X-ray photoelectron spectroscopy measurement of the Schottky barrier at the SiC(N)/Cu interface

Electrical leakage in low-k dielectric/Cu interconnects is a continuing reliability concern for advanced <22 nm technologies. One leakage mechanism deserving increased attention is electron transport across the Cu/dielectric capping layer interface. The Schottky barrier formed at this interface is an important parameter for understanding charge transport across this interface. In this report, we have utilized x-ray photoelectron spectroscopy to investigate the Schottky barrier formed at the interface between polished Cu substrates and standard low-k a-SiC(N):H dielectric capping layers deposited by Plasma Enhanced Chemical Vapor Deposition. The authors find the Schottky Barrier at this interface to range from 1.45 to 2.15 eV depending on a-SiC(N):H composition and to be largely independent of various in situ plasma pretreatments.