Tft substrate, scanning antenna provided with tft substrate and method for producing tft substrate

A TFT substrate including a dielectric substrate, a plurality of antenna unit regions arranged on the dielectric substrate, each of the plurality of antenna unit regions including a TFT and a patch electrode connected to a drain electrode of the TFT, a transmission and/or reception region including the plurality of antenna unit regions, and a non-transmission and/or reception region located in a region other than the transmission and/or reception region, the TFT substrate comprising:

• a gate metal layer supported by the dielectric substrate, and including a gate electrode of the TFT, a gate bus line connected to the gate electrode, and the patch electrode;
• a gate insulating layer formed on the gate metal layer and including a first opening at least reaching the patch electrode;
• a source metal layer formed on the gate insulating layer, and including a source electrode of the TFT, the drain electrode, a drain extending section extending from the drain electrode, and a source bus line connected to the source electrode;
• an interlayer insulating layer formed on the source metal layer, and including a second opening overlapping the first opening when viewed from a normal direction of the dielectric substrate and a third opening at least reaching the drain extending section;
• and
• a conductive layer formed on the interlayer insulating layer and including a patch drain connection section,
• wherein the patch drain connection section is in contact with the patch electrode within the first opening and in contact with the drain extending section within the third opening.