The <inline-formula> <tex-math notation="LaTeX">${\sim } 3\,{\times } 10^{20}$ </tex-math></inline-formula> cm<inline-formula> <tex-math notation="LaTeX">$^{-3}$ </tex-math></inline-formula> Electron Concentration and Low Specific Contact Resistivity of Phosphorus-Doped Ge on Si by <italic>In-Situ</italic> Chemical Vapor Deposition Doping and Laser Annealing

Abstract

The phosphorus incorporation by chemical vapor deposition and activation by laser annealing reaches the electron concentration of $\sim 3\times 10^{20}$ cm $^{-3}$ . The pulsed laser not only activates the phosphorus but also produces the biaxial tensile strain of 0.35%. With the nickel germanide contact, the specific contact resistivity reaches as low as $1.5\times 10^{-8}~\Omega $ -cm2 by greatly reducing the tunneling distance. Due to 4% misfit between Ge and Si, there are still misfit dislocations near the Ge/Si interface. The misfit dislocations at the Ge/Si interface lead to the ideality factor of 1.6 for the Ge/Si hetero-junction diode with ON/OFF ratio of $\sim 1\times 10^{5}$ .