Abstract: The present invention relates to an electrostatic discharge (ESD) protection scheme and particularly to a string contact structure for an improved ESD performance. In an embodiment, the invention provides a method for forming an ESD protection circuit for protecting an internal circuit from damage due to an ESD voltage appearing on a pad coupled to a clamp device including a first terminal and a second terminal. The method includes forming a string contact along the first terminal and the second terminal of the clamp device. The method further includes forming one or more conductive layers on the string contact to couple the first terminal and the second terminal of the clamp device to the pad and a ground pad.

Abstract: A semiconductor device is provided. In an embodiment, the semiconductor device includes an inverter. The inverter is coupled to an NMOS device. The NMOS device may be protection device which protects the inverter from charging effects and/or plasma induced damage. The NMOS device may be coupled to a power source (e.g., Vss). The NMOS device may be further coupled to a capacitor. The charge of the capacitor may discharge a current through the NMOS device to the power source.

Abstract: A semiconductor device includes a gate electrode over a semiconductor substrate, wherein the gate electrode has a gate width direction; a source/drain region in the semiconductor substrate and adjacent the gate electrode, wherein the source/drain region has a first width in a direction parallel to the gate width direction; and a bulk pick-up region in the semiconductor substrate and abutting the source/drain region. The bulk pick-up region and the source/drain region have opposite conductivity types. The bulk pick-up region has a second width in the width direction, and wherein the second width is substantially less than the first width.

Abstract: Embodiments of the invention relate to an electrostatic discharge (ESD) device and method for forming an ESD device. An embodiment is an ESD protection device comprising a p well disposed in a substrate, an n well disposed in the substrate, a high voltage n well (HVNW) disposed between the p well and the n well in the substrate, a source n+ region disposed in the p well, and a plurality of drain n+ regions disposed in the n well.

Abstract: The present invention discloses a tie-off circuit coupled between a first potential and a gate of a MOS device whose source is connected to a second potential. The tie-off circuit includes at least one resistor and at least on diode. The resistor is coupled between the gate of the MOS device and the first potential for preventing the gate of the MOS device from floating during a normal circuit operation. The diode is coupled between the gate of the MOS device and the first potential, in parallel with the resistor, for reducing a voltage difference across a gate oxide layer of the MOS device during an electrostatic discharge (ESD) event, thereby protecting the same from ESD damage.

Abstract: An electrostatic discharge (ESD) protection circuit includes a buried oxide layer; a semiconductor layer on the buried oxide layer; and a first and a second MOS device. The first MOS device includes a first gate over the semiconductor layer; a first well region having a portion underlying the first gate; and a first source region and a first drain region in the semiconductor layer. The second MOS device includes a second gate over the semiconductor layer; and a second well region having a portion underlying the first gate. The second well region is connected to a discharging node. The first well region is connected to the discharging node through the second well region, and is not directly connected to the discharging node. The second MOS device further includes a second source region and a second drain region in the semiconductor layer and adjoining the second well region.

Abstract: A sensor for electrostatic discharge (ESD) protection includes a voltage divider and a device coupled thereto. The sensor is coupled to an input terminal of the sensor, wherein a voltage drop occurs across the voltage divider and a high state voltage is generated at an output terminal of the sensor when an ESD voltage pulse is applied to the input terminal of the sensor. The device maintains the high state voltage at the output terminal of the sensor, while the ESD voltage pulse is applied to the input terminal of the sensor. A method for ESD protection includes the step of pulling down a gate terminal of a MOS transistor of an ESD circuit to a low state voltage when an ESD pulse is sensed.

Abstract: An electrostatic discharge (ESD) structure connected to a bonding pad in an integrated circuit comprising: a P-type substrate with one or more first P+ regions connected to a low voltage supply (GND), a first Nwell formed in the P-type substrate, one or more second P+ regions disposed inside the first Nwell and connected to the bonding pad, at least one first N+ region disposed outside the first Nwell but in the P-type substrate and connected to the GND, at least one second N+ region disposed outside the first Nwell but in the P-type substrate and connected to the bonding pad, wherein the second N+ region is farther away from the first Nwell than the first N+ region, and at least one conductive material disposed above the P-type substrate between the first and second N+ regions and coupled to the GND, wherein the first N+ region, the second N+ region and the conductive material form the source, drain and gate of an NMOS transistor, respectively, and the first P+ region is farther away from the first Nwell tha

Abstract: An electrostatic discharge (ESD) protection device includes a diode located in a substrate and an N-type metal oxide semiconductor (NMOS) device located in the substrate adjacent the diode, wherein both the diode and the NMOS are coupled to an input device, and at least a portion of the diode and at least a portion of the NMOS device collectively form an ESD protection device.

Abstract: Electrostatic discharge (ESD) protection in high voltage semiconductor devices is disclosed that provides enhanced current isolation between transistor drains or sources by creating an isolation island surrounding the drains or sources. This isolation island can be a higher-doped region within which the drain/source lies. The junction between the higher doping of this island region and the surrounding substrates operates to limit the amount of current that passes through the drain/source. Additionally, oxide features may be used to create an island surrounding the drain/source contact. Again, this isolating effect makes the amount of current passing through the device more uniform, which protects the device from damage due to an ESD event.

