SELECTIVE SEEDING OF COPPER-FILMS ON POLYIMIDE-PATTERNED SILICON SUBSTRATE, USING ION-IMPLANTATION

Our recent work has established the successful use of ion implantation into silicon or polyimide to seed the electroless plating of copper o n these surfaces. The substrates exhibit a threshold implantation dose , below which the plating does not occur. The threshold implantation d ose for seeding of electroless Cu films on Pd-implanted Si is observed to be about 20 times lower than that for polyimide. In this paper we demonstrate a successful exploitation of this difference in threshold dose to deposit thin copper structures selectively only on (100) silic on wafer patterned with polyimide and implanted with Pd ions. The proc ess is used to fabricate copper coils with a track width of 10 mu m an d track spacing 10 mu m. A detailed analysis of the implanted and plat ed samples, using Rutherford backscattering spectroscopy (RBS), scanni ng electron microscopy (SEM) and optical microscopy is also presented.