HfYOx gate dielectric has been deposited on strained-Si/Si0.8Ge0.2 by radio frequency cosputtering of HfO2/Y2O3 targets. Compositional, chemical, and electrical properties have been studied using X-ray photoelectron spectroscopy, X-ray diffraction, capacitance-voltage (C-V), and current-voltage measurements. O1s spectra shows a minimum defect due to M (Hf or Y)-OH and the bandgap was found similar to 4.9 +/- 0.05 eV. The measured Delta V-FB and hysteresis in high frequency C-V characteristics are used to study the pre-existing traps in the dielectric. Trapping kinetics as a function of stress time of (Au, Pt, Ni)/HfYOx/strained-Si/Si0.8Ge0.2 have been investigated under low field (similar to 1.6 MV/cm) from Delta V-FB and Delta G(peak). (c) 2010 The Electrochemical Society. [DOI: 10.1149/1.3516638] All rights reserved.