Abstract:
A bit-line pull-up circuit for an SRAM device which utilizes an improved diffusion structure for enhanced immunity of the SRAM device against electrostatic discharge. The improved diffusion structure includes an undivided diffusion region that serves as a common drain for a plurality of MOS transistors. The undivided diffusion region has at least a pair of recessed diffusion edges formed on opposite sides thereof. The forming of the recessed diffusion edges prevents the so-called electrical field crowding effect and also enhances ESD immunity for the MOS transistor. Further, since the drain diffusion region is an undivided area, an increased number of metal contact windows are provided therein, and at least one of the metal contact windows is arranged substantially between the two recessed diffusion edges. In the event of an electrostatic discharge, this allows the discharge current flowing into the drain to be divided into a greater number of small-magnitude currents flowing to the source.
Abstract:
An electrostatic discharge protection device formed on a substrate. The electrostatic discharge protection device includes a first isolation region formed over the substrate, an active region formed over the substrate and enclosed by the first isolation region, a second isolation region formed on the substrate and substantially surrounded by the active region, a first gate element formed in the active region, the first gate element having a first end extending over the first isolation region and a second end extending over the second isolation region, a drain region formed in the active region at a first side of the first gate element, a source region formed in the active region at a second side of the first gate element, a drain contact for electrically coupling the drain region to a first node, and a source contact for electrically coupling the source region to a second node.
Abstract:
A pin-assignment method is provided for use on an IC package to arrange pin connections. The pin-assignment method can allow an improvement in the electro-static discharge (ESD) protection capability for the IC chip packed in the IC package. Specifically, the pin-assignment method organizes the no-connect pins of the IC package into groups and then assigns each of the two pins that bound each no-connect pin group to be connected to a power bus of the IC chip. This allows for an increased ESD protective capability for the no-connect pins. Moreover, the pin-assignment method can simplify the wiring complexity of the IC package.
Abstract:
An ESD protection circuit has a VDD bus, a VSS bus, an IC pad, a PMOS transistor coupled to the IC pad and the VDD bus, and an NMOS transistor coupled to the IC pad and the VSS bus. The pitch of the PMOS can smaller than the pitch of the NMOS, and the drain-contact-to-gate-spacing (DCGS) for the PMOS can be smaller than the DCGS for the NMOS.
Abstract:
A number of different arrangements of island structures are utilized for improved ESD protection. The MOSFET structure provides islands that are selectively positioned among a group of ESD protection devices for protecting the power-bus, input pins, output pins and I/O pins to achieve ESD improvement in a manner which improves overall ESD protection strength while reducing the complexity of IC simulation and modeling.
Abstract:
A bond pad structure for use in wire bonding application during the packaging operation of semiconductor devices which contains a bond frame structure for holding the bond pad in place to prevent bond pad peel-off problem. The bond pad structure is a laminated structure containing a metal bond pad layer, a middle dielectric layer, and an underlying layer formed above a wafer surface. A guard band structure is formed in a spaced apart relationship from the metal bond pad layer which is connected to the underlying layer by a hole-fill. The underlying layer can be a metal layer, a semiconductor layer such as a polysilicon layer, or any material layer which has good adhesion with the hole fill material. The guard band structure exerts a downward force against the middle dielectric layer to help keeping the middle dielectric layer in place. The guard band structure also creates a localized discontinuity in the middle dielectric layer to intercept cracks that may be formed in the middle layer around the edge of the metal bond pad which is believed a main cause of bond pad peel-off problem.
Abstract:
A MOSFET structure uses angled poly-gate segments positioned between drain and source diffusion regions such that the entire continuous gate element structure is within the active region in a substrate. The gate-to-source diffusion edges are continuous along the gate body, so as to cascade the snap-back action to enhance uniform turn on of the entire gate element during an ESD event. The angled gate segments provide a total gate-to-area ratio greater than that of a multi-finger-gate configuration within an equal size active region. In addition, the gate signal RC delay is sufficient to provide noise suppression of the output voltage when the MOSFET is used as a high current-drive CMOS output buffer.
Abstract:
A driving circuit such as for driving pixels of an LCD includes first and second digital-to-analog converters respectively coupled to receive first and second digital input values. The outputs of the first and second digital-to-analog converters are connected to first and second output transistors, the outputs of which are connected together to a driving voltage output terminal. A predetermined voltage is applied to the gate of each output transistor. The first and second digital-to-analog converters and their associated output transistors correspond to upper and lower ranges of output voltage. During a display cycle, one digital-to-analog converter receives a digital value to be output as a driving voltage, while the other digital-to-analog converter receives a digital value to be output as a voltage that renders its associated output transistor nonconductive. Voltage values are selected so that the output transistors can be designed to withstand voltage values that are less than the maximum value of the full voltage range that the driving circuit can output.
Abstract:
A driving circuit suitable for driving pixels in an LCD array includes dual channel digital-to-analog converters (DACs). Each dual channel DAC outputs on channel A and channel B outputs the analog version of an applied digital signal and a non-passing voltage, respectively, and switches these outputs in response to a toggle signal. The DAC outputs are applied to paired output transistors such that one transistor of each transistor pair is rendered conductive and the other transistor is rendered non-conductive during each display cycle. By designating alternate DACs to receive upper and lower voltage range driving voltages, respectively, each pixel is alternately driven by voltages in the upper and lower voltage range and the driving voltage range applied to each pixel in one display cycle is opposite to the voltage range applied to the immediately adjacent pixels in the same display cycle.
Abstract:
An integrated semiconductor device includes a substrate having a buried shallow trench isolation structure and an epitaxial layer disposed over the substrate and the buried shallow trench isolation structure. The epitaxial layer includes a shallow trench isolation structure that extends over the buried shallow trench isolation structure in the substrate to substantially reduce leakage current in the substrate to prevent device latch-up.