Patent ID: 7713799

Claim:
A method of making a thin film transistor comprising the steps of: forming a gate electrode on a substrate; forming a gate insulating film on the substrate including the gate electrode; sequentially forming a semiconductor layer and a metal layer on the gate insulating film; forming a pattern having a step difference on the metal layer having a U-shape in cross-section by comprising the steps of a) forming a first pattern having a predetermined shape on a first printing roll using a first printing plate; b) rotating the first printing roll on the metal layer to transfer the first pattern onto the metal layer; c) forming a second pattern having different shape from the first pattern on a second printing roll using a second printing plate, wherein the second printing roll being different from the first printing roll and the second printing plate is different from the first printing plate; and d) rotating the second printing roll on the metal layer to transfer the second pattern onto the first pattern; etching the semiconductor layer and the metal layer using the pattern as a mask; and removing the pattern.