Reliability characteristics of metal-oxide-semiconductor capacitors with 0.72nm equivalent-oxide-thickness LaO/HfO2 stacked gate dielectrics

Liu, Chuan–Hsi; Hsu, Hsiang‐Chin; Chen, Hung−Wen; Juan, Pi-Chun; Wang, Mu‐Chun; Cheng, Chin-Po; Huang, Heng-Sheng

doi:10.1016/j.mee.2011.04.009

Cited by 4 publications

(1 citation statement)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Studies of BD characteristics of high-k stacks are complicated by their double-layer structure due to the presence of lower-k SiO 2 -like interfacial layer at Si. Generally, the reliability is affected by a number of factors such as microstructure and thickness of both the high-k layer and the interface region, their possible interaction, stress polarity, gate type and its area [6,[10][11][12][13][14][15][16][17]. It was suggested that the degradation mechanism in highk dielectrics is dominated by an 'extrinsic' mechanism in contrast to so-called intrinsic BD which is not related to process-induced or other extraneous defects.…”

Section: Introductionmentioning

confidence: 99%

Time-dependent dielectric breakdown in pure and lightly Al-doped Ta₂O₅stacks

Atanassova¹,

Stojadinović²,

Spassov³

et al. 2013

Semicond. Sci. Technol.

View full text Add to dashboard Cite

The time-dependent dielectric breakdown (TDDB) characteristics of 7 nm pure and lightly Al-doped Ta 2 O 5 (equivalent oxide thickness of 2.2 and 1.5 nm, respectively) with W gate electrodes in MOS capacitor configuration are studied using gate injection and constant voltage stress. The effect of both the process-induced defects and the dopant on the breakdown distribution, and on the extracted Weibull slope values, are discussed. The pre-existing traps which provoke weak spots dictate early breakdowns. Their effect is compounded of both the stress-induced new traps generation (percolation model is valid) and the inevitable lower-k interface layer in the region with long time-to-breakdown. The domination of one of these competitive effects defines the mechanism of degradation: the trapping at pre-existing traps appears to dominate in Ta 2 O 5 ; Al doping reduces defects in Ta 2 O 5 , the generation of new traps prevails over the charge trapping in the doped samples, and the mechanism of breakdown is more adequate to the percolation concept. The doping of high-k Ta 2 O 5 even with small amount (5 at.%) may serve as an engineering solution for improving its TDDB characteristics and reliability.

show abstract