Low Specific Contact Resistivity to n-Ge and Well-Behaved Ge ${\rm n}^{+}/{\rm p}$ Diode Achieved by Multiple Implantation and Multiple Annealing Technique

In this letter, the specific contact resistivity of metal on n-doped germanium is significantly reduced to
$3.8\times 10^{-7}~\Omega\cdot {\rm cm}^{2}$
by
${\rm P}^{+}$
multiple implantation and multiple annealing (MIMA) technique. The dramatic reduction of specific contact resistivity is attributed to the enhanced activation of n-type dopants, and a high electrical activation over
$1\times 10^{20}~{\rm cm}^{-3}$
is demonstrated by the spreading resistance profiling analysis. In addition, the fabricated germanium
${\rm n}^{+}/{\rm p}$
diode by
${\rm P}^{+}$
MIMA technique exhibits an
$I_{\rm ON}/I_{\rm OFF}$
ratio over
$10^{5}$
with low ideality factor of 1.11. The low specific contact resistivity of metal on n-doped germanium and well-behaved germanium
${\rm n}^{+}/{\rm p}$
diode are beneficial for the performance improvement of Ge nMOSFETs.