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In this work, we present experimental results examining the energy distribution of the relatively high ͑Ͼ1 ϫ 10 11 cm −2 ͒ electrically active interface defects which are commonly observed in high-dielectric-constant ͑high-k͒ metal-insulator-silicon systems during high-k process development. This paper extends previous studies on the Si͑100͒/SiO x /HfO 2 system to include a comparative analysis of the density and energy distribution of interface defects for HfO 2 , lanthanum silicate ͑LaSiO x ͒, and Gd 2 O 3 thin films on ͑100͒ orientation silicon formed by a range of deposition techniques. The analysis of the interface defect density across the energy gap, for samples which experience no H 2 /N 2 annealing following the gate stack formation, reveals a peak density ͑ϳ2 ϫ 10 12 cm −2 eV −1 to ϳ1 ϫ 10 13 cm −2 eV −1 ͒ at 0.83-0.92 eV above the silicon valence bandedge for the HfO 2 , LaSiO x , and Gd 2 O 3 thin films on Si͑100͒. The characteristic peak in the interface state density ͑0.83-0.92 eV͒ is obtained for samples where no interface silicon oxide layer is observed from transmission electron microscopy. Analysis suggests silicon dangling bond ͑ P bo ͒ centers as the common origin for the dominant interface defects for the various Si͑100͒/SiO x /high-k/metal gate systems. The results of forming gas ͑H 2 /N 2 ͒ annealing over the temperature range 350-555°C are presented and indicate interface state density reduction, as expected for silicon dangling bond centers. The technological relevance of the results is discussed.

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We investigate the impact of rapid thermal anneals on structural and electrical properties of crystalline Gd 2 O 3 layers grown on Si with different orientations. Due to additional oxygen from the annealing ambient, a structureless two-layer stack (silicon-oxide-like and silicate-like) between the silicon and the crystalline oxide will be formed. The degradation of layers can be significantly reduced by sealing the layer with a-Si prior to annealing. For the capped layers, the effective capacitance equivalent thickness increases only slightly even after a 1000 • C anneal.