Revolutional Progress of Silicon Technologies Exhibiting Very High Speed Performance Over a 50-GHz Clock Rate

Abstract

Current silicon technologies are now facing very severe standstill, i.e., the operation speed is strictly limited at a clock rate of about 3.8 GHz due to the limitation of the thinning of the gate insulator film thickness because of its large amount of leakage currents through the current thermal oxide films. This typical disadvantage of current silicon technologies has been completely overcome by introducing the newly developed radical-reaction-based semiconductor manufacturing instead of the current molecule-reaction-based semiconductor manufacturing, i.e., direct nitridation films such as Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> where the gate leakage current through the insulator films has been confirmed to be decreased by a factor of at least three orders of magnitude. The speed performance of silicon large-scale integrations is enhanced to exhibit a clock rate of more than 50 GHz by introducing the balanced complementary MOS on a silicon (551) surface substrate using 3-D-structured MOS transistors, where new key technologies must be introduced, namely: 1) direct nitridation gate insulator film Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3 </sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> for 3-D MOS transistors; 2) atomic-order flat-gate insulator film/silicon interface; 3) drastically decreased series resistance of the source and drain electrodes by a factor of two orders of magnitude; and 4) introduction of the accumulation-mode MOS transistors instead of the inversion-mode MOS transistors