Abstract: A radiation imager is disclosed that is resistant to degradation due to moisture by either contact pad corrosion, guard ring corrosion or by photodiode leakage. A contact pad of a large area imager is disclosed that is formed into three distinct and electrically connected regions. The resulting structure of the contact pad regions forms reliable contact that is resistant to corrosion damage. Also disclosed is a data line of an imager, or a display, the resistance of which is reduced by patterning an aluminum (Al) line on top of a transistor island structure, with the formed data line preferably being encapsulated. In addition, a guard ring having first and second regions and photosensitive element are disclosed. The second region comprises an electrical contact between ITO and underlying metal and a second tier which acts as a moisture barrier and is preferably disposed at the corner of the guard ring and separated from the contact pads of the imager in such a manner as to minimize corrosion.

Abstract: An imager includes a substrate, a light-sensitive imaging array on the substrate, a scintillator over the array, and a cover over the scintillator sealed to the substrate. An edge of the array is situated close to an edge of the substrate relative to other edges of the array and substrate. A U-shaped end cap is sealed to and covers an edge of the cover, the edge of the substrate and a portion of each of the cover and substrate inward from their respective edges.

Abstract: A radiation imager is disclosed that is resistant to degradation due to moisture by either contact pad corrosion, guard ring corrosion or by photodiode leakage. A contact pad of a large area imager is disclosed that is formed into three distinct and electrically connected regions. The resulting structure of the contact pad regions forms reliable contact that is resistant to corrosion damage. Also disclosed is a data line of an imager, or a display, the resistance of which is reduced by patterning an aluminum (Al) line on top of a transistor island structure, with the formed data line preferably being encapsulated. In addition, a guard ring having first and second regions and photosensitive element are disclosed. The second region comprises an electrical contact between ITO and underlying metal and a second tier which acts as a moisture barrier and is preferably disposed at the corner of the guard ring and separated from the contact pads of the imager in such a manner as to minimize corrosion.

Abstract: A detector (20) for high voltage x-rays includes a plurality of sensor elements (22) with each sensor element being aligned along a respective focal axis (25) with respect to a high voltage x-ray source (24). A fiber optic scintillator (34) is optically coupled to each of said sensor elements and is disposed to receive incident x-ray radiation passing from the object to be imaged. Optical fibers of the scintillator are positioned such that their optical axes are perpendicular to incident x-rays. Each sensor element has a length along the focal axis sufficiently long for the fibers to absorb substantially all incident x-rays. Each sensor element comprises an array of amorphous silicon photosensors disposed to detect light generated by the scintillator.

Abstract: A radiation imager is disclosed that is resistant to degradation due to moisture by either contact pad corrosion, guard ring corrosion or by photodiode leakage. A contact pad of a large area imager is disclosed that is formed into three distinct and electrically connected regions. The resulting structure of the contact pad regions forms reliable contact that is resistant to corrosion damage. Also disclosed is a data line of an imager, or a display, the resistance of which is reduced by patterning an aluminum (Al) line on top of a transistor island structure, with the formed data line preferably being encapsulated. In addition, a guard ring having first and second regions and photosensitive element are disclosed. The second region comprises an electrical contact between ITO and underlying metal and a second tier which acts as a moisture barrier and is preferably disposed at the corner of the guard ring and separated from the contact pads of the imager in such a manner as to minimize corrosion.

Abstract: A radiation imager includes a photosensor barrier layer disposed between an amorphous silicon photosensor array and the scintillator. The barrier layer includes two strata, the first stratum being silicon oxide disposed over the upper conductive layer of the photosensor array and the second stratum is silicon nitride that is disposed over the first stratum. The photosensor barrier layer has a shape that substantially conforms to the the shape of the underlying upper conductive layer and has a maximum thickness of about 3 microns. The silicon oxide and silicon nitride are deposited in a vapor deposition process at less than about 250.degree. C. using tetraethoxysilane (TEOS) as the silicon source gas.

