Simulation of tunneling sensor MIM-nanostructures

Abstract

The vacuum deposition process of super thin films of rare earth elements (REE) oxides was investigated and simulation of MIM nanostructures on their base was carried out. Super thin films was deposited by reactive magnetron sputtering of metallic targets in the argon and oxygen mixture. At the optimum technological regime (discharge voltage 400-440 V, substrate temperature 573-598 K) the yttrium and holmium oxides films growth rate is correspondingly 3.5 and 2.8 nm/min, their specific resistance is more than 1013 Ohm/cm, the value of permittivity is 10.4-16.8. The sensor MIM nanostructures of Al-(REE)2O3-Al type on the basis of super thin films was obtained. The resistance simulation approach by linear approximation of current-voltage relation was considered. For the yttrium oxide film thickness of 5, 16 nm and MIM-contact area of 1•10-3, 2•10-3 mm2 increasing of the applied voltage from 0.04 to 1.2-1.5 V leads to increasing of current-voltage relation steepness from (1.5-2.5)•10-8 to (19-22)•10-8 A/V, and the resistance of the formed MIM nanostructures is firstly rising and then reducing in 1.9-4.0 times with the voltage increasing. MIM nanostructures was simulated as a negative differential conductivity elements. The current through MIM nanostructures has viewed as periodic impulses with frequency from ~100 GHz to ~10 THz.