摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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
摘要:
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.
摘要:
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.
摘要:
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
摘要:
An electrostatic discharge (ESD) protection device (11, 60, 80) coupled across input-output (I/O) (22) and common (23) terminals of a core circuit (24), comprises, first (70, 90) and second (72, 92) merged bipolar transistors (70, 90; 72, 92). A base (62, 82) of the first (70, 90) transistor serves as collector of the second transistor (72, 92) and the base of the second transistor (72, 92) serves as collector of the first (70, 90) transistor, the bases (62, 82) having, respectively, first width (74, 94) and second width (76, 96). A first resistance (78, 98) is coupled between an emitter (67, 87) and base (62, 82) of the first transistor (70, 90) and a second resistance (79, 99) is coupled between an emitter (68, 88) and base (64, 42) of the second transistor (92, 92). ESD trigger voltage Vt1 and holding voltage Vh can be independently optimized by choosing appropriate base widths (74, 94; 76, 96) and resistances (78, 98; 79, 99). 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).
摘要:
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.