OS2406 A statistical study for distribution of local adhesion strength in semiconductor device metallization systems

Abstract

A technique to evaluate local interface strength measured a considerable range of scatter in toughness of interface between Cu and SiN cap layer in LSI interconnect. In order to estimate the range of uncertainty in the evaluation procedure, the same technique was applied to the interface of vapor-deposited Au and native SiO_2 on a silicon wafer, which was expected to have a relatively homogeneous adhesion strength. By combining the obtained results with the statistical analysis, uncertainties in the evaluation procedure were evaluated and excluded from the scatter in the measurement results of Cu/SiN interface. Finally, the intrinsic fluctuation of interface strength due to the material properties was successfully determined.