Greatly suppressed stress-induced shift of GIDL in N 2O-based n-MOSFET's

Abstract

Considerably suppressed gate-induced drain leakage (GIDL) shifts of N 2O-based n-MOSFET's after hot-carrier stress with different gate voltages are observed. The mechanisms involved are studied by dividing gate-oxide traps into sub-interface and bulk-oxide traps, and by means of computer simulations on electric-field distribution and carrier filling of these traps. It is demonstrated that sub-interface and bulk-oxide hole detrapping during stressing are mainly responsible for the respective GIDL shifts under two different stress conditions of V G = 0.5V D and V G = V D, with the effect of the former larger than the latter. In view of this, it is proposed that MOSFET's with N 2O-nitrided or especially N 2O-annealed NH 3-nitrided gate oxide have not only fewer pre-existing sub-interface and bulk-oxide hole traps, but also greatly suppressed generation of hole and neutral electron traps due to the formation of a nitrogen-rich layer near the SiO 2/Si interface through N 2O treatment. © 1998 Published by Elsevier Science Ltd. All rights reserved.