A touch screen substrate includes a base substrate, a first switching element and a first sensing element which senses infrared light. The first switching element includes a first switching gate electrode, a first active pattern disposed on the first switching gate electrode, a first switching source electrode disposed on the first active pattern and a first switching drain electrode disposed apart from the first switching source electrode. The first sensing element includes a first sensing drain electrode connected to the first switching source electrode, a first sensing source electrode disposed apart from the first sensing drain electrode, a second active pattern disposed below the first sensing drain electrode and the first sensing source electrode and including a first amorphous layer, a doped amorphous layer and a second amorphous layer, and a first sensing gate electrode disposed on the first sensing drain electrode and the first sensing source electrode.