A semiconductor device includes a semiconductor substrate, a body layer, a source region, a drift layer, a drain region, a gate insulating film, and a gate electrode. The semiconductor substrate has an active layer. An element region is included in the active layer and partitioned by a trench isolation portion. The body layer is disposed at a surface layer portion of the active layer. The source region is disposed at a surface layer portion of the body layer. The drift layer is disposed at the surface layer portion of the active layer. The drain region is disposed at a surface layer portion of the drift layer. The gate insulating film is disposed on a surface of the body layer. The gate electrode is disposed on the gate insulating film. One of the source region and the drain region being a high potential region is surrounded by the other one being a low potential region.

The source region, drain region, buried insulating film, gate insulating film, and gate electrode of the semiconductor device are formed in a main surface of a semiconductor substrate. The buried insulating film is buried in a first trench formed between the source and drain regions. The first trench has a first side surface and a first bottom surface. The first side surface faces the source region in a first direction extending from one of the source and drain regions to the other. The first bottom surface is connected to the first side surface and is along the main surface of the semiconductor substrate. A crystal plane of a first surface of the semiconductor substrate, which is the first side surface of the first trench, is (111) plane. A crystal plane of a second surface of the semiconductor substrate, which is the bottom surface of the first trench, is (100) plane.

A semiconductor device includes a P-type body region and an N-type drift region disposed in a substrate; a gate electrode, disposed on the P-type body region and the N-type drift region, including a high concentration doping region and a high resistance region, wherein a dopant concentration of the high concentration doping region is higher than a dopant concentration of the high resistance region; a spacer disposed on a side of the gate electrode; a highly doped source region disposed in the P-type body region; and a highly doped drain region disposed in the N-type body region. The high concentration doping region overlaps the P-type body region, and the high resistance region overlaps the N-type drift region.

The present disclosure introduces a microelectronic device including a source side field plate in a microelectronic device. The microelectronic device may be configured as a metal oxide semiconductor (MOS) transistor, a laterally diffused metal oxide semiconductor (LDMOS) transistor, a drain extended metal oxide semiconductor (DEMOS) transistor, a bipolar junction transistor, a junction field effect transistor, a CMOS transistor, or a gated bipolar device. The source side field plate extends over the source region by a distance which is more than a quarter of the width of the source region. Transistors may suffer from Vt shifts during gate and drain stress over time. The source side field plate reduces the electric field of the transistor near the gate electrode corner on the source side of the transistor. The gate injection current on the source side and electron trapping in the gate oxide thereby reduced which reduces Vt shifts over time.

A circular LDMOS device includes a lower drift layer disposed on a substrate, a drain region disposed on the lower drift layer, a source region having a circular ring shape surrounding the drain region and spaced apart from the drain region, a field insulating layer disposed between the drain region and the source region, and an upper drift layer disposed between the lower drift layer and the field insulating layer and having a conductivity type different from that of the lower drift layer.

A semiconductor integrated circuit includes a high-potential-side circuit region, a high-voltage junction termination structure surrounding the high-potential-side circuit region, and a low-potential-side circuit region surrounding the high-potential-side circuit region via the high-voltage junction termination structure which are integrated into a single chip, and wherein a first distance between a looped well region and a buried layer in a region in which a first contact region is formed is smaller than a second distance between the looped well region and the buried layer in a region in which a carrier reception region is formed.

A MOS transistor structure is provided. The MOS transistor structure includes a semiconductor substrate having an active area including a first edge and a second edge opposite thereto. A gate layer is disposed on the active area of the semiconductor substrate and has a first edge extending across the first and second edges of the active area. A source region having a first conductivity type is in the active area at a side of the first edge of the gate layer and between the first and second edges of the active area. First and second heavily doped regions of a second conductivity type are in the active area adjacent to the first and second edges thereof, respectively, and spaced apart from each other by the source region.

A lateral double-diffused metal-oxide-semiconductor (LDMOS) transistor including a breakdown voltage clamp includes a drain n+ region, a source n+ region, a gate, and a p-type reduced surface field (PRSF) layer including one or more bridge portions. Each of the one or more bridge portions extends below the drain n+ region in a thickness direction. Another LDMOS transistor includes a drain n+ region, a source n+ region, a gate, an n-type reduced surface field (NRSF) layer disposed between the source n+ region and the drain n+ region in a lateral direction, a PRSF layer disposed below the NRSF layer in a thickness direction orthogonal to the lateral direction, and a p-type buried layer (PBL) disposed below the PRSF layer in the thickness direction. The drain n+ region is disposed over the PBL in the thickness direction.

A Laterally Diffused Metal Oxide Semiconductor (LDMOS) transistor with implant alignment spacers includes a gate stack comprising a first nitride layer. The first nitride layer is formed on a silicon layer. The gate stack is separated from a substrate by a first oxide layer. The gate stack includes a polysilicon layer formed from the silicon layer, and a second oxide layer is formed on a sidewall of the polysilicon layer. A drain region of the LDMOS transistor is implanted with a first implant aligned to a first edge formed by the second oxide layer. A second nitride layer conformingly covers the second oxide layer. A nitride etch-stop layer conformingly covers the second nitride layer.

In some embodiments, the present disclosure relates to an integrated chip that includes a source region and a drain region arranged over and/or within a substrate. Further, a shallow trench isolation (STI) structure is arranged within the substrate and between the source and drain regions. A gate electrode is arranged over the substrate, over the STI structure, and between the source and drain regions. A portion of the gate electrode extends into the STI structure such that a bottommost surface of the portion of the gate electrode is arranged between a topmost surface of the STI structure and a bottommost surface of the STI structure.