A method and structures are used to fabricate a nanosheet semiconductor device. Nanosheet fins including nanosheet stacks including alternating silicon (Si) layers and silicon germanium (SiGe) layers are formed on a substrate and etched to define a first end and a second end along a first axis between which each nanosheet fin extends parallel to every other nanosheet fin. The SiGe layers are undercut in the nanosheet stacks at the first end and the second end to form divots, and a dielectric is deposited in the divots. The SiGe layers between the Si layers are removed before forming source and drain regions of the nanosheet semiconductor device such that there are gaps between the Si layers of each nanosheet stack, and the dielectric anchors the Si layers. The gaps are filled with an oxide that is removed after removing the dummy gate and prior to forming the replacement gate.

A device includes a fin extending from a semiconductor substrate, a gate stack over and along a sidewall of the fin, an isolation region surrounding the gate stack, an epitaxial source/drain region in the fin and adjacent the gate stack, and a source/drain contact extending through the isolation region, including a first silicide region in the epitaxial source/drain region, the first silicide region including NiSi.sub.2, a second silicide region on the first silicide region, the second silicide region including TiSi.sub.x, and a conductive material on the second silicide region.

In an embodiment, a device includes: a semiconductor substrate; a first fin extending from the semiconductor substrate; a second fin extending from the semiconductor substrate; an epitaxial source/drain region including: a main layer in the first fin and the second fin, the main layer including a first semiconductor material, the main layer having an upper faceted surface and a lower faceted surface, the upper faceted surface and the lower faceted surface each being raised from respective surfaces of the first fin and the second fin; and a semiconductor contact etch stop layer (CESL) contacting the upper faceted surface and the lower faceted surface of the main layer, the semiconductor CESL including a second semiconductor material, the second semiconductor material being different from the first semiconductor material.

The present application discloses a semiconductor transistor structure, which includes: a substrate formed with a well region of a first conductive type, a gate structure being disposed on the substrate; a source/drain region of a second conductive type disposed in the well region of the first conductive type, the source region and the drain region being located on two sides of the gate structure respectively; a contact hole formed at a position corresponding to the source/drain region; and a conductive metal filled in the contact hole, the bottom of the contact hole being implanted with impurity ions for decreasing the contact resistance of the contact hole, and the impurity ion concentration at a peripheral region where the bottom of the contact hole comes into contact with the source/drain region being lower than the impurity ion concentration at a middle region.

Confined epitaxial regions for semiconductor devices and methods of fabricating semiconductor devices having confined epitaxial regions are described. For example, a semiconductor structure includes a plurality of parallel semiconductor fins disposed above and continuous with a semiconductor substrate. An isolation structure is disposed above the semiconductor substrate and adjacent to lower portions of each of the plurality of parallel semiconductor fins. An upper portion of each of the plurality of parallel semiconductor fins protrudes above an uppermost surface of the isolation structure. Epitaxial source and drain regions are disposed in each of the plurality of parallel semiconductor fins adjacent to a channel region in the upper portion of the semiconductor fin. The epitaxial source and drain regions do not extend laterally over the isolation structure. The semiconductor structure also includes one or more gate electrodes, each gate electrode disposed over the channel region of one or more of the plurality of parallel semiconductor fins.

A member includes a buffer layer made of GaN. The member is characterized in that the member includes a source layer arranged on top of the buffer layer, and the source layer made of n-doped GaN. The member includes a first barrier layer made of AlGaN arranged over the buffer layer and a first gate layer made of p-doped GaN arranged over the first barrier layer, where the first barrier layer and the first gate layer are arranged adjacent the source layer on one side. The member includes a second barrier layer made of AlGaN arranged over the buffer layer and a second gate layer made of p-doped GaN arranged over the second barrier layer, where the second barrier layer and the second gate layer are arranged adjacent the source layer on another side. The member enables an independent optimization of the two-dimensional electron gas characteristics and the threshold voltage.

The present application discloses a semiconductor device and a method for fabricating the semiconductor device. The semiconductor device includes a substrate; a bottom conductive region positioned in the substrate; a first gate structure positioned on the substrate; a first drain region positioned in the substrate and adjacent to one sidewall of the first gate structure; and a first extended conductive region positioned in the substrate, under the first drain region, contacting a bottom surface of the first drain region, and distant from the bottom conductive region. A top surface of the first drain region and a top surface of the substrate are substantially coplanar. The bottom conductive region and the first extended conductive region include the same electrical type. The first drain region and the first extended conductive region include different electrical types.

A semiconductor device is provided including an active pattern disposed on a substrate, a source/drain pattern on the active pattern, a channel pattern configured to electrically connect the source/drain patterns and including stacked semiconductor patterns spaced apart from each other in a first direction perpendicular to an upper surface of the substrate, a gate pattern configured to cross between the source/drain patterns in a second direction parallel to the upper surface of the substrate, on the channel pattern, and to have a main gate portion and sub-gate portions, and inner gate spacers between the sub-gate portions and the source/drain pattern. A first distance between adjacent source/drain patterns along a given one of the sub-gate portions in the second direction is greater than a second distance between adjacent source/drain patterns passing through the semiconductor patterns in the second direction.

A semiconductor device includes a substrate. An active pattern extends in a first horizontal direction on the substrate. First to third nanosheets are sequentially spaced apart from each other in a vertical direction on the active pattern. A gate electrode extends in a second horizontal direction on the active pattern and surrounds the first to third nanosheets. A source/drain region includes a first layer disposed along side walls and a bottom surface of a source/drain trench and a second layer filling the source/drain trench. The second layer includes a first lower side wall facing a side wall of the first nanosheet and an opposite second lower side wall. A lower surface connects the first and second lower side walls and extends in the first horizontal direction. The first and second lower side walls of the second layer extend to have a constant slope in opposite directions to each other.

A semiconductor device and a manufacturing method of the semiconductor device are provided. The semiconductor device includes a source region, a drain region, a channel region and a plurality of fins. The channel region is located between the source region and the drain region, and the fins pass through the source region, the drain region and the channel region, wherein a number of the fins located in the source region and the drain region and a number of the fins located in the channel region are not equal.