Abstract: A low voltage transient voltage suppressing (TVS) device supported on a semiconductor substrate supporting an epitaxial layer thereon. The TVS device further includes a bottom-source metal oxide semiconductor field effect transistor (BS-MOSFET) comprises a trench gate surrounded by a drain region encompassed in a body region disposed near a top surface of the semiconductor substrate wherein the drain region interfaces with the body region constituting a junction diode and the drain region encompassed in the body region on top of the epitaxial layer constituting a bipolar transistor with a top electrode disposed on the top surface of the semiconductor functioning as a drain/collector terminal and a bottom electrode disposed on a bottom surface of the semiconductor substrate functioning as a source/emitter electrode.

Abstract: An IGBT, which is capable of reducing on resistance by reducing channel mobility, includes: an n type substrate made of SiC and having a main surface with an off angle of not less than 50° and not more than 65° relative to a plane orientation of {0001}; a p type reverse breakdown voltage holding layer made of SiC and formed on the main surface of the substrate; an n type well region formed to include a second main surface of the reverse breakdown voltage holding layer; an emitter region formed in the well region to include the second main surface and including a p type impurity at a concentration higher than that of the reverse breakdown voltage holding layer; a gate oxide film formed on the reverse breakdown voltage holding layer; and a gate electrode formed on the gate oxide film. In a region including an interface between the well region and the gate oxide film, a high-concentration nitrogen region is formed to have a nitrogen concentration higher than those of the well region and the gate oxide film.

Abstract: An electrostatic discharge (ESD) protection device including a substrate, a first doped region, a second doped region, and a third doped region, a gate and a plurality of contacts is disclosed. The substrate includes a first conductive type. The first doped region is formed in the substrate and includes a second conductive type. The second doped region is formed in the substrate and includes the second conductive type. The third doped region is formed in the substrate, includes the first conductive type and is located between the first and the second doped regions. The gate is formed on the substrate, located between the first and the second doped regions and comprises a first through hole. The contacts pass through the first through hole to contact with the third doped region.

Abstract: A MOSFET, which is capable of reducing on resistance by reducing channel mobility even when a gate voltage is high, includes: an n type substrate made of SiC and having a main surface with an off angle of 50°-65° relative to a {0001} plane; an n type reverse breakdown voltage holding layer made of SiC and formed on the main surface of the substrate; a p type well region formed in the reverse breakdown voltage holding layer distant away from a first main surface thereof; a gate oxide film formed on the well region; an n type contact region disposed between the well region and the gate oxide film; a channel region connecting the n type contact region and the reverse breakdown voltage holding layer; and a gate electrode disposed on the gate oxide film. In a region including an interface between the channel region and the gate oxide film, a high-concentration nitrogen region is formed.

Abstract: Disclosed herein is a protection element for protecting a circuit element. The protection element includes source and drain areas created in a semiconductor layer, a gate created on the semiconductor layer, sandwiching a gate insulation film between the gate and the semiconductor layer, a source electrode connected to the surface of the source area and electrically connected to the ground, a drain electrode connected to the surface of the drain area and used for receiving a surge input, and a diode connected between the source electrode and the gate.

Abstract: A bipolar semiconductor component, in particular a diode, comprising an anode structure which controls its emitter efficiency in a manner dependent on the current density in such a way that the emitter efficiency is low at small current densities and sufficiently high at large current densities, and an optional cathode structure, which can inject additional holes during commutation, and production methods therefor.

Abstract: A semiconductor device includes an SCR ESD device region disposed within a semiconductor body, and a plurality of first device regions of the first conductivity type disposed on a second device region of the second conductivity type, where the second conductivity type is opposite the first conductivity type. Also included is a plurality of third device regions having a sub-region of the first conductivity type and a sub-region of the second conductivity type disposed on the second device region. The first regions and second regions are distributed such that the third regions are not directly adjacent to each other. A fourth device region of the first conductivity type adjacent to the second device region and a fifth device region of the second conductivity type disposed within the fourth device region are also included.

Abstract: A structure includes first and second silicon controlled rectifiers (SCRs) formed in a substrate. The first and the second SCRs each include at least one component commonly shared between the first and the second SCRs.

