Dual damascene interconnection in semiconductor device and method for forming the same
View Patent ↗A dual damascene interconnection in a semiconductor device is formed to be capable of preventing fluorine (F) component from being diffused through sidewalls of a via hole and a trench. The dual damascene interconnection includes a lower metal interconnection film, an intermetal insulating film having a via hole and a trench and formed on the lower metal interconnection film, first and second insulative spacer films formed on sidewalls of the via hole and the trench, respectively, a barrier metal layer covering the first and second insulative spacer films and the lower metal interconnection film in the via hole and the trench, and an upper metal interconnection film formed on the barrier metal layer, the via hole and the trench being filled with the upper metal interconnection film.
1. A method for forming a dual damascene interconnection in a semiconductor device, comprising the steps of:
forming an etch stop film and an intermetal insulating film sequentially on a lower metal interconnection film, said intermetal insulating film being formed with a FSG film;
forming a via hole so as to expose the etch stop film on the intermetal insulating film by performing an etching process using a mask pattern for via hole formation;
forming a trench by performing an etching process using a mask pattern for trench formation;
forming an insulating film on an exposed surface of the etch stop film and a surface of the intermetal insulating film;
forming first and second insulative spacer films with a USG material on sidewalls of the via hole and the trench, respectively, by performing an etching process for the insulating film, and exposing a portion of the etch stop film;
exposing the lower metal interconnection film by removing the exposed portion of the etch stop film;
forming a barrier metal layer on the first and second insulative spacer films; and
forming an upper metal interconnection film on the barrier metal layer, the via hole and the trench being filled with the upper metal interconnection film.
2. The method of claim 1 , wherein, the step of forming the first and second insulative spacer films with a USG material includes forming a USG film at a maximal thickness of 300 .ANG.
3. The method of claim 1 wherein, the step of forming a barrier metal layer includes forming a Ta/TaN film.
4. The method of claim 1 , wherein the step of performing an etching process for the insulating film includes using a plasma dry etching process.