摘要 |
In a method for forming a high aspect ratio structure using copper in an ultra high-speed device, the degree of copper burying is heightened. A high aspect ratio structure, such as a fine connecting hole, is formed in a layer insulating film on a silicon substrate. Then, after a CVD-TiN film is formed to have a thickness of 10 nm on the insulating film, a copper film having a thickness of 1 mum is formed. In this case, the highly pure copper film is formed by controlling film-forming conditions so as to set oxygen and sulfur concentrations in the film equal to a fixed level or lower. Thus, during its burying in the connecting hole, the surface diffusibility and fluidity of the copper film heated by means of laser irradiation are facilitated.
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