علي خشنود

Ionizing radiation is preva‎lent in space environments and medical applications such as radiotherapy and X-ray imaging devices and can have detrimental effects on electronic equipment, including significant alterations in the characteristics of CMOS-based devices. This radiation generates holes in the gate oxide, some of which release protons due to hydrogen-containing defects. These protons activate dangling Si-H bonds, leading to the formation of interface traps. The device's threshold voltage shifts due to trapped charges in the gate oxide and charges resulting from Si/SiO2 interface traps. In this thesis, a model of ionizing radiation effects on the generation of interface traps and their energy state density is developed, modeled nonlinearly across the energy band. The modeling incorporates the DCIV technique to determine the energy state density of interface traps and accounts for quantum tunneling and thermal emission effects, which reduce protons near the interface before they chemically react with Si-H bonds, thereby improving model accuracy. Additionally, considering the mechanism of trap-assisted tunneling enhances the model's precision at higher radiation doses. The model achieves an R² of 0.9993, and normalized root mean square error (N-RMSE) of 0.0095 and normalized mean absolute error (N-MAE) of 0.0085 compared to measurements obtained from the IRF620 transistor under irradiation with total ionizing doses (TID) up to 7.8 Mrad (SiO2) by a Cobalt-60 source. Moreover, the model demonstrates an 80.86% and 79.58% improvement in reducing RMSE and MAE, respectively, compared to a previous model with the same measured data. To compensate for threshold voltage shifts, a self-regulating circuit utilizing a body-bias technique for NMOS and PMOS transistors is proposed, which successfully compensates for over 97% of the errors induced by these changes in 0.18 µm CMOS technology. Additionally, simulation software was designed, and a library for this technology was developed.

تابش يونيزان , تله‌هاي رابط , فن‌آوري CMOS , تونل‌زني كوانتومي , باياس بدنه

Ionizing Radiation , Interface Traps , CMOS Technology , Quantum Tunneling , Body Bias

Ali Khoshnoud

Dr. Javad Yavandhasani