Referring to FIGS. 18 and 19, a source contact hole CHS and a drain contact hole CHD may be formed, a source electrode SE and a drain electrode filling the source contact hole CHS and the drain contact hole CHD, respectively, may be formed, and a light emitting element EE electrically connected to the source electrode SE or the drain electrode DE may be formed. Descriptions on components of a method of manufacturing a display device according to still another embodiment described with reference to FIGS. 18 and 19, which are substantially the same as or similar to those of the method of manufacturing the display device according to an embodiment described with reference to FIGS. 1 to 14, will not be repeated.

First, as illustrated in FIG. 18, the source contact hole CHS and the drain contact hole CHD penetrating the insulation interlayer 150 and the gate insulation layer 140 may be formed. In the process of forming the source contact hole CHS and the drain contact hole CHD, the first region R1 and the second region R2 of the active layer ACT may be etched together with the insulation interlayer 150 and the gate insulation layer 140.