Organic Light Emitting Diode Display

Abstract

An organic light emitting diode display includes: a substrate; a TFT on the substrate; a planarization layer on the TFT; a pixel electrode on the planarization layer, wherein the pixel electrode includes an upper layer and a lower layer comprising a transparent conductive oxide and an intermediate layer comprising silver; an etch stop layer on the pixel electrode, wherein an upper surface of the pixel electrode is exposed by the etch stop layer; an insulator on the etch stop layer, wherein an upper surface of the pixel electrode is exposed by the insulator; an organic emission layer on an upper surface of the pixel electrode, wherein an upper surface of the pixel electrode is exposed by the etch stop layer and the insulator; and a common electrode on the organic emission layer and the insulator, wherein the etch stop layer covers an edge and a side surface of the pixel electrode.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the priority benefit of Korean Patent Application No. 10-2019-0101063 filed on August 19, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to an organic light emitting diode display and a method of manufacturing the same, and more particularly to an organic light emitting diode display including a spacer made of an inorganic material and a method of manufacturing the same. Background Art

[0004] Since an organic light emitting diode (OLED) display emits visible light, an organic light emitting diode (OLED) display operates without a backlight. Therefore, it can display a deep black level and can be thinner and lighter than a liquid crystal display (LCD) device. Further, an OLED display has high quality characteristics, such as low power consumption, high brightness, high response speed, etc.

[0005] In an OLED display, a pixel may include a thin film transistor and an OLED, the thin film transistor may be protected by a planarization layer, and the OLED may be divided by spacers. Typically, the planarization layer and the spacers are made of organic materials, such as polyimide or polyamide.

[0006] However, when the organic material is exposed to sunlight for a long time, the organic material generates gas, such as carbon or oxygen, thereby degrading the OLED. Summary of the invention

[0007] An exemplary embodiment of the present invention provides an organic light emitting diode display, which includes: a substrate; a thin film transistor disposed on the substrate; a planarization layer disposed on the thin film transistor; a pixel electrode disposed on the planarization layer, wherein the pixel electrode includes an upper layer and a lower layer including a transparent conductive oxide and an intermediate layer including silver; an etch stop layer disposed on the pixel electrode, wherein an upper surface of the pixel electrode is exposed by the etch stop layer; an insulator disposed on the etch stop layer, wherein an upper surface of the pixel electrode is exposed by the insulator; an organic emission layer disposed on an upper surface of the pixel electrode in an area where an upper surface of the pixel electrode is exposed by the etch stop layer and the insulator; and a common electrode disposed on the organic emission layer and the insulator, wherein the etch stop layer covers an edge and a side surface of the pixel electrode.

[0008] The spacer may include an inorganic material.

[0009] The upper and lower layers of the pixel electrode may include polyindium tin oxide or indium tin oxide.

[0010] The thickness of the upper layer of the pixel electrode can be to

[0011] The etch stop layer may include a compound having low reactivity with the fluorine-based gas.

[0012] The etch stop layer may include indium zinc oxide.

[0013] The planarization layer may include polyimide, polyamide, acrylic resin, benzocyclobutene, or phenolic resin.

[0014] The thin film transistor may include a semiconductor layer, a gate electrode, a source electrode, and a drain electrode, and the drain electrode may be electrically connected to the pixel electrode.

[0015] An exemplary embodiment of the present invention provides an organic light emitting diode display, which includes: a substrate; a thin film transistor disposed on the substrate; a planarization layer disposed on the thin film transistor; a pixel electrode disposed on the planarization layer, wherein the pixel electrode includes an upper layer, an intermediate layer, and a lower layer; an etch stop layer disposed on the pixel electrode to expose an upper surface of the pixel electrode; an insulator disposed on the etch stop layer to expose an upper surface of the pixel electrode; an organic emission layer disposed on the upper surface of the pixel electrode, wherein the upper surface of the pixel electrode is exposed by the etch stop layer and the insulator; and a common electrode disposed on the organic emission layer and the insulator, wherein the intermediate layer of the pixel electrode includes silver, and the etch stop layer is disposed at an edge of the upper surface of the pixel electrode.

[0016] The upper and lower layers of the pixel electrode may include polyindium tin oxide or indium tin oxide.

[0017] The spacer may include an inorganic material.

[0018] The etch stop layer may include a compound having low reactivity with the fluorine-based gas.

[0019] The etch stop layer may include a material having a higher etch rate than that of the pixel electrode.

[0020] The thin film transistor may include a semiconductor layer, a gate electrode, a source electrode, and a drain electrode, and the drain electrode is electrically connected to the pixel electrode.

[0021] An exemplary embodiment of the present invention provides a method for manufacturing an organic light emitting diode display, the method comprising: receiving a substrate on which a planarization layer is disposed on a thin film transistor; forming a pixel electrode material layer on the planarization layer, the pixel electrode material layer comprising an upper material layer, an intermediate material layer comprising silver, and a lower material layer; forming an etch stop material layer comprising a compound having low reactivity with a fluorine-based gas on the upper material layer; forming an etch stop layer by first patterning the etch stop material layer; forming a pixel electrode comprising an upper layer, an intermediate layer, and a lower layer by patterning the pixel electrode material layer; forming an inorganic material layer for an insulator on the etch stop layer; forming an insulator by patterning the inorganic material layer for the insulator to expose the upper surface of the etch stop layer; forming an etch stop layer by second patterning the etch stop layer to expose the upper surface of the pixel electrode; forming an organic emission layer on the exposed portion of the upper surface of the pixel electrode; and forming a common electrode on the organic emission layer and the insulator.

