The application of selective electroless plating for microelectronics applications

The feasibility of using electroless Nickel deposition for contact hole filling in Si VLSI technology has been demonstrated. The fundamentals of nickel plating are observed in the effects of such variables as temperature, nickel concentration and pH. Three types of electroless nickel solutions have been examined. In the first bath, the reducing agent was Nickel Hypophosphite, in the second, DMAB and in the third, Hydrazine. Pretreatment of the wafers involved immersing the wafers in an organic solvent. Surface topography and planarisation has been investigated by scanning electron microscopy (SEM) while the plating solution composition was investigated using nuclear magnetic resonance spectroscopy (NMR).