摘要:
A method for fabricating a transistor on a semiconductor substrate includes varying a polysilicon doping level near a first and second edge of a diffusion region with a polysilicon doping level of a center region of a polysilicon region.
摘要:
A capacitive electrode structure for use in an integrated circuit fabricated on a substrate comprises a first electrode formed by a diffusion region in the substrate, an insulating layer formed on the diffusion region, and a second electrode formed by a conductive layer deposited on said insulating layer. To increase the capacitance per chip area of the capacitive electrode structure, a plurality of recesses are formed in the first electrode on an upper surface thereof with a lower surface of the second electrode substantially following a contour of these recesses. In one embodiment, the capacitive electrode structure is employed for a capacitor formed between a control gate and a floating gate in an EEPROM cell. Capacitors in other types of integrated circuit can be likewise formed using the electrode structure of the present invention. Preferably, the recesses in the diffusion region are formed concurrently with oxide-filled isolation trenches in the substrate used to isolate adjacent circuit elements from each other.
摘要:
A process for fabricating field effect transistors with lightly doped drain (LDD) regions having a selected width includes a method of optically detecting the width of spacers used to mask the LDD regions during the source and drain implant and a method of electrically determining (confirming) the width of the LDD regions. In the optical method, reference structures are formed concurrently with the fabrication of the gates for FETs, a spacer material is formed on the substrate, the gates and the reference structures, the spacer material is etched away and the width of the spacers is optically detected by aligning the edges of spacers extending from two reference structures separated by a known distance. In the electrical method, the width is determined by defining a test area with known dimension, forming both N.sup.+ and N.sup.- regions in the test area, measuring the resistance across the test area, calculating the resistance of the N.sup.+ and N.sup.- regions, and calculating the width of the N.sup.- region from the resistance of the N.sup.- region.
摘要:
An integrated circuit fabrication technique for a maskless method of forming contact regions in integrated circuits is disclosed. By carefully controlling implant dosages, ions of one conductivity type can be introduced into substrate regions having the same conductivity type to form enhanced characteristic contact regions without affecting the operational characteristics of substrate regions having the opposite conductivity type. The resulting cross-sectional profile of the regions of the one conductivity type allows fabrication overlap tolerances to be reduced and improves the contact regions' imperviousness to the spiking phenomenon.
摘要:
A voltage converter includes a first N-channel MOSFET transistor, an inverter, a plurality of serially-connected diodes and a second N-channel MOSFET transistor. The inverter is coupled to the gate of the first N-channel MOSFET transistor to turn on/off the voltage converter. The anode of the diodes is coupled to the source of the first N-channel MOSFET transistor and the cathode of the diodes are coupled to the drain of the second N-channel MOSFET transistor. Since the source of the second N-channel MOSFET transistor is ground, the voltage clamped at the source of the first N-channel MOSFET transistor is not higher than 3.4V when a high voltage applied to the gate of the second N-channel MOSFET transistor turns it on.
摘要:
Methods and apparatus for designing and producing programmable logic devices are provided. A logic design system may be used to analyze various implementations of a desired logic design for a programmable logic device integrated circuit. The logic design system may be used to produce configuration data for the programmable logic device in accordance with an optimized implementation. A logic circuit for a programmable logic device can be analyzed by taking into account the effects of hotspots, power supply voltage drops, and signal congestion on device performance. By modeling the performance of transistors and other components using position-dependent and signal-dependent variables such as temperature, voltage, and capacitance, the effects of congestion on device performance can be characterized and an optimum implementation of the logic design in a programmable logic device can be obtained.
摘要:
A semiconductor device and method for electrostatic discharge protection. The semiconductor device includes a first semiconductor controlled rectifier and a second semiconductor controlled rectifier. The first semiconductor controlled rectifier includes a first semiconductor region and a second semiconductor region, and the second semiconductor controlled rectifier includes the first semiconductor region and the second semiconductor region. The first semiconductor region is associated with a first doping type, and the second semiconductor region is associated with a second doping type different from the first doping type. The second semiconductor region is located directly on an insulating layer.
摘要:
Integrated circuit antifuse circuitry is provided. A metal-oxide-semiconductor (MOS) transistor serves as an electrically-programmable antifuse. The antifuse transistor has source, drain, gate, and substrate terminals. The gate has an associated gate oxide. In its unprogrammed state, the gate oxide is intact and the antifuse has a relatively high resistance. During programming, the gate oxide breaks down, so in its programmed state the antifuse transistor has a relatively low resistance. The antifuse transistor can be programmed by injecting hot carriers into the substrate of the device in the vicinity of the drain. Because there are more hot carriers at the drain than at the substrate, the gate oxide is stressed asymmetrically, which enhances programming efficiency. Feedback can be used to assist in turning the antifuse transistor on to inject the hot carriers.
摘要:
A field effect device transistor geometry and method of fabrication are described. The FET may be operated from a bias potential that forms an electrical field within the device exceeding a predetermined field strength. The device comprises a semiconductor substrate portion of a first conductivity type, said substrate portion having a major surface, and a region of a second conductivity type adjacent the major surface and adapted to receive the predetermined bias potential, the region including a subregion of like conductivity type and lesser conductivity, the subregion being positioned within the region such that the subregion receives at least that portion of the dipole electrical field including and exceeding the predetermined value.
摘要:
An integrated circuit includes a semiconductor substrate and multiple dielectric layers stacked on the substrate. Multiple interconnect metal lines and dummy metals are embedded in the dielectric layers. At least one of the dummy metals is substantially thinner than the interconnect metal lines. To form this structure, first and second pluralities of trenches are formed in the dielectric layer. At least one of the second plurality of trenches is shallower than the first plurality of trenches. The first and second pluralities of trenches are filled with a conductive layer and then planarized.