Forming the light emitting element may include forming a first electrode electrically connected to the source electrode or the drain electrode, forming an emission layer on the first electrode, and forming a second electrode on the emission layer.

Another embodiment of the invention provides a method of manufacturing a display device including forming a polysilicon layer on a substrate, patterning the polysilicon layer to form a polysilicon pattern including a main body, and a first protrusion and a second protrusion each protruding upward from an upper surface of the main body, forming a gate insulation layer on the polysilicon pattern, forming a gate electrode on the gate insulation layer, partially implanting ions into the polysilicon pattern to form an active layer, forming an insulation interlayer on the gate electrode, forming a source contact hole and a drain contact hole each passing through the insulation interlayer and the gate insulation layer and respectively overlapping the first protrusion and the second protrusion, forming a source electrode and a drain electrode respectively filling the source contact hole and the drain contact hole, and forming a light emitting element electrically connected to the source electrode or the drain electrode.

Forming the polysilicon layer may include forming an amorphous silicon layer on the substrate, cleaning the amorphous silicon layer with hydrofluoric acid, rinsing the amorphous silicon layer with hydrogenated deionized water, and irradiating the amorphous silicon layer with a laser beam.

A thickness of the main body may be in a range of about 250 ? to about 450 ?.

Each of a thickness of the first protrusion and a thickness of the second protrusion may be greater than 0 ? and less than about 220 ?.