NBTI of buried oxide layer induced degradation for thin layer SOI field pLDMOS
NBTI of BOX layer induced degradation for thin layer SOI field p channel LDMOS is investigated by experiment, modeling and simulation. Decrease in drain current (Id) under high negative BG voltage (VBG) stressing is observed, which is ascribed to the positive fixed oxide charge and interface charge in BOX layer induced by NBTI. The NBTI conduction modulation model is proposed to elevate the positive charge density (DQp) generation in the BOX layer. The total on resistance is enhanced because of hole concentration in the accumulation layer reduced by the positive charges. Simulated Id shift with applying the corresponding DQp in the BOX layer shows a good fitting with the measured result. Meanwhile, DQp in the BOX layer relaxes the electric field peak at the p drift/n well junction on the SOI/BOX interface, which is responsible for breakdown voltage (BV) increasing.
2016 28th International Symposium on Power Semiconductor Devices and ICs (ISPSD)