Nanolaminates comprising of TiO₂ or HfO₂ sublayers within an Al₂O₃ matrix are grown with atomic layer deposition. These nanolaminates provide an improved silicon surface passivation compared to conventional Al₂O₃ films. The physical properties of the nanolaminates can be described with a dynamic growth model that considers initial and steady-state growth rates for the involved metal oxides. This model links the cycle ratios of the different atomic layer deposition precursors to the thickness and the material concentrations of the nanolaminate, which are determined by means of spectroscopic ellipsometry. Effective carrier lifetime measurements show that Al₂O ₃-TiO₂ nanolaminates achieve values of up to 6.0 ms at a TiO₂ concentration of 0.2%. In Al₂O₃-HfO ₂ nanolaminates, a maximum effective carrier lifetime of 5.5 ms is reached at 7% HfO₂. Electrical measurements show that the TiO ₂ incorporation causes strong hysteresis effects, which are linked to the trapping of negative charges and result in an enhanced field effect passivation. For the Al₂O₃-HfO₂ nanolaminates, the capacitance data clearly show a very low density of interface traps (below 5·10¹⁰eV^-1·cm^-2) and a reduction of the fixed charge density with increasing HfO₂ concentration. Due to the low number of recombination centers near the surface, the reduced field effect passivation only had a minor impact on the effective carrier lifetime.