Abstract: An imager array data line repair structure for use in high performance imager arrays includes a first and a second plurality of address lines that are disposed in respective layers with an intermediate layer having at least one insulative material disposed therebetween. The imager device further includes at least one integral address line repair segment that is disposed in the same layer as the first address lines and that is electrically isolated from the first address lines; the integral address line repair segment is disposed so as to underlie a repair portion of the second address line, with the intermediate layer disposed therebetween, and has a width substantially the same as the overlying second address line.

Abstract: A process for repairing an electronic army wafer assembly having a short circuit between two non-insulative layers separated by a dielectric layer includes the step of selectively ablating one of the non-insulative layers so as to electrically isolate the situs of the short circuit while maintaining the electrical integrity of the underlying non-insulative layer intact. A laser beam is directed onto the non-insulative layer and scanned in a selected pattern to isolate the situs of the short circuit; the laser is further controlled such that a selected energy density is delivered to the surface to be ablated such that the underlying non-insulative layer is not damaged.

Abstract: A solid state radiation imager includes a photosensor array having a plurality of pixels disposed on a substrate, each pixel having a respective photosensor coupled to a thin film transistor (TFT). The photosensor array further includes an opaque passivation layer that is disposed over non-photodiode areas of the photosensor array, including the TFT and address lines in the array. The opaque passivation layer has an absorbance that is greater than 1, and typically that is greater than 2. The opaque passivation layer further is typically made of a thermally stable polymer mixed with a light absorbing material such as an organic dye (e.g., Sudan Black B), carbon black, or graphite.

Abstract: A radiation imager includes a photosensor array having a plurality of individually addressable pixels, each pixel having a photosensor island and an associated thin film transistor (TFT) disposed to selectively electrically couple the photosensor island to a predetermined address line. In each pixel a single common passivation layer is disposed over the TFT and the photosensor island such that the passivation layer is adjacent to both the outer surfaces of the TFT and portions of the photosensor island. In a method of fabricating a photosensor array as described above, after depositon of a source-drain metal layer, the layer is left unpatterned until after the photosensor island has been formed. In the formation of the photosensor island the source-drain metal layer serves as an etch stop to protect the TFT. Following formation of the photosensor island, the source-drain metal layer is patterned to form source and drain electrodes and fabrication of the TFT is completed.

Abstract: Repair lines in an imager device include protective layers disposed over steps in the repair lines where the repair lines extend over underlying components in the imager array. The protective layers each include a layer of polyimide to provide protection for the step portions of the conductive repair line from etchants and the like to which the conductive line is exposed during fabrication processes for the imager array. The protective layers are disposed over the steps of a conductive line in a repair crossover region so as to provide a repair area free from the protective material of the protective layers disposed thereon in the repair crossover region where the conductive repair line is disposed in vertical alignment with an underlying address line.

Abstract: A radiation imager includes a photosensor barrier layer disposed between an amorphous silicon photosensor array and the scintillator. The barrier layer includes two strata, the first stratum being silicon oxide disposed over the upper conductive layer of the photosensor array and the second stratum is silicon nitride that is disposed over the first stratum. The photosensor barrier layer has a shape that substantially conforms to the the shape of the underlying upper conductive layer and has a maximum thickness of about 3 microns. The silicon oxide and silicon nitride are deposited in a vapor deposition process at less than about 250.degree. C. using tetraethoxysilane (TEOS) as the silicon source gas.

Abstract: A solid state radiation imager pixel having a thin film transistor (TFT) coupled to a photodiode in which the photodiode and the TFT each comprise a common dielectric layer, that is, a single dielectric layer that extends across the pixel and that has a gate dielectric layer portion and a photodiode body passivation portion. The common dielectric layer comprises a monolithic dielectric material such as silicon nitride or silicon oxide. Further, the bottom electrode of the photosensor body and the gate electrode are each disposed on a common surface of the substrate and comprise the same conductive material, the conductive material having been deposited on the pixel in the same deposition process. The source and drain electrodes and the common contact electrode for the photodiode each comprises the same source/drain metal conductive material, the conductive material having been deposited on the pixel in the same deposition process.

