Abstract: A semiconductor device includes a barrier metal structure which are sandwiched between an electrode provided on a semiconductor chip and a bump. The barrier metal structure has a first through third conductive metal layers, where the third conductive metal layer as an uppermost layer thereof in contact with the bump covers the second conductive metal layer made of a material which is weak in resistance to diffusion and oxidation.

Abstract: Disclosed is a process for the preparation of a perfluorinated copolymer having a predetermined ratio of monomer units, which comprises copolymerizing 99.5 to 50 mole % of (I) tetrafluoroethylene with 0.5 to 50 mole % of (II) a monomer represented by the following general formula:CF.sub.2 =CFOCH.sub.2 C.sub.n F.sub.l X.sub.m H.sub.(2n+1-l-m) (II)wherein X stands for --Cl or --Br, n is an integer of at least 0, l is an integer of from 0 to (2n+1), m is 0 or 1, and the relation of l+m.ltoreq.2n+1 is established, in the state where both the monomers are dissolved at a predetermined monomer ratio in an organic solvent, to thereby form a copolymer comprising units of the monomers at a ratio substantially equal to said predetermined monomer ratio, and fluorinating said copolymer with molecular fluorine.The heat resistance is highly improved in the copolymer obtained according to this process without degradation of other physical properties, and generation of hydrogen fluoride by heat is hardly caused.