Quantum Interference of Electron Wave in Metal (CoSi₂)/Insulator (CaF₂) Resonant Tunneling Hot Electron Transistor Structure

We report the observation of multiple negative differential resistance (NDR) in nanometer-thick metal (CoSi 2 )/insulatro (CaF 2 ) resonant tunneling hot electron transistor (RHET) grown on a silicon substrate. In this transistor, electrons from a resonant tunneling emitter with a 2.2-nm-thick CoSi 2 quantum well are transferred to the conduction band of a 4.0-nm-thick CaF 2 collector barrier region. Multiple NDR observed here may be attributed to the modulation of the transmission probability of electron waves due to quantum interference in the conduction band of the insulator (CaF 2 ) collector barrier layer between two metal (CoSi 2 ) layers, which is a different mechanism from the resonance in quantum wells previously reported.