Abstract: A semiconductor device in one embodiment has a first connection region, a second connection region and a semiconductor volume arranged between the first and second connection regions. Provision is made, within the semiconductor volume, in the vicinity of the second connection region, of a field stop zone for spatially delimiting a space charge zone that can be formed in the semiconductor volume, and of an anode region adjoining the first connection region. The dopant concentration profile within the semiconductor volume is configured such that the integral of the ionized dopant charge over the semiconductor volume, proceeding from an interface of the anode region which faces the second connection region, in the direction of the second connection region, reaches a quantity of charge corresponding to the breakdown charge of the semiconductor device only near the interface of the field stop zone which faces the second connection region.

Abstract: A high-frequency power amplifier of the type to be mounted in an RF module for mobile phones having high-frequency power field effect transistors and gate protective diodes which are coupled between the gates and the sources of the high-frequency power field effect transistors. The gate protective diodes have an n type region formed over the main surface of a p type epitaxial layer, a first p type region formed at the center of the main surface of the n type region, a second p type region formed over the main surface of the epitaxial layer around the n type region from the periphery of the main surface of the n type region, and p+ type buried layers for coupling the second p type region to a substrate body. The distance between the end portions of the p+ type buried layers and the n+ type region is 7 ?m or more.

Abstract: An electrostatic discharge (ESD) protection circuit, methods of fabricating an ESD protection circuit, methods of providing ESD protection, and design structures for an ESD protection circuit. An NFET may be formed in a p-well and a PFET may be formed in an n-well. A butted p-n junction formed between the p-well and n-well results in an NPNP structure that forms an SCR integrated with the NFET and PFET. The NFET, PFET and SCR are configured to collectively protect a pad, such as a power pad, from ESD events. During normal operation, the NFET, PFET, and SCR are biased by an RC-trigger circuit so that the ESD protection circuit is in a high impedance state. During an ESD event while the chip is unpowered, the RC-trigger circuit outputs trigger signals that cause the SCR, NFET, and PFET to enter into conductive states and cooperatively to shunt ESD currents away from the protected pad.

Abstract: An electrostatic discharge (ESD) protection circuit structure includes a dual directional silicon controlled rectifier (SCR) formed in a substrate. The SCR includes first and second P-wells laterally interposed by an N-well. A deep N-well is disposed underneath the P-wells and the N-well. First and second N-type regions are disposed in the first and second P-wells, respectively, and are coupled to a pair of pads. First and second P-type regions are disposed in the first and second P-wells, respectively, are coupled to the pads, and are disposed closer to the N-well than the first and second N-type regions, respectively.

Abstract: A semiconductor device includes an SCR ESD device region disposed within a semiconductor body, and a plurality of first device regions of the first conductivity type disposed on a second device region of the second conductivity type, where the second conductivity type is opposite the first conductivity type. Also included is a plurality of third device regions having a sub-region of the first conductivity type and a sub-region of the second conductivity type disposed on the second device region. The first regions and second regions are distributed such that the third regions are not directly adjacent to each other. A fourth device region of the first conductivity type adjacent to the second device region and a fifth device region of the second conductivity type disposed within the fourth device region are also included.

Abstract: Disclosed herein are non-volatile memory devices with asymmetric source/drain junctions and a method for fabricating the same. According to the method, a gate stack is formed on a semiconductor substrate, and impurity ions are implanted at a predetermined angle to form a source/drain junction in the semiconductor substrate. Thermal treatment of the semiconductor substrate forms an asymmetrically disposed source/drain junction between adjacent gate stacks.

Abstract: The invention is directed to a protection circuit for protecting IC chips against ESD. An ESD protection circuit for an integrated circuit chip may comprise an isolated NMOS transistor, which may comprise an isolation region isolating a backgate from a substrate, and a first and second doped regions and a gate formed on the backgate. The ESD protection circuit may further comprise a first terminal to connect the isolation region to a first electrical node, and a second terminal to connect the second doped region to a second electrical node. The first electrical node may have a higher voltage level than the second electrical node, and the gate and backgate may be coupled to the second terminal.

Abstract: A semiconductor device of the present invention comprises: a P type semiconductor substrate, an N-well, a first P+ diffusion region, a second P+ diffusion region, a Schottky diode, a first N+ diffusion region, a second N+ diffusion region, a third P+ diffusion region, a fourth P+ diffusion region, a first insulation layer, a second insulation layer, a first parasitic bipolar junction transistor (BJT), and a second parasitic BJT. The Schottky diode is coupled to an input signal. The first N+ diffusion region and the second N+ diffusion region are coupled to a voltage source, respectively. When a voltage level of the input signal is higher than a voltage level of the voltage source, the Schottky diode conducts charges to make the first parasitic BJT and the second parasitic BJT not conducted.

