Characteristic Impedance of Integrated Interconnections: RF Experimental Extraction and Limit of Validity

In this paper we extract the characteris tic impedance of Back-End Of Line (BEOL) interconnections from radio frequency (RF) scattering parameter measurements. Quantification of the electric interconnection performance on a broad fre quency band requires a good knowledge of the characteristic impedance Z c and the propagation exponent γ. This propagation exponent is easily obtained by measuring two interconnections with different le ngths. However, because of the complex test structu re with mismatched ports where interconnections are embedded, the extraction of Z c from scattering parameter measurements remains challenging. To solve this problem, we propose an approach based on the Winkel method without using simplified hypotheses generally applied. Limits of validity for our de - embedding procedure to extract characteristic impedance are also analyzed.