摘要:
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. The single common passivation layer is then deposited over both the TFT and the photosensor island.
摘要:
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.
摘要:
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.
摘要:
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. The single common passivation layer is then deposited over both the TFT and the photosensor island.
摘要:
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. The collimator may be fabricated by forming a mask on a photosensitive collimator substrate, exposing the photosensitive substrate to light beams traveling along a path corresponding to a direct path of radiation from the radiation source to the detector elements in the assembled array, etching the collimator substrate to form channels therein along the exposed area of the substrate, and coating the substrate with a radiation absorbent material.
摘要:
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.
摘要:
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.
摘要:
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. In initial fabrication, the integral address line repair segment is electrically isolated from the overlying repair segment of the second address line; in the event a repair has been effected, the repair portion of the second address line is electrically coupled to the underlying integral address line repair segment through laser welds.
摘要:
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. A method of forming a collimator includes the steps of selectively removing material from the collimator plates to form the passages therein, and stacking the patterned collimator plates together to align them so that the respective adjacent passages form a channel aligned with respective selected orientation angles corresponding to direct paths of radiation from the radiation source to the detector elements in the assembled array.
摘要:
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. The collimator may be fabricated by forming a mask on a photosensitive collimator substrate, exposing the photosensitive substrate to light beams traveling along a path corresponding to a direct path of radiation from the radiation source to the detector elements in the assembled array, etching the collimator substrate to form channels therein along the exposed area of the substrate, and coating the substrate with a radiation absorbent material.