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.A method of fabricating an imager array includes, for each pixel in the array, the steps of depositing a first conductive layer on a substrate, forming a gate electrode and a photosensor bottom electrode from the first conductive layer, forming a photosensor body disposed on at least a portion of the photosensor bottom electrode, depositing a common dielectric layer over the gate electrode and over the photosensor body and exposed portion of the photosensor bottom electrode, and completing fabrication of the pixel TFT and the photosensor such that the TFT is electrically coupled to the respective photosensor. The portion of the common dielectric layer disposed over the gate electrode comprises the gate dielectric layer and the portion disposed over the photosensor body comprises the photosensor passivation layer.
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 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:
Solid state photodetectors having amorphous silicon photodiode bodies with sloped sidewalls allowing for deposition of high integrity conformal layers thereover are produced by etching the amorphous silicon in a mostly anisotropic etchant in a reactive ion etcher in which the pressure of the etchant is controlled. A photoresist mask having sloped sidewalls is formed over the amorphous silicon to be etched and the pressure of the etchant is selected to produce the desired slope of the sidewall in the photodetector body; at lower pressures a smaller slope is produced in the silicon and at higher pressures a steeper slope is produced in the silicon.
摘要:
A method of fabricating a thin film transistor (TFT) including the steps of forming a gate conductor on a substrate; depositing a gate dielectric layer over the gate conductor; depositing a layer of amorphous silicon over the gate dielectric layer; treating the exposed surface of the amorphous silicon with a hydrogen plasma; depositing a layer of n+ doped silicon over the treated amorphous silicon surface such that an interface is formed between the amorphous silicon and the n+ doped layer that has relatively low contact resistance; depositing a layer of source/drain metallization over the n+ doped layer; and patterning the source/drain metallization and portions of the underlying n+ doped layer to form source and drain electrodes. The TFT material layers are preferably deposited by plasma enhanced chemical vapor deposition. The hydrogen plasma treatment is advantageously used both when vacuum is maintained during the various deposition steps, and when vacuum is broken, for the purposes of patterning the amorphous silicon layer or the like, such that the amorphous silicon layer is passivated with the hydrogen plasma treatment prior to the deposition of the n+ doped layer.
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:
Solid state photodetectors having amorphous silicon photodiode bodies with sloped sidewalls allowing for deposition of high integrity conformal layers thereover are produced by etching the amorphous silicon in a mostly anisotropic etchant in a reactive ion etcher in which the pressure of the etchant is controlled. A photoresist mask having sloped sidewalls is formed over the amorphous silicon to be etched and the pressure of the etchant is selected to produce the desired slope of the sidewall in the photodetector body; at lower pressures a smaller slope is produced in the silicon and at higher pressures a steeper slope is produced in the silicon.
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 solid state array device includes a plurality of pixels with associated respective TFT switching transistors; a plurality of first address lines disposed in a first layer of the array device; a plurality of second conductive address lines disposed in a second layer of the array device, respective ones of said first and second address lines being disposed substantially perpendicular to one another in a matrix arrangement such that respective ones of the second address lines overlie respective ones of the first address lines at respective crossover regions; a TFT gate dielectric layer disposed in a channel region of each of the pixel TFTs and further being disposed over the first address lines; and a crossover region supplemental dielectric layer disposed in respective ones of the crossover regions between the first and second address lines, but disposed so as to not extend over the TFT channel regions.