The effects of magnetic field shape between indium tin oxide (ITO) targets on electrical characteristics of top-emission organic light emitting diodes (TOLEDs) have been investigated. When the top electrode is prepared with ITO using facing target sputtering (FTS) method, it was found that TOLEDs with ITO layers prepared in the diffused plasma mode showed much lower leakage current density (1 x 10(-5) mA/cm(2) at -6 V) than (1 x 10(-1) mA/cm(2) at -6 V) of TOLEDs prepared with ITO in the concentrated mode. Even when the ITO film itself had the identical electrical, optical, and structural properties, TOLEDs clearly exhibited different electrical properties based on the plasma mode at which the ITO film was sputtered. This suggests that there is less plasma damage from the bombardment of energetic particles in a diffused plasma mode than in a concentrated plasma mode during the FTS process. (c) 2005 The Electrochemical Society.