Integration of Plasma-Assisted and Rapid Thermal Processing for Low-Thermal Budget Preparation of Ultra-Thin Dielectrics for Stacked-Gate Device Structures

This paper discusses a new approach to the formation of ultra-thin gate dielectrics for Si-ULSI applications in which separately controlled plasma-assisted and/or rapid thermal processing steps are combined to fix the chemical bonding and minimize the defect structure at the Si–SiO 2 interface, and within the dielectric layers. One example of this approach combines (i) low-temperature (300° C) plasma-assisted processing to control the initial bonding chemistries at (a) the Si–SiO 2 interface, and (b) in homogeneous oxide, or composite dielectrics with nitride or oxynitride layers, with (ii) higher temperature (900° C), but low-thermal budget, rapid thermal annealing to promote physical and/or chemical relaxations that minimize both interfacial and bulk dielectric defects, thereby improving device performance.