight % ratio of the sulfate compound to the organic acid compound may be 1:4 to 1:5.

[0012] In this embodiment, the remaining amount of water may be 28% to 30% by weight.

[0013] According to another aspect of the present invention, there is provided a method for manufacturing a display device having a display area and a non-display area, the method including: forming thin film transistors on a substrate in the display area; forming a planarization layer on the thin film transistors; forming an electrode layer on the planarization layer; and etching the electrode layer with an etching solution composition to form pixel electrodes, wherein the etching solution composition contains 8 wt % to 15 wt % of an inorganic acid compound, 2.5 wt % to 8 wt % of a sulfonic acid compound, 6 wt % to 14 wt % of a sulfate compound, 40 wt % to 55 wt % of an organic acid compound, 0.01 wt % to 0.06 wt % of a metal or metal salt, and the balance being water.

[0014] In this embodiment, the electrode layer may be provided as a laminated film made up of a plurality of layers.

[0015] In this embodiment, the electrode layer includes a first conductive layer, a second conductive layer containing a first metal, and a third conductive layer, and the first conductive layer and the third conductive layer are also transparent electrodes or semi-transparent electrodes.

[0016] In this embodiment, the first metal may include silver.

[0017] In this embodiment, the etching solution composition can etch the first conductive layer, the second conductive layer, and the third conductive layer.

[0018] In this embodiment, the etching solution composition can etch the first conductive layer and the second conductive layer.

[0019] In this embodiment, the method may further include forming a wiring layer in the non-display area, and the electrode layer may be etched with the etchant composition while the wiring layer is exposed.

[0020] In this embodiment, the wiring layer may include a first layer including a second metal, a second layer including a third metal, and a third layer including the second metal.

[0021] In this embodiment, the second metal may include titanium, and the third metal may include aluminum.

[0022] In this embodiment, the thin film transistor includes a semiconductor layer, a gate electrode, a source electrode, and a drain electrode, and the wiring layer may include the same material as the source electrode or the drain electrode.

[0023] In this embodiment, the method may further include forming an intermediate layer on the pixel electrode and forming a counter electrode on the intermediate layer.

[0024] In this embodiment, the inorganic acid compound may include nitric acid.

[0025] In this embodiment, the sulfonic acid compound may include at least one of methanesulfonic acid, ethanesulfonic acid, and propanesulfonic acid.

[0026] In this embodiment, the sulfate compound may include at least one of potassium hydrogen sulfate, sodium hydrogen sulfate, and ammonium hydrogen sulfate.

[0027] In this embodiment, the organic acid compound may include at least one of acetic acid, citric acid, glycolic acid, malonic acid, lactic acid, and tartaric acid.

[0028] In this embodiment, the metal or metal salt may include at least one of ferric nitrate, ferric sulfate, copper, copper sulfate, and iron.

[0029] In this embodiment, the weight % ratio of the sulfate compound to the organic acid compound may be 1:4 to 1:5.

[0030] In this embodiment, the remaining amount of water may be 28% to 30% by weight.

[0031] Other aspects, features, and advantages in addition to those described above will become apparent from the following detailed description of the invention, the claims, and the drawings. [Effects of the Invention]

[0032] According to one embodiment of the present invention, the etching solution does not contain phosphoric acid, and silver deposition can be prevented during the etching of a laminated film containing a silver film. However, it goes without saying that the scope of the present invention is not limited to such an effect. [Brief explanation of the drawings]

[0033] [Figure 1]1 is a perspective view schematically illustrating a display device according to an embodiment of the present invention; [Figure 2] 1 is a plan view schematically illustrating a display device according to an embodiment of the present invention; [Figure 3] 1A to 1C are cross-sectional views schematically illustrating a method for manufacturing a display device according to an embodiment of the present invention. [Figure 4] 1A to 1C are cross-sectional views schematically illustrating a method for manufacturing a display device according to an embodiment of the present invention. [Figure 5] 1A to 1C are cross-sectional views schematically illustrating a method for manufacturing a display device according to an embodiment of the present invention. [Figure 6] 1A to 1C are cross-sectional views schematically illustrating a method for manufacturing a display device according to an embodiment of the present invention. [Figure 7] 1A to 1C are cross-sectional views schematically illustrating a method for manufacturing a display device according to an embodiment of the present invention. [Figure 8] 1A to 1C are cross-sectional views schematically illustrating a method for manufacturing a display device according to an embodiment of the present invention. [Figure 9A] 1 is a view illustrating a state in which a metal pattern is formed using an etching solution composition according to an embodiment of the present invention. [Figure 9B] 1 is a diagram illustrating a state in which a metal pattern is formed after adding 1,000 ppm of silver (Ag) to an etching solution composition according to an embodiment of the present invention. [Figure 10] 1 is a graph illustrating end point detection (EPD) and skew according to the number of processed wafers for an etching solution composition according to an embodiment of the present invention and an etching solution composition according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0034] The present invention can be modified in various ways and can have various embodiments, but specific embodiments are illustrated in the drawings and will be described in detail in the detailed description. The advantages, features, and methods of achieving the same of the present invention will become clearer with reference to the embodiments described in detail below together with the drawings. However, the present invention is not limited to the embodiments disclosed below and can be embodied in various forms.

[0035] In the following examples, the terms "first" and "second" are used not in a limiting sense but to distinguish one component from another.

[0036] In the following examples, the singular expression includes the plural expression unless the context clearly indicates otherwise.

[0037] In the following examples, terms such as "comprise" or "have" mean that the features or components described in the specification are present, but do not preclude the possibility that one or more other features or components may also be added.

[0038] In the following examples, when a part such as a film, region, or component is said to be on or above another part, this does not only include the case where it is directly on top of the other part, but also the case where another film, region, component, etc. is interposed between them.

[0039] In the drawings, the dimensions of components may be exaggerated or reduced for the sake of clarity. For example, the size and thickness of each component shown in the drawings are arbitrarily shown for the sake of clarity, and the present invention is not necessarily limited to those shown in the drawings.

[0040] In this specification, "A and / or B" means A, B, or A and B. Also, in this specification, "at least one of A and B" means A, B, or A and B.

[0041] In the following examples, the term "extending in a first or second direction" means not only that the wiring is extended in a straight line, but also that the wiring is extended in a zigzag or curved pattern along the first or second direction.

[0042] In the following examples, "on a plane" means when the target part is viewed from above, and "on a cross section" means when the target part is cut vertically and viewed from the side. In the following examples, "overlapping" includes overlapping "on a plane" and "on a cross section".

[0043] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When referring to the drawings, identical or corresponding components are designated by the same reference numerals.

[0044] FIG. 1 is a perspective view schematically illustrating a display device according to an embodiment of the present invention.

[0045] 1, the display device 1 may include a display area DA and a non-display area NDA arranged around the display area DA. The non-display area NDA may surround the display area DA. The display device 1 may provide an image using light emitted from a plurality of pixels P arranged in the display area DA, and the non-display area NDA is also an area where no image is displayed.

