MANUFACTURE OF SEMICONDUCTOR DEVICE

PURPOSE:To realize a multilayer interconnection in which interconnections do not interfere electrically with each other and whose reliability is high by providing the following: a process by which a sidewall composed of a first insulating film is formed at a lower-layer interconnection; a process by which a sidewall composed of a first conductor film is formed at the first insulating film; and a process by which a second insulating film is etched selectively to form an opening part reaching the lower-layer interconnection. CONSTITUTION:A CVD silicon oxide film 2 is grown on a semiconductor substrate 1; openings are formed in required parts. Then, first aluminum interconnections 3 are formed. A plasma silicon oxide film 4 is left only on sidewalls of the first aluminum interconnections 3. Then, a CVD tungsten film 5 is left only on side-walls of the plasma silicon film 4. Then, opening parts 7 which reach the first aluminum interconnections 3 and the CVD tungsten film 5 are formed selectively. Then, second aluminum interconnections 8 which are connected to the first aluminum interconnections 3 and the CVD tungsten film 5 at the opening parts 7 are formed. The minimum size of the opening parts 7 is not limited by the width of the CVD tungsten film 5 and can be permitted up to the interval or lower of the first aluminum interconnections 3.