Abstract: An ESD device includes a low doped well connected to a first contact and a diffusion area connected to a second contact. A substrate between the low doped well and the diffusion area has a dopant polarity that is opposite a dopant polarity of the low doped well and the diffusion area. A distance between the low doped well and the diffusion area determines a triggering voltage of the ESD device. A depletion region is formed between the low doped well and the substrate when a reverse bias voltage is applied to the ESD device. A current discharging path is formed between the first contact and the second contact when the depletion region comes in to contact with the diffusion area. The substrate is biased by a connection to the second contact. Alternatively, an additional diffusion area with the same dopant polarity, connected to a third contact, biases the substrate.

Abstract: A design structure is embodied in a machine readable medium for designing, manufacturing, or testing a design. The design structure includes first and second silicon controlled rectifiers (SCRs) formed in a substrate. Further, the first and the second SCRs each include at least one component commonly shared between the first and the second SCRs.

Abstract: A design structure for electrostatic discharge protection comprises a first data representing a first electrostatic discharge (ESD) protection circuit and a second data representing a second ESD protection circuit. A parallel connection of two ESD protection units, each providing a discharge path for electrical charges of opposite types, provides ESD protection circuit for positive and negative voltage swings in the circuit. Each of the multiple emitter-base regions are cascaded such that the base of one emitter-base region is directly wired to the emitter of an adjacent emitter-base region. The first data represents a first ESD protection unit providing protection on one type of voltage swing, and the second data represents a second ESD protection unit providing protection on the other type of voltage swing.

Abstract: Embodiments discussed herein relate to processes of producing a field stop zone within a semiconductor substrate by implanting dopant atoms into the substrate to form a field stop zone between a channel region and a surface of the substrate, at least some of the dopant atoms having energy levels of at least 0.15 eV below the energy level of the conduction band edge of semiconductor substrate; and laser annealing the field stop zone.

Abstract: The invention provides an electrostatic discharge (ESD) protection device with an increased capability to discharge ESD generated current with a reduced device area. The ESD protection device comprises a grounded gate MOS transistor (1) with a source region (3) and a drain region (4) of a first semiconductor type interposed by a first well region (7) of a second semiconductor type. Second well regions (6) of the first semiconductor type, interposed by the first well region (7), are provided beneath the source region (3) and the drain region (4). Heavily doped buried regions (8,9) of the same semiconductor types, respectively, as the adjoining well regions (6,7) are provided beneath the well regions (6,7).

Abstract: A high-frequency power amplifier of the type to be mounted in an RF module for mobile phones having high-frequency power field effect transistors and gate protective diodes which are coupled between the gates and the sources of the high-frequency power field effect transistors. The gate protective diodes have an n type region formed over the main surface of a p type epitaxial layer, a first p type region formed at the center of the main surface of the n type region, a second p type region formed over the main surface of the epitaxial layer around the n type region from the periphery of the main surface of the n type region, and p+ type buried layers for coupling the second p type region to a substrate body. The distance between the end portions of the p+ type buried layers and the n+ type region is 7 ?m or more.

Abstract: Generally, a power MOSFET mainly includes an active region occupying most of an internal region (a region where a gate electrode made of polysilicon or the like is integrated), and a surrounding gate contact region (where the gate electrode made of polysilicon or the like is derived outside a source metal covered region to make contact with a gate metal) (see FIG. 65 in a comparative example). Since the gate electrode made of polysilicon or the like has a stepped portion existing between both regions, a focus margin may be reduced in a lithography step, including exposure or the like, for formation of a contact hole for a source or for a gate. The invention of the present application provides a semiconductor device having a trench gate type power MISFET with a gate electrode protruding from an upper surface of a semiconductor substrate, in which respective main upper surfaces of the gate electrode in an active region and a gate contact region are substantially at the same height.

Abstract: The invention relates to a high-frequency integrated circuit requiring ESD protection for a circuit node. One or more metallic layer is deposited within the integrated circuit and patterned to form a transmission line. The metallic layers are generally already present in the integrated circuit for signal routing. The transmission line is coupled between the circuit node and a terminal of an ESD protection device, with a transmission line return conductor coupled to a high-frequency ground. The transmission line is formed with an electrical length that transforms the impedance of the ESD protection device substantially into an open circuit at the circuit node at an operational frequency of the integrated circuit. The other terminal of the ESD protection device is coupled to the high-frequency ground.

