METHOD FOR FABRICATING TUNGSTEN BITLINE

摘要

PURPOSE: A method for fabricating a tungsten bitline is provided to decrease a dopant loss and improve contact resistance by forming an undoped electrostatic discharge(ESD) layer after a source/drain region is formed and by performing a bitline process. CONSTITUTION: A gate oxide layer(20) is formed on a semiconductor substrate(10). A gate electrode in which a polysilicon layer, a tungsten nitride layer and a tungsten layer are stacked is formed on the gate oxide layer. A mask insulation layer pattern is stacked on the gate electrode. An insulation layer spacer is formed on the sidewall of the gate electrode. The source/drain region(80) is formed in the semiconductor substrate at both sides of the gate electrode. The undoped ESD layer is formed on the source/drain region. An interlayer dielectric(100) is formed on the semiconductor substrate. The interlayer dielectric on the ESD layer is etched to form a bitline contact. A predetermined thickness of the first and second barrier metal layers is formed on the semiconductor substrate. A rapid thermal process(RTP) is performed. A predetermined thickness of the third barrier metal layer(140) is formed on the semiconductor substrate. A tungsten layer(150) is formed.