Organic light-emitting display device and method of manufacturing the same
An organic light-emitting display device including a substrate; at least one thin-film transistor (TFT) formed on the substrate; a planarizing layer covering the TFT; a pixel electrode, which is formed on the planarizing layer and is connected to the TFT; a protective layer surrounding an edge of the pixel electrode; a pixel defining layer (PDL), which has an overhang (OH) structure protruding more than the top surface of the protective layer, covers the protective layer and the edge of the pixel electrode, and exposes a portion of the pixel electrode surrounded by the protective layer; a counter electrode facing the pixel electrode; and an intermediate layer, which is interposed between the pixel electrode and the counter electrode and includes a light-emitting layer and at least one organic layer, where the thickness of the intermediate layer is greater than the thickness of the protective layer.
1. A method of manufacturing an organic light-emitting display device, the method comprising:
(a) providing a substrate having at least one thin-film transistor (TFT);
(b) sequentially forming a pixel electrode electrically coupling the TFT and a protective layer on the substrate;
(c) forming a pixel defining layer (PDL) to surround an edge of the protective layer and to expose a portion of the protective layer by forming an insulation layer to cover the pixel electrode and the protective layer and patterning the insulation layer;
(d) etching the protective layer to expose a portion of the pixel electrode, so that an overhang (OH) structure, in which the PDL protrudes more than the top surface of the protective layer, is formed; and
(e) forming an intermediate layer by ejecting a light-emitting layer and at least one organic layer as liquid onto the exposed pixel electrode.
2. The method of claim 1 , wherein, in operation (b), the thickness of the protective layer is at or between 100 Å and 1000 Å.
3. The method of claim 1 , wherein, in operation (b), the protective layer comprises a metal having higher etching selectivity than the pixel electrode.
4. The method of claim 3 , wherein the pixel electrode and the protective layer comprise transparent conductive oxides (TCOs).
5. The method of claim 4 , wherein each of the pixel electrode and the protective layer comprises poly indium-tin-oxide (poly ITO), amorphous ITO (a-ITO), indium gallium oxide (IGO), or aluminum zinc oxide (AZO),
the etching selectivities of which increase in the order stated, and
the protective layer comprises a material having higher etching selectivity than the pixel electrode.
6. The method of claim 1 , wherein, in operation (c), the PDL comprises an inorganic insulation layer.
7. The method of claim 6 , wherein the PDL is formed through dry-etching.
8. The method of claim 7 , wherein the PDL is etched by using plasma.
9. The method of claim 1 , wherein, in operation (d), the protective layer is formed through wet-etching.
10. The method of claim 1 , wherein, in operation (d), the protective layer is etched, such that the OH structure of the PDL protrudes to be at or between 0.2 μm and 5 μm from an edge of the protective layer.
11. The method of claim 1 , wherein, in operation (e), the overall thickness of the intermediate layer is greater than the thickness of the protective layer.
12. The method of claim 1 , wherein, in operation (e), at least one organic layer is formed between the light-emitting layer and the pixel electrode, and
the overall thickness of the organic layer is identical to or greater than the thickness of the protective layer.
13. The method of claim 1 , wherein, in operation (e), the intermediate layer is formed through inkjet printing or nozzle printing.
14. The method of claim 1 , further comprising forming a counter electrode, which is a common electrode, on the intermediate layer after operation (e).