METHOD FOR MANUFACTURING A SEMICONDUCTOR MEMORY DEVICE

摘要

PURPOSE: A method for manufacturing a semiconductor memory device is provided to reduce variation of a critical dimension according to a pattern density and to decrease the number of process steps, by using TiON layer as a hard mask in forming a tungsten silicide interconnection. CONSTITUTION: A tungsten silicide layer(13) is formed on a structure in which a predetermined process is completed. A TiON layer(20) is formed on the tungsten silicide layer. A photoresist pattern as a mask for forming an interconnection is formed on the TiON layer. The TiON layer is etched with Cl2 base gas using the photoresist pattern as a mask. The tungsten silicide layer exposed by etching the TiON layer is etched with Cl2 and O2 based gas.