[0022] The upper and lower layers of the pixel electrode may include polyindium tin oxide or indium tin oxide.

[0023] The formation of the spacers can be performed by dry etching.

[0024] An etch stop layer may be formed at an edge of the pixel electrode.

[0025] The formation of the etch stop layer may be performed by wet etching.

[0026] The etch stop layer may include a material having a higher etch rate than that of the pixel electrode.

[0027] An exemplary embodiment of the present invention provides an organic light emitting diode display, which includes: a substrate; a thin film transistor disposed on the substrate; a planarization layer disposed on the thin film transistor; a pixel electrode disposed on the planarization layer, wherein the pixel electrode includes a first layer, a second layer, and a third layer stacked in sequence, wherein the first layer and the third layer include a transparent conductive oxide, and the second layer includes silver; an etch stop layer disposed on an upper surface of the pixel electrode; an insulator disposed on the etch stop layer; an organic emission layer disposed on a portion of the upper surface of the pixel electrode adjacent to the etch stop layer and the insulator; and a common electrode disposed on the organic emission layer and the insulator, wherein the etch stop layer covers an edge of the pixel electrode.

[0028] The etch stop layer may cover side surfaces of the pixel electrode.

[0029] The spacer may include an inorganic material.

[0030] An organic emission layer may be formed in a space between the spacer and the etch stop layer.

[0031] The etch stop layer may directly contact the planarization layer.

[0032] The organic emission layer may directly contact the etch stop layer and the spacer. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic cross-sectional view of an organic light emitting diode display according to an exemplary embodiment of the present invention is illustrated.

[0034] Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 A cross-sectional view for describing a method of manufacturing an organic light emitting diode display according to an exemplary embodiment of the present invention is illustrated.

[0035] Fig. 9 A schematic cross-sectional view of an organic light emitting diode display according to another exemplary embodiment of the present invention is illustrated.

[0036] Fig.10 , Fig.11 , Fig.12 , Fig.13 , Fig.14 , Fig.15 , Fig.16 and Fig.17 A cross-sectional view for describing a method of manufacturing an organic light emitting diode display according to another exemplary embodiment of the present invention is illustrated. DETAILED DESCRIPTION

[0037] Hereinafter, exemplary embodiments of the present invention will be described more fully with reference to the accompanying drawings. As those skilled in the art will appreciate, the described embodiments may be modified in various different ways, and therefore, should not be limited to the embodiments set forth herein.

[0038] The same reference numbers may refer to the same or similar elements throughout the specification.

[0039] In the drawings, the thickness of layers, films, panels, regions, etc., may be exaggerated for clarity.

[0040] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present.

[0041] Further, in the specification, the phrase “in a plan view” may refer to a case where an object portion is viewed from above, and the phrase “in a cross-sectional view” may refer to a case where a cross section taken by vertically cutting the object portion is viewed from the side.

[0042] Below, we will refer to Figure 1 An organic light emitting diode display according to an exemplary embodiment of the present invention is described.

[0043] Figure 1 A schematic cross-sectional view of an organic light emitting diode display according to an exemplary embodiment of the present invention is illustrated.

[0044] refer to Figure 1 , the organic light emitting diode display according to the present exemplary embodiment may include a substrate 100, a buffer layer 110, a semiconductor layer 121, a gate insulating layer 130, a gate electrode 140, an interlayer insulating layer 150, a source electrode 161, a drain electrode 162, a planarization layer 180, a pixel electrode 190, an etch stop layer 210, an organic emission layer 350, a spacer 370, and a common electrode 270. Herein, the pixel electrode 190, the organic emission layer 350, and the common electrode 270 constitute a light emitting diode OLED.

[0045] The substrate 100 may be made of glass, plastic, or polyimide (PI).

[0046] The buffer layer 110 is disposed on the substrate 100. The buffer layer 110 is used to planarize the surface of the substrate 100 and block the penetration of impurities, and may include silicon oxide (SiO x ) or silicon nitride (SiN x ).

[0047] The semiconductor layer 121 is disposed on the buffer layer 110. The semiconductor layer 121 may be formed of an oxide semiconductor and may include a channel region, a source region, and a drain region divided according to where or whether impurities are doped. The channel region is a region in which impurities are not doped, and the source region and the drain region are regions in which impurities, such as boron (B) or phosphorus (P), are doped.

[0048] The gate insulating layer 130 is disposed on the substrate 100 to cover the semiconductor layer 121 and the buffer layer 110. The gate insulating layer 130 is formed of an inorganic insulating layer and may include silicon oxide (SiO x ) or silicon nitride (SiN x ).

