A semiconductor device includes a deep well region located on a substrate, a drift region located in the deep well region, a first gate electrode that overlaps with the first body region and the drift region, a second gate electrode that overlaps with the second body region and the drift region, a first source region and a second source region located in the first and second body regions, respectively, a drain region located in the drift region and disposed between the first gate electrode and the second gate electrode, a silicide layer located on the substrate, a first non-silicide layer located between the drain region and the first gate electrode, wherein the first non-silicide layer extends over a top surface of the first gate electrode, and a first field plate contact plug in contact with the first non-silicide layer.

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.

The present disclosure provides one embodiment of a semiconductor structure. The semiconductor structure includes a substrate having a front side and a back side; a gate stack formed on the front side of the substrate and disposed on an active region of the substrate; a first source/drain feature formed on the active region and disposed at an edge of the gate stack; a backside power rail formed on the back side of the substrate; and a backside contact feature interposed between the backside power rail and the first source/drain feature, and electrically connecting the backside power rail to the first source/drain feature. The backside contact feature further includes a first silicide layer on the back side of the substrate.

Provided is a semiconductor device whose performance is improved. A p type body region is formed in an n type semiconductor layer containing silicon carbide, and a gate electrode is formed on the body region with a gate insulating film interposed therebetween. An n type source region is formed in the body region on a side surface side of the gate electrode, and the body region and a source region are electrically connected to a source electrode. A p type field relaxation layer FRL is formed in the semiconductor layer on the side surface side of the gate electrode, and the source electrode is electrically connected to the field relaxation layer FRL. The field relaxation layer FRL constitutes a part of the JFET 2Q which is a rectifying element, and a depth of the field relaxation layer FRL is shallower than a depth of the body region.

A semiconductor device, such as a laterally diffused metal-oxide-semiconductor (LDMOS) transistor, includes a semiconductor substrate in which a source region and a drain region are disposed. The drain region has a drain finger terminating at a drain end. A gate structure is supported by the semiconductor substrate between the source region and the drain region, the gate structure extending laterally beyond the drain end. A drift region in the semiconductor substrate extends laterally from the drain region to at least the gate structure. The drift region is characterized by a first distance between a first sidewall of the drain finger and a second sidewall of the gate structure, and the gate structure is laterally tilted away from the drain region at the drain end of the drain finger to a second distance that is greater than the first distance.

The embodiments herein relate to field-effect transistors (FETs) with a gate structure in a dual-depth trench isolation structure and methods of forming the same. The FET includes a substrate having an upper surface, a trench isolation structure, and a gate structure adjacent to the trench isolation structure. The trench isolation structure has a first portion having a lower surface and a second portion having a lower surface in the substrate; the lower surface of the first portion is above the lower surface of the second portion.

A silicon carbide semiconductor device includes a silicon carbide substrate, a first electrode, and a second electrode. The silicon carbide substrate has a first main surface, a second main surface, a first impurity region, a second impurity region, and a third impurity region. The first electrode is in contact with each of the second impurity region and the third impurity region on the first main surface. The second electrode is in contact with the first impurity region on the second main surface. The second impurity region includes a first region and a second region disposed between the first region and the second main surface and in contact with the first region. An impurity concentration of the first region is more than or equal to 6×10.sup.16 cm.sup.−3.

The present disclosure provides one embodiment of a semiconductor structure. The semiconductor structure includes a substrate having a front side and a back side; a gate stack formed on the front side of the substrate and disposed on an active region of the substrate; a first source/drain feature formed on the active region and disposed at an edge of the gate stack; a backside power rail formed on the back side of the substrate; and a backside contact feature interposed between the backside power rail and the first source/drain feature, and electrically connecting the backside power rail to the first source/drain feature. The backside contact feature further includes a first silicide layer on the back side of the substrate and directly contacting a bottom surface of the first source/drain feature.

A method for forming a superjunction power semiconductor device includes forming multiple epitaxial layers of a first conductivity type on a semiconductor substrate and implanting dopants of a second conductivity type into each epitaxial layer to form a first group of implanted regions in a first region and a second group of implanted regions in a second region in each epitaxial layer. The multiple epitaxial layers are annealed to form multiple columns of the second conductivity type having slanted sidewalls across the first to last epitaxial layers. The columns include a first group of columns formed by the implanted regions of the first group and having a first grading and a second group of columns formed by the implanted regions of the second group and having a second grading, where the second grading is less than the first grading.