Switching layer optimization in Co-based CBRAM for >10 5 memory window in sub-100 µA regime

Abstract

Co/HfO2-based CBRAM stacks are optimized to enlarge the memory window for low-current (50 mu A) operation. First, we dope the switching layer with Si to decrease the pristine current, thus enlarging the memory window. Then, we reduce the forming voltage by scaling the Si-doped HfO2 thickness. Finally, we extend the endurance lifetime and reduce the write time by introducing a hygroscopic oxide, LaSiO, in combination with HfSiO, to enhance Co ion hopping through hydroxyl groups. We further outline the important role of the position of the hygroscopic layer with respect to the Co active electrode in enlarging the memory window of the CBRAM device up to > 10(5).