Measurement of low resistive ohmic contacts on semiconductors

Macroscopic analog models of planar contacts to semiconductor layers were made and equipotential lines underneath the contact were traced. Voltage drop and current density across the interfacial layer of such contacts were determined and compared to theoretically calculated values. The extended transmission line model (TLM) is used to describe the measurements and a reasonable limit for its application to the measurement of ρ
c
is
\rho_{c}/(\rho_{s} . h) > 0.2
; for
\rho_{c}/(\rho_{s} . h) \le 0.2
the model of Overmeyer appears to be applicable.