Method of forming a tungsten plug of a semiconductor device.

摘要

A tungsten plug 17 for a semiconductor device is formed by first depositing a barrier layer 16 on an insulating layer 14 provided with a contact hole, and then depositing a tungsten layer over the entire surface. The tungsten layer is then etched to form the plug 17 and any tungsten residues 19A remaining outside the contact hole are then oxidised before being removed by etching. The barrier layer 16 comprises a titanium and a titanium nitride layer. The plug forms a connection between a lower wiring layer 13 and an upper wiring layer (not shown).