ELECTROLESS AND ELECTRO-PLATING OF CU ON SI

In this work, the deposition of copper onto silicon by either electro or electroless plating was investigated. Aqueous solutions with known concentrations of copper ions, with or without fluoric or sulfuric aci d, were used. Surface morphology, composition and thickness of the dep osited films were characterized by SEM, RES and profilometry. Depositi on under the cathodic regime yielded a film with a non-homogeneous gra nular structure independently, whether hydrofluoric acid had been adde d to the electrolyte or not. Under the anodic regime, deposition also occurred, but only if HF was added to the electrolyte. In this case, t he Cu deposits exhibited good adhesion, a metallic appearance and a ho mogeneous and compact granular structure with grain size of similar to 500 nm. In contrast to the electrodeposition, for the electroless dep osition, adhesion of the film was poor and grain sizes were similar to 100 nm. For both electroless and anodic electrodeposition cases, sili con dissolution was observed.