Lu2O3 thin film was deposited on n-type (100) Si substrates using pulsed laser deposition. A k value of 15.95 with an equivalent oxide thickness (EOT) of 1.10 nm and a current density of 2.6 x 10(-5) A/cm(2) at +1 V accumulation bias is achievable for the 4.5 nm thick Lu2O3 thin film deposited at room temperature after postdeposition annealing at 600 degrees C in oxygen ambient. Annealing a similar sample at 900 degrees C caused the EOT and leakage current density to increase to 1.68 nm and 1 x 10(-4) A/cm(2), respectively. High resolution transmission electron microscopy analysis has shown that Lu2O3 film remains amorphous at high temperature annealing at 900 degrees C. An x-ray reflectivity analysis on a separately prepared sample with lower annealing temperature (800 degrees C) suggested a formation of Lu-based silicate layer. It is believed that the formation of low-k silicate layer may have contributed to the observed increase in EOT and the reduction in the k value. (c) 2007 American Vacuum Society.