Methods of fabricating a nonvolatile memory device using a resistance material and a nonvolatile memory device are provided. According to example embodiments, a method of fabricating a nonvolatile memory device may include forming at least one semiconductor pattern on a substrate, forming a metal layer on the at least one semiconductor pattern, forming a mixed-phase metal silicide layer, in which at least two phases coexist, by performing at least one heat treatment on the substrate so that the at least one semiconductor pattern may react with the metal layer, and exposing the substrate to an etching gas.