Comparison of standard macroscopic and conductive atomic force microscopy leakage measurements on gate removed high-k capacitors

Understanding the origin and mechanism of detrimental local phenomena such as charge trapping, trap assisted tunneling, and breakdown in high-k gate oxides adds to the improvement of refining the layer deposition process. Conductive atomic force microscopy (AFM) is a relatively new technique that is able to visualize these local phenomena. In this work we improve the quality of the comparison between standard macroscopic and conductive AFM (C-AFM) microscopic gate leakage measurements by enabling measurements on the exact same dielectric layers of metal gate high-k capacitors and transistors, using a well tuned gate wet etch process. An agreement in leakage current between both measurement types is obtained. Furthermore, we visualize with C-AFM the location and current magnitude of breakdown spots which were induced by standard macroscopic electrical stress. The ability of investigating the local leakage behavior of real devices as it is shown in this work opens the way to better understand gate leakage m...