[0049] The gate electrode 140 is disposed on the gate insulating layer 130. The gate electrode 140 may be formed of a metal material, and may include aluminum (Al), molybdenum (Mo), copper (Cu), or the like.

[0050] The interlayer insulating layer 150 is disposed on the substrate 100 to cover the gate electrode 140 and the gate insulating layer 130. The interlayer insulating layer 150 may be made of silicon oxide (SiO x ) or silicon nitride (SiN x) is formed as an inorganic insulating layer.

[0051] The openings 62 and 61 for exposing the source region and the drain region of the semiconductor layer 121 are formed in the interlayer insulating layer 150 and the gate insulating layer 130. The source electrode 161 and the drain electrode 162 disposed on the interlayer insulating layer 150 are connected to the source region and the drain region of the semiconductor layer 121 through the openings 62 and 61, respectively. Accordingly, the semiconductor layer 121, the gate electrode 140, the source electrode 161, and the drain electrode 162 constitute a thin film transistor (TFT).

[0052] The planarization layer 180 is disposed on the source electrode 161 and the drain electrode 162. The planarization layer 180 is disposed on the substrate 100 to cover the source electrode 161, the drain electrode 162, and the interlayer insulating layer 150. The planarization layer 180, which is used to planarize the surface of the substrate 100 including the TFT, may be formed of an organic insulating layer including one or more materials of polyimide, polyamide, acrylic resin, benzocyclobutene, and phenolic resin.

[0053] The pixel electrode 190 is disposed on the planarization layer 180. The pixel electrode 190 has a multi-layer structure including a transparent conductive oxide film, a metal material, and a transparent conductive oxide film.

[0054] The pixel electrode 190 according to the present exemplary embodiment includes an upper layer 191 made of a transparent conductive oxide film, a lower layer 193 made of a transparent conductive oxide film, and an intermediate layer 192 made of a metal material. The upper layer 191 may be made of a transparent conductive material to transmit light generated from the organic light emitting diode OLED, and the intermediate layer 192 and the lower layer 193 may function as a reflective layer. The upper layer 191 may have to or or less, the intermediate layer 192 may have to The thickness of the lower layer 193 may be to Thickness.

[0055] The transparent conductive oxide film may include at least one of indium tin oxide (ITO), poly ITO, indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), and indium tin zinc oxide (ITZO), and the metal material may include at least one of silver (Ag), molybdenum (Mo), copper (Cu), gold (Au), and aluminum (Al). The upper layer 191 of the pixel electrode 190 according to the present exemplary embodiment includes ITO or poly ITO, the middle layer 192 includes silver (Ag), and the lower layer 193 may include ITO or poly ITO. However, in some exemplary embodiments of the present invention, the upper layer 191 and the lower layer 193 may include various transparent conductive oxides, and the middle layer 192 may include various metal materials.

[0056] An opening 81 exposing the drain electrode 162 is formed in the planarization layer 180, and the drain electrode 162 and the pixel electrode 190 are connected through the opening 81. For example, the lower layer 193 of the pixel electrode 190 is connected to the drain electrode 162 through the opening 81.

[0057] The etch stop layer 210 is disposed on the pixel electrode 190 and the planarization layer 180. For example, the etch stop layer 210 is disposed to cover the edge and side surface of the pixel electrode 190 to expose a portion of the upper surface of the pixel electrode 190. For example, a portion of the upper surface of the pixel electrode 190 may be exposed through a space between the etch stop layers 210 disposed on opposite edges of the upper surface of the pixel electrode 190. The etch stop layer 210 may have a thickness of about to Thickness.

[0058] The etch stop layer 210 may be formed to cover the edge and side surface of the pixel electrode 190, thereby preventing the dry etching gas from reacting with the silver (Ag) of the pixel electrode 190 and protecting the pixel electrode 190. Figure 6 and Fig.14 The characteristics of the etch stop layer 210 will be described in detail in the dry etching process for forming the spacer 370 in FIG.

[0059] The etch stop layer 210 may include a compound having low reactivity with a fluorine (F)-based gas. For example, the etch stop layer 210 may include a compound such as indium zinc oxide (IZO), indium gallium zinc oxide, ZrCl 4 , ZrBr 4 , HfCl 4 , HfBr 4 、HgCl 2 , HgBr 2 、Al 2 Cl 6 、Al 2 Br 6 、(GaCl 3 )2 , GaBr 3 , YBr 2 or FeBr 6 , or a compound including Li, Na, Ka, Rb, Cs, Be, Mg, Ca, Sr, Ba, Sc, La, Mn, Co, Rh, Ni, Cu, Ag, Au, Zn, Cd, In, Ti, or Bi. The etch stop layer 210 may include Ga 2 O 3 、ZrO 3 、BaO、Li 2 O.La 2 O 3 、Nd 2 O 3 , BeO, Y 2 O 3 , CaO, Sc 2 O 3 、MgO、Sm 2 O 3 、Al 2 O 3 , UO 2 , B 2 O 3 、Na 2 O 2 and Nb 2 O 5 Only one of the materials is indium zinc oxide (IZO).

