Counter doping into uniformly and heavily doped channel region of sub-0.1 μm SOI MOSFETs

We proposed counter doping into a heavily and uniformly doped channel region of SOI MOSFETs. This enabled us to suppress the short channel effects with proper threshold voltage V/sub th/ and to eliminate parasitic edge or back gate transistors. We derived a model for V/sub th/ as a function of the projected range, Rp and dose, /spl Phi//sub D/, of the counter doping, and showed that V/sub th/ is invariable even when the as-implanted counter doping profile redistributes. Using this technology, we demonstrated a V/sub th/ roll-off free 0.075 μm-L/sub Geff/ nMOSFET with low off-state current.