| 摘要 |
PURPOSE:To make it possible to improve a wiring density by forming an insular projection on the lower portion of the first layer metallic wirings, and forming a through hole, thereby reducing a stepwise difference and preventing a disconnection. CONSTITUTION:A silicone dioxide film 2 is formed on the main surface of a p type silicon substrate 1, a polycrystalline silicon film 7 is accumulated, and an insular pattern is formed by a photoetching method. The first layer aluminum wirings 3 are formed, and an interlayer insulating film 4 made of a silicon nitride film is accumulated. An organic film 8 such as a photoresist is coated, the surface layer is cut, the film 4 is isotropically etched, the film 8 is removed, and the second layer aluminum film 6 is deposited. The aluminum wirings of two layers are connected in a self-aligned manner on the top of the projection 7, the stepwise difference of the hole of the film 4 is small, and the step coverage of the aluminum becomes preferable. |
