Method of adjusting gap between bumps in pixel region and method of manufacturing display device using the method

#This application claims priority from Korean Patent Application No. 10-2011-0050183 filed on May 26, 2011 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

#1. Field

#The present disclosure relates to a method of forming a thin-film transistor (TFT) structure, which can improve light-emitting efficiency, using laser crystallization.

#The above and other aspects and features will become more apparent by describing in detail certain embodiments with reference to the attached drawings, in which:

#FIG. 1 illustrates an embodiment wherein a gap between protrusions is adjusted by overlapping laser-irradiated regions;

#FIG. 2 illustrates an embodiment wherein a gap between protrusions is adjusted by irradiating a certain region with a laser beam having a high energy density;

#Embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will convey the scope of the invention to those skilled in the art. The same reference numbers generally indicate the same components throughout the specification. In the attached figures, the thickness of layers and regions may be exaggerated for clarity.

#Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It is noted that the use of any and all examples, or exemplary terms provided herein is intended merely to better illustrate the invention and is not a limitation on the scope of the invention unless otherwise specified.

#A bumpy structure of a pixel electrode increases a surface area of the pixel electrode, leading to an increase in a light-emitting area of the pixel electrode. When the pixel electrode has a bumpy structure, the light-emitting area of the pixel electrode is increased, at the same aperture ratio, compared with when the pixel electrode has a flat structure. From the perspective of refractive index, in a conventional organic light-emitting display device, a surface between an anode and a light-emitting element is parallel to a surface between a pixel electrode and a passivation film. In such a structure, light generated at an angle greater than a critical angle is totally reflected. Since an angle of incidence is equal to an angle of reflection, the light cannot escape the surface between the pixel electrode and the passivation film. If a bumpy structure is formed in the pixel region, an angle of reflection of the light generated at an angle greater than the critical angle may change as the light is totally reflected. Accordingly, this can increase the light extraction efficiency of the light-emitting element.