Patent ID: 6875684

Claim:
A method for forming a bit line of a semiconductor device, comprising the steps of: forming an impurity area by ion injection on a semiconductor substrate; depositing an insulation layer, and forming a contact hole by trench etching; removing a natural oxide layer and impurities in the contact hole by a cleaning process; forming a metallic barrier layer covering the contact hole by consecutively depositing a titanium layer and a titanium nitride layer on the insulation layer; depositing a tungsten layer directly on the metallic barrier layer and covering a portion of the metallic barrier layer that covers the contact hole; depositing a first nitride layer on the tungsten layer, and forming a bit line by depositing and patterning an anti-reflection layer; depositing a second nitride layer on the anti-reflection layer thereby preventing oxidation caused by an exposure of the tungsten; and depositing an oxide layer on the second nitride layer, and performing a thermal treatment whereby contact resistance of the bit line is stabilized.