Process for fabricating semiconductor device

Abstract

A process is disclosed for fabricating semiconductor devices, and especially for fabricating semiconductor devices having multiple levels of metallization separated by polyimide or other organic materials. The process avoids the sputter etching and redeposition of the lower metal layer during reactive ion etching of openings through the organic layer. Sequential layers overlying the first layer of metallization include a layer of oxide, a layer of organic material, and a second layer of oxide. The second layer of oxide functions as a hard mask for patterning the organic material. The first layer of oxide acts as an etch stop and protective layer to prevent attack of the underlying metal during reactive ion etching of the organic layer. The first layer of oxide is of limited areal extent to avoid subsequent problems with the organic layer. The oxide located at the bottom of the opening through the organic material as well as the second layer of oxide and any oxide which is sputtered and redeposited on the walls of the opening through the organic material are easily removed in a single etch step without adversely affecting the underlying metallization. After removing the oxide, a second layer of metallization is applied and patterned as required.