| AVS 59th Annual International Symposium and Exhibition | |
| Electronic Materials and Processing | Wednesday Sessions |
| Session EM+OX-WeA |
| Session: | Oxides and Dielectrics for Novel Devices and Ultra-dense Memory |
| Presenter: | N. Goldsman, Univ. of Maryland, CoolCAD Electronics LLC |
| Authors: | N. Goldsman, Univ. of Maryland, CoolCAD Electronics LLC F. Yesilkoya, Univ. of Maryland S. Potbhare, CoolCAD Electronics, LLC M. Peckerar, Univ. of Maryland A. Akturk, CoolCAD Electronics, LLC K. Choi, Univ. of Maryland W. Churaman, U.S. Army Research Lab N.K. Dhar, DARPA/MTO |
| Correspondent: | Click to Email |
The rectenna structure we focus on consists of a micro-antenna and a rectifying metal-insulator-metal (MIM) diode for converting electromagnetic wave induced alternating current on the antenna to a direct current. The antenna couples to ambient or directed electromagnetic (EM) radiation, and the diode rectifies the AC signal for DC current and power generation. The frequency or the wavelength of the EM signal dictates the physical dimensions of the antenna, and the operating frequency of the diode. Here one of the main challenges in achieving DC output upon IR radiation is to fabricate a diode capable of operating in the infrared range of frequencies, and more specifically at 30 Terahertz corresponding to 10 micrometer infrared radiation or approximately 300oK. To meet this challenge, we are fabricating metal-insulator-metal diode structures with oxide thicknesses of on the order a couple of nanometers or less.
An application of significant interest is a high resolution, high speed IR imager that can operate at room temperatures. Expanding from a single pixel to a complete large array is a challenge because the added complexity may give rise to electromagnetic coupling between adjacent elements, which needs to be accounted for. In addition, IR imaging, which corresponds to 30 terahertz region of operation, is special because it represents an ‘in-between’ region between radio and optical frequencies. At 10 micron wavelengths, the photons are typically too small in energy to economically convert their AC power into DC using semiconductor or quantum based photodetectors. At the same time, their frequency is too high to utilize standard PN or Schottky barrier diode based rectification. We thus explore the use of a micro-antenna coupled to a MIM diode for AC to DC conversion. A major difficulty here is to develop a diode that responds quickly enough to be forward biased during one part of the AC cycle and reverse biased to the other half of the cycle, without having the parasitic capacitance of the diode short out the signal. The rectenna we are developing uses a Nickel/Nickel-Oxide/Nickel (Ni-NiO-Ni) MIM structure, fabricated and designed using unique modeling and processing techniques.