A Ladder Transmission Line Model for the Extraction of Ultralow Specific Contact Resistivity—Part I: Theoretical Design and Simulation Study

A ladder transmission line model (LTLM) that features capability to eliminate parasitic metal resistance from contact metal and access electrodes, a simple fabrication process, and a sub-10
^-10
Ω·cm
²
resolution is demonstrated for accurate extraction of the specific contact resistivity ρ
_c
. The proposed LTLM is verified by technology computer-aided design (TCAD) simulation and a twolayer distributed-resistor network model. After eliminating the parasitic metal resistance, the current spreading and crowding effects are the main factors that contribute to the extraction error in LTLM. The effects of current spreading and crowding on the extraction of ρ
_c
in LTLM are further quantitatively analyzed and design guidelines to achieve a sub-10
^-10
Ω·cm
²
resolution of ρ
_c
extraction are provided. The details of theoretical modeling and simulation of LTLM are documented in Part I. The experimental demonstration of extracting sub-10
^-9
Ω·cm
²
ρ
_c
using the proposed LTLM is provided in Part II.