Ultra-thin two-dimensional (2d) nanosheet field effect transistor with middle-of-line copper contacts

A nanosheet field effect transistor (FET) structure, comprising:

• a gate stack comprising:
• interfacial adhesion layers (IALs);
• ultrathin nanosheets comprising a non-silicate material, the ultrathin nanosheets being interleaved with neighboring IAL pairs to form combination layers;
• and
• gate metal layers interleaved with the combination layers;
• first and second contacts comprising metallic material disposed on opposite sides of the gate stack;
• and
• a conformal liner interposed between the gate stack and the first and second contacts,
• the non-silicate material having higher in-plane conductivity than material of the conformal liner, the material of the conformal liner having higher out-of-plane conductivity than the non-silicate material and the material of the conformal liner being capable of preventing diffusion of the metallic material into the non-silicate material.

A method of assembling a nanosheet field effect transistor (FET) structure, the method comprising:

• forming a gate stack on a substrate, the gate stack comprising:
• dielectric layers;
• ultrathin nanosheets comprising a first transition metal dichalcogenide (TMDC), the ultrathin nanosheets being interleaved with neighboring dielectric layer pairs to form combination layers;
• and
• gate metal layers interleaved with the combination layers;
• modifying the gate stack by recessing the dielectric layers and the gate metal layers from opposite ends of the ultrathin nanosheets;
• forming a conformal liner comprising a second TMDC around the gate stack;
• and
• forming copper contacts contacting the conformal liner at opposite sides of the gate stack.