Total-Ionizing-Dose Irradiation-Induced Dielectric Field Enhancement for High-Voltage SOI LDMOS

Breakdown voltage (BV) shifting behavior induced by total-ionizing-dose (TID) irradiation is investigated for high-voltage SOI LDMOS, in this letter. The BV increase caused by irradiation is present for the first time, and the degradation mechanism is revealed by modeling and simulation. Irradiation-induced electric field modulation exerts an impact on the competition between the lateral BV and vertical BV and results in BV shifting. The dielectric field is enhanced by irradiation-induced positive oxide trapped charges in the BOX layer, which is responsible for the BV increasing after irradiation. A TID radiation hardening approach is proposed so that the lateral BV is required to be properly higher than vertical BV instead of pursuing equality.