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Improved adhesion of electroless metal deposited on an organic dielectric layer with phase separated morphology is accomplished by the spontaneous formation of a morphologically and topographically rough surface. In one embodiment a ternary solution of a polar solvent and two polymer precursors of the same polymer which are separable in two phases of different order are cast in film on a substrate and heated to form two phases of different order to spontaneously produce a rough surface. Upon exposure to an alkaline solution, one phase is etched at a faster rate than the other. Seeding and electroless deposition of a metal on the rough surface results in improved adhesion of the metal to the dielectric layer. In a second embodiment a quaternary solution of a polar solvent, a seeding agent, two polymer precursors of the same polymer which are separable in two phases of different order are cast in a thin film on a substrate and heated to form three phases. Upon curing the precursors there is surface roughening as a result of phase separation. Upon exposure to alkaline solution there is etching of one of the polymer phases at a faster rate and simultaneous opening of the seeding colloid. The rough surface is overcoated with a photoresist, exposed and developed. Subsequent electroless metal deposition results in improved metal to dielectric layer adhesion. The method is applicable to selective deposition of electroless copper onto a polyimide layer.