An array substrate device having a color filter-on-thin film transistor (COT) structure for a liquid crystal display device includes a gate line formed on a substrate along a transverse direction, the gate line including a gate pad at one end thereof, a first insulating layer formed on the substrate to cover the gate line, the first insulating layer exposing a first portion of the gate pad, a data line formed over the first insulating layer along a longitudinal direction on the substrate, the data line defining a pixel region with the gate line and including a data pad at one end thereof, a thin film transistor formed at a crossing region of the gate and data lines, the thin film transistor including a gate electrode, a semiconductor layer, a source electrode, and a drain electrode, a black matrix overlapping the thin film transistor, the gate line, and the data line except a second portion of the drain electrode, a second insulating layer formed over an entire surface of the substrate to cover the black matrix, the second insulating layer exposing the first portion of the gate pad, a third portion of the data pad, and the pixel region, a first pixel electrode within the pixel region and contacting the second exposed portion of the drain electrode, a color filter on the first pixel electrode within the pixel region, and a second pixel electrode on the color filter and contacting the first pixel electrode.