| 摘要 |
PURPOSE:To remove a short circuit due to the insufficient strength of an upper side wiring by solftening sections except the connecting section of upper and lower wirings at a temperature of 500 deg.C or less, temporarily filling the sections except the connecting section with an insulating protective film, which can be removed by gas plasma, and removing the protective film after forming the upper side wiring in an air bridge method, through which wiring metals on the upper side and the lower side cross in three dimensions without through an insulating layer, in multilayer interconnection technique for an IC. CONSTITUTION:Lower layer metallic wirings 21 are formed through photolithography and a lift-off method, the whole surface is coated with an Si3N4 film 24, and connecting sections 25 of an upper layer and a lower layer are removed. A resist 23 is formed only to a crossing section and the peripheral region of the crossing section through the film 24, and baked at a temperature of 500 deg.C or less higher than a temperature where the resist softens, and the resist 23 is formed to a hemispherical shape by surface tension. An upper layer wiring 22 is applied while being fast stuck to the surface and crossing the resist 23, and end sections are connected to the lower layer wirings 21 through the connecting sections 25. The unnecessary resist 23 positioned under the wiring 22 is removed through plasma etching by O2 gas, and the upper layer wiring 22 in which a deformation, etc. are not generated, is acquired. |
