Thin-film transistor substrate, method of manufacturing same, and organic light-emitting display apparatus including thin-film transistor substrate

A method of manufacturing a thin film transistor (TFT) substrate, the method comprising:

• forming a semiconductor layer on a substrate;
• patterning the semiconductor layer into an active layer and a lower capacitor electrode;
• forming a first insulating layer to cover the active layer and the lower capacitor electrode;
• forming a gate electrode of a TFT and a connection layer of a capacitor on the first insulating layer;
• forming a second insulating layer having an opening through which a source area and a drain area of the active layer and the connection layer are exposed;
• forming an temporary layer on the connection layer, a source electrode, and a drain electrode;
• forming a third insulating layer having an opening through which a part of the source electrode and the temporary layer are exposed;
• removing a part of the connection layer and the temporary layer;
• and
• forming a pixel electrode electrically connected to one of the source electrode and the drain electrode, and an upper capacitor electrode corresponding to the lower capacitor electrode, the pixel electrode and the upper capacitor electrode formed on the third insulating layer.