Display device and method of making the same

A display device and a method for manufacturing the same are provided to perform acid treatment on a semiconductor layer, thereby improving the characteristic of a thin film transistor. A semiconductor layer(121) and an ohmic contact layer(122) are sequentially formed on an insulating substrate(110). Source and drain electrodes(131,132) are formed on the ohmic contact layer, and are distanced from each other. A portion of the ohmic contact layer, which is not covered by the source electrode and the drain electrode, is removed to expose the semiconductor layer between the source electrode and the drain electrode. Acid treatment is performed on the exposed portion of the semiconductor layer. An insulating layer(141) is formed on the semiconductor layer after the acid treatment.