[0046] Hereinafter, an organic light emitting display device will be described as an example of a display device 1 according to an embodiment of the present invention, but the display device of the present invention is not limited thereto. As an embodiment, the display device 1 of the present invention may be an inorganic light emitting display (or inorganic EL display) or a quantum dot light emitting display. For example, the light emitting layer of the display element provided in the display device 1 may include an organic material, an inorganic material, a quantum dot material, an organic material and a quantum dot material, or an inorganic material and a quantum dot material.

[0047] 1 illustrates a display device 1 having a flat display surface, but the present invention is not limited thereto. In one embodiment, the display device 1 may include a stereoscopic display surface or a curved display surface.

[0048] When the display device 1 includes a three-dimensional display surface, the display device 1 may include a plurality of display regions pointing in different directions, for example, a polygonal prism-shaped display surface. In one embodiment, when the display device 1 includes a curved display surface, the display device 1 may be embodied in various forms, such as a flexible, foldable, or rollable display device.

[0049] 1 shows a display device 1 that can be applied to a mobile phone terminal. Although not shown, an electronic module, a camera module, a power supply module, etc. mounted on a main board can be placed in a bracket / case together with the display device 1 to form a mobile phone terminal. In particular, the display device 1 according to the present invention can be applied to large electronic devices such as televisions and monitors (desktop displays), as well as small and medium-sized electronic devices such as tablet PCs, automobile navigation devices, portable game consoles, and smart watches.

[0050] Although FIG. 1 shows a case where the display area DA of the display device 1 is rectangular, the shape of the display area DA may be circular, elliptical, or polygonal, such as triangular or pentagonal.

[0051] The display device 1 includes a plurality of pixels P arranged in a display area DA. Each of the plurality of pixels P may include an organic light-emitting diode (OLED). Each of the plurality of pixels P may emit light of, for example, red, green, blue, or white through the OLED. As described above, the pixel P in this specification may be understood to be a pixel that emits light of any one of red, green, blue, and white hues.

[0052] FIG. 2 is a plan view schematically illustrating a display device according to an embodiment of the present invention.

[0053] 2, the display device 1 includes a plurality of pixels P arranged in a display area DA. Each of the plurality of pixels P may include a display element such as an organic light-emitting diode (OLED). Each of the plurality of pixels P can emit light of, for example, red, green, blue, or white via the organic light-emitting diode (OLED). As described above, the pixel P in this specification can be understood as a pixel that emits light of any one of red, green, blue, and white hues.

[0054] Each pixel P may be electrically connected to an outer circuit arranged in the non-display area NDA, in which a first scan driving circuit 110, a first light emitting driving circuit 115, a second scan driving circuit 120, a terminal 140, a data driving circuit 150, a first power supply line 160, and a second power supply line 170 may be arranged.

[0055] The first scan driving circuit 110 may provide scan signals to each pixel P via scan lines SL. The first light-emitting driving circuit 115 may provide light-emitting control signals to each pixel P via light-emitting control lines EL. The second scan driving circuit 120 may be arranged parallel to the first scan driving circuit 110, sandwiching the display area DA. Some of the pixels P arranged in the display area DA may be electrically connected to the first scan driving circuit 110, and the remaining pixels P may be electrically connected to the second scan driving circuit 120. In one embodiment, the second scan driving circuit 120 may be omitted.

[0056] The first light emission driving circuit 115 may be arranged on the non-display area NDA, spaced apart from the first scan driving circuit 110 in the x direction. The first light emission driving circuit 115 may also be arranged alternately with the first scan driving circuit 110 in the y direction.

[0057] The terminal 140 may be disposed on one side of the substrate 100. The terminal 140 may be exposed without being covered by an insulating layer and electrically connected to a printed circuit board PCB. A terminal PCB-P of the printed circuit board PCB may be electrically connected to the terminal 140 of the display device 1. The printed circuit board PCB transmits signals or power from a controller (not shown) to the display device 1. Control signals generated by the controller may be transmitted to the first scan driving circuit 110, the first light emitting driving circuit 115, and the second scan driving circuit 120, respectively, via the printed circuit board PCB. The controller may provide a first power supply voltage (ELVDD) and a second power supply voltage (ELVSS) to the first power supply wiring 160 and the second power supply wiring 170, respectively, via a first connecting wiring 161 and a second connecting wiring 171. The first power supply voltage (ELVDD) may be provided to the pixel P through the driving voltage line PL connected to the first power supply line 160, and the second power supply voltage (ELVSS) may be provided to the counter electrode of the pixel P connected to the second power supply line 170. For example, the first power supply voltage (ELVDD) may be a driving voltage, and the second power supply voltage (ELVSS) may be a common voltage.

[0058] The data driving circuit 150 may be electrically connected to the data lines DL. A data signal from the data driving circuit 150 may be provided to each pixel P via a connecting line 151 connected to the terminal 140 and a data line DL connected to the connecting line 151.

[0059] 2, the data driving circuit 150 is illustrated as being disposed on the printed circuit board PCB, but in one embodiment, the data driving circuit 150 may be disposed on the substrate 100. For example, the data driving circuit 150 may be disposed between the terminal 140 and the first power supply wiring 160.

[0060] The first power supply wiring 160 may include a first sub-wiring 162 and a second sub-wiring 163 extending parallel to each other along the x-direction to sandwich the display area DA. The second power supply wiring 170 may be in the form of a loop with one side open, partially surrounding the display area DA.

[0061] 3 to 8 are cross-sectional views schematically illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0062] Hereinafter, the manufacturing method of the display device will be described in order with reference to FIGS.

[0063] According to one embodiment, a method for manufacturing a display device may include the steps of forming a thin film transistor TFT on a substrate 100 in a display area DA, forming a planarization layer 113 on the thin film transistor TFT, forming an electrode layer 180 on the planarization layer 113, and etching the electrode layer 180 with an etchant composition to form a pixel electrode 210.

[0064] First, referring to FIG. 3 , a step of forming a thin film transistor (TFT) on a substrate 100 in a display area DA may be performed. The substrate 100 may include a glass material, a ceramic material, a metal material, or a material having a flexible or bendable property. If the substrate 100 has a flexible or bendable property, the substrate 100 may include a polymer resin such as polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide (PI), polycarbonate, or cellulose acetate propionate. The substrate 100 may have a single-layer structure or a stacked structure of the above materials, and in the case of a stacked structure, an inorganic layer may further be included. In some embodiments, the substrate 100 may have a structure in which at least three layers of organic / inorganic / organic materials are stacked.

[0065] A buffer layer 101 may be formed on the substrate 100. The buffer layer 101 is located on the substrate 100 and may reduce or block penetration of foreign matter, moisture, or external air from below the substrate 100, and may provide a flat surface on the substrate 100. The buffer layer 101 may include an inorganic material such as an oxide or a nitride, an organic material, or an organic-inorganic composite material, and may be formed as a single layer structure or a stacked layer structure of an inorganic material or an organic material.

[0066] A thin film transistor (TFT) may be formed on the buffer layer 101. The thin film transistor (TFT) may include a semiconductor layer 134, a gate electrode 136, a source electrode 137, and a drain electrode 138. The thin film transistor (TFT) may be electrically connected to an organic light emitting diode (OLED) to be described later and drive the OLED.

