摘要:
A CT detector includes a pixel having a single photodiode and multiple charge storage devices that are alternately stored and read out. The photodiode is a frontlit diode with a pair of capacitors that alternately store charge generated during data acquisition. Multiple pixels are connected to a single readout amplifier. Charge is continuously acquired from each photodiode and stored on the charge storage devices, but such readout is from a single charge storage device at a time. As such, each charge storage device is read out independently, but the charge storage devices are connected to a common readout channel or port.
摘要:
A method of repairing an open circuit defect in a damaged address line in a thin film electronic imager device includes the steps of forming a repair area on the device so as to expose the open-circuit defect in the damaged address line and then depositing a conductive material to form a second conductive component and to coincidentally form a repair shunt in the repair area so as to electrically bridge the defect. The step of forming the repair area includes the steps of ablating dielectric material disposed over the first conductive component in the repair area, and etching the repair area so as to remove dielectric material disposed over the defect in the address line in the repair area such that the surface of the address line conductive material is exposed but is not contaminated by the removal of the overlying dielectric material. A layer of photoresist is deposited over the imager device prior to forming the repair area, such that the photoresist layer is patterned during the ablating step and serves as a mask during the etch step.
摘要:
A flat panel radiation imaging device that exhibits reduced capacitive coupling between pixel photodiodes and readout data lines, and thus in operation has reduced phantom images and image artifacts, includes a ground plane electrode that is disposed between the substrate and the plurality of pixels arranged in an imaging array pattern. The ground plane electrode is a conductive material layer that is disposed in a continuous sheet underlying the imaging array pattern; alternatively, the ground plane is a patterned sheet of conductive material having data line cutout areas disposed so that no ground plane conductive material underlies or is closer than a lateral set off distance from data lines in the imaging array pattern. A patterned ground plane further may include pixel electrode cutout sections disposed such that ground plane conductive material underlies pixel electrodes in the imaging array pattern only by a selected overlap distance around the boundaries of the pixel electrode.
摘要:
In the fabrication of thin-film field-effect transistors, a dielectric island is first formed over a gate and between locations where source and drain contacts are to be deposited. A dielectric cap with an overhanging brim is formed on the island. A layer of SD metal which will form the source-drain contacts is next deposited. Because of the overhang, the SD metal does not coat the entire cap, but leaves part of the cap remaining exposed and attackable by an etchant. Application of an etchant etches away the island and the cap, thereby lifting off the SD metal coated on the cap, leaving the fully-formed source and drain contacts in place, separated by the extent of the island.
摘要:
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 now-exposed portion of the intrinsic semiconductor layer material that had been in contact with the doped semiconductor material.
摘要:
A dual dielectric structure is employed in the fabrication of thin film field effect transistors in a matrix addressed liquid display to provide improved transistor device characteristics and also to provide both electricial and chemical isolation for material employed in the gate metallization layer. In particular, the use of a layer of silicon oxide over the gate metallization layer is not only consistent with providing the desired electrical and chemical isolation, but also with providing redundant gate metallization material to be employed beneath source or data lines for electrical circuit redundancy. Gate line redundancy is also possible. The electrical and chemical isolation provided by the dual dielectric layer reduces the possibilities of short circuits occurring in the display. The absence of short circuits together with the improved redundancy characteristics significantly increase manufacturing yield. As display sizes increase, the yield problem becomes more and more significant, generally growing as the square of the diagonal measurement of the screen. The structure in the present invention also significantly reduces gate leakage current. In the process and structure of the present invention, gate electrode material is separated from semiconductor material by the aforementioned dual dielectric, typically comprising layers of silicon oxide disposed beneath a layer of silicon nitride which is, in turn, disposed beneath the active amorphous silicon semiconductor material.
摘要:
A method for photolithographically forming a mask includes the steps of: forming an island structure of opaque material on a principal surface of a transparent substrate; depositing at least one layer of transparent material on the principal substrate surface and over the island structure; depositing a layer of photoresist material over the at least one transparent layer; exposing a back-side substrate surface, opposite to the principal substrate surface, to UV light to cause exposure of at least a portion of the photoresist, corresponding substantially to an area outside of a shadow of the island structure; reflecting at least a portion of UV light back into the photoresist layer, by depositing a non-specular layer over the photoresist layer before UV exposure, to expose another portion of the photoresist layer a selected overlap distance within the island structure shadow; and removing the exposed photoresist portion to form a mask which is aligned with the island structure and narrower than the island structure by the selected overlap distance on each side thereof.
摘要:
An amorphous silicon thin film FET is doped and structured to be particularly useful for use in liquid crystal display circuits. In particular, critical FET dimensions are provided along with doping levels and locations which permit optimal reduction of source to gate capacitance, while at the same time, preventing the occurrence of large contact voltage drops. Critical dimensions include active channel length, source-gate overlap, and amorphous silicon thickness. A critical relationship is established amongst these parameters and amorphous silicon doping levels.
摘要:
A method for storing data in an archival memory semiconductor target by inducing damage to the semiconductor lattice at selected ones of a plurality of storage sites arranged as a two-dimensional array upon a surface of the target. Ions are accelerated and collimated as a beam to impinge upon a target surface to induce the damage to a controlled depth, whereby subsequent illumination of a damaged data site by an electron beam will allow the beam-produced electron-hole pairs to recombine within the damaged area to prevent increased current flow and read a binary zero bit, while hole migrations through a target depletion region will cause increased current flow, at an undamaged data site, to indicate a binary one data bit.
摘要:
A detector module for a CT imaging system includes a scintillator to convert x-rays to optical photons. The scintillator is optically coupled to a solid-state photomultiplier with internal gain to receive the optical photons and convert them into a corresponding electrical signal output.