Reliable tantalum-gate fully-depleted-SOI MOSFET technology featuring low-temperature processing

A reliable tantalum (Ta)-gate device technology, which can drastically reduce the number of process steps, has been developed, Ta-gate fully-depleted-silicon-on-insulator (FDSOI) MOSFET's with 0.15-mu m gate length by low-temperature processing below 500 degrees C after the gate oxide formation have good on/off characteristics. Comprehensive design guidelines for Ta-gate MOSFET's in the deep-submicrometer regime is provided by investigating a wide range of performance and reliability constraints on the process temperature and the SOI thickness, In the guideline, the recrystallization of the source/drain region gives inferior limits of the SOI thickness and the process temperature, Thermal reaction between Ta and SiO2 films sets a superior limit of the process temperature, and a short-channel effect sets a superior limit of the SOI thickness.