Abstract: An area-efficient, high voltage, dual polarity ESD protection device (200) is provided for protecting multiple pins (30, 40) against ESD events by using a plurality of stacked NPN devices (38, 48, 39) which have separately controllable breakdown voltages and which share one or common NPN devices (39), thereby reducing the footprint of the high voltage ESD protection circuits without reducing robustness and functionality.

Abstract: An electrostatic discharge (ESD) protection clamp (21, 21?, 70, 700) for protecting associated devices or circuits (24), comprises a bipolar transistors (21, 21?, 70, 700) in which doping of facing base (75) and collector (86) regions is arranged so that avalanche breakdown occurs preferentially within a portion (84, 85) of the base region (74, 75) of the device (70, 700) away from the overlying dielectric-semiconductor interface (791). Maximum variations (?Vt1)MAX of ESD triggering voltage Vt1 as a function of base-collector spacing dimensions D due, for example, to different azimuthal orientations of transistors (21, 21?, 70, 700) on a semiconductor die or wafer is much reduced. Triggering voltage consistency and manufacturing yield are improved.

Abstract: Protection device structures and related fabrication methods are provided. An exemplary protection device includes a first bipolar junction transistor, a second bipolar junction transistor, a first zener diode, and a second zener diode. The collectors of the first bipolar junction transistors are electrically coupled. A cathode of the first zener diode is coupled to the collector of the first bipolar transistor and an anode of the first zener diode is coupled to the base of the first bipolar transistor. A cathode of the second zener diode is coupled to the collector of the second bipolar transistor and an anode of the second zener diode is coupled to the base of the second bipolar transistor. In exemplary embodiments, the base and emitter of the first bipolar transistor are coupled at a first interface and the base and emitter of the second bipolar transistor are coupled at a second interface.

Abstract: An electrostatic discharge (ESD) protection clamp (21, 21?, 70, 700) for protecting associated devices or circuits (24), comprises a bipolar transistors (21, 21?, 70, 700) in which doping of facing base (75) and collector (86) regions is arranged so that avalanche breakdown occurs preferentially within a portion (84, 85) of the base region (74, 75) of the device (70, 700) away from the overlying dielectric-semiconductor interface (791). Maximum variations (?Vt1)MAX of ESD triggering voltage Vt1 as a function of base-collector spacing dimensions D due, for example, to different azimuthal orientations of transistors (21, 21?, 70, 700) on a semiconductor die or wafer is much reduced. Triggering voltage consistency and manufacturing yield are improved.

Abstract: Methods for forming an electrostatic discharge protection (ESD) clamps are provided. In one embodiment, the method includes forming at least one transistor having a first well region of a first conductivity type extending into a substrate. At least one transistor is formed having another well region of a second opposite conductivity type, which extends into the substrate to partially form a collector. The lateral edges of the transistor well regions are separated by a distance D, which at least partially determines a threshold voltage Vt1 of the ESD clamp. A base contact of the first conductivity type is formed in the first well region and separated from an emitter of the second conductivity type by a lateral distance Lbe. The first doping density and the lateral distance Lbe are selected to provide a parasitic base-emitter resistance Rbe in the range of 1<Rbe<800 Ohms.

Abstract: An area-efficient, high voltage, dual polarity ESD protection device (200) is provided for protecting multiple pins (30, 40) against ESD events by using a plurality of stacked NPN devices (38, 48, 39) which have separately controllable breakdown voltages and which share one or common NPN devices (39), thereby reducing the footprint of the high voltage ESD protection circuits without reducing robustness and functionality.

Abstract: Methods for forming an electrostatic discharge protection (ESD) clamps are provided. In one embodiment, the method includes forming at least one transistor having a first well region of a first conductivity type extending into a substrate. At least one transistor is formed having another well region of a second opposite conductivity type, which extends into the substrate to partially form a collector. The lateral edges of the transistor well regions are separated by a distance D, which at least partially determines a threshold voltage Vt1 of the ESD clamp. A base contact of the first conductivity type is formed in the first well region and separated from an emitter of the second conductivity type by a lateral distance Lbe.

Abstract: Embodiments include methods for forming an electrostatic discharge (ESD) protection device coupled across input-output (I/O) and common terminals of a core circuit, where the ESD protection device includes first and second merged bipolar transistors. A base of the first transistor serves as collector of the second transistor and the base of the second transistor serves as collector of the first transistor, the bases having, respectively, first and second widths. A first resistance is coupled between an emitter and base of the first transistor and a second resistance is coupled between an emitter and base of the second transistor. ESD trigger voltage Vt1 and holding voltage Vh can be independently optimized by choosing appropriate base widths and resistances. By increasing Vh to approximately equal Vt1, the ESD protection is more robust, especially for applications with narrow design windows, for example, with operating voltage close to the degradation voltage.

