| 摘要 |
PURPOSE:To obtain LSIs of high reliability which produce no cracks in the cover film at the time of sealing, by a method wherein double layers consisting of metallic layer and an organic substance insulation layer are adhered at a time or more, and a required pattern is formed in this formed. CONSTITUTION:After adhesion of a CVD cover film, the wafer is coated with an Mo layer 19 of 2,000Angstrom thickness by sputtering. Thereafter, a precursor varnish of polyimide is applied by spin and baked for 1hr at 80 deg.C, and polyimide is developed by transcribing a required pattern; then, a polyimide film 20 of approx. 1-2mum thickness is obtained by baking for 1hr at 140, 200, 350 deg.C, respectively. The Mo layer 19 and the CVD cover film 18 are plasma-etched with the mask of the polyimide film 20, and a protection film is formed by dipping in a solution of acetic acid to stabilize the polyimide surface, rinsing, and drying. Further, the wafer is subjected to back polishing, back etching, annealing, and back Au evaporation. Such a manner can prevent the generation of cracks by decreasing the resistance against resin flows at the time sealing because the film surface more flattens by a thickness of 1mum or more. |
