High Growth Rate of Erbium Oxide Thin Films in Atomic Layer Deposition from (CpMe)3Er and Water Precursors

Organometallic tris(methylcyclopentadienyl)erbium and water were successfully exploited as precursors for the atomic layer deposition (ALD) of Er2O3 thin films. Deposition studies were carried out in the temperature range 175–450 °C, where Si(100) and soda-lime glass were used as substrates. ALD-type growth mechanism could be verified at relatively low deposition temperatures of 250 °C and 300 °C, where a high growth rate (1.5 Å per cycle) for an ALD process was obtained. The deposited Er2O3 films were smooth and very uniform, and contained only low concentrations of carbon and hydrogen as impurities. The films were crystalline with the (111) orientation of the cubic phase dominating. The effective permittivity of the Er2O3/native SiO2 insulator stack was approximately 10.