SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD

PROBLEM TO BE SOLVED: To reduce a contact resistance between a tungsten plug and a second metal interconnection in via-holes formed in a multilayer interconnection of a semiconductor device. SOLUTION: A first metal interconnection 13 is formed on a semiconductor substrate, and then an interlayer insulation film 14ab which coats the first metal interconnection 13 is formed, and the second metal interconnection 18 is formed on the interlayer insulation film. In order to electrically connect the second metal interconnection 18 and the first metal interconnection 13, the plurality of via-holes 15 and 15 are formed in the interlayer insulating film. Inside the via-holes 15 and 15, for example, the tungsten plugs 17 and 17 are deposited. The via-holes 15 and 15 which are adjacent to each other are separated from each other by a via-hole isolation formation section 16b which is lower than the depth of the via-holes. The tungsten plugs 17 and 17 deposited in the adjacent via-holes 15 and 15 are connected to each other, while covering the via-hole isolation formation section. COPYRIGHT: (C)2005,JPO&NCIPI