Uncooled nanoscale infrared high-speed sensors for missile seeker applications

Multicolor capabilities, high detectivity, and quick response are highly important for advanced infrared sensor systems. Photodiodes made of narrow-band semiconductors are widely used in such applications. However, the photodiodes require cryogenic temperatures and are expensive. Less expensive uncooled bolometric detectors are less sensitive, significantly slower, and have no multicolor capability. In order to overcome abovementioned obstacles, we have been developing infrared detectors consisting of a dielectric rod antenna (DRA) in conjunction with a nanoscale metal-insulator-metal (MIM) tunnel diode. In these assemblies, the DRA amplifies the incident electromagnetic radiation, and the induced infrared frequency voltage is rectified by the MIM diode connected between the DRA and the ground electrically conductive plate, thus transforming the electromagnetic energy into a useful electrical signal. Because of the antenna's directional selectivity and using an MIM diode having the extremely low tunneling time and nanometer size contact area, such a detector can respond at terahertz frequencies at room temperature. It has been shown that DRAs made of high resistivity silicon posses low loss and enhanced gain at long infrared wavelengths. The proposed approach demonstrates the inherent benefits of a nanoscale device manufacturing technique that is compatible with existing CMOS technology, which may lead to the design of low cost sensors and/or sensor arrays for use in military and commercial applications.