| 摘要 |
PURPOSE: A method for forming a tungsten plug is provided with preventing a reaction between a titanium barrier and a silicon substrate and thereby reducing contact resistance. CONSTITUTION: In the method, a contact hole is formed in an insulating layer(203) on the silicon substrate(201), and then a cobalt layer is formed with a uniform thickness on a resultant structure. Next, the cobalt layer reacts with oxygen at high temperature, preferably at 470°C, and thereby forms a cobalt silicide layer(209). Next, the titanium barrier(211) is formed on the cobalt silicide layer(209), and then a titanium nitride barrier(213) is formed thereon. Thereafter, tungsten(215) is deposited enough to fill the contact hole so as to form the tungsten plug. The cobalt silicide layer(209) prevents a reaction between the titanium barrier(211) and the silicon substrate(201).
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