Methods of forming nonvolatile memory devices

Abstract

In a nonvolatile memory device and a method of fabricating the same, a device isolation layer is formed defining an active region in a semiconductor substrate. A gate insulation layer and a first conductive layer are formed on the semiconductor substrate. A pair of stack patterns are formed, each having a intergate dielectric layer pattern and a second conductive layer pattern on the first conductive layer. A mask pattern is formed on the first conductive layer pattern between the stack patterns, the mask pattern being spaced apart from each of the stack patterns. The first conductive layer is patterned using the stack patterns and the mask patterns as an etching mask. Impurity ions are implanted into the active region to form a pair of nonvolatile memory transistors and a select transistor. The resulting nonvolatile memory device includes a memory cell unit that includes the pair of nonvolatile memory transistors and the select transistor.