Abstract: An asymmetric insulated-gate field-effect transistor (100) has a source (240) and a drain (242) laterally separated by a channel zone (244) of body material (180) of a semiconductor body. A gate electrode (262) overlies a gate dielectric layer (260) above the channel zone. A more heavily doped pocket portion (250) of the body material extends largely along only the source. Each of the source and drain has a main portion (240M or 242M) and a more lightly doped lateral extension (240E or 242E). The drain extension is more lightly doped than the source extension. The maximum concentration of the semiconductor dopant defining the two extensions occurs deeper in the drain extension than in the source extension. Additionally or alternatively, the drain extension extends further laterally below the gate electrode than the source extension. These features enable the threshold voltage to be highly stable with operational time.

Abstract: A very low VCEON non punch through trench IGBT built-in non-epitaxial float zone silicon has a depletion stop layer structure added to its bottom surface.

Abstract: A high-frequency power amplifier of the type to be mounted in an RF module for mobile phones having high-frequency power field effect transistors and gate protective diodes which are coupled between the gates and the sources of the high-frequency power field effect transistors. The gate protective diodes have an n type region formed over the main surface of a p type epitaxial layer, a first p type region formed at the center of the main surface of the n type region, a second p type region formed over the main surface of the epitaxial layer around the n type region from the periphery of the main surface of the n type region, and p+ type buried layers for coupling the second p type region to a substrate body. The distance between the end portions of the p+ type buried layers and the n+ type region is 7 ?m or more.

Abstract: A semiconductor device (1) includes a plurality of photodiodes (20) on a semiconductor substrate (11). Cathodes (22) and a common anode (21) of the plurality of photodiodes (20 (20a, 20b)) are formed so as to be electrically independent from the semiconductor substrate (11), the plurality of photodiodes (20) have the common anode (21) and the plurality of separate cathodes (22), and an output of the common anode (21) is considered to be equivalent to a sum of outputs of the plurality of separate photodiodes (20). Alternatively, the plurality of photodiodes have a common cathode and a plurality of separate anodes, and an output of the common cathode is considered to be equivalent to a sum of outputs of a plurality of separate photodiodes. By completely electrically isolating the anode and the cathode of the photodiodes from the substrate, the noise characteristic can be reduced, and crosstalk can be reduced.

Abstract: A semiconductor device comprises at least one switching element. The at least one switching element comprises a first channel terminal, a second channel terminal and a switching terminal, the switching element being arranged such that an impedance of the switching element between the first and second channel terminals is dependant upon a voltage across the switching terminal and the first channel terminal. The semiconductor device further comprises a resistance element operably coupled between the first channel terminal of the at least one switching element and a reference node, and a clamping structure operably coupled between the switching terminal of the switching element and the reference node.

Abstract: An ESD protection device for a pad includes an adjusting circuit, a snapback element and a control circuit. The adjusting circuit includes a silicon controlled rectifier (SCR) coupled to the pad. The SCR includes a first diode. The snapback element is coupled to a first N pole of the first diode when a second diode is not used, and is coupled to a second N pole of the second diode when the second diode is used. The control circuit is coupled to the first N pole. In a normal operation mode, the control circuit provides a first voltage to the first N pole so that the first N pole collects a plurality of charges and the SCR is turned off. In an ESD mode, the control circuit does not provide the first voltage to the first N pole so that the first N pole does not collect the charges.

Abstract: A semiconductor device 10 comprises a P type base region 13 formed in an N? type base region 11, and N+ type emitter regions 14 formed plurally in the P type base region 13 so as to be spaced form each other. The N+ type emitter regions 14 are formed such that the rate of the area occupied by the N+ type emitter region 14 in the P type base region 13 at the center part of the semiconductor device 10 is smaller than the rate of the area occupied by the N+ type emitter region 14 in the P type base region 13 at the peripheral part of the semiconductor device 10.

Abstract: An electrostatic discharge circuit between a first pad and a second pad including an electrostatic discharge circuit element, including a bipolar transistor path and a resistor path, the electrostatic discharge circuit element alternately discharging an electrostatic current through the bipolar transistor path and the resistor path.

Abstract: A high-voltage, low-leakage, bidirectional electrostatic discharge (ESD, or other electrical overstress) protection device includes a doped well disposed between the terminal regions and the substrate. The device includes an embedded diode for conducting current in one direction, and a transistor feedback circuit for conducting current in the other direction. Variations in the dimensions and doping of the doped well, as well as external passive reference via resistor connections, allow the circuit designer to flexibly adjust the operating characteristics of the device, such as trigger voltage and turn-on speed, to suit the required mixed-signal operating conditions.

