A wide band gap semiconductor device includes a semiconductor layer, a trench formed in the semiconductor layer, first, second, and third regions having particular conductivity types and defining sides of the trench, and a first electrode embedded inside an insulating film in the trench. The second region integrally includes a first portion arranged closer to a first surface of the semiconductor layer than to a bottom surface of the trench, and a second portion projecting from the first portion toward a second surface of the semiconductor layer to a depth below a bottom surface of the trench. The second portion of the second region defines a boundary surface with the third region, the boundary region being at an incline with respect to the first surface of the semiconductor layer.

A method includes forming a fin over a substrate, forming an isolation region adjacent the fin, forming a dummy gate structure over the fin, and recessing the fin adjacent the dummy gate structure to form a first recess using a first etching process. The method also includes performing a plasma clean process on the first recess, the plasma clean process including placing the substrate on a holder disposed in a process chamber, heating the holder to a process temperature between 300 C. and 1000 C., introducing hydrogen gas into a plasma generation chamber connected to the process chamber, igniting a plasma within the plasma generation chamber to form hydrogen radicals, and exposing surfaces of the recess to the hydrogen radicals. The method also includes epitaxially growing a source/drain region in the first recess.

Methods of cutting gate structures, and structures formed, are described. In an embodiment, a structure includes first and second gate structures over an active area, and a gate cut-fill structure. The first and second gate structures extend parallel. The active area includes a source/drain region disposed laterally between the first and second gate structures. The gate cut-fill structure has first and second primary portions and an intermediate portion. The first and second primary portions abut the first and second gate structures, respectively. The intermediate portion extends laterally between the first and second primary portions. First and second widths of the first and second primary portions along longitudinal midlines of the first and second gate structures, respectively, are each greater than a third width of the intermediate portion midway between the first and second gate structures and parallel to the longitudinal midline of the first gate structure.

A method includes forming a semiconductor fin over a substrate, etching the semiconductor fin to form a recess, wherein the recess extends into the substrate, and forming a source/drain region in the recess, wherein forming the source/drain region includes epitaxially growing a first semiconductor material on sidewalls of the recess, wherein the first semiconductor material includes silicon germanium, wherein the first semiconductor material has a first germanium concentration from 10 to 40 atomic percent, epitaxially growing a second semiconductor material over the first semiconductor material, the second semiconductor material including silicon germanium, wherein the second semiconductor material has a second germanium concentration that is greater than the first germanium concentration, and epitaxially growing a third semiconductor material over the second semiconductor material, the third semiconductor material including silicon germanium, wherein the third semiconductor material has a third germanium concentration that is smaller than the second germanium concentration.

A semiconductor device with multiple silicide regions is provided. In embodiments a first silicide precursor and a second silicide precursor are deposited on a source/drain region. A first silicide with a first phase is formed, and the second silicide precursor is insoluble within the first phase of the first silicide. The first phase of the first silicide is modified to a second phase of the first silicide, and the second silicide precursor being soluble within the second phase of the first silicide. A second silicide is formed with the second silicide precursor and the second phase of the first silicide.

The present disclosure provides an integrated circuit device that comprises a semiconductor substrate having a top surface; a first and a second source/drain features over the semiconductor substrate; a first semiconductor layer extending in parallel with the top surface and connecting the first and the second source/drain features, the first semiconductor layer having a center portion and two end portions, each of the two end portions connecting the center portion and one of the first and second source/drain features; a first spacer over the two end portions of the first semiconductor layer; a second spacer vertically between the two end portions of the first semiconductor layer and the top surface; and a gate electrode wrapping around and engaging the center portion of the first semiconductor layer. The center portion has a thickness smaller than the two end portions.

A semiconductor device includes a semiconductor fin, a gate structure, source/drain structures, and a contact structure. The semiconductor fin extends from a substrate. The gate structure extends across the semiconductor fin. The source/drain structures are on opposite sides of the gate structure. The contact structure is over a first one of the source/drain structures. The contact structure includes a semiconductor contact and a metal contact over the semiconductor contact. The semiconductor contact has a higher dopant concentration than the first one of the source/drain structures. The first one of the source/drain structures includes a first portion and a second portion at opposite sides of the fin and interfacing the semiconductor contact.

There is provided a semiconductor device including: a semiconductor substrate; a gate insulating film provided on the semiconductor substrate; a gate electrode layer that is provided on the gate insulating film and contains impurity ions; and source or drain regions that are provided on the semiconductor substrate on both sides of the gate electrode layer and contain conductive impurities, in which a concentration of the impurity ions in the gate electrode layer is higher than concentrations of the conductive impurities in the source or drain regions.

A semiconductor device including a gate structure on a channel region portion of a fin structure, and at least one of an epitaxial source region and an epitaxial drain region on a source region portion and a drain region portion of the fin structure. At least one of the epitaxial source region portion and the epitaxial drain region portion include a first concentration doped portion adjacent to the fin structure, and a second concentration doped portion on the first concentration doped portion. The second concentration portion has a greater dopant concentration than the first concentration doped portion. An extension dopant region extending into the channel portion of the fin structure having an abrupt dopant concentration gradient of n-type or p-type dopants of 7 nm per decade or greater.

To improve withstand capability of a semiconductor device during reverse recovery, provided is a semiconductor device including a semiconductor substrate having a first conduction type; a first region having a second conduction type that is formed in a front surface of the semiconductor substrate; a second region having a second conduction type that is formed adjacent to the first region in the front surface of the semiconductor substrate and has a higher concentration than the first region; a third region having a second conduction type that is formed adjacent to the second region in the front surface of the semiconductor substrate and has a higher concentration than the second region; an insulating film that covers a portion of the second region and the third region; and an electrode connected to the second region and the first region that are not covered by the insulating film.