Abstract: An electrostatic discharge (ESD) clamp, coupled across input-output (I/O) and common (GND) terminals of a protected semiconductor device or integrated circuit is provided. One ESD clamp comprises an ESD transistor (ESDT) with source-drain coupled between the GND and I/O terminals, a first resistor coupled between the gate and source and a second resistor coupled between the ESDT body and source. Paralleling the resistors are control transistors with gates coupled to one or more bias supplies Vb, Vb?. The main power rail (Vdd) of the device or IC is a convenient source for Vb, Vb?. When the Vdd is off during shipment, handling, equipment assembly, etc., the ESD trigger voltage Vt1 is low, thereby providing maximum ESD protection when ESD risk is high. When Vdd is energized, Vt1 rises to a value large enough to avoid interference with normal circuit operation but still protect from ESD events.

Abstract: A stackable electrostatic discharge (ESD) protection clamp (21) for protecting a circuit core (24) comprises, a bipolar transistor (56, 58) having a base region (74, 51, 52, 85) with a base contact (77) therein and an emitter (78) spaced a lateral distance Lbe from the base contact (77), and a collector (80, 86, 762) proximate the base region (74, 51, 52, 85). The base region (74, 51, 52, 85) comprises a first portion (51) including the base contact (77) and emitter (78), and a second portion (52) with a lateral boundary (752) separated from the collector (86, 762) by a breakdown region (84) whose width D controls the clamp trigger voltage, the second portion (52) lying between the first portion (51) and the boundary (752). The damage-onset threshold current It2 of the ESD clamp (21) is improved by increasing the parasitic resistance Rbe of the emitter-base region (74, 51, 52, 85), by for example, increasing Lbe or decreasing the relative doping density of the first portion (51) or a combination thereof.

Abstract: An area-efficient, high voltage, single polarity ESD protection device (300) is provided which includes an p-type substrate (303); a first p-well (308-1) formed in the substrate and sized to contain n+ and p+ contact regions (310, 312) that are connected to a cathode terminal; a second, separate p-well (308-2) formed in the substrate and sized to contain only a p+ contact region (311) that is connected to an anode terminal; and an electrically floating n-type isolation structure (304, 306, 307-2) formed in the substrate to surround and separate the first and second semiconductor regions. When a positive voltage exceeding a triggering voltage level is applied to the cathode and anode terminals, the ESD protection device triggers an inherent thyristor into a snap-back mode to provide a low impedance path through the structure for discharging the ESD current.

Abstract: An electrostatic discharge (ESD) clamp, coupled across input-output (I/O) and common (GND) terminals of a protected semiconductor device or integrated circuit is provided. One ESD clamp comprises an ESD transistor (ESDT) with source-drain coupled between the GND and I/O terminals, a first resistor coupled between the gate and source and a second resistor coupled between the ESDT body and source. Paralleling the resistors are control transistors with gates coupled to one or more bias supplies Vb, Vb?. The main power rail (Vdd) of the device or IC is a convenient source for Vb, Vb?. When the Vdd is off during shipment, handling, equipment assembly, etc., the ESD trigger voltage Vt1 is low, thereby providing maximum ESD protection when ESD risk is high. When Vdd is energized, Vt1 rises to a value large enough to avoid interference with normal circuit operation but still protect from ESD events.

Abstract: Methods are provided for producing stacked electrostatic discharge (ESD) clamps. In one embodiment, the method includes providing a semiconductor substrate in which first and second serially-coupled transistors are formed. The first transistor includes a first well region having a first lateral edge partially forming the first transistor's base. The second transistor including a second well region having a second lateral edge partially forming the second transistor's base. Third and fourth well regions are formed in the first and second transistors, respectively, and extend a different distance into the substrate than do the well regions of the first and second transistors. The third well region has a third lateral edge separated from the first lateral edge by a first spacing dimension D1. The fourth well region has a fourth lateral edge separated from the second lateral edge by a second spacing dimension D2, which is different than D1.

Abstract: An electrostatic discharge (ESD) clamp (41, 51, 61, 71, 81, 91), coupled across input-output (I/O) (22) and common (GND) (23) terminals of a protected semiconductor SC device or IC (24), comprises, an ESD transistor (ESDT) (25) with source-drain (26, 27) coupled between the GND (23) and I/O (22), a first resistor (30) coupled between gate (28) and source (26) and a second resistor (30) coupled between ESDT body (29) and source (26). Paralleling the resistors (30, 32) are control transistors (35, 35?) with gates (38, 38?) coupled to one or more bias supplies Vb, Vb?. The main power rail (Vdd) of the device or IC (24) is a convenient source for Vb, Vb?. When the Vdd is off during shipment, handling, equipment assembly, etc., the ESD trigger voltage Vt1 is low, thereby providing maximum ESD protection when ESD risk is high. When Vdd is energized, Vt1 rises to a value large enough to avoid interference with normal circuit operation but still protect from ESD events.

