The present disclosure provides semiconductor devices and methods of forming the same. A semiconductor device of the present disclosure includes a first source/drain feature and a second source/drain feature over a substrate, a plurality of channel members extending between the first source/drain feature and the second source/drain feature, a gate structure wrapping around each of the plurality of channel members, and at least one blocking feature. At least one of the plurality of channel members is isolated from the first source/drain feature and the second source/drain feature by the at least one blocking feature.

It is an object to provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a semiconductor device including an inverted staggered thin film transistor whose semiconductor layer is an oxide semiconductor layer, a buffer layer is provided over the oxide semiconductor layer. The buffer layer is in contact with a channel formation region of the semiconductor layer and source and drain electrode layers. A film of the buffer layer has resistance distribution. A region provided over the channel formation region of the semiconductor layer has lower electrical conductivity than the channel formation region of the semiconductor layer, and a region in contact with the source and drain electrode layers has higher electrical conductivity than the channel formation region of the semiconductor layer.

A memory cell includes a transistor and a capacitor. The transistor includes a gate electrode, a gate dielectric disposed over the gate electrode, a channel feature disposed over the gate dielectric and overlapping the gate electrode, a source electrode disposed over the channel feature and electrically connected to the capacitor, and two drain electrodes disposed over the channel feature. The drain electrodes are disposed at opposite sides of the source electrode. The channel feature has a first channel portion extending between and interconnecting one drain electrode and the source electrode, and a second channel portion extending between and interconnecting the other drain electrode and the source electrode. The gate electrode overlaps both of the first channel portion and the second channel portion of the channel feature.

A semiconductor device includes a transistor. The transistor includes a gate electrode, a channel layer, a gate dielectric layer, a first source/drain region and a second source/drain region and a first spacer. The channel layer is disposed on the gate electrode. The gate dielectric layer is located between the channel layer and the gate electrode. The first source/drain region and the second source/drain region are disposed on the channel layer at opposite sides of the gate electrode, and at least one of the first and second source/drain regions includes a first portion and a second portion between the first portion and the gate electrode. The first spacer is disposed on the channel layer. The first spacer is disposed on a first sidewall of the second portion of the at least one of the first and second source/drain regions, and the first portion is disposed on the first spacer.

To further reduce contact resistance when a current or a voltage is taken out from a metal layer. A conductive structure including: an insulating layer; a metal layer provided on one surface of the insulating layer to protrude in a thickness direction of the insulating layer; and a two-dimensional material layer provided along outer shapes of the metal layer and the insulating layer from a side surface of the metal layer to the one surface of the insulating layer.

A semiconductor device includes a substrate, a device isolation layer on the substrate, the device isolation layer defining a first active pattern, a pair of first source/drain patterns on the first active pattern, the pair of first source/drain patterns being spaced apart from each other in a first direction, and each of the pair of first source/drain patterns having a maximum first width in the first direction, a first channel pattern between the pair of first source/drain patterns, a gate electrode on the first channel pattern and extends in a second direction intersecting the first direction, and a first amorphous region in the first active pattern, the first amorphous region being below at least one of the pair of first source/drain patterns, and having a maximum second width in the first direction that is less than the maximum first width.

A semiconductor device including at least one nanosheet and epitaxial source and drain regions are present on opposing ends of the at least one nanosheet. A gate structure is present on a channel of the at least one nanosheet. The gate structure includes a first work function metal gate portion present at a junction portion of the source and drain regions that interfaces with the channel portion of the at least one nanosheet, and a second work function metal gate portion present on a central portion of the channel of the at least one nanosheet. The amount of metal containing nitride in the second work function metal gate portion is greater than an amount of metal containing nitride in the first work function metal gate portion. The device further includes a rotated T-shaped dielectric spacer present between the gate structure and the epitaxial source and drain regions.

A method of fabricating a semiconductor device is described. The method includes forming a nanosheet stack on a substrate, the nanosheet stack includes nanosheet channel layers. A gate is formed around the nanosheet channel layers of the nanosheet stack. A strained material is formed along a sidewall surface of the gate. The strained material is configured to create strain in the nanosheet channel layers of the nanosheet stack.

A semiconductor device includes a substrate, a gate structure, a source region, a drain region, a doped region, and a channel region. The gate structure is disposed in the substrate, and the source region and drain regions being a first conductivity type respectively disposed at two sides of the gate structure. The doped region being a second conductivity type different from the first conductivity type is disposed below and separated from the gate structure, the source region, and drain region, the doped region. The channel region is disposed between the doped region and the gate structure and in contact with the doped region, and a dopant concentration of the channel region is less than a dopant concentration of the doped region.

A semiconductor device includes a substrate; a fin protruding above the substrate, the fin including a compound semiconductor material that includes a semiconductor material and a first dopant, the first dopant having a different lattice constant than the semiconductor material, where a concentration of the first dopant in the fin changes along a first direction from an upper surface of the fin toward the substrate; a gate structure over the fin; a channel region in the fin and directly under the gate structure; and source/drain regions on opposing sides of the gate structure, the source/drain regions including a second dopant, where a concentration of the second dopant at a first location within the channel region is higher than that at a second location within the channel region, where the concentration of the first dopant at the first location is lower than that at the second location.