Patent ID: 7582217

Claim:
A method of manufacturing a flat panel display device, comprising: providing a substrate; forming a first conductive layer on the substrate; patterning the first conductive layer to form a gate electrode; forming a gate insulating layer on the gate electrode; forming a semiconductor layer on the gate insulating layer corresponding to the gate electrode; forming a second conductive layer on the semiconductor layer; patterning the second conductive layer to form source/drain electrodes; forming a passivation layer over an entire surface of the substrate including the source/drain electrodes, wherein the passivation layer has a contact hole exposing a portion of the drain electrode; and forming a third conductive layer on the passivation layer to be electrically connected to the drain electrode through the contact hole; and patterning the third conductive layer to form a pixel electrode, wherein the gate electrode, the source/drain electrodes and the pixel electrode are patterned using the same etchant composition; and wherein the etchant composition comprises phosphoric acid having a concentration of about 40 to 70 wt %, nitric acid having a concentration of about 3 to 15 wt %, acetic acid having a concentration of about 5 to 35 wt %, a chlorine-based compound having a concentration of about 0.02 to 5 wt %, a nitrate-based compound having a concentration of about 0.05 to 5 wt %, a sulfate-based compound having a concentration of about 0.05 to 5 wt %, an oxidation regulator having a concentration of about 1 to 10 wt %, and a residual quantity of water.