Interface defects responsible for negative-bias temperature instability in plasma-nitrided SiON/Si(100) systems

Abstract

Interface defects generated by negative-bias temperature stress (NBTS) in an ultrathin 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 (NBTI) than H2 annealing. Interfacial Si dangling bonds (Pb1 and Pb0 centers), whose density is comparable to an increase in interface trap density, were detected in a NBTS-stressed sample. The NBTI 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 are presumed to increase NBTI by enhancing the Pb–H dissociation. Although we suggest that NBTS may also induce non-Pb defects, nitrogen dangling bonds do not seem to be included in them.

Positive charge generation due to species of hydrogen during NBTI phenomenon in pMOSFETs with ultra-thin SiON gate dielectrics

“…Thus, some other phenomenon that decreases DV th while keeping DS unchanged must occur. We consider that this phenomenon is electron trapping of positive charges induced by hydrogen atoms captured in the gate dielectric by reaction (2). This reveals the following two points: (1) positive charges are generated during NBTI phenomenon even in the case of ultra-thin gate oxynitride, and (2) this kind of positive charges can be neutralized by trapping electrons.…”

“…Although it is impossible to extract the value of flatband voltage from such measurements, the value of midgap voltage (V mg ) can be extracted. Since an NBTI-induced interface trap is identified with the so-called ''Pb center'' that is known to be able to be charged either positively or negatively [1,2], we consider that the value of V mg represents the number of the NBTI-induced positive charges in the gate dielectric. As shown in Fig.…”

“…NBTI is believed to be caused by a hydrogen release reaction at the gate-dielectric/substrate interface [1,2]. Jeppson et al stated that NBTI is limited by hydrogen diffusion mechanisms and this model has been widely accepted [3].…”

Transistor Degradations in Very Large-Scale-Integrated CMOS Technologies

“…Interface trap (N it ) generation is attributed to a breaking of Si-Hb o n d sb y holes [35], or by protons [36], which leave behind the amphoteric trivalent Si 3 Si…”

Silicon Nanocrystal Flash Memory

“…Nitrogen atoms incorporated into a SiO 2 thin film is known to be the major reason of reliability degradation [85,86]. However, in the SN-nc-Si dot memory, the utilized silicon nitride thin film is not the tunnel barrier but the memory node, which is located on the top of nc-Si core.…”