High resolution x-ray imaging using amorphous silicon flat-panel arrays

Two dimensional amorphous silicon arrays are the emerging technology for di gital medical x-ray imaging. This paper demonstrates an improved pixel desi gn compared with the current generation of imagers. The geometry of the pix el sensor has been extended from a mesa isolated structure into a continuou s layer above the readout structures of the array. This approach improves s ensitivity to visible light, and to xray illumination when coupled with a c onversion phosphor. Furthermore, this 3-dimensional geometry allows for the fabrication of the finest pitch amorphous silicon array yet manufactured, with a pixel size of 64 mu m square. A test array (512x640 pixels) has been fabricated and tested which demonstrates the success of this approach.