Linear Transfer Length Model (LTLM)

$$R_{Total}=\frac{R_s}{W}L+2R_C$$

• ${\rho }_c=\text{specific contact resistivity}$ $[{\rho }_c]=\Omega \cdot c{m}^2$

• $L_T=\sqrt{\frac{{\rho }_c}{{\rho }_{sheet}}}$ $L_T$ is the transfer length — the distance over which most of the current transfers from the semiconductor into the contact. It’s derived from the ratio of contact resistivity to sheet resistance.

• ${\rho }_c=L_T^2\cdot {\rho }_{sheet}$ This is just the rearrangement of the above — once you extract $L_T$ from the x-intercept of the LTLM plot (resistance vs. contact spacing) and know ${\rho }_{sheet}$ from the slope, you get ${\rho }_c$.