Method for fabricating semiconductor devices including wiring forming with a porous low-k film and copper

A method for fabricating semiconductor devices comprising at least:

• a first step for forming a first insulating material layer on a sample;
• a second step for forming on said first insulating material layer a second insulating material layer including at least a porous low-k film with a dielectric constant less than 2.5;
• a third step for patterning said second insulating material layer by a plasma etching method;
• a fourth step for depositing a metal film on said second insulating material layer by a sputtering method;
• a fifth step for forming a copper layer on said metal film;
• and a sixth step for removing an unnecessary portion of said copper layer by Chemical Mechanical Polishing,
• wherein after said third step and before said fourth step, there is an etching process for removing predetermined part of said first insulating material layer by etching by means of plasma of a mixed gas containing at least NF3 through an opening patterned in said second insulating material layer in said third step,
• all the processes form said third to said fourth step are performed under dry process conditions in which said sample is not exposed to the atmosphere during all the periods from the start of said third step to the end of said fourth step, and
• a pure water treatment for cleaning said sample with pure water provided after said sixth step.