Patent ID: 8377766

Claim:
A method of making a source/drain electrode and a channel of a thin film transistor, comprising: providing a substrate and sequentially forming a semiconductor layer and a metal layer on the substrate; providing a photo-mask, wherein the photo-mask comprises: a transparent substrate; a first opaque pattern and a second opaque pattern disposed on the transparent substrate, wherein the first opaque pattern comprises a first side edge and a second side edge, the second opaque pattern comprises a third side edge and a fourth side edge, and the first side edge of the first opaque pattern is disposed in opposition to the third side edge of the second opaque pattern; a transparent single slit disposed between the first side edge of the first opaque pattern and the third side edge of the second opaque pattern; and at least a translucent pattern disposed on the transparent substrate, wherein the translucent pattern is connected to the second side edge of the first opaque pattern and the translucent pattern is connected to the fourth side edge of the second opaque pattern, wherein the translucent pattern is not located between the transparent substrate and the first opaque pattern, and is not located between the transparent substrate and the second opaque pattern; forming a photoresist layer on the metal layer and using the photo-mask to perform an exposure process on the photoresist layer, wherein the first opaque pattern and the second opaque pattern of the photo-mask correspond to a first region of the photoresist layer, the transparent single slit of the photo-mask corresponds to a second region of the photoresist layer, and the translucent pattern of the photo-mask corresponds to a third region of the photoresist layer; performing a development process on the photoresist layer to remove a portion of the photoresist layer to uncover the metal layer, wherein, after the development process, a thickness of the photoresist layer of the first region is thicker than a thickness of the photoresist layer of the second region and a thickness of the photoresist layer of the third region; removing the metal layer and the semiconductor layer uncovered by the photoresist layer; performing an ashing process on the photoresist layer to reduce the thickness of the photoresist layer of the first region and removing the photoresist layer of the second region and the photoresist layer of the third region to uncover the metal layer; removing the metal layer and a portion of the semiconductor layer uncovered by the photoresist layer to define a source electrode, a drain electrode, a channel and an extension portion; and removing the photoresist layer.