New and simple method of contact processing characterization using atomic force microscopy

This article reports on the use of atomic force microscopy coupled with a simple wet chemical sample preparation to characterize processes involved in the realization of 0.4 mu m metal on silicon contacts. Photolithography and contact etching processes both lead to high aspect ratio topography (>4). The samples are imaged after a preparation which removes the high aspect ratio and leads to a better image. The main parameters of this new procedure are highlighted in this report, namely contact area for lithography and etching processes and silicon consumption for the etching process. The contact silicidation process is also monitored, and the electrical results are correlated with the silicide thickness formed in the contact. (C) 1996 American Vacuum Society.