A semiconductor device includes a semiconductor film and a gate structure on the semiconductor film. The gate structure includes a multi-stepped gate dielectric on the semiconductor film and a gate electrode on the multi-stepped gate dielectric. The multi-stepped gate dielectric includes a first gate dielectric segment having a first thickness and a second gate dielectric segment having a second thickness that is less than the first thickness.

A high voltage transistor structure including a substrate, a first isolation structure, a second isolation structure, a gate structure, a first source and drain region, and a second source and drain region is provided. The first isolation structure and the second isolation structure are disposed in the substrate. The gate structure is disposed on the substrate, at least a portion of the first isolation structure, and at least a portion of the second isolation structure. The first source and drain region and the second source and drain region are located in the substrate on two sides of the first isolation structure and the second isolation structure. The depth of the first isolation structure is greater than the depth of the second isolation structure.

A semiconductor device includes a semiconductor layer, a drift region, a source area, a well region, a drain area, and a dielectric film. The drift region and the source area are formed in the semiconductor layer. The well region is formed in the semiconductor layer and between the drift region and the source area. The drain area is formed in the drift region. The dielectric film is formed in the drift region and is located between the source area and the drain area. The dielectric film includes a proximate end portion and a distal end portion which are proximate to and distal from the source area, respectively, and which are asymmetrical to each other.

A power device includes: a semiconductor layer, a well region, a body region, a gate, a source, a drain, a first salicide block (SAB) layer and a second SAB layer. The first SAB layer is formed on a top surface of the semiconductor layer, and is located between the gate and the drain, wherein a part of the well is located vertically below and in contact with the first SAB layer. The second SAB layer is formed vertically above and in contact with the first SAB layer.

A power device includes: a semiconductor layer, a well region, a body region, a gate, a source, a drain, a field oxide region, and a self-aligned drift region. The field oxide region is formed on an upper surface of the semiconductor layer, wherein the field oxide region is located between the gate and the drain. The field oxide region is formed by steps including a chemical mechanical polish (CMP) process step. The self-aligned drift region is formed in the semiconductor layer, wherein the self-aligned drift region is entirely located vertically below and in contact with the field oxide region.

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 semiconductor device can include: a substrate having a first doping type; a first well region located in the substrate and having a second doping type, where the first well region is located at opposite sides of a first region of the substrate; a source region and a drain region located in the first region, where the source region has the second doping type, and the drain region has the second doping type; and a buried layer having the second doping type located in the substrate and below the first region, where the buried layer is incontact with the first well region, where the first region is surrounded by the buried layer and the first well region, and the first doping type is opposite to the second doping type.

Integrated circuits, such as power amplifier integrated circuits, are disclosed containing compact-footprint, vertically-integrated capacitor-avalanche diode (AD) structures. In embodiments, the integrated circuit includes a semiconductor substrate, a metal layer system, and a vertically-integrated capacitor-AD structure. The metal layer system includes, in turn, a body of dielectric material in which a plurality of patterned metal layers are located. The vertically-integrated capacitor-AD structure includes a first AD formed, at least in part, by patterned portions of the first patterned metal layer. A first metal-insulator-metal (MIM) capacitor is also formed in the metal layer system and at least partially overlaps with the first AD, as taken along a vertical axis orthogonal to the principal surface of the semiconductor substrate. In certain instances, at least a majority, if not the entirety of the first AD vertically overlaps with the first MIM capacitor, by surface area, as taken along the vertical axis.

A semiconductor device includes a switch element having a surface and first and second regions and including a first semiconductor material having a band-gap. The first region of the switch element is coupled to a source contact. A floating electrode has first and second ends. The first end of the floating electrode is coupled to the second region of the switch element. A voltage-support structure includes a second semiconductor material having a band-gap that is larger than the band-gap of the first semiconductor material. The voltage-support structure is in contact with the second end of the floating electrode. A drain contact is coupled to the voltage-support structure.

A high voltage transistor structure including a substrate, a first drift region, a second drift region, a first cap layer, a second cap layer, a gate structure, a first source and drain region, and a second source and drain region is provided. The first and second drift regions are disposed in the substrate. The first and second cap layers are respectively disposed on the first and second drift regions. The gate structure is disposed on the substrate and located over at least a portion of the first drift region and at least a portion of the second drift region. The first and second source and drain regions are respectively disposed in the first and second drift regions and located on two sides of the gate structure. The size of the first drift region and the size of the second drift region are asymmetric.