Organic light-emitting display device having a gate insulating layer with controlled dielectric constants and method of manufacturing the same

An organic light-emitting display device comprising:

• an organic light-emitting diode;
• a first transistor configured to control, in response to a voltage applied to a first node connected to a first gate electrode of the first transistor, an amount of current flowing to the organic light-emitting diode from a second node connected to a power voltage line;
• a third transistor connected between the first node and a third node, and configured to diode-connect the first transistor in response to a voltage applied to a third gate electrode of the third transistor, wherein the third node is between the first transistor and the organic light-emitting diode;
• and
• a gate insulating layer interposed between a first active region of the first transistor and the first gate electrode, and between a third active region of the third transistor and the third gate electrode,
• wherein a dielectric constant in a first portion of the gate insulating layer between the first active region and the first gate electrode is greater than a dielectric constant in a second portion of the gate insulating layer between the third active region and the third gate electrode.