Abstract: Embodiments include methods for forming an electrostatic discharge (ESD) protection device coupled across input-output (I/O) and common terminals of a core circuit, where the ESD protection device includes first and second merged bipolar transistors. A base of the first transistor serves as collector of the second transistor and the base of the second transistor serves as collector of the first transistor, the bases having, respectively, first and second widths. A first resistance is coupled between an emitter and base of the first transistor and a second resistance is coupled between an emitter and base of the second transistor. ESD trigger voltage Vt1 and holding voltage Vh can be independently optimized by choosing appropriate base widths and resistances. By increasing Vh to approximately equal Vt1, the ESD protection is more robust, especially for applications with narrow design windows, for example, with operating voltage close to the degradation voltage.

Abstract: A stacked electrostatic discharge (ESD) protection clamp (99, 100-104) for protecting associated devices or circuits (24) comprises two or more series coupled (stacked) bipolar transistors (70, 700) whose individual trigger voltages Vt1 depend on their base-collector spacing D. A first (70-1, 700-1) of the transistors (70, 700) has a spacing DZ1 chosen within a D range Z1 whose slope (?Vt1/?D) has a first value (?Vt1/?D)Z1, and a second (70-2, 700-2) of the transistors (70, 700) has a spacing value D(Z2 or Z3) chosen within a D range Z2 or Z3 whose slope (?Vt1/?D) has a second value (?Vt1/?D)(Z2 or Z3) less than the first value (?Vt1/?D)Z1. The sensitivity of the ESD stack trigger voltage Vt1STACK to base-collector spacing variations ?D during manufacture is much reduced, for example, by as much as 50% for a 2-stack and more for 3-stacks and beyond. A wide range of Vt1STACK values can be obtained that are less sensitive to unavoidable manufacturing spacing variations ?D.

Abstract: An electrostatic discharge (ESD) protection device coupled across input-output (I/O) and common terminals of a core circuit, comprises, first and second merged bipolar transistors. A base of the first transistor serves as collector of the second transistor and the base of the second transistor serves as collector of the first transistor, the bases having, respectively, first width and second width. A first resistance is coupled between an emitter and base of the first transistor and a second resistance is coupled between an emitter and base of the second transistor. ESD trigger voltage Vtl and holding voltage Vh can be independently optimized by choosing appropriate base widths and resistances. By increasing Vh to approximately equal Vtl, the ESD protection is more robust, especially for applications with narrow design windows, for example, with operating voltage close to the degradation voltage.

Abstract: An area-efficient, high voltage, single polarity ESD protection device (300) is provided which includes an p-type substrate (303); a first p-well (308-1) formed in the substrate and sized to contain n+ and p+ contact regions (310, 312) that are connected to a cathode terminal; a second, separate p-well (308-2) formed in the substrate and sized to contain only a p+ contact region (311) that is connected to an anode terminal; and an electrically floating n-type isolation structure (304, 306, 307-2) formed in the substrate to surround and separate the first and second semiconductor regions. When a positive voltage exceeding a triggering voltage level is applied to the cathode and anode terminals, the ESD protection device triggers an inherent thyristor into a snap-back mode to provide a low impedance path through the structure for discharging the ESD current.

Abstract: A stackable electrostatic discharge (ESD) protection clamp (21) for protecting a circuit core (24) comprises, a bipolar transistor (56, 58) having a base region (74, 51, 52, 85) with a base contact (77) therein and an emitter (78) spaced a lateral distance Lbe from the base contact (77), and a collector (80, 86, 762) proximate the base region (74, 51, 52, 85). The base region (74, 51, 52, 85) comprises a first portion (51) including the base contact (77) and emitter (78), and a second portion (52) with a lateral boundary (752) separated from the collector (86, 762) by a breakdown region (84) whose width D controls the clamp trigger voltage, the second portion (52) lying between the first portion (51) and the boundary (752). The damage-onset threshold current It2 of the ESD clamp (21) is improved by increasing the parasitic resistance Rbe of the emitter-base region (74, 51, 52, 85), by for example, increasing Lbe or decreasing the relative doping density of the first portion (51) or a combination thereof.

Abstract: A stacked electrostatic discharge (ESD) protection clamp (99, 100-104) for protecting associated devices or circuits (24) comprises two or more series coupled (stacked) bipolar transistors (70, 700) whose individual trigger voltages Vt1 depend on their base-collector spacing D. A first (70-1, 700-1) of the transistors (70, 700) has a spacing DZ1 chosen within a D range Z1 whose slope (?Vt1/?D) has a first value (?Vt1/?D)Z1, and a second (70-2, 700-2) of the transistors (70, 700) has a spacing value D(Z2 or Z3) chosen within a D range Z2 or Z3 whose slope (?Vt1/?D) has a second value (?Vt1/?D)(Z2 or Z3) less than the first value (?Vt1/?D)Z1. The sensitivity of the ESD stack trigger voltage Vt1STACK to base-collector spacing variations ?D during manufacture is much reduced, for example, by as much as 50% for a 2-stack and more for 3-stacks and beyond. A wide range of Vt1STACK values can be obtained that are less sensitive to unavoidable manufacturing spacing variations ?D.