| abstract |
(57) [Abstract] [Purpose] In a semiconductor integrated circuit device having a tungsten plug in a wiring structure, it is possible to prevent a short circuit and a disconnection of the wiring due to the collapse of selectivity of the tungsten plug technology, Improve product yield. [Structure] After a silicon oxide film 10 and an aluminum oxide film 12 are formed on a semiconductor substrate 1, these are sequentially etched using a resist mask to form a contact hole 14. Next, a tungsten film 15 is embedded in the contact hole 14 by a monosilane reduction CVD method or a hydrogen reduction CVD method of tungsten hexafluoride gas. At this time, the tungsten nucleus 16 also grows on the surface of the aluminum oxide film 12. Next, the aluminum oxide film 12 is removed with a hot phosphoric acid solution to lift off the tungsten nucleus 16 to form a tungsten plug in the contact hole 14. |