[0067] The semiconductor layer 134 may include a channel region 131 formed on the buffer layer 101 and overlapping with the gate electrode 136, and a source region 132 and a drain region 133 disposed on both sides of the channel region 131 and containing impurities at a higher concentration than the channel region 131. Here, the impurities may include N-type impurities or P-type impurities. The source region 132 and the drain region 133 may be electrically connected to a source electrode 137 or a drain electrode 138, which will be described later.

[0068] The semiconductor layer 134 may include an oxide semiconductor and / or a silicon semiconductor. When the semiconductor layer 134 is formed of an oxide semiconductor, it may include an oxide of at least one material selected from the group consisting of indium (In), gallium (Ga), tin (Sn), zirconium (Zr), vanadium (V), hafnium (Hf), cadmium (Cd), germanium (Ge), chromium (Cr), titanium (Ti), and zinc (Zn). For example, the semiconductor layer 134 may be ITZO (InSnZnO) or IGZO (InGaZnO). When the semiconductor layer 134 is formed of a silicon semiconductor, it may include, for example, amorphous silicon (a-Si) or low-temperature polysilicon (LTPS) obtained by crystallizing amorphous silicon (a-Si).

[0069] A first insulating layer 103 may be formed on the semiconductor layer 134. The first insulating layer 103 may be made of silicon oxide (SiO2), silicon nitride (SiN x The first insulating layer 103 may contain at least one inorganic insulator selected from the group consisting of silicon oxynitride (SiON), aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), and zinc oxide (ZnO2). The first insulating layer 103 may be a single layer film or a multilayer film containing the inorganic insulators.

[0070] A gate electrode 136 may be formed on the first insulating layer 103. The gate electrode 136 may be formed as a single layer or a stacked layer using one or more metals selected from aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), and copper (Cu). The gate electrode 136 is also connected to a gate line that applies an electrical signal to the gate electrode 136.

[0071] A second insulating layer 105 may be formed on the gate electrode 136. The second insulating layer 105 may be made of silicon oxide (SiO2), silicon nitride (SiN x The second insulating layer 105 may contain at least one inorganic insulator selected from the group consisting of silicon oxynitride (SiON), aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), and zinc oxide (ZnO2). The second insulating layer 105 may be a single layer film or a multilayer film containing the aforementioned inorganic insulator.

[0072] A storage capacitor Cst may be formed on the first insulating layer 103. The storage capacitor Cst may include a lower electrode 144 and an upper electrode 146 overlapping the lower electrode 144. The lower electrode 144 and the upper electrode 146 of the storage capacitor Cst may be overlapped with the second insulating layer 105 interposed therebetween.

[0073] Although not shown in the drawings, the lower electrode 144 of the storage capacitor Cst may overlap the gate electrode 136 of the thin film transistor TFT, and the lower electrode 144 of the storage capacitor Cst may be integral with the gate electrode 136 of the thin film transistor TFT.

[0074] The upper electrode 146 of the storage capacitor Cst may include aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W) and / or copper (Cu), and may be a single layer or a laminated layer of the aforementioned materials.

[0075] A third insulating layer 107 may be formed on the upper electrode 146 of the storage capacitor Cst. The third insulating layer 107 may be formed of silicon oxide (SiO2), silicon nitride (SiN x The third insulating layer 107 may contain at least one inorganic insulator selected from the group consisting of silicon oxynitride (SiON), aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), and zinc oxide (ZnO2). The third insulating layer 107 may be a single layer film or a multilayer film containing the aforementioned inorganic insulator.

[0076] A source electrode 137 and a drain electrode 138 may be formed on the third insulating layer 107. The source electrode 137 and the drain electrode 138 may include a conductive material such as molybdenum (Mo), aluminum (Al), copper (Cu), or titanium (Ti), and may be formed as a single layer or multilayer including the above materials. The source electrode 137 and the drain electrode 138 may have a Ti / Al / Ti multilayer structure.

[0077] When the source electrode 137 and the drain electrode 138 are formed on the third insulating layer 107 in the display area DA, a wiring layer 139 may be formed on the third insulating layer 107 in the non-display area NDA in the same process. The wiring layer 139 may include the same material as the source electrode 137 or the drain electrode 138. The wiring layer 139 may include a first wiring layer 139a including a second metal, a second wiring layer 139b including a third metal, and a third wiring layer 139c including the second metal. The second metal and the third metal may include molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc. For example, the second metal may include titanium (Ti), and the third metal may include aluminum (Al). Therefore, the wiring layer 139 may be formed to have a three-layer stack structure of titanium (Ti), aluminum (Al), and titanium (Ti).

[0078] Below the wiring layer 139, wiring may be arranged in the same layer as the semiconductor layer 134, gate electrode 136, and upper electrode 146 in the display area DA, but this is omitted for convenience of explanation. The upper surface of the wiring layer 139 is exposed, and the electrode layer 180, which will be described later, may be etched using an etching solution composition.

[0079] Referring to FIG. 4, after forming the thin film transistor TFT on the substrate 100 in the display area DA, a planarization layer 113 may be further formed on the thin film transistor TFT.

[0080] A planarization layer 113 may be formed on the source electrode 137 and the drain electrode 138. The planarization layer 113 may be formed as a single layer or multiple layers of an organic or inorganic material. As an example, the planarization layer 113 may include a general-purpose polymer such as benzocyclobutene (BCB), polyimide (PI), hexamethyldisiloxane (HMDSO), polymethyl methacrylate (PMMA), or polystyrene (PS); a polymer derivative having a phenolic group; an acrylic polymer; an imide polymer; an aryl ether polymer; an amide polymer; a fluorine-based polymer; a p-xylene polymer; a vinyl alcohol polymer; or a blend thereof. Meanwhile, the planarization layer 113 may include silicon oxide (SiO2), silicon nitride (SiN x The planarization layer 113 may include, for example, silicon oxynitride (SiON), aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), or zinc oxide (ZnO2). After forming the planarization layer 113, chemical mechanical polishing may be performed to provide a flat upper surface. Although not shown, a contact metal layer may be formed on the planarization layer 113, and another planarization layer may be formed on the contact metal layer.

[0081] 5, after forming the planarization layer 113 on the thin film transistor TFT, a step of forming an electrode layer 180 on the planarization layer 113 may be further performed. The electrode layer 180 may include a reflective film made of aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), copper (Cu), or a compound thereof, and a transparent or semi-transparent conductive film formed on the reflective film. The transparent electrode or semi-transparent electrode may be at least one selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), and aluminum zinc oxide (AZO). As an example, the electrode layer 180 may include a first conductive layer 180a, a second conductive layer 180b disposed on the first conductive layer 180a and including a first metal, and a third conductive layer 180c disposed on the second conductive layer 180b. For example, the first conductive layer 180a and the third conductive layer 180c may include indium tin oxide (ITO), which is a transparent or semi-transparent conductive film, and the first metal may include silver (Ag). Therefore, the electrode layer 180 may be provided as a stacked structure of indium tin oxide (ITO) / silver (Ag) / indium tin oxide (ITO).

[0082] 6 and 7, after forming the electrode layer 180 on the planarization layer 113, a step of etching the electrode layer 180 with an etchant composition to form a pixel electrode 210 may be further performed.

