A LDMOS transistor includes a semiconductor substrate with a first doping type; a plurality of first trenches formed in the semiconductor substrate; a wave-shaped drift region with an increased conductive path and a second doping type formed on the semiconductor substrate between adjacent first trenches and the semiconductor substrate exposed by side and bottom surfaces of the first trenches; a first shallow trench isolation (STI) structure formed in each of the first trenches; a body region with the first doping type formed in semiconductor substrate at one side of the drift region; a gate structure formed over portions of the body region, the drift region and the first STI structure most close to the body region; a source region formed in the body region; and a drain region formed in the drift region at one side of the first STI structure most far away from the body region.

A transistor includes source region and drain regions, a channel region, a drift region, a gate, a dummy gate, a gate dielectric layer and an interconnection line. The source and drain regions of a first conductivity type are in a substrate. The channel region of a second conductivity type is in the substrate and surrounds the source region. The drift region of the first conductivity type is beneath the drain region and extends toward the channel region. The gate is over the substrate and overlapped with the channel region and the drift region. The dummy gate is over the drift region and laterally adjacent to the gate. The gate dielectric layer is between the gate and the substrate and between the dummy gate and the drift region. The interconnection line is electrically connected to the dummy gate and configured to provide a voltage potential thereto.

A laterally diffused MOS (LDMOS) device includes a substrate having a p-epi layer thereon. A p-body region is in the p-epi layer. An ndrift (NDRIFT) region is within the p-body region providing a drain extension region, and a gate dielectric layer is formed over a channel region in the p-body region adjacent to and on respective sides of a junction with the NDRIFT region, and a patterned gate electrode on the gate dielectric. A DWELL region is within the p-body region, sidewall spacers are on sidewalls of the gate electrode, a source region is within the DWELL region, and a drain region is within the NDRIFT region. The p-body region includes a portion being at least one 0.5 m wide that has a net p-type doping level above a doping level of the p-epi layer and a net p-type doping profile gradient of at least 5/m.

A device includes a semiconductor substrate, a buried doped isolation layer disposed in the semiconductor substrate to isolate the device, a drain region disposed in the semiconductor substrate and to which a voltage is applied during operation, and a depletion region disposed in the semiconductor substrate and having a conductivity type in common with the buried doped isolation barrier and the drain region. The depletion region reaches a depth in the semiconductor substrate to be in contact with the buried doped isolation layer. The depletion region establishes an electrical link between the buried doped isolation layer and the drain region such that the buried doped isolation layer is biased at a voltage level lower than the voltage applied to the drain region.

A semiconductor device and the method of manufacturing the same are provided. The semiconductor device includes a substrate, a source region, a drain region, a filed plate and a gate electrode. The source region is of a first conductivity type located at a first side within the substrate. The drain region is of the first conductive type located at a second side within the substrate opposite to the first side. The field plate is located over the substrate and between the source region and the drain region. A portion of the gate electrode is located over the field plate.

The high-voltage transistor device has a p-type semiconductor substrate that is furnished with a p-type epitaxial layer. A well and a body region are located in the epitaxial layer. A source region is arranged in the body region, and a drain region is arranged in the well. A channel region is located in the body region between the well and the source region. A gate electrode is arranged above the channel region. In the part of the semiconductor substrate and the epitaxial layer underneath the source region and the channel region, a deep body region is present, which has a higher dopant concentration in comparison to the remainder of the semiconductor substrate.

A semiconductor device is provided. The semiconductor device comprises a substrate, a gate, a first doped region and a second doped region. The gate is over the substrate. The first doped region and the second doped region are in the substrate. The first doped region and the second doped region are of a same conductivity type and separated by the gate. The length of the first doped region is greater than a length of the second doped region in a direction substantially perpendicular to a channel length defined between the first doped region and the second doped region.

A high voltage DMOS device using conventional silicon BCD (Bipolar CMOS DMOS) technology has a P-type buried layer and an N-type buried layer, a first epitaxial layer and a second epitaxial layer. The high voltage DMOS device is characterized in high breakdown voltage, good robustness and low Ron through controlling the thickness of the epitaxial layers, the dose and forming energy of the buried layers. In addition, the high voltage DMOS may further has a shallow drain region to further improve robustness.

A transistor advantageously embodied in a laterally diffused metal oxide semiconductor device having a gate located over a channel region recessed into a semiconductor substrate and a method of forming the same. In one embodiment, the laterally diffused metal oxide semiconductor device includes a source/drain having a lightly doped region located adjacent the channel region and a heavily doped region located adjacent the lightly doped region. The laterally diffused metal oxide semiconductor device further includes an oppositely doped well located under and within the channel region, and a doped region, located between the heavily doped region and the oppositely doped well, having a doping concentration profile less than a doping concentration profile of the heavily doped region.

A semiconductor variable resistance device includes: a substrate; a gate formed on the substrate, the substrate further including a first trench the first trench formed outside a side of the gate; first and second doped regions, formed in the substrate, the first and second doped regions formed on two sides of the gate, the first trench formed between the gate and the first doped region; and first and second lightly-doped drain (LDD) regions, formed in the substrate. The first LDD region is formed between the first trench and the first doped region. The second LDD region is formed between the gate and the second doped region. The first and second doped regions form a source and a drain, respectively. The first trench is deeper than the first and the second lightly-doped drain regions.