In this study, what occurs at the SiO2/substrate interface and how Si atoms in SiO2 behave in interfacial SiO2 scavenging in a HfO2 gate stack have been investigated. Since the same scavenging occurs on both Si and SiC substrates, the SiC substrate is used to study the role of the substrate. The characterizations of the SiO2/SiC interface show no Si growth on the substrate and no consumption of the substrate in the SiO2 scavenging. Isotope tracing experiments for a HfO2/SiO2/Si stack further demonstrate that atomic Si is generated in scavenging and diffuses out through the HfO2 layer. On the basis of these findings, the reaction at the SiO2/substrate interface is thermodynamically discussed.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)