Understanding anomalous current-voltage characteristics in microchannel-nanochannel interconnect devices

► Investigated nonlinear current characteristics in a micro/nanochannel. ► Distinguished limiting resistance and overlimiting regions using a numerical model. ► Overlimiting current is attributed to the redistribution of induced space charges. ► Observed positive current rectification under combined AC/DC electric fields. ► The criteria for current rectification are proposed.