Organic light-emitting display apparatus and method of manufacturing the same

1. An organic light-emitting display apparatus comprising:

a substrate;

a thin film transistor (TFT) on the substrate;

a pixel-defining layer (PDL) disposed on the TFT, comprising a first area having a first thickness and a second area having a second thickness greater than the first thickness, and further comprising a via hole in the first area;

a pixel electrode disposed on at least a portion of the first area of the PDL and at least a portion of the second area of the PDL, and electrically connected to the TFT via the via hole;

an intermediate layer on the pixel electrode, the intermediate layer comprising an emission layer (EML); and

an opposite electrode on the intermediate layer.

2. The organic light-emitting display apparatus of claim 1 , wherein the PDL comprises a third area, wherein the second area is formed between the first area and the third area, the third area having a third thickness greater than the first thickness and the second thickness.

3. The organic light-emitting display apparatus of claim 1 , wherein the PDL comprises a sloped area between the first area and the second area, and the pixel electrode is disposed on the first area and at least a portion of the sloped area.

4. The organic light-emitting display apparatus of claim 1 , wherein the pixel electrode fills the via hole, and is disposed on a portion of the first area.

5. The organic light-emitting display apparatus of claim 1 , wherein the TFT comprises an active layer, a gate electrode, a source electrode, and a drain electrode, a gate insulating layer disposed between the active layer and the gate electrode, and an interlayer insulating layer disposed between the gate electrode and each of the source electrode and the drain electrode, and the pixel electrode is electrically connected to at least one of the source electrode and the drain electrode.

6. The organic light-emitting display apparatus of claim 5 , wherein the PDL is directly disposed on the interlayer insulating layer and the source and drain electrodes.

7. The organic light-emitting display apparatus of claim 1 , wherein the pixel electrode includes a first transparent conductive oxide layer, a metal layer on the first transparent conductive oxide layer, and a second transparent conductive oxide layer on the metal layer.

8. The organic light-emitting display apparatus of claim 1 , wherein the opposite electrode is disposed on the first area and the second area, and the second area directly contacts the opposite electrode.

9. The organic light-emitting display apparatus of claim 1 , wherein the first area and the via hole are formed by using a halftone mask.

10. The organic light-emitting display apparatus of claim 1 , further comprising a thin film encapsulation layer on the opposite layer.

11. A method of manufacturing an organic light-emitting display apparatus, the method comprising:

forming a thin film transistor (TFT) on a substrate;

forming a pixel-defining layer (PDL) on the TFT, wherein the PDL comprises a first area having a first thickness and a second area having a second thickness greater than the first thickness, and wherein the PDL further comprises a via hole in the first area;

forming a pixel electrode on at least a portion of the first area and at least a portion of the second area, wherein the pixel electrode is electrically connected to the TFT via the via hole;

forming an intermediate layer on the pixel electrode, the intermediate layer comprising an emission layer (EML); and

forming an opposite electrode on the intermediate layer.

12. The method of claim 11 , wherein forming the PDL comprises forming the PDL on the TFT, wherein the PDL further comprises a third area, wherein the second area is disposed between the first area and the third area, said third area having a third thickness greater than the first thickness and the second thickness.

13. The method of claim 11 , wherein forming the PDL comprises forming the PDL by using a halftone mask.

14. The method of claim 11 , wherein forming the TFT comprises:

forming an active layer on the substrate;

forming a gate insulating layer on the active layer;

forming a gate electrode on the gate insulating layer with the gate electrode overlapping with a portion of the active layer;

forming a source region and a drain region on the active layer;

forming an interlayer insulating layer on the gate electrode and the gate insulating layer, wherein the interlayer insulating layer comprises contact holes at least partially exposing the source region and the drain region; and

forming a source electrode and a drain electrode on the interlayer insulating layer, wherein the source electrode and the drain electrode are electrically connected to the source region and the drain region, respectively, via the contact holes.