摘要 |
An insulating-film composition containing an insulating-film precursor and a pore-generating material is applied onto a surface of a semiconductor substrate, and a first heat treatment is performed to polymerize the insulating-film precursor without vaporizing the pore-generating material, to form a non-porous insulating film. Next, a resist pattern is formed on the non-porous insulating film, and dry etching is performed, using the resist pattern as a mask, to form a trench in the non-porous insulating film. After removing the resist pattern by ashing, the surface of the semiconductor substrate is cleaned. Next, a second heat treatment is performed to remove the pore-generating material from the non-porous insulating film and to form a porous insulating film. Thereafter, a copper layer is deposited in the trench on a barrier-metal film to form copper wiring.
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