The Characterization of Degradation on various SiON pMOSFET transistors under AC/DC NBTI stress

The characteristics of the degradation on pMOSFETs which have various SiON gate dielectric under AC/DC NBTI stress were studied. The degradation mechanism of NBTI for the device with a room temperature plasma nitridation (PN) is dominated by the generation of interface trap. An additional nitrogen annealing also caused a degradation due to the hole trapping under NBTI. On the other hand, the degradation for the device with PN above 800°C is dominated by the hole trapping under AC/DC NBTI stress. From the experimental results, the NBTI degradation models considering AC/DC operation of the chip were suggested. Base on the model, the simulation of 512Gb NAND chips was performed, and it was confirmed that no chip failure occurred while 15yrs of the actual operation at 110°C.