Impact of E-E scattering to the hot carrier degradation of deep submicron NMOSFETs

Abstract

The hot carrier degradation of short channel NMOS-FET's (L L L EFF = = = 0.07-0.10 m) stressed at 2.0 V V DS V DS V DS 2.9 V and a wide V GS V GS V GS range is shown NOT to obey the classic hot carrier "lucky electron model." In the low and mid V GS V GS V GS range, the degradation behavior is better described by an effective electron temperatures model proposed here, which takes e-e scattering effects into account. In the high V GS V GS V GS regime, a further lifetime reduction can be qualitatively explained within this model by the increase in electron concentration at the Si-SiO 2 interface near the drain region.Index Terms-Accelerated stress, e-e scattering, effective electron temperatures, hot carrier degradation, interface state generation, lifetime projection, lucky electron model, reliability.

Effect of electron–electron scattering at an elevated temperature on device lifetime of nanoscale nMOSFETs

“…A possible cause of this substantial increase in DV th under EES stress is the enhanced N it due to electrons in the highenergy tail region of the EED [3]. The EES rate is reported to increase at high values of V g where the concentration of electrons in the channel is high [4]. Moreover, EES enhances device degradation by generating N it [3,5].…”

“…Several researchers have studied CHC effects over a large range of both gate V g and drain voltages V d [4,5]. According to these studies, CHC stress is the worst stress condition for a short channel device [1][2][3][4][5].…”

“…In particular, a few researchers reported severe degradation of devices under low V d with high temperature because of electron-electron scattering (EES) [7][8][9]. According to theoretical studies, the EES rate is dominated by the number of electrons in the high-energy tail of the electron energy distribution (EED) [4]. Moreover, the high-energy tail of the EED is extended by thermal excitation [10].…”

Физические Основы Самосогласованного Моделирования Процессов Генерации Интерфейсных Состояний И Транспорта Горячих Носителей В Транзисторах На Базе Структур Металл-Диэлектрик-Кремний

“…ViennaSHE учи-тывает такие механизмы рассеяния, как ударная иониза-ция, рассеяние на заряженной примеси, поверхностное рассеяние, электрон-фононное и электрон-электронное взаимодействия. Последний тип взаимодействия ока-зывается основным фактором деградации, вызываемой горячими носителями, в транзисторах с длиной канала < 120 нм [20,21].…”

Hydrogen-related defect creation at the Si(100)–SiO2interface of metal-oxide-semiconductor field effect transistors during hot electron stress

“…Lowering the operating voltages from 3.3 to 2.5 V should lead to a factor of 10 20 reduction in degradation. This is not observed in practice which has led some to suggest that an enhancement of the tail of the carrier distribution via carrier-carrier interactions could explain the continuing degradation of low-bias devices [19,20].…”