Influence of Doping on Ni Electroless Deposition at Single Crystalline Si

Abstract

In this research, we have prepared nickel thin films by electroless deposition on a Si substrate as a fundamental study for providing nanoscale ohmic contacts between metal interconnection and the Si substrate, as well as investigated nucleation and growth behavior with different doping types and doping levels. The electroless deposition of Ni was highly affected by the surface condition of Si, which could be changed by the type of doping and doping level. When the Si substrate was doped with As, the nucleation rate was significantly increased, by which the deposition rate was less sensitive to the concentration of NH4F. However, when P-type doping was performed, the deposition rate increased because of a high etch rate of Si with NH4F, which was caused by amorphization of the Si by P-type doping.