Mask for forming a thin-film transistor, thin-film transistor substrate manufactured using the same and method of manufacturing a thin-film transistor substrate using the same

A method of manufacturing a thin film transistor substrate, comprising:

• forming a gate insulating layer, an active layer, a data metal layer and a photoresist film on a base substrate having a gate electrode to cover the gate electrode;
• exposing the photoresist film using a mask, wherein the mask includes:
• a drain mask pattern,
• a source mask pattern spaced apart from the drain mask pattern and facing the drain mask pattern, and
• a light-adjusting pattern interposed between two end portions of the source mask pattern and the drain mask pattern to form a photoresist pattern having a channel groove between the drain and source mask patterns;
• partially etching the data metal layer and the active layer using the photoresist pattern as an etching mask to form a data metal pattern and an active pattern;
• decreasing a thickness of the photoresist pattern so that the data metal pattern is exposed through the channel groove;
• and
• partially etching the data metal pattern through the channel groove to form a data line having a source electrode and a drain electrode.