A display device and a manufacturing method thereof are provided. The display device includes a substrate, first and second signal lines formed on the substrate, a first thin film transistor connected to the first and second signal lines., a gate driver and a data driver connected to the first signal line and the second signal line, respectively, and a second thin film transistor formed in at least one of the gate driver and the data driver The first thin film transistor and the second thin film transistor include a first semiconductor and a second semiconductor, respectively, and the first semiconductor and the second semiconductor are formed at the different layers from each other.