[0060] The spacer 370 is disposed on the etch stop layer 210. The spacer 370 is disposed to cover the edge and side surface of the etch stop layer 210 and to cover the planarization layer 180 so that a portion of the upper surface of the pixel electrode 190 is exposed. The spacer 370 may completely overlap the etch stop layer 210. The spacer 370 may divide the formation position of the organic emission layer 350 so that the organic emission layer 350 may be formed at the exposed portion of the upper surface of the pixel electrode 190.

[0061] According to the present exemplary embodiment, the spacer 370 is made of a material including silicon nitride (SiN x The spacer 370 is made of an inorganic material to block the gas (for example, gas including carbon (C), oxygen (O)) generated in the planarization layer 180 made of an organic material when the display device is exposed to sunlight for a long time. 2 ) and carbon monoxide (CO)) are introduced into the organic emission layer 350. Accordingly, the spacer 370 made of the inorganic material can prevent the OLED from being degraded.

[0062] The organic emission layer 350 is disposed in the opening defined by the spacer 370. Figure 1In FIG. 3 , the organic emission layer 350 is illustrated as a single layer, but it is understood that auxiliary layers, such as an electron injection layer, an electron transport layer, a hole transport layer, or a hole injection layer may also be included above and below the organic emission layer 350 .

[0063] The common electrode 270 is disposed on the spacer 370 and the organic emission layer 350. The common electrode 270 may be formed of a transparent conductive layer including indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), or the like.

[0064] Below, we will refer to Figures 2 to 8 A method of manufacturing an organic light emitting diode display according to an exemplary embodiment of the present invention is described.

[0065] Figures 2 to 8 A cross-sectional view for describing a method of manufacturing an organic light emitting diode display according to an exemplary embodiment of the present invention is illustrated.

[0066] refer to Figure 2 , the pixel electrode 190 (including the upper layer 191, the middle layer 192 and the lower layer 193), the TFT and the planarization layer 180 are disposed on the substrate 100, and the etch stop material layer 210' is formed on the pixel electrode 190 and the planarization layer 180. For example, the etch stop material layer 210' is directly formed on the pixel electrode 190 and the planarization layer 180.

[0067] The upper layer 191 of the pixel electrode 190 includes ITO or poly-ITO, the intermediate layer 192 of the pixel electrode 190 includes silver (Ag), and the lower layer 193 of the pixel electrode 190 includes ITO or poly-ITO. According to an exemplary embodiment of the present invention, the upper layer 191 and the lower layer 193 may be formed of various transparent conductive oxides, and the intermediate layer 192 may be formed of various metal materials.

[0068] For example, the etching stop material layer 210' may include a compound having low reactivity with a fluorine (F)-based gas, such as indium zinc oxide (IZO), indium gallium zinc oxide, ZrCl 4 , ZrBr 4 , HfCl 4 , HfBr 4 、HgCl 2 , HgBr 2 、Al 2 Cl 6 、Al 2 Br 6 、(GaCl 3 ) 2 , GaBr 3 , YBr 2 or FeBr 6or a compound including Li, Na, Ka, Rb, Cs, Be, Mg, Ca, Sr, Ba, Sc, La, Mn, Co, Rh, Ni, Cu, Ag, Au, Zn, Cd, In, Ti, or Bi. The etch stop material layer 210' may include Ga 2 O 3 、ZrO 3 、BaO、Li 2 O.La 2 O 3 、Nd 2 O 3 , BeO, Y 2 O 3 , CaO, Sc 2 O 3 、MgO、Sm 2 O 3 、Al 2 O 3 , UO 2 , B 2 O 3 、Na 2 O 2 and Nb 2 O 5 The etch stop material layer 210 ′ may be formed into the etch stop layer 210 through an etching process.

[0069] refer to Figure 3 , a photoresist (PR) pattern is formed on the etch stop material layer 210 ′.

[0070] When viewed in a direction perpendicular to the substrate 100, a photoresist (PR) pattern is formed over a region wider than the region covered by the pixel electrode 190, and the etch stop material layer 210' is first patterned by a photolithography process, etc. This first patterning includes patterning opposite ends of the etch stop material layer 210' by wet etching.

[0071] refer to Figure 4 , the photoresist (PR) pattern is removed, and the etch stop layer 210 is formed to cover both the upper surface and the side surface of the pixel electrode 190. In other words, the etch stop layer 210 completely overlaps the pixel electrode 190.

[0072] The lower layer 193 of the pixel electrode 190 contacts the upper surface of the planarization layer 180. In the organic light emitting diode display formed subsequently, the portion where the pixel electrode 190 and the planarization layer 180 contact each other may affect the electrical characteristics and light emitting characteristics of the organic light emitting diode display. In order to prevent this, in the present exemplary embodiment, the etch stop layer 210 may be first patterned, followed by a heat treatment process to convert the upper layer 191 and the lower layer 193 of the pixel electrode 190 into a poly ITO layer. In this case, the adhesive properties of the portion where the planarization layer 180 and the pixel electrode 190 contact each other may be improved.

[0073] refer to Figure 5 , an inorganic material layer 370 ′ for a spacer 370 is formed on the etch stop layer 210 and the planarization layer 180 .

