Fabrication of vertical C-shaped-channel nanosheet FETs with source/drain doped by solid-state source diffusion and influence of device dimensions on the on-state current

In this paper, we successfully fabricated a vertical C-shaped nanosheet field-effect transistor with source/drain doping through solid-state source diffusion (SSD-VCNFET), featured by single-crystal silicon channel and self-aligned high-κ metal gate (HKMG). The fabricated SSD-VCNFETs exhibit excellent short-channel control characteristics, with subthreshold swing (SS) of 61 mV/dec, drain-induced barrier lowering (DIBL) of 9.5 mV/V, and high Ion/Ioff ratio of 2.0×108, demonstrating the feasibility of solid-state diffusion for doping in three-dimensional structures. However, the normalized on-state current Ion only reached 5.9 μA/μm. Finally, the influence of device dimensions on the Ion was investigated, and enlarging the area of drain contact was proposed to enhance performance.