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

Two dimensional amorphous silicon arrays are the emerging technology for digital medical X-ray imaging. This paper demonstrates an improved pixel design compared with the current generation of imagers. The geometry of the pixel sensor has been extended from a mesa isolated structure into a continuous layer above the readout structures of the array. This approach improves sensitivity to visible light and X-ray illumination when coupled with a conversion 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 μm square. A test array (512×640 pixels) has been fabricated and tested which demonstrates the success of this approach