SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE AND MANUFACTURE THEREOF

摘要

PURPOSE: A semiconductor integrated circuit device and a manufacture thereof are provided to reduce contact resistance by preventing reduction of a contact area between a plug and a barrier layer in a DRAM in which a bit line is formed on the plug composed of a polycrystalline silicon film via the barrier layer. CONSTITUTION: When a plug(21) composed of a polycrystalline silicon film is formed inside a contact hole(19) to which a bit line(BL) is connected, the upper surface of the plug(21) is recessed to a level lower than the upper end portion of the contact hole(19). A plug(22) composed of a laminated layer film of a TiN film(26) and a W film(27) is formed on the plug(21). Subsequently, a bit line BL having a thinner width than the diameter of the contact hole(19) is formed by patterning the W film deposited on the contact hole(19). At this time, the W film(27) constituting the plug(22) is also etched in the contact hole(19), but the TiN film(26) constituting the other part of the plug(22) is hardly etched.