Abstract: A method (and resultant structure) of forming a semiconductor device, includes forming a metal-back-gate over a substrate and a metal back-gate, forming a passivation layer on the metal back-gate to prevent the metal back-gate from reacting with radical species, and providing an intermediate gluing layer between the substrate and the metal back-gate to enhance adhesion.

Abstract: Disclosed is an image sensor including one or more dummy pixels that produce a reference signal which is used to compensate for errors within the devices of the main pixel cells. In one embodiment, at least one dummy pixel is used in conjunction with other circuitry to correct for nonlinearities in the transfer characteristic of a source follower transistor within each pixel. In another embodiment, an array of dummy pixels is used to correct for leakage current within the pixels during an electronic shutter mode of operation. The two techniques can be combined whereby both threshold voltage mismatch and leakage current are compensated for.

Abstract: The present invention relates to an automatic gain control circuit in which the automatic gain control function is performed entirely in the digital domain. In an illustrative embodiment, the digital automatic gain control circuit for an image sensor having associated therewith an analog-to digital (A/D) converter for converting analog electrical signals from the image sensor to corresponding digital codes, includes a min/max detector for determining minimum and maximum electrical signal values from the digital codes of the A/D converter for each frame of image. A filter coupled to the min/max detector dampens instantaneous changes of the minimum and maximum values by filtering to provide filtered minimum and maximum values.

Abstract: A CMOS image sensor is provided in which correlated double sampling is performed entirely in the digital domain. In an exemplary embodiment, the image sensor includes a plurality of imager cells arranged in rows and columns, where the imager cells of a particular column are coupled to a column data line of that column. Each active imager cell is capable of selectively providing a first output on an associated column data line indicative of a reset level during a first sampling interval. During a second sampling interval, each active imager cell provides a signal output on the associated column data line indicative of an amount of light incident upon that imager cell. At least one analog to digital (A/D) converter is coupled to the column data lines and converts the first and signal outputs on each column data line to first and second digital codes, respectively, to complete a correlated double sampling operation. The invention eliminates the need for analog capacitors to store the reset and signal levels.

Abstract: An image sensor is described incorporating a plurality of detector cells arranged in an array where each detector cell has a MOSFET with a floating body and operable as a lateral bipolar transistor to amplify charge collected by the floating body. The invention overcomes the problem of insufficient charge being collected in detector cells formed on silicon-on-insulator (SOI) substrates due to silicon thickness and will also work in bulk silicon embodiments.

Abstract: Disclosed is an image sensor having A/D conversion circuitry coupled to column data lines of an image sensor array. The A/D conversion circuitry digitizes analog signals on the column data lines, each representing intensity of light incident upon an active imager cell. Higher resolution is provided for darker light levels than for bright light levels, such that a high resolution image is obtained with less storage data than would otherwise be required. In one embodiment, the A/D conversion circuitry includes a plurality of comparators, each having a first input coupled to one or more column data lines and a second input coupled to receive a time-varying reference signal, and a plurality of n-bit counters coupled to the comparator outputs. An n-bit to m-bit converter nonlinearly maps n-bit codes to m-bit codes and provides the m-bit codes to an m-bit D/A converter which produces the time-varying reference signal.

Abstract: Disclosed is an image sensing device having a reduced number of transistors within each imager cell as compared to prior art devices. Each imager cell includes a photosensitive element providing a photocharge responsive to incoming light, and first, second and third transistors. The first transistor is coupled to an activation line, e.g., a row select line, that carries an activation signal to a first plurality of imager cells to selectively activate cells for image data readout. This transistor transfers the photocharge towards a reference circuit node within the image cell in response to the activation signal. The second transistor is operably coupled to the first transistor, and is operative to selectively set a voltage level at the reference node. The third transistor has a control terminal coupled to the reference node, and an output terminal coupled to an output data bus common to a second plurality of image cells, e.g., a column of cells.

Abstract: Disclosed is a circuit for performing correlated double sampling entirely in the digital domain. In an exemplary embodiment, the circuit includes a plurality of comparators, each having a first input coupled to an associated data line for receiving first and second signals in first and second sampling intervals, respectively. A time varying reference signal is applied to the second input of each comparator. A plurality of up/down counters are coupled to respective ones of the comparators, and each is operable to count in a first direction during the first sampling interval and in an opposite direction during the second sampling interval. Each up/down counter is caused to stop counting when the amplitude of the variable reference signal substantially equals the amplitude of the respective first or second signal. As a result, each up/down counter provides an output representing a subtraction of one of said first or second signals from the other.

Abstract: The present invention concerns single-gate and double-gate field effect transistors having a sidewall source contact and a sidewall drain contact, and methods for making such field effect transistors. The channel of the present field effect transistors is raised with respect to the support structure underneath and the source and drain regions form an integral part of the channel.

Abstract: A photodetector array for sensing radiant energy is described incorporating photodetectors, a respective semiconductor region for holding charge and two transistors coupled in series at each pixel, and a column load transistor. An amplifier at the load transistor may provide gain while providing dynamic range compression and a reduction in signal noise due to resetting of the voltage at the semiconductor regions. The invention overcomes the problem of CMOS manufacturing of photodetector arrays and for a simplified circuit per pixel to enable denser arrays and reduced noise.

Abstract: A novel method of fabricating a double-gate MOSFET structure is disclosed. The method utilizes selective lateral epitaxial growth of silicon into a thin gap formed between two sacrificial dielectric films for accurate thickness control. The sacrificial films are then replaced by a gate material (e.g., polysilicon) such that top and bottom gates are self-aligned to each other and to the channel region. Also disclosed is a self-aligned double-gate MOSFET constructed in accordance with the foregoing method.