Distinct nucleation and growth kinetics of BaTiO3 on Ge (001) by RF magnetron sputtering

Abstract

The integration of metal oxide films with conventional semiconductors like silicon (Si) and germanium (Ge) enables the introduction of functionalities in semiconductor devices. This work experimentally demonstrates the BaTiO3 (BTO) thin film with crystalline Amm2 structure grown directly on Ge(001) using RF magnetron sputtering. In addition, its nucleation and growth kinetics are analyzed in detail. A systematic investigation of the crystal structural, optical, and morphological properties of BTO grown under different chamber pressures is performed. This study presents a growth model related to 3D + 2D growth to improve the mobility of barium (Ba) and titanium (Ti) atoms, with a stoichiometric ratio of Ba:Ti approaching 1.1. Consequently, at a wavelength of 800 nm, the refractive index (n) of BTO was approximately 2.15, rivaling those grown by pulsed laser deposition in refractive index.