Dopant segregation and nickel stanogermanide contact formation on p +Ge 0.947Sn 0.053 source/drain

Abstract

P +Ge 1-xSn x is a promising source and drain (S/D) stressor material for Ge p-MOSFETs, and an S/D material in Ge 1-xSn x channel p-MOSFETs. In this paper, we investigate the dopant segregation (DS) effects in the stanogermanidation of p +Ge 0.947Sn 0.053 (boron-doped). A study comparing the contact resistance R C of nickel stanogermanide [Ni(Ge 1-xSn x) or Ni(GeSn)] contact on p +Ge 1-xSn x and nickel germanide (NiGe) contact on p + Ge was performed. A more pronounced DS effect is achieved during the stanogermanidation in comparison with the NiGe/p + Ge control. R C is 44% lower in the Ni(Ge 1-xSn x)/p + GeSn structure as compared to the NiGe/p + Ge control. The reduced R C is attributed to a more significant DS effect and the lower bandgap of Ge 1-xSn x as compared with Ge. © 2012 IEEE.