A barrier layer and a copper film are successively formed on a silicon
oxide film including a groove for wiring in the silicon oxide film and a
silicon nitride film, both formed on a semiconductor substrate.
Thereafter, the barrier layer and the copper film are removed from
outside of the groove for wiring, thereby forming a wiring. Tungsten is
selectively or preferentially grown on the wiring to selectively form a
tungsten film on the wiring. After the formation of the copper film, a
treatment with hydrogen may be performed. After the formation of the
wiring, the semiconductor substrate may be cleaned with a cleaning
solution capable of removing a foreign matter or a contaminant metal.
After the formation of the wiring, a treatment with hydrogen is carried
out.