[0074] The inorganic material layer 370' may be made of silicon nitride (SiN x ) etc. The spacer 370 formed thereafter includes an inorganic material to prevent the gas generated in the planarization layer 180 made of an organic material (for example, a gas including carbon (C), oxygen (O 2 ) and carbon monoxide (CO)) are introduced into the organic emission layer 350 and cause the OLED to deteriorate.

[0075] refer to Figure 6 A photoresist (PR) pattern is formed on the inorganic material layer 370 ′ for the spacer 370 . The photoresist (PR) pattern is formed at a position overlapping an edge portion of the etch stop layer 210 .

[0076] The spacer 370 is formed by dry etching the inorganic material layer 370' for the spacer 370 depending on the photoresist (PR) pattern. This dry etching process may be performed in a vacuum chamber and may use a dry etching gas such as sulfur hexafluoride (SF 6 ), nitrogen trifluoride (NF 3 ) or argon (Ar).

[0077] In the organic light emitting diode display according to the comparative example not including the etching stop layer 210 of the present invention, since the upper layer of the pixel electrode 190 is formed to have to In this case, when the particles or the like are exposed to the dry etching gas, the silver (Ag) in the intermediate layer of the pixel electrode 190 reacts with the dry etching gas to form silver oxide (Ag 2 O) or silver fluoride (AgF), and silver oxide (Ag 2O) or silver fluoride (AgF) or the like is included in the intermediate layer. Therefore, the electrical characteristics and light emitting characteristics of the organic light emitting diode display of the comparative example are deteriorated.

[0078] However, since the pixel electrode 190 according to the present exemplary embodiment is covered by the etch stop layer 210, the pixel electrode 190 is not affected by the dry etching gas. In addition, since the etch stop layer 210 is formed of a compound having low reactivity with the dry etching gas, the etch stop layer 210 is not affected by the dry etching process.

[0079] Therefore, in the present exemplary embodiment, by including the etch stop layer 210 , it is possible to prevent damage to the pixel electrode 190 in the dry etching process of forming the spacer 370 , and it is possible to prevent electrical characteristics and light emitting characteristics of the organic light emitting diode display from being degraded.

[0080] refer to Figure 7 , a spacer 370 is formed in the organic light emitting diode display to expose a portion of the upper surface of the etch stop layer 210 .

[0081] Thereafter, wet etching is performed to pattern the etching stop layer 210 for the second time. The etching stop layer 210 is patterned to expose a portion of the upper surface of the pixel electrode 190. Since the etching stop layer 210 includes a material having an etching selectivity higher than that of the pixel electrode 190, only a portion of the upper surface of the etching stop layer 210 may be etched by the etchant. Figure 4 After the step of , since the pixel electrode 190 including poly ITO is also formed of a material having a lower etch selectivity than the etch stop layer 210 through the thermal treatment process, only the etch stop layer 210 is etched by the wet etching process.

[0082] As can be seen from Table 1 below, the pixel electrode 190 is not etched in the wet etching process.

[0083] Table 1 shows the etching rates of metal materials at 45°C.

[0084] (Table 1)

[0085]

[0086] Referring to Table 1, in the wet etching process using etchant A at 45° C., IGZO, IZO, and amorphous ITO (a-ITO) are partially etched, but poly ITO and Ag maintain an etching rate of 0. In other words, according to the pixel electrode 190 of the present exemplary embodiment, poly ITO is included in the upper layer 191 and the lower layer 193 and silver (Ag) is included in the intermediate layer 192, thereby preventing the etching of the pixel electrode 190.

[0087] refer to Figure 8 , because the etch stop layer 210 is etched, the organic emission layer 350 is disposed on the exposed upper surface of the pixel electrode 190 , and the common electrode 270 is disposed on the organic emission layer 350 and the spacer 370 .

[0088] exist Figure 7 In the process of etching the etch stop layer 210, the edge of the etch stop layer 210 is etched to protrude less than the edge of the spacer 370. In other words, the edge of the spacer 370 extends beyond the etch stop layer 210 to the area where the organic emission layer 350 is formed. The distance d from one edge of the spacer 370 to one end of the etch stop layer 210 may be 0.2μm. In this case, because the edge of the spacer 370 is formed to protrude more than the edge of the etch stop layer 210, the organic emission layer 350 can be deposited flatly.

[0089] Below, we will refer to Fig. 9 An organic light emitting diode display according to another exemplary embodiment of the present invention is described.

[0090] Fig. 9 A schematic cross-sectional view of an organic light emitting diode display according to another exemplary embodiment of the present invention is illustrated.

[0091] refer to Fig. 9 , the organic light emitting diode display according to the present exemplary embodiment may include a substrate 100, a buffer layer 110, a semiconductor layer 121, a gate insulating layer 130, a gate electrode 140, an interlayer insulating layer 150, a source electrode 161, a drain electrode 162, a planarization layer 180, a pixel electrode 190, an etch stop layer 210, an organic emission layer 350, a spacer 370, and a common electrode 270. Herein, the pixel electrode 190, the organic emission layer 350, and the common electrode 270 constitute an OLED.

