A substrate including a first signal line and a first electrode disposed on the substrate, an oxide semiconductor layer pattern overlapping the first electrode, an insulating layer disposed between the first electrode and the oxide semiconductor layer pattern, a second signal line intersecting the first signal line, a second electrode electrically connected to the oxide semiconductor layer pattern, a third electrode electrically connected to the oxide semiconductor layer pattern and spaced apart from the second electrode, and an insulator comprising a first portion disposed between the first signal line and the second signal line, and at least partially overlapping with both of the first signal line and the second signal line.