Impact of Zr Precursor on Electrical Characteristics of HfZrO Laminated Structure

In this study, the effects of Zr precursor [i.e., tetrakis(ethylmethylamino) Zr (TEMA-Zr) and cyclopentadi- enyl tris(dimethylamino) Zr (Cp-Zr)] on the laminated HfZrO (HZO) are investigated for the enhanced ferroelectric characteristics. The laminated HZO film with the Cp-Zr shows superior ferroelectricity (i.e., remnant polarization, spontaneous polarization, and coercive field) and dielectric constant owing to the higher proportion of the tetragonal phase (t-phase) and orthorhombic phase (o-phase). Therefore, the TEMA-Hf/Cp-Zr sample shows up to ~1.6 times larger memory window (MW) at the same film thickness (i.e., the film thickness can be reduced by ~37% with same MW) than the TEMA-Hf/TEMA-Zr sample. Moreover, the TEMA-Hf/Cp-Zr sample features the lower leakage current and the larger breakdown voltage. Accordingly, it is expected that the FeFET with the TEMA-Hf/Cp-Zr laminated structure can be applied to multibit operation with enhanced electrical characteristics.