[0092] Fig. 9 The structure and Figure 1 Much of the structure of the organic light emitting diode display described in is similar. For example, Fig. 9 Organic light-emitting diode displays and Figure 1 The organic light emitting diode display of FIG. 1 is different in the formation position of the etch stop layer 210 , and therefore, the following description will focus on the etch stop layer 210 .

[0093] The etch stop layer 210 is disposed at the edge of the pixel electrode 190 except for the exposed portion of the upper surface of the pixel electrode 190. In other words, the end of the pixel electrode 190 and the end of the etch stop layer 210 may be located on the same surface. The etch stop layer 210 may have a thickness of about 100 mm. to Thickness.

[0094] The etching surface of the etching stop layer 210 may be formed to have a boundary consistent with the etching surfaces of the upper layer 191, the intermediate layer 192, and the lower layer 193 of the pixel electrode 190. In addition, the etching surface of the etching stop layer 210 may be formed to be located inside the boundary of the etching surface of the pixel electrode 190, so that the etching surface of the etching stop layer 210 is inconsistent with the etching surfaces of the upper layer 191, the intermediate layer 192, and the lower layer 193 of the pixel electrode 190.

[0095] The etching stop layer 210 may include a compound having low reactivity with a fluorine (F)-based gas. For example, the etching stop layer 210 may include a compound such as indium zinc oxide, indium gallium zinc oxide, ZrCl 4 , ZrBr 4 , HfCl 4 , HfBr 4 、HgCl 2 , HgBr 2 、Al 2 Cl 6 、Al 2 Br 6 、(GaCl 3 ) 2 , GaBr 3 , YBr 2 or FeBr 6 ; or a compound including Li, Na, Ka, Rb, Cs, Be, Mg, Ca, Sr, Ba, Sc, La, Mn, Co, Rh, Ni, Cu, Ag, Au, Zn, Cd, In, Ti, or Bi. The etch stop layer 210 may include Ga 2 O 3 、ZrO 3 、BaO、Li 2 O.La 2 O 3 、Nd 2 O 3 , BeO, Y 2 O 3 , CaO, Sc 2 O 3 、MgO、Sm 2 O 3 、Al 2 O 3 , UO 2 , B 2 O 3 、Na 2 O 2 and Nb 2 O 5Only one of the materials is indium zinc oxide (IZO).

[0096] Therefore, the etch stop layer 210 may be disposed at the edge of the pixel electrode 190 to include a compound having low reactivity with a fluorine (F)-based gas, thereby preventing the dry etching gas from reacting with silver (Ag) of the pixel electrode 190 and protecting the pixel electrode 190 during the dry etching process.

[0097] Below, we will refer to Figures 10 to 17 A method of manufacturing an organic light emitting diode display according to another exemplary embodiment of the present invention is described.

[0098] Figures 10 to 17 A cross-sectional view for describing a method of manufacturing an organic light emitting diode display according to another exemplary embodiment of the present invention is illustrated.

[0099] refer to Fig.10 , the thin film transistor and the planarization layer 180 are disposed on the substrate 100 , and the pixel electrode material layer 190 ′ and the etch stop material layer 210 ′ are disposed on the planarization layer 180 .

[0100] The upper material layer 191' of the pixel electrode material layer 190' includes ITO or poly-ITO, the intermediate material layer 192' of the pixel electrode material layer 190' includes silver (Ag), and the lower material layer 193' of the pixel electrode material layer 190' includes ITO or poly-ITO. According to an exemplary embodiment of the present invention, the upper material layer 191' and the lower material layer 193' may be formed of various transparent conductive oxides, and the intermediate material layer 192' may be formed of various metal materials.

[0101] For example, the etching stop material layer 210' may include a compound having low reactivity with a fluorine (F)-based gas, such as indium zinc oxide, indium gallium zinc oxide, ZrCl 4 , ZrBr 4 , HfCl 4 , HfBr 4 、HgCl 2 , HgBr 2 、Al 2 Cl 6 、Al 2 Br 6 、(GaCl 3 ) 2 , GaBr 3 , YBr 2 or FeBr 6or a compound including Li, Na, Ka, Rb, Cs, Be, Mg, Ca, Sr, Ba, Sc, La, Mn, Co, Rh, Ni, Cu, Ag, Au, Zn, Cd, In, Ti, or Bi. The etch stop material layer 210' may include Ga 2 O 3 、ZrO 3 、BaO、Li 2 O.La 2 O 3 、Nd 2 O 3 , BeO, Y 2 O 3 , CaO, Sc 2 O 3 、MgO、Sm 2 O 3 、Al 2 O 3 , UO 2 , B 2 O 3 、Na 2 O 2 and Nb 2 O 5 The etch stop material layer 210 ′ may be formed into the etch stop layer 210 through an etching process.

[0102] Through the etching process, the upper material layer 191 ′, the middle material layer 192 ′ and the lower material layer 193 ′ may form a pixel electrode 190 , and through the etching process, the etching stop material layer 210 ′ may form an etching stop layer 210 .

