Atomic layer deposited $HfO2/HfSixOyNz$ stacked gate dielectrics for metal-oxide-semiconductor structures Available to Purchase

$HfSixOyNz$ layers were grown on Si substrates prior to $HfO2$ growth in order to investigate the growth of an interfacial layer between $HfO2$ and Si substrate and the chemical composition changes at the interfacial region. The effects of the $HfSixOyNz$ buffer layers were also investigated. The $HfSixOyNz$ and $HfO2$ films were grown by remote plasma atomic layer deposition using $N2/O2$ plasma and $O2$ plasma, respectively. The $HfSixOyNz$ films were grown using a TDEAH precursor and $N2/O2$ mixed plasma. The Hf-N and N-O bonds of the $HfSixOyNz$ layers were easily broken by annealing at $800°C$ in $N2$ ambient because their bonds were relatively weak. The peak intensities of the Si-O-N, Hf-O-Si, and Si-O bonds at the interfacial region increased after annealing. The excess N atoms due to the breaking of the Hf-N and N-O bonds can form bonds with Si atoms in the interfacial region and cause the growth of $SiOxNy$ or $SiNx$⁠. The excess Hf and O atoms can grow $HfSixOy$ or $SiO2$ due to interactions with Si atoms. The formation of the $HfSixOyNz$ layer can suppress the growth of Hf silicate or an interfacial layer. The formation of a thick $HfSixOyNz$ layer enhanced the thermal stability of the interfacial layer of the $HfO2$ film as it had a larger amount of effective fixed oxide charges than a thin $HfSixOyNz$ layer.