A silicon controlled rectifier including a semiconductor substrate, first and second semiconductor wells, first and second semiconductor regions, third and fourth semiconductor regions and a silicide layer is provided. The first and the second semiconductor wells are formed in the semiconductor substrate. The first and the second semiconductor regions are respectively formed in the first and the second semiconductor wells in spaced apart relation. The third and the fourth semiconductor regions are respectively formed in the first and the second semiconductor wells. The silicide layer is formed on the third and the fourth semiconductor regions. The silicon controlled rectifier is at least suitable for high frequency circuit application. The silicon controlled rectifier has a relatively low trigger voltage, a relatively high electrostatic discharge level, and a relatively low capacitance.

An ESD protection semiconductor device includes a substrate, a first isolation structure disposed in the substrate, a gate disposed on the substrate and overlapping a portion of the first isolation structure, a source region formed in the substrate at a first side of the gate, and a drain region formed in the substrate at a second side of the gate opposite to the first side. The substrate and the drain region include a first conductivity type, the source region includes a second conductivity type, and the first conductivity and the second conductivity type are complementary to each other.

A triac has a vertical structure formed from a silicon substrate having an upper surface side. A main metallization on the upper surface side has a first portion resting on a first region of a first conductivity type formed in a layer of a second conductivity type. A second portion of the main metallization rests on a portion of the layer. A gate metallization on the upper surface side rests on a second region of the first conductivity type formed in the layer in the vicinity of the first region. A porous silicon bar formed in the layer at the upper surface side has a first end in contact with the gate metallization and a second end in contact with the main metallization.

A triac has a vertical structure formed from a silicon substrate having an upper surface side. A main metallization on the upper surface side has a first portion resting on a first region of a first conductivity type formed in a layer of a second conductivity type. A second portion of the main metallization rests on a portion of the layer. A gate metallization on the upper surface side rests on a second region of the first conductivity type formed in the layer in the vicinity of the first region. A porous silicon bar formed in the layer at the upper surface side has a first end in contact with the gate metallization and a second end in contact with the main metallization.

In one aspect, a silicon-controlled rectifier (SCR) includes a Zener diode embedded in the SCR. In another aspect, a laterally diffused metal oxide semiconductor (LDMOS) includes a Zener diode embedded in the LDMOS. In a further aspect, a lateral insulated-gate bipolar transistor (IGBT) includes a Zener diode embedded in the IGBT.

An electrostatic discharge protection structure includes: substrate of a first type of conductivity, well region of a second type of conductivity, substrate contact region in the substrate and of the first type of conductivity, well contact region in the well region and of the second type of conductivity, substrate counter-doped region between the substrate contact region and the well contact region and of the second type of conductivity, well counter-doped region between the substrate contact region and the well contact region and of the first type of conductivity, communication region at a lateral junction between the substrate and the well region, first isolation region between the substrate counter-doped region and the communication region, second isolation region between the well counter-doped region and the communication region, oxide layer having one end on the first isolation region and another end on the substrate, and field plate structure on the oxide layer.

An electrostatic discharge protection structure includes: substrate of a first type of conductivity, well region of a second type of conductivity, substrate contact region in the substrate and of the first type of conductivity, well contact region in the well region and of the second type of conductivity, substrate counter-doped region between the substrate contact region and the well contact region and of the second type of conductivity, well counter-doped region between the substrate contact region and the well contact region and of the first type of conductivity, communication region at a lateral junction between the substrate and the well region, first isolation region between the substrate counter-doped region and the communication region, second isolation region between the well counter-doped region and the communication region, oxide layer having one end on the first isolation region and another end on the substrate, and field plate structure on the oxide layer.

The SCR-based ESD device has a 4-layered PNPN structure (NPN and PNP junction transistors) disposed in SOI having first and second device wells (N-well and P-well) abut forming a NP junction near a midline. First and second contact regions disposed in device wells are coupled to high and low power sources (I/O pad and ground). Internal isolation regions (shallower STI) extending partially not touching the bottom of surface substrate separate the first and second contact regions. A vertical gate is disposed over the NP junction or over a shallower STI which overlaps the NP junction and separate the second contact regions in x-direction. One or more horizontal gates separate the second contact regions in y-direction and guide the device wells underneath the shallower STI to outer edges to connect with the first contact regions for body contacts. A process for forming the device is also disclosed and is compatible with CMOS processes.

A self-balanced silicon-controlled rectification device includes a substrate, an N-type doped well, a P-type doped well, at least one heavily doped clamping fin, at least one first P-type heavily doped fin, and at least one first N-type heavily doped fin. The N-type doped well and the P-type doped well are arranged in the substrate. The heavily doped clamping fin is arranged in the N-type doped well and the P-type well and protruded up from a surface of the substrate. The first P-type heavily doped fin and the first N-type heavily doped fin are respectively arranged in the N-type doped well and the P-type doped well, and protruded up from the surface of the substrate. The abovementioned elements forms silicon-controlled rectifiers (SCRs) are forward biased to generate uniform electrostatic discharge (ESD) currents through the SCRs.

The disclosure relates to a controller (606) for a switched mode power supply, SMPS (600), comprising: a switch toggling unit (670) having a first switching mode and a second switching mode, wherein the first switching mode is a continuous conduction mode or a boundary conduction mode and the second conduction mode is a discontinuous conduction mode; and a switch mode selector (676) configured to set the switching mode of the switch toggling unit (670) in accordance with a current in an inductor (602) of the SMPS (600).