[0103] refer to Fig.11 The etch stop material layer 210 ′ is patterned to form the etch stop layer 210 , and a photoresist (PR) pattern for patterning the pixel electrode 190 is disposed on the etch stop layer 210 .

[0104] It should be understood that a photoresist (PR) pattern is formed on the etch stop material layer 210 ′, and then, the etch stop layer 210 may be formed through a wet etching process.

[0105] refer to Fig.12 , the pixel electrode 190 is patterned by a photoresist (PR) pattern. Accordingly, the upper layer 191 of the pixel electrode 190 may include indium tin oxide (ITO), the middle layer 192 of the pixel electrode 190 may include silver (Ag), and the lower layer 193 of the pixel electrode 190 may include indium tin oxide (ITO).

[0106] According to an exemplary embodiment of the present invention, when the upper layer 191, the intermediate layer 192 and the lower layer 193 of the pixel electrode 190 are etched simultaneously, they may be formed so that the boundaries of the etching surfaces of the respective layers are consistent with each other. In other words, the boundaries of the etching surfaces of the respective layers may form the edges of the pixel electrode 190. When one layer is etched more than another layer, an undercut may be formed in the etching surface. However, because there is no large difference in the etching degree of each layer, the pixel electrode 190 may eventually be formed to have a boundary that is almost similar to the etching surface. In other words, the boundaries (e.g., edges) of the etching surfaces of the respective layers may be adjacent to each other.

[0107] In addition, the etching surface of the etching stop layer 210 can be formed to have a boundary consistent with the etching surfaces of the upper layer 191, the middle layer 192 and the lower layer 193 of the pixel electrode 190, or the etching surface of the etching stop layer 210 can be formed to be located inside the boundary of the etching surface of the pixel electrode 190.

[0108] refer to Fig.13 , the photoresist (PR) pattern is removed, and the patterned pixel electrode 190 and the etch stop layer 210 are disposed on the planarization layer 180 .

[0109] The etch stop layer 210 is formed such that its lower surface has the same size and area as those of the upper surface of the pixel electrode 190, and an end of the etch stop layer 210 is formed on the same plane as that of the end of the pixel electrode 190. For example, the etch stop layer 210 is formed on the upper layer 191 of the pixel electrode 190.

[0110] The lower layer 193 of the pixel electrode 190 contacts the upper surface of the planarization layer 180. In a subsequent organic light emitting diode display, the portion where the pixel electrode 190 and the planarization layer 180 contact each other may affect the electrical characteristics and light emitting characteristics of the organic light emitting diode display. To prevent this, in the present exemplary embodiment, the etch stop layer 210 may be first patterned, followed by a heat treatment process, to convert the upper layer 191 and the lower layer 193 of the pixel electrode 190 into a poly ITO layer. Therefore, the adhesive property of the portion where the planarization layer 180 and the pixel electrode 190 contact each other may be improved.

[0111] refer to Fig.14 An inorganic material layer 370′ for a spacer 370 is formed on the etch stop layer 210 and the planarization layer 180, and a photoresist (PR) pattern is formed on the inorganic material layer 370′ for the spacer 370. The photoresist (PR) pattern is formed at a position overlapping an edge portion of the etch stop layer 210.

[0112] Depending on the photoresist (PR) pattern, the spacer 370 is formed by dry etching the inorganic material layer 370' for the spacer 370. This dry etching process may be performed in a vacuum chamber, and a dry etching gas such as sulfur hexafluoride (SF 6 ), nitrogen trifluoride (NF 3 ) or argon (Ar).

[0113] In the organic light emitting diode display according to the comparative example not including the etching stop layer 210, since the upper layer of the pixel electrode 190 is formed to have to In this case, when the particles or the like are exposed to the dry etching gas, the silver (Ag) in the intermediate layer of the pixel electrode 190 reacts with the dry etching gas to form silver oxide (Ag 2 O) or silver fluoride (AgF), and thus, silver oxide (Ag 2 O) or silver fluoride (AgF) or the like is included in the intermediate layer. Therefore, the electrical characteristics and light emitting characteristics of the organic light emitting diode display of the comparative example are deteriorated.

[0114] However, since the etch stop layer 210 is disposed at the upper portion of the edge of the pixel electrode 190 according to the present exemplary embodiment, the pixel electrode 190 is not affected by the dry etching gas. In addition, since the etch stop layer 210 is formed of a compound having low reactivity with the dry etching gas, the etch stop layer 210 is not affected by the dry etching process.

[0115] Therefore, in the present exemplary embodiment, by including the etch stop layer 210 , it is possible to prevent damage to the pixel electrode 190 in the dry etching process of forming the spacer 370 , and it is possible to prevent electrical characteristics and light emitting characteristics of the organic light emitting diode display from being degraded.

[0116] refer to Fig.15 The spacer 370 is formed to expose a portion of the upper surface of the etch stop layer 210 in the organic light emitting diode display. Thereafter, a wet etching process is performed to pattern the etch stop layer 210.

[0117] refer to Fig.16 , the etch stop layer 210 is patterned a second time by a wet etching process to expose a portion of the upper surface of the pixel electrode 190 .