Abstract: An improved layout pattern for electrostatic discharge protection is disclosed. A first heavily doped region of a first type is formed in a well of said first type. A second heavily doped region of a second type is formed in a well of said second type. A battlement layout pattern of said first heavily doped region is formed along the boundary of said first heavily doped region and said second heavily doped region. A battlement layout pattern of said second heavily doped region is formed along the boundary of said first heavily doped region and said second heavily doped region. By adjusting a distance between the battlement layout pattern of a heavily doped region and a edge of well of said second type, i.e. n-well, a first distance will be shorter than what is typically required by the layout rules of internal circuit; and a second distance will be longer than the first distance to ensure that the I/O device have a better ESD protection capability.

Abstract: An electrostatic discharge (ESD) transistor structure includes a self-aligned outrigger less than 0.4 microns from a gate electrode that is 50 microns wide. The outrigger is fabricated on ordinary logic transistors of an integrated circuit without severely affecting the performance of the transistors. The outrigger is used as an implant blocking structure to form first and second drain regions on either side of a lightly doped region that underlies the outrigger. The self-aligned outrigger and the lightly doped region beneath it are used to move the location of avalanche breakdown upon an ESD event away from the channel region. Durability is extended when fewer “hot carrier” electrons accumulate in the gate oxide. A current of at least 100 milliamperes can flow into the drain and then through the ESD transistor structure for a period of more than 30 seconds without causing a catastrophic failure of the ESD transistor structure.

Abstract: A semiconductor device includes an SCR ESD device region disposed within a semiconductor body, and a plurality of first device regions of the first conductivity type disposed on a second device region of the second conductivity type, where the second conductivity type is opposite the first conductivity type. Also included is a plurality of third device regions having a sub-region of the first conductivity type and a sub-region of the second conductivity type disposed on the second device region. The first regions and second regions are distributed such that the third regions are not directly adjacent to each other. A fourth device region of the first conductivity type adjacent to the second device region and a fifth device region of the second conductivity type disposed within the fourth device region are also included.

Abstract: A semiconductor device includes a transistor region, a first guard ring, a second guard ring, and a silicide region. A first-conductive-type transistor is formed in the transistor region. The first guard ring is a second-conductive-type first impurity diffusion layer surrounding the transistor region with a first width, and is coupled to a first reference potential. The second guard ring is a first-conductive-type transistor second impurity diffusion layer surrounding the first guard ring with a second width. The silicide region is formed on the surface of the second guard ring such that substantially no silicide is formed on a portion of the surface of the second guard ring on the side facing a drain region of the first-conductive-type transistor, and is connected to a second reference potential line whose potential is higher than that of the first reference potential line.

Abstract: A semiconductor device includes: an n-channel MIS transistor and a p-channel MIS transistor. An n-channel MIS transistor includes: a first gate insulating film having an amorphous layer or an epitaxial layer formed on a p-type semiconductor region between a first source/drain regions; and a first gate electrode having a stack structure formed with a first metal layer and a first compound layer. The first metal layer is formed on the first gate insulating film and made of a first metal having a work function of 4.3 eV or smaller, and the first compound layer is formed on the first metal layer and contains a compound of a second metal and a IV-group semiconductor. The second metal is different from the first metal. A p-channel MIS transistor includes a second gate electrode having a second compound layer containing a compound of the same composition as the first compound layer.

Abstract: A semiconductor device includes a transistor, a first diode, and a second diode. A collector of the transistor and a cathode of the first diode are electrically connected. The collector of the transistor and a cathode of the second diode are electrically connected, and an emitter of the transistor and an anode of the second diode are electrically connected. The first diode and the second diode are formed in an identical substrate. Thereby, the semiconductor device can be produced in a smaller size and in less steps.

Abstract: A semiconductor device includes a substrate and a memory cell formed on the substrate. The memory cell includes a word line. The semiconductor device also includes a protection area formed in the substrate, a conductive structure configured to extend the word line to the protection area, and a contact configured to short the word line and the protection area.

Abstract: An improved lateral bipolar electrostatic discharge (ESD) protection device (40) comprises a semiconductor (SC) substrate (42), an overlying epitaxial SC layer (44), emitter-collector regions (48, 50) laterally spaced apart by a first distance (52) in the SC layer, a base region (54) adjacent the emitter region (48) extending laterally toward and separated from the collector region (50) by a base-collector spacing (56) that is selected to set the desired trigger voltage Vt1. By providing a buried layer region (49) under the emitter region (48) Ohmically coupled thereto, but not providing a comparable buried layer region (51) under the collector region (50), an asymmetrical structure is obtained in which the DC trigger voltage (Vt1DC) and transient trigger voltage (Vt1TR) are closely matched so that |Vt1TR?Vt1DC|˜0.

