Investigation of Self-Heating Effect on Hot Carrier Degradation in Multiple-Fin SOI FinFETs

In this letter, the impact of self-heating effect (SHE) on hot carrier degradation (HCD) in multiple-fin silicon-on-insulator (SOI) FinFETs was investigated. First, the ac conductance method has been utilized to extract the thermal resistance (Rth) of SOI FinFETs with different fin numbers. Then, both dc and ac stresses are applied on the gate and drain of transistors with the source grounded to characterize the HCD. It is found that the device with large fin number demonstrates high-temperature rise caused by SHE, which results in the enhanced generation of oxide bulk trapped charges. Thus, the SHE aggravates the HCD significantly. The influence of SHE on HCD is mitigated when the frequency of ac stress is above 10 MHz. Therefore, special attention to the SHE on HCD must be paid for accurate HCD prediction in FinFETs.