Abstract: The invention describes a structure and a process for providing ESD semiconductor protection with reduced input capacitance. The structure consists of heavily doped P+ guard rings surrounding the I/O ESD protection device and the Vcc to Bss protection device. In addition, there is a heavily doped N+ guard ring surrounding the I/O protection device its P+ guard ring. The guard rings enhance structure diode elements providing enhanced ESD energy discharge path capability enabling the elimination of a specific conventional Vss to I/O pad ESD protection device. This reduces the capacitance seen by the I/O circuit while still providing adequate ESD protection for the active circuit devices.

Abstract: A semiconductor structure for electrostatic discharge protection is presented. The semiconductor structure comprises a grounded gate nMOS (GGNMOS) having a substrate, a gate electrode, a source region and a drain region. A plurality of contact plugs is formed on the source and drain side. A plurality of first level vias is electrically coupled to the GGNMOS and has a substantially asymmetrical layout in the source and drain regions. A second level via(s) re-routes the ESD current to the desired first level vias. The uniformity of the current flow in the GGNMOS is improved.

Abstract: An ESD protection circuit includes a silicon controlled rectifier coupled between a circuit pad and ground for bypassing an ESD current from the circuit pad during an ESD event. An MOS transistor, having a source shared with the silicon controlled rectifier, is coupled between the pad and ground for reducing a trigger voltage of the silicon controlled rectifier during the ESD event. The silicon controlled rectifier has a first diode serially connected to a second diode in an opposite direction, between the pad and the shared source of the MOS transistor, for functioning as a bipolar transistor. In a layout view, a first area for placement of the first and second diodes is interposed between at least two separate sets of second areas for placement of the MOS transistor.

Abstract: Input/output devices with robustness of ESD protection are provided. An input/output device comprises an input/output pad, a first NMOS transistor, a second NMOS transistor and an ESD detector. The first NMOS transistor comprises a first drain, a first source and a first gate, wherein the first source and the first gate are coupled to a first ground power rail, and the first drain to the input/output pad. The second NMOS transistor comprises a second drain, a second source and a second gate, wherein the second source is coupled to the first ground power rail, the second drain to the input/output pad, and the second gate to a first pre-driver. When an ESD event is detected, the ESD detector makes the first pre-driver couple the second gate to the first ground power rail, thereby the first and second transistors evenly discharge ESD current.

Abstract: An electrostatic discharge protection device comprising a multi-finger gate, a first lightly doped region of a second conductivity, a first heavily doped region of the second conductivity, and a second lightly doped region of the second conductivity. The multi-finger gate comprises a plurality of fingers mutually connected in parallel over an active region of a first conductivity. The first lightly doped region of a second conductivity is disposed in the semiconductor substrate and between two of the fingers. The first heavily doped region of the second conductivity is disposed in the first lightly doped region of the second conductivity. The second lightly doped region of the second conductivity is beneath and adjoins the first lightly doped region of the second conductivity.

Abstract: The invention describes a structure and a process for providing ESD semiconductor protection with reduced input capacitance. The structure consists of heavily doped P+ guard rings surrounding the I/O ESD protection device and the Vcc to Bss protection device. In addition, there is a heavily doped N+ guard ring surrounding the I/O protection device its P+ guard ring. The guard rings enhance structure diode elements providing enhanced ESD energy discharge path capability enabling the elimination of a specific conventional Vss to I/O pad ESD protection device. This reduces the capacitance seen by the I/O circuit while still providing adequate ESD protection for the active circuit devices.

Abstract: A semiconductor device includes a gate electrode over a semiconductor substrate, wherein the gate electrode has a gate width direction; a source/drain region in the semiconductor substrate and adjacent the gate electrode, wherein the source/drain region has a first width in a direction parallel to the gate width direction; and a bulk pick-up region in the semiconductor substrate and abutting the source/drain region. The bulk pick-up region and the source/drain region have opposite conductivity types. The bulk pick-up region has a second width in the width direction, and wherein the second width is substantially less than the first width.

Abstract: A layout structure for an ESD protection circuit includes a first MOS device area having a first and second doped regions of the same polarity disposed at two sides of a first conductive gate layer, and a third doped region disposed along the first doped region at one side of the first conductive gate layer. The third doped region has a polarity different from that of the first and second doped regions, such that the third doped region and the second doped region form a diode for enhancing dissipation of ESD current during a negative ESD event.

Abstract: An electrostatic discharge-protected MOS structure is disclosed. An electrostatic discharge-protected MOS structure includes a semiconductor substrate of a first type, a first well of the first type formed in the semiconductor substrate, and a second well of a second type disposed adjacent to the first well. The MOS structure further includes a source region, a drain region, and an oxide layer and a polysilicon layer for forming a gate electrode of the MOS structure. In addition, the MOS structure includes a parasitic SCR comprising at least a parasitic NPN bipolar transistor and a buried layer of the second type interposed between the second well and the semiconductor substrate. The buried layer functions to lower a resistance of the semiconductor substrate during an ESD event so that ESD currents generated by the parasitic SCR are dissipated through the buried layer and the semiconductor substrate, thereby protecting the MOS structure.

Abstract: An electrostatic discharge (ESD) protection device includes a diode located in a substrate and an N-type metal oxide semiconductor (NMOS) device located in the substrate adjacent the diode, wherein both the diode and the NMOS are coupled to an input device, and at least a portion of the diode and at least a portion of the NMOS device collectively form an ESD protection device.