Abstract: A design structure for a circuit providing the same trigger voltage across the multiple fingers is provided, which comprises a data representing an external current injection source connected to individual fingers of a multi-finger semiconductor device. For example, the external injection current is supplied to the body of a MOSFET or the gate of a thyristor. The magnitude of the supplied current from each external current injection source is adjusted so that each finger has the same trigger voltage. The external current supply circuit may comprise diodes or an RC triggered MOSFET. The components of the external current supply circuit may be tuned to achieve a desired predetermined trigger voltage across all fingers of the multi-finger semiconductor device.

Abstract: An ESD protection device includes a source region, a channel region adjacent the source region, and an elongated drain region spaced from the source region by the channel region. The elongated drain region includes an unsilicided portion adjacent the channel and a silicided portion spaced from channel region by the unsilicided portion. A first ESD region is located beneath the silicided portion of the elongated drain region and a second ESD region is located beneath the unsilicided portion of the elongated drain region, the second ESD region being spaced from the first ESD region.

Abstract: An electrostatic discharge (ESD) protection clamp (61) for I/O terminals (22, 23) of integrated circuits (ICs) (24) comprises an NPN bipolar transistor (25) coupled to an integrated Zener diode (30). Variations in the break-down current-voltage characteristics (311, 312, 313, 314) of multiple prior art ESD clamps (31) in different parts of the same IC chip is avoided by forming the anode (301) of the Zener (30) in the shape of a base-coupled P+ annular ring (75) surrounded by a spaced-apart N+ annular collector ring (70) for the cathode (302) of the Zener (30).

Abstract: A semiconductor device is provided which includes a semiconductor substrate, a gate structure formed on the substrate, sidewall spacers formed on each side of the gate structure, a source and a drain formed in the substrate on either side of the gate structure, the source and drain having a first type of conductivity, a lightly doped region formed in the substrate and aligned with a side of the gate structure, the lightly doped region having the first type of conductivity, and a barrier region formed in the substrate and adjacent the drain. The barrier region is formed by doping a dopant of a second type of conductivity different from the first type of conductivity.

Abstract: An electric discharge device includes a bipolar transistor configuration comprising a base, an emitter, and a collector. At least one pinched resistor is formed in a region comprising both the base and emitter so as to produce a pinched resistive area that develops a voltage once the bipolar transistor experiences junction breakdown.

Abstract: An integrated circuit system includes a first device in a first power domain, and a second device coupled to the first device in a second power domain. A circuit module is coupled between the first device and a power supply voltage or between the first device and a complementary power supply voltage in the first power domain for increasing an impedance against an ESD current flowing from the first device to the second device during an ESD event.

Abstract: An input/output (I/O) mixed-voltage drive circuit and electrostatic discharge protection device for coupling to an I/O pad. The device includes an NFET device having a gate, a drain, a source and body, the gate adapted for coupling to a pre-drive circuit, the source and the body being coupled to one another and to ground. The device also includes a bipolar junction transistor having a collector, an emitter and a base, the emitter being coupled to the drain of the NFET and the collector being coupled to the I/O pad.

Abstract: An ESD protection structure includes, in part, a NMOS transistor having a source and drain in a well in a substrate and a gate on the substrate with the source and drain being connected between ground and a series diode, and the gate being connected to ground. The structure further includes a diode having a cathode connected to the input pad and an anode connected to the well so that the diode is reverse-biased in the event of a positive voltage ESD event on the input pad. As a result, in a positive voltage ESD event, the avalanche effect rapidly injects current into the substrate and therefore into the base of the parasitic bipolar transistor so as to trigger the transistor into conduction and discharge the ESD pulse. Alternatively, the diode is a Zener diode and the current is generated by the Zener effect. A complementary structure provides protection against a negative ESD pulse.

Abstract: The present invention is directed to an electrostatic discharge (ESD) device with an improved ESD robustness for protecting output buffers in I/O cell libraries. The ESD device according to the present invention uses a novel I/O cell layout structure for implementing a turn-on restrained method that reduces the turn-on speed of an ESD guarded MOS transistor by adding a pick-up diffusion region and/or varying channel lengths in the layout structure.