Vertical MOS Transistors with 70nm Channel Length

Vertical nMOS transistors with channel lengths down to 70nm and thin gate oxides have been fabricated using LPCVD epitaxy for the definition of the channel region instead of fine line lithography. The devices show drain current and transconductance values comparable to very advanced planar transistors. For the shortest channel length a stronger increase of current is observed and is attributed to ballistic and floating substrate effects. Besides high saturation currents due to very short channel lengths a higher integration density seems to be feasible using this vertical transistor technology.