Atomic layer deposition of ZrO₂ thin film on Si(100) using {η⁵:η¹-Cp(CH₂)₃NMe}Zr(NMe₂)₂/O₃ as precursors

Atomic layer deposition (ALD) of ZrO₂ thin films was investigated using a linked cyclopentadienyl-amido compound of zirconium, {η⁵:η¹-Cp(CH₂)₃NMe}Zr(NMe₂)₂ with ozone. The ALD-window was established as 300–380 °C with a growth rate of about 0.95 Å/cycle. A good film conformality of 0.95 for 5.7–6.1 nm-thick film was obtained for bottom and sidewall step coverages of 0.93 and 0.95, respectively. The ALD at 330 °C yielded a ZrO₂ having good crystallinity. The film showed low impurity levels and a strong tendency to form the tetragonal/cubic phases despite a low film thickness of 8.58 nm (root-mean-square roughness = 0.49 nm). Better ALD performance was obtained with this linked precursor than with the commonly used CpZr(NMe₂)₃ precursor. Furthermore, theoretical calculations for the ALD processes on hydroxylated Si wafer surfaces were performed by using density function theory. Initial growth mechanism of ZrO₂ from CpZr(NMe₂)₃ and {η⁵:η¹-Cp(CH₂)₃NMe}Zr(NMe₂)₂ were proposed on atomic-scale structure. - Highlights: • Linked and non-linked cyclopentadienyl-related Zr(IV) precursors were synthesized. • ZrO₂ thin films were fabricated on Si wafer via atomic layer deposition (ALD). • The linked precursor resulted in excellent thin film, compared with the non-linked one. • Quantum mechanical calculations were performed for initial ALD growth mechanism