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

Abstract

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–SiO2 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–SiO2 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.