A thin film transistor substrate includes a base substrate, an active pattern, a gate insulation pattern and a gate electrode. The active pattern is disposed on the base substrate. The active pattern includes a source electrode, a drain electrode, and a channel disposed between the source electrode and the drain electrode. The gate insulation pattern and the gate electrode overlap with the channel. The gate insulation pattern is disposed between the channel and the gate electrode. The source electrode and the drain electrode each include a fluorine deposition layer.