[0118] Since the etching stop layer 210 includes a material having a higher etching selectivity than the pixel electrode 190, only a portion of the upper surface of the etching stop layer 210 may be etched by the etchant. Fig.13, since the pixel electrode 190 including poly ITO is also formed of a material having a lower etch selectivity than the etch stop layer 210 through the thermal treatment process, only the etch stop layer 210 is etched through the wet etching process.

[0119] In addition, Fig.15 In the process of etching the etch stop layer 210, the edge of the etch stop layer 210 is etched so that the edge of the etch stop layer 210 protrudes less than the edge of the spacer 370. In other words, the edge of the spacer 370 extends beyond the edge of the etch stop layer 210. The distance d from one edge of the spacer 370 to one edge (or end) of the etch stop layer 210 may be 0.2μm. In this case, the organic emission layer 350 may be evenly deposited on the upper surface of the pixel electrode 190.

[0120] refer to Fig.17 , because the etch stop layer 210 is etched, the organic emission layer 350 is disposed on the exposed upper surface of the pixel electrode 190 , and the common electrode 270 is disposed on the organic emission layer 350 and the spacer 370 .

[0121] Therefore, in the present exemplary embodiment, by including the etch stop layer 210 , it is possible to prevent damage to the pixel electrode 190 in the dry etching process of forming the spacer 370 , and it is possible to prevent electrical characteristics and light emitting characteristics of the organic light emitting diode display from being degraded.

[0122] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various modifications may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. An organic light emitting diode display, comprising: substrate; A thin film transistor disposed on the substrate; a planarization layer disposed on the thin film transistor; a pixel electrode disposed on the planarization layer, wherein the pixel electrode comprises an upper layer and a lower layer comprising a transparent conductive oxide and an intermediate layer comprising silver; an etch stop layer disposed on the pixel electrode, wherein an upper surface of the pixel electrode is exposed by the etch stop layer; a spacer obtained by dry etching and disposed on the etching stop layer, wherein the upper surface of the pixel electrode is exposed by the spacer; an organic emission layer disposed on the upper surface of the pixel electrode in a region where the upper surface of the pixel electrode is exposed by the etch stop layer and the spacer; as well as A common electrode is disposed on the organic emission layer and the spacer, wherein the etching stop layer covers the edge and side surface of the pixel electrode, The dry etching gas used in the dry etching process includes sulfur hexafluoride or nitrogen trifluoride, and The etch stop layer includes a compound containing indium zinc oxide (IZO), indium gallium zinc oxide, ZrCl4, ZrBr4, HfCl4, HfBr4, HgCl2, HgBr2, Al2Cl6, Al2Br6, (GaCl3)2, GaBr3, YBr2, FeBr6, Li, Na, Ka, Rb, Cs, Be, Mg, Ca, Sr, Ba, Sc, La, Mn, Co, Rh, Ni, Cu, Ag, Au, Zn, Cd, In, Ti or Bi.

2. The organic light emitting diode display according to claim 1, wherein The spacer includes an inorganic material.

3. The organic light emitting diode display according to claim 1, wherein The upper layer and the lower layer of the pixel electrode include polyindium tin oxide or indium tin oxide.

4. The organic light emitting diode display according to claim 1, wherein The thickness of the upper layer of the pixel electrode is to 5. The organic light emitting diode display according to claim 1, wherein The etch stop layer includes indium zinc oxide.

6. An organic light emitting diode display, comprising: substrate; A thin film transistor disposed on the substrate; a planarization layer disposed on the thin film transistor; A pixel electrode disposed on the planarization layer, wherein the pixel electrode comprises an upper layer, a middle layer and a lower layer; an etch stop layer disposed on the pixel electrode to expose an upper surface of the pixel electrode; a spacer obtained by dry etching and disposed on the etching stop layer to expose the upper surface of the pixel electrode; an organic emission layer disposed on the upper surface of the pixel electrode, wherein the upper surface of the pixel electrode is exposed by the etch stop layer and the spacer; as well as A common electrode is disposed on the organic emission layer and the spacer, wherein the intermediate layer of the pixel electrode comprises silver, and The etching stop layer is disposed at an edge of the upper surface of the pixel electrode, The dry etching gas used in the dry etching process includes sulfur hexafluoride or nitrogen trifluoride, and The etch stop layer includes a compound containing indium zinc oxide (IZO), indium gallium zinc oxide, ZrCl4, ZrBr4, HfCl4, HfBr4, HgCl2, HgBr2, Al2Cl6, Al2Br6, (GaCl3)2, GaBr3, YBr2, FeBr6, Li, Na, Ka, Rb, Cs, Be, Mg, Ca, Sr, Ba, Sc, La, Mn, Co, Rh, Ni, Cu, Ag, Au, Zn, Cd, In, Ti or Bi.

7. The organic light emitting diode display according to claim 6, wherein The upper layer and the lower layer of the pixel electrode include polyindium tin oxide or indium tin oxide.

8. The organic light emitting diode display according to claim 6, wherein The etch stop layer includes a material having a higher etch rate than an etch rate of the pixel electrode.

Images