12 September

Epitaxial Ferroelectric Thin Films on Si(001): strain tuning of BaTiO3 and stabilization of polar phase in Hf0.5Zr0.5O2

Thursday 12 September 2019, 11:00am

Sala d'Actes Carles Miravitlles ICMAB, Campus UAB

ICMAB PhD Defense

PhD:  Jike Lyu from the Laboratory of Multifunctional Oxides and Complex Structures (MULFOX) at ICMAB.

Abstract: This thesis investigated the epitaxial lead free ferroelectric films on Silicon. It consists of two major parts: firstly, different from the conventional substrate-based strain engineering, we developed a new strain method to tune the lattice strain and ferroelectric polarization of BaTiO3 films epitaxially integrated with silicon based on balancing the thermodynamics and kinetics through controlling the growth parameters; secondly, we determined the growth window by PLD for epitaxially stabilizing the polar orthorhombic phase in Hf0.5Zr0.5O2 films on STO(001).

Further epitaxial growth of high quality Hf0.5Zr0.5O2 films has been successfully integrated on Si substrate in a capacitor heterostructure with different buffer layers presenting outstanding ferroelectric properties.

Supervisors: Florencio Sánchez, ICMAB-CSIC