Abstract:
Metal taps for bus conductors are formed within an active layer, within one or more of the metallization levels, on the active side of a substrate in the area of a bus via. Alignment marks are formed in the same metallization level, in the same area. A slot is then blind etched from the backside of the substrate, exposing the metal taps and the alignment marks. The slot is etched, using an oxide or nitride hard mask, into the backside surface of the substrate with significantly sloped sidewalls, allowing metal to be deposited and patterned on the backside. An insulating layer and deposited metal on the backside surface of the substrate may require a blind etch to expose alignment marks, if any, but front-to-back alignment precision utilizing the exposed alignment marks may permit much smaller design rules for both the metal tabs and the backside interconnects formed from the metal layer. Backside contact pads may also be formed from the metal layer. The backside bus via slot may be etched in the body of a die, near a central region, or along the die boundary to form a shared backside bus via in which metal tabs on opposite sides of the slot connect to backside contacts on different dice after separation of the dice along the boundary. The backside bus is beneficial for sensor devices, leaving more room for sensor circuitry on the active side and simplifying packaging, for pad-limited designs, and for forming stackable integrated circuits.
Abstract:
Disclosed is a fault tolerant CMOS image sensor that includes circuitry for identifying defective pixels and masking them during image generation. Masking may involve, in one example, replacing the output of a given pixel with an average of the output of surrounding non-faulty pixels. Thus, while image sensors may be fabricated with some number of faulty pixels, the images produced by such sensors will not have undesirable bright or dark spots. The disclosed sensor includes (a) one or more pixels (active or passive) capable of providing outputs indicative of a quantity of radiation to which each of the one or more pixels has been exposed; and (b) one or more circuit elements electrically coupled to the one or more pixels and configured to identify and correct faulty pixels in the CMOS imager. The one more pixels each include a photodiode diffusion formed in a well and a tap to power or ground also formed in the well. The disclosed sensor also identifies pixels that were initially acceptable but later became defective. The newly defective pixels so identified may then be masked to thereby increase the CMOS detector lifetime.
Abstract:
An energy efficient logic gate circuit design that provides a substantially constant load to a clock source regardless of logic signal inputs to, or outputs from, the gate. The gate provides two complementary outputs and utilizes cross-coupled transistors to ensure that the outputs remain valid (complementary) after the logic inputs become invalid. Two blocks, each having a node coupling to the clock source and performing complementary logic functions, in combination with diodes for recharging the outputs of the gate, present the constant load to the clock source.
Abstract:
Metal taps for bus conductors are formed within an active layer, within one or more of the metallization levels, on the active side of a substrate in the area of a bus via. Alignment marks are formed in the same metallization level, in the same area. A slot is then blind etched from the backside of the substrate, exposing the metal taps and the alignment marks. The slot is etched, using an oxide or nitride hard mask, into the backside surface of the substrate with significantly sloped sidewalls, allowing metal to be deposited and patterned on the backside. An insulating layer and deposited metal on the backside surface of the substrate may require a blind etch to expose alignment marks, if any, but front-to-back alignment precision utilizing the exposed alignment marks may permit much smaller design rules for both the metal tabs and the backside interconnects formed from the metal layer. Backside contact pads may also be formed from the metal layer. The backside bus via slot may be etched in the body of a die, near a central region, or along the die boundary to form a shared backside bus via in which metal tabs on opposite sides of the slot connect to backside contacts on different dice after separation of the dice along the boundary. The backside bus is beneficial for sensor devices, leaving more room for sensor circuitry on the active side and simplifying packaging, for pad-limited designs, and for forming stackable integrated circuits.
Abstract:
CMOS logic circuitry powered by the clock signals wherein the addition of strategically placed diodes enables the circuits to behave in an adiabatic-like fashion.
Abstract:
Disclosed is a fault tolerant CMOS image sensor that includes circuitry for identifying defective pixels and masking them during image generation. Masking may involve, in one example, replacing the output of a given pixel with an average of the output of surrounding non-faulty pixels. Thus, while image sensors may be fabricated with some number of faulty pixels, the images produced by such sensors will not have undesirable bright or dark spots. The disclosed sensor includes (a) one or more pixels (active or passive) capable of providing outputs indicative of a quantity of radiation to which each of the one or more pixels has been exposed; and (b) one or more circuit elements electrically coupled to the one or more pixels and configured to identify and correct faulty pixels in the CMOS imager. The one more pixels each include a photodiode diffusion formed in a well and a tap to power or ground also formed in the well. The disclosed sensor also identifies pixels that were initially acceptable but later became defective. The newly defective pixels so identified may then be masked to thereby increase the CMOS detector lifetime.
Abstract:
Disclosed is a CMOS image sensor that includes circuitry for identifying defective pixels, particularly pixels having leaky access switches. The leaky access switches allow charge to escape from the pixel over a row or column line in a pixel array, thereby corrupting the outputs of an entire row or column of pixels. A disclosed test involves (a) electronically setting a defined charge in a selected pixel of the CMOS imager; (b) reading the output of the selected pixel; and (c) comparing the output of the selected pixel to an expected value based upon the defined charge set in the selected pixels. If the output significantly deviates from the expected value, then the selected pixel is identified as having a leaky access switch. Preferably, a newly fabricated sensor is first tested as described. If such leaky access switch is discovered, the imager is discarded without incurring further manufacturing cost. If, on the other hand, the imager is not found to contain a leaky access switch, it may packaged and then subjected to an optical test.
Abstract:
An apparatus and method for controlling the height of packaging above an integrated circuit package (30) comprising, a substrate (12), a silicon chip (16) and a signal wire (20), one or more height detection wires (32) extending above the top surface (26) of the silicon chip (16) and the signal wire (20) and a detector electrically connected to the height detection wire (32), wherein the height detection wire (32) and the detector form an electric circuit that is affected when a polisher of encapsulant (40) is in proximity to the height detection wire (32), is disclosed.
Abstract:
High-efficiency clock generator circuits having single or complementary outputs for driving capacitive loads. The clock generator has therein at least one pair of complementary FET switches, coupled between the output of the generator and power supply rails, and an inductor. The generator is operated at a frequency approximately equal the resonant frequency of the inductor combined with the capacitance of the load. Energy normally stored in the load and dissipated in the FETs as in conventional clock generators is instead stored in the inductor and returned to the loads for reuse.
Abstract:
A difference calculating neural network is disclosed having an array of synapse cells arranged in rows and columns along pairs of row and column lines. The cells include a pair of floating gate devices which have their control gates coupled to receive one of a pair of complementary input voltages. The floating gate devices also have complementary threshold voltages such that packets of charge are produced from the synapse cells that are proportional to the difference between the input and voltage threshold. The charge packets are accumulated by the pairs of column lines in the array.