Atomic Layer Deposition of Y2O3 Thin Films Using Y(MeCp)2(iPr-nPrAMD) Precursor and H2O, and Their Erosion Resistance in CF4-Based Plasma

Atomic layer deposition (ALD) of Y2O3 thin films was investigated using Y(MeCp)2(iPr-nPrAMD) precursor and H2O reactant. The self-limiting reaction mechanism of ALD-Y2O3 thin films was confirmed at a growth temperature of 260 °C. And, the saturated growth rate was confirmed to be ~0.11 nm/cycle. Also, it was demonstrated that a wide ALD temperature window from 150 °C to 290 °C maintains a consistent growth rate. ALD-Y2O3 thin films were found to have a typical cubic polycrystalline structure, independent of growth temperature, which can be attributed to their stoichiometric composition of Y2O3, negligible carbon impurity, and high film density, analogous to the Y2O3 bulk. Even at a low growth temperature of 150 °C, ALD-Y2O3 exhibited a markedly lower plasma etching rate (~0.77 nm/min) than that (~4.6 nm/min) of ALD-Al2O3 when using RIE at a plasma power of 400 W with a mixed gas of Ar/CF4/O2. Furthermore, the growth temperature of Y2O3 thin films had minimal impact on the etching rate.