Sub-100 nm gate length metal gate NMOS transistors fabricated by a replacement gate process

A novel replacement gate design with 1.5-3 nm oxide or remote plasma nitrided oxide gate insulators for sub-100 nm Al/TiN or W/TiN metal gate nMOSFETs is demonstrated. The source/drain regions are self-aligned to a poly gate which is later replaced by the metal gate. This allows the temperatures after metal gate definition to be limited to 450/spl deg/C. Compared to pure SiO/sub 2/, the nitrided oxides provide increased capacitance with less penalty in increased gate current. A saturation transconductance (g/sub m/) of 1000 mS/mm is obtained for L/sub gate/=70 nm and t/sub OX/=1.5 nm. Peak cutoff frequency (f/sub T/) of 120 GHz and a low minimum noise figure (NF/sub min/) of 0.5 dB with associated gain of 19 dB are obtained for t/sub OX/=2 nm and L/sub gate/=80 nm.