Novel ion bombardment technique for doping limited Cu source in SiO _x-based nonvolatile switching layer

A novel ion bombardment (IB) technique is presented to dope a limited Cu source in an SiO_x switching layer (SiOx Cu SL) for nonvolatile memory applications. Compared with other Cu-doping methods, this IB technique has many benefits, including a local-doping effect, room-temperature process, and compatibility with current IC manufacturing technology, besteading the 1T\hbox{-}1R integration. Through transmission electron microscopy and energy dispersive spectrometer analyses, an IB-induced SiO_x:Cu SL is confirmed. In contrast with the conventional z{\rm Cu}/{\rm SiO} _x-stacked sample, this IB-induced SiO_x:Cu SL exhibits superior performance in terms of lower forming/RESET voltages, higher uniformity of SET/RESET voltages, and more stable high-temperature retention characteristics. Additionally, so far, this IB-induced TaN SiO_x:Cu TaN device has shown the best switching endurance properties for the general SiO_x-based Cu filament resistance random access memory.