Thin film transistor substrate and organic light-emitting diode (OLED) display having the same

A thin film transistor substrate for a display device, comprising:

• a substrate;
• a source electrode formed over the substrate;
• a drain electrode formed over the substrate and spaced apart from the source electrode;
• an oxide semiconductor layer that includes i) a source area at least partially overlapping the source electrode, ii) a drain area at least partially overlapping the drain electrode, and iii) a channel area formed between the source area and the drain area;
• and
• a gate electrode insulated from the oxide semiconductor layer, wherein the oxide semiconductor layer has a first width at a first end thereof and a second width at a second end opposite to the first end thereof and the first width is different from the second width,
• wherein the oxide semiconductor layer comprises at least one of indium, gallium, zinc, or tin, and
• wherein the source area of the oxide semiconductor layer comprises a plurality of portions branched from the channel area.

An organic light-emitting diode (OLED) display comprising:

• a display element;
• and
• a thin film transistor configured to drive the display element, wherein the thin film transistor comprises i) a source electrode, ii) a drain electrode spaced apart from the source electrode iii) an oxide semiconductor layer that includes a source area at least partially overlapping the source electrode, a drain area at least partially overlapping the drain electrode, and a channel area formed between the source area and the drain area, and iv) a gate electrode insulated from the oxide semiconductor layer, wherein the oxide semiconductor layer has a first width at a first end thereof and a second width at a second end opposite to the first end thereof, wherein the first width is different from the second width,
• wherein the oxide semiconductor layer has third and fourth widths respectively at first and second intermediate portions directly connected to each other, wherein the oxide semiconductor layer linearly increases in width from the first end to the first intermediate portion at a first slope and from the second intermediate portion to the second end at a second slope, wherein the oxide semiconductor layer increases in width from the first intermediate portion to the second intermediate portion at a third slope greater than the first and second slopes, and wherein the second intermediate portion extends upwardly and downwardly from the first intermediate portion.