Patent ID: 7749826

Claim:
A method of forming wires for a poly-crystalline thin film transistor manufactured by crystallizing an amorphous silicon thin film of a semiconductor layer using a metal film for metal induced lateral crystallization (MILC), the wires forming method comprising the steps of: removing a MILC metal film used to crystallize the amorphous silicon thin film formed on a substrate; forming first and second etch-stopper layer patterns on at least part of said silicon thin film formed on the substrate, said first and second etch-stopper layer patterns corresponding to respective source and drain regions formed on the semiconductor layer; forming an interlayer insulation film on the entire surface of the substrate, said interlayer insulation film covering said first and second etch-stopper layer patterns; etching the interlayer insulation film to thereby form first and second contact holes which expose the first and second etch-stopper layer patterns of the source and drain regions; and forming a wires metal film contacting the first and second etch-stopper layer patterns exposed through the first and second contact holes, and patterning the wires metal film to thus form metal wires; wherein said first and second etch-stopper layer patterns are made of the same material as said metal wires, said material being selected from a group consisting of MoW, Mo, Al and Cu; wherein the step of forming the first and second etch-stopper layer patterns includes the following steps of: forming a photosensitive pattern on which first and second contact windows are formed in correspondence to positions where the etch-stopper layer patterns are formed; and depositing the etch-stopper layer patterns on the entire surface of the substrate and removing the photosensitive film using a lift-off method, to thereby make the first and second etch-stopper layer patterns locally contacting the semiconductor layer of the source region and the drain region via the first and second contact windows remain.