Metal-Insulator-Metal Diode Process Development for Energy Harvesting Applications

Persistent powering of electronics, sensors, and autonomous systems on the battlefield has become increasingly important to the U.S. Army. Scavenging energy from local environments reduces the required energy and weight transported to the theater. Black-body radiation could potentially provide a 24-hr energy source for Army systems. MicroNano-scale, metal-insulator- metal MIM tunnel diodes will be developed to provide half-wave rectification as part of a rectenna energy harvesting system, which includes a radiation-collecting antenna, a rectifying MIM tunnel diode, and a storage capacitor. This research addresses the development, fabrication, and characterization of high frequency MIM tunnel diodes for power rectification. Planar platinumtitanium-dioxidetitanium stacks were fabricated with the focus of determining the effects of the insulator thickness on the electrical performance. Insulator thicknesses were studied between 2 nm and 50 nm. The metals were chosen for their high work function difference, and the insulator was chosen for its barrier height and availability. Metals and insulator thin films were sputtered onto silicon substrates with silicon dioxide overlayers. I-V measurements were taken using an electrical characterization system to confirm a non-linear, asymmetric response.