[0083] As an example, in the step of etching the electrode layer 180 with an etching solution composition to form the pixel electrode 210, a photoresist pattern PR may be patterned on the electrode layer 180, and then the electrode layer 180 may be etched using the etching solution composition to form the pixel electrode 210.

[0084] The pixel electrode 210 may include a first layer 210a, a second layer 210b, and a third layer 210c. The first layer 210a, the second layer 210b, and the third layer 210c of the pixel electrode 210 may correspond to the first conductive layer 180a, the second conductive layer 180b, and the third conductive layer 180c of the electrode layer 180, respectively. The first layer 210a and the third layer 210c of the pixel electrode 210 may include indium tin oxide (ITO), and the second layer 210b may include silver (Ag).

[0085] The pixel electrode 210 can be formed by etching an electrode layer 180 formed as a stacked film, such as indium tin oxide (ITO) / silver (Ag) / indium tin oxide (ITO), using an etching solution composition according to an embodiment of the present invention.

[0086] Various wirings and electrodes included in a display device may contain silver (Ag). However, since wirings or electrodes containing silver (Ag) have weak adhesive strength with layers or films located above or below the wirings or electrodes, to compensate for this, the wirings or electrodes may be formed of a laminated film in which a film containing silver (Ag) is laminated with other conductive films.

[0087] Furthermore, various wiring and electrodes included in a display device can be formed using a patterning process such as photolithography, which includes an etching process. However, when the wiring or electrodes are composed of a stacked film consisting of multiple layers with different properties, there are limitations to forming wiring or electrodes with desired properties using a simultaneous etching process. Furthermore, because the etching solution used for wiring etching in the past contains phosphoric acid, the phosphoric acid can damage other wiring within the display device during the etching process. Through this process, silver ions are reduced and precipitated, which can cause defects due to silver particles. To prevent the generation of silver particles, a silver (Ag)-containing film and another conductive film can be etched sequentially, but this method significantly reduces the efficiency of the manufacturing process.

[0088] The etching solution composition according to an embodiment of the present invention can simultaneously etch an electrode layer formed as a stacked film, such as indium tin oxide (ITO) / silver (Ag) / indium tin oxide (ITO), while preventing silver (Ag) ions from being reduced and precipitated, thereby improving the reliability of a display device.

[0089] An etching solution composition according to an embodiment of the present invention may include 8 wt % to 15 wt % of an inorganic acid compound, 2.5 wt % to 8 wt % of a sulfonic acid compound, 6 wt % to 14 wt % of a sulfate compound, 40 wt % to 55 wt % of an organic acid compound, 0.01 wt % to 0.06 wt % of a metal or metal salt, and the balance being water.

[0090] The inorganic acid compound may include nitric acid. Nitric acid is an oxidizing agent and can be used to etch a silver (Ag) layer and a conductive film. For example, nitric acid can oxidize the silver (Ag) layer and the conductive film to perform wet etching. The nitric acid content may be 8 wt% to 15 wt% based on the total weight of the etching solution composition. If the nitric acid content exceeds 15 wt%, the etching rate of the transparent conductive film or translucent conductive film is accelerated, and undercutting occurs in the conductive film above and below the silver (Ag) layer, which can cause problems in subsequent processes. If the nitric acid content is less than 8 wt%, the etching rate of the silver (Ag) and the conductive film decreases, resulting in reduced etching uniformity depending on the position on the substrate, and the occurrence of speckles or irregularities. Therefore, if the nitric acid content is 8 wt% to 15 wt%, the etching rate can be easily controlled and the silver (Ag) and the conductive film can be uniformly etched.

[0091] The sulfonic acid compound may include at least one of methanesulfonic acid, ethanesulfonic acid, and propanesulfonic acid.

[0092] The sulfonic acid compound can be used as an etching agent to etch silver (Ag) oxidized by nitric acid and a conductive film. The sulfonic acid compound slows the decomposition rate of nitric acid, thereby maintaining a constant etching rate. The sulfonic acid compound can be included in an amount of 2.5 to 8 wt % based on the total weight of the etching solution composition. If the sulfonic acid compound content is high, the etching rate of silver (Ag) becomes excessively fast, which can result in chips on the conductive film above and / or below the silver (Ag) or wiring defects due to over-etching of the silver (Ag). If the sulfonic acid compound content is low, the decomposition suppression effect against nitric acid is reduced, resulting in decreased stability and the generation of silver (Ag) residue. Therefore, when the sulfonic acid compound is included in an etching solution composition in an amount of 2.5 to 8 wt %, the etching rate of silver (Ag) and a conductive film can be easily controlled and defects due to the generation of silver (Ag) residue and re-adsorption of silver (Ag) can be prevented.

[0093] The sulfate compound may include at least one of potassium hydrogen sulfate, sodium hydrogen sulfate, and ammonium hydrogen sulfate.

[0094] The sulfate compound can be used as an etchant for etching transparent and semitransparent conductive films. The sulfate compound can cause an etch stop phenomenon of silver (Ag). Here, the etch stop phenomenon means that the skew, which is the distance between the edge of a photoresist pattern and the edge of a silver (Ag) layer, does not increase over time. Therefore, even if the etching time increases during the etching process, side etch of silver (Ag) can be prevented from increasing. That is, by including a sulfate compound, the etching solution composition according to one embodiment of the present invention can realize etch stop properties and control the etching rate, thereby adjusting side etch.

[0095] The content of the sulfate compound may be 6 wt% to 14 wt% based on the total weight of the etching solution composition. If the content of the sulfate compound is greater than 14 wt%, the etching rate of the conductive film may be too fast, resulting in poor erosion. If the content of the sulfate compound is less than 6 wt%, the etching rate of the conductive film may be reduced, resulting in the generation of silver (Ag) and conductive film residue. Therefore, when the content of the sulfate compound in the etching solution composition is 6 wt% to 14 wt%, the etching rate may be easily controlled, etch-stop properties may be achieved, and silver (Ag) and the conductive film may be uniformly etched.

[0096] The organic acid compound may include at least one of acetic acid, citric acid, glycolic acid, malonic acid, lactic acid, and tartaric acid. For example, the organic acid compound may include acetic acid and citric acid.

[0097] The organic acid compound can be used as an etching agent for etching silver (Ag). The organic acid compound can be used to etch silver (Ag) that has been oxidized with nitric acid as described above.

[0098] The content of the organic acid compound may be 40 wt % to 55 wt % based on the total weight of the etching solution composition. If the content of the organic acid compound is less than 40 wt %, uneven etching rate depending on the position on the substrate may occur, resulting in mottling. If the content of the organic acid compound is more than 55%, over-etching may occur. Therefore, when the organic acid compound is included in the etching solution composition in an amount of 40 wt % to 55 wt %, it is easy to control the etching rate of silver (Ag) and defects due to the generation of silver (Ag) residue and re-adsorption can be prevented.

[0099] The metal or metal salt may include at least one of metals such as iron (Fe), copper (Cu), or metal salts of iron (Fe), copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), manganese (Mn), etc. For example, the metal or metal salt may include at least one of ferric nitrate, ferric sulfate, copper, copper sulfate, and iron.

[0100] The metal or the metal salt can be used as an oxidizing agent for silver (Ag). The metal or the metal salt can be used as a co-oxidizing agent for the aforementioned nitric acid.

