Investigation of the filament properties in the HfO$_2$-based structures using conductive atomic force microscopy

The results of the research on the resistive switching in Pt/HfO$_2$/HfO$_x$N$_y$/TiN, Pt/HfO$_2$/TaO$_x$N$_y$/TiN and Pt/Al$_2$O$_3$/HfO$_2$/TaO$_x$N$_y$/TiN structures are presented. Active layers of the structures were deposited by atomic layer deposition. The formation of conductive filaments in all three structures was demonstrated using conductive atomic force microscopy. A full cycle of resistive switching with a microscope probe in these structures was also demonstrated. The properties of filaments formed at different voltages were studied, and the distributions of the filament density by conductivity and size were presented. The characteristics of the studied structures were compared. It appears that the Pt/Al$_2$O$_3$/HfO$_2$/TaO$_x$N$_y$/TiN structure has the greatest potential for resistive random-access memory application.