Thin SiO2 oxides implanted by very-low-energy (1 keV) Si ions and subsequently annealed are explored with regards to their potential as active elements of memory devices. Charge storage effects as a function of Si fluence are investigated through capacitance and channel current measurements. Capacitance–voltage and source–drain current versus gate voltage characteristics of devices implanted with a dose of 1×1016 cm-2 or lower exhibit clear hysteresis characteristics at low electric field. The observed fluence dependence of the device electrical properties is interpreted in terms of the implanted oxide structure. © 2000 American Institute of Physics.