Crystalline SrZrO3 deposition on Ge (001) by atomic layer deposition for high-k dielectric applications

Heteroepitaxial growth of crystalline SrZrO3 (SZO) on Ge (001) by atomic layer deposition is reported. Ge (001) surfaces are pretreated with 0.5-monolayers (ML) of Ba and an amorphous similar to 3-nm SZO layer is grown from strontium bis(triisopropylcyclopentadienyl), tetrakis (dimethylamido) zirconium, and water at 225 degrees C. This similar to 3-nm layer crystallizes at 590 degrees C and subsequent SZO growth at 225 degrees C leads to crystalline films that do not require further annealing. The film properties are investigated using X-ray photoelectron spectroscopy, x-ray diffraction, aberration-corrected electron microscopy, and capacitance-voltage measurements of metal-oxide semiconductor capacitor structures. Capacitance-voltage measurements of the SrZrO3/Ge heterojunctions reveal a dielectric constant of 30 for SrZrO3 and a leakage current density of 2.1 x 10(-8)A/cm(2) at 1 MV/cm with an equivalent oxide thickness of 0.8 nm. Oxygen plasma pretreatment of Ge (001), Zintl layer formation with 0.5 ML Ba, and atomic deuterium post-growth treatment were explored to lower interface trap density (D-it) and achieved a D-it of 8.56 x 10(11)cm(-2)eV(-1). Published by AIP Publishing.