Safe operating condition and lifetime estimation in p-MOSFET device due to Negative Bias Temperature Instability

Abstract

Negative Bias Temperature Instability is a serious reliability concerns for modern p-MOSFETs with Effective Oxide Thickness less than 2nm. This reliability problem can severely affect the device performance and limit the lifetime of the device. This paper is focusing on the safe operating condition and lifetime estimation of the p-MOSFET device with regard to NBTI effects. To explore the variation of safe operating condition and lifetime estimation, p-MOSFET having EOT 1nm was systematically simulated by varying the hydrogen species, measurement delay, stress temperature and stress gate voltage. The hydrogen species is varied based on molecular and atomic hydrogen. The measurement delay is simulated based on the measurement delay as found in literature. The stress temperature is varied from 80°C to 100°C and the stress gate voltage is varied from −0.5V to −1V. The simulation result shows that the safe operating voltage for molecular hydrogen and atomic hydrogen is almost the same but the device lifetime estimation for molecular hydrogen is less than atomic hydrogen. For higher measurement delay, the lifetime estimation is higher compare to no delay while the safe operating voltage estimated for 5 years lifetime shows no significant different. The lifetime estimation for variation of temperature shows that the higher stress temperature contributes to more reduction in the device lifetime. The safe operating voltage condition is decreases as the temperature increases. Meanwhile, for the simulated stress voltage, the lifetime estimation of the device is increases as the absolute value of the stress voltage decreases.