STUDY OF MOS GATE DIELECTRIC-BREAKDOWN DUE TO DRAIN AVALANCHE BREAKDOWN

This work reports the effects of drain impact ionization injection on the gate dielectric breakdown. Results show that due to the high energ y hot carrier injection, the gate oxide can break drown twice ai a low oxide electric field (<1.2 MV/cm). The first breakdown occurs simulta neously with the drain avalanche breakdown whereas the second breakdow n occurs beyond the drain breakdown. It is further identified that the first gate oxide breakdown is governed by the thermionic emission of hot electrons at low oxide fields (<1.0 MV/cm) and by the scattering p rocesses at higher oxide fields. The second breakdown is attributed to the Fowler-Nordheim (F-N) tunneling. (C) 1998 Elsevier Science Ltd. A ll rights reserved.