METHOD FOR MANUFACTURING THIN FILM TRANSISTOR

摘要

PURPOSE: A method for manufacturing a thin film transistor is provided to reduce the contamination of nickel metal in an LTPS(Low Temperature Polycrystalline Silicon) manufacturing process by an MILC(Metal Induced Lateral Crystallization). CONSTITUTION: A crystallization is firstly occurred at a doping region(230c) by a nickel layer formed on a highly doped amorphous silicon layer during a first annealing. In the crystallization process of the doping region, the injected dopant is simultaneously activated, so that n+ or p+ region(230c) and an LDD region(230b') in which they have substantially low resistance are completed. By a continuous lateral crystallization, crystallization is performed till a channel region(230a'). Although the nickel is removed completely, since NiSi2 is already formed at a source/drain region(230c), crystallization is performed continuously during a second annealing process, as a next process.