| 摘要 |
PURPOSE:To obtain multilayer interconnection of high reliability by setting the selection ratio of an etching velocity for an interlayer insulating film of upside of a wiring layer to an interlayer insulating film of downside to approx. 1.5 or more. CONSTITUTION:Aluminum wirings 14 are formed through an interlayer insulating film 13 of a quartz sputter to aluminum wirings 12 on an Si substrate 11, and aluminum wirings 15 are formed through an interlayer insulating film 15. The film 15 is formed of an Si3N4 film 15a, a superposed film 15b of a glass rotatably coating film and a PSG by a plasma CVD method. In this configuration, the selection ratio of etching velocity of the film 15 to the film 13 can be set to approx. 1.5-2, and when the quantity of O2 to be added to CF4 and pressure are selected, the ratio can be readily approached to 2. Thus, even if the connecting hole 18 of the film 15 is displaced, the film 13 is not overetched, the wirings 18 are not shortcircuited with the wirings 12, the reliability is improved, wiring pitch is reduced, and an IC can be highly integrated. |
