(44c) Kinetics and Mechanism of Moisture Interaction with Dielectric Oxides

The chemical interaction of moisture with porous dielectrics such as porous silicon oxide, hafnium oxide, and zirconium oxide is a critical issue in semiconductor manufacturing; it leads to various device yield and reliability problems. The interaction is a complex combination of chemical reaction plus transport in porous oxide and permeation in the matrix of some of the dielectrics. Hafnium and zirconium oxides are promising high-k materials to replace silicon oxide as the gate dielectric; polymeric low-k dielectrics are considered for replacement of silicon dioxide as an interconnect dielectric. Comparison of the relative susceptibility of these new materials to molecular contamination is important towards selection of an alternate dielectric. Moisture interactions with HfO2 , ZrO2 and low-k polymeric ultra thin films, deposited by Atomic Layer Chemical Vapor Deposition and spin coating, are investigated and compared to that of native SiO2. Results on the kinetics of moisture adsorption and desorption indicate that the HfO2 and ZrO2 react with moisture strongly compared to SiO2. Silicon dioxide and some of the low-k permeation takes place simultaneously with pore diffusion and reaction. New results on comparison of kinetics and mechanism of moisture interaction in these new dielectrics will be presented and compared.