A method for making a field effect transistor includes providing a graphene nanoribbon composite structure. The graphene nanoribbon composite structure includes a substrate and a plurality of graphene nanoribbons spaced apart from each other. The plurality of graphene nanoribbons are located on the substrate and extend substantially along a same direction, and each of the plurality of graphene nanoribbons includes a first end and a second end opposite to the first end. A source electrode is formed on the first end, and a drain electrode is formed on the second end. The source electrode and the drain electrode are electrically connected to the plurality of graphene nanoribbons. An insulating layer is formed on the plurality of graphene nanoribbons, and the plurality of graphene nanoribbons are between the insulating layer and the substrate. A gate is formed on a surface of the insulating layer away from the substrate.

A semiconductor tunnel FET (field effect transistor) including a plurality of nanosheet channels disposed between a first source/drain region and a second source/drain region. The first source/drain region includes a p-type material; and the second source/drain region includes an n-type material.

A method of forming a semiconductor structure includes following operations. A substrate including a silicon (Si) layer is received. An amorphous germanium (Ge) layer is formed on the Si layer. A barrier layer is formed over the amorphous Ge layer. The substrate is annealed to transform the Si layer and the Ge layer to form a single crystalline SiGe layer. A Ge concentration is in a positive correlation with a ratio of a thickness of the Ge layer and a thickness of the Si layer.

A field effect transistor and a preparation method thereof, and a semiconductor structure are provided. An example field effect transistor includes: a substrate structure, a source, a drain, and a gate. The source and the drain are arranged on the substrate structure in a first direction, and a channel region is formed between the source and the drain. A channel layer is formed in the channel region, and N carbon nanotubes extending in the first direction are embedded in the channel layer, where N is an integer greater than or equal to 1. Two ends of each of the N carbon nanotubes are respectively connected to the source and the drain to form a conductive path. The gate is formed on the channel layer. In the channel region between the source and the drain, electron conduction is implemented by using the carbon nanotube disposed in the channel layer.

A method includes the following operations: (i) receiving a FET precursor including a first fin and a second fin, each of the first fin and the second fin having nanowire channels and sacrificial layers; (ii) forming a dummy gate traversing the first and second fins, thereby defining channel regions of the first and second fins under the dummy gate; (iii) forming source/drain features from exposed portions of the first and second fins; (iv) removing the dummy gate to expose the channel regions of the first and second fins; and (v) suspending the nanowire channels of the first and second fins by removing portions of the sacrificial layers of the first and second fins.

A programmable cell includes a semiconductor-on-insulator substrate, a program gate, and a word line gate. The semiconductor-on-insulator substrate includes a semiconductor layer. The semiconductor layer includes a first doped source/drain region, a second doped source/drain region and a region comprising germanium. The program gate is disposed above the region comprising germanium and includes a first gate dielectric layer disposed below a gate conductor. The word line gate is disposed between the first doped source/drain region and the second doped source/drain region.

A semiconductor device may include a substrate including center and edge regions, active patterns on the substrate, channel patterns on the active patterns, source/drain patterns connected to the channel patterns, and gate electrodes on the channel patterns. Each of the source/drain patterns may include a buffer layer in contact with a corresponding one of the channel patterns and a main layer on the buffer layer. The main layer of each of the source/drain patterns may include first and second semiconductor layers, which may be sequentially stacked and contain germanium. A concentration of the germanium in the first semiconductor layer may be higher on the center region than on the edge region, and a concentration of the germanium in the second semiconductor layer may be lower on the center region than on the edge region.

A method of modifying a strain state of a first channel structure in a transistor is provided, said structure being formed from superposed semiconducting elements, the method including providing on a substrate at least one first semiconducting structure formed from a semiconducting stack including alternating elements based on at least one first semiconducting material and elements based on at least one second semiconducting material different from the first material; then removing portions of the second material from the first semiconducting structure by selective etching, the removed portions forming at least one empty space; filling the empty space with a dielectric material; forming a straining zone on the first semiconducting structure based on a first strained material having an intrinsic strain; and performing thermal annealing to cause the dielectric material to creep, and to cause a change in a strain state of the elements based on the first material.

Disclosed herein is a composite transistor which includes a first transistor TR.sub.1 including a control electrode, a first active region, a first A extending part, and a first B extending part, and a second transistor TR.sub.2 including a control electrode, a second active region, a second A extending part, and a second B extending part. The first active region, the second active region, and the control electrode overlap one another. Both the first A extending part and the first B extending part extend from the first active region and both the second A extending part and the second B extending part extend from the second active region. The first electrode is connected to the first A extending part, the second electrode is connected to the second A extending part, and the third electrode is connected to the first B extending part and the second B extending part.

This disclosure relates to forming a wrap-around contact on a nanosheet transistor, the method including: forming an etch-stop layer over a continuous outer surface of a raised source/drain (S/D) region of the nanosheet transistor; forming a sacrificial layer over the etch-stop layer, the etch-stop layer including a different material than the sacrificial layer; depositing a dielectric layer over the sacrificial layer; removing an upper portion of the dielectric layer to expose a portion of the sacrificial layer; removing the sacrificial layer selective to the etch-stop layer; and depositing a conductor in the removed upper portion of the dielectric layer to form a wrap-around contact and a second contact.