Patent ID: 7807519

Claim:
A method of forming a thin film transistor, comprising: forming a gate over a substrate, wherein the gate is a single-layered molybdenum-niobium alloy nitride layer; forming a gate insulating layer over the substrate to cover the gate; forming a semiconductor layer over the gate insulating layer above the gate; and forming a source/drain over the semiconductor layer, wherein the step of forming the source/drain comprises: forming a molybdenum-niobium alloy layer over the gate insulating layer to cover the semiconductor layer; performing a nitridation step for the molybdenum-niobium alloy layer to form a molybdenum-niobium alloy nitride layer, wherein the nitridation step is performed after forming the molybdenum-niobium alloy layer or when depositing the molybdenum-niobium alloy layer; and patterning the molybdenum-niobium alloy nitride layer to form the source/drain.