Active matrix substrate, method for manufacturing active matrix substrate, and liquid crystal display device with touch sensor using active matrix substrate

An active matrix substrate comprising:

• a substrate;
• a thin film transistor supported on the substrate, the thin film transistor including a gate electrode, a semiconductor layer, a source electrode and a drain electrode;
• an interlayer insulating layer covering the thin film transistor;
• a pixel electrode arranged above the interlayer insulating layer;
• a common electrode arranged between the pixel electrode and the interlayer insulating layer;
• a first dielectric layer arranged between the common electrode and the pixel electrode;
• a common wiring line arranged between the interlayer insulating layer and the pixel electrode, and formed of a first conductive film;
• a second dielectric layer arranged between the interlayer insulating layer and the common electrode;
• a pixel contact portion electrically connecting the pixel electrode to the thin film transistor, wherein
• the semiconductor layer includes a channel region, a source region, and a drain region,
• the gate electrode overlaps the channel region,
• the source electrode is electrically connected to the source region,
• the drain electrode is electrically connected to the drain region,
• the pixel contact portion includes
• the drain electrode of the thin film transistor,
• the Interlayer insulating layer including a lower opening exposing a portion of the drain electrode,
• a connection electrode electrically connected to the drain electrode in the lower opening,
• the first dielectric layer including a first upper opening exposing a portion of the connection electrode,
• the pixel electrode electrically connected to the connection electrode in the upper opening, and
• the common wiring line is arranged between the interlayer insulating layer and the common electrode.

A manufacturing method of an active matrix substrate including a display region including a pixel area and a non-display region located around the display region, and including a thin film transistor and a pixel electrode arranged in the pixel area, the manufacturing method comprising:

• (A) forming the thin film transistor on a substrate, the thin film transistor including a gate electrode, a semiconductor layer, a source electrode and a drain electrode;
• (B) forming an interlayer insulating layer that covers the thin film transistor, the interlayer insulating layer including a lower opening that exposes a portion of the drain electrode of the thin film transistor;
• (C) forming a first metal layer on the interlayer insulating layer, the first metal layer including a common wiring line and a connection electrode, the connection electrode being in contact with a portion of the drain electrode in the lower opening;
• (D) forming a first dielectric layer that covers the first metal layer and the interlayer insulating layer, the first dielectric layer including a first opening that exposes a portion of the common wiring line;
• (E) forming a common electrode on the first dielectric layer, the common electrode being connected to the common wiring line in the first opening;
• (F) forming a second dielectric layer that covers the common electrode and the first dielectric layer;
• (G) forming an upper opening in the first dielectric layer and the second dielectric layer that exposes a portion of the connection electrode;
• and
• (H) forming the pixel electrode on the second dielectric layer and in the upper opening, the pixel electrode being in contact with the connection electrode in the upper opening.