[0101] The content of the metal or metal salt may be 0.01 wt % to 0.06 wt % of the etching solution composition. If the content of the metal or metal salt is less than 0.01 wt %, etching uniformity may be reduced. If the content of the metal or metal salt is more than 0.06 wt %, etch stop properties may be reduced. Therefore, when the metal or metal salt is included in the etching solution composition at 0.01 wt % to 0.06 wt %, it is easy to control the etching rate of silver (Ag), defects due to silver (Ag) residue and silver (Ag) re-adsorption can be prevented, and etch stop properties can be improved.

[0102] The etching solution composition according to an embodiment of the present invention may contain water. The water is contained such that the sum of the weight percentages of the remaining components of the etching solution composition excluding water and the weight percentage of water is 100 weight%. Ultrapure water may be used as the water used in the etching solution composition. The water contained in the etching solution composition may serve to activate the sulfate compound.

[0103] In one embodiment, the water content may be 28 wt % to 30 wt % of the etchant composition. If the water content is less than 28 wt %, the etch stop properties may be reduced. If the water content is more than 30 wt %, problems such as the generation of silver residue may occur. Therefore, if the water content in the etchant composition is 28 wt % to 30 wt %, defects due to silver residue can be prevented and etch stop properties can be achieved.

[0104] In one embodiment, the weight percent ratio of the sulfate compound to the organic acid compound may be 1:4 to 1:5. When the weight percent ratio of the sulfate compound to the organic acid compound satisfies the above-mentioned 1:4 to 1:5, the etch-stop characteristics are maintained not only at the initial stage of etching but also over the accumulated number of processed wafers, and one-sided etching can be controlled.

[0105] When the content of metal or metal salt is maintained at 600 ppm or less and water is contained in an amount of 28 to 30 wt % based on the total weight of the etching solution composition, one-sided etching can be controlled more effectively.

[0106] An etching solution composition according to one embodiment will be described below with reference to Tables 1 and 2.

[0107] [Experimental Example 1] Etching solution compositions according to Examples 1 to 4 and Comparative Examples 1 to 7 were prepared as shown in Table 1 below. % in Table 1 below is by weight.

[0108] [Table 1]

[0109] Comparative Examples 1 and 2 have a sulfate to organic acid compound ratio of 1:3.9 and 1:5.2, respectively, which are outside the range of 1:4 to 1:5. Comparative Example 3 has an organic acid compound content of less than 40 wt% and a sulfate compound content of less than 6 wt%, and Comparative Example 4 has an organic acid compound content of more than 55 wt%. Comparative Example 5 has no metal or metal salt added, Comparative Example 6 has a metal or metal salt content of more than 0.06 wt%, and Comparative Example 7 has a water content of less than 28 wt%.

[0110] A triple layer of indium tin oxide (ITO) / silver (Ag) / ITO was formed on a substrate, and a photoresist was patterned on the triple layer to prepare a test piece. An etching process was then performed using a first etching solution and a second etching solution. Here, the first etching solution corresponds to the etching solution composition of Examples 1 to 4 and Comparative Examples 1 to 7, and the second etching solution corresponds to the etching solution obtained by dissolving 1,000 ppm of silver (Ag) powder in the etching solution composition of Examples 1 to 4 and Comparative Examples 1 to 7, assuming that the etching process had been performed for a long period of time.

[0111] 1) Measurement and evaluation criteria for side etching and etch stop The first and second etching solutions were placed in a spray etching experimental device (Model: ETCHER (TFT), SEMES) and heated to 40°C. The sample was then etched when the temperature reached 40°C ± 0.1°C. After etching of the sample was completed, the sample was over-etched by 50% and 100%, and the side etching was measured using a scanning electron microscope (Model: SU-8010, HITACHI). The side etching corresponds to the distance from the edge of the patterned photoresist to the edge of the etched silver (Ag) pattern.

[0112] A suitable range for side etching is 0.3 μm or less, and side etching greater than 0.3 μm is considered poor. Also, etch stop is considered good if the change in side etching at 100% overetching compared to 50% overetching is 0.05 μm or less, and poor if the change in side etching at 100% overetching compared to 50% overetching is greater than 0.05 μm.

[0113] 2) Measurement and evaluation standards for silver (Ag) and indium tin oxide (ITO) residues The first and second etching solutions were placed in a spray etching experimental system (Model: ETCHER (TFT), SEMES) and heated to 40°C. The etching process was performed on the specimens when the temperature reached 40°C ± 0.1°C. The total etching time was 85 seconds. After 85 seconds of etching, the specimens were removed and washed with deionized water. The specimens were then dried using a hot air dryer and the photoresist was removed using a photoresist stripper. After washing and drying, residue (etching residue), which refers to the remaining silver (Ag) and indium tin oxide (ITO) in areas not covered by the photoresist, was measured using a scanning electron microscope (Model: SU-8010, Hitachi). A non-measured residue was evaluated as good, and a measurable residue was evaluated as poor.

[0114] 3) Measurement and evaluation criteria for silver (Ag) resorption The first and second etching solutions were placed in a spray etching experimental device (Model: ETCHER (TFT), SEMES) and heated to 40°C. The etching process was performed on the specimens when the temperature reached 40°C ± 0.1°C. The total etching time was 85 seconds. After 85 seconds of etching time had elapsed, the specimens were removed and washed with deionized water. They were then dried using a hot air dryer. After washing and drying, the number of silver (Ag) particles adsorbed on the upper titanium (Ti) layer of the exposed titanium (Ti) / aluminum (Al) / titanium (Ti) triple layer was measured using a scanning electron microscope (Model: SU-8010, HITACHI). In this case, if the number of measured silver (Ag) particles was 10 or less, it was evaluated as good, and if the number of measured silver (Ag) particles was more than 10, it was evaluated as poor.

[0115] [Table 2]

[0116] In Table 2, O indicates good and X indicates bad. Referring to Table 2, when the ratio of the sulfate compound to the organic acid compound in the etching solution composition was 1:4 to 1:5 as in Examples 1 to 4, the side etching, silver (Ag) and indium tin oxide (ITO) residue, and silver (Ag) readsorption characteristics of the etching solutions (first etching solution and second etching solution) met the evaluation criteria. When the ratio of the sulfate compound to the organic acid compound in the etching solution composition was outside the range of 1:4 to 1:5 as in Comparative Examples 1 and 2, the etching performance deteriorated, and the first etching solution and second etching solution experienced poor silver (Ag) and indium tin oxide (ITO) residue and silver (Ag) readsorption, or the etching rate was uncontrollable. Even the first etching solution sometimes had poor side etching or etch-stop characteristics.

[0117] As in Comparative Example 3, when the content ratio of the sulfate compound to the organic acid compound was satisfactory but the contents of the sulfate compound and the organic acid compound contained in the etching solution composition were low, the properties regarding side etching, etch stop, silver (Ag) and indium tin oxide (ITO) residue, and silver (Ag) re-adsorption were not satisfactory.

[0118] Furthermore, as in Comparative Example 4, even if the content ratio of the sulfate compound to the organic acid compound is satisfactory, when the content of the organic acid compound in the etching solution composition is high and the content of water is low, there is a problem that the solid substance is not dissolved.

