Ultrathin (< 10 run) zirconium oxide (ZrO2) films have been deposited at low temperature (150 degrees C) on strained-Si on relaxed-Si0.8Ge0.2 substrates by microwave plasma enhanced chemical vapor deposition (PECVD). Interfacial and electrical properties of Al/ZrO2/strained-Si MOS capacitors have been characterized using capacitance-voltage (C-V) and conductance-voltage (G-V) techniques. It is observed that D-it ranges from 4.93 x 10(12) eV(-1) cm(-2) in (E-C - 0.35) eV to 1.86 x 10(12) eV(-1) cm(-2) in (E-C - 0.82) eV and decays slowly while the time constant (tau) ranges from 3.05 x 10(-6) s in (E-C - 0,38) eV to 1.24 x 10(-5) s in (E-C - 0.83) eV and rises slowly as the interface state energy is changed from the bottom of the conduction band (E-C) towards the mid-gap. Extracted value of electron capture cross-section, sigma(n) ranges from similar to 2 x 10(-12) to similar to 9 x 10(-13) cm(2) and doping concentration, N-d shows a value of similar to 4.97 x 10(16) cm(-3) (c) 2005 Elsevier B.V. All rights reserved.