| 摘要 |
PURPOSE:To contrive to improve the reliability by elimination of the possibilities of the increase in through hole resistance and the disconnection at the stepwise difference of the through hole by a method wherein the stepwise difference is etched in tapered form. CONSTITUTION:After a surface protection film 2 and a wiring 3 of the first layer are laminated on a semiconductor substrate 1 finished in the process of forming a discrete semiconductor element, an intermediate insulation film 4 is deposited and patterned, and then a resist pattern 5 is obtained. Next, it is spin- coated with a silica film 7, and then through hole etching is performed by the dry etching system. A tapered silica film 7' remains in the periphery of the through hole, the silica film at the center thereof being removed by etching, and the insulation film 4 being accordingly exposed to the etching atmosphere. At the point that through hole etching is finished, the insulation film 4 around the through hole 4 becomes retarded in etching, with the result that the tapered stepwise difference of the through hole can be obtained. Thereafter, the resist pattern 5 is removed, and a wiring 6 of the second layer is attached, thus obtaining a double-layer wiring structure. |
