Reliability investigation of NLDEMOS in 0.13μm SOICMOS technology

This paper presents new reliability investigations in NLDEMOS transistor in 0.13 mu m SOI CMOS technology. Reliability tests under Hot Carrier Injections (HCI) and OFF state regimes show a strong dependence with the drain extension length L-ext. The use of borderless nitride in order to create contacts is suspected to be the origin of degradation. Mobiles charges in this nitride can move under electrical field in HCI or OFF-state stress and then modulate the conductivity of the drain extension region. With a reverse electrical field applied after OFF-state (drain) or HCI stress, we show that the degraded NLDEMOS can completely recover its initial performances. A novel nitride borderless with a decrease of SiH4 rate during process step shows a strong reliability improvement due to the decrease of dangling bonds at SiPROT/bordeless nitride interface.