Flexible threshold voltage 4-terminal FinFETs

Four-terminal (4T) FinFETs with independent double gates and an ideal rectangular cross-section Si-fin channel have successfully been fabricated by using newly developed orientation-dependent wet etching. The flexible threshold voltage (V/sub th/) controllability by one of the double gates arid by synchronized driving mode operation is systematically examined for the fabricated 4T-FinFFTs with different silicon (Si)-fin thicknesses (T/sub Si/'s). The experimental results reveal that the thinner T/sub Si/ is effective to accomplish a flexible V/sub th/ tuning. The developed processes are very attractive to the fabrication of the advanced 4T-FinFETs for flexible function VLSI circuits.