The second semiconductor pattern 321 of the second thin film transistor 320 may be formed on the second buffer layer 114. The second semiconductor pattern 321 may be disposed in the display area DA while overlapping with the first storage capacitor 140. The second semiconductor pattern 321 may be an oxide semiconductor pattern made of an oxide semiconductor. The second thin film transistor 320 may include the second semiconductor pattern 321, a second gate electrode 324, a second source electrode 322, and a second drain electrode 323. Alternatively, the second source electrode 322 may become a drain electrode, and the second drain electrode 323 may become a source electrode.
The second semiconductor pattern 321 may include a second channel region 321C, at which a channel may be formed during driving of the second thin film transistor 320, and a second source region 321S and a second drain region 321D respectively disposed at opposite sides of the second channel region 321C. The second source region 321S may be a portion of the second semiconductor pattern 321 connected to the second source electrode 322, and the second drain region 321D may be a portion of the second semiconductor pattern 321 connected to the second drain electrode 323.