Thin film transistor including compound semiconductor oxide, method of manufacturing the same and flat panel display device having the same

A thin film transistor, comprising:

• a substrate;
• a gate electrode formed on the substrate;
• a gate insulating film formed on the gate electrode and the substrate;
• an activation layer formed on the gate insulating layer and insulated from the gate electrode by the gate insulating film, the activation layer comprising, a compound semiconductor oxide or zinc oxide (ZnO);
• a passivation layer formed on the activation layer, comprising an inorganic oxide comprising at least one metal comprised in the activation layer;
• and
• source and drain electrodes that contact the activation layer,
• wherein the inorganic oxide comprises gallium (Ga), indium (In), tin (Sn), zirconium (Zr), hafnium (Hf), vanadium (V), or a combination thereof.