[0119] When the etching solution composition does not contain a metal or a metal salt, as in Comparative Example 5, residues of silver (Ag) and indium tin oxide (ITO) or poor re-adsorption of silver (Ag) may occur in the first etching solution or the second etching solution.

[0120] When the content of metal or metal salt contained in the etching solution composition exceeds 0.06 wt % as in Comparative Example 6, side etching and poor etch stop may occur.

[0121] Furthermore, when the content of other substances is sufficient but the content of water is less than 28 wt %, as in Comparative Example 7, the etch stop surface may be somewhat poor.

[0122] 9A is a diagram illustrating a metal pattern formed using an etching solution composition according to an embodiment of the present invention. FIG. 9B is a diagram illustrating a metal pattern formed after adding 1,000 ppm of silver (Ag) to an etching solution composition according to an embodiment of the present invention. FIG. 9B is a diagram illustrating a metal pattern formed after adding 1,000 ppm of silver (Ag) to an etching solution composition according to an embodiment of the present invention to check the etching characteristics of the etching solution composition according to the number of wafers processed.

[0123] Referring to FIG. 9A, when a metal pattern is formed by etching a thin film having a three-layer structure of indium tin oxide (ITO) / silver (Ag) / indium tin oxide (ITO) using an etching solution composition according to an embodiment of the present invention, it can be seen that almost no silver (Ag) particles are deposited.

[0124] Furthermore, referring to FIG. 9B, it can be seen that silver (Ag) particles are hardly precipitated even when the number of wafers treated with the etching solution composition according to an embodiment of the present invention increases.

[0125] 10 is a graph showing EPD (end point detection) and skew as a function of the number of wafers processed for an etching solution composition according to an embodiment of the present invention and an etching solution composition according to a comparative example. More specifically, FIG. 10 is a graph showing EPD and skew as a function of the number of wafers processed for a conventional etching solution composition (Comparative Example 8) and an etching solution composition according to an embodiment of the present invention (Example 5). The conventional etching solution composition (Comparative Example 8) is an etching solution composition containing a phosphoric acid-based composition, and the etching solution composition according to an embodiment of the present invention (Example 5) is an etching solution composition containing 8 wt % to 15 wt % of an inorganic acid compound, 2.5 wt % to 8 wt % of a sulfonic acid compound, 6 wt % to 14 wt % of a sulfate compound, 40 wt % to 55 wt % of an organic acid compound, 0.01 wt % to 0.06 wt % of a metal or metal salt, and the balance being water. Here, in order to measure EPD and skew depending on the number of processed wafers, silver (Ag) was added to a conventional etching solution composition (Comparative Example 8) and an etching solution composition according to an embodiment of the present invention (Example 5) at 0 ppm, 200 ppm, 400 ppm, and 600 ppm.

[0126] 10, it can be seen that the conventional etching solution composition (Comparative Example 8) maintained an EPD of 27 or 28 and a skew of 0.18 to 0.20 even when the added silver (Ag) increased from 0 ppm to 600 ppm. However, with the conventional etching solution composition (Comparative Example 8), as the number of wafers processed increased, defects due to silver (Ag) particles occurred, and the actual number of wafers processed with the conventional etching solution composition (Comparative Example 8) was only about 300.

[0127] It can be seen that the etching solution composition according to one embodiment of the present invention (Example 5) maintains an EPD of 24 or 25 and a skew of 0.17 to 0.20 even when the added silver (Ag) is increased from 0 ppm to 600 ppm. In other words, it can be seen that by using the etching solution composition according to one embodiment (Example 5) multiple times, the physical properties required of the etching solution composition are maintained constant even when the silver (Ag) ion concentration increases. The etching solution composition according to one embodiment of the present invention (Example 5) does not cause defects due to silver (Ag) particles even when the number of processed wafers is increased, so the number of processed wafers can be increased by about three times compared to conventional etching solution compositions.

[0128] Furthermore, the etching solution composition according to one embodiment (Example 5) has a smaller EPD than the conventional etching solution composition (Comparative Example 8). Therefore, when the etching solution composition according to one embodiment (Example 5) is used, the time required for the etching process can be shortened, thereby improving the efficiency of the manufacturing process of the display device.

[0129] However, when etching a triple layer consisting of indium tin oxide (ITO) / silver (Ag) / indium tin oxide (ITO) using the etching solution composition according to an embodiment of the present invention, a mouse bite phenomenon may occur in a part of the upper indium tin oxide (ITO) due to non-uniform deposition of the upper indium tin oxide (ITO) and impurities such as dust. The etching solution composition may seep into pinholes formed by the mouse bite, causing partial etching of silver (Ag).

[0130] Therefore, although the present invention etches a triple layer consisting of indium tin oxide (ITO) / silver (Ag) / indium tin oxide (ITO) using an etching solution composition, the upper indium tin oxide (ITO) is etched using a separate etching solution, and then the silver (Ag) / indium tin oxide (ITO) is etched using an etching solution composition according to one embodiment, thereby preventing the occurrence of the mouse bite phenomenon.

[0131] In the past, etching processes have been performed using etchant compositions containing 18 to 25 wt % of a first organic acid compound, 15 to 20 wt % of a second organic acid compound, 8.1 to 9.9 wt % of an inorganic acid compound, 1 to 4.9 wt % of a sulfonic acid compound, 10 to 20 wt % of a hydrogen sulfate compound, 1 to 5 wt % of a nitrogen-containing dicarbonyl compound, 1 to 5 wt % of an amino acid derivative compound, 0.1 to 2 wt % of an iron-containing oxidant compound, and the balance water. Conventional etchant compositions may contain 0.1 to 2 wt % of the iron-containing oxidant compound to prevent the formation of silver (Ag) residue. However, the iron-containing oxidant compound contained in conventional etchant compositions can cause etch-stop failures. Therefore, conventional etchant compositions may contain a nitrogen-containing dicarbonyl compound and an amino acid derivative compound.

[0132] The nitrogen-containing dicarbonyl compounds and amino acid derivative compounds contained in conventional etching solution compositions can function as corrosion inhibitors. The nitrogen-containing dicarbonyl compounds and amino acid derivative compounds contained in conventional etching solution compositions can form complexes with metals and function as etching regulators for silver (Ag), indium tin oxide (ITO), and aluminum (Al). However, the dicarbonyl compounds and amino acid derivative compounds contained in conventional etching solution compositions have problems such as reduced etching rates and the generation of silver (Ag) residues.

[0133] The etching solution composition according to an embodiment of the present invention does not contain a nitrogen-containing dicarbonyl compound or an amino acid derivative compound, and implements an etch stop by adjusting the content of a sulfate compound and water, thereby preventing excessive etching and implementing low skew, and at the same time, providing a display device with high resolution.

[0134] 8, after etching the electrode layer 180 with an etchant composition to form the pixel electrode 210, steps of forming an intermediate layer 220 on the pixel electrode 210 and forming a counter electrode 230 on the intermediate layer 220 may be further performed. The pixel electrode 210, the intermediate layer 220, and the counter electrode 230 may form an organic light emitting diode (OLED).

[0135] A pixel division film 190 is formed on the planarization layer 113. The pixel division film 190 may have an opening that exposes at least a portion of the pixel electrode 210. The area exposed by the opening in the pixel division film 190 may be defined as an emissive area. The periphery of the emissive area may be a non-emissive area, which may surround the emissive area. That is, the display area DA may include multiple emissive areas and the surrounding non-emissive areas. The pixel division film 190 increases the distance between the top of the pixel electrode 210 and the counter electrode 230, thereby preventing arcing and other problems from occurring at the edge of the pixel electrode 210. The pixel division film 190 may be made of an organic insulating material, such as polyimide, polyamide, acrylic resin, benzocyclobutene, HMDSO (hexamethyl disiloxane), or phenolic resin, and may be formed by a method such as spin coating.

[0136] An intermediate layer 220 may be disposed on the pixel electrode 210, at least a portion of which is exposed by the pixel partition film 190. The intermediate layer 220 may include an emitting layer, and a first functional layer and a second functional layer may be selectively disposed above and below the emitting layer.

[0137] As an example, the intermediate layer 220 may be disposed on the pixel electrode 210, at least a portion of which is exposed by the pixel partition film 190. More specifically, the light-emitting layer of the intermediate layer 220 may be formed on the pixel electrode 210, at least a portion of which is exposed by the pixel partition film 190.

[0138] A first functional layer may be formed below the light-emitting layer, and a second functional layer may be formed above the light-emitting layer. The first and second functional layers disposed above and below the light-emitting layer may be collectively referred to as organic functional layers.

[0139] The first functional layer may include a hole injection layer (HIL) and / or a hole transport layer (HTL), and the second functional layer may include an electron transport layer (ETL) and / or an electron injection layer (EIL).

[0140] The light-emitting layer may comprise an organic material containing a fluorescent or phosphorescent material that emits red, green, blue, or white light. The light-emitting layer may comprise a small molecule organic material or a polymer organic material.

[0141] When the light-emitting layer includes a small molecule organic material, the intermediate layer 220 may have a structure in which a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, etc. are laminated in a single or composite structure, and the small molecule organic material may include various organic materials including copper phthalocyanine (CuPc), N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine (NPB), tris-8-hydroxyquinoline aluminum (Alq3), etc. Such a layer may be formed by a vacuum deposition method.

[0142] When the light-emitting layer includes a polymer organic material, the intermediate layer 220 may generally have a structure including a hole transport layer and a light-emitting layer. Here, the hole transport layer may include poly(3,4-ethylenedioxythiophene) (PEDOT), and the light-emitting layer may include a polymer material such as a PPV (polyphenylene vinylene)-based material or a polyfluorene-based material. Such a light-emitting layer may be formed by a screen printing method, an inkjet printing method, a laser-induced thermal imaging (LITI) method, or the like.

[0143] An opposing electrode 230 may be formed on the intermediate layer 220. The opposing electrode 230 may be formed on the intermediate layer 220 and may be formed to cover the entire intermediate layer 220. The opposing electrode 230 may be formed on the upper portion of the display area DA and may be formed to cover the entire display area DA. That is, the opposing electrode 230 may be integrally formed over the entire display area using an open mask to cover a plurality of pixels P arranged in the display area DA.

[0144] The counter electrode 230 may include a conductive material with a low work function. For example, the counter electrode 230 may include a (semi-)transparent layer containing silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), or an alloy thereof. Alternatively, the counter electrode 230 may further include a transparent or semi-transparent conductive layer such as ITO, IZO, ZnO, or In2O3 on the (semi-)transparent layer containing the aforementioned material.

[0145] Although the present invention has been described with reference to the embodiments shown in the drawings, they are merely illustrative, and those skilled in the art will recognize that various modifications and equivalent embodiments are possible. Therefore, the true technical scope of the present invention is defined by the technical spirit of the claims.

[0146] According to one preferred embodiment, the following is true.

[0147] In relation to one specific embodiment, the background and problems of the present invention are as follows (i) to (v).

[0148] (i) In flat panel displays such as organic light-emitting displays, the use of silver, which has low resistivity, for pixel electrodes has been considered, particularly in order to accommodate larger displays. In particular, a silver (Ag) layer is sandwiched between transparent conductive films such as ITO, IZO, ZnO, In2O3, IGO, and AZO (Figure 5,

[0081] ).

[0149] (ii) It is efficient in terms of process to wet etch the silver (Ag) layer and the transparent conductive film such as ITO at the same time.

[0150] (iii) When a typical phosphoric acid-based etching solution is used for this wet etching, the silver concentration in the etching solution increases with the number of processed wafers, and defects due to silver (Ag) particles are likely to occur (Comparative Example 8,

[0127] ).

[0151] (iv) Instead of phosphoric acid-based etching solutions, it has been considered to use etching solutions containing nitric acid, which oxidizes silver, and an organic acid, which etches silver, and a sulfate compound or sulfonic acid compound, which etches ITO, etc. (

[0090] and

[0096] , and

[0091] to

[0095] ).

[0152] (v) However, it was not easy to obtain an etching solution that achieved all of the following (a) to (c): (a) It suppresses the generation of silver (Ag) particles ("re-adsorption of silver (Ag)") that accompanies an increase in silver concentration during etching, thereby improving manufacturing efficiency. (

[0114] ) (b) Suppressing side etching of the silver (Ag) layer, i.e., realizing an etch stop. (

[0111] ) (c) Etching residues are prevented from being generated on either the silver layer or the transparent conductive layer. (

[0113] )

[0153] In view of the above problems, and as a result of thorough investigation, the following A1 to A5, A1 to A6, or A1 to A7 were attempted as particularly preferred embodiments, and A8 to A9 were also attempted as necessary.The effects of these were then confirmed through experiments.

[0154] A1 Contains 40 to 55% by weight of organic acids such as acetic acid and citric acid. (

[0097] to

[0098] ) A2 Contains 8 to 15% by weight of nitric acid. (

[0090] ) A3 Contains 6 to 14% by weight of hydrogen sulfate (potassium hydrogen sulfate, sodium hydrogen sulfate, and / or ammonium hydrogen sulfate). (

[0093] to

[0095] ) A4 Contains 2.5 to 8% by weight of sulfonic acid compounds (methanesulfonic acid, ethanesulfonic acid, and / or propanesulfonic acid). (

[0091] to

[0092] ) A5 Contains 0.01 to 0.06% by weight (100 to 600 ppm) of iron (Fe) and / or copper (Cu) and / or their nitrates and / or sulfates. (

[0099] to

[0101] and

[0105] )

[0155] A6 The weight percentage ratio of hydrogen sulfate to organic acid is 1:4 to 1:5. (See

[0104] and the right end of Table 1.) A7 Contains 28 to 30% by weight of water. (

[0103] and

[0105] )

[0156] A8 The upper transparent conductive film can be etched using a conventional etching solution having the following composition, for example, and then the silver (Ag) layer and the lower transparent conductive layer can be etched using the etching solution of the present invention having the above composition. Here, phosphoric acid or a phosphate can be used as the inorganic acid compound. (

[0129] to

[0131] and

[0125] ) 18% to 25% by weight of a first organic acid compound; 15% to 20% by weight of a second organic acid compound; 8.1% to 9.9% by weight of an inorganic acid compound; 1% to 4.9% by weight of a sulfonic acid compound; 10% to 20% by weight of a hydrogen sulfate compound, 1% to 5% by weight of nitrogen-containing dicarbonyl compounds, 1% to 5% by weight of an amino acid derivative compound; 0.1% to 2% by weight of an iron-containing oxidizer compound; and the balance is water.

[0157] A9 Maintain the concentration of silver (Ag) dissolved in the etching solution at 1,000 ppm or less, or 600 ppm or less (FIG. 9B,

[0122] and

[0105] ).

[0158] Note that "0 ea" at the bottom of FIG. 9A of the present application means that the number of silver (Ag) particles detected was "0 per substrate to be processed." Similarly, "1 ea" at the bottom of FIG. 9B means that the number was "1 per substrate to be processed." The etching solutions used in FIGS. 9A and 9B have the same compositions as those in Examples 2 and 3 of Table 1.

[0159] On the other hand, in the experiment for obtaining the results of Fig. 10, the etching solution of Example 5 also had the same composition as Examples 2 and 3 in Table 1. Moreover, the etching solution of Comparative Example 8 had the composition of A8 described above, as described in

[0131] , and used phosphoric acid as the inorganic acid.

[0160] As suggested by the results of Figure 10, when the etching solution composition of the present embodiment (Example 5) is used, problems such as silver (Ag) particles hardly occur, even when silver (Ag) is dissolved at a concentration of 600 ppm. In contrast, when the conventional etching solution composition (Comparative Example 8) is used, the upper limit of the silver (Ag) concentration needs to be about 200 ppm. Therefore, assuming that the amount of silver (Ag) dissolved into the etching solution in one treatment is constant, the etching solution composition of the present embodiment (Example 5) can treat approximately three times as many substrates as the conventional composition (Comparative Example 8).

[0161] The "EPD (end point detection)" in Figure 10 and the related explanations (

[0125] to

[0128] ) can be determined as follows. First, an etching end point detector using a laser light source and a photodetector is used to detect, from the spectral change of the reflected laser light, that the exposed silver (Ag) layer not covered by the resist and the underlying transparent / semitransparent transparent conductive layer have essentially disappeared. Then, based on this detection, the number of substrates that can be completely etched within a specified time is calculated using a bench-scale etching device. [Explanation of symbols]

[0162] 100 boards 180 Electrode layer 180a First conductive layer 180b Second conductive layer 180c 3rd conductive layer 190 pixel partition membrane 210 pixel electrode 220 Middle Class 230 Counter electrode

Claims

1. An etching solution composition for etching a laminated film including a first transparent conductive layer made of a metal oxide and a metal layer containing silver (Ag) covering the first transparent conductive layer from above, 8% to 15% by weight of nitric acid; 2.5% to 8% by weight of a sulfonic acid compound; 6% to 14% by weight of a sulfate compound; 40% to 55% by weight of an organic acid compound; 0.01% to 0.06% by weight of a metal or metal salt; 28% to 30% by weight of water; the sulfonic acid compound comprises at least one of methanesulfonic acid, ethanesulfonic acid, and propanesulfonic acid; the sulfate compound comprises at least one of potassium hydrogen sulfate, sodium hydrogen sulfate, and ammonium hydrogen sulfate; the organic acid compound is at least one of acetic acid, citric acid, glycolic acid, malonic acid, lactic acid, and tartaric acid; the metal or metal salt is at least one of ferric nitrate, ferric sulfate, and copper; the weight percent ratio of the sulfate compound to the organic acid compound is 1:4 to 1:5; The concentration of silver (Ag) dissolved in the etching solution is 1,000 ppm or less, The etching solution composition does not contain a nitrogen-containing dicarbonyl compound or an amino acid derivative compound.

2. The etching solution composition described in claim 1, wherein the organic acid compound consists of at least one of acetic acid and citric acid.

3. The etching solution composition described in claim 1, which is for etching a three-layer laminate film consisting of the first transparent conductive layer, the metal layer, and a second transparent conductive layer covering the metal layer.

4. The etching solution composition according to claim 1, wherein the transparent conductive layer comprises at least one of ITO, IZO, ZnO, In 2 O 3 , IGO, and AZO.

5. A method for manufacturing a display device including a display area and a non-display area, forming a thin film transistor on the substrate in the display area; forming a planarization layer on the thin film transistor; forming an electrode layer on the planarization layer; and etching the electrode layer with an etchant composition to form a pixel electrode. The etching solution composition comprises: 8% to 15% by weight of nitric acid; 2.5% to 8% by weight of a sulfonic acid compound; 6% to 14% by weight of a sulfate compound; 40% to 55% by weight of an organic acid compound; 0.01% to 0.06% by weight of a metal or metal salt; 28% to 30% by weight of water; the sulfonic acid compound comprises at least one of methanesulfonic acid, ethanesulfonic acid, and propanesulfonic acid; the sulfate compound comprises at least one of potassium hydrogen sulfate, sodium hydrogen sulfate, and ammonium hydrogen sulfate; the organic acid compound is at least one of acetic acid, citric acid, glycolic acid, malonic acid, lactic acid, and tartaric acid; the metal or metal salt is at least one of ferric nitrate, ferric sulfate, and copper; the weight percent ratio of the sulfate compound to the organic acid compound is 1:4 to 1:5; the electrode layer includes a first transparent conductive layer made of a metal oxide and a metal layer containing silver (Ag) covering the first transparent conductive layer from above, and these are etched with the etching solution composition; The concentration of silver (Ag) dissolved in the etching solution is maintained at 1,000 ppm or less, The method for manufacturing a display device, wherein the etching solution composition does not contain a nitrogen-containing dicarbonyl compound or an amino acid derivative compound.

6. A method for manufacturing a display device as described in Claim 5, wherein the organic acid compound consists of at least one of acetic acid and citric acid.

7. A method for manufacturing a display device as described in claim 5, wherein the electrode layer includes a second transparent conductive layer covering the metal layer.

8. The method for manufacturing a display device according to claim 7, wherein the first and second transparent conductive layers are made of at least one of ITO, IZO, ZnO, In 2 O 3 , IGO, and AZO.

9. Before etching with the etching solution, 8. The method for manufacturing a display device according to claim 7, wherein the etching of the second transparent conductive layer is carried out in advance with a second etching solution containing 8.1% by weight to 9.9% by weight of phosphoric acid or a phosphate.

10. forming a wiring layer in the non-display area; The method for manufacturing a display device according to claim 5 , wherein the electrode layer is etched with the etching solution composition while the wiring layer is exposed.

11. The method for manufacturing a display device according to claim 10 , wherein the wiring layer includes a first layer containing a second metal, a second layer containing a third metal, and a third layer containing the second metal.

12. The method for manufacturing a display device according to claim 10 , wherein the second metal includes titanium, and the third metal includes aluminum.

13. the thin film transistor includes a semiconductor layer, a gate electrode, a source electrode, and a drain electrode; The method of manufacturing a display device according to claim 10 , wherein the wiring layer contains the same material as the source electrode or the drain electrode.

14. The method of claim 5 , further comprising forming an intermediate layer on the pixel electrode, and forming a counter electrode on the intermediate layer.

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