Wk. Henson et al., Observation of oxide breakdown and its effects on the characteristics of ultra-thin-oxide nMOSFET's, IEEE ELEC D, 20(12), 1999, pp. 605-607
Ultra-thin gate oxide breakdown in nMOSFET's has been studied for an oxide
thickness of 1.5 nm using constant voltage stressing. The pre- and post-oxi
de breakdown characteristics of the device have been compared, and the resu
lts have shown a strong dependence on the breakdown locations, The oxide br
eakdown near the source/drain-to-gate overlap regions was found to be more
severe on the post-breakdown characteristics of the device than breakdown i
n the channel. This observation may be related to the dependence of breakdo
wn on the distribution of electric field and areas of different regions wit
hin the nMOSFET under stress.