Nand-type flash memory devices and fabrication methods thereof

Abstract

In an embodiment, a memory device includes a semiconductor substrate having cell active regions and a peripheral active region. Plugs, including bit line contact plugs, a common source line, a peripheral gate interconnection contact plug, and peripheral metal interconnection contact plugs are formed of the same conductive layer through the same process. Also, metal interconnections including bit lines, a cell metal interconnection, a peripheral gate interconnection, and peripheral metal interconnections directly connected to the plugs may be formed of the same metal layer through the same process. Accordingly, the interconnection structure such as the plugs and the metal interconnections is simplified and thus the process of their formation is simplified.