Method for forming multilevel interconnections in a semiconductor device

摘要

The present invention provides a novel method for forming multilevel interconnections in a semiconductor device. A silicon oxide film is formed on a semiconductor substrate. A first photo-resist film pattern is formed on the first silicon oxide film. The surface of the silicon oxide film covered with the photo-resist film pattern is exposed to a super-saturated hydrosilicofluoric acid solution to selectively deposit a first fluoro-containing silicon oxide film on the silicon oxide film by use of the first photo-resist film pattern as a mask. The first photo-resist film pattern is removed, thereby resulting in first grooves in the fluoro-containing silicon oxide film. First interconnections are formed within the first grooves. An inter-layer insulator is formed on an entire surface of the device and then subjected to a dry etching and a photolithography to form via holes in the inter-layer insulator. Conductive films are selectively formed in the via holes. A second photo-resist film pattern is selectively formed to cover the conductive films within the via holes. The entire surface of the device covered with the second photo-resist film pattern is exposed to a super-saturated hydrosilicofluoric acid solution to selectively deposit a second fluoro-containing silicon oxide film on the inter-layer insulator by use of the second photo-resist film pattern as a mask. The second photo-resist film pattern is removed, thereby resulting in second grooves in the second fluoro-containing silicon oxide film. Second interconnections are formed within the second grooves.