A Ladder Transmission Line Model for the Extraction of Ultralow Specific Contact Resistivity—Part II: Experimental Verification

In the first part of this two-part article, a ladder transmission line model (LTLM), featuring elimination of parasitic metal resistances and high accuracy for extracting specific contact resistivity p
_c
, is developed and verified by simulation. In Part II, the LTLM is applied experimentally to Ni contacts formed on the heavily Ga-doped Ge
_0.95
Sn
_0.05
film. Two types of Ni/p
⁺
-Ge
_0.95
Sn
_0.05
LTLM structures, single-cell and multicell LTLMs, are fabricated. Ultralow p
_c
values of 8.6±2×10
^-10
Ω-cm
²
and 1.1±0.3×10
^-9
Ω-cm
²
are extracted from the single-cell and multicell LTLMs, respectively. The good agreement of the extracted p
_c
from the single-cell and multicell structures validates the pc extraction by the LTLM. pc is also extracted by using refined transmission line model (RTLM). In contrast, the extracted pc by the RTLM is more than two times larger due to the ignored parasitic metal resistance. The proposed LTLM is a useful tool for an accurate assessment of p
_c
in advanced contact technology.