M.Sc Thesis

M.Sc StudentCorcos Dan
SubjectCOMS-SOI-MEMS Transistors for Terahertz Imaging
DepartmentDepartment of Electrical and Computer Engineering
Supervisor PROFESSOR EMERITUS Yael Nemirovsky


Termed “The THz Gap” due to lack of access by means of solid-state electronics, this last frontier of the electromagnetic spectrum extends from the upper edge of the microwaves to the infrared, within 1011 to 1013 Hz. THz radiation is non-ionizing and its associated radiation power is low, hence it is considered as safe. At the same time, the THz radiation is penetrating. The combination of penetrating yet safe radiation can be used for a wide range of applications. One such application is medical imaging, since the radiation can penetrate short distance beneath the skin and thus has the potential to spot tumors. Another use is security imaging. THz waves pass through most types of clothing, allowing "intimate" body search at a distance. THz radiation is also useful for real-time spectroscopy of molecules where molecules can be identified by the way they reflect short pulses of THz radiation.

In this research thesis we developed an uncooled passive sensor, dubbed TeraMOS, aimed at detecting radiation in the 0.5-1.5 THz range. This new sensor is intended for monolithic FPAs and it is based on several leading technologies: THz photonics, CMOS-SOI (Silicon-on-Insulator) and MEMS (Micro Electro Mechanical Systems). By introducing the TeraMOS sensor, which may be directly integrated with the CMOS-SOI readout circuitry, we expect to achieve a breakthrough in THz passive imaging both in performance and cost. NEP (Noise Equivalent Power) of the order of 1 pW/Hz1/2 and NETD (Noise Equivalent Temperature Difference) of ~0.5K are expected at room temperature. Absorbing structures based on the Frequency Selective Surface (FSS) theory are integrated with extremely sensitive thermal detectors, using the temperature dependence of the MOS transistors current as a signal.