New research results on MIM diodes indicate that they may offer high-speed, higher-frequency alternatives to traditional silicon-based semiconductor devices.
Researchers in the College of Engineering at Oregon State University (Corvallis, OR) have made advances in metal-insulator-metal (MIM) diodes that could eventually render silicon-based integrated circuits (ICs) obsolete, at least for extremely high-speed, high-frequency applications. The diodes are formed of two conducting metal layers with two insulator layers in between. Rather than moving through an insulating material such as silicon, electrons will essentially jump from one conductive layer to another, with corresponding increases in speed and frequency.
Essentially a novel approach to electronic circuits, the research findings on these diodes were published in Applied Physics Letters (a publication of AIP Publishing LLC). According to this report, the step tuning of electrons through the diode could be made possible with the addition of a second insulator layer, forming a metal-insulator-insulator-metal (MIIM) diode. The multiple-insulator-layer approach also allows precise control of diode asymmetry, non-linearity, and rectification at lower voltages.
John F. Conley, Jr., a Professor in the OSU School of Electrical Engineering and Computer Science, comments: “This approach enables us to enhance device operation by creating an additional asymmetry in the tunnel barrier. It gives us another way to engineer quantum mechanical tunneling and moves us closer to the real applications that should be possible with this technology.” The MIM diodes were first introduced only three years ago by the OSU researchers, who are now seeking practical applications for the devices. Research on the MIM/MIIM diodes was supported by National Science Foundation grants, numbers DMR-0805372 and CHE-1102637, and Army Research Laboratory grant number W911NF-07-2-0083.