A MIM Diode with Ultra Abrupt Switching Process and High On/Off Current Ratio

Abstract

In this work, a TaOx-based Metal-Insulator-Metal (MIM) diode is demonstrated. This Cu/TaOx/W diode is fabricated with sputtering method without any high temperature process (~ 400oC), which shows promising compatabiltiy with CMOS back-end process. The fabricated diode exhibits abrupt switching process (~3mV/dec) with small switching voltage (~ 0.7V), high on/off current ratio more than 106, low leakage current (~ pA). Current is limited when the diode is switched to the on-state to avoid the hard breakdown caused by the thermal run-away. On/off current ratio can be further improved to 108 by the limited current increase at the precondition of ensuring the safty of the diode. This MIM diode can be easily integrated into high density PCM or RRAM cross-point arrays due to its simple fabrication process. Its nearly ideal diode behavior with ultra low on-resistance can also be used as an ESD protection device or as a rectifying element in circuit.