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

• 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.

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.