Effects of swift heavy ion irradiation on the performance of HfO2-based resistive random access memory devices

In this work, the effects of 120 MeV Ag ion irradiation on the switching properties of Au/HfO2/Au-based Resistive Random Access Memory (RRAM) devices are reported. The ion fluence is varied between 5 × 1010 and 5 × 1012 ions/cm2 while two device sizes, with active areas 10 µm × 10 µm and 20 µm × 20 µm, are tested. In each case, 16 devices are subjected to ion irradiation and it is shown that the set voltages are generally lower and the spread in the switching voltages is reduced for the irradiated samples in comparison to the pristine devices. The existence of a critical dose of 5 × 1011 ions/cm2 up to which an improvement in the device performance is observed. Photoluminescence studies indicate the presence of oxygen-related vacancies in both pristine and irradiated samples, which may be the reason for the observed forming free switching behavior. Swift heavy ion irradiation is, thus, a simple but effective technique to tune the performance of HfO2-based resistive switching devices. The study also indicates the significance of radiation damage and reliability of these devices beyond a critical fluence.