A method of manufacturing a cross-point memory array device is disclosed. In the method, a substrate is provided. A plurality of first conductive line patterns are formed over the substrate. An insulating layer is formed over the first conductive line patterns. The insulating layer includes an insulative oxide. A plurality of switching film patterns are formed on the first conductive line patterns by selectively doping a plurality regions of the insulating layer. A plurality of memory structures are formed on the plurality of switching film patterns, respectively. A plurality of second conductive line patterns are formed on the plurality of memory structures.