Construction and Operation of Three-Dimensional Memory and Logic Molecular Devices and Circuits.

摘要

We set out to show proof-of-concept of fabricating molecular transistors which could be used as the basis for future molecular circuits. During the research, we demonstrated two new types of metal-oxide semiconductor transistors: vertical metal-insulator tunneling transistors (MITTs) and an additional device in which a self-assembled fullerene monolayer is coupled to a MITT. The presence of the molecular layer allows the transistor to exhibit higher currents and less leakage. We also constructed a ferrocene-based self- assembling monolayer attached to gold nanoparticles, exhibiting a gate effect which allows control of the transistor rectification via the gate voltage. The theoretical model to support this, and the fabrication and control techniques used to produce the device, may provide new insights on gated molecular junctions. Finally, we explored three-dimensional logic and memory devices in the form of resonant tunnel diodes (RTDs) used in the pre- CMOS era to construct digital circuits but with prohibitive fabrication costs. We demonstrated a low-cost plastic-based NDR device with highly-reproducible electronic characteristics, and constructed a simple digital circuit from them demonstrating two NDR devices in series acting as an 'AND' logic gate.