Abstract: A computed tomography (CT) imager includes a scintillator and a photosensor array optically coupled to the scintillator through an optical coupling layer. The photosensor array includes a plurality of photosensitive devices disposed in a block so as to receive incident light from the scintillator through a first surface of the block; each photosensitive device forms a pixel in the array, and each pixel further has a fully photoactive region in which the quantum efficiency of the photosensor is greater than about 65%. The optical coupling layer further includes a pixel boundary light barrier that is made of light absorptive material disposed in the optical coupling layer overlying the areas on the photosensor array first surface between respective fully photoactive regions of the photosensitive devices.

Abstract: A radiation imager includes a photosensor array having a plurality of individually addressable pixels, each pixel having a photosensor island and an associated thin film transistor (TFT) disposed to selectively electrically couple the photosensor island to a predetermined address line. In each pixel a single common passivation layer is disposed over the TFT and the photosensor island such that the passivation layer is adjacent to both the outer surfaces of the TFT and portions of the photosensor island. In a method of fabricating a photosensor array as described above, after depositon of a source-drain metal layer, the layer is left unpatterned until after the photosensor island has been formed. In the formation of the photosensor island the source-drain metal layer serves as an etch stop to protect the TFT. Following formation of the photosensor island, the source-drain metal layer is patterned to form source and drain electrodes and fabrication of the TFT is completed.

Abstract: A self-aligned, inverted, thin film field effect transistor is produced by patterning the gate electrode to have tapered edges followed by conformal deposition of subsequent layers of the device structure up through a support layer followed by deposition of a subordinate layer such as the source/drain metallization) on the support layer. The subordinate layer itself may be a planarization or non-conformal layer or may have a subsequent non-conformal planarization layer disposed thereon. Thereafter, the structure is non-selectively etched (preferably reactive ion etched) until the support layer is exposed by the creation of an aperture in the subordinate layer in alignment with raised portions of the reference layer while leaving the subordinate layer present on other parts of the structure. Thereafter, the remainder of the device is fabricated with the source and drain electrodes self-aligned with respect to the gate conductor using a selective etch method.

Abstract: A thin film transistor (TFT) having reduced end leakage is fabricated by: forming a gate electrode on a substrate; forming a TFT body disposed over the gate electrode, the TFT body comprising an intrinsic semiconductor material layer, a channel plug disposed on the intrinsic semiconductor material layer over the gate electrode, a doped semiconductor material layer on the intrinsic semiconductor material and the sidewalls of the channel plug, and a source/drain metallization layer; selectively etching the source/drain metallization layer to form an address connection line and a pixel connection line to a respective source electrode tip and drain electrode tip, selectively etching the channel plug to remove the portion of the sidewalls not adjoining the source and electrode tips that had been in contact with the doped semiconductor layer; removing the doped semiconductor layer portion not underlying the address connection line, the pixel connection line, and the source and drain electrode tips; and removing the

Abstract: Indium-tin oxide is selective etched relative to silicon, molybdenum, aluminum, titanium, silicon oxide and silicon nitride using an organic radical and oxygen containing plasma which contains sufficient oxygen to prevent deposition of undesirable films on non-etching portions of the component being etched and on the reactor surfaces. The plasma lacks halogenated gases. A minimum differential etch rate of 8:1 of indium-tin oxide to silicon results with the other materials etching slower than silicon or not at all.

Abstract: A collimator for use in an imaging system with a radiation point source has a plurality of channels formed therein along longitudinal axes aligned with selected orientation angles that correspond to the direct beam path from the radiation source to the radiation detectors. The collimator comprises a photosensitive material coated with a radiation absorbent material. The cross-sectional shape of the channels corresponds to the cross-sectional shape of the radiation detecting area of the detector element adjoining the channel, and the sidewalls of the channel are smooth along their length.

Abstract: A collimator for use in an imaging system with a radiation point source is formed from a plurality of collimator plates stacked together. Passages in each collimator plate in conjunction with the respective passages in adjoining plates form a plurality of channels through the collimator. The channel longitudinal axes are aligned with selected orientation angles that correspond to the direct beam path from the radiation source to the radiation detectors. The collimator plates are made up of patterned sheets of radiation absorbent material or alternatively comprise patterned photosensitive material substrates coated with a radiation absorbent material. The cross-sectional shape of each channel corresponds to the cross-sectional shape of the radiation detecting area of the detector element adjoining the channel.