1. This project will develop passive millimeter-wave (PMMW) detection sensor elements using Si/SiGe technology for direct insertion into passive millimeter-wave camera systems. The development of a new Si/SiGe backwards diode (BD) recently reported by this group (IEEE EDL, 2005 and U.S. patent filed) with ultra-high curvature at zero-bias provides new opportunities for Homeland Security.

This project will investigate and exploit the unique properties of silicon-silicon germanium (Si/SiGe) zero-bias, backward diodes for integration and application in 94 GigaHertz (W-Band) passive, room temperature millimeter wave sensing. By having Si-based detector diodes that operate at W-band, the possibility exists for array architectures that are compatible with wafer scale manufacturing processes such as BiCMOS. Furthermore, the operating frequncy of 94 GHz offers and atmospheric window where millimeter waves permit an observer to see through inclement weather conditions (e.g., rain, fog, smoke) as well as clothing. This feature can offer a high contrast ratio between metallic objects and flesh, which is likened to an X-ray process.

The proposed project will develop a Si-based backward diode that processes the nonlinearity properties of its current compound semiconductor (e.g., InAs, GaSb), and yet be compatible in both structure and epitaxial processes like those employed in CMOS or BiCMOS manufacturing