  In this work, an evaluation of the contact quality of black phosphorus (BP)
field-effect transistors (FETs) from different technologies previously reported
is performed by means of an efficient and reliable contact resistance
extraction methodology based on individual device practical characteristics. A
good agreement is achieved between the extracted values with the Y-function
method used here and reference values obtained with other methods considering
internal values as well as with more expensive methods involving fabricated
test structures. The method enables a direct evaluation of different steps in
the same technology and it embraces the temperature dependence of the contact
characteristics. Channel phenomena have no impact on the extracted contact
resistance values. High-frequency performance projections are obtained for
fabricated devices based on the extracted contact resistance.
