An interconnection structure, along with methods of forming such, are described. The structure includes a first conductive feature having a two-dimensional material layer, a second conductive feature disposed over the first conductive feature, and a dielectric material disposed adjacent the first and second conductive features. The dielectric material extends from a level of a bottom of the first conductive feature to a level of a top of the second conductive feature.

Barrier-free interconnects and methods of fabrication thereof are disclosed herein. An exemplary interconnect structure has a conductive line disposed over a conductive via. The conductive line has a first conductive plug disposed in a first dielectric layer, and the first conductive plug includes an electrically conductive non-metal material, such as graphite. The conductive via includes a second conductive plug disposed in a second dielectric layer, and the second conductive plug includes a metal material, such as tungsten, ruthenium, molybdenum, or combinations thereof. The first conductive plug physically contacts the second conductive plug and the second dielectric layer. The second conductive plug physically contacts the second dielectric layer. Spacers (which are insulators) may be disposed between sidewalls of the first conductive plug and the first dielectric layer. The spacers may further be disposed between the first dielectric layer and the second dielectric layer.

An MLG (multilayer graphene) device layer structure is connected with a via. The structure includes an M1 MLG interconnect device layer upon a dielectric layer. Interlayer dielectric isolates the M1 MLG interconnect device layer. An M2 MLG interconnect device layer is upon the interlayer dielectric. A metal via penetrates through the M2 MLG interconnect device layer, the interlayer dielectric and the M1 MLG interconnect device layer and makes edge contact throughout the thickness of both M1 MLG and M2 MLG layers. A method diffuses carbon from a solid phase graphene precursor through a catalyst layer to deposit MLG on a dielectric or metal layer via application of mechanical pressure at a diffusion temperature to form MLG layers.

A semiconductor structure includes a semiconductor substrate, a dielectric layer, a via, a first graphene layer, and a metal line. The dielectric layer is over the semiconductor substrate. The via extends through the dielectric layer. The first graphene layer extends along a top surface of the via. The metal line spans the first graphene layer. The metal line has a line width decreasing as a distance from the first graphene layer increases.

A method for manufacturing a semiconductor element includes a preparation step, a protective gas introduction step, a reaction gas introduction step, and a deposition step. Firstly, a semiconductor sample is prepared on a stage of a cavity, where a line width of a circuit pattern layer of the semiconductor sample is less than 100 nm. Then, the stage is heated to and maintained at 250 C. to 480 C., and plasma is activated in a protective atmosphere to crack introduced benzene vapor to form a graphene layer on the circuit pattern layer, where a thickness of the graphene layer is 0.3 nm to 4.5 nm. The reaction can be carried out at a low temperature using the benzene vapor as a carbon source, improving properties of graphene deposited on a surface of the circuit pattern layer, and greatly reducing resistance of the circuit pattern layer.