Patent ID: 6949468

Claim:
A method of preventing cathode break in an active matrix organic light emitting diode device through a process of rounding the corners of the source/drain terminal of a thing film transistor, the method comprising: forming a conductive layer over a substrate; and conducting an etching operation to form the source/drain pattern of the thin film transistor, where the source/drain pattern has a sloping profile at each end, and the step of forming the source/drain pattern comprising forming a patterned first photoresist layer over the conductive layer; conducting a first etching operation using the first photoresist layer as an etching mask to remove a definite thickness of the conductive layer; removing a definite thickness from the first photoresist layer to form a second photoresist layer; and conducting a second etching operation using the second photoresist layer as an etching mask to form the source/drain pattern.