A method for fabricating a forming-free resistive random-access memory (RRAM) device is provided. The method includes: fabricating an RRAM cell and annealing the RRAM cell. The RRAM cell includes: a bottom electrode, a switching oxide layer comprising at least one transition metal oxide; a top electrode, and an interface between the switching oxide layer and the top electrode. In some embodiments, the at least one transition metal oxide includes at least one of HfO