Crystal and electrical characterizations of epitaxial CeXZr1-XO2 buffer layer for the metal/ferroelectric/insulator/semiconductor field effect transistor

We evaluated the crystallinities of CeXZr1-XO2 (X=0.10-0.20) thin films used as intermediate layer for metal/ferroelectric/insulator/semiconductor field effect transistors (MFIS-FETs), using reflection high-energy electron diffraction (RHEED), X-ray diffraction (XRD) and X-ray pole figure measurement. The crystal alignments of CeXZr1-XO2 films On Si(100) were CeXZr1-XO2 [100]//Si[100] or CeXZr1-XO2[100]//Si[001], in the plane. The breakdown field of CeXZr1-XO2 was about 3 MV/cm (at I=nA/cm(2)). From C-V measurements, it was found that the electrical properties of the intermediate lavers of the MFIS-FETs were good. Oriented perovskite PbTiO3 films were deposited on CeXZr1-XO2/Si(100) substrates by digital chemical vapor deposition (CVD). These PbTiO3 films included many PbTiO3 grains aligned with the [100] or [001] axis parallel to the [101] axis of the CeXZr1-XO2 crystals at the plane in the PbTiO3/CeXZr1-XO2 interface, From C-V measurements of an Al/PbTiO3/CeXZr1-XO2/Si(100) sample, we obtained a threshold hysteresis (memory window) of about 1.4V.