Method of making a large area imager with UV Blocking layer, and corresponding imager

摘要

This invention is related to a radiation imager (e.g. X-ray imager) including a thin film transistor (TFT) array, and method of making same. A photo-imageable insulating material having a low dielectric constant is provided in areas of overlap between electrodes and underlying TFTs, diodes, and/or address lines in order to improve the signal-to-noise ratio of the imager. The photo-imageable insulating layer acts as a negative resist in certain embodiments, so that vias are formed therein by exposing portions of the insulating layer with UV light which are to remain on the substrate, removing non-exposed areas of the insulating layer so as to form the vias or apertures in the insulating layer. In order to prevent non-uniformities from inadvertently being imaged into the photo-imageable insulating layer, an ultraviolet (UV) blocking/absorbing layer is provided. The UV blocking layer may be formed on the opposite side of the substrate from the TFTs, or alternatively may be formed as part of the gate insulating layer.