| 摘要 |
PURPOSE:To support and reinforce an insufficient strength of an upper layer wiring and avoid a short circuit between wirings by a method wherein the upper layer wiring is protected by a nitride film except a connection part between the upper and the lower wirings and an air bridge is formed at that state. CONSTITUTION:A lower layer metal wiring 1 is formed on an integrated circuit 10 and a resist 2 is left on a crossing part and its surrounding domain. Then a silicon nitride film 3 is formed as a protecting film. After that, a resist pattern is formed on the surface except three domains, i.e. a connection part 5 between the upper and the lower layer wirings, pad parts of the integrated circuit and a part surrounding an air-bridge except the part of the upper layer wiring 4. The silicon film 3 is etched using the resist as a mask. The upper layer wiring 4 is formed by the same method as the lower layer wiring. Because the cross section of the silicon film 3 is softened and almost round, a discontinuity at a stepped part of the silicon film 3, i.e. a step cut, is eliminated.
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