| 摘要 |
PURPOSE: A method for forming a bit line is provided to obtain fine pattern and to reduce loss of a hard mask by using a Ta film as an anti-reflective coating layer. CONSTITUTION: A Ti/TiN layer as a glue layer, a tungsten film, a silicon nitride layer as a hard mask, and a Ta film as an anti-reflective coating layer are sequentially formed on a substrate(10). An anti-reflective coating film made of Ta is formed by first dry-etching the Ta film using Cl-based gas. A hard mask film(13a) of silicon nitride is formed by second dry-etching the silicon nitride layer using Cl-based gas. A tungsten film(12a) is formed by third dry-etching the tungsten film using F-based gas. A glue film(11a) is formed by fourth dry-etching the Ti/TiN layer using Cl-based gas, thereby forming a bit line.
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