Continuing degradation of the SiO2/Si interface after hot hole stress

Abstract

This article reports new experimental results on the continuing interface trap generation post-hot hole injection and investigates the generation mechanism. The generation post-hole injection is found to be two orders of magnitude slower than that post-irradiation and cannot be satisfactorily explained by the transportation of hydrogen species across the gate oxide. The role played by the recombination of trapped holes with free electrons is examined. There is a lack of correlation between the trapped hole removal and the interface trap creation, which is against the prediction of the trapped hole conversion model. The results indicate that the interface traps generated during and post-stress originate from two different defects. The defect responsible for post-stress generation is excited by hole injection and then converted into an interface trap if a positive gate bias is applied. It is found that generation in a poly-Si gated metal-oxide-semiconductor field effect transistor behaves differently from that in an Al-gated device. The possible causes for this difference are discussed.

Study of temperature dependence of positive charge generation in thin dielectric film of MOS structure under high-fields

“…The analysis of the experimental data, presented in Fig. 3, shows that thermal ionization of a part of the trapped holes takes place, which is in a good agreement with literature [3,4].…”

“…Currently, despite of the large amount of articles, describing this phenomenon, both the nature of positive charge, as well as its generation mechanism, remains poorly understood. As possible mechanisms, leading to positive charge generation, the band-to-band impact ionization in SiO 2 film causing the hole generation [1], the hole injection from anode [2], hydrogen redistribution [3,4], etc. have been suggested.…”

Behavior of hot hole stressedSiO2/Si interface at elevated temperature

“…16 However, none of them can satisfactorily explain our recent results. 13 These results show that there are two types of defects at the SiO 2 /Si interface. One of them is converted into interface states directly during the hole injection.…”

“…9 After hole injection is terminated, the generation of interface states can continue. 1,13 This post-stress degradation reduces device lifetime 1 and its physical mechanism is still not clear. The models proposed for explaining the post-stress degradation include the hydrogen transportation across the oxide, 6 the trapped hole conversion, 14,15 and H 2 cracking.…”

Physico-chemical processes in metal–oxide–semiconductor transistors with thick gate oxide during high electric field stress

“…A complete study of the mechanisms responsible for defect creation in metal-oxide-semiconductor field-effect transistors (MOSFETs) during the high electric field stress (HEFS), (a very important stress type [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]) has been pursued. The idea is to give a complete analysis of the physicochemical processes in the gate oxide (SiO 2 ) and at the gate oxide/substrate (SiO 2 /Si) interface during HEFS, since it could not been found in the literature.…”