Impact of the SiO2 interface layer on the crystallographic texture of ferroelectric hafnium oxide

Applying transmission Kikuchi diffraction (TKD) allows us to fundamentally investigate the Si-doped-hafnium-oxide (HSO) microstructure that results from the interface layer present in ferroelectric field-effect transistors. In addition to the predominant orthorhombic phase, dendritic HSO grains larger than 100nm govern the microstructure composition. Furthermore, the observed strong out-of-plane texture aligned along the [110] and [011] axis clearly differs from features found in hafnium oxide thin films grown on TiN layers. Our TKD analysis shows that the texture intensity strongly varies for samples annealed at different temperatures. Additionally, intra-granular misorientation and chemical composition analyses of the layers provide insight into the crystallization process of these ferroelectric thin films.

Automated summary

The TKD technique can be used to investigate the microstructure of Si-doped hafnium oxide in ferroelectric field-effect transistors, revealing dendritic grains and varying texture intensity with annealing temperatures.