Characteristics of remote plasma atomic layer-deposited $HfO2$ films on $O2$ and $N2$ plasma-pretreated Si substrates

Characteristics of remote plasma atomic layer-deposited $HfO2$ on Si, which has a very thin $SiO2$ interlayer with and without remote plasma nitridation, have been investigated. The thin $(∼1.5nm)$ intermediate layer containing nitrogen, which was prepared by sequential $O2$ and $N2$ remote plasma treatment of the Si substrate, can effectively suppress growth of the unintentional interface layer. In addition, it enhances the thermal stability and the resistance to oxygen diffusion during rapid thermal annealing. The $HfO2$ film containing the remote plasma nitrided $SiO2$ interlayer annealed at $800°C$ showed a lower equivalent oxide thickness of $∼1.89nm$ and a lower leakage current density (⁠$3.78×10−7Acm−2$ at $∣VG−VFB∣=2V$⁠) compared to a non-nitrided sample of the same physical thickness. Also, we compared the characteristics of $HfO2$ films annealed in two different ambient environments, $N2$ and $O2$⁠.