forming a gate line and a data line on a first substrate;

forming a thin film transistor at a crossing point of the gate line and the data line;

forming a pixel electrode and a common electrode on the first substrate;

forming a passivation film on the pixel electrode and the common electrode;

performing an orientation treatment of the passivation film by irradiating an ion beam on the passivation film;

forming a black matrix layer on a second substrate;

forming a color filter layer on the black matrix layer;

forming an overcoat layer on the color filter layer; and

performing an orientation treatment of the overcoat layer by irradiating an ion beam on the passivation film,

wherein the pixel electrode, the common electrode and the gate line are arranged in a zigzag configuration,

wherein irradiating the ion beam comprises: generating a plasma from an ion beam source, forming an ion beam from the plasma, accelerating the ion beam by applying an electric field to an ion beam acceleration medium; and irradiating the ion beam on one of the first and second substrates at a predetermined angle.