Interface defects generated by negative-bias temperature stress in an ultra-thin plasma-nitrided SiON/Si(100) system were characterized by using D2 annealing, conductance-frequency measurements, and electron-spin resonance measurements. D2 annealing was shown to lower negative-bias temperature instability than H2 annealing. Interfacial Si dangling bonds (Pb1 and Pb0 centers), whose density was comparable to an increase in interface trap density, were detected in a negative-bias temperature stress-stressed sample. The negative-bias temperature instability of the plasma-nitrided SiON/Si system was thus shown to occur through Pb depassivation. Furthermore, the nitridation was shown to increase the Pb1/Pb0 density ratio and modify the Pb1 structure. Such a predominance and structural modification of Pb1 centers were presumed to increase negative-bias temperature instability by enhancing the Pb–H dissociation. Although it was suggested that negative-bias temperature stress could also induce non-Pb defects, N dangling bonds did not seem to be included among them.

Interface Defects Responsible for Negative-Bias Temperature Instability in Plasma-Nitrided SiON/Si(100) Systems. S.Fujieda, Y.Miura, M.Saitoh, E.Hasegawa, S.Koyama, K.Ando: Applied